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Exhibit MSD 89I - Solids Handling Master Plan Phase Technical Memorandum UpdateMetropolitan St. Louis Sewer District Solids Handling Technical Memorandum Fluidized Bed Incinerators Project 12565 June 2018 Exhibit MSD 89I Page 2 of 24 Table of Contents 1. Introduction ..................................................................................................................................... 5 1.1 Purpose of the Technical Memorandum ......................................................................................... 5 1.2 District Overview ............................................................................................................................ 5 2. Background Information ................................................................................................................ 6 2.1 Existing Sludge Handling ................................................................................................................ 6 2.1.1 Bissell Point WWTF .................................................................................................................. 7 2.1.2 Lemay WWTF ........................................................................................................................... 8 2.1.3 Lower Meramec WWTF ............................................................................................................ 9 2.1.4 Grand Glaize WWTF ................................................................................................................. 9 2.2 Solids Handling Alternatives ........................................................................................................ 10 2.2.1 Option #1 – Master Regional ................................................................................................... 10 2.2.2 Option #2 – Regional Lower Meramec WWTF Digesters ...................................................... 10 2.2.3 Option #3 – Sub-Regional Lower Meramec & Grand Glaize WWTFs Digesters .................. 11 2.2.4 Option #4 – Sub-Regional Bissell Point & Lemay WWTFs Incineration ............................... 11 2.3 Related Studies .............................................................................................................................. 11 2.3.1 Comprehensive Solids Handling Master Plan ......................................................................... 11 2.3.2 Comprehensive Ammonia and Nutrient Removal Master Plan ............................................... 11 2.3.3 Grand Glaize Sludge Odor Reduction ..................................................................................... 11 2.3.4 Lemay CSO Outfall 063 High Rate Clarification Facility Treatability Study ......................... 11 2.3.5 Prospect Hill Landfill Vertical Expansion Permit Modification ............................................. 11 2.3.6 Wastewater Treatment Facility Capital Improvement Plan ..................................................... 12 3. Alternatives Evaluation ................................................................................................................ 12 3.1 Permitting Feasibility .................................................................................................................... 12 3.2 Environmental Concerns ............................................................................................................... 12 3.2.1 Transferring Sludge Between Facilities ................................................................................... 12 3.2.2 Future Air Regulations ............................................................................................................. 13 3.2.3 Landfilling Sludge ................................................................................................................... 13 3.2.4 Incinerator Ash Disposal .......................................................................................................... 13 3.2.5 Sludge Land Application ......................................................................................................... 14 3.2.6 Nutrient Control ....................................................................................................................... 14 3.3 Cost Evaluation ............................................................................................................................. 16 3.3.1 Option #1 – Master Regional ................................................................................................... 17 3.3.2 Option #2 – Regional Lower Meramec WWTF Digesters ...................................................... 17 3.3.3 Option #3 – Sub-Regional Lower Meramec & Grand Glaize WWTFs Digesters .................. 17 3.3.4 Option #4 – Sub-Regional Bissell Point & Lemay WWTFs Incineration ............................... 18 3.4 Selected Alternative ...................................................................................................................... 18 4. Option #4 Planning Considerations ............................................................................................. 19 4.1 FBI Sizing ..................................................................................................................................... 19 4.2 Advanced Emissions Controls ...................................................................................................... 20 5. Related CIRP Projects .................................................................................................................. 21 5.1 Nutrient Removal Facilities .......................................................................................................... 21 5.2 Prospect Hill Landfill .................................................................................................................... 21 Page 3 of 24 5.3 Lower Meramec WWTF to Fenton WWTF Tunnel .................................................................... 21 5.4 Sludge Forcemain Lower Meramec WWTF to Lemay WWTF.................................................... 22 5.5 Sludge Forcemain Grand Glaize to Fenton ................................................................................... 22 5.6 Fenton Wastewater Treatment Facility Elimination ..................................................................... 22 5.7 HVAC Upgrades at Lemay and Bissell Point WWTFs ................................................................ 22 5.8 Bissell Point WWTF Redundant Sludge ....................................................................................... 22 5.9 Lower Meramec WWTF PH II ..................................................................................................... 22 5.10 Coldwater WWTF Redundant Sludge Forcemain ...................................................................... 23 5.11 Lemay Facility Upgrades (Phase 2) ............................................................................................ 23 6. Conclusions and Recommendations ............................................................................................ 23 6.1 Bissell Point and Lemay WWTFs ................................................................................................. 23 6.2 Coldwater WWTF ......................................................................................................................... 23 6.3 Missouri River WWTF .................................................................................................................. 24 6.4 Grand Glaize WWTF .................................................................................................................... 24 6.5 Fenton WWTF ............................................................................................................................... 24 6.6 Lower Meramec WWTF ............................................................................................................... 24 Page 4 of 24 APPENDIX Appendix A – Incineration Facility Alternatives Appendix B – County Facility Alternatives Appendix C – Solids Handling MP TM-6 (Regional Bissell) Appendix D – Solids Handling MP TM-1 (Sub-Regional Bissell) Appendix E – Solids Handling MP TM-2 (Sub-Regional Lemay) Appendix F – Solids Handling MP TM-9 (Opinion of Costs) Appendix G – Grand Glaize Sludge Odor Reduction Study Appendix H – Air Emissions Analysis Appendix I – Planning Studies on Forcemain Alignments and Cost Estimates Appendix J – FBI Alternatives Cost and Application Notes Page 5 of 24 1. Introduction 1.1 Purpose of the Technical Memorandum In 2011, MSD commissioned the Comprehensive Solids Handling Master Plan (SMP) to evaluate long-term sewage sludge handling options for MSD’s wastewater treatment plants. Since that time, new emission standards (from Clean Air Act Section 129) were promulgated for sewage sludge incinerators, which impacted MSD’s long-term plan. MSD recognized that these regulatory constraints would prohibit further improvements to its existing sewage sludge incinerators, which are near the end of their useful life. Therefore, MSD re-evaluated the SMP alternatives and recommended an approach to move forward in the Capital Improvement Replacement Program (CIRP) with a solids handling solution. In 2017, MSD proposed a material modification in the Consent Decree to postpone the Lower/Middle River Des Peres CSO Tunnel in order to accelerate plans for constructing new solids handling facilities. This technical memorandum summarizes MSD’s planning efforts for developing an updated solids handling solution. MSD’s planning team included a joint Engineering-Operations effort led by Cathy Politte, Bruce Litzsinger and Jay Hoskins, and included the following team members: Bob Dobrynski, Cindy Cullen, Christine Palmer, Rob Segar, Karen Janson, and Rebecca Losli. Periodic presentations were given to the Engineering and Operations Department Directors, General Counsel, Communications Manager, and Executive Director for final decision-making. 1.2 District Overview MSD's service area encompasses approximately 520 square miles, including all 66 square miles of the City of St. Louis, and 454 square miles (approximately 87%) of St. Louis County. The current population served by MSD is approximately 1.3 million people. MSD owns and operates the System, which consists of wastewater, stormwater and combined collection sewers (9,520 miles of pipe), 278 pumping stations, and seven wastewater treatment facilities. As seen in Figure 1-1, MSD’s jurisdictional area is divided into five Service Areas. The Coldwater Creek, Missouri River, and Bissell Point Service Areas are served by the Coldwater Creek, Missouri River, and Bissell Point Wastewater Treatment Facilities (WWTFs), respectively. The River Des Peres Service Area is served by the Lemay WWTF. The Lower Meramec Service Area is served by Grand Glaize, Fenton, and Lower Meramec WWTFs. In total, these facilities treat an average of over 350 million gallons of wastewater per day. The Bissell Point and Lemay WWTFs are the District's two largest facilities. Page 6 of 24 Figure 1-1. MSD Wastewater Treatment Facilities 2. Background Information 2.1 Existing Sludge Handling The following sections provide information on existing sludge handling at the Bissell Point, Lemay, Lower Meramec, and Grand Glaize WWTFs. Missouri River and Fenton WWTFs are not included because these plants will not be updated for the solids handling alternatives described in Section 2.2. Missouri River WWTF will continue to independently dispose of its digested solids without any need for upgrades. Fenton WWTF is scheduled to be decommissioned (see Project 12170 in Section 5.6). Page 7 of 24 2.1.1 Bissell Point WWTF The Bissell Point WWTF was commissioned in 1970 with a permitted design flow of 150 mgd. Wet-weather flow that can be treated through preliminary and primary treatment is 350 mgd, and 250 mgd can be treated through secondary treatment. The plant has both trickling filters and activated sludge for secondary treatment. However, the activated sludge system is currently not in use because the trickling filters provide adequate treatment. The WWTF generates primary solids and tricking filter solids, which are co- thickened in primary clarifiers to approximately three percent total solids. The Bissell Point Watershed also receives thickened undigested solids pumped into the collection system from the Coldwater Creek WWTF. A schematic of the Bissell Point solids handling processes including Multiple Hearth Incineration (MHI) is provided in Figure 2-1. Figure 2-1. Bissell Point WWTF Process Flow Diagram Grease, septage, and other hauled wastes from the St. Louis region are trucked to the Bissell Point WWTF and unloaded via manholes upstream of the pre-aeration tanks. Grease and scum are collected from the primary clarifiers, pumped to scum thickeners, and then conveyed to the sludge wells where they are combined with the co-thickened sludge from the primary clarifiers. The combined solids are dewatered to approximately 30 % TS using belt filter presses (BFP) and polymer. Bottom sludge from the scum concentrators and filtrate from the BFPs are combined and returned to the primary clarifiers. The dewatered cake from the BFPs is discharged to belt conveyors, which convey the cake to equalization bins. Hydraulic piston pumps (Schwing) feed the dewatered cake from the equalization bins to the multiple hearth incinerators (MHIs). The MHIs thermally oxidize the dewatered cake to produce ash and exhaust gases. The exhaust gases from the incinerators are treated using wet scrubbers and the ash is sluiced and pumped to the ash lagoons located on site. The ash lagoons are periodically gravity drained/evaporated and dry ash is excavated, and the ash is hauled to the Prospect Hill Landfill. The Bissell Point WWTP has a design sludge production of 110,000 dry tons per year (300 dtpd). The Page 8 of 24 solids processes include: • Co-thickening of primary and secondary solids in primary clarifiers. • Twelve gravity belt thickeners (not in use). • Fifteen total high-solids belt filter presses for dewatering (2 of which are decommissioned). • Six total live-bottom feed bins with screw conveyors (only 5 bins are useable). • Six multiple hearth incinerators with heat recovery (two of which are decommissioned). • Two ash slurry ponds. • Ash disposal at the Prospect Hill Landfill. 2.1.2 Lemay WWTF The Lemay WWTF is an activated sludge facility near the confluence of the River Des Peres and Mississippi River. The plant has a secondary treatment design capacity of 210 mgd and a peak wet- weather capacity of 340 mgd. The plant began operating in 1968 as a primary treatment facility with incineration for solids destruction. Construction of the secondary treatment facilities began with the aeration basins in 1977 and secondary clarifiers in 1980. Full secondary treatment began in 1985. Recent expansions of treatment facilities have increased the capacity to current levels. The major treatment components consist of four detritus grit tanks, five comminutors, two pre-aeration tanks, eight primary clarifiers, eight step-feed aeration tanks, and twelve final clarifiers. The recent wet weather expansion consisted of four additional primary clarifiers, two grit basins with channel grinders, a primary sludge pump station, and a grit handling facility. High-rate solids removal may also be used in the future (see Section 2.3.4). Figure 2-2 is a schematic of the solids processes with energy recovery. Figure 2-2. Lemay WWTF Solids Processing Page 9 of 24 The Lemay WWTP has a design sludge production of 73,000 dry tons per year (200 dtpd). The solids handling processes include: • Co-thickening of primary and secondary solids in primary clarifiers. • Six high-solids Ashbrook Winklepress belt filter presses for dewatering. • Two live-bottom feed bins with screw conveyors. • Four multiple hearth incinerators with heat recovery (one MHI is decommissioned). • Three ash slurry ponds. • Ash disposal at the Prospect Hill Landfill. 2.1.3 Lower Meramec WWTF The Lower Meramec WWTF was commissioned in 2007 with a permitted capacity of 15 mgd. This facility includes coarse screens, fine screens, primary clarification, biological trickling filters, secondary clarification, chlorine disinfection/bisulfate dechlorination, and a gravity outfall to the Mississippi River. The facility has a design sludge production of 3,450 dry tons per year. The solids process includes the degritting of primary solids and WAS which is followed by gravity thickening and then belt filter presses, operating five days per week. Refer to Figure 2-3 for an illustration of the Lower Meramec solids processing. Figure 2-3. Lower Meramec WWTF Solids Processing 2.1.4 Grand Glaize WWTF The Grand Glaize WWTP is an oxidation basin plant that was commissioned in 1986 with a permitted design capacity of 16 mgd. The plant was recently expanded to accommodate a design flow of 21 mgd. The improvements included the addition of primary clarifiers, additional aeration basins, and final clarifiers to meet the increased flows. A second belt filter press was also installed with the improvements. The plant has a design sludge production of 3,250 dry tons per year. Major sludge process systems at the plant include gravity sludge thickeners and belt filter presses. There is no dewatered sludge storage except in trucks. Stabilization of solids is not performed at the plant. Sludge is disposed offsite by truck Page 10 of 24 to landfill, incineration, composting, or land application. Refer to Figure 2-4 for an illustration of the major sludge components. Figure 2-4. Grand Glaize WWTF Solids Processing 2.2 Solids Handling Alternatives The planning team evaluated the SMP and other related studies, which are detailed in Section 2.3, and ultimately identified four future sludge handling alternatives for further consideration. These alternatives were originally developed in the SMP but were updated by the planning team to meet current needs. During the planning effort, many other ideas for innovative solutions were discussed, such as using sludge for energy recovery or land application of sludge. MSD used both of these approaches at Missouri River and Coldwater WWTFs. However, to-date, these alternatives are not particularly economical or problem free for the long-term. The four sludge handling alternatives selected for evaluation are described below. In all options, Missouri River WWTF would continue to independently dispose of its digested solids without any need for upgrades. These options also assume the decommissioning of the Fenton WWTF. 2.2.1 Option #1 – Master Regional Option #1 locates all future incineration at the Bissell Point WWTF with the construction of three 120 dry tons per day (dtpd) fluidized bed incinerators (FBIs), a dewatering centrifuge facility, and a solids receiving facility. Appendix A describes the facilities in more detail. Bissell Point WWTF would handle sludge from all WWTFs, apart from the Missouri River WWTF. A new sludge forcemain would be constructed from the Grand Glaize WWTF to the Fenton drop shaft on the Lower Meramec Tunnel (see Appendix B). A second new forcemain would convey Lower Meramec Service Area solids to Lemay WWTF (see Appendix B). Lemay and Lower Meramec solids would be pumped through a new forcemain to the regional Bissell Point Solids Handling facility for dewatering and incineration 2.2.2 Option #2 – Regional Lower Meramec WWTF Digesters This option retains the use of FBIs and centrifuge dewatering at the Bissell Point WWTF to handle sludge from Bissell Point, Coldwater, and Lemay WWTFs. Bissell Point WWTF would have one Page 11 of 24 70 dtpd and two 120 dtpd incinerators. New digestion facilities would be constructed at Lower Meramec WTTF to handle sludge from the entire Lower Meramec Watershed. The stabilized sludge cake would be hauled to a landfill. Appendix A and Appendix B describe the facilities in more detail. 2.2.3 Option #3 – Sub-Regional Lower Meramec & Grand Glaize WWTFs Digesters This option retains the use of FBIs and centrifuge dewatering at the Bissell Point WWTF to handle sludge from Bissell Point, Coldwater, and Lemay WWTFs. Bissell Point WWTF would have two 120 dtpd and one 70 dtpd incinerators. New digestion facilities would be constructed at both the Lower Meramec and Grand Glaize WTTFs to handle sludge from the Lower Meramec Watershed. The stabilized sludge cake would be hauled to a landfill. Appendix A and Appendix B describe the facilities in more detail. 2.2.4 Option #4 – Sub-Regional Bissell Point & Lemay WWTFs Incineration This option calls for sub-regional incineration and solids handling facilities, with two 120 dtpd FBIs at Bissell Point WWTF and two 70 dtpd FBIs at Lemay WWTF. The Bissell Point WWTF FBIs would handle sludge from Bissell Point and Coldwater WWTFs, and the Lemay WWTF FBIs would handle sludge from Lemay WWTF and the Lower Meramec Watershed. Appendix A describes the facilities in more detail. The Lower Meramec forcemains from Option #1 would be needed to transfer sludge to Lemay WWTF. 2.3 Related Studies The planning team used the following studies to inform the decision making process for solids handling. These studies should also be evaluated by the selected design engineer. 2.3.1 Comprehensive Solids Handling Master Plan The SMP (MSD Project 10373) was reported in two phases. The 2009 Phase I report consisted of nine technical memoranda which documented existing sludge handling conditions at MSD’s treatment plants. The 2011 Phase II report contained future sludge disposal alternatives. 2.3.2 Comprehensive Ammonia and Nutrient Removal Master Plan The Comprehensive Ammonia and Nutrient Removal Master Plan (MSD Project 12070) was reported in two groups. The Task Group 1 report was delivered on 11/4/16 and consisted of six technical memos which focused on existing conditions related to nutrient removal at MSD’s treatment plants. The Task Group 2 report will be finalized in mid-2018 and will focus on future treatment options for nutrient removal. See Section 5.1 for more details. 2.3.3 Grand Glaize Sludge Odor Reduction The County Solids Pre-Design Report, dated 1/26/18, was prepared as part of the Grand Glaize Odor Reduction Project (12725). The report proposed short- and long-term alternatives to landfilling raw sludge from the County treatment facilities. The report also provided costs for digestion facilities, landfilling digested sludge, and current incineration costs. 2.3.4 Lemay CSO Outfall 063 High Rate Clarification Facility Treatability Study MSD is planning to construct the Lower/Middle Des Peres (LMRDP) CSO Storage Tunnel to alleviate combined sewer overflow that is currently discharged directly to the River Des Peres. The storage tunnel will direct the flow to the Lemay WWTF, where up to 100 MGD of wet-weather flow will be diverted for treatment by a high rate clarification facility (Project 11818). To support Project 11818, the Lemay CSO Outfall 063 High Rate Clarification Facility Treatability Study provides information on water quality and performance of the proposed high rate treatment technologies. 2.3.5 Prospect Hill Landfill Vertical Expansion Permit Modification The Prospect Hill Landfill Vertical Expansion permit application to MDNR sought to increase the capacity of the Prospect Hill Landfill, which is owned and operated by MSD in north St. Louis. The Page 12 of 24 application, cover letter, plans, and report are dated 12/4/15. See Project 11094 in Section 5.2 for more information. 2.3.6 Wastewater Treatment Facility Capital Improvement Plan The Wastewater Treatment Facility Capital Improvement Plan, dated February 2014, was prepared in support of the Watershed Facility Planning Phase II Project (10230) to examine the future capital needs of each treatment facility. Over 87% of future capital needs were for regulatory compliance for expected nutrient limits. 3. Alternatives Evaluation The planning team evaluated the four sludge handling alternatives to determine the most environmentally friendly and economically viable solution. The following sections provide details on the planning team’s assessment of each option in terms of: • Permitting Feasibility, • Environmental Concerns, and • Cost. 3.1 Permitting Feasibility The planning team conducted a preliminary air emission assessment (see Appendix H) to evaluate the feasibility of air permitting for each solid handling option. The assessment indicated that permitting could be achieved for all options; however, Option #1 appeared to be the least straightforward alternative to permit. First, from an environmental air permitting perspective, the regional facility could be considered a Major Source of air pollution, mainly due to the necessary increase in sludge throughput at the Bissell WWTF. Secondly, there could be Environmental Justice and community perception concerns related to bringing sewage sludge from the entire District into the City of St. Louis. A significant amount of community and stakeholder coordination effort would be needed to justify such a drastic strategic departure from MSD’s current solids handling. 3.2 Environmental Concerns The planning team investigated other environmental concerns which are described below. 3.2.1 Transferring Sludge Between Facilities MSD currently hauls sludge between MSD facilities, to land application sites, to composting sites, and to sanitary landfills. However, MSD management has concerns with hauling raw sludge as a long-term disposal solution due to potential impacts to the environment and MSD’s public image. These concerns are related to: 1. The potential for sludge spills in public; 2. The perception of trucking as not being an environmentally sustainable operation; and 3. Current experience with numerous odor complaints while hauling to the landfills. The planning team investigated whether it would be feasible to use sludge forcemains to transfer sludge between WWTFs instead of hauling. The SMP indicated that hauling and the use of forcemains and pump stations had similar costs for transferring sludge from Lemay WWTF to the Bissell Point WWTF. Additionally, the use of pump stations and forcemains would eliminate manned sludge handling operations at three existing facilities. Thus, the planning team concluded that hauling raw sludge should not be relied upon as a primary sludge handling option and that all sludge hauling should be minimized. The direction for this approach was viewed as desirable based on the success of managing Coldwater WWTF sludge in this manner by pumping sludge from Coldwater WWTF into the Bissell Point collection system. Page 13 of 24 Additional details on the selected sludge forcemain alignments can be found in Appendix I. The team reviewed the SMP to develop alignments for the four sludge handling alternatives. For Options #1, #2, and #3, the team had concerns with the SMP alignment that called for discharge of the sludge into the Barton street drop shaft. This SMP alignment would likely have CSO impacts during wet weather by introducing the sludge along the riverfront. Thus, the planning team evaluated an alternative forcemain alignment along Jefferson Avenue that would eliminate the CSO concerns. However, this alignment would also be extremely difficult and undesirable to construct through the middle of the City in a congested area with limited space and numerous conflicts. Option #4 presented the most feasible alternative for constructing sludge forcemains and pump stations. 3.2.2 Future Air Regulations The planning team investigated whether the District should anticipate any future air regulatory changes that would impact the solids handling solution. The team found that the 40 CFR Part 60, Subpart LLLL standards, which set controls and emissions from new and existing sewage sludge incinerators, are unlikely to become more stringent for some time. There are a couple reasons. First, through Executive Order 13771, President Trump effectually “paused” the promulgation of new regulations. Through this order, EPA would be required to rescind two existing regulations to promulgate one new regulation. For EPA to do this would be unprecedented. Secondly, because the SSI regulations were fairly recently revised, it is more likely that EPA will focus on other issues in the foreseeable future. The team also looked at potential changes to greenhouse gas regulations that could potentially impact the FBIs. The team found that, for communities that operate SSI units, it is unclear to what extent CO2 emissions from SSI units will be regulated in the future. The EPA and States do not presently regulate carbon dioxide (CO2) like other conventional pollutants. Under the Obama (U.S.) administration and Nixon (MO) administration, EPA and DNR set goals for Missouri to reduce CO2 emissions. However, both the Trump and Greitens administrations have “paused” establishing new regulations generally, and it seems unlikely that these goals will be implemented soon. Environmental and other non- governmental organizations (NGOs) could litigate with permittees, DNR, and/or EPA about meeting these CO2 emissions goals. When CO2 emission reductions are required, emissions from SSI units may be a lower priority for new regulations because other fixed sources, like power plants, have much greater CO2 emissions compared to SSI units. 3.2.3 Landfilling Sludge Although MSD plans to minimize landfilling raw sludge, landfilling of sludge is and should continue to be a disposal option. Because landfills are required to control odors at the perimeter of their facilities, historically the main issue is odor produced by the transportation of undigested sludge entering the landfill. If these odors are not managed, contracted landfills may refuse to accept MSD’s sludge. While wholesale refusal seems unlikely, there is uncertainty and at times MSD operations have been disrupted by intermittent refusal of MSD sludge by contracted landfills. Recently, the City of Alton approached MSD about a biosolids digestion and biogas generation project that Alton is pursuing. Construction of the Alton facility has not begun and it would not be available to MSD for several more years. Alton could be an attractive option for sludges generated from the Lower Meramec, Grand Glaize, and Fenton facilities; however, Alton is not a holistic solution for all of the sludge that MSD generates. 3.2.4 Incinerator Ash Disposal MSD currently disposes of incinerated sludge (i.e., ash) at the Prospect Hill Landfill. As noted in the SMP Phase I report, landfill capacity either needs to be expanded, the ash needs to be hauled to another landfill, or the ash needs to be used in a beneficial reuse scenario. MSD recently considered a vertical expansion project for the Prospect Hill Landfill (see Project 11094 in Section 5.2), but that project was put on hold. The planning team estimated the available remaining volume of the existing Prospect Hill Landfill. With the final cover volume taken into consideration, the existing landfill configuration has Page 14 of 24 approximately thirty-five percent (35%) of available capacity remaining, which is around 710,000 cubic yards. This estimate is based on a 2014 calculation using AutoCAD Civil 3D 2010, an estimated final cover volume of 30,000 cubic yards, and ash disposal data from 2015 through 2017. Table 3-1 shows the historic incinerator ash disposal at Prospect Hill from 2010 through 2017, for which the average annual ash disposal was around 49,500 cubic yards per year. MSD is in the process of relocating the entrance road to Prospect Hill Landfill in order to improve the site usage. It is estimated that, with this site change, the landfill will be able to meet operational needs for about 15 years.1 Table 3-1. Historic Ash Disposal at Prospect Hill Landfill Year Bissell Ash Hauled (cy) Lemay Ash Hauled (cy) Total Ash Hauled (cy) 2010 0 43,038 43,038 2011 44,834 57,151 101,985 2012 0 0 0 2013 0 39,971 39,971 2014 0 0 0 2015 72,472 46,830 119,302 2016 0 19,953 19,953 2017 71,531 0 71,531 Average (cy/yr) 23,605 25,868 49,473 3.2.5 Sludge Land Application MSD’s treatment facilities are located in an urban area and generate a significant mass of sludge (approximately 75,000 dtpy). Land application of all of this material as “Class B” biosolids would be logistically difficult and probably would not be cost effective relative to other options. Converting this sludge to a “Class A” material (i.e., residential compost) might be an option, but the dynamic nature of MSD’s raw sludge quality at Bissell Point WWTF in particular could cause anaerobic digestion process problems. User demand for the material is cyclical and uncertain. Notwithstanding this, the regulatory burden to land application would be especially significant for facilities like Lemay and Bissell Point WWTFs, which generate the majority of sludge. These plants receive discharges from St. Louis industrial discharges and as combined treatment facilities, legacy metals in soils within the St. Louis area could also affect metals levels in sludge. Metals and other pollutants in land applied biosolids are highly regulated under 40 CFR 503. Future land application of sludge would require a new look at the local limits that MSD requires of industrial discharges, the compliance mechanism being industrial pretreatment permits. The likely outcome of this assessment and revised permits would be that industries that discharge metals and other regulated pollutants would need to install additional pretreatment equipment to comply with these new local limits. As a practical enforcement matter, when a problem with pollutant levels in MSD’s sludge occurs, it may be practically impossible to track down and/or remediate the source of the problem given the number of industries and difficulties distinguishing industrial versus domestic sources. 3.2.6 Nutrient Control Solids handling can significantly impact nutrient2 controls within wastewater treatment facilities. It is likely that nutrient controls will be required as (1) part of a broader far-field approach to managing nutrients to reduce the Gulf of Mexico dead zone or (2) part of new technology based effluent limits implemented as an amendment to existing secondary treatment regulations. MSD has studied options and developed alternatives for nutrient controls for each treatment facility. Based on the 1 MSD is in the process of updating this estimate per an updated survey of the landfill. 2 Total nitrogen and/or total phosphorous Page 15 of 24 “Comprehensive Ammonia and Nutrient Removal Master Plan”, potential capital costs vary based on the specifics of requirements, and total capital costs are likely to range from $200 to $500 million. MSD’s WWTF operating permits were renewed on January 1, 2018, and none of these permits require nutrient control. MDNR is unlikely to reopen or reissue MSD’s operating permits before 2023. Therefore nutrient controls are at least five (5) years away and more likely a decade away given the current pace and priorities for regulations. Even so, MSD should plan any solids handling improvements keeping in mind that these improvements need to accommodate future nutrient controls. MSD’s solids handling plans need to consider ways to prevent the nutrient load into the headworks of the Lemay wastewater plant from increasing, which should allow TN and TP levels in effluent to be less than 10 mg/L and 1 mg/L, respectively, on an annual basis using existing and/or optimized existing equipment. Page 16 of 24 3.3 Cost Evaluation The costs associated with the four sludge handling alternatives are illustrated as Options #1 through #4 in Figure 3-1. To develop these costs, the planning team updated the SMP costs to reflect changes to the original alternatives and an increase due to inflation. The team also used the “County Solids Pre-Design Report” (see Section 2.3.3) to develop costs for anaerobic digesters. Figure 3-1. Future Long-Term Solids Disposal Options #1, #2, #3, & #4 The cost estimating was performed on a conceptual level with less than 5% engineering. Thus, each option is viewed to be of comparative cost due to the level of uncertainty in the estimates. A detailed spreadsheet that describes the costs for each Option can be found in Appendix J, but the following sections provide a brief summary of the conceptual costs for Options #1 through #4. As discussed in later sections, advanced emission controls (AEC) will likely be required for fluidized bed incinerators. Page 17 of 24 Additionally, the planning team anticipates that steam generation will be needed for plant HVAC needs. Therefore, these costs should be added to each option. 3.3.1 Option #1 – Master Regional As described in Section 2.2.1, Option #1 includes regional fluidized bed incineration at the Bissell Point WWTF. The total capital cost for this option, in millions (MM) 2017 dollars are as follows: Bissell Incinerators and Centrifuges $ 264.4 MM Grand Glaize Sludge Forcemain $ 12.4 MM Lower Meramec Sludge Forcemain $ 23.4 MM Lemay Sludge Forcemain $ 62.1 MM Total $ 362.3 MM Add Steam $ 26.4 MM AEC $ 48.5 MM Total $ 437.2 MM No operational costs are included above. Additional dewatering capacity may be needed for Lemay WWTF sludge. The original concept in the SMP was that Lemay WWTF cake would be hauled to Bissell Point WWTF, and MSD is now planning to send Lemay WWTF sludge to Bissell Point WWTF via a sludge forcemain. 3.3.2 Option #2 – Regional Lower Meramec WWTF Digesters As described in Section 2.2.2, Option #2 includes fluidized bed incineration at the Bissell Point WWTF and digestion facilities at Lower Meramec WWTF. The total capital cost for these facilities, in 2017 dollars, is as follows3: Bissell Incinerators and Centrifuges $ 192.1 MM Adjustment for Additional Capacity at Bissell $ 77.6 MM Grand Glaize Sludge Forcemain $ 12.4 MM Lemay Sludge Forcemain $ 62.1 MM Regionalized Lower Meramec Anaerobic Digesters (Appendix B) $ 34.2 MM Total $ 378.4 MM Add Steam $ 24.0 MM Add AEC $ 48.1 MM Total $ 450.5 MM The Bissell Point WWTF incinerator costs are based on the SMP costs for 70 dtpd and 120 dtpd incinerators. It is possible that a different incinerator capacity configuration could be used for this option (e.g., three 100 dtpd incinerators). Thus, costs for alternative incinerator sizing should be obtained to properly account for this option. 3.3.3 Option #3 – Sub-Regional Lower Meramec & Grand Glaize WWTFs Digesters As described in Section 2.2.2, Option #3 includes fluidized bed incineration at the Bissell Point WWTF and digestion facilities at Lower Meramec WWTF and Grand Glaize WWTF. The total capital cost for these facilities, in 2017 dollars, is as follows4: Bissell Incinerators and Centrifuges $ 192.1 MM Adjustment for Additional Capacity at Bissell (Appendix A, Table-8) $ 77.6 MM Lemay Sludge Forcemain $ 62.1 MM Local Grand Glaize Anaerobic Digesters (Appendix B) $ 22.3 MM 3 Bissell incinerator costs were developed based on Table 1-34 in TM-1, which is included in Appendix D. An inflation factor of 1.28 was used to convert 2010 dollars to 2017 dollars. 4 Bissell incinerator costs were developed based on TM-1, Table 1-34 and Table 2-34, which are included in Appendix D and Appendix E, respectively. A factor of 1.28 was used to convert 2010 dollars to 2017 dollars. Page 18 of 24 Local Lower Meramec Anaerobic Digesters (Appendix B) $ 28.6 MM Total $ 382.7 MM Add Steam $ 24.0 MM Add AEC $ 48.1 MM Total $ 454.8 MM The Bissell Point WWTF incinerator costs are based on the SMP costs for 70 dtpd and 120 dtpd incinerators. It is possible that a different incinerator capacity configuration could be used for this option (e.g., three 100 dtpd incinerators). Thus, costs for alternative incinerator sizing should be obtained to properly account for this option. 3.3.4 Option #4 – Sub-Regional Bissell Point & Lemay WWTFs Incineration As described in Section 2.2.4, Option #4 includes fluidized bed incineration at both Bissell Point and Lemay WWTFs. No digestion facilities would be constructed. The total capital cost for these facilities, in 2017 dollars, is as follows. Costs are included to raise the Lemay WWTF incinerator site above the floodplain. Bissell Point Incinerators and Centrifuges $ 192.1 MM Lemay Incinerators and Centrifuges $ 151.1 MM Lemay Site Work $ 4.0 MM Grand Glaize Sludge Forcemain $ 12.4 MM Lower Meramec Sludge Forcemain $ 23.4 MM Total $ 383.0 MM Add Steam – Bissell Point $ 17.2 MM Add AEC – Bissell Point $ 33.0 MM Add Steam – Lemay $ 13.9 MM Add AEC – Lemay $ 30.2 MM Total $ 477.3 MM 3.4 Selected Alternative Major factors and considerations were discussed among the planning team and management, and the consensus was to move forward with Option #4 as the preferred approach. The planning team believes that Option #4 presents the lowest risk to unexpected increases to the capital cost estimate or operation costs. Additionally, there is good potential for lowering costs with a design-build approach. Permitting for Option #4 is straight-forward because existing facilities will be upgraded to higher performance. Option #4 would not require the Lemay to Bissell Point forcemain, which presents issues due to construction through the City. Additionally, with new FBIs located at both Bissell Point and Lemay WWTFs, the opportunity exists for similar facility operations and equipment for training, maintenance, inventory, and other benefits. With incineration at two locations, there is potential to coordinate combined capacity of the facilities for emergency backup versus otherwise maintaining redundant, excess capacity at a standalone facility. With the dual incineration facilities, sludge hauling could occur during instances such as the FBI annual overhauls/maintenance activities. However, a coordination plan between facilities would be required to maintain capacity during outages. The planning team did not select Option #1 because of permitting concerns and issues with the forcemain from Lemay WWTF to Bissell Point WWTF. Options #2 and #3 were not selected because these options may not be cost effective and may be a target of neighborhood objection due to odors from new digesters at Lower Meramec WWTF. Additionally, both Options #2 and #3 would require entirely new air permits. The Lemay to Bissell Point forcemain through the City would also cause issues for Options #2 and #3. Page 19 of 24 4. Option #4 Planning Considerations After deciding to move forward with Option #4, the planning team considered additional details regarding the proposed FBIs at Bissell Point and Lemay WWTF. For budgeting purposes, the planning team wanted to verify the FBI sizing and investigate whether advanced emission controls would be needed. 4.1 FBI Sizing Option #4 proposes the use of two 120 dtpd FBIs at Bissell Point WWTF and two 70 dtpd FBIs at Lemay WWTF. The planning team initially used the SMP sludge data to size these incinerators. The team then compared the SMP data to operational data from the MSD’s HachWIMS (WIMS) database and also reviewed the sludge production data from the Comprehensive Ammonia and Nutrient Removal Master Plan (see Section 2.3.2). A summary of this comparison is shown in Table 4-1. Additional information on the sludge data comparison and FBI sizing can be found in Appendix A. Table 4-1. FBI Sizing: SMP vs. Other MSD Data Data Source Bissell Point Lemay Existing Incinerator Capacity • 240 dtpd total capacity • 4 MHIs x 60 dtpd each • 180 dtpd total capacity • 3 MHIs x 60 dtpd each SMP FBI Design • 2 x 120 dtpd FBIs = 240 dtpd • 1 designed to handle annual average • All incinerators needed to handle maximum month • 2 x 70 dtpd FBIs = 140 dtpd • 1 designed to handle annual average • All incinerators needed to handle maximum month SMP Sludge Data • Max. Month = 125.7 dtpd • Annual Avr. = 89.1 dtpd • Modeled solids production assuming biological nutrient removal • Does not include impacts due to inflow from Mississippi River flood gates Lemay + Lower Meramec WS • Max. Month = 147.2 dtpd • Annual Avr. = 90.2 dtpd • Does not include high rate treatment impacts Lemay Only • Max. Month = 94.0 dtpd • Annual Avr. = 51.1 dtpd • Does not include high rate treatment impacts WIMS Sludge Data • Max. Month = 249.3 dtpd • Annual Avr. = 105.6 dtpd • Does not include biological nutrient removal impacts • Sludge production may decrease w/ repair of flood gates to reduce river inflow Lemay + Lower Meramec WS • Max. Month = 97.9 dtpd • Annual Avr. = 66.3 dtpd • Does not include high rate treatment impacts Lemay Only • Max. Month = 78.3 dtpd • Annual Avr. = 51.1 dtpd • Does not include high rate treatment impacts Page 20 of 24 Data Source Bissell Point Lemay Total Sludge Production w/ Nutrient Removal • Modeled Sludge Production Based on Max. Month Wastewater Flow = 130 to 190 dtpd (post-2030) • Varies depending on selected nutrient removal processes Lemay + Lower Meramec WS • Modeled Sludge Production Based on Max. Month Wastewater Flow = 70 to 90 dtpd (post-2030) • Varies depending on selected nutrient removal processes The planning team believes that the two 120 dtpd FBIs at Bissell Point WWTF and the two 70 dtpd FBIs at Lemay WWTF will provide sufficient capacity. Although, the design engineer should consider different sizing alternatives or storage that would best meet the normal and peak operating scenarios. All alternative configurations should be of comparable cost to the Option #4 cost shown in Section 3.3.4. The design engineer should also consider whether additional storage or incinerator capacity will be needed with increased sludge production from nutrient removal projects in the post-2030 timeframe and account for likely future capacity expansion. Additionally, the design engineer should consider whether the future high rate clarification facility at Lemay (see Section 2.3.4) will impact the FBI capacity needs at the Lemay WWTF. 4.2 Advanced Emissions Controls The planning team recognized that further consideration is required to determine the need for additional emissions controls for the new FBIs at Bissell Point and Lemay WWTFs to meet the 40 CFR Part 60, Subpart LLLL limits. These limits are the minimum design requirements for new FBIs and are listed in Table 4-2. Table 4-2. 40 CFR Part 60, Subpart LLLL Emission Limits for New Fluidized Bed Incinerators Pollutant Limit Particulate matter 9.6 mg/m3 Hydrogen chloride 0.24 ppm Carbon monoxide 27 ppm Dioxins/furans (total mass basis); or Dioxins/furans (toxic equivalency basis) 0.013 ng/m3 (total mass basis) or 0.0044 ng/m3 (toxic equivalency basis) Mercury 0.0010 mg/m3 Oxides of nitrogen 30 ppm Sulfur dioxide 5.3 ppm Cadmium 0.0011 mg/m3 Lead 0.00062 mg/m3 Fugitive emissions from ash handling Visible emissions of combustion ash for no more than 5 percent of the hourly observation period All volumes dry, standard conditions The planning team specifically looked at whether advanced emissions controls would be needed for mercury. The Subpart LLLL mercury limit is based on emissions achieved by existing FBIs at two treatment plants that presently use activated carbon for mercury control. The planning team evaluated the mass loading of mercury at Bissell Point and Lemay WWTFs to estimate whether the plants could meet the mercury limit without advanced controls. The team found the actual industrial mercury loading to presently be 0.008 lb/day at Bissell Point WWTF and 0.002 lb/day at Lemay WWTF and the residential loading to be below the 0.0003 mg/L detection limit at both facilities. Despite this relatively low influent mercury loading, the mass balance indicated that Bissell Point and Lemay FBIs may have Page 21 of 24 issues meeting the mercury limit with only the use of a wet scrubber system. Furthermore, the planning team estimated mercury emissions for new FBIs at Bissell Point WWTF and Lemay WWTF were estimated using the U.S. EPA AP-42 mercury emission factor for FBIs with non-carbon controls. The estimated mercury emissions were about 2 to 4 times higher than the Subpart LLLL limit. The design engineer should evaluate this information and determine the appropriate pollution control system. A summary of the mercury loading analysis and a link to the computations may be found in Appendix H. Additionally, it is possible that Bissell Point WWTF and Lemay WWTF will need urea or ammonia addition for compliance with the Subpart LLLL nitrogen oxides limit. Also, Bissell Point WWTF has experienced issues with cadmium emissions during recent performance tests. The selected advanced emission controls must have a design engineer or manufacturer guarantee for the equipment performance for all of the Subpart LLLL parameters. 5. Related CIRP Projects With the selection of Option #4, the planning team identified MSD Project 12565 for the construction of FBIs at the Bissell and Lemay WWTFs. At present, the budgeted construction fiscal year for Project 12565 is 2023. The team identified other capital projects that will or may impact Project 12565, and these projects are detailed below. 5.1 Nutrient Removal Facilities MSD is finalizing the “Comprehensive Ammonia and Nutrient Removal Master Plan” (Project 12070) to inform and guide the District’s ammonia and nutrient removal strategy at wastewater treatment facilities over the next 15 years. This study provides data on the future increased sludge generation for the nutrient removal alternatives. Refer to the plan for details on the associated capital projects at each plant. The future improvements installed at Coldwater, Grand Glaize, and Lower Meramec WWTFs need to consider the impacts of moving sludge via forcemains between facilities and the selection of an appropriate technology that will not cause unintended consequences or costs on other downstream facilities. One recommendation was to use chemical phosphorous removal rather than biological removal to avoid additional, inordinate expenses related to removal of the same nutrients at two different plants. Chemical treatment at the up-gradient plant would allow for economical physical removal at the downstream plant in primary treatment without impacting significantly the biological nutrient removal at the plant. 5.2 Prospect Hill Landfill The Prospect Hill Landfill Vertical Expansion (11094) project includes the construction of improvements to the Prospect Hill Landfill to enable full utilization of the permitted land capacity for incinerator ash disposal. The conceptual construction cost is $1,000,000, but this project was put on hold due to extensive permitting requirements. See Section 3.2.4 for more details. 5.3 Lower Meramec WWTF to Fenton WWTF Tunnel MSD is constructing a deep tunnel in phases to convey wastewater flows from the Lower Meramec Watershed to Lower Meramec WWTF. The Fenton interim treatment plant will be decommissioned after the deep tunnel is constructed. The first phase of the tunnel, the “Lower Meramec River System Improvements - Baumgartner Tunnel” (96055B) project, was completed in 2007, which eliminated the Baumgartner Treatment Plant. This initial segment, the Lower Meramec Tunnel, begins at the Lower Meramec WWTF and extends to an access shaft on Baumgartner Road, east of Lemay Ferry Road. Page 22 of 24 The second phase of the tunnel project is the “Lower Meramec River System Improvements – Baumgartner to Fenton WWTF Tunnel” (11746). This project includes the construction of 36,000 feet of 96-inch diameter deep tunnel to convey wastewater from the Fenton WWTF to the Baumgartner Tunnel. This project will enable treatment of flows at the Lower Meramec WWTF so that the Fenton WWTF can be eliminated. The conceptual construction cost is $209,000,000 and the budgeted construction date is FY2021 to FY2024. 5.4 Sludge Forcemain Lower Meramec WWTF to Lemay WWTF The “Sludge Transfer Forcemain – Lower Meramec WWTF to Lemay WWTF” (13076) project includes the construction of 53,750 feet of 6-inch forcemain and 3 pump stations to convey sludge from Lower Meramec WWTP to Lemay WWTP. Highly diluted sludge will enter the Lower Meramec WWTF Pump Station via the Lower Meramec Tunnel, where it will be lifted to the primary clarification tanks. Primary Sludge and WAS from the secondary clarifiers (assuming the trickling filters will be replaced with activated sludge) will be co-thickened in the gravity thickeners, then pumped to Lemay WWTF through the new forcemain along with the sludge from the Lower Meramec WWTF. The conceptual construction cost is $23,300,000, and the budgeted construction date is FY2025 to FY2026. Additional details on the forcemain can be found in Appendix I. 5.5 Sludge Forcemain Grand Glaize to Fenton The “Sludge Transfer Forcemain – Grand Glaize WWTF to Fenton” (13077) includes the construction of 23,400 feet of 6-inch forcemain and one pump station. The forcemain will convey sludge from Grand Glaize WWTF to the Riverside/Yarnell gravity trunk sewer. Once the sludge enters the trunk sewer, the sludge will flow to the future Fenton Dropshaft, where it will enter the Lower Meramec Tunnel along with flow that presently is treated by Fenton WWTF. This flow will go the Lower Meramec WWTF. The conceptual construction cost is $10,100,000, and the budgeted construction date is FY2025. Additional details on the forcemain can be found in Appendix I. 5.6 Fenton Wastewater Treatment Facility Elimination The “Fenton Wastewater Treatment Facility Elimination” (12170) project includes the elimination of the Fenton WWTF. The facility will be decommissioned and the watershed outfall sewers will be connected to the Fenton-Baumgartner Tunnel so that the flows will be conveyed to the Lower Meramec WWTF. The conceptual construction cost is $7,100,000, and the budgeted construction date is FY2024. 5.7 HVAC Upgrades at Lemay and Bissell Point WWTFs This project is related to the installation of fluidized bed incinerators at Lemay and Bissell Point WWTFs and should be considered during the design of the FBI project. The project will include an evaluation of the existing condition of the HVAC systems and investigate steam generation requirement from FBIs exhaust heat recovery boilers. The project cost and budgeted construction fiscal year have not been identified for this project. 5.8 Bissell Point WWTF Redundant Sludge The “Bissell Point WWTF Redundant Sludge Acceptance System” (12828) project includes the construction of additional sludge hoppers and conveyors at the Bissell Point WWTF. This project was identified because the existing sludge acceptance system at Bissell Point WWTF is nearing end of life. This project is being cancelled and incorporated into the fluidized bed incinerator project. 5.9 Lower Meramec WWTF PH II The “Lower Meramec WWTF Expansion Phase II” (12255) project includes the expansion of the Lower Page 23 of 24 Meramec WWTF to increase capacity for additional flow from the Lower Meramec Tunnel and Fenton WWTF. It will upgrade the facility to accommodate potential nutrient removal requirements. The conceptual construction cost is $100,000,000, and the budgeted construction date is FY2022 to FY2024. 5.10 Coldwater WWTF Redundant Sludge Forcemain The Coldwater Creek WWTF Redundant Sludge Forcemain (12550) project includes the construction of 17,500 feet of an 8-inch parallel sludge forcemain. Thickened sludge from the Coldwater Creek WWTF is presently pumped to the Bissell Point collection system via a ductile iron forcemain. This pipe is near the end of its useful life due to internal corrosion. Thus, the existing forcemain operation will need to be protected with a parallel forcemain, allowing for the possibility of rehabilitation. The conceptual construction cost is $7,000,000, and the budgeted construction date is FY2022. 5.11 Lemay Facility Upgrades (Phase 2) The “LMRDP CSO Storage Tunnel (Broadway to RDP Tubes)” (11820) project includes the construction of a deep storage tunnel system in the Lemay Watershed. The tunnel will be 30-foot in diameter, 9 miles long, and 200 to 250 feet deep and will approximately follow the River Des Peres alignment. This project will include several connection tunnels, access shafts, and intake structures. The conceptual construction cost is $721,500,000. The “LMRDP Tunnel Dewatering Pump Station” (11816) project will include the construction of a pump station to pump stored combined sewage from the deep tunnel to the Lemay WWTF. The conceptual construction cost is $100,500,000. The LMRDP project construction dates are being moved per the CD Material Modification, to be completed by 2037. 6. Conclusions and Recommendations The planning team considered four sludge handling alternatives, which are described in Section 2.2. For all the factors and considerations above, the District concluded that the Option #4 is the recommended option. Option #4 includes the following sludge handling components at MSD’s WWTFs: 6.1 Bissell Point and Lemay WWTFs New fluidized bed incinerators, sludge dewatering, and sludge handling equipment will be installed at Bissell Point and Lemay WWTFs as described herein. The planned facilities are recommended to have both sludge load-out and receiving capabilities in order to provide emergency backup receiving and off- loading capabilities if normal sludge handling at a facility becomes disrupted for any reason. The facilities should be designed to allow for economic disposal of waste ash, and preferably have a dry ash handling system to allow loadout to maximize opportunities for beneficial reuse. Waste heat recovery should be used for energy efficiency and meeting plant needs for steam. Expansion of steam generation and sale, and/or energy generation may be acceptable in final design if the project can be proven to have a good payback term. At present, these expanded options do not appear to be economically justified. 6.2 Coldwater WWTF The existing solids handling scheme will be maintained. The solids handling includes a pump station and forcemain into the Bissell Point Service Area, and solids being conveyed through the collection system to the Bissell Point WWTF. The existing forcemain was installed in 1990, and is approaching its end of life. The recommendation is to install a redundant forcemain in the same corridor. (See the description of Project 11820 in Section 5.10.) The receiving collection system was rehabilitated and lined to counteract hydrogen sulfide deterioration. Page 24 of 24 6.3 Missouri River WWTF The existing solids handling scheme will be maintained, which includes relatively new digestion facilities. Digested sludge disposal may include landfilling, land application, or composting. 6.4 Grand Glaize WWTF The recommendation is to utilize the existing Chrysler plant to Grand Glaize forcemain corridor to construct new sludge pump stations and a forcemain to convey sludge from the WWTF into the Fenton Service Area. The flow will be introduced into the Riverside-Yarnell trunk sewer at a desirable location, likely just south of Highway 44. (See Project 13077 in Section 5.5.) Additional details on the forcemain can be found in Appendix I. The consideration of receiving sewer rehabilitation will be required to address hydrogen sulfide corrosion and odor control. 6.5 Fenton WWTF The facility will be decommissioned and replaced with a drop shaft to the Lower Meramec Tunnel Phase 2, Baumgartner to Fenton. (See Project 12170 in Section 5.6.) 6.6 Lower Meramec WWTF The recommendation is to convey sludge from Lower Meramec WWTF to the Lemay WWTF via pump stations and a forcemain. (See Project 13076 in Section 5.4 and Project 11746 in Section 5.3.) The forcemain will convey the sludge to Lemay plant sludge handling facilities directly, thereby avoiding impacts to Lemay’s nutrient removal strategy, which is anticipated to be minimal at the present time. Additional details on the forcemain can be found in Appendix I. Appendix A – Incineration Facility Alternatives 1 Incineration Facility Alternatives The information in this section was derived from the Technical Memos (TM) 1, 2, 6, & 9 in the Comprehensive Solids Handling Master Plan Phase II report. Three of the options presented in the Solids Handling Master Plan are called out and detailed herein as the basis for further consideration. Because there was a significant amount of engineering work completed for the development of the TMs, the information is mostly summarized intact from the report without alteration. Links to the TMs may be found in Appendices C through F. Regional Solids Processing Facility – Bissell Point (SMP TM-6 R-1) Location - The new Regional Facility will be located in the existing Bissell Point WWTF and is proposed to be sited east of the Administration Building and existing incinerators, west of the ash lagoons, as shown in Figure 1. Figure 1. Regional Solids Handling Facility Site Plan 2 The Regional Facility will receive dewatered solids from Lower Meramec (including Fenton and Grand Glaize), Missouri River, Lemay and Bissell Point WWTFs (including Coldwater solids). The dewatered solids from Lemay and Lower Meramec will be transported to the site via hauling or new sludge force mains, while solids generated at the Bissell Point Treatment Facility will be handled in a new Dewatering Building. Figure 2 illustrates the overall process flow diagram for the Regional Facility less the dewatering of Bissell Point sludge. Figure 2. Regional Solids Process Flow Diagram Regional Solids Quantities - The future solids quantities used for this evaluation were carried forward from Phase I – TM-2: Facility Summaries and Solids Projections for all WWTFs with exception of the Bissell Point and Coldwater WWTFs. Solids quantities for Bissell Point (including Coldwater) were estimated using wastewater treatment process models due to the elimination of anaerobic digestion at Coldwater WWTF in 2008. Solids quantities for all facilities are presented in Table 1 below based on Table 6-1 of Phase II TM-6. Table 1. Projected Regional Solids Quantities Solids Source VS % of TS1 VS (dtpd)1 TS (dtpd)1 Bissell Point WWTF 58.0 58.2 51.9 73.0 89.1 125.7 Lemay WWTF 45.5 50.5 25.8 42.8 51.1 94.0 Missouri River WWTF 80.1 80.2 38.2 46.5 47.7 58.0 Lower Meramec WWTF 74.9 75.1 29.4 39.9 39.2 53.2 Total Solids 61.0 64.0 145.3 202.2 227.0 331.0 1Annual Average|Maximum Month Dewatered solids received at the Regional Facility will vary in total solids (TS) concentration and volatile organic composition depending on each treatment facility’s processes and seasonal variation. 3 A cake solids concentration of 25 percent TS was used for equipment sizing throughout this evaluation to ensure that sufficient operating and storage volume is provided during low percent TS conditions from the various plants. The volatile solids (VS) fractions in the Bissell Point WWTF and Lemay WWTF solids are relatively low. This is attributed to increased concentrations of inorganic material accumulating from inflow and/or infiltration during high flow events. The maximum month quantities were used as the basis for equipment sizing at the Regional Facility. The annual average quantities were used as the basis for determining the operations and maintenance (O&M) costs. The receiving cake storage is sized to provide three days storage at annual average conditions. Solids Processing Evaluation - Implementation of a Regional Solids Processing Facility will require completely new equipment to obtain the capacity of 360 dry tons per day (dtpd). The solids management processes evaluation included the following facilities:  cake receiving and handling  dewatered cake equalization bins  fluidized bed incinerators (FBIs) and blowers  air pollution control (wet scrubber)  advanced air pollution control (fine particulate and mercury removal with dry ash handling)  heat recovery exchangers and boiler  odor control Refer to SMP II TM-6, which is included in Appendix C of this report for detailed process flow schematics. Technologies for Solids Processing Evaluation - The solids processing technologies selected for the Regional Facility are discussed in the following sections. a) Solids Receiving - Dewatered cake will be hauled from the Lemay, Missouri River and Lower Meramec WWTFs using end-dump trucks or trailers. Hauled cake will be discharged into the solids live-bottom bin with conveyors, which will transfer the cake to the equalization bins. Each equalization bin will use a sliding frame type live bottom to prevent cake bridging, which will discharge to a collection screw conveyor. The collection screw will feed one of two piston type cake pumps (1 duty, 1 standby). Refer back to Figure 2 for an illustration of the receiving process. No dewatering will be provided at the Solids Receiving Facility other than that for Bissell Point WWTF solids. Preliminary equipment design information for the cake receiving facility and cake feed pumps is as follows: Solids receiving pit L x W x D (ft) 130 x 50 x 15 Clamshell capacity (cy) 10 Cylindrical equalization bins (#) 3 Equalization bins H x D (ft) 20 x 15 Cake pumps (#) 6 Pump capacity (dtph ea.) 5 b) Incinerator Systems - Three fluidized bed incinerator (FBI) trains of 120 dtpd capacity each will be installed in the new Solids Processing Building as part of the Regional Facility. Supplemental firing with natural gas will be provided as needed to maintain combustion temperature. Refer back to Figure 2 for an illustration of the incineration process. The incinerators are sized such that two of the three incinerator trains must be operated to process annual average solids quantities. All three incinerators must be operated to support maximum month solids quantities. No spare or standby capacity is provided at maximum month conditions. 4 Preliminary equipment design criteria for the FBI vessels are as follows: Number of FBI trains 3 Throughput capacity (dtpd ea) 120 Incinerator vessel type Insulated fire brick lined w/refractory brick Windbox Arch, hot air Size, D x H (ft) 34 x 45 Minimum natural gas (psig) 10 Discharge temperature (°F) 1,500 to 1,650 max c) Heat Recovery - Primary and secondary heat exchangers (HEX) will recover waste heat from the exhaust gases. The primary HEX will transfer heat to the fluidizing air input. This “hot windbox” design will reduce the amount of auxiliary fuel required for combustion and, in some cases, may allow autogenous (without additional fuel) combustion. A secondary HEX will transfer heat to the scrubber outlet gas, which will help suppress visible plumes from the exhaust stack. The secondary HEX may also be used to pre-heat exhaust prior to emission control equipment. Preliminary design criteria for the HEX’s are as follows: Number of primary HEX 3 Type Shell and tube Configuration Vertical, counterflow Exhaust gas in/out (°F) 1,650/1,200 Fluidizing air in/out (°F) 60/1,030 Size, D x H (ft) 12 x 30 Air pressure (psig) 10 Number of secondary HEX 3 Type Shell and tube Configuration Vertical, counterflow Exhaust gas in/out (°F) 1,200/1,050 Scrubber outlet gas in/out (°F) 100/300 Size, D x H (ft) 12 x 30 Air pressure (psig) 10 d) Air Pollution Control Equipment - Exhaust gases leaving the primary HEX’s will be directed to the Air Pollution Control Equipment that include quench sprays and wet scrubbers. The scrubber will be a vertical upflow unit with impingement trays used for cooling and saturating the gas, followed by a multiple fixed venturi section with water injection and mist eliminators with sprays. Secondary effluent water will be used for the impingement trays and venturis. Potable water will be used for the mist eliminator sprays to prevent clogging. Booster pumps will be supplied with the scrubbers for venturi and high pressure spray water injection. Preliminary equipment criteria for the wet scrubbers are as follows: Number of wet scrubbers 3 Type Combined impingement tray and multiple fixed venturis Configuration Vertical, upflow Size, D x H (ft) 14 x 30 Quench spray flow (gpm) 150 Undertray spray flow (gpm) 100 Impingement tray spray flow (gpm) 1,650 Venturi section flow (gpm) 200 Mist eliminator flow (gpm) 15 5 Each incinerator will have a dedicated blower to supply fluidizing air drawn from outside the Solids Processing Building. The air will be preheated in the primary heat exchanger before entering the FBI windbox. Fluidizing air serves three purposes: to suspend the solids in the incinerator bed; to provide combustion air; and, to carry off combustion products. The blowers will be multiple-stage, centrifugal compressors with direct drive 700 hp motors. The required flow rate is 13,000 scfm at 8 psig for each train. Further specification tables for various sub-systems are provided in TM-6 as follows: Table 6-7 Ash Slurry Tanks and Pumps (60% VS basis) Table 6-9 Fuel Oil Storage Tank and Pumps Table 6-10 Sand System Tanks and Transporters e) Waste Heat Boilers - Waste heat from the exhaust gases will be used to generate steam in the Waste Heat Boilers. The steam will be used for heating/cooling or to generate electricity. The boilers are placed downstream of the primary HEX as shown in Figure 3 below. Figure 3. FBIs with Optional Steam and Power Generation Preliminary equipment design criteria for the waste heat boilers producing high quality steam are as follows: Number of boilers 3 Type Water Tube Flue gas inlet temperature (°F) 1,200 Flue gas outlet temperature (°F) 500 Flue gas flow rate (pph ea) 115,800 Steam pressure (psia) 400 Steam temperature (°F) 600 (superheated) Steam flow rate (pph ea) 20,800 6 Specifications for various sub-systems are provided in TM-6 as follows: Table 6-12 Packaged Water Treatment System and Pumps Table 6-14 Steam Turbine Generator (2.9 MW) Table 6-15 Steam Condenser and Condensate Pumps Table 6-16 Cooling Water Heat Exchanger Table 6-17 Condensate Handling System f) Advanced Air Pollution Control System - It is anticipated that Advanced Air Pollution Controls will be required for removal of mercury from incinerator exhaust gases. Mercury differs from other hazardous metals in the incineration process because it is volatile (high vapor pressure). Metals in the incinerator feed solids typically are removed from the process entrained in the ash or through the wet scrubber as solid oxides, chlorides, hydroxides, etc. While some mercury becomes entrained in the ash or is collected in the wet scrubber, the remainder is volatilized as elemental mercury (Hg0) in the incinerator. As the gaseous elemental mercury is cooled through the remaining processes, it can react with other components of the flue gas to form oxidized gaseous mercury (Hg2+) combining with halogens (chlorine, fluorine, and bromine) or oxides of sulfur, such as sulfur dioxide (SO2) and sulfur trioxide (SO3) or nitrogen, such as nitrogen dioxide (NO2). Little mercury is typically retained in the ash. A fraction of the oxidized mercury (Hg2+) is soluble in water and is captured in the wet scrubbing process. The elemental mercury species, which has low solubility in water and is emitted from the stack, must be oxidized and removed through another stage of scrubbing. Advanced Air Pollution Controls may also be needed for other pollutants such as cadmium and nitrogen oxides. The exhaust gases from the secondary heat exchanger will be directed to the advanced air pollution control system. Air pollution control equipment for mercury removal includes an exhaust gas conditioning tower, carbon injection tower, carbon storage, fabric filter (followed by previously described wet scrubber), dry ash system, and an induced draft (ID) fan. Figure 4 shows the main mercury scrubbing process using powdered carbon injection and a fabric filter.1 Figure 4. Advanced Air Pollution Control System with Mercury Scrubbing 1 The design engineer should also consider the use of a wet ash system (e.g., a packed carbon tower with a wet ash system). MSD does not prefer baghouses. 7 Mercury removal may also be accomplished by fixed bed carbon adsorbers. Comparison of the different mercury scrubbing options was not included for this evaluation, but it is recommended prior to final system selection. Fixed-bed carbons adsorbers use granulated activated carbon, which avoids the potential explosion hazard of powdered carbon dust. Typical carbon replacement frequency is about 10 years. Descriptions of the various advanced air pollution control equipment required for a carbon injection system are included below referencing the detailed tables from TM-6. Table 6-19 Gas Conditioning Tower Table 6-20 Carbon Injection and Storage Table 6-21 Fabric Filter System Table 6-22 Dry Ash System Table 6-23 Induced Draft Fans Regional Layout Plans – The layout of the new Solids Processing Building is shown as Figure 5 on the next page. This layout is for the ground floor of the four level building and shows the footprint of major components. Other level layouts may be found in TM-6 linked in Appendix C. The footprint of the main building with incinerators, scrubbers, and sludge load-in is 315 ft by 160 ft. Peripheral systems including the centrifuges require an additional 90 ft by 315 ft. Regional Cost Summary - Table 2 presents the Engineer’s Opinion of Costs for construction, annual operation and maintenance, annual savings with biosolids use, and life cycle costs from Table 6-25 in TM-6. These costs and benefits were developed and presented in the detailed SMP Ph II TM-9 “Opinions of Costs for Alternatives” found in Appendix F. All costs and savings are in 2010 dollars for a 20-year service life. Alternatives are incremental cost and benefits applied to the base case of fluidized bed incinerators (FBI) with dewatering centrifuges (+ CFG). Table 2. Costs Summary of Regional Facility (in $1,000,000) Alternative FBI + CFG Add Steam Add Power Add AEC Capital $ 206.6 $ 20.6 $ 41.2 $ 37.9 Salvage Value ($ 2.1) ($ 0.4) ($ 0.3) ($ 0.6) O & M $ 170.1 $ 6.3 $ 10.8 $ 0.4 Revenue ($ 0.0) ($ 23.7) ($ 14.2) $ 0.0 Total Present Worth Costs $ 374.6 $ 2.8 $ 37.5 $ 37.7 To obtain costs in 2017 dollars, a factor of 1.28 will apply. For example, the capital cost for the base case with steam and AEC would be $ 265.1 million in Year 2010 dollars and $339.3 million in Year 2017 dollars. The above future scenario assumes raw sludge cake from Missouri River WWTF will be hauled to the Regional Facility. 8 Figure 5. Layout of Solids Processing Building Plan Level 1 9 Total System - Regionalization of biosolids treatment is one means of taking advantage of the economies of scale. In addition to helping reduce overall capital expenditures, operations and maintenance costs can be reduced through economies in staffing. Rather than implement solids processing facilities at individuals plants, on the surface a regional solids processing facility may have advantages. However, practical barriers arise in the transport of solids from Lemay WWTF to Bissell Point WWTF. Also, permitting issues arise regarding consolidation of emission sources becoming a New Point Source. Sub-Regional Solids Processing Facility – Bissell Point (SMP TM-1 B-2) The decentralized solids treatment alternatives for the WWTFs involve treatment and disposition of solids at the individual plants. Details of sludge treatment processes and equipment sizing for the decentralized options can be found in the Solids Processing Alternative Evaluation TM’s 1 through 5 for each treatment facility. To compare the overall economics of decentralized treatment with a sub- regional system, base case solids treatment schemes were identified for the individual plants from the range of biosolids treatment options evaluated. Landfilling of dewatered cake or ash was used as the default disposal method for all base case options. Table 3 summarizes the base case options considered for the individual plants. For comparison purposes only Bissell Point (TM-1) and Lemay (TM-2) non- regional options will be explored in more detail since they represent the majority of costs. Table 3. Base Case Solids Treatment Schemes for Individual Plants Facility Treatment Alternative Bissell Point WWTF FBI + CFG Solids processing includes co-thickening, centrifuge dewatering, and fluidized bed incineration. No energy recovery as steam or power. Lemay WWTF FBI + CFG Solids processing includes co-thickening, centrifuge dewatering, and fluidized bed incineration. No energy recovery as steam or power. Coldwater WWTF Current Operation Thickened solids will be pumped to the Bissell watershed for processing at the Bissell Point WWTF. Missouri River WWTF Current Operation All solids processing improvements included with the Secondary Treatment Expansion and Disinfection Facilities and the Digester Rehabilitation projects are considered existing. Additional cogeneration capacity required at projected design year digester loadings is included. Lower Meramec WWTF Co-thickening + Anaerobic Digestion Solids processing involves re-use of existing gravity thickeners for Primary Sludge (PS) and Waste Activated Sludge (WAS) co-thickening followed by new anaerobic digesters for solids stabilization, and use of digester gas for cogeneration. (Note: the digester option is presently not considered due to changing disposal from landfilling to incineration). Dewatering facilities are not included since dewatering was not evaluated as part of Phase II evaluations. Bissell Point Location - Based on SMP Ph II TM-1, the new Sub-Regional Solids Processing Facility for the Bissell Point and Coldwater Service Areas will be located in the existing Bissell Point WWTF and is proposed to be sited east of the Administration Building and existing incinerators, west of the 10 ash lagoons, as shown in Figure 6. It will have three FBI’s and a solids offload area. The Sub- Regional Facility may receive dewatered solids from Lemay WWTF when Lemay has insufficient incineration capacity. Otherwise, the Sub-Regional Facility will only dewater Bissell Point WWTF’s solids (including Coldwater undigested solids). Figure 6. Sub-Regional (Bissell Point) Solids Facility Site Plan Bissell Point Solids Quantities - Initially, the planning team used the future solids quantities from Table 1-2 of the Phase I – TM-2 Facility Summaries and Solids Projections for this evaluation. This data is presented in Table 4 for Bissell WWTF and includes sludge from Coldwater WWTF, which pipes its sludge to Bissell WWTF. Per TM-2, the solids quantities were estimated using modeling and included biological nutrient removal. 11 Table 4. Sub-Regional (Bissell Point) Projected Solids Quantities Parameter VS % of TS1 VS (dtpd)1 TS (dtpd)1 Primary Solids 59.0 59.0 36.6 44.3 62.0 75.0 WAS Solids 55.0 55.0 13.5 26.4 24.5 48.0 Total Solids2 58.2 58.0 51.9 73.0 89.1 125.7 1Annual Average|Maximum Month 2Total Solids includes hauled wastes The MSD planning team compared the TM-2 data to solids quantities obtained from MSD’s Water Information System (WIMS) database for 2006 through 2017. The WIMS data indicated that the annual average of Bissell Point WTTF total solids is 105.6 dtpd, versus 89.1 dtpd in the TM-2, which significantly increases the required capacity by 21%, not considering the maximum month being much higher. The increased solids may be attributed to the addition of high-load years. It should be noted that the County WWTFs began hauling sludge to Bissell WWTF in July 2015; however, the County WWTF sludge was excluded from the WIMS data set. The planning team further evaluated the WIMS solids data to verify the required FBI sizing and number of units. Figure 7 shows a percentile graph, using the Bissell solids data from WIMS. For this graph, 2017 data was left out because a 2017 gate failure caused a high influx of river solids. Additionally, the data excludes sludge that was hauled from the Lower Meramec, Grand Glaize, and Fenton WWTFs, which primarily occurred starting in July 2015. This data was excluded because Lower Meramec Watershed solids will not be hauled to Bissell Point WWTF with this solids handling option. Figure 7: Bissell Sludge Production Percentile (Per WIMS Data) 12 Based on the WIMS data analysis, the planning team believes that Bissell should be able to meet peak sludge incineration demands with two 120 dptd FBIs (240 dptd total). Figure 7 indicates that the maximum daily load, monthly average, 7-day average, and 3-day average exceed 240 dtpd. However, during high flows, the sludge has low volatiles content due to river inflow through the flood gates. Bissell Point WWTF is currently able to meet high flow demands with its existing 240 dtpd capacity MHIs, where the overall sludge loading rate is increased but the volatile solids loading rate is comparable to typical operations. Thus, the planning team anticipates that the FBIs will be able to accommodate similar sludge loading. The design engineer should consider this within system capacities and solids handling bottlenecks. The design engineer should also consider different sizing alternatives that would best meet the normal and peak operating scenarios. For instance, the planning team considered using three 80 dtpd FBIs, sludge storage, and/or additional I/I controls. All alternative options should have a comparable cost to the two 120 dptd FBIs and provide uniform equipment to ensure the ease and consistency of operation and maintenance activities. The design engineer should also consider how additional storage or incinerator capacity will be added in the future with increased sludge production from future nutrient removal projects. The design engineer should evaluate the need for side stream treatment of the centrifuge filtrate to avoid adding to the plant nutrient load. See Section 5.1.1 in the main text for details on MSD’s planning efforts for nutrient removal. Solids Processing Evaluation - Implementation of the Bissell Point Sub-Regional Solids Processing Facility will require two FBIs to provide a peak capacity of 240 dtpd (120 dtpd each). As mentioned above, the design engineer should verify sizing and evaluate potential sludge storage options to best accommodate normal and peak sludge production. Replacement of the existing belt filter presses with centrifuges is recommended to improve incineration efficiency. For sizing dewatering equipment, a thickened sludge concentration of 1.5 % was used. The average annual thickened sludge flow rate was 1.41 mgd and the maximum month was 2.00 mgd. A cake TS concentration of 35 percent was used for cake handling equipment sizing assuming 98% solids capture by the centrifuges. The receiving cake storage is sized to provide three days storage at annual average conditions. All equipment is assumed to operate continually (8,760 hr/yr). The solids management processes evaluation included the following facilities:  dewatering centrifuges  dewatered cake equalization and pumping  dewatered cake receiving and handling  fluidized bed incinerators (FBIs) and blowers  air pollution control (wet scrubber)  heat recovery exchangers and boiler  power generation  advanced air pollution control (fine particulate and mercury removal with dry ash handling) Refer to the SMP Phase II TM-1 (see Appendix D) for detailed process flow schematic Figures B1 to B5. Figure 8 below illustrates the overall process flow diagram for the Sub-Regional Solids Facility. Note that the Cake Receiving Bin is where hauled solids are off-loaded. 13 Figure 8. Sub-Regional (Bissell Point) Solids Process Flow Diagram Technologies for Solids Processing Evaluation - The solids processing technologies selected for the Regional Facility are discussed in the following sections. a) Solids Thickening - The existing primary clarifiers have sufficient capacity to co-thicken PS and WAS at current conditions. The existing sludge wells will be sufficient. The existing twelve gravity belt thickeners have not been in operation since 1994 and would need to be evaluated if they are needed for future use. It is important to consider the future conversion from trickling filters to a Biological Nutrient Removal system with phosphorus removal will preclude the use of the primary clarifiers for co-thickening PS and WAS. Co-thickening has the potential to release phosphorus thereby reducing the overall phosphorus removal. It is recommended that WAS be thickened separately with the existing gravity belt thickeners. b) Dewatering - The existing belt filter presses and pumps (Table 1-5 TM-1) are expected to have adequate capacity to process future solids quantities. However, based on age and expected life of the existing equipment, the dewatering equipment will need to be replaced or significantly overhauled to serve the FBI’s. If so, it will be preferable to replace the ten belt filter presses with six centrifuges. The new dewatering system specified below is based on Table 1-6 of TM-1. Number of centrifuges 6 (4@AA, 5@MM) Maximum solids loading rate (dtpd ea) 25.1 Feed Solids (%) 1.5 Cake Solids (%) 35 Polymer use (lb/dt ea) 15 - 25 Number of centrifuge feed pumps 6 (4@AA, 5@MM) 14 Pump type Centrifugal variable drive Flow (gpm ea) 280 c) Cake Conveyance and Storage System - A new cake conveyance and storage system will transfer centrifuged cake to inject into the incinerators. It will also receive dewatered cake hauled from other facilities. The primary components of this system include cake conveyors, equalization bins, cake transfer pumps, storage silos, and cake injection pumps. Specifications may be found in TM-1 Table 1-8. d) Incinerator Systems - Two fluidized bed incinerator (FBI) trains of 120 dtpd capacity each will be installed in the new Solids Processing Building. Supplemental firing with natural gas will be provided as needed for preheating and to maintain combustion temperature. Refer to previous Figure 8 for an illustration of the incineration process. The incinerators are sized such that one of the two incinerator trains must be operated fairly continuously to process annual average solids quantities. Both incinerators must be operated to process maximum month solids quantities. Some additional capacity is provided for hauled sludge cake. Preliminary equipment design criteria for the FBI units are as follows: Number of FBI trains 2 Throughput capacity (dtpd ea) 120 Incinerator vessel type Insulated fire brick lined w/refractory brick Windbox Arch, hot air Size, D x H (ft) 34 x 45 Minimum natural gas (psig) 10 Discharge temperature (°F) 1,500 to 1,650 max e) Heat Recovery - Primary and secondary heat exchangers (HEX) will recover waste heat from the exhaust gases. The primary HEX will transfer heat to the fluidizing air input. Preliminary design criteria for the HEX’s are as follows: Number of primary HEX 2 Type Shell and tube Configuration Vertical, counterflow Exhaust gas in/out (°F) 1,650/1,200 Fluidizing air in/out (°F) 60/1,030 Size, D x H (ft) 12 x 30 Air pressure (psig) 10 Number of secondary HEX 2 Type Shell and tube Configuration Vertical, counterflow Exhaust gas in/out (°F) 1,200/1,050 Scrubber outlet gas in/out (°F) 100/300 Size, D x H (ft) 12 x 30 Air pressure (psig) 10 f) Air Pollution Control Equipment - Exhaust gases leaving the primary HEX’s will be directed to the Air Pollution Control Equipment that include quench sprays and wet scrubbers. Preliminary equipment criteria for the wet scrubbers are as follows: Number of wet scrubbers 2 Type Combined impingement tray and multiple fixed venturis Configuration Vertical, upflow 15 Size, D x H (ft) 14 x 30 Quench spray flow (gpm) 150 Under tray spray flow (gpm) 60 Impingement tray spray flow (gpm) 1,650 Venturi section flow (gpm) 200 Mist eliminator flow (gpm) 15 Each incinerator will have a dedicated blower to supply fluidizing air drawn from outside the Solids Processing Building. The blowers will be multiple-stage, centrifugal compressors with direct drive 700 hp motors. The required flow rate is 13,000 scfm at 8 psig for each train. Further specification tables for various sub-systems are provided in TM-1 as follows: Table 1-17 Ash Slurry Tanks and Pumps (58% VS basis) Table 1-19 Fuel Oil Storage Tank and Pumps Table 1-20 Sand System Tanks and Transporters Waste heat from the exhaust gases will be used to generate steam in the Waste Heat Boilers. The steam will be used for heating/cooling or to generate electricity. The boilers are placed downstream of the primary HEX as shown in Figure 9 below. The power generation option equipment are also shown. Figure 9. FBIs with Optional Steam and Power Generation Preliminary equipment design criteria for the waste heat boilers producing high quality steam are as follows: 16 Number of boilers 2 Type Water tube Flue gas pressure (psia) 14.7 Flue gas inlet temperature (°F) 1,150 Flue gas outlet temperature (°F) 500 Flue gas flow rate (pph ea) 111,550 Steam pressure (psia) 400 Steam temperature (°F) 600 (superheated) Steam flow rate (pph ea) 11,800 Specifications for various sub-systems are provided in TM-1 as follows: Table 1-22 Packaged Water Treatment System and Pumps Table 1-23 Waste Heat Fly Ash Transport System Table 1-24 Steam Turbine Generator (1.0 MW) Table 1-25 Steam Condenser and Condensate Pumps Table 1-26 Cooling Water Heat Exchanger Table 1-27 Condensate Handling System g) Advanced Air Pollution Control System - It is anticipated that advanced air pollution controls will be required for removal of mercury from incinerator exhaust gases. The exhaust gases from the secondary heat exchanger will be directed to the advanced air pollution control system. Air pollution control equipment for mercury removal includes an exhaust gas conditioning tower, carbon injection tower, carbon storage, fabric filter (followed by previously described wet scrubber), dry ash system, and an induced draft (ID) fan. Figure 10 shows the main mercury scrubbing process using powdered activated carbon (PAC) injection and a fabric filter. Advanced Air Pollution Controls may also be needed for other pollutants such as cadmium and nitrogen oxides. 17 Figure 10. Advanced Air Pollution Control System with Mercury Scrubbing Descriptions of the various advanced air pollution control equipment required for a powdered carbon injection system are included below referencing the detailed tables from TM-1. Table 1-29 Gas Conditioning Tower Table 1-30 Carbon Injection and Storage Table 1-31 Fabric Filter System Table 1-32 Dry Ash System Table 1-33 Induced Draft Fans The single stage, centrifugal, induced draft fans require 350 hp motors to deliver 34,000 acfm at 40 in. w.c. The two bag filters each require a housed space of 55 x 42 x 14 feet. Layout Plans - The layout of the new Solids Processing Building is shown as Figure 11 on the next page. This layout is for the ground floor of the four level building and shows the footprint of major components. Other level layouts may be found in Appendix C of TM-1. The footprint of the main building with incinerators, centrifuges, scrubbers, and sludge load-in is 250 ft by 175 ft. Peripheral systems require an additional 50 ft by 65 ft building. 18 Figure 11. Layout of Bissell Point Solids Processing Building Plan Level 1 19 Bissell Point Cost Summary - Table 5 presents the Engineer’s Opinion of Costs for construction, annual operation and maintenance, annual savings with biosolids use, and life cycle costs from Table 1-34 in TM-1. These costs and benefits were developed and presented in the detailed SMP Ph II TM-9 Opinions of Costs for Alternatives. All costs and savings are in 2010 dollars for a 20-year service life. Alternatives are incremental cost and benefits applied to the base case of fluidized bed incinerators with dewatering centrifuges. To obtain costs in 2017 dollars, a factor of 1.28 will apply. For example, the capital cost for the base case with steam and AEC would be $ 189.3 million in Year 2010 dollars and $ 242.3 million in Year 2017 dollars. Table 5. Costs Summary of Sub-Regional Bissell Point Facility (in $1,000,000) Alternative FBI + CFG Add Steam Add Power Add AEC Capital $ 150.1 $ 13.4 $ 29.0 $ 25.8 Salvage Value ($ 1.3) ($ 0.4) ($ 0.2) ($ 0.4) O & M $ 96.4 $ 4.4 $ 8.1 $ 3.1 Revenue ($ 0.0) ($ 7.3) ($ 4.4) ($ 0.0) Total Present Worth Costs $ 245.2 $ 10.1 $ 32.5 $ 28.5 Sub-Regional Solids Processing Facility – Lemay (SMP TM-2 L3) Lemay Facility Location - The new Sub-Regional Solids Processing Facility for the Lemay Service Areas will be located in the existing Lemay WWTF and is proposed to be sited east of the Administration Building and existing incinerators, as shown in Figure 12, on MSD property known as the Former Defense Mapping Site. However, the design engineer should consider alternative locations with the Lemay WWTF (e.g., the abandoned Grit and Screening Building). The facility will have two FBI’s of 70 dtpd capacity each, centrifuge dewatering, and a solids offload area. The proposed Lemay Sub-Regional Facility may receive dewatered solids from Bissell WWTF when Bissell has insufficient incineration capacity. Processing of the Lower Meramec solids at Lemay was not included in the facilities sizing in the 2010 Comprehensive Solids Handling Master Plan. This will be addressed in forthcoming sections. 20 Figure 12. Sub-Regional Lemay Solids Facility Site Plan Lemay Solids Quantities - The future solids quantities used for this evaluation were carried forward from TM-2, and the Solids quantities for the Lemay WWTF and the Lower Meramec Service Area (LMSA) are presented in Table 6 below. (TM-2 can be found in Appendix E.) Table 6. Sub-Regional (Lemay) Projected Solids Quantities With Lower Meramec Service Area Parameter VS % of TS1 VS (dtpd)1 TS (dtpd)1 Lemay TS 50.5 45.5 25.8 42.8 51.1 94.0 LMSA TS 75.0 75.0 29.3 40.0 39.1 53.2 Future Lemay Solids 61.1 56.3 55.1 82.8 90.2 147.2 1Annual Average|Maximum Month 21 The MSD planning team compared the TM-2 data to solids quantities obtained from the WIMS database for 2006 through 2007. The WIMS data indicated that the annual average of total solids is 66.3 dtpd versus 90.2 dtpd in the TM-2. Thus, MSD evaluated the WIMS solids data for Lemay and LMSA to verify the FBI sizing and number of units. Figure 13 shows a percentile graph, using the WIMS data for Lemay from April 2007 to 2017. Based on this information, the planning team decided that Lemay should be able to operate with two 70 dtpd incinerators. Figure 13: Lemay Sludge Production Percentile (Per WIMS Data) The design engineer should consider different sizing alternatives that would best meet the normal and peak operating scenarios. All alternative options should have a comparable cost to the two 70 dptd FBIs and provide uniform equipment to ensure the ease and consistency of operation and maintenance activities. The design engineer should also consider whether additional storage or incinerator capacity will be needed in the future with increased sludge production from future nutrient removal projects. The design engineer should evaluate the need for side stream treatment of the centrifuge filtrate to avoid adding to the plant nutrient load. See Section 5.1.1 in the main text for details on MSD’s planning efforts for nutrient removal. Additionally, the design engineer should consider impacts to FBI sizing from Lemay’s future high rate clarification facility. See Section 2.2.4 for more details on the facility. Lemay Solids Processing Evaluation - Lemay will require two FBIs to provide a peak capacity of 140 dtpd (70 dtpd each). However, this capacity may be altered after further evaluation of solids contributions from nutrient removal and wet weather CSO tunnel dewatering. As mentioned above, the design engineer should verify sizing and evaluate potential sludge storage options to best accommodate normal and peak sludge production. Replacement of the existing belt filter presses with centrifuges is recommended to improve incineration efficiency. It is assumed 22 otherwise that roughly the same major equipment will be located at each facility.2 Lemay Cost Summary - Table 7 presents the Engineer’s Opinion of Costs for construction, annual operation and maintenance, annual savings with biosolids use, and life cycle costs from Table 2-34 in TM-2. These costs and benefits were developed and presented in the detailed SMP Ph II TM-9 Opinions of Costs for Alternatives based on two FBI trains of 70 dtpd located at Lemay WWTF. All costs and savings are in 2010 dollars for a 20-year service life. Alternatives are incremental cost and benefits applied to the base case of fluidized bed incinerators with dewatering centrifuges. The separate costs for heat recovery could not be determined from the SMP tables for the Lemay facility. Because those costs are minor, they may be scaled as needed from the other facilities with minimal error. To obtain costs in 2017 dollars, a factor of 1.28 will apply. For example, the capital cost for the FBI base case with centrifuges and AEC would be $ 144.8 million in Year 2010 dollars and $185.3 million in 2017 dollars. Table 7. Costs Summary of Sub-Regional Lemay Facility (in $1,000,000) Alternative FBI + CFG Add Power Add AEC Capital $ 121.2 $ 24.2 $ 23.6 Salvage Value ($ 1.0) ($ 0.2) ($ 0.4) O & M $ 61.2 $ 7.0 $ 3.7 Revenue ($ 0.0) ($ 2.3) ($ 0.0) Total Present Worth Costs $ 181.4 $ 28.7 $ 26.9 Summary of Incineration Alternatives Costs Cost Comparison - Table 8 presents the capital costs for the regional and sub-regional alternatives. Cost in 2017 dollars were determined by applying a factor of 1.28 to 2010 dollars to account for inflation. Table 8. Escalated Capital Costs of Incineration Facilities Alternative FBI + CFG Add Steam Add Power Add AEC In 2010 million dollars Regional $ 206.6 $ 20.6 $ 41.2 $ 37.9 Bissell Point1 $ 150.1 $ 13.4 $ 29.0 $ 25.8 Lemay1 $ 121.2 $ 10.82 $ 24.2 $ 23.6 In 2017 million dollars Regional $ 264.4 $ 26.4 $ 52.7 $ 48.5 Bissell Point $ 192.1 $ 17.2 $ 37.1 $ 33.0 Lemay $ 155.1 $ 13.8 $ 31.0 $ 30.2 1Sub-regional facilities. 2Scaled from FBI + CFG costs of Bissell Point 2 MSD would like the centrifuges to be placed at a higher elevation than the incinerator and bins to avoid using pumps for dewatered sludge. Dewatered sludge may be transferred from the centrifuges by conveyors or shaftless screw conveyors. Appendix B – County Facility Alternatives 1 County Facility Alternatives This appendix includes an evaluation of sludge handling options at county facilities based on updated information regarding the capital cost of digestion. It was determined that the digester costs reported in the Solids Handling Master Plan were high. Thus, the digestion cost estimates from Chapter 6 of the Pre-Design Report, “Grand Glaize Sludge Odor Reduction,” (SOR-PDR) study were used. Chapter 6 of the SOR-PDR can be found in Appendix G. Anaerobic Digestion of Solids in the Lower Meramec Service Area The following text was excerpted from Chapter 6 of the SOR-PDR. The addition of high-rate mesophilic anaerobic digestion of combined, thickened primary solids and WAS was considered at both the Grand Glaize and Lower Meramec WWTFs. New WAS thickening facilities were included at both WWTFs based on the assumption that future nutrient removal improvements would include biological phosphorus removal and denitrification. The new facilities included:  Rotary drum thickeners (RDTs) with feed system and building  Anaerobic digestion tanks and associated process equipment  Heating with digester gas-fired hot water boilers  Disposal of Class B sludge cake by hauling to a landfill Grand Glaize WWTF Digesters - Conceptual design solids flows and loads for anaerobic digestion at Grand Glaize are summarized in Table 1 (see SOR-PDR Table 6.1). Table 1. Solids Flows and Loads – Anaerobic Digestion at Grand Glaize Annual Avr. Max. Month WAS to Thickening (ppd@0.6 % TS) 6,300 8,700 (gpd@0.6 % TS) 125,900 173,900 Total Thickened Solids to Digestion (ppd@5 % TS) 19,000 26,000 (gpd@5 % TS) 45,600 62,400 Digested Solids to Dewatering (ppd@3 % TS) 11,400 15,600 (gpd@3 % TS) 45,600 62,400 Dewatered Solids to Landfill Disposal (dtpd@20 % TS) 5.1 7.0 (wtpd@20 % TS) 25.7 35.1 WAS thickening and digestion process parameters and equipment are summarized below based on SOR-PDR Table 6.2. Number of RDT trains 1 operating + 1 standby RDT capacity 200 gpm each 2 WAS thickening building size 1,500 sqft Number of digesters 3 Tank diameter 55 feet Tank sidewall height 31.5 feet Operating volume 0.49 Mgal each Hydraulic residence time 16 to 32 days Digester building size 5,000 sqft (2-story) Gas production 121,600 cf/day Number of boilers 1 operating + 1 standby Heat produced 80 MMBTU/day A preliminary site plan showing new WAS thickening and anaerobic digestion facilities at Grand Glaize WWTF is shown on Figure 1 below. Figure 1. Preliminary Site Plan for Anaerobic Digestion at Grand Glaize WWTF Construction and total project costs for anaerobic digestion at Grand Glaize are summarized in SOR-PDR Table 6.3 (not shown). The total capital costs are $ 22,267,000 in 2017 dollars. Lower Meramec WWTF Digesters - Conceptual design solids flows and loads for anaerobic digestion at Lower Meramec WWTF alternative are summarized in Table 2 (see SOR-PDR Table 6.5). The load at Lower Meramec WWTF, which includes Fenton flow, is 1.8 times greater than the Grand Glaize WWTF load. 3 Table 2. Future Solids Flows and Loads – Anaerobic Digestion at Lower Meramec WWTF AA MM WAS to Thickening (ppd@0.8 % TS) 15,200 21,300 (gpd@0.8 % TS) 227,800 319,200 Total Thickened Solids to Digestion (ppd@5 % TS) 26,000 34,300 (gpd@5 % TS) 82,300 115,100 Digested Solids to Dewatering (ppd@3 % TS) 20,600 28,800 (gpd@3 % TS) 82,300 115,100 Dewatered Solids to Landfill Disposal (dtpd@20 % TS) 9.3 13.0 (wtpd@20 % TS) 46.4 64.8 WAS thickening and digestion process parameters and equipment are summarized below based on SOR-PDR Table 6.6. Number of RDT trains 1 operating + 1 standby RDT capacity 400 gpm each WAS thickening building size 1,500 sqft Number of digesters 3 Tank diameter 67 feet Tank sidewall height 37.8 feet Operating volume 0.88 Mgal each Hydraulic residence time 16 to 32 days Digester building size 7,200 sqft (2-story) Gas production 219,200 cf/day Number of boilers 1 operating + 1 standby Heat produced 132 MMBTU/day A preliminary site plan showing new WAS thickening and anaerobic digestion facilities at Lower Meramec WTTF is shown on Figure 2 below. 4 Figure 2. Preliminary Site Plan for Anaerobic Digestion at Lower Meramec WWTF Construction and total project costs for anaerobic digestion at Lower Meramec WWTF are summarized in SOR-PDR Table 6.7 (not shown). The total capital costs are $ 28,578,000 in 2017 dollars. On-Site Alternative Summary - The on-site digestion alternative for Grand Glaize and Lower Meramec WWTFs do not exist separately because both facilities need to produce stabilized sludge for disposal. Costs of both facilities together need to be considered against the other alternatives to be presented. As such, the total summed capital cost from SOR-PDS Table 6.8 is $ 50,845,000. Regionalization of Anaerobic Digestion at Lower Meramec WWTF - An alternative to separate anaerobic digestion at Grand Glaize and Lower Meramec WWTFs involves conveyance of solids from Grand Glaize WWTF to Lower Meramec WWTF and combined digestion at Lower Meramec of solids from both WWTFs. For this alternative, it is assumed that Grand Glaize WWTF solids would be conveyed in a new force main to the planned Fenton Tunnel drop shaft and conveyed along with the raw wastewater flow in the tunnel to Lower Meramec. Solids flows and loads for the regionalized digestion alternative were estimated by summing Grand Glaize and Lower Meramec flows and loads used in Table 1 and Table 2. Solids flows and loads for the regionalized digestion alternative are summarized below in Table 3. 5 Table 3. Solids Flows and Loads – Regionalized Anaerobic Digestion at Lower Meramec AA MM WAS to Thickening (ppd@0.7 % TS) 21,500 30,000 (gpd@0.7 % TS) 353,700 493,100 Total Thickened Solids to Digestion (ppd@5 % TS) 53,300 74,000 (gpd@5 % TS) 127,800 177,500 Digested Solids to Dewatering (ppd@3 % TS) 32,000 44,400 (gpd@3 % TS) 127,800 177,500 Dewatered Solids to Landfill Disposal (dtpd@20 % TS) 14.4 20.0 (wtpd@20 % TS) 72.0 99.9 WAS thickening and digestion process parameters and equipment are summarized below based on SOR-PDR Table 6.10. Number of RDT trains 1 operating + 1 standby RDT capacity 400 gpm each WAS thickening building size 1,500 sqft Number of digesters 4 Tank diameter 68 feet Tank sidewall height 38 feet Operating volume 0.92 Mgal each Hydraulic residence time 16 to 29 days Digester building size 7,200 sqft (2-story) Gas production 340,800 cfd Number of boilers 1 operating + 1 standby Heat produced 204.5 MMBTU/day A preliminary site plan showing new regional WAS thickening and anaerobic digestion facilities at Lower Meramec WTTF is shown on Figure 3 below. 6 Figure 3. Preliminary Site Plan for Regionalized Anaerobic Digestion at Lower Meramec WWTF Construction and total project costs for regionalized anaerobic digestion at Lower Meramec WWTF are $ 34,207,000 in 2017 dollars. Project costs for the new pipeline facilities to convey solids from Grand Glaize WWTF to the Fenton drop shaft will be developed in the next section. Nutrient Removal Solids Production Impacts - The previous estimates of solids production in the SOR-PDR report did not include impacts of future nutrient removal scenarios as stated “Since nutrient removal impacts on sludge production will be dependent on the type of treatment, future solids production numbers presented in this section do not reflect incorporation of nutrient removal.” For the Grand Glaize WWTF, the following future nutrient removal impacts were noted: “The use of methanol will result in a slight increase in the WAS. It is important to note that when methanol is used for denitrification the increase in WAS yield is slight, but poor methanol feed control can result in high additional solids yield resulting from methanol being consumed under aerobic conditions.” “Chemical addition for phosphorous removal will increase the total sludge on average by approximately 1,000 lb/day based on an anticipated chemical dosage of 13.6 mg/L and a total desired phosphorus residual of 1 mg/L.” For the Lower Meramec WWTF, including the Fenton WWTF design flow, the following future nutrient removal impacts were noted: “WAS volume is likely to decrease slightly compared to the existing trickling filter operation. Although nitrification is occurring in the existing trickling filters, a Nitrification/Denitrification and Biological Nutrient Removal system do have lower yields since the total sludge age is higher.” “Chemical addition for phosphorous removal will increase the total sludge on average by approximately 2,000 lb/day based on an anticipated chemical dosage of 17.1 mg/L and a total desired phosphorus residual of 1 mg/L.” The summed solids production from phosphorus precipitation would be 1.5 tons per day. In comparison, this is a minor increase to the projected solids quantity for Lower Meramec of 39.1 7 dtpd from Appendix A, Table 6. However, updated information on nutrient removal sludge production can be found in the Comprehensive Ammonia and Nutrient Master Plan. Sludge Transfer Force Main: Grand Glaize WWTF to Riverside/Yarnell Trunk Sewer - To further evaluate the Regional Solid’s Facility at Lower Meramec WWTF, a preliminary design and cost estimate was prepared for constructing a sewage sludge force main between Grand Glaize WWTF and the Riverside/Yarnell gravity trunk sewer. A map of the alignment is found in Appendix I along with cost estimate details. Once the sludge enters the Riverside/Yarnell trunk sewer, it will flow to the future Fenton drop shaft, where it will enter the Lower Meramec Tunnel Phase II, along with the flow presently tributary to the Fenton WWTF. Specifics of the preliminary force main and booster pump stations are as follows: Sludge loading rate 3,200 dtpy (8.8 dtpd) Sludge concentration 2 % w/w solids Sludge flow rate 105,060 gpd (0.16 cfs) Number of pump stations 2 Pump motor size 30 HP Length of force main 23,400 feet Pipe type 6-inch HDPE SDR 11 Sludge residence time 6.2 hr The total estimated costs are $ 12,370,000 in 2017 dollars. The planned place in service date is 2024 to coincide with the completion of the Lower Meramec Tunnel and the decommissioning of the Fenton WWTF. Sludge Transfer Force Main: Lower Meramec WWTF to Lemay WWTF - To complete the sub-regional alternative for Lemay incineration, raw or digested sludge has to be transported from Lower Meramec WWTF to Lemay WWTF. Because it is undesirable to have hauling as the long-term alternative, a preliminary design and cost estimate was prepared for constructing a sewage sludge force main between Lower Meramec WWTF and Lemay WWTF. A map of the alignment is found in Appendix I along with cost estimate details. Highly diluted sludge will enter the Lower Meramec WWTF pump station via the Lower Meramec Tunnel from Grand Glaize WWTF, where it will be lifted to the primary clarifiers. Primary Sludge and WAS from the secondary clarifiers (assuming the trickling filters will be replaced with activated sludge due to nutrient removal requirements) will be co-thickened in the gravity thickeners, then pumped to Lemay WWTF through the new force-main. Specifics of the preliminary force main and booster pump stations are as follows: Sludge loading rate 6,120 dtpy (16.8 dtpd) Sludge concentration 2 % Sludge flow rate 201,000 gpd (0.31 cfs) Number of pump stations 3 Pump motor size 30, 40, 50 HP Length of force main 53,250 feet Pipe type 6-inch HDPE SDR 11 Sludge transit time 7.4 hr The total estimated costs are $ 23,400,000 in 2017 dollars. The planned place in service date is 2024 to coincide with the construction of FBI’s at the Lemay WWTF. Note: consideration was given to using the Jefferson Barracks Tunnel to convey the sludge and significantly reduce the 8 length of new force main. However, due to current nutrient removal strategies and anticipated minimal nutrient removal required at Lemay WWTF, this was not an option. Therefore, the sludge force main from Lower Meramec WWTF must be taken to the location of sludge handling within the Lemay facility. Redundant Sludge Transfer Force Main: Coldwater WWTF to Redman Road – Thickened sludge from Coldwater WWTF is presently pumped to the Bissell Point collection system via 17,500 feet of 8-inch ductile iron force main. This pipe has corroded and pipe wall thinning measurements indicate it is near the end of its useful life. The force main discharges to a 15-inch VCP gravity sewer located in Hathaway Trails common ground. To maintain the long-term solids solution, the force main must be replaced with a redundant force main at a cost of $ 8,500,000. There are no booster pump stations along the force main. The only pumping occurs at the Coldwater WWTF and at the headworks of Bissell Point WWTF. Appendix C – Solids Handling MP TM-6 (Regional Bissell) BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 1 TECHNICAL MEMORANDUM NO. 6 – REGIONAL FACILITY SOLIDS PROCESSING ALTERNATIVES EVALUATION To: Metropolitan St. Louis Sewer District From: Jim Rowan, Gustavo Queiroz, Patricia Scanlan, Hari Santha This Technical Memorandum presents information on the solids processing and management options evaluated for the Regional Solids Processing Facility as part of developing a strategic plan for long-term management of biosolids. The following sections describe the proposed biosolids management system, the solids quantities used as the basis of the evaluation, the treatment and final use options evaluated for the Regional Facility. Table of Contents 1. Regional Facility – R-1 .............................................................................................................. 4 2. Solids Quantities ........................................................................................................................ 4 3. Solids Processing Evaluation ..................................................................................................... 6 4. Technologies for Solids Processing Evaluation ......................................................................... 7 a) Solids Receiving – R-1 ........................................................................................... 7 a. Thickening and Dewatering .................................................................................. 10 b. Incinerator Systems ............................................................................................... 10 (1) Fluidized Bed Incinerator System – R-1 .................................................................... 10 (2) Primary and Secondary Heat Exchangers – R-1 ........................................................ 12 (3) Air Pollution Control Equipment – R-1 ..................................................................... 13 (4) Ash Handling System – R-1 ....................................................................................... 14 (4) Fluidizing Air Blowers – R-1 ..................................................................................... 16 (5) Fuel Storage Tank and Pumps – R-1 .......................................................................... 16 (6) Sand System – R-1 ..................................................................................................... 18 c. Energy Recovery Options ..................................................................................... 18 (1) Steam Generation – Steam Sale to Trigen Option R-1-A .......................................... 19 (2) Waste Heat Boilers - R-1-A........................................................................................ 20 (3) Water Treatment System - R-1-A ............................................................................... 21 (4) Power Generation Option - R-1-B .............................................................................. 22 (5) Waste Heat Boiler - R-1-B ......................................................................................... 23 (6) Steam Turbine Generator - R-1-B .............................................................................. 25 (7) Steam Condenser - R-1-B ........................................................................................... 26 (8) Cooling Water Heat Exchangers - R-1-B ................................................................... 26 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 2 (9) Condensate Handling System - R-1-B ........................................................................ 28 (10) Water Treatment System - R-1-B ........................................................................... 29 d. Future Advanced Air Pollution Control - R-1-C .................................................. 29 (1) Conditioning Tower - R-1-C ...................................................................................... 32 (2) Carbon Injection and Storage - R-1-C ........................................................................ 33 (3) Fabric Filters - R-1-C ................................................................................................. 34 (4) Dry Ash System - R-1-C ............................................................................................ 35 (5) Induced Draft Fans - R-1-C ........................................................................................ 36 5. Layout Plans............................................................................................................................. 36 6. Site Plan ................................................................................................................................... 36 7. Staffing Requirements ............................................................................................................. 37 8. Cost Summary .......................................................................................................................... 37 9. Total System ............................................................................................................................ 38 (1) Alternative S-2 Lemay Hauling .............................................................................................. 41 (2) Alternative S-3 Lemay Pump Station...................................................................................... 43 c. Cost Summary ....................................................................................................................... 45 List of Tables Table 6-1 Projected Solids Quantities ............................................................................................. 5Table 6-2 Solids Processing Equipment ......................................................................................... 7 Table 6-3 Cake Receiving and Cake Pump Design Criteria ........................................................... 9 Table 6-4 Fluidized Bed Incinerator Design Criteria ................................................................... 11 Table 6-5 Primary and Secondary Heat Exchangers Design Criteria ........................................... 13Table 6-6 Wet Scrubber Design Criteria ...................................................................................... 14Table 6-7 Ash Slurry System Design Criteria .............................................................................. 15 Table 6-8 Fluidizing Air Blower Design Criteria ......................................................................... 16 Table 6-9 Fuel Oil Storage Tank and Pumps Design Criteria ...................................................... 17 Table 6-10 Sand System Design Criteria ...................................................................................... 18Table 6-11 Waste Heat Boiler Design Criteria ............................................................................. 20Table 6-12 Packaged Water Treatment Design Criteria ............................................................... 22 Table 6-13 Waste Heat Boiler Design Criteria (for Power Generation) ....................................... 23 Table 6-14 Steam Turbine Generator Design Criteria .................................................................. 25 Table 6-15 Steam Condenser and Condensate Pumps Design Criteria ........................................ 26Table 6-16 Cooling Water Heat Exchanger Design Criteria ........................................................ 27Table 6-17 Condensate Handling System Design Criteria ........................................................... 28 Table 6-18 Packaged Water Treatment Design Criteria ............................................................... 29 Table 6-19 Gas Conditioning Equipment Design Criteria ............................................................ 32 Table 6-20 Carbon System Design Criteria .................................................................................. 33Table 6-21 Fabric Filter Design Criteria ....................................................................................... 34Table 6-22 Dry Ash System Design Criteria ................................................................................ 35 Table 6-23 Induced Draft Fan Design Criteria ............................................................................. 36 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 3 Table 6-24 Staffing Requirements ................................................................................................ 37 Table 6-25 Costs Summary of Regional Facility ($1000) ............................................................ 38 Table 6-26 Base Case Solids Treatment Schemes for Individual Plants ...................................... 39Table 6-27 Modifications Required to the Base Case Treatment Options at Individual Plants for Implementing the Regional Total System S-2 .............................................................................. 41 Table 6-28 Total System Costs Summary ($1000) ....................................................................... 45 List of Figures Figure 6-1 Solids Process Flow Diagram ....................................................................................... 4 Figure 6-2 Solids Receiving ............................................................................................................ 8 Figure 6-3 Fluidized Bed Incinerator System ............................................................................... 11Figure 6-4 FBIs with Optional Steam Generation – R-1-A .......................................................... 19Figure 6-5 FBI with Optional Power Generation – R-1-B ........................................................... 23 Figure 6-6 Advanced Air Pollution Control System w/ Mercury Scrubbing ............................... 31 Figure 6-7. Solids Process Flow Chart for Decentralized (No Regional) Treatment S-1 ............. 40 Figure 6-8 Solids Process Flow Chart for Alternative S-2 Lemay Hauling ................................. 43Figure 6-9. Solids Process Flow Chart for Alternative S-3 Lemay Pump Station ...................... 44 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 4 1. Regional Facility – R-1 The Regional Facility will receive dewatered solids from Lower Meramec, Missouri River, Coldwater, Lemay and Bissell Point WWTPs. The new Regional Facility will be located in the existing Bissell Point WWTP site (refer to Appendix A, Figure A-1 for the proposed facility location). The dewatered solids from Lemay, Missouri River and Lower Meramec will be hauled to the site while solids processed at the Bissell Point facility (including Coldwater solids) will be pumped to a new Dewatering Building adjacent to the new Solids Processing Building for dewatering and further processing. Figure 6-1 illustrates the overall process flow diagram for the Regional Facility. Figure 6-1 Solids Process Flow Diagram 2. Solids Quantities The solids quantities used for this evaluation were carried forward from Phase I – TM 2: Facility Summaries and Solids Projections for all plants with exception of the Bissell Point and BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 5 Coldwater WWTPs. Solids quantities for the Bissell Point WWTP (including Coldwater WWTP solids) were estimated using wastewater treatment process models. Solids quantities for all plants are presented in Table 6-1 below. Table 6-1 Projected Solids Quantities Parameter Units Max. Month Ann. Avg. Bissell Point and Coldwater WWTPs Total Solids dtpd 125.7 89.1 Volatile Solids Fraction % of TS 58.0 58.2 Volatile solids dtpd 73.0 51.9 Lemay WWTP Total Solids dtpd 94.0 51.1 Volatile Solids Fraction % of TS 45.5 50.5 Volatile solids dtpd 42.8 25.8 Missouri River WWTP Total Solids dtpd 58.0 47.7 Volatile Solids Fraction % of TS 80.2 80.1 Volatile solids dtpd 46.5 38.2 Lower Meramec WWTP Total Solids dtpd 53.2 39.2 Volatile Solids Fraction % of TS 74.9 75.1 Volatile solids dtpd 39.9 29.4 Total Solids Total Solids dtpd 331.0 227.0 Volatile Solids Fraction % of TS 61.0 64.0 Volatile solids dtpd 202.2 145.3 Solids Concentration % 25.0 25.0 Dewatered solids received at the Regional Facility will vary in total solids (TS) concentration and volatile organic composition depending on each plant’s treatment processes. A solids BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 6 concentration of 25 percent TS was used for equipment sizing throughout this evaluation to ensure that sufficient operating and storage volume is provided during low percent TS conditions from the various plants. The expected volatile solids (VS) concentrations in the Bissell Point and Lemay solids are relatively low. The low volatile solids concentration appears to be a result of a high concentration of inorganic material from inflow and/or infiltration for these plants during high flow events. The maximum month (MM) quantities were used as the basis for equipment sizing at the Regional Facility. The mid-point (10-year) annual average quantities were used as the basis for determining the operations and maintenance (O&M) costs for the evaluation. The mid-point average solids quantities are identical to the future annual average solids production since the watersheds for all the plants are mature with minimum future growth. Criteria used for equipment sizing for the regional facility are listed below.  All solids quantities listed in Table 6-1 are as raw solids.  Thickening and dewatering capture rates of 100 percent were used for this evaluation.  A dewatered cake concentration of 25 percent TS was used for equipment sizing.  The biosolids receiving cake storage is sized to provide 3 days storage at annual average conditions. 3. Solids Processing Evaluation The solids management processes for the Regional Facility were developed based on discussions with the District staff and site visits to the treatment plants. This evaluation included new solids processing facilities consisting of cake receiving and handling facilities, incinerator feed pumps, fluidized bed incinerators (FBIs), air pollution control systems and heat recovery. The air pollution control system evaluation includes options for mercury removal and dry ash handling. The heat recovery evaluation includes steam generation and sale to Trigen, a local utility provider and on-site power generation. Refer to Appendix B of this report for detailed process flow schematics. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 7 Implementation of a Regional Solids Processing Facility will require completely new equipment. A summary of the new equipment for the Regional Facility is presented in Table 6-2. Table 6-2 Solids Processing Equipment Cake Receiving and Handling Dewatered Cake Equalization Bins Incinerator Cake Feed Pumps Fluidized Bed Incinerators Air Pollution Control (Wet Scrubber) Advanced Air Pollution Control (Fine Particulate and Mercury Removal with Dry Ash Handling) Odor Control 4. Technologies for Solids Processing Evaluation The solids processing technologies selected for the Regional Facility are discussed in the following sections. a) Solids Receiving – R-1 Dewatered cake will be hauled from the Lemay, Missouri River and Lower Meramec plants using end-dump trucks or trailers. Trucks will enter the 3-bay, enclosed unloading area through overhead doors that are controlled using an identification system, such as a card reader. Hauled cake will be discharged into the solids receiving pit. The solids receiving pit will extend below grade and be separated from the truck unloading area by a short wall, 30 inches tall, which will block trucks from backing into the receiving pit. An overhead bridge crane equipped with a clamshell style bucket will traverse the entire area of the solids pit and will be used to transfer the cake to one of three equalization bins upstream of incineration. Cake transfer will be controlled by an operator in a control room overlooking the biosolids pit. The cake transfer process will be limited to periods when trucks are not unloading. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 8 Each equalization bin will use a sliding frame type live bottom to prevent cake bridging. The equalization bins will discharge to a collection screw conveyor below the sliding frame. The collection screw will feed one of two piston type cake pumps (1 duty, 1 standby). Each piston pump will contain two discharge outlets to evenly split the flow of cake to an incinerator. Figure 6-2 illustrates the receiving process operation. Figure 6-2 Solids Receiving Preliminary equipment design information for the cake receiving facility and cake feed pumps is listed in Table 6-3. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 9 Table 6-3 Cake Receiving and Cake Pump Design Criteria Equipment Units Specifications Solids Receiving Pit Number of Units No. 1 Size Length Width Depth ft ft ft 130 50 15 Capacity1 wt 2,700 Days of Storage (MM Conditions) days 2 Days of Storage (AA Conditions) days 3 Bridge Crane with Clamshell Number of Units No. 2 Bridge crane type Double girder Bridge crane capacity tons 20 Clamshell capacity cy 10 Equalization Bins Number of Units No. 3 Type Vertical cylinders with sliding frame Size Diameter Height ft ft 15 20 Useable capacity dt 30 Cake Pumps Number of Units No. 6 Capacity dtph 5 Flow (each) gpm 85 1 Capacity based on AA conditions at 25 %TS. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 10 a. Thickening and Dewatering No thickening will be provided at the Regional Facility. All thickening will occur at the individual treatment plants. A Dewatering Building will be located adjacent to the Solids Processing Building to dewater sludge pumped from the Bissell Point plant. All other dewatering will occur at the individual treatment plants. b. Incinerator Systems Incinerator systems process dewatered cake by means of high temperature thermal oxidation (combustion). The dewatered cake is pumped to the incinerators that oxidize the organic (volatile) fraction, generating exhaust gases and ash. Descriptions for incinerator system components are presented in the following sections. (1) Fluidized Bed Incinerator System – R-1 Three fluidized bed incinerator (FBI) trains will be installed in the new Solids Processing Building as part of the Regional Facility. Each incinerator vessel will consist of three zones: hot windbox, sand bed, and freeboard. Preheated fluidizing air will be directed into the windbox and distributed to the bed through tuyeres in a refractory arch. The air will fluidize the sand bed above the refractory arch and will provide combustion air for the process. Dewatered cake will be pumped into the incinerator through multiple injection nozzles and into the sand bed. Auxiliary fuel injection lances (fuel oil or natural gas) will provide supplemental fuel, if needed. All exhaust gases, including combustion products and ash, will exit the fluidized bed incinerator through the freeboard and exhaust gas duct. Figure 6-3 illustrates the proposed FBI system. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 11 Figure 6-3 Fluidized Bed Incinerator System The incinerators are sized such that two of the three incinerator trains must be operated to process annual average solids quantities. All three incinerators must be operated to support maximum month solids quantities. No spare capacity is provided at maximum month conditions. Preliminary equipment design information for the FBIs is listed in Table 6-4. Table 6-4 Fluidized Bed Incinerator Design Criteria Equipment Units Specifications Fluid Bed Incinerators Number of Units No. 3 Required Capacity (each) dtpd 120 Incinerator Vessel Type Refractory lined w/ refractory BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 12 Table 6-4 Fluidized Bed Incinerator Design Criteria Equipment Units Specifications Windbox arch Hot Air Size Diameter Height ft 34 45 Wall Construction Inner layer of walls and dome Outer layer of walls and dome Refractory Brick Insulated Fire Brick Number of Solids Feed Nozzles No. Multiple around periphery, 4 minimum Auxiliary Fuel Source Natural Gas and Fuel Oil Minimum Natural Gas Pressure psig 10 Discharge Temperature oF 1,500 - 1,650 max Preheat Provisions Preheat supplied by natural gas or fuel oil fired burner (2) Primary and Secondary Heat Exchangers – R-1 Primary and secondary heat exchangers will recover waste heat from the exhaust gases. The primary heat exchanger will transfer heat from the incinerator exhaust gases to the fluidizing air. A primary heat exchanger bypass (with damper) will control the temperature of the fluidizing air and heat recovery. This “hot windbox” design will reduce the amount of auxiliary fuel required for combustion and, in some cases, may allow autogenous (without additional fuel) combustion. Following the primary heat exchanger, a secondary heat exchanger will transfer heat from the exhaust gases to the scrubber outlet gas. Heating the scrubber outlet gas prior to discharge to the atmosphere will help suppress visible plumes in the incinerator exhaust. The secondary heat exchanger may also be used to pre-heat exhaust to future emission control equipment. Preliminary equipment design information for the primary and secondary heat exchangers is shown in Table 6-5. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 13 Table 6-5 Primary and Secondary Heat Exchangers Design Criteria Equipment Units Specifications Primary Heat Exchanger Number of Units No. 3 Type Shell and Tube Configuration Vertical, Counterflow Design Temperatures Exhaust gas in Exhaust gas out Fluidizing air in Fluidizing air out oF 1,650 1,200 60 1,030 Size Vessel Diameter Height ft 12 30 Design Pressure psig 10 Secondary Heat Exchanger Number of Units No. 3 Type Shell and Tube Configuration Vertical, Counterflow Design Temperatures Exhaust gas in Exhaust gas out Scrubber outlet gas in Scrubber outlet gas out oF 1,200 1,050 100 300 Design Pressure psig 10 (3) Air Pollution Control Equipment – R-1 Exhaust gases leaving the secondary heat exchangers will be directed to the air pollution control equipment. Air pollution control equipment will include quench sprays and wet scrubbers. The quench spray section will consist of multiple water sprays used to cool the exhaust gases prior to entering the wet scrubber. The new scrubber will be a vertical upflow unit with impingement trays used for cooling and saturating the gas, followed by a multiple fixed venturi section with BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 14 water injection and mist eliminators with sprays. Plant effluent water will be used for the impingement trays. Strained plant effluent water will be used for the venturi injection and high pressure spray lances. Service water (potable water downstream of a backflow preventer) will be used for the mist eliminator sprays. Booster pumps will be supplied with the scrubbers for venturi and high pressure spray lance water injection. Strained plant effluent water is required for the venturi injection and high pressure spray lances to prevent nozzle clogging while potable water is required for the mist eliminator to prevent fouling. Preliminary equipment information for the wet scrubber is shown in Table 6-6. (4) Ash Handling System – R-1 For FBIs, a small fraction of the ash is collected at the waste heat boilers (for power generation option only) while the majority of the ash is removed by the wet scrubber. Table 6-6 Wet Scrubber Design Criteria Equipment Units Specifications Wet Scrubbers Number of Units No. 3 Type Combined Impingement Tray, and Multiple Fixed Venturis Configuration Vertical, Upflow Dimensions, ft Diameter Height ft 14 30 Water Requirements (per scrubber) Quench Sprays Under Tray Sprays Impingement Trays Venturi Section Mist Eliminator gpm 150 100 1,650 200 15 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 15 A new ash slurry system including ash slurry pumps and slurry tanks is recommended to handle the ash slurry from the bottom of the scrubber. The new ash slurry system will collect the scrubber drain water including the ash and transfer it to the existing ash lagoons. Preliminary equipment design information for the ash slurry system is listed in Table 6-7. Table 6-7 Ash Slurry System Design Criteria Equipment Units Specifications Ash Slurry Tanks Number of Units No. 3 Material Handled FBI and WHB fly ash Tank Dimensions Length Width Height ft 15’-0” 10’-0” 8’-0” Ash Slurry Concentration % 0.5 to 1 Ash Slurry Pumps Number of Units (per incinerator) No. 6 (3 Duty, 3 Standby) Material Handled Ash Slurry Incinerator Ash Flow Rate pph 4,000 Maximum Flow Rate at Maximum Speed gpm 1,600 Minimum Flow Rate at Reduced Speed gpm 800 Discharge Point Ash Lagoons Discharge Head at Maximum Flow ft 100 Motor hp 70 1 Ash flow rate based on low volatile (60% VS) condition and incinerator capacity. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 16 (4) Fluidizing Air Blowers – R-1 Each incinerator will have a dedicated blower to supply fluidizing air. The fluidizing air will be drawn from outside the Solids Processing Building, and will be preheated in the primary heat exchanger before entering the FBI windbox. Fluidizing air serves two purposes: to suspend the solids in the incinerator bed and to provide combustion air. Preliminary equipment design information for the fluidizing air blowers is shown in Table 6-8. Table 6-8 Fluidizing Air Blower Design Criteria Equipment Units Specifications Fluidizing Air Blowers Number of Units No. 3 Type Multiple-Stage Centrifugal Drive Direct Required Flow scfm 13,000 Flow Adjustment Inlet Damper Pressure Rise psig 8 Motor hp 700 (5) Fuel Storage Tank and Pumps – R-1 Fuel oil will be delivered to the site by tankers and stored in an above ground storage tank located next to the new Solids Processing Building. Fuel oil transfer pumps will be installed in the fuel oil storage area to transfer fuel oil from the storage tank to a day tank. A second set of pumps, fuel oil feed pumps, will be used to transfer fuel oil from the day tank to each incinerator. The fuel oil, which will be used for supplemental fuel during incinerator warm up, will be injected into the incineration process through fuel injection lances. Preliminary equipment design information for the fuel storage tank and pumps is shown in Table 6-9. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 17 Table 6-9 Fuel Oil Storage Tank and Pumps Design Criteria Equipment Units Specifications Fuel Oil Tank Number of Tanks No. 1 Type Double wall, above ground Tank Size Diameter Length ft 12 30 Volume gal 20,000 Fuel Oil Transfer Pumps Number of Units No. 2 (1 Duty, 1 Standby) Type Gear Required Flow gpm 60 Minimum Discharge Pressure psi 5 Motor hp 1 Fuel Oil Day Tank Number of Tanks No. 1 Tank Size Diameter Height ft 6 10 Volume gal 1,600 Fuel Oil Injection Pumps Number of Units No. 3 (2 Duty, 1 Standby) Type AFD, Gear Type Required Flow gpm 4 Minimum Discharge Pressure psi 50 Motor hp 0.5 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 18 (6) Sand System – R-1 Sand will be delivered to the site by truck and stored in indoor sand storage tanks. Pneumatic transporters will convey sand from the sand storage tank to each of the FBIs to replenish sand entrained in the exhaust gas stream. Preliminary equipment design information for the sand storage system is shown in Table 6-10. Table 6-10 Sand System Design Criteria Equipment Units Specifications Storage Tanks Number storage tanks No. 2 Type Vertical with dual conical base Volume1 cf 360 Storage months 1 to 9 Size Diameter Total Height2 ft 9 45 Transporters Number of Pneumatic Transporters No. 2 (per storage tank) Compressed Air Requirements Flow, scfm Pressure range, psig scfm psig 150 100-120 1 Silo capacity based on sand demand of 50 lbs/hr for two incinerators. Feed rate for make up sand range from 5 to 50 lbs/hr. 2 Silo height includes clearances for transport and dust collection equipment. c. Energy Recovery Options Waste heat from the exhaust gases will be used to generate steam in the waste heat boilers. Two end use options for the steam have been evaluated: a) Medium pressure saturated steam for sale to Trigen; b) High pressure superheated steam for power generation. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 19 (1) Steam Generation – Steam Sale to Trigen Option R-1-A For this option, waste heat will be used to generate medium pressure steam that will be sold to Trigen. The waste heat remaining in the flue gas downstream of the primary heat exchangers will be used in waste heat boilers to generate steam. Exhaust gas from the waste heat boiler will be treated by the secondary heat exchanger. Heat removed from the exhaust gas will be transferred to the scrubber outlet gas for plume suppression. Figure 6-4 illustrates the proposed steam generation option. Ultimately a pipeline would need to be constructed along an existing right-of-way corridor in order to convey steam from the Regional Facility to the Trigen Facility located near Laclede’s Landing. It is anticipated that ownership and funding for the construction of this line will be negotiated in the future between MSD and Trigen. Figure 6-4 FBIs with Optional Steam Generation – R-1-A BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 20 (2) Waste Heat Boilers - R-1-A Flue gases from each FBI will be ducted to waste heat boilers. The waste heat boilers will recover heat from the incinerator exhaust gases to produce medium pressure saturated steam. A bypass will be provided around the waste heat boilers to allow the steam production equipment to be taken out of service without affecting incinerator operation. Preliminary equipment design criteria for the waste heat boilers are shown in Table 6-11 Table 6-11 Waste Heat Boiler Design Criteria Equipment Units Specifications Waste Heat Boilers Number No. 3 Type Water Tube Flue Gas Conditions Flue Gas Pressure psia 14.7 Flue Gas Inlet Temperature oF 1,150 Flue Gas Outlet Temperature oF 500 Design Flue Gas Flow1 pph 115,800 (each boiler) Flue Gas Flow at AA Conditions (70% VS and 25% TS) pph 109,500 (each boiler) Flue Gas Flow at AA Conditions (60% VS and 25% TS) pph 97,900 (each boiler) Steam Conditions Steam Pressure psia 180 Steam Temperature oF 373 (saturated) Steam Flow at AA Conditions (70% VS) pph 24,700 (each boiler) Steam Flow at AA Conditions (60% VS) pph 22,600 (each boiler) Waste Heat Fly Ash Transport System (From waste heat boiler to ash storage silo)2 Number of surge hoppers No. 3 Type Vertical with Conical BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 21 Table 6-11 Waste Heat Boiler Design Criteria Equipment Units Specifications Dry ash surge hopper capacity cf Base 1 Number of pneumatic transporters No. 3 Type Air flow Operating pressure scfm psig Dense Phase 15 100 Number of compressors No. 2 (one duty, one standby) Type Compressor capacity Compressor motor scfm hp Scroll or Screw Type 100 10 1 Design exhaust flow rate for waste heat boiler based on incinerator capacity at 70% VS and 25% TS. 2 Required for options with dry ash handling. For options where dry ash handling is not required, the ash transport system will transfer the waste heat boiler fly ash to the wet slurry tanks. (3) Water Treatment System - R-1-A A package type water treatment system will be provided to treat potable water for boiler water make up. The water treatment equipment will depend on the potable water quality and make up water quality requirements. The water treatment system will consist of cartridge filters, carbon filters, water softeners, reverse osmosis (RO), demineralizers, demineralized water storage tank, and make up water pumps. The water treatment systems will include standby components to support 7 day, 24 hour incinerator operation during water system equipment cleaning and regeneration. The water softening and the demineralizer systems will require periodic regeneration; the RO system will require a periodic clean-in-place (CIP). All regeneration and CIP is expected to be performed off-site through a service contract. The calculated capacities for the packaged water treatment system were based on a “once through system” with no condensate return. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 22 Preliminary equipment design information for the packaged water system is shown in Table 6- 12. Table 6-12 Packaged Water Treatment Design Criteria Equipment Units Specifications Water Treatment System Number No. 2 (1 Duty, 1 Standby) Water source Potable Water Required treated water flow rate gpm 150 Design Pressure Loss As required by vendor Make Up Water Tank Capacity gal 9,000 Packaged Water Treatment System Pumps (Booster pumps to waste heat boiler) Number of Units No. 4 (2 Duty, 2 Standby) Water source Treated Water Flow Rate gpm 150 Discharge Pressure ft 600 Motor hp 60 (4) Power Generation Option - R-1-B In this option, waste heat remaining in the exhaust gases after the primary heat exchanger will be used in waste heat boilers to generate high pressure superheated steam. The superheated steam will be used in steam turbines to generate electricity, which will be used on-site to reduce electricity purchases. The generated electricity will be used onsite. Following the waste heat boiler, a secondary heat exchanger will transfer heat from the exhaust gases to the scrubber outlet gas for plume suppression. Figure 6-5 illustrates the proposed power generation option. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 23 Figure 6-5 FBI with Optional Power Generation – R-1-B (5) Waste Heat Boiler - R-1-B Flue gases from the FBI will be ducted to a new waste heat boiler. The waste heat boiler will recover heat from the incinerator exhaust gases to produce high pressure superheated steam for power generation. A bypass will be provided around the waste heat boilers to allow the steam production equipment to be taken out of service without affecting incinerator operation. Preliminary equipment design information for the waste heat boilers is listed in Table 6-13. Table 6-13 Waste Heat Boiler Design Criteria (for Power Generation) Equipment Units Specifications Waste Heat Boilers Number No. 3 Type Water Tube Flue Gas Conditions BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 24 Table 6-13 Waste Heat Boiler Design Criteria (for Power Generation) Equipment Units Specifications Flue Gas Pressure psia 14.7 Flue Gas Inlet Temperature oF 1,200 Flue Gas Outlet Temperature oF 500 Design Flue Gas Flow pph 106,200 Design Flue Gas Flow1 pph 115,800 (each boiler) Flue Gas Flow at AA Conditions (70% VS and 25% TS) pph 109,500 (each boiler) Flue Gas Flow at AA Conditions (60% VS and 25% TS) pph 97,900 (each boiler) Steam Conditions Steam Pressure psia 400 Steam Temperature oF 600 (superheated) Steam Flow at AA Conditions (70% VS)2 pph 20,800 (each boiler) Steam Flow at AA Conditions (60% VS)2 pph 19,000 (each boiler) Waste Heat Fly Ash Transport System (From waste heat boiler to ash storage silo)3 Number of surge hoppers No. 3 Type Dry ash surge hopper capacity cf Vertical with Conical Base 1 Number of pneumatic transporters No. 3 Type Air flow Operating pressure scfm psig Dense Phase 15 100 Number of compressors No. 2 (one duty, one standby) Type Compressor capacity Compressor motor scfm hp Scroll or Screw Type 100 10 1 Design flow rate for waste heat boiler based on incinerator capacity at 70% VS and 25% TS). BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 25 2 Steam flow rates shown include deduction for parasitic loads (i.e., de-aerator, etc.). 3 Required for options with dry ash handling. For options where dry ash handling is not required, the ash transport system will transfer the waste heat boiler fly ash to the wet slurry tanks. (6) Steam Turbine Generator - R-1-B One steam turbine generator will convert steam to electrical power. The skid-mounted steam turbine will be installed in the new Solids Processing Building and will include an oil lubrication system, mounted on a separate skid. Preliminary equipment design information for the steam turbine generator is listed in Table 6-14. Table 6-14 Steam Turbine Generator Design Criteria Equipment Units Specifications Steam Turbine Number No. 1 Type Full condensing to 4 in. Hg absolute Steam conditions Steam Pressure psia 400 Steam Temperature oF 600 (superheated) Design Steam Flow1 pph 50,000 Turbine speed rpm 4,750 Alternator Speed rpm 1,800 Power output – AA (70% VS) MW 2.9 Power output – AA (60% VS) MW 2.6 Output Voltage V 4,160 Type Synchronous 1 Steam turbine sized based on AA conditions for two waste heat boilers operating plus an additional 20 percent steam flow. Steam turbine sized for steam rate prior to parasitic load deduction. Power output based on net steam rate after parasitic load deduction. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 26 (7) Steam Condenser - R-1-B One steam condenser will be provided to condense steam from the turbine. The condensate will be returned to the waste heat boiler steam drum. Preliminary equipment design information for the steam condenser and condensate pumps is listed in Table 6-15. Table 6-15 Steam Condenser and Condensate Pumps Design Criteria Equipment Units Specifications Steam Surface Condenser Number No. 1 Type Water Cooled Temperature of Condensate oF 125 Operating Pressure in Hga 4 Cooling Water Recirculated Potable Water Cooling Water Supply Temperature oF 85 Cooling Water Return Temperature oF 105 Condensate Pumps Number No. 2 (1 Duty, 1 Standby) Type Vertical Multistage Centrifugal Design Flow Rate gpm 100 Approximate Head ft 60 Approximate Motor size hp 4 Drive Constant Speed (8) Cooling Water Heat Exchangers - R-1-B A once-through cooling system, consisting of heat exchangers and pumps, will provide cooling water to the steam condensers. Plant effluent water (PEW) will be used as the coolant. A BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 27 portion of the heated PEW exiting the cooling water heat exchangers will be used in the incinerator wet scrubber system impingement trays. Preliminary equipment design information for the cooling heat exchanger is shown in Table 6- 16. Table 6-16 Cooling Water Heat Exchanger Design Criteria Equipment Units Specifications Cooling Water Heat Exchangers Number No. 2 (1 Duty + 1 Standby) Type Plate and frame Cooling Fluid Type PEW Approximate Flow gpm 5,000 Design Pressure Drop psi 10 Design Inlet Temperature oF 80 Design Outlet Temperature oF 100 Cooled Fluid Type Recirculated potable water Approximate Flow gpm 4,900 Design Pressure Drop psi 10 Design Inlet Temperature oF 105 Outlet Temperature oF 85 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 28 (9) Condensate Handling System - R-1-B A condensate handling system consisting of deaerators, condensate storage tank, and waste heat boiler feed water pumps will be provided to condition, store and pump condensate in the closed- loop waste heat boiler steam system. Preliminary equipment design information for the condensate handling system is listed in Table 6-17. Table 6-17 Condensate Handling System Design Criteria Equipment Units Specifications Condensate Storage Tank Number No. 1 Type Vertical, Carbon Steel. Capacity min 30 Capacity gal 3,000 Deaerator Number No. 1 Type Tray Type Condensate flow rate pph 50,000 Steam Flow pph 4,000 Sump Storage 10 minutes Waste Heat Boiler Feed Pumps Number No. 2 (1 Duty, 1 Standby) Type Centrifugal Design flow rate gpm 100 Approximate head ft 1,200 Approximate motor size hp 100 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 29 (10) Water Treatment System - R-1-B A package type water treatment system will be provided to treat potable water for boiler water make up. The water treatment equipment will depend on the potable water quality and make up water quality requirements. The water treatment system will consist of cartridge filters, carbon filters, water softeners, reverse osmosis (RO), demineralizers, demineralized water storage tank, and make up water pumps. The water treatment systems will include standby components to support 7 day, 24 hour incinerator operation during water system equipment cleaning and regeneration. The water softening and the demineralizer systems will require periodic regeneration; the RO system will require a periodic clean-in-place (CIP). All regeneration and CIP is expected to be performed off-site through a service contract. Preliminary equipment design information for the packaged water system is shown in Table 6- 18. Table 6-18 Packaged Water Treatment Design Criteria Equipment Units Specifications Packaged Water Treatment Number No. 2 (1 Duty, 1 Standby) Required Treated Water Flow Rate gpm 50 Design Pressure Loss As Required by Vendor Make Up Water Tank Capacity gal 6,000 d. Future Advanced Air Pollution Control - R-1-C Regulations associated with mercury discharge from sludge incinerators are anticipated to change in the next five to ten years. Regulatory restrictions are currently being imposed on plants in the Northeast United States and may be adopted throughout the country. The regulation modifications are expected to require the addition of an advanced air pollution control system for mercury removal from incinerator exhaust gases. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 30 Mercury differs from other metals in the incineration process. Metals in the incinerator feed solids typically are removed from the process entrained in the ash or through the wet scrubber. While some mercury becomes entrained in the ash or is collected in the wet scrubber, the remainder is volatilized as elemental mercury (Hg0) in the incinerator. As the gaseous elemental mercury is cooled through the remaining processes, it can react with other components of the flue gas to form oxidized gaseous mercury (Hg2+). The components can be halogens (chlorine, fluorine, and bromine) or oxides of sulfur, such as sulfur dioxide (SO2) and sulfur trioxide (SO3) or nitrogen, such as nitrogen dioxide (NO2). Little mercury is typically retained in the ash. A fraction of the oxidized mercury (Hg2+) is soluble in water and is captured in the wet scrubbing process. The elemental species, which has low solubility in water and is emitted from the stack, must be oxidized and removed through scrubbing. The exhaust gases from the secondary heat exchanger will be directed to the advanced air pollution control system. Air pollution control equipment for mercury removal includes an exhaust gas conditioning tower, carbon injection tower, carbon storage, fabric filter (followed by previously described wet scrubber), dry ash system, and ID fan. Figure 6-6 shows the main mercury scrubbing process using carbon injection and a fabric filter. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 31 Figure 6-6 Advanced Air Pollution Control System w/ Mercury Scrubbing Mercury removal may also be accomplished by fixed bed carbon scrubbers. Comparison of the different mercury scrubbing options was not included for this evaluation, but it is recommended prior to final system selection. Descriptions of the various advanced air pollution control equipment required for a carbon injection system are included below. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 32 (1) Conditioning Tower - R-1-C The exhaust gases leaving the secondary heat exchanger will be directed to the gas conditioning tower, where it will be cooled adiabatically using a small amount of atomized PEW. The conditioning tower system includes the gas conditioning vessel, atomized water-air spray lances, water booster pumps and air compressors. Preliminary equipment design information for the conditioning tower system is listed in Table 6-19. Table 6-19 Gas Conditioning Equipment Design Criteria Equipment Units Specifications Gas Conditioning Equipment Number of Conditioning Towers No. 3 Vessel Dimensions Diameter ft 12 Height ft 45 Design temperatures Exhaust gas inlet (normal operation)1 oF 1,050 Exhaust gas inlet (from bypass) oF 1,200 Exhaust gas inlet (from SHE with heat recovery option) oF 400 Exhaust gas out oF 300 Quench water flow – (high temperature inlet condition) gpm 40 to 50 Quench water flow – (low temperature inlet condition) gpm 10 to 20 Water design pressure psig 60 Number of Air Compressors (per tower) No. 2 (1 duty, 1 standby) Compressor Dimensions Length ft 10 Width ft 6.5 Compressor Motor hp 150 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 33 1 Normal operation defined as no power generation. (2) Carbon Injection and Storage - R-1-C Carbon will be injected upstream from the fabric filter for mercury removal. The mercury will adsorb onto the carbon and more than 90 percent of the mercury will be removed by the fabric filters. The removed mercury/carbon solids will be handled through the ash handling process. The carbon system will include powdered activated carbon storage silos, volumetric feeders, carbon conveyance blowers and carbon injection assemblies. Powdered activated carbon will be delivered to the site by truck and stored in a carbon storage silo. Conveyance blowers will deliver the carbon from the carbon storage silo to the exhaust gas stream feed point ahead of the fabric filter. Preliminary equipment design information for the carbon system is shown in Table 6-20. Table 6-20 Carbon System Design Criteria Equipment Units Specifications Carbon System Number of carbon storage silos No. 2 Type Vertical with conical base Volume1 (each) Storage cf days 860 30 Size Diameter ft 12 Total Height2 ft 45 Number of carbon volumetric feeders 2 per silo Feed rate pph 30 Number of carbon conveyance blowers 2 per silo Flow (each) scfm 100 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 34 1 Carbon storage based on incinerator capacity for two units in operation. 2 Silo height includes clearances for transport and dust collection equipment. (3) Fabric Filters - R-1-C The carbon solids will form a layer on the surface of the fabric filter bags, which will act as a mercury adsorption layer. Periodic, automatic filter cleaning will be performed using compressed air. The mercury-laden carbon and other particulate matter will be collected at the bottom of each fabric filter as dry ash. The dry ash will be collected by a screw conveyor at the base of each fabric filter and pneumatically conveyed to ash storage silos. Preliminary equipment design information for the fabric filters is shown in Table 6-21. Table 6-21 Fabric Filter Design Criteria Equipment Units Specifications Carbon System Number of fabric filters No. 3 Type Multi-Chamber Dimensions Length Width Height ft 42 14 55 Exhaust Flow Temperature Volume1 oF acfm 350 max 45,000 No. of ash collection screw conveyors No. 3 (2 Duty, 1 Standby) Capacity (each)2 lb/min 67 Motor hp 25 1 Fabric filter exhaust flow rate capacity based on incinerator capacity at high volatile (70% VS) conditions. 2 Ash conveyor capacity rate based on incinerator capacity and low volatile (60% VS) condition. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 35 (4) Dry Ash System - R-1-C The dry ash collected at the fabric filters will be transported to dry ash storage silos by dense phase pneumatic conveyance systems consisting of ash surge hoppers, pneumatic transporters, compressors and conveyance piping. The dry ash will be stored in storage silos to be hauled off site for disposal. Preliminary equipment design information for the dry ash system is shown in Table 6-22 Table 6-22 Dry Ash System Design Criteria Equipment Units Specifications Dry Ash System Number of surge hoppers1 No. 3 Type Dry ash surge hopper capacity cf Vertical with Conical Base 10 Number of pneumatic transporters1 No. 3 Type Air flow Operating pressure scfm psig Dense Phase, Conical Base 100 100 Number of compressors No. 2 (one duty, one standby) Type Compressor capacity Compressor motor scfm hp Scroll or Screw Type 100 25 Number of storage silos No. 3 Type Vertical with Conical Base Volume (each)2 Storage (AA conditions) cy days 630 7 Dimensions Diameter Total Height3 ft 24 75 1 Ash surge hopper and transporter vessel located under each fabric filter ash conveyor. Transport system based on incinerator capacity and low volatile (60% VS) condition. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 36 2 Ash storage based on low volatile (60% VS) and AA solids feed rate conditions for two incinerators. 3 Silo height includes clearances for nozzle, ash unloading equipment and truck. (5) Induced Draft Fans - R-1-C ID fans will provide additional energy to convey exhaust gases from the wet scrubber through the air pollution control equipment and discharge to the stack. Preliminary equipment design information for the ID Fan is shown in Table 6-23. Table 6-23 Induced Draft Fan Design Criteria Equipment Units Specifications ID Fan Number of Units No. 3 Type Single-Stage Centrifugal, Direct Drive Air Flow1 scfm 35,700 Flow Adjustment Inlet damper Pressure Rise in w.c. 40 Motor hp 400 Special Construction/Materials --- 316 SS wheels and shafts 1 Fan capacity based on incinerator capacity and high volatile (70% VS) condition. 5. Layout Plans Refer to Figures C-1 through C-5 in Appendix C for preliminary layouts of the new Solids Processing Building which includes the new FBIs, wet scrubbers and auxiliary systems. 6. Site Plan Refer to Figure A-1 in Appendix A for a preliminary site plan showing the proposed location of the new Solids Processing Building. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 37 7. Staffing Requirements Table 6-24lists the anticipated staffing requirements for each of the proposed alternatives. Table 6-24 Staffing Requirements Type Value Number Hr/Shift Shift/day Day/Wk Wk/Yr Total hrs R-1 - New FBIs and Centrifuges Supervisor 3 8 1 7 52 8,736 Operator 4 8 3 7 52 34,944 Maintenance 3 8 3 5 52 18,720 R-1-A Option – Steam Generation Operator -- -- -- -- -- -- Maintenance 0.5 8 1 5 52 1,040 Stationary1 Engineer 0.5 8 3 7 52 4,368 R-1-B Option – Power Generation Operator -- -- -- -- -- -- Maintenance 1 8 1 5 52 2,080 Stationary1 Engineer 1 8 3 7 52 8,736 R-1-C Option – Future Air Pollution Control Operator 0.5 8 3 7 52 4,368 Maintenance 1 8 1 5 52 2,080 1 Licensed steam boiler engineer/operator. 8. Cost Summary Table 6-25presents the Engineer’s Opinions of Costs for construction costs, annual operation and maintenance costs, annual savings with biosolids use, and life cycle costs. These costs were determined based on the descriptions of alternatives and options presented here. These costs and BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 38 benefits were developed and presented in Technical Memorandum No.9 Opinions of Costs for Alternatives. All costs and savings are in 2010 dollars. Table 6-25 Costs Summary of Regional Facility ($1000) Alternative R-1 FBI +CFG R-1-A FBI + Steam R-1-B FBI + Power R-1-C FBI + AEC Capital Costs Salvage Value $206,559 ($5,563) $20,603 ($1,106) $41,215 ($791) $37,873 ($1,513) Annual O&M Costs $13,648 $502 $864 $35 Annual Revenue ($0) ($1,898) ($1,136) ($0) Present Worth Costs Capital $206,559 $20,603 $41,215 $37,873 Salvage ($2,096) ($417) ($298) ($570) O&M $170,087 $6,256 $10,767 $433 Revenue ($0) ($23,658) ($14,153) ($0) Total Present Worth Costs $374,550 $2,784 $37,531 $37,736 9. Total System Regionalization of biosolids treatment is one means of taking advantage of the economy of scale. In addition to helping reduce overall capital expenditures, operations and maintenance costs can be reduced through economies in staffing. Rather than implement biosolids processing facilities at individuals plants, it may make more economic sense for MSD to consider implementing a regional biosolids processing facility at Bissell Point WWTP, which is the largest of all the WWTPs operated by MSD. Under the regional biosolids management scheme, the solids generated at Lemay, Coldwater, Missouri River, and Lower Meramec will be transported to Bissell Point for processing. The BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 39 following sections describe the regional system alternatives developed for evaluation and the process modifications required at the individual plants for implementing the regional system. a. Decentralized Treatment of Solids (Alternative S-1 No Regional Facility). The decentralized solids treatment alternatives for the WWTPs involve treatment and disposition of solids at the individual plants. Details of sludge treatment processes and equipment sizing for the decentralized options can be found in the Solids Processing Alternative Evaluation Technical Memorandums No. 1 through No. 6 for each treatment facility. To compare the overall economics of decentralized treatment with a regional system, base case solids treatment schemes were identified for the individual plants from the range of biosolids treatment options evaluated. Landfilling of dewatered cake or ash was used as the default disposal method for all base case option. Table 6-26summarizes the base case options considered for the individual plants. Table 6-26 Base Case Solids Treatment Schemes for Individual Plants Plant Treatment Alternative Bissell Point WWTP B-2: FBI + CFG Lemay WWTP . Solids processing includes co-thickening, centrifuge dewatering, and fluidized bed incineration. Landfill disposal of incinerator ash. No energy recovery as steam or power. L-3: FBI + CFG Coldwater WWTP . Solids processing includes co-thickening, centrifuge dewatering, and fluidized bed incineration. Landfill disposal of incinerator ash. No energy recovery as steam or power. C-1: Current Operation Missouri River WWTP . No solids processing at Coldwater. Thickened solids will be pumped to the Bissell watershed for processing at the Bissell Point WWTP. M-1: Current Operation Lower Meramec WWTP . No new solids processing facilities. All solids processing improvements included with the Secondary Treatment Expansion and Disinfection Facilities and the Digester Rehabilitation projects are considered existing. Additional cogeneration capacity required at projected design year digester loadings is included. LM-1: Co-thickening + AD. Solids processing involves re-use of existing gravity thickeners for PS and WAS co-thickening followed BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 40 by new anaerobic digesters for solids stabilization, and use of digester gas for cogeneration. Dewatering facilities are not included since dewatering was not evaluated as part of Phase II evaluations. A flow chart of the solids processes at each plant for the Decentralized (No Regional) Treatment Alternative S-1 is shown on Figure 6-7. Coldwater Thickening Gravity Thickening(New EQ) Force Main to Regional Facility (New PS & FM) Lower Meramec Thickening Gravity Thickening (New EQ & Tank) Dewatering1 BFP Cake Storage and Loadout to Disposal1 (New Extra Capacity) Lemay Thickening Gravity Thickening GBT Dewatering Centrifuge(New) Bissell Point Thickening Gravity ThickeningGBT Dewatering Centrifuge(New) Incineration FBI (New) Ash Dewatering (Ash Lagoon, upgrade to slurry system) Ash Loadout MSD Decentralized Treatment System (S-1) Solids Handling Process Flow Chart MO River Thickening RDT Thickening(New EQ) Anaerobic Digestion Dewatering Centrifuge Cake Storage and Loadout to Disposal CHP (New EQ) End Use End Use Incineration FBI (New) Ash Dewatering (Ash Lagoon, upgrade to slurry system) End Use EndUse Ash Loadout Anaerobic Digestion (New) CHP (New) Note 1Additional equipment needed but not included in the cost evaluation. Figure 6-7. Solids Process Flow Chart for Decentralized (No Regional) Treatment S-1 b. Regional Treatment of Solids. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 41 If the regional biosolids treatment facility is implemented at the Bissell Point WWTP, solids from the other MSD plants would either be hauled or pumped to the regional facility for incineration. Since digesting the solids upstream from incineration lowers the calorific value of the feed solids and may require auxiliary fuel for incineration, the regional system is based on discontinuing or not implementing anaerobic digestion at Missouri River and Lower Meramec WWTPs. Anaerobic digestion was considered for the decentralized option to provide added flexibility for biosolids end use and to increase the potential for energy recovery in the form of digester gas at the county plants. Two variations of the regional system were considered for evaluation. (1) Alternative S-2 Lemay Hauling The Total System Alternative S-2 is based on hauling dewatered solids from Lemay, Coldwater, Lower Meramec, and Missouri River WWTPs to the regional facility. The solids generated at the Bissell Point WWTP (including Coldwater solids) will be pumped to a new dewatering building adjacent to the new solids processing building for dewatering and further processing at the regional facility. The modifications required to the base case solids treatment alternatives at the individual plants for implementing the regional Total System S-2 processing scheme are summarized in Table 6-27. Table 6-27 Modifications Required to the Base Case Treatment Options at Individual Plants for Implementing the Regional Total System S-2 Base Case (No Regional) S-1 Alternative S-2 Lemay Hauling Bissell Point WWTP B-2: FBI + CFG. Co-thickening, centrifuge dewatering, and fluidized bed incineration. Landfill disposal of incinerator ash. R-1 Lemay WWTP . Regional Facility located at Bissell Point. The solids generated at Bissell Point (including Coldwater solids) will be dewatered using new centrifuges and pumped to the regional plant for incineration using new FBIs. Landfill disposal of ash. No energy recovery as steam or power. L-3: FBI + CFG. Co-thickening, centrifuge dewatering, and fluidized bed incineration. Landfill disposal of incinerator ash. Modified L-3. Solids processing includes co-thickening, and centrifuge dewatering. Dewatered solids will be hauled to the regional BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 42 Table 6-27 Modifications Required to the Base Case Treatment Options at Individual Plants for Implementing the Regional Total System S-2 Base Case (No Regional) S-1 Alternative S-2 Lemay Hauling facility. Incinerators and ash treatment system not required at plant. Coldwater WWTP C-1: Current Operation. Thickened solids pumped to the Bissell watershed for processing at the Bissell Point WWTP. C-1 Missouri River WWTP . No change from the decentralized base case option. Thickened solids will be pumped to Bissell Point for treatment. M-1: Current Operation. No new solids processing facilities. Additional cogeneration capacity included. Modified M-1 Lower Meramec WWTP . Existing anaerobic digestion, digester gas cleaning, and cogeneration will be decommissioned. Thickened PS and WAS will be a dewatered using existing centrifuge and dewatered solids hauled to the regional facility. LM-1: Co-thickening + AD. Co-thickening of PS and WAS in gravity thickeners and anaerobic digestion Dewatering facilities not included. Modified LM-1 A flow chart of the solids processes at each plant for the Total System Alternative S-2 is shown on . Co-thickened solids will be dewatered using existing BFPs and hauled to the regional facility. Anaerobic digestion, gas cleaning and cogeneration facilities will not be required. Figure 6-8. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 43 Coldwater Thickening Gravity Thickening Force Main to Regional Facility (New PS & FM) MO River Thickening RDT Thickening Dewatering Centrifuge Cake Storage and Loadout to RegionalFacility Lower Meramec Thickening Gravity Thickening (New EQ & Tanks) Dewatering1 BFP(New Add.EQ) Cake Storage and Loadout to RegionalFacility1 Lemay Thickening Gravity Thickening GBT Dewatering Centrifuge (New) Cake Storage and Loadout to Regional Facility Bissell Point Thickening Gravity Thickening GBT Dewatering Centrifuge (New) DewateredSludge Receiving (New)Incineration FBI (New) Regional Facility Ash Dewatering (New) Ash Loaddout MSD Regional System (S-2) Solids Treatment Process Flow Chart -Hauling Cake from Lemay Note 1Additional equipment needed but not included in the cost evaluation. Figure 6-8 Solids Process Flow Chart for Alternative S-2 Lemay Hauling (2) Alternative S-3 Lemay Pump Station The only variation from Alternative S-2 is the means of transport of solids from Lemay to the regional facility. For Alternative S-3, thickened solids from Lemay will be pumped to Bissell for dewatering and incineration at the Regional Facility. Dewatering facilities will not be required at the Lemay WWTP. A new pump station and force main will be provided to transfer co-thickened PS and WAS to the regional facility. The BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 44 additional pumping and dewatering capacity requirements at Bissell for receiving liquid sludge from Lemay were not evaluated in detail for the regional option. The dewatering facility costs at Lemay for the base case alternative were added to the regional facility costs to account for the additional capacity requirements. The solids processing requirements at all the other WWTPs are identical to Alternative S-2. A flow chart of the solids processes at each plant for the Alternative S-3 is shown on Figure 6-9. Coldwater Thickening Gravity Force Main to Regional Facility (New PS & FM) MO River Thickening RDT Thickening Dewatering Centrifuge Cake Storage and Loadout to Regional Facility Lower Meramec Thickening Gravity Thickening(New EQ & Tanks) Dewatering1 BFP (New Add.EQ) Cake Storage and Loadout to Regional Facility1 Lemay Thickening Gravity ThickeningGBT Bissell Point Thickening Gravity ThickeningGBT Dewatering Centrifuge (New) DewateredSludge Receiving (New)Incineration FBI (New) Regional Facility Ash Dewatering (New) Ash Loaddout MSD Regional System (S-3) Solids Treatment Process Flow Chart -Pumping Sludge from Lemay Force Main to Regional Facility (New PS & FM) Note 1Additional equipment needed but not included in the cost evaluation. Figure 6-9. Solids Process Flow Chart for Alternative S-3 Lemay Pump Station BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 45 c. Cost Summary A comparison of Engineer’s Opinions of Costs for the No Regional Alternative S-1 and the Total System Alternatives S-2 and S-3 are presented in Table 6-28. The costs include construction costs, annual operation and maintenance costs, annual savings with biosolids use, and life cycle costs for the two options. Detailed cost information for this comparison is presented in Technical Memorandum No.9 Opinions of Costs for Alternatives. Table 6-28 Total System Costs Summary ($1000) Option S-1 No Regional S-2 Lemay Hauling S-3 Lemay Pump Station Capital Costs $324,923 $243,653 $276,608 Salvage Value ($12,208) ($7,832) ($11,781) Annual O&M Costs $16,960 $19,839 19,269 Annual Revenue ($807) ($0) ($0) Present Worth Costs Capital $324,923 $243,653 $276,608 Salvage ($4,601) ($2,952) ($4,440) O&M $211,359 $247,238 $240,134 Revenue ($10,057) ($0) ($0) Total Present Worth Costs $521,624 $487,939 $512,302 An evaluation of the alternatives presented here are included in TM 10 – Alternatives Selection Processes and Results. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 46 Appendix A Site Plans BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 47 Appendix B Detailed Process Flow Schematics BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Regional Facility Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 48 Appendix C Layouts Plans Appendix D – Solids Handling MP TM-1 (Sub-Regional Bissell) BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 1 TECHNICAL MEMORANDUM NO. 1 – BISSELL POINT WWTP SOLIDS PROCESSING ALTERNATIVES EVALUATION To: Metropolitan St. Louis Sewer DistrictFrom: Jim Rowan, Gustavo Queiroz, Patricia Scanlan, Hari Santha This Technical Memorandum presents information on the solids processing and management alternatives evaluated for the Bissell Point Wastewater Treatment Plant (WWTP) as part of developing a strategic plan for long-term management of biosolids. Information on the existing facilities for the planning effort was obtained from existing plant records, interviews with MSD staff, and plant permits. The following sections describe the existing biosolids management system, the solids quantities used as the basis for the evaluation, and the treatment options evaluated for Bissell Point. Table of Contents 1. Existing Plant Information............................................................................................3 2. Solids Quantities...........................................................................................................7 3. Solids Processing Alternatives......................................................................................9 a. Alternative B-1 – Re-use of MHIs and BFPs......................................................... 9 b. Alternative B-2 – New FBI and Centrifuges........................................................ 10 4. Technologies for Solids Processing Alternatives .......................................................12 a. Solids Thickening................................................................................................. 12 b. Sludge Wells......................................................................................................... 13 c. Dewatering............................................................................................................ 13 (1) Alternative B-1 – Existing Belt Filter Press Dewatering............................ 13 (2) Alternative B-2 – New Centrifuge Dewatering.......................................... 14 d. Cake Conveyance and Storage ............................................................................. 15 (1) Alternative B-1 - Existing Cake Conveyance and Storage System............ 15 (2) Alternative B-2 - New Cake Conveyance and Storage System.................. 17 e. Incinerator Systems............................................................................................... 19 (1) Alternative B-1 - Existing Multiple Hearth Incinerator Systems ............... 21 (2) Alternative B-1 - Air Pollution Control...................................................... 23 (3) Alternative B-1 – Induced Draft (ID) Fans................................................. 25 (4) Alternative B-1 – Ash Handling System .................................................... 25 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 2 (5) Alternative B-2 - Fluidized Bed Incinerator System.................................. 27 (6) Alternative B-2 - Primary and Secondary Heat Exchangers ...................... 29 (7) Alternative B-2 – Air Pollution Control Equipment................................... 30 (8) Alternative B-2 – Ash Handling System .................................................... 32 (9) Alternative B-2 - Fluidizing Air Blower..................................................... 33 (10) Alternative B-2 - Fuel Storage Tank and Pumps .................................... 33 (11) Alternative B-2 - Sand System................................................................ 35 (12) Alternative B-2 - Energy Recovery Options........................................... 36 (13) Steam Generation – Steam Sale to Trigen Option B-2-A....................... 36 (14) Waste Heat Boilers – B-2-A ................................................................... 37 (15) Water Treatment System – B-2-A........................................................... 39 (16) Power Generation Option – B-2-B.......................................................... 40 (17) Waste Heat Boilers – B-2-B.................................................................... 41 (18) Steam Turbine Generator – B-2-B.......................................................... 43 (19) Steam Condenser – B-2-B....................................................................... 44 (20) Cooling Water Heat Exchangers – B-2-B............................................... 45 (21) Condensate Handling System – B-2-B.................................................... 46 (22) Water Treatment System – B-2-B........................................................... 47 (23) Future Advanced Air Pollution Control – B-2-C.................................... 47 (24) Conditioning Tower – B-2-C.................................................................. 49 (25) Carbon Injection and Storage – B-2-C.................................................... 51 (26) Fabric Filters – B-2-C ............................................................................. 52 (27) Dry Ash System – B-2-C ........................................................................ 53 (28) Induced Draft Fans – B-2-C.................................................................... 54 5. Alternative B-1 – Layout Plans....................................................................................54 6. Alternative B-2 – Layout Plans....................................................................................54 7. Site Plan.......................................................................................................................55 8. Staffing Requirements .................................................................................................55 9. Cost Summary..............................................................................................................56 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 3 1. Existing Plant Information The Bissell Point WWTP was commissioned in 1970 with a permitted design flow of 250 mgd. The plant has both trickling filters and activated sludge for secondary treatment. However, the activated sludge system is currently not in use. A site plan of Bissell Point WWTP is shown on Figure 1-1. Figure 1-1. Bissell Point WWTP Site Plan The WWTP generates primary solids (PS) and tricking filter solids (TFS), which are co- thickened in primary clarifiers to approximately 3 percent total solids (TS). The Bissell watershed also receives thickened undigested solids pumped into the collection system from the Coldwater WWTP. Grease wastes are trucked to the WWTP and unloaded via manholes upstream from the pre-aeration tanks. Grease and scum are collected from the BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 4 primary clarifiers, pumped to scum thickeners and then conveyed to two sludge wells by progressing cavity pumps where they are combined with the co-thickened sludge pumped from the primary clarifiers. The combined solids are dewatered to approximately 30 percent TS using fifteen belt filter presses (BFP). Polymer is added to the sludge at a rate of approximately 10 lb of active polymer per dry ton of solids (lb/dt). Bottom sludge from the scum concentrators and filtrate from the BFPs are combined in the Dewatering Building Drainage Well and returned to the primary clarifiers. The dewatered cake from the BFPs is discharged to belt conveyors, which convey it to six equalization bins. Hydraulic piston pumps are used to feed the dewatered cake from the equalization bins to six multiple hearth incinerators (MHIs). The MHIs thermally oxidize the dewatered cake to produce ash and exhaust gases. The exhaust gases from the incinerators are treated using wet scrubbers and the ash is sluiced and pumped to two ash lagoons located on site. A schematic of the existing solids treatment processes is presented in Figure 1-2. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 5 Figure 1-2. Existing Solids Processes at Bissell Point WWTP The specifications of the existing solids processing facilities at the WWTP are summarized in Table 1. Table 1-1. Rated Capacities of Existing Solids Processing Facilities Equipment Units Value WASTE ACTIVATED SLUDGE THICKENING (NOT IN USE) Gravity Belt Thickeners (GBT) Number of GBTs No.12 Belt Width m 2 Hydraulic Capacity gpm/m 220 SOLIDS DEWATERING Belt Filter Presses (BFP) Number of BFPs No.15 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 6 Table 1-1. Rated Capacities of Existing Solids Processing Facilities Equipment Units Value Belt Width m 2 Hydraulic Capacity gpm/m 125 INCINERATION Multiple Hearth Incinerators (MHI) Number of MHIs No.6 Capacity dtpd 60 Pictures of the existing solids processing facilities are shown in Figure 1-3. Gravity Belt Thickeners Incinerator Feed Pumps BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 7 Belt Filter Presses Multiple Hearth Incinerators Figure 1-3. Existing Solids Processing Facilities at the Bissell Point WWTP 2. Solids Quantities The Bissell Point WWTP serves a mature watershed with little flow increase expected in the future. The solids quantities used for this evaluation were developed based on implementing biological nutrient removal (BNR) in the future. The primary process modification for BNR will include re-commissioning the activated sludge process, resulting in the generation of a waste activated sludge (WAS) stream. The WAS quantities with BNR were estimated using process models, which are summarized in the BNR Basin Sizing and Estimation of Waste Activated Sludge Production Report (Appendix B). The PS quantities were based on historical plant data. A summary of the solids quantities from the model is presented in Table 1-2. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 8 Table 1-2. Projected Solids Quantities1 Parameter Units Max. Month Ann. Avg. Primary Sludge Total Solids dtpd 75.0 62.0 Volatile Solids Fraction % of TS 59 59 Volatile solids dtpd 44.3 36.6 Waste Activated Sludge Total Solids dtpd 48.0 24.5 Volatile Solids Fraction % of TS 55 55 Volatile solids dtpd 26.4 13.5 Total Solids Total Solids2 dtpd 125.7 89.1 Volatile Solids Fraction % of TS 58.0 58.2 Volatile solids dtpd 73.0 51.9 Solids Concentration %1.5 1.5 Flow gpd 1,997,480 1,413,380 1 Solids quantities listed include thickened undigested sludge from Coldwater WWTP. Solids quantities are based on historical plant data for year 2009 only. Modeling including additional years of historical plant data is recommended prior to detailed design. 2 Total solids include grease wastes. Solids modeling results based on existing plant data projected lower than typical volatile solids (VS) concentrations in PS and WAS. The lower VS concentration may be attributed to the higher fraction of inorganics in the plant influent during high flows. The maximum month (MM) quantities were used as the basis for equipment sizing at Bissell Point. The mid-point (10-year) annual average quantities were used as the basis for determining the operations and maintenance (O&M) costs for the evaluation. The BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 9 mid-point average solids quantities are identical to the future annual average solids production since the Bissell watershed is mature with minimum future growth. The other assumptions made in developing the solids quantities for the process evaluations are summarized below. ƒCo-thickened solids (PS + WAS) concentration of 1.5 percent from primary clarifiers. ƒSolids capture efficiency of 98 percent in BFP dewatering units. ƒSolids capture efficiency of 98 percent in Centrifuge dewatering units. ƒDewatered cake solids concentration of 30 percent from belt filter presses and 35 percent from centrifuges. ƒVolume calculations for cake storage and conveyance equipment based on 30 percent TS. 3. Solids Processing AlternativesBased on discussions with the District staff and site visits to the Bissell Point WWTP, two alternatives were developed for processing and management of biosolids generated at the Bissell Point WWTP. Descriptions of the alternatives are presented in the following sections. Refer to Appendix C of this report for detailed process flow diagrams for all alternatives. a. Alternative B-1 – Re-use of MHIs and BFPs This alternative is the base-case scenario and will include re-use of the existing cake receiving and handling equipment, belt filter presses (BFPs), multiple hearth incinerators (MHIs), ash handling, and air pollution control systems (APCs). Modifications and upgrades to the existing systems will be required and are discussed later in this report. Figure 1-4 illustrates the overall process flow diagram for Alternative B-1. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 10 Figure 1-4: Solids Flow Diagram - Alternative B-1 b. Alternative B-2 – New FBI and Centrifuges This alternative will consist of new solids processing facilities including cake receiving and handling facilities, dewatering centrifuges, incinerator feed pumps, fluidized bed incinerators (FBIs), air pollution control systems and heat recovery. The air pollution control system evaluation will include options for mercury removal and dry ash handling. The heat recovery evaluation will include steam generation with sale to a local utility provider, Trigen, and power generation to reduce plant electricity purchased from the electrical utility serving the plant. Based on the larger size for the new fluidized bed incinerators and preliminary assessment of the existing incinerator building, it was determined that the current available space is not sufficient to house the new larger fluidized bed incinerators and associated equipment. In addition, the construction of a new solids processing facility BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 11 will provide additional flexibility allowing the existing solids processing system to remain in operation during construction phase of the new facility. Figure 1-5 illustrates the overall process flow diagram for Alternative B-2. Figure 1-5: Solids Flow Diagram - Alternative B-2 – New FBIs A summary of the new and existing equipment being evaluated for each alternative is presented in Table 1-3. Table 1-3. Solids Processing Alternatives Equipment Alternative B-1 Re-use MHIs Alternative B-2 New FBIs Cake Receiving and Handling E N Dewatering Belt Filter Presses E --- Dewatering Centrifuges ---N Dewatered Cake Equalization Bins E N BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 12 Table 1-3. Solids Processing Alternatives Equipment Alternative B-1 Re-use MHIs Alternative B-2 New FBIs Incinerator Cake Feed Pumps E N Multiple Hearth Incinerators E --- Fluidized Bed Incinerators ---N Air Pollution Control (Wet Scrubber)E N Advanced Air Pollution Control (Fine Particulate and Mercury Removal)--- N Dry Ash Handling ---N Legend E = Existing system will be evaluated and modifications/upgrades recommended. : N = The implementation of a new system will be evaluated. 4. Technologies for Solids Processing Alternatives The solids processing technologies considered to support the two alternatives are briefly discussed in the following sections. a. Solids Thickening The existing primary clarifiers will be used to co-thicken PS and WAS to approximately 1.5 percent TS. Since solids production is not expected to increase during the planning period, no additional thickening capacity will be required in the future. It is important to note that the future conversion from trickling filters (TFs) to a BNR system with phosphorous removal will preclude the use of the primary clarifiers for co- thickening PS and WAS. Co-thickening PS and WAS has the potential to create anaerobic conditions and re-release phosphorous in the primary clarifiers, reducing the overall phosphorous removal efficiency. In the future, if biological phosphorous removal is incorporated, it is recommended that WAS be thickened separately using the existing gravity belt thickeners (GBTs) or other mechanical thickening technologies. WAS BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 13 thickening technologies are not evaluated as part of this report. The existing GBTs have adequate capacity to handle the projected WAS quantities as indicated in Table 1-4. Table 1-4. Existing GBT Loading at Projected Loads Design Conditions Units Max. Month Ann. Avg. Operating Schedule h/d 24/7 24/7 Number of Operating Units No.42 Rated Hydraulic Capacity gpm/m 220 220 Hydraulic Loading Rate gpm/m 200 204 Expected Solids Concentration %55 b. Sludge Wells The existing sludge wells are expected to have sufficient capacity to process future solids and are not evaluated for this report. c. Dewatering (1) Alternative B-1 – Existing Belt Filter Press Dewatering The existing BFPs were evaluated as part of Alternative B-1 to dewater the combined PS and future WAS. Typically, trickling filter solids has a higher fraction of inorganics and dewaters better than WAS. Consequently, when the activated sludge process is brought online in the future, the throughput for the dewatering units may be lower than the current loadings with trickling filters. According to the projected solids production in Table 2, the existing dewatering BFPs and the BFP feed pumps are expected to have adequate capacity to process future solids quantities. However, based on age and expected life of the existing equipment, the dewatering equipment will need to be replaced or significantly overhauled during the evaluation period. Preliminary equipment design information for dewatering BFPs and BFP feed pumps is listed in Table 1-5. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 14 Table 1-5. BFPs and Feed Pumps Design Criteria Equipment Units Specifications Belt Filter Presses Number of Units1 No.10 (6 duty, 4 standby) Operation Schedule h/d/wk 24/7/52 Belt width m 2 Hydraulic Loading Rate2 gpm/m 125 Solids Loading Rate2 pph/m 940 Solids capture rate %98 Feed Solids %1.5 Cake Solids %30 Polymer use (active)lb/dt solids 10-15 BFP Feed Pumps Number of units No.3 (2 duty, 1 standby) Pump type Centrifugal (Wemco vortex type)3 Required Flow (each)4 gpm 1,100 1 Four (4) BFP units will be required to process solids at AA conditions. A total of six (6) BFP units will be required to process solids at MM conditions.2 Loading rates listed are based on feedback from MSD for current operation.3 Pump selected to match existing BFP feed pumps. 4 Required pump flow rate based on estimated capacity for existing equipment. (2)Alternative B-2 – New Centrifuge Dewatering New centrifuges were evaluated as part of Alternative B-2. For this alternative, the raw co-thickened sludge will be pumped from the existing sludge wells to new centrifuges located in a new solids processing facility. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 15 Preliminary equipment information for the centrifuges and centrifuge feed pumps is listed in Table 1-6 below. Table 1-6. Centrifuge and Centrifuge Feed Pump Design Criteria Equipment Units Specifications Centrifuges Number of Units1 No.6 (5 Duty, 1 Standby) Operation Schedule h/d/wk 24/7/52 Rated Capacity gpm/machine 279 Required Hydraulic Loading Rate2 gpm/machine 277 Required Solids Loading Rate2 pph/machine 2,094 Approximate Diameter in.23 Solids Capture Rate %98 Feed Solids %1.5 Cake Solids %35 Polymer Use (active)lb/dt solids 15-25 Centrifuge Feed Pumps Number of units No.6 (5 Duty, 1 Standby) Pump type3 Centrifugal with AFD (Wemco vortex type) Flow (each)gpm 280 1 Four (4) centrifuges are required to process solids at AA conditions, and Five (5) centrifuges are required to process solids at MM conditions. 2 Required centrifuge loading rates based on MM conditions. 3 Pump type selected to match existing BFP feed pumps. d. Cake Conveyance and Storage (1)Alternative B-1 -Existing Cake Conveyance and Storage System Belt conveyors are used to transfer dewatered cake from the existing BFPs to live-bottom (screw type) equalization bins (see Figure 1-2), which discharge solids to cake pumps BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 16 feeding the incinerators. The capacity of the existing belt conveyors, live-bottom equalization bins and cake pumps will be sufficient for the future solids production. However, based on age and expected life of the existing equipment, they will need to be replaced or significantly overhauled during the evaluation period. The existing cake receiving facility will be upgraded or overhauled to continue receiving cake from other facilities. Preliminary cake conveyance and storage equipment specifications are presented in Table 1-7 below. Table 1-7. Existing Cake Conveyance and Storage Equipment Design Criteria Equipment Units Specifications Dewatered Cake Conveyor System Conveyor type Belt Required capacity1 cf/h 590 Equalization Bins Number of units No.4 (2 Duty, 2 Standby) Type Live bottom (screw) Required volume (each)2 cy 10 Equalization Bins Number of units No.4 (2 Duty, 2 Standby) Type Live bottom (screw) Required volume (each)2 cy 10 Dewatered Cake Pumps Number of units No.4 (2 Duty, 2 Standby) Pump type Hydraulic piston Required flow (each)gpm 35 1 Required capacity based on MM solids condition. 2 Equalization bin sizing based on existing equipment. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 17 (2)Alternative B-2 -New Cake Conveyance and Storage System A new cake conveyance and storage system will be required for Alternative B-2. The system will be located in the new solids processing building. Shafted screw conveyors will be used to transfer dewatered cake from the centrifuges to cake transfer pumps that will feed the equalization bins, as shown on Figure 1-5. Each hopper will be equipped with a sliding frame-type live bottom, which will discharge solids to cake pumps feeding the incinerators. A new cake receiving facility will be required to accept cake hauled from other facilities. The receiving facility will include a cake receiving bin, screw conveyors, storage silos and transfer pumps (Figure 1-5). Preliminary equipment design information for the sludge conveying and storage facilities is listed in Table 1-8. Table 1-8. New Cake Conveying and Storage Equipment Design Criteria Equipment Units Specifications Dewatered Cake Conveyor System Number of units No.2 Conveyor type1 Shafted Screw Required capacity (each)2 cf/h 560 Cake Transfer Pumps (from dewatered cake conveyors to equalization bins) Number of units No.2(1Duty, 1Standby) Pump type Hydraulic piston (Dual Discharge) Required flow (each)gpm 70 Equalization Bins Number of units No.2 Type Live bottom (Sliding Frame) Required volume (each)3 cy 65 Dewatered Cake Pumps (from equalization bin to incinerator) BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 18 Table 1-8. New Cake Conveying and Storage Equipment Design Criteria Equipment Units Specifications Number of units No.4(2Duty, 2Standby) Pump type Hydraulic piston (Dual Discharge) Required flow (each)gpm 70 Dewatered Cake Receiving Bin Number of units No.1 Type Live bottom (screw type) Required volume cy 30 Dewatered Cake Transfer Pumps (from receiving bin to storage silo) Number of units No.2 (1 Duty, 1 Standby) Pump type Hydraulic piston (Dual Discharge) Required flow (each)gpm 100 Dewatered Cake Storage Silo Number of units No.2 Storage days 2 Required volume cy 500 Dewatered Cake Storage Silo Recirculation Pumps 4 Number of units No.4(2Duty, 2Standby) Pump type Hydraulic piston Volume turnover hr 6 Turnover capacity cy/hr 80 Required flow (each)gpm 270 Dewatered Cake Pumps (from storage silo to incinerator) Number of units No.1 Pump type Hydraulic piston (Dual Discharge) Required flow (each)gpm 70 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 19 1 Shafted screw conveyors used for this evaluation. Shaft-less screw type conveyors may be evaluated during detailed design.2 Each cake conveyor system is designed to transfer solids at incinerator capacity.3 Equalization bins sized for approximately 3 hours of storage capacity for each incinerator at 120 dtpd.4 The use of the cake recirculation pump concept for odor reduction will be verified during detailed design. e. Incinerator Systems Incinerator systems combust dewatered cake, converting the organic portion of the feed solids to heat and sterile ash. Descriptions for incinerator system components are presented in the following sections. Many plants currently use multiple hearth incinerators (MHI) to burn dewatered cake generated at their facility. Most of the MHIs were built in the 1970s and 1980s. With over 20 years or more of service they are requiring repairs and upgrades to continue operation. Owners are asking if it is worthwhile to spend the resources to upgrade or replace the units with fluidized bed incinerators (FBI). Table 1-9 presents a discussion of the merits and concerns with upgrading MHIs or replacing them with new FBIs. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 20 Table 1-9. Incinerator Technologies Comparison Item MHI FBI Comment Unit capacity and Sizing 23 ft. diameter MHI will burn 25 to 50 dry tons per day of dewatered sewage solids. The typical FBI will burn 50 to 120 dtpd of solids with most units sized for about 100 dtpd. For every two MHIs, one FBI can match or exceed their capacity, reducing the number of units and space needed. Operation skill and complexity Generally requires one operator per 1 or 2 units to adjust and monitor Typically requires less time with one operator assigned to dewatering and incineration operation. Plant operators, who have experience with both, report that operation of a FBI is less demanding than for a MHI. Cost No new MHIs are being built. Many are undergoing repairs, rebuilding and emissions control upgrades with equipment and installation costs of $2M to $6M per unit. FBIs have equipment and installation costs of $15M to $20M per unit. New FBIs typically require a new building and support facilities, resulting in costs of $30M to $40M for a single unit. For comparison, costs for upgrading MHIs (2 units) would range from $4M to $12M and would provide same or less capacity than one FBI. Emission Controls The MHIs currently use wet scrubbers consisting of a variation of venturis, impingement scrubbers, and wet electrostatic precipitators for particulate and acid gas removal from exhaust gases. CO, THC, and NOx are controlled by operational parameters including temperature and oxygen content. There is no mercury control. FBIs use similar wet scrubbers as MHIs but are inherently better combustion devices with lower emissions of CO, THC, and NOx. Mercury removal has been used for FBIs. New regulations will lower emission limit requirements for both types with the MHIs being impacted the most for CO, NOx and Hg emissions. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 21 Table 1-9. Incinerator Technologies Comparison Item MHI FBI Comment Turndown MHIs will burn under turn down conditions but with some additional fuel usage. FBIs can also be turned down but with much less efficient operation. To accommodate lower feed rates, FBIs are operated in a weekly batch mode where they burn the solids at design rates until the weekly quantity is depleted. Then they are “bottled up” until the cycle repeats. Some auxiliary fuel will be used for warming prior to introducing solids again. Both type incinerators operate more efficiently at design loading. MHIs are more appropriate for small facilities with FBIs used for large facilities. Power generation from incineration Can be implemented to produce electricity with steam/steam turbine. Steam at 400 psia. Can be implemented to produce electricity with steam/steam turbine. Steam at 400psia. Power produced is proportional to the volatile solids burned. For 100 dtpd feed rate, 1 to 1.5 MW produced. Descriptions for each incinerator system alternative can be found in the following sections. (1) Alternative B-1 - Existing Multiple Hearth Incinerator Systems The existing MHIs were evaluated as part of Alternative B-1. For the projected solids quantities in Table 1-2, the existing MHIs are expected to have sufficient capacity to process future solids. However, based on age and expected life of the MHI equipment, the MHIs will need significant rehabilitation during the evaluation period. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 22 Figure 1-6 illustrates the proposed Alternative B-1 MHI incineration system. Figure 1-6: Alternative B-1 – Reuse of MHIs Two incinerators are designed to process the total projected feed solids at annual average conditions. For maximum month conditions, three incinerators will be required to operate. The fourth incinerator will provide spare capacity at maximum month conditions. Preliminary equipment design information for the MHIs is listed in Table 1-10. Table 1-10. Multiple Hearth Incinerators Design Criteria Equipment Units Specifications Multiple Hearth Incinerators Required Number of Units No.4 Operation Schedule h/d/wk 24/7/52 Required Capacity (each)dtpd 60 Incinerator Vessel BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 23 Table 1-10. Multiple Hearth Incinerators Design Criteria Equipment Units Specifications Type No. of Hearths No. Multiple Hearth 11 Size Diameter Height ft ft 23 45 Wall Construction Inner Layer of Walls Outer Layer of Walls Outer Layer of Top Refractory brick Insulated fire brick High duty castible Auxiliary Fuel Source Natural gas Min Natural Gas Pressure psig 10 Discharge Temperature oF 950-1,100 (2)Alternative B-1 -Air Pollution Control To reduce particulate emissions and provide additional operational flexibility for the incinerators, the existing impingement tray scrubbers, induced draft (ID) fans, and associated exhaust ductwork will be replaced. The new scrubbers will re-use the existing scrubber vessels with the current internal components removed. In addition, the upper section of the existing scrubber vessels will be extended to accommodate a new multiple venturi section. A new exhaust gas quench section will be added to pre-condition the exhaust gases before entering the wet scrubber. The new scrubber will be a vertical upflow unit with impingement trays used for cooling and saturating the gas, followed by multiple fixed venturi sections with water injection and mist eliminators with sprays. Plant effluent water will be used for the impingement trays. Strained plant effluent water will be used for the venturi injection and high pressure spray lances. Service water (potable water downstream of a backflow preventer) will be used for the mist eliminator sprays. Booster pumps will be supplied with the scrubbers BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 24 for venturi and high pressure spray lance water injection. Strained plant effluent water is required for the venturi injection and high pressure spray lances to prevent nozzle clogging while potable water is required for the mist eliminator to prevent fouling. Preliminary equipment design information for the wet scrubber and quench section are listed in Table 1-11. Table 1-11. Wet Scrubber and Quench Section Design Criteria Equipment Units Specifications Wet Scrubbers and Quench Station Number of Units No.4 Type Combined impingement tray, and multiple fixed venturis Configuration Vertical, up flow Pressure Drop in w.c.30 Dimensions Diameter Height ft 12 30 Water Requirements (per scrubber) Quench Section Sprays Under Tray Sprays Impingement Trays Venturi Section Sprays Mist Eliminator gpm 100 60 1,200 150 10 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 25 (3)Alternative B-1 – Induced Draft (ID) Fans New ID fans will be required to overcome the increased pressure drop associated with the new wet scrubbers. The ID fans will be located in the same area as the existing fans. The ID fans will pull the clean gas from the air pollution control equipment and discharge it to the stack. Preliminary equipment design information for the ID fans is listed in Table 1-12. Table 1-12. Induced Draft Fan Design Criteria Equipment Units Specifications Induced Draft Fan Number of Units No.4 Type Single stage centrifugal, direct drive Inlet Gas Temperature oF 90-130 Required Capacity acfm 22,000 Flow Adjustment Variable Frequency Drive Pressure Rise (design)in w.c.44 Motor hp 250 Special Construction/Materials 316 SS wheels and shafts (4)Alternative B-1 – Ash Handling System The existing ash handling system collects incinerator bottom ash and combustion air heat exchanger fly ash. The ash is sluiced and pumped to ash lagoons (see Figure 1-1). For MHIs, the majority of the ash (~90 percent) is collected at the bottom of the incinerators while the remaining portion will travel in suspension with the exhaust gases as fly ash. A small fraction of the fly ash drops at the combustion air heat exchanger while the remaining fraction is removed by the wet scrubbers. The existing sluice tank and pumps BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 26 are expected to have sufficient capacity to process future ash quantities. However, MSD has experienced some dust problems with the current ash handling system. To alleviate the dust problem, an ash slurry system including ash slurry pumps and slurry tanks is recommended to replace the existing ash sluice system. The new ash slurry system will use scrubber drain water to mix the ash into a slurry form, which will be pumped to the existing ash lagoons. A new vibrating screen feeder will be installed at the ash discharge of each incinerator to prevent clinkers from entering the ash slurry system and clogging the ash slurry pumps or slurry lines. The new ash slurry system will be capable of processing bottom ash from the incinerator and fly ash from the combustion air heat exchanger. Preliminary equipment design information for the ash slurry system is listed in Table 1- 13. Table 1-13. Ash Slurry System Design Criteria Equipment Units Specifications Clinker Grinder Number of Units No.4 Material Handled MHI bottom ash heat exchanger fly ash Maximum Size Passing In.1/4 Type Double-Roll Ash Slurry Tanks Number of Units No.4 Material Handled MHF bottom ash and combustion air heat exchanger fly ash Tank Dimensions Length Width Height ft 10’-0” 10’-0” 6’-0” BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 27 Table 1-13. Ash Slurry System Design Criteria Equipment Units Specifications Ash Slurry Concentration %0.5 to 1 Ash Slurry Pumps Number of Units (per incinerator)No.8(4Duty, 4Standby) Material Handled Ash Slurry Incinerator Ash Flow Rate pph 1,950 Combustion Air Heat Exchanger Flow Rate pph 150 Maximum Flow Rate at Maximum Speed gpm 850 Minimum Flow Rate at Reduced Speed gpm 425 Discharge Point Ash Lagoons Discharge Head at Maximum Flow ft 100 Motor hp 35 1 Ash flow rate based on low volatile (58% VS) condition and incinerator capacity. (5)Alternative B-2 -Fluidized Bed Incinerator System For Alternative B-2, fluidized bed incinerator (FBI) trains will be installed in a new solids processing building. Each incinerator vessel will consist of three zones: hot windbox, sand bed, and freeboard. Preheated fluidizing air will be directed into the windbox and distributed to the bed through tuyeres in a refractory arch. The air will fluidize the sand bed above the refractory arch and will provide combustion air for the process. Dewatered cake will be pumped into the incinerator through multiple injection nozzles and into the sand bed. Auxiliary fuel injection lances (fuel oil or natural gas) will provide supplemental fuel, if needed. All exhaust gases. Including combustion products and ash, will exit the fluidized bed incinerator through the freeboard and exhaust gas duct. Figure 1-7 illustrates the proposed Alternative B-2. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 28 Figure 1-7: Alternative B-2 – New FBIs Each incinerator is designed to process the total projected feed solids at annual average conditions. For maximum month conditions, both incinerators will be required to operate. Preliminary equipment design information for the FBIs is listed in Table 1-14. Table 1-14. Fluidized Bed Incinerator Design Criteria Equipment Units Specifications Fluid Bed Incinerators Number of Units No.2 Operation Schedule h/d/wk 24/7/52 Required Capacity (each)dtpd 120 Incinerator Vessel Type Refractory lined w/ refractory arch BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 29 Table 1-14. Fluidized Bed Incinerator Design Criteria Equipment Units Specifications Windbox Hot Air Size Freeboard Diameter Height ft 34 45 Wall Construction Inner layer of walls and dome Outer layer of walls and dome Refractory Brick Insulated Fire Brick Number of Solids Feed Nozzles No.Multiple around periphery, 4 minimum Auxiliary Fuel Source Natural Gas and Fuel Oil Minimum Natural Gas Pressure psig 10 Discharge Temperature oF 1,500 -1,650 max Preheat Provisions Preheat supplied by natural gas fired burner (6)Alternative B-2 -Primary and Secondary Heat Exchangers Primary and secondary heat exchangers will recover waste heat from the exhaust gases. The primary heat exchanger will transfer heat from the incinerator exhaust gases to the fluidizing air. A primary heat exchanger bypass (with damper) will control the temperature of the fluidizing air and heat recovery. This “hot windbox” design is expected to reduce the amount of auxiliary fuel required for combustion and, in some cases, may allow autogenous (without additional fuel) combustion. Following the primary heat exchanger, a secondary heat exchanger will transfer heat from the exhaust gases to the scrubber outlet gas. Heating the scrubber outlet gas prior to discharge to the atmosphere will help suppress visible plumes. The secondary heat exchanger may also be used to pre-heat exhaust to future emission control equipment. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 30 Preliminary equipment design information for the primary and secondary heat exchangers is listed in Table 1-15. Table 1-15. Primary and Secondary Heat Exchangers Design Criteria Equipment Units Specifications Primary Heat Exchanger Number of Units No.2 Type Shell and Tube Configuration Vertical, Counterflow Design Temperatures Exhaust gas in Exhaust gas out Fluidizing air in Fluidizing air out oF 1,650 1,200 60 1,030 Size Vessel Diameter Height ft 12 30 Design Pressure psig 10 Secondary Heat Exchanger Number of Units No.2 Type Shell and Tube Configuration Vertical, Counterflow Design Temperatures Exhaust gas in Exhaust gas out Scrubber outlet gas in Scrubber outlet gas out oF 1,200 1,050 100 300 Design Pressure psig 10 (7)Alternative B-2 – Air Pollution Control Equipment Exhaust gases leaving the secondary heat exchangers will be directed to the air pollution control equipment. Initial air pollution control equipment will include quench sprays and BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 31 wet scrubbers. The quench spray section will consist of multiple water sprays that cool the exhaust gases prior to entering the wet scrubber. The new scrubber will be a vertical upflow unit with impingement trays used for cooling and saturating the gas, followed by a multiple fixed venturi section with water injection and mist eliminators with sprays. Plant effluent water will be used for the impingement trays. Strained plant effluent water will be used for the venturi injection and high pressure spray lances. Service water (potable water downstream of a backflow preventer) will be used for the mist eliminator sprays. Booster pumps will be supplied with the scrubbers for venturi and high pressure spray lance water injection. Strained plant effluent water is required for the venturi injection and high pressure spray lances to prevent nozzle clogging while potable water is required for the mist eliminator to prevent fouling. Preliminary equipment information for the wet scrubber is listed in Table 1-16. Table 1-16. Wet Scrubber Design Criteria Equipment Units Specifications Wet Scrubbers Number of Units No.2 Type Combined Impingement Tray, and Multiple Fixed Venturis Configuration Vertical, Upflow Dimensions, ft Diameter Height ft 14 30 Water Requirements (per scrubber) Quench Sprays Under Tray Sprays Impingement Trays Venturi Section Mist Eliminator gpm 150 60 1,650 200 15 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 32 (8)Alternative B-2 – Ash Handling System For FBIs, a small fraction of the ash is collected at the waste heat boilers (for power generation option only) while the majority of the ash is removed by the wet scrubber. A new ash slurry system including ash slurry pumps and slurry tanks is recommended to handle the ash slurry from the bottom of the scrubber. The new ash slurry system will collect the scrubber drain water including the ash and transfer it to the existing ash lagoons. Preliminary equipment design information for the ash slurry system is listed in Table 1-17. Table 1-17. Ash Slurry System Design Criteria Equipment Units Specifications Ash Slurry Tanks Number of Units No.2 Material Handled FBI and WHB fly ash Tank Dimensions Length Width Height ft 15’-0” 10’-0” 8’-0” Ash Slurry Concentration %0.5 to 1 Ash Slurry Pumps Number of Units (per incinerator)No.4(2Duty, 2Standby) Material Handled Ash Slurry Incinerator Ash Flow Rate pph 4,200 Maximum Flow Rate at Maximum Speed gpm 1,700 Minimum Flow Rate at Reduced Speed gpm 850 Discharge Point Ash Lagoons Discharge Head at Maximum Flow ft 100 Motor hp 70 1 Ash flow rate based on low volatile (58% VS) condition and incinerator capacity. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 33 (9)Alternative B-2 -Fluidizing Air Blower Each incinerator will have a dedicated blower to supply fluidizing air. The fluidizing air will be drawn from outside the solids processing building, and will be preheated in the primary heat exchanger before entering the FBI windbox. Fluidizing air serves two purposes: to suspend the solids in the incinerator bed and to provide combustion air. Preliminary equipment design information for the fluidizing air blowers is listed in Table 1-18. Table 1-18. Fluidizing Air Blower Design Criteria Equipment Units Specifications Fluidizing Air Blowers Number of Units No.2 Type Multiple-Stage Centrifugal Drive Direct Required Flow scfm 13,000 Flow Adjustment Inlet Damper Pressure Rise psig 8 Motor hp 700 (10) Alternative B-2 -Fuel Storage Tank and Pumps Fuel oil will be delivered to the site by tankers and stored in an above ground storage tank located next to the new solids processing building. Fuel oil transfer pumps will be installed in the fuel oil storage area to transfer fuel oil from the storage tank to a day tank. A second set of pumps, fuel oil feed pumps, will be used to transfer fuel oil from the day tank to each incinerator. The fuel oil, which will be used for supplemental fuel during incinerator warm up, will be injected into the incineration process through fuel injection lances. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 34 Preliminary equipment design information for the fuel storage tank and pumps is listed in Table 1-19. Table 1-19. Fuel Oil Storage Tank and Pumps Design Criteria Equipment Units Specifications Fuel Oil Tank Type Double wall, above ground Number of Units No.1 Tank Size Diameter Length ft 12 30 Volume gal 20,000 Fuel Oil Transfer Pumps Number of Units No.2 (1 Duty, 1 Standby) Type Gear Required Flow gpm 60 Minimum Discharge Pressure psi 5 Motor hp 1 Fuel Oil Day Tank Number of Units No.1 Tank Size Diameter Total Height ft 6 9 Volume gal 1,600 Fuel Oil Injection Pumps Number of Units No.3 (2 Duty, 1 Standby) Type AFD, Gear Type Required Flow gpm 4 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 35 Table 1-19. Fuel Oil Storage Tank and Pumps Design Criteria Equipment Units Specifications Minimum Discharge Pressure psi 50 Motor hp 0.5 (11) Alternative B-2 -Sand System Sand will be delivered to the site by truck and stored in an indoor sand storage tank. Pneumatic transporters will convey sand from the sand storage tank to each of the FBIs to replenish sand entrained in the exhaust gas stream. Preliminary equipment design information for the sand storage system is listed in Table 1-20. Table 1-20. Sand System Design Criteria Equipment Units Specifications Storage Tanks Number of Units No.1 Type Vertical with dual conical base Volume1 cf 360 Storage months 1 to 9 Size Diameter Total Height2 ft 9 40 Transporters Number of Units No.2 Compressed Air Requirements Flow, scfm Pressure range, psig scfm psig 150 100-120 1 Silo capacity based on sand demand of 50 lbs/hr for one incinerator. Feed rate for BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 36 make up sand range from 5 to 50 lbs/hr.2 Silo height includes clearances for transport and dust collection equipment. (12) Alternative B-2 -Energy Recovery Options Waste heat from the exhaust gases will be used to generate steam in the waste heat boilers. Two end use options for the steam have been evaluated: a) Medium pressure saturated steam for sale to Trigen; b) High pressure superheated steam for power generation. Energy recovery options will only be considered for Alternative B-2 due to limited space available at the Bissell Point WWTP site. (13) Steam Generation – Steam Sale to Trigen Option B-2-A For this option, waste heat will be used to generate medium pressure steam that will be sold to Trigen. The waste heat remaining in the flue gas downstream of the primary heat exchangers will be used in waste heat boilers to generate steam. Exhaust gas from the waste heat boiler will be treated through the secondary heat exchanger. Heat removed from the exhaust gas will be transferred to the scrubber outlet gas for plume suppression. Figure 8 below illustrates the proposed steam generation option for Option B-2-A. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 37 Figure 8: Option B-2-A – New FBIs with Optional Steam Generation (14) Waste Heat Boilers – B-2-A Flue gases from the each FBI will be ducted to waste heat boilers. The waste heat boilers will recover heat from the incinerator exhaust gases to produce medium pressure saturated steam. A bypass will be provided around the waste heat boilers to allow the steam production equipment to be taken out of service without affecting incinerator operation. Preliminary equipment design criteria for the waste heat boilers are listed in Table 1-21. Table 1-21. Waste Heat Boiler Design Criteria Equipment Units Specifications Waste Heat Boilers Number of Units No.2 Type Water Tube Flue Gas Conditions BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 38 Table 1-21. Waste Heat Boiler Design Criteria Equipment Units Specifications Flue Gas Pressure psia 14.7 Flue Gas Inlet Temperature oF 1,200 Flue Gas Outlet Temperature oF 500 Design Flue Gas Flow1 pph 111,550 Flue Gas Flow at AA Conditions (70% VS and 28% TS) pph 68,250 Flue Gas Flow at AA Conditions (58% VS and 35% TS) pph 66,500 Steam Conditions Steam Pressure psia 180 Steam Temperature oF 373 (saturated) Steam Flow at AA Conditions (70% VS and 28% TS)pph 15,100 (each boiler) Steam Flow at AA Conditions (58% VS and 35% TS) pph 14,400 (each boiler) Waste Heat Fly Ash Transport System (From waste heat boiler to ash storage silo)2 Number of surge hoppers No.2 Type Dry ash surge hopper capacity cf Vertical with Conical Base 1 Number of pneumatic transporters No.2 Type Air flow Operating pressure scfm psig Dense Phase 15 100 Number of compressors No.2 (one duty, one standby) Type Compressor capacity Compressor motor scfm hp Scroll or Screw Type 50 5 1 Design exhaust flow rate for waste heat boiler based on incinerator capacity at 70% VS BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 39 and 28% TS.2 Required for options with dry ash handling. For options where dry ash handling is not required, the ash transport system will transfer the waste heat boiler fly ash to the wet slurry tanks. (15) Water Treatment System – B-2-A A package type water treatment system will be provided to treat potable water for boiler water make up. The water treatment equipment will depend on the potable water quality and make up water quality requirements. The water treatment system will consist of cartridge filters, carbon filters, water softeners, reverse osmosis (RO), demineralizers, demineralized water storage tank, and make up water pumps. The water treatment systems will include standby components to support 7 day, 24 hour incinerator operation during water system equipment cleaning and regeneration. The water softening and the demineralizer systems will require periodic regeneration; the RO system will require a periodic clean-in-place (CIP). All regeneration and CIP is expected to be performed off- site through a service contract. The calculated capacities for the packaged water treatment system were based on a “once through system” with no condensate return. Preliminary equipment design information for the packaged water system is listed in Table 1-22. Table 1-22. Packaged Water Treatment Design Criteria Equipment Units Specifications Water Treatment System Number of Units No.2 (1 Duty, 1 Standby) Water source Potable Water Required treated water flow rate gpm 40 to 50 Design Pressure Loss As required by vendor Make Up Water Tank Capacity gal 3,000 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 40 Table 1-22. Packaged Water Treatment Design Criteria Equipment Units Specifications Packaged Water Treatment System Pumps (Booster pumps to waste heat boiler) Number of Units No.4 (2 Duty, 2 Standby) Water source Treated Water Flow Rate gpm 50 Discharge Pressure ft 600 Motor hp 20 (16) Power Generation Option – B-2-B In this option, waste heat remaining in the exhaust gases after the primary heat exchanger will be used in waste heat boilers to generate high pressure superheated steam. The superheated steam will be used in steam turbines to generate electricity, which will be used on-site to reduce electricity purchases. The generated electricity will be used onsite. Following the waste heat boiler, a secondary heat exchanger will transfer heat from the exhaust gases to the scrubber outlet gas for plume suppression. Figure 1-9 illustrates the proposed Option B-2-B power generation option. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 41 Figure 1-9: Alternative B-2-B – FBIs with Power Generation (17) Waste Heat Boilers – B-2-B Flue gases from the FBI will be ducted to a new waste heat boiler. The waste heat boiler will recover heat from the incinerator exhaust gases to produce high pressure superheated steam for power generation. A bypass will be provided around the waste heat boilers to allow the steam production equipment to be taken out of service without affecting incinerator operation. Preliminary equipment design information for the waste heat boilers is listed in Table 1- 23. Table 1-23. Waste Heat Boiler Design Criteria (for Power Generation) Equipment Units Specifications Waste Heat Boilers Number of Units No.2 Type Water Tube BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 42 Table 1-23. Waste Heat Boiler Design Criteria (for Power Generation) Equipment Units Specifications Flue Gas Conditions Flue Gas Pressure psia 14.7 Flue Gas Inlet Temperature oF 1,150 Flue Gas Outlet Temperature oF 500 Design Flue Gas Flow1 pph 111,550 Design Flue Gas Flow at AA Conditions (70% VS and 28% TS) pph 68,250 Design Flue Gas Flow at AA Conditions (58% VS and 35% TS) pph 66,500 Steam Conditions Steam Pressure psia 400 Steam Temperature oF 600 (superheated) Steam Flow at AA Conditions (70% VS and 28% TS) pph 11,800 (each boiler) Steam Flow at AA Conditions (58% VS and 35% TS) pph 11,300 (each boiler) Waste Heat Fly Ash Transport System (From waste heat boiler to ash storage silo)3 Number of surge hoppers No.2 Type Dry ash surge hopper capacity cf Vertical with Conical Base 1 Number of pneumatic transporters No.2 Type Air flow Operating pressure scfm psig Dense Phase, Conical Base 15 100 Number of compressors No.2 (one duty, one standby) Type Compressor capacity Compressor motor scfm hp Scroll or Screw Type 50 5 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 43 1 Design flow rate for waste heat boiler based on incinerator capacity at 70% VS and 28% TS). 2 Steam flow rates shown include deduction for parasitic loads (i.e., de-aerator, etc.).3 Required for options with dry ash handling. For options where dry ash handling is not required, the ash transport system will transfer the waste heat boiler fly ash to the wet slurry tanks. (18) Steam Turbine Generator – B-2-B One steam turbine generator will convert steam to electrical power. The skid-mounted steam turbine will be installed in the new sludge processing building and will include an oil lubrication system, mounted on a separate skid. Preliminary equipment design information for the steam turbine generator is listed in Table 1-24. Table 1-24. Steam Turbine Generator Design Criteria Equipment Units Specifications Steam Turbine Number of Units No.1 Type Full condensing to 4 in. Hg absolute Steam conditions Steam Pressure psia 400 Steam Temperature oF 600 (superheated) Design Steam Flow1 pph 16,400 Generator speed rpm 4,750 Alternator Speed rpm 1,800 Power output – AA (70% VS and 28% TS)MW 1.0 Power output – AA (58% VS and 35% TS)MW 0.8 Output Voltage V 4,160 Type Synchronous BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 44 1 Steam turbine sized for steam rate prior to parasitic load deduction. Power output based on net steam rate after parasitic load deduction. (19) Steam Condenser – B-2-B One steam condenser will be provided to condense steam from the turbine. The condensate will be returned to the waste heat boiler steam drum. Preliminary equipment design information for the steam condenser and condensate pumps is listed in Table 1-25. Table 1-25. Steam Condenser and Condensate Pumps Design Criteria Equipment Units Specifications Steam Surface Condenser Number of Units No.1 Type Water Cooled Temperature of Condensate oF 125 Operating Pressure in Hga 4 Cooling Water Recirculated Potable Water Cooling Water Supply Temperature oF 85 Cooling Water Return Temperature oF 105 Condensate Pumps Number of Units No.2(1Duty,1Standby) Type Vertical Multistage Centrifugal Design Flow Rate gpm 30 Approximate Head ft 60 Approximate Motor size hp 1.5 Drive Constant Speed BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 45 (20) Cooling Water Heat Exchangers – B-2-B A once-through cooling system, consisting of heat exchangers and pumps, will provide cooling water to the steam condensers. Plant effluent water (PEW) will be used as the coolant. A portion of the heated PEW exiting the cooling water heat exchangers will be used in the incinerator wet scrubber system impingement trays. Preliminary equipment design information for the cooling heat exchanger is listed in Table 1-26. Table 1-26. Cooling Water Heat Exchanger Design Criteria Equipment Units Specifications Cooling Water Heat Exchangers Number of Units No.2 (1 Duty + 1 Standby) Type Plate and frame Cooling Fluid Type PEW Approximate Flow gpm 1,500 Design Pressure Drop psi 10 Design Inlet Temperature oF 80 Design Outlet Temperature oF 100 Cooled Fluid Type Recirculated potable water Approximate Flow gpm 1,400 Design Pressure Drop psi 10 Design Inlet Temperature oF 105 Outlet Temperature oF 85 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 46 (21) Condensate Handling System – B-2-B A condensate handling system consisting of deaerators, condensate storage tank, and waste heat boiler feed water pumps will be provided to condition, store and pump condensate in the closed-loop waste heat boiler steam system. Preliminary equipment design information for the condensate handling system is listed in Table 1-27. Table 1-27. Condensate Handling System Design Criteria Equipment Units Specifications Condensate Storage Tank Number of Units No.1 Type Vertical, Carbon Steel. Capacity min 30 Capacity gal 900 Deaerator Number of Units 1 Type Tray Type Condensate flow rate pph 16,400 Steam Flow pph 1,000 to 2,000 Sump Storage 10 minutes Waste Heat Boiler Feed Pumps Number of Units 2 (1 Duty, 1 Standby) Type Centrifugal Design flow rate gpm 30 Approximate head ft 1,200 Approximate motor size hp 30 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 47 (22) Water Treatment System – B-2-B A package type water treatment system will be provided to treat potable water for boiler water make up. The water treatment equipment will depend on the potable water quality and make up water quality requirements. The water treatment system will consist of cartridge filters, carbon filters, water softeners, reverse osmosis (RO), demineralizers, demineralized water storage tank, and make up water pumps. The water treatment systems will include standby components to support 7 day, 24 hour incinerator operation during water system equipment cleaning and regeneration. The water softening and the demineralizer systems will require periodic regeneration; the RO system will require a periodic clean-in-place (CIP). All regeneration and CIP is expected to be performed off- site through a service contract. Preliminary equipment design information for the packaged water system is listed in Table 1-28. Table 1-28. Packaged Water Treatment Design Criteria Equipment Units Specifications Packaged Water Treatment Number of Units No. 2 (1 Duty, 1 Standby) Required Treated Water Flow Rate gpm 15 Design Pressure Loss As Required by Vendor Make Up Water Tank Capacity gal 1,800 (23) Future Advanced Air Pollution Control – B-2-C Regulations associated with mercury discharge from sludge incinerators are anticipated to change in the next five to ten years. Regulatory restrictions are currently being imposed on plants in the Northeast United States and may be adopted throughout the country. The regulation modifications are expected to require the addition of an advanced air pollution control system for mercury removal from incinerator exhaust gases. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 48 Mercury differs from other metals in the incineration process. Metals in the incinerator feed solids typically are removed from the process entrained in the ash or through the wet scrubber. While some mercury becomes entrained in the ash or is collected in the wet scrubber, the remainder is volatilized as elemental mercury (Hg0) in the incinerator. As the gaseous elemental mercury is cooled through the remaining processes, it can react with other components of the flue gas to form oxidized gaseous mercury (Hg2+). The components can be halogens (chlorine, fluorine, and bromine) or oxides of sulfur, such as sulfur dioxide (SO2) and sulfur trioxide (SO3) or nitrogen, such as nitrogen dioxide (NO2). Little mercury is typically retained in the ash. A fraction of the oxidized mercury (Hg2+) is soluble in water and is captured in the wet scrubbing process. The elemental species, which has low solubility in water and is emitted from the stack, must be oxidized and removed through scrubbing. The exhaust gases from the secondary heat exchanger will be directed to the advanced air pollution control system. Air pollution control equipment for mercury removal includes an exhaust gas conditioning tower, carbon injection tower, carbon storage, fabric filter (followed by previously described wet scrubber), dry ash system, and ID fan. Figure 10 shows the main mercury scrubbing process using carbon injection and a fabric filter. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 49 Figure 10: Advanced Air Pollution Control System w/ Mercury Scrubbing Mercury removal may also be accomplished by fixed bed carbon scrubbers. Comparison of the different mercury scrubbing options was not included for this evaluation, but it is recommended prior to final system selection. Descriptions of the various advanced air pollution control equipment required for a carbon injection system are included below. (24) Conditioning Tower – B-2-C The exhaust gases leaving the secondary heat exchanger will be directed to the gas conditioning tower, where it will be cooled adiabatically using a small amount of BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 50 atomized PEW. The conditioning tower system includes the gas conditioning vessel, atomized water-air spray lances, water booster pumps and air compressors. Preliminary equipment design information for the conditioning tower system is listed in Table 1-29. Table 1-29. Gas Conditioning Equipment Design Criteria Equipment Units Specifications Gas Conditioning Equipment Number of Conditioning Towers No.2 Vessel Dimensions Diameter ft 12 Height ft 45 Design temperatures Exhaust gas in (normal operation) 1 oF 1,050 Exhaust gas in (bypass operation) oF 1,200 Exhaust gas in (from SHE with heat recovery option)oF 400 Exhaust gas out oF 300 Quench water flow – (high temperature inlet condition) gpm 40 to 50 Quench water flow – (low temperature inlet condition) gpm 10 to 20 Water design pressure psig 60 Number of Air Compressors (per tower)No.2 (1 duty, 1 standby) Compressor Dimensions Length ft 10 Width ft 6.5 Compressor Motor hp 150 1Normal operation defined as no power generation. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 51 (25) Carbon Injection and Storage – B-2-C Carbon will be injected upstream from the fabric filter for mercury removal. The mercury will adsorb onto the carbon and more than 90 percent of the mercury will be removed by the fabric filters. The removed mercury/carbon solids will be handled through the ash handling process. The carbon system will include a powdered activated carbon silo, volumetric feeder, carbon conveyance blower and carbon injection assembly. Powdered activated carbon will be delivered to the site by truck and stored in a carbon storage silo. Conveyance blowers will deliver the carbon from the carbon storage silo to the exhaust gas stream feed point ahead of the fabric filter. Preliminary equipment design information for the carbon system is listed in Table 1-30. Table 1-30. Carbon System Design Criteria Equipment Units Specifications Carbon System Number of carbon storage silos No.1 Type Vertical with conical base Volume1 Storage cf days 860 30 Size Diameter ft 12 Total Height2 ft 45 Number of carbon volumetric feeders 2 Feed rate (each)pph 30 Number of carbon conveyance blowers 2 Flow (each)scfm 100 1Carbon storage based on incinerator capacity for one unit in operation. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 52 2 Silo height includes clearances for transport and dust collection equipment. (26) Fabric Filters – B-2-C The carbon solids will form a layer on the surface of the fabric filter bags, which will act as a mercury adsorption layer. Periodic, automatic filter cleaning will be performed using compressed air. The mercury-laden carbon and other particulate matter will be collected at the bottom of each fabric filter as dry ash. The dry ash will be collected by a screw conveyor at the base of the fabric filter and pneumatically conveyed to ash storage silos. Preliminary equipment design information for the fabric filters is listed in Table 1-31. Table 1-31. Fabric Filter Design Criteria Equipment Units Specifications Fabric Filter System Number of fabric filters No.2 Type Multi-Chamber Dimensions Length Width Height ft 42 14 55 Exhaust Flow Temperature Volume1 oF acfm 350 max 45,000 No. of ash collection screw conveyors No.2 Capacity2 lb/min 70 Motor hp 25 1 Fabric filter exhaust flow rate capacity based on incinerator capacity at high volatile (70% VS) conditions. 2Ash conveyor capacity rate based on incinerator capacity and low volatile (58% VS) condition. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 53 (27) Dry Ash System – B-2-C The dry ash collected at the fabric filters will be transported to a dry ash storage silo by dense phase pneumatic conveyance systems consisting of an ash surge hopper, a pneumatic transporter, compressors and conveyance piping. The dry ash will be stored in a dry ash storage silo to be hauled off site for disposal. Preliminary equipment design information for the dry ash system is listed in Table 1-32. Table 1-32. Dry Ash System Design Criteria Equipment Units Specifications Dry Ash System Number of surge hoppers1 No.2 Type Dry ash surge hopper capacity cf Vertical with Conical Base 10 Number of pneumatic transporters1 No.2 Type Air flow Operating pressure scfm psig Dense Phase, Conical Base 100 100 Number of compressors No.2 (one duty, one standby) Type Compressor capacity Compressor motor scfm hp Scroll or Screw Type 100 25 Number of storage silos No.2 Type Vertical with Conical Base Volume (each silo) 2 Storage (AA conditions) cy days 390 7 Dimensions Diameter Total Height3 ft 24 60 1 Ash surge hopper and transporter vessel located under each fabric filter ash BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 54 conveyor. Transport system based on incinerator capacity and low volatile (58% VS) condition. 2 Ash storage based on low volatile (58% VS) and AA solids feed rate conditions. 3 Silo height includes clearances for nozzle, ash unloading equipment and truck. (28) Induced Draft Fans – B-2-C ID fans will provide additional energy to convey exhaust gases from the wet scrubber through the advanced emission control and discharge to the stack. Preliminary equipment design information for the ID Fan is listed in Table 1-33. Table 1-33. Induced Draft Fan Design Criteria Equipment Units Specifications ID Fan Number of Units 2 Type Single-Stage Centrifugal, Direct Drive Inlet Gas Temperature oF 90-130 Air Flow1 acfm 34,000 Flow Adjustment Variable Frequency Drive Pressure Rise in w.c.40 Motor hp 350 Special Construction/Materials ---316 wheels and shafts 1 Fan capacity based on incinerator capacity and high volatile (70% VS) condition. 5. Alternative B-1 – Layout Plans Refer to Figures C-1 through C-3 in Appendix C for preliminary layouts of the new wet scrubber and ash slurry systems. 6. Alternative B-2 – Layout Plans Refer to Figures C-4 through C-7 in Appendix D for preliminary layouts for the new FBIs, wet scrubbers and auxiliary systems. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 55 7. Site Plan Refer to Figure A-1 in Appendix A for a preliminary site plan showing the proposed location of the new Solids Processing Building. 8. Staffing Requirements Table 1-33 lists the anticipated staffing requirements for each of the alternatives and options. These staffing requirements are for the biosolids processing beginning with dewatering. For the options, the staffing requirements are in addition to the staffing for the alternative to which the option is added. Table 1-33. Staffing Requirements Type Value Number Hr/Shift Shift/day Day/Wk Wk/Yr Total hrs Alternative B-1 – Re-use of MHI and BFPs Supervisor 3 8 1 7 52 8,736 Operator 4.5 8 3 7 52 39,312 Maintenance 3.5 8 3 5 52 21,840 Alternative B-2 – New FBIs and Centrifuges Supervisor 3 8 1 7 52 8,736 Operator 4 8 3 7 52 39,944 Maintenance 3 8 3 5 52 18,720 Option B-2-A – Steam Generation Operator --- --- --- --- --- --- Maintenance 0.5 8 1 5 52 1,040 Stationary1 Engineer 0.5 8 3 7 52 4,368 Option B-2-B– Power Generation Operator --- --- --- --- --- --- Maintenance 1 8 1 5 52 2,080 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 56 Table 1-33. Staffing Requirements Type Value Number Hr/Shift Shift/day Day/Wk Wk/Yr Total hrs Stationary1 Engineer 1 8 3 7 52 8,736 Option B-2-C – Future Air Pollution Control Operator 0.5 8 3 7 52 4,368 Maintenance 1 8 1 5 52 2,080 1 Licensed steam boiler engineer/operator. 9. Cost Summary Table 1-34 presents the Engineer’s Opinions of Costs for construction costs, annual operation and maintenance costs, annual savings with biosolids use, and life cycle costs. These costs were determined based on the descriptions of alternatives and options presented here. These costs and benefits were developed and presented in Technical Memorandum No.9 Opinions of Costs for Alternatives. All costs and savings are in 2010 dollars. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 57 Table 1-34. Opinions of Costs, Savings and Life Cycle Costs Alternative B-1 MHI+BFP B-2 FBI +CFG B-2-A FBI + Steam B-2-B FBI + Power B-2-C FBI + AEC Capital Costs Salvage Value $56,655 ($518) $150,089 ($3,400) $13,392 ($1,106) $29,003 ($494) $25,843 ($1,156) Annual O&M Costs $7,855 $7,731 $357 $653 $246 Annual Revenue ($0)($0) ($588) ($349) ($0) Present Worth Costs Capital Salvage $56,655 ($195) $150,089 ($1,281) $13,392 ($417) $29,003 ($186) $25,843 ($436) O&M $97,896 $96,358 $4,449 $8,138 $3,068 Revenue ($0) ($0) ($7,328) ($4,355) ($0) Total Present Worth Costs $154,356 $245,166 $10,096 $32,600 $28,475 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 58 Appendix A Site Plan BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 59 Appendix B Detailed Process Flow Schematics Figure B-1 Figure B-2 Figure B-3 Figure B-4 Figure B-5 Figure B-6 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Bissell Point WWTP Alternative Evaluation Re-Issued: September 10, 2010MSD Contract No. 2009145 Reviewed by: B. Green 60 Appendix C Layout Plans: Existing MHI and New Solids Processing Building Appendix E – B&V Solids Handling MP TM-2 (Sub-Regional Lemay) BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 1 TECHNICAL MEMORANDUM NO. 2 – LEMAY WWTP SOLIDS PROCESSING ALTERNATIVES EVALUATION To: Metropolitan St. Louis Sewer District From: Jim Rowan, Gustavo Queiroz, Patricia Scanlan, Hari Santha This Technical Memorandum presents information on the solids processing and management alternatives evaluated for the Lemay Wastewater Treatment Plant (WWTP) as part of developing a strategic plan for long-term management of biosolids. Information on the existing facilities for the planning effort was obtained from existing plant records, interviews with MSD staff, and plant permits. The following sections describe the existing biosolids management system, the solids quantities used as the basis of the evaluation, and the treatment options evaluated for Lemay. Table of Contents 1. Existing Plant Information ......................................................................................................... 3 2. Solids Quantities ........................................................................................................................ 7 3. Solids Processing Alternatives ................................................................................................... 8 a. Alternative L-1 .....................................................................................................................8 b. Alternative L-2 .....................................................................................................................9 c. Alternative L-3 ...................................................................................................................10 4. Technologies for Solids Processing Alternatives ..................................................................... 12 a. Solids Thickening ..............................................................................................................13 b. Thickened Sludge Well ......................................................................................................13 c. Dewatering .........................................................................................................................14 (1) Alternatives L-1, L-2 and L-3 – Existing Belt Filter Press Dewatering ................. 14 (2) Alternative L-3 – New Centrifuge Dewatering ...................................................... 16 d. Cake Conveyance and Storage...........................................................................................17 (1) Alternative L-1 - Existing Cake Conveyance and Storage System ........................ 17 (2) Alternative L-2 - Existing Cake Storage System and New Cake Pumps ............... 17 (3) Alternative L-3 - New Cake Conveyance and Storage System .............................. 18 (4) Cake Storage and Load Out to Regional Facility Option ....................................... 20 e. Incinerator Systems ............................................................................................................21 (1) Alternative L-1 - Existing Multiple Hearth Incinerator Systems ............................ 23 f. Alternative L-1 - Air Pollution Control .............................................................................25 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 2 g. Alternative L-1 – Induced Draft (ID) Fans ........................................................................27 h. Alternatives L-2 and L-3 - Fluidized Bed Incinerator System ..........................................27 (1) Alternatives L-2 and L-3 – Primary and Secondary Heat Exchangers ................... 29 (2) Alternatives L-2 and L-3 – Air Pollution Control Equipment ................................ 31 (3) Alternatives L-2 and L-3 – Ash Handling System.................................................. 32 (4) Alternatives L-2 and L-3 - Fluidizing Air Blower .................................................. 33 (5) Alternatives L-2 and L-3 - Fuel Storage Tank and Pumps ..................................... 33 (6) Alternatives L-2 and L-3 - Sand System................................................................. 35 (7) Energy Recovery Option - Power Generation – L-1-A, L-2&3-A ......................... 36 i. Waste Heat Boiler – L-1-A and L-2&3-A .........................................................................38 j. Steam Turbine Generator – L-1-A and L-2&3-A ..............................................................40 k. Steam Condenser – L-1-A and L-2&3-A ...........................................................................41 l. Cooling Water Heat Exchangers – L-1-A and L-2&3-A ...................................................42 m. Condensate Handling System – L-1-A and L-2&3-A .......................................................43 n. Water Treatment System – L-1-A and L-2&3-A ...............................................................45 (1) Future Air Pollution Control – L-1-B and L-2&3-B .............................................. 45 o. Conditioning Tower – L-1-B and L-2&3-B.......................................................................48 p. Carbon Injection and Storage – L-1-B and L-2&3-B ........................................................49 q. Fabric Filters – L-1-B and L-2&3-B ..................................................................................50 r. Dry Ash System – L-1-B and L-2&3-B .............................................................................51 s. Induced Draft Fans – L-1-B and L-2&3-B ........................................................................53 (1) Alternative L-1 – Layout Plans ............................................................................... 54 (2) Alternatives L-2 and L-3 Layout Plans ................................................................... 54 5. Site Plan ................................................................................................................................... 54 6. Staffing Requirements ............................................................................................................. 54 7. Cost Summary .......................................................................................................................... 55 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 3 1. Existing Plant Information The Lemay WWTP was commissioned in 1968. The WWTP has an average design capacity of 167 mgd and peak hydraulic design capacity of 233 mgd. The plant has both primary and secondary treatment. A site plan of the Lemay WWTP is shown in Figure 2-1. Figure 2-1: Lemay WWTP Site Plan The WWTP generates primary solids (PS) and waste activated solids (WAS), which are co- thickened in primary clarifiers to approximately 3 percent total solids (TS). Scum is collected from the primary and secondary clarifiers, pumped to scum thickeners and then pumped to three sludge wells where they are combined with the co-thickened sludge pumped from the primary clarifiers. The combined solids are dewatered by belt filter presses (BFP) to approximately 28 percent TS. There are six belt filter presses, but not all are continually used. Polymer is added to the sludge at a rate of approximately 10 lb of active polymer per dry ton of solids (lb/dt). Bottom BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 4 sludge from the scum thickeners are returned to the aeration tanks and filtrate from the BFPs are combined in drainage wells and returned to the primary clarifiers. The dewatered cake from the BFPs is discharged to belt conveyors and screw conveyors, which convey it to two equalization bins. Belt conveyors are used to feed the dewatered cake from the equalization bins to four multiple hearth incinerators (MHIs). The MHIs thermally oxidize the dewatered cake to produce ash and exhaust gases. The exhaust gases from the incinerators are treated using wet scrubbers and the ash is pumped in slurry form to three ash lagoons located off site. Waste heat from the exhaust gases is recovered downstream from each incinerator exhaust for use in a waste heat boiler to generate medium pressure steam for building heat. A schematic of the existing solids treatment processes is presented in Figure 2-2. Figure 2-2: Existing Solids Processes at Lemay WWTP BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 5 The specifications of the existing solids processing facilities at the WWTP are summarized in Table 2-1. Table 2-1. Rated Capacities of Existing Solids Processing Equipment Equipment Units Value SOLIDS DEWATERING Belt Filter Presses (BFP) Number of BFPs No. 6 Belt Width m 2 Hydraulic Capacity gpm/m 125 INCINERATOR EQUALIZATION BINS Live Bottom Bins (Screw Type) Number of Equalization Bins No. 2 Capacity2 cy 10 INCINERATION Multiple Hearth Incinerators (MHI) Number of MHIs No. 4 Capacity (per incinerator)1 Incinerator No.1 Incinerator No.2 Incinerator No.3 Incinerator No.4 dtpd 59 66 52 77 1 Incinerator capacity information provided by MSD. 2 Equalization bin capacity information provided by MSD. Pictures of the existing solids processing facilities are shown in Figure 2-3. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 6 Belt Conveyors Cake Equalization Bins Wet Scrubber Venturi Section Multiple Hearth Incinerators Figure 2-3. Existing Solids Processing Facilities at the Lemay WWTP BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 7 2. Solids Quantities The solids quantities for this evaluation were carried forward from Phase I – TM 2: Facility Summaries and Solids Projections and are summarized in Table 2-2. Table 2-2. Projected Solids Quantities Parameter Units Max. Month Ann. Avg. Primary Sludge Total Solids dtpd 30.0 21.0 Volatile Solids Fraction % of TS 45.5 50.5 Volatile solids dtpd 13.7 10.6 Waste Activated Sludge Total Solids dtpd 64.0 30.1 Volatile Solids Fraction % of TS 45.5 50.5 Volatile solids dtpd 29.1 15.2 Total Solids Total Solids dtpd 94.0 51.1 Volatile Solids Fraction % of TS 45.5 50.5 Volatile solids dtpd 42.8 25.8 Solids Concentration % 1.5 1.5 Flow gpd 1,502,800 816,900 The primary solids quantities listed in Table 2-2 reflect the primary treatment facilities wet weather expansion. Since the Lemay watershed is mature, no dry weather growth is expected. Therefore, the future WAS solids quantities for process evaluations were assumed to be the same as current conditions. The projected solids quantities presented lower than typical volatile solids (VS) concentrations in PS and WAS. The lower volatile solids (VS) concentration may be attributed to the higher fraction of inorganics in the plant influent during high flows. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 8 The maximum month (MM) quantities were used as the basis for equipment sizing at Lemay, except for the fluidized bed incinerator alternative, the size for which is described in more detail in the following section. The annual average quantities were used as the basis for determining the operations and maintenance (O&M) costs for the evaluation. The other assumptions used for the process evaluations are as follows:  Co-thickened solids (PS + WAS) concentration of 1.5 percent from primary clarifiers.  Solids capture efficiency of 98 percent in BFP dewatering units.  Solids capture efficiency of 98 percent in centrifuge dewatering units.  Dewatered cake solids concentration of 30 percent from belt filter presses and 35 percent from centrifuges.  Two days of storage at maximum month conditions for cake storage silos (load out to regional facility).  Volume calculations for cake storage and conveyance equipment based on 30 percent TS. 3. Solids Processing Alternatives Based on discussions with the District staff and site visits to the Lemay WWTP, three alternatives were developed for processing and management of biosolids generated at the Lemay WWTP. Descriptions of the alternatives are presented in the following sections. Refer to Appendix B of this report for detailed process flow schematics for all alternatives. a. Alternative L-1 This alternative is the base-case scenario and will include re-use of the existing cake handling equipment, belt filter presses, multiple hearth incinerators, ash handling, air pollution control systems, and heat recovery. Modifications and upgrades to the existing systems will be required and are discussed later in this report. This alternative will also include options for additional air pollution control systems and heat recovery. The heat recovery evaluation includes power generation to reduce plant electricity purchased from the electrical utility serving the plant. Figure 2-4 illustrates the overall process flow diagram for Alternative 1. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 9 Figure 2-4: Solids Flow Diagram - Alternative L-1 b. Alternative L-2 This alternative consists of re-use of the existing belt filter presses and cake equalization bins, new incinerator feed pumps (located in the existing dewatering room of the Incinerator and Filter Building), new solids processing facilities including fluidized bed incinerators (FBIs), air pollution control systems and heat recovery. The air pollution control system evaluation includes options for mercury removal and dry ash handling. The heat recovery evaluation includes power generation to reduce plant electricity purchased from the electrical utility serving the plant. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 10 Based on the larger size for the new fluidized bed incinerator and preliminary assessment of the existing Incinerator and Filter Building, it was determined that the current available space is not sufficient to house the new larger fluidized bed incinerator and associated equipment. In addition, the construction of a new solids processing facility will provide additional flexibility allowing the existing solids processing system to remain in operation during construction phase of the new facility. Figure 2-5 illustrates the overall process flow diagram for Alternative 2. Figure 2-5: Solids Flow Diagram - Alternative L-2 – New FBI and Existing BFPs c. Alternative L-3 This alternative consists of new solids processing facilities including dewatering centrifuges, re- use of existing belt filter presses (during low volatile conditions), equalization bins, incinerator BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 11 feed pumps, fluidized bed incinerators, air pollution control systems and heat recovery. The air pollution control system evaluation includes options for mercury removal and dry ash handling. The heat recovery evaluation includes power generation to reduce plant electricity purchased from the electrical utility serving the plant. Based on the larger size for the new fluidized bed incinerator and preliminary assessment of the existing Incinerator and Filter Building, it was determined that the current available space is not sufficient to house the new larger fluidized bed incinerator and associated equipment. In addition, the construction of a new solids processing facility will provide additional flexibility allowing the existing solids processing system to remain in operation during construction phase of the new facility. Figure 2-6 illustrates the overall process flow diagram for Alternative 3. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 12 Figure 2-6: Solids Flow Diagram - Alternative L-3 – New FBI and New Centrifuges A summary of the new and existing equipment being evaluated for each alternative is presented in Table 2-3. Table 2-3. Solids Processing Alternatives Equipment Alternative L-1 Alternative L-2 Alternative L-3 Re-Use BFPs and MHIs Re-Use BFPs and New FBIs New CFs and FBIs Dewatering Belt Filter Presses E E E Dewatering Centrifuges --- --- N Dewatered Cake Equalization Bins E E N Sludge Cake Storage/Loadout1 --- --- --- Incinerator Cake Feed Pumps --- N N Multiple Hearth Incinerators E --- --- Fluidized Bed Incinerators --- N N Air Pollution Control (Wet Scrubber) E N N Advanced Air Pollution Control (Fine Particulate and Mercury Removal with Dry Ash Handling) N N N Legend: E = Existing system will be evaluated and modifications/upgrades recommended. N = The implementation of a new system will be evaluated. Notes: 1 Sludge cake storage/load out will be considered for regional facility option only. 4. Technologies for Solids Processing Alternatives The solids processing technologies considered to support the three alternatives are discussed in the following sections. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 13 a. Solids Thickening The existing primary clarifiers will continue to be used to co-thicken PS and WAS to approximately 1.5 percent TS. Since solids production is not expected to increase during the planning period, no additional thickening capacity will be required. It is important to note that if MSD implements biological phosphorus removal in the future, co- thickening is not recommended. Co-thickening PS and WAS can create anaerobic conditions and re-release phosphorous in the primary clarifiers, reducing the overall phosphorous removal efficiency. MSD is considering the addition of Biological Nutrient Removal (BNR) with phosphorous removal at the Bissell Point WWTP. If biological phosphorous removal is added at Lemay in the future, WAS should be thickened in a separate process. WAS thickening technologies are not evaluated as part of this report. b. Thickened Sludge Well The existing thickened sludge well is expected to have sufficient capacity to process future solids and will not be evaluated for this report. The existing thickened sludge well mixing system has experienced clogging problems due to rags and other non-biodegradable materials present in the thickened sludge stream. To improve this issue, an in-line grinder system is recommended to be installed upstream of the thickened sludge well. Preliminary equipment design information for the thickened sludge grinders is listed in Table 2- 4. Table 2-4. Thickened Sludge Grinders Design Criteria Equipment Units Specifications Thickened Sludge Grinder Number of Units No. 2 (1 Duty, 1 Standby) BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 14 Table 2-4. Thickened Sludge Grinders Design Criteria Equipment Units Specifications Type In-line Operation Schedule Alternative 1 Alternative 2 h/d/wk 24/7/52 24/5/52 Inlet Cake Solids % 1.5 Rated Flow (each) gpm 1,100 Expected Pressure Drop psig 1.60 Motor hp 5 1 Existing CTPWS pump capacities will need to be further investigated during detailed design to verify that existing pumps are of sufficient capacity to overcome the additional head imposed by the new thickened sludge grinders. c. Dewatering (1) Alternatives L-1, L-2 and L-3 – Existing Belt Filter Press Dewatering Alternatives L-1 and L-2 include BFP dewatering. Based on the projected solids quantities listed in Table 2-2, the six existing dewatering BFPs and the BFP feed pumps are expected to have adequate capacity. However, based on age and expected life of the existing equipment, the dewatering equipment will need to be replaced or significantly overhauled during the evaluation period. For Alternative L-3, the existing BFP units will be retained (without overhaul) and used during low volatile solids conditions. Preliminary equipment design information for dewatering BFPs and BFP feed pumps are listed in Table 2-5. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 15 Table 2-5. BFPs and Feed Pumps Design Criteria Equipment Units Specifications Belt Filter Presses Number of Units1,2 No. 6 Operation Schedule h/d/wk 24/7/52 Belt width m 2 Hydraulic Loading Rate3 gpm/m 125 Solids Loading Rate3 pph/m 940 Solids capture rate % 98 Feed Solids % 1.5 Cake Solids % 30 Polymer use (active) lb/dt solids 10-15 BFP Feed Pumps Number of units No. 6 Pump type4 Centrifugal (Wemco vortex type) Flow (each) gpm 250 1 For Alternative L-1 (BFP with MHI), three (3) BFP units will be required to process solids at AA conditions and seven day operation schedule. A total of five (5) BFP units will be required to process solids at MM conditions and seven day operation schedule. Refer to Table 2-11 for proposed MHI operation. 2 For Alternatives L-2 and L-3 (BFP with FBI), four (4) BFP units will be required to process solids at AA conditions and five day operation schedule. A total of six (6) BFP units will be required to process solids at MM conditions and five day operation schedule. Refer to Table 2-14 for proposed FBI operation. 3 Loading rates listed are based on feedback from MSD for current operation. 4 Pump type selected to match existing BFP feed pumps. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 16 (2) Alternative L-3 – New Centrifuge Dewatering Alternative L-3 includes new centrifuge dewatering. For this alternative, the co-thickened sludge will be pumped from the existing sludge wells to new centrifuges located in a new Solids Processing Building. Preliminary equipment information for the centrifuges and centrifuge feed pumps is listed in Table 2-6 below. Table 2-6. Centrifuge and Centrifuge Feed Pump Design Criteria Equipment Units Specifications Centrifuges Number of Units1 No. 6 (5 Duty, 1 Standby) Operation Schedule h/d/wk 24/5/52 Rated Capacity gpm/machine 292 Required Hydraulic Loading Rate2 gpm/machine 292 Required Solids Loading Rate2 pph/machine 2,193 Approximate Diameter in. 23 Solids Capture Rate % 98 Feed Solids % 1.5 Cake Solids % 35 Polymer Use (active) lb/dt solids 15-20 Centrifuge Feed Pumps Number of units No. 6 (5 Duty, 1 Standby Pump type3 --- Centrifugal with AFD (Wemco vortex type) Flow (each) gpm 292 1 Three (3) centrifuges are required to process solids feeding one FBI at AA conditions, and five (5) centrifuges are required to process solids feeding one FBI at MM conditions. 2 Required centrifuge loading rates based on AA conditions for 5-day operation. 3 Pump type selected to match existing BFP feed pumps. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 17 d. Cake Conveyance and Storage (1) Alte rnative L-1 - Existing Cake Conveyance and Storage System Belt and screw conveyors are used to transfer dewatered cake from the existing BFPs to live- bottom (screw type) equalization bins (see Figure 2-2). The equalization bins discharge solids to belt conveyors that feed the incinerators. The capacity of the existing belt conveyors, screw conveyors, live-bottom and equalization bins will be sufficient for the future solids production; however, replacement of some existing equipment may be required during this project due to equipment age. Preliminary cake conveyance and storage equipment requirements are presented in Table 2-7. Table 2-7. Existing Cake Conveyance and Storage Equipment Design Criteria Equipment Units Specifications Dewatered Cake Conveyor System Conveyor type Belt Required capacity1 cf/h 440 Equalization Bins Number of units No. 2 Type Live bottom (screw) Required volume (each)2 cy 10 1 Required capacity based on MM solids conditions and seven day operation. 2 Equalization bin sizing based on existing equipment. (2) Alternative L-2 - Existing Cake Storage System and New Cake Pumps Existing screw and belt conveyors will be used to transfer dewatered cake from the existing BFPs to live-bottom (screw type) equalization bins (see Figure 2-5). New piston-type cake pumps will feed cake from the equalization basins to the new FBI incinerator. The capacity of BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 18 the existing belt conveyors, screw conveyors and live-bottom equalization bins will be sufficient for the future solids production; replacement of some existing equipment may be required during this project due to equipment age. The new cake pumps will be equipped with additional piping for cake load out to be used during times when the incinerator systems are not operating. Preliminary cake conveyance and storage equipment specifications are presented in Table 2-8 below. Table 2-8. Existing Cake Conveyance and Storage Equipment Design Criteria Equipment Units Specifications Dewatered Cake Conveyor System Conveyor type Belts/Screws Required capacity1 cf/h 620 Equalization Bins Number of units No. 2 Type Live bottom (screw) Required volume (each)2 cy 10 Dewatered Cake Pumps Number of units No. 4 (2 Duty, 2 Standby) Pump type Hydraulic piston (Dual Discharge) Flow Measurement Type Magnetic Flow Meter Required flow (each)3 gpm 50 1 Required capacity based on MM solids conditions and five day operation. 2 Equalization bin sizing based on existing equipment. 3 Cake pumps sized to transfer dewatered cake at incinerator capacity. (3) Alternative L-3 - New Cake Conveyance and Storage System A new cake conveyance and storage system will be required for Alternative L-3. The system will be located in the new Solids Processing Building with new FBI. Shafted screw conveyors BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 19 will be used to transfer dewatered cake from the centrifuges to cake transfer pumps that will feed the equalization bins, as shown on Figure 2-6. The hopper will be equipped with a sliding frame-type live bottom, which will discharge solids to piston-type cake pumps feeding the incinerator. The new cake pumps will be equipped with additional piping for cake load out to be used during times when the incinerator systems are not operating. Preliminary equipment design information for the sludge conveying and storage facilities is listed in Table 2-9. Table 2-9. New Cake Conveying and Storage Equipment Design Criteria Equipment Units Specifications Dewatered Cake Conveyor System Number of units No. 2 Conveyor type1 Shafted Screw Required capacity (each)2 cf/h 330 Cake Transfer Pumps (from dewatered cake conveyors to equalization bins) Number of units No. 2 (1 Duty, 1 Standby) Conveyor type Hydraulic piston (Dual Discharge) Required flow (each) gpm 50 Equalization Bins Number of units No. 2 Type Live bottom (Sliding Frame) Required volume (each)3 cy 35 Dewatered Cake Pumps (from equalization bin to incinerator) Number of units No. 4 (2 Duty, 2 Standby) Pump type Hydraulic piston (Dual Discharge) Flow Measurement Type Magnetic Flow Meter Required flow (each)4 gpm 50 1 Shafted screw conveyors used for this evaluation. Shaft-less screw type conveyors may be evaluated during detailed design. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 20 2 Required capacity based on FBI incinerator capacity. 3 Equalization bins sized for approximately 3 hours of storage capacity for each incinerator at 70 dtpd. 4 Cake pumps sized to transfer dewatered cake at incinerator capacity. (4) Cake Storage and Load Out to Regional Facility Option A new cake storage and load out system will be required for the option of hauling dewatered solids to a Regional Facility for incineration. The new cake storage and load out system will be located in a new building, east of the existing Incinerator and Filter Building. Cake transfer pumps will be required to transfer dewatered cake from the cake equalization bins to cake storage silos, as shown on Figure 2-4. The silo will be equipped with a sliding frame type live bottom, which will discharge solids to trucks that will transfer dewatered cake to the Regional Facility. Cake recirculation pumps will be provided as part of the cake storage system to help reduce the amount of odorous gases released from the stored cake. Cake load out is only considered for the Regional Facility option (refer to the Regional Facility chapter of this report). Incinerator upgrades at Lemay would not be required for a Regional Facility option. Preliminary equipment design information for the cake storage and load out facility is listed in Table 2-10. Table 2-10. New Cake Storage and Load Out Equipment Design Criteria Equipment Units Specifications Cake Transfer Pumps (feeding storage silos from existing equalization bins) Number of units No. 2 (one per equalization bin) Pump type Hydraulic piston (Dual Discharge) Required flow (each)1 gpm 55 Dewatered Cake Storage Silo (Truck Loading) Number of units No. 2 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 21 Table 2-10. New Cake Storage and Load Out Equipment Design Criteria Equipment Units Specifications Type Live bottom (Sliding Frame) Storage capacity2 days 2 Required volume (each) cy 390 Dewatered Cake Storage Silo Recirculation Pumps3 Number of units No. 4 (2 Duty, 2 Standby) Pump type Hydraulic piston Volume turnover hr 6 Turnover capacity cy/hr 65 Required flow (each) gpm 220 1 Cake transfer pump capacity based on MM conditions. 2 Cake storage based on MM conditions. 3 The use of the cake recirculation pump concept for odor reduction will be verified during detailed design. e. Incinerator Systems Incinerator systems process dewatered sludge by means of high temperature thermal oxidation (combustion). The dewatered cake is conveyed (for Alternative L-1) or pumped (for Alternatives L-2 and L-3) to the incinerators that oxidize the organic fraction in the solids, generating exhaust gases and ash. Many plants currently use multiple hearth incinerators (MHI) to burn dewatered cake generated at their facility. Most of the MHIs were built in the 1970s and 1980s. With over 20 years or more of service they are requiring repairs and upgrades to continue operation. Owners are asking if it is worthwhile to spend the resources to upgrade or replace the units with fluidized bed incinerators (FBI). Table 2-11 presents a discussion of the merits and concerns with upgrading MHIs or replacing them with new FBIs. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 22 Table 2-11. Incinerator Technologies Comparison Item MHI FBI Comment Unit capacity and Sizing 23 ft. diameter MHI will burn 25 to 50 dry tons per day of dewatered sewage solids. The typical FBI will burn 50 to 120 dtpd of solids with most units sized for about 100 dtpd. For every two MHIs, one FBI can match or exceed their capacity, reducing the number of units and space needed. Operation skill and complexity Generally requires one operator per 1 or 2 units to adjust and monitor Typically requires less time with one operator assigned to dewatering and incineration operation. Plant operators, who have experience with both, report that operation of a FBI is less demanding than for a MHI. Cost No new MHIs are being built. Many are undergoing repairs, rebuilding and emissions control upgrades with equipment and installation costs of $2M to $6M per unit. FBIs have equipment and installation costs of $15M to $20M per unit. New FBIs typically require a new building and support facilities, resulting in costs of $30M to $40M for a single unit. For comparison, costs for upgrading MHIs (2 units) would range from $4M to $12M and would provide same or less capacity than one FBI. Emission Controls The MHIs currently use wet scrubbers consisting of a variation of venturis, impingement scrubbers, and wet electrostatic precipitators for particulate and acid gas removal from exhaust gases. CO, THC, and NOx are controlled by operational parameters including temperature and oxygen content. There is no mercury control. FBIs use similar wet scrubbers as MHIs but are inherently better combustion devices with lower emissions of CO, THC, and NOx. Mercury removal has been used for FBIs. New regulations will lower emission limit requirements for both types with the MHIs being impacted the most for CO, NOx and Hg emissions. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 23 Table 2-11. Incinerator Technologies Comparison Item MHI FBI Comment Turndown MHIs will burn under turn down conditions but with some additional fuel usage. FBIs can also be turned down but with much less efficient operation. To accommodate lower feed rates, FBIs are operated in a weekly batch mode where they burn the solids at design rates until the weekly quantity is depleted. Then they are “bottled up” until the cycle repeats. Some auxiliary fuel will be used for warming prior to introducing solids again. Both type incinerators operate more efficiently at design loading. MHIs are more appropriate for small facilities with FBIs used for large facilities. Power generation from incineration Can be implemented to produce electricity with steam/steam turbine. Steam at 400 psia. Can be implemented to produce electricity with steam/steam turbine. Steam at 400 psia. Power produced is proportional to the volatile solids burned. For 100 dtpd feed rate, 1 to 1.5 MW produced. Descriptions for each incinerator system alternative are provided in the following sections. (1) Alternative L-1 - Existing Multiple Hearth Incinerator Systems Alternative L-1 retains the existing MHIs. Three of the existing four MHIs are expected to provide sufficient capacity for the projected solids quantities in Table 2-2. However, based on age and life of the MHI equipment, the MHIs are expected to need significant rehabilitation during the evaluation period. Three of the four existing MHIs will be rehabilitated to support the projected solids loading conditions. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 24 The incinerators are sized such that one of the three incinerator trains must be operated to process annual average solids quantities. Two incinerators must be operated to support maximum month solids quantities. The third incinerator will provide spare capacity at maximum month conditions. For this base alternative, the existing waste heat boilers will be rehabilitated and continue to produce steam for building heat. Figure 2-7 illustrates the proposed Alternative L-1 MHI incineration system. Figure 2-7: Alternative 1 – Reuse of MHIs Preliminary equipment design information for the MHIs is listed in Table 2-12. Table 2-12. Multiple Hearth Incinerators Design Criteria Equipment Units Specifications Multiple Hearth Incinerators Number of Units No. 3 (2 Duty, 1 Standby) BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 25 Table 2-12. Multiple Hearth Incinerators Design Criteria Equipment Units Specifications Operation Schedule h/d/wk 24/7/52 Required Capacity (each)1 dtpd 60 Incinerator Vessel Type No. of Hearths Multiple Hearth 11 Size Diameter Height ft ft 22’-3” 45 Wall Construction Inner Layer of Walls Outer Layer of Walls Outer Layer of Top Refractory brick Insulated fire brick High duty castible Auxiliary Fuel Source Natural gas Min Natural Gas Pressure psig 10 Exhaust Temperature oF 1,100-1,400 1 Average incinerator capacity used for calculation purposes. f. Alternative L-1 - Air Pollution Control The existing impingement tray scrubbers, induced draft (ID) fans, and associated exhaust ductwork will be replaced to reduce particulate emissions and provide additional operational flexibility. The new scrubbers will re-use the existing scrubber vessels, but will require new internal components. In addition, the upper section of the existing scrubber vessels will be extended to accommodate new multiple venturi sections. New exhaust gas quench sections will be added to pre-condition the exhaust gases before entering the wet scrubbers. The new scrubber will be a vertical upflow unit with impingement trays used for cooling and saturating the gas, followed by a multiple fixed venturi section with water injection and mist BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 26 eliminators with sprays. Plant effluent water will be used for the impingement trays. Strained plant effluent water will be used for the venturi injection and high pressure spray lances. Service water (potable water downstream of a backflow preventer) will be used for the mist eliminator sprays. Booster pumps will be supplied with the scrubbers for venturi and high pressure spray lance water injection. Strained plant effluent water is required for the venturi injection and high pressure spray lances to prevent nozzle clogging while potable water is required for the mist eliminator to prevent fouling. Preliminary equipment design information for the wet scrubber and quench section are listed in Table 2-13. Table 2-13. Wet Scrubber and Quench Section Design Criteria Equipment Units Specifications Wet Scrubbers and Quench Station Number of Units No. 3 (2 Duty, 1 Standby) Type Combined impingement tray, and multiple fixed venturis Configuration Vertical, up flow Pressure Drop in w.c. 30 Dimensions Diameter Height ft 12 30 Water Requirements (per scrubber) Quench Section Sprays Under Tray Sprays Impingement Trays Venturi Section Sprays Mist Eliminator gpm 100 60 1,200 150 10 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 27 g. Alternative L-1 – Induced Draft (ID) Fans New ID fans will be required to overcome the increased pressure drop associated with the new wet scrubbers. The ID fans will be located in the same area as the existing fans. The ID fans will pull the clean gas from the air pollution control equipment and discharge it to the stack. Preliminary equipment design information for the ID fans is listed in Table 2-14. Table 2-14. Induced Draft Fan Design Criteria Equipment Units Specifications Induced Draft Fans Number of Units No. 3 (2 Duty, 1 Standby) Type Single stage centrifugal, direct drive Inlet Gas Temperature oF 90-130 Required Capacity acfm 22,000 Flow Adjustment Variable Frequency Drive Pressure Rise (design) in w.c. 44 Motor hp 250 Special Construction/Materials 316 SS wheels and shafts h. Alternatives L-2 and L-3 - Fluidized Bed Incinerator System Alternatives L-2 and L-3 will include a single fluidized bed incinerator (FBI) train, installed in the new Sludge Processing Building. The incinerator vessel will consist of three zones: hot windbox, sand bed, and freeboard. Preheated fluidizing air will be directed into the windbox and distributed to the bed through tuyeres in a refractory arch. The air will fluidize the sand bed above the refractory arch and will provide combustion air for the process. Dewatered cake will be pumped into the incinerator through multiple injection nozzles and into the sand bed. Auxiliary fuel injection lances (fuel oil or natural gas) will provide supplemental fuel, if needed. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 28 All exhaust gases, including combustion products and ash, will exit the fluidized bed incinerator through the freeboard and exhaust gas duct. Alternatives 2 and 3 are shown on Figure 2-8. Figure 2-8: Alternatives L-2 and L-3 – New FBIs Preliminary equipment design information for the FBIs is listed in Table 2-15. Table 2-15. Fluidized Bed Incinerator Design Criteria Equipment Units Specifications Fluid Bed Incinerators Number of Units1 No. 2 Operation Schedule h/d/wk 24/5/52 Required Capacity (each) dtpd 70 Incinerator Vessel Type Refractory lined w/ refractory BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 29 Table 2-15. Fluidized Bed Incinerator Design Criteria Equipment Units Specifications Windbox arch Hot Air Size Freeboard Diameter Height ft 24 45 Wall Construction Inner layer of walls and dome Outer layer of walls and dome Refractory Brick Insulated Fire Brick Number of Solids Feed Nozzles Multiple around periphery, 4 minimum Auxiliary Fuel Source Natural Gas and Fuel Oil Minimum Natural Gas Pressure psig 10 Exhaust Temperature oF 1,500-1,650 max Preheat Provisions Preheat supplied by natural gas fired burner 1 One incinerator will have sufficient capacity to process total projected feed solids at annual average conditions and five day operation. Two incinerators will be required to operate during maximum month conditions and five day operation. (1) Alternatives L-2 and L-3 – Primary and Secondary Heat Exchangers Primary and secondary heat exchangers will recover waste heat from the exhaust gases. The primary heat exchanger will transfer heat from the incinerator exhaust gases to the fluidizing air. A primary heat exchanger bypass (with damper) will control the temperature of the fluidizing air and heat recovery. This “hot windbox” design is expected to reduce the amount of auxiliary fuel required for combustion and, in some cases, may allow autogenous (without additional fuel) combustion. Following the primary heat exchanger, a secondary heat exchanger will transfer heat from the exhaust gases to the scrubber outlet gas. Heating the scrubber outlet gas prior to discharge to the BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 30 atmosphere will help suppress visible plumes in the incinerator exhaust. The secondary heat exchanger may also be used to pre-heat exhaust to future emission control equipment. Primary and secondary heat exchanger information is presented in Table 2-16. Table 2-16 Primary and Secondary Heat Exchangers Design Criteria Equipment Units Specifications Primary Heat Exchanger Number of Units No. 2 Type Shell and Tube Configuration Vertical, Counterflow Design Temperatures Exhaust gas in Exhaust gas out Fluidizing air in Fluidizing air out oF 1,650 1,200 60 1,030 Size Vessel Diameter Height ft 10 30 Design Pressure psig 10 Secondary Heat Exchanger Number of Units No. 2 Type Shell and Tube Configuration Vertical, Counterflow Design Temperatures Exhaust gas in Exhaust gas out Scrubber outlet gas in Scrubber outlet gas out oF 1,200 1,050 100 300 Design Pressure psig 10 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 31 (2) Alternatives L-2 and L-3 – Air Pollution Control Equipment Exhaust gases leaving the secondary heat exchangers will be directed to the air pollution control equipment. Air pollution control equipment will include quench sprays and wet scrubbers. The quench spray section will consist of multiple water sprays used to cool the exhaust gases prior to entering the wet scrubber. The new scrubber will be a vertical upflow unit with impingement trays used for cooling and saturating the gas, followed by a multiple fixed venturi section with water injection and mist eliminators with sprays. Plant effluent water will be used for the impingement trays. Strained plant effluent water will be used for the venturi injection and high pressure spray lances. Service water (potable water downstream of a backflow preventer) will be used for the mist eliminator sprays. Booster pumps will be supplied with the scrubbers for venturi and high pressure spray lance water injection. Strained plant effluent water is required for the venturi injection and high pressure spray lances to prevent nozzle clogging while potable water is required for the mist eliminator to prevent fouling. Wet scrubber equipment information is presented in Table 2-17. Table 2-17. Wet Scrubber Design Criteria Equipment Units Specifications Wet Scrubbers Number of Units No. 2 Type Combined Impingement Tray, and Multiple Fixed Venturis Configuration Vertical, Upflow Dimensions, ft Diameter Height ft 14 30 Water Requirements (per scrubber) Quench Sprays Under Tray Sprays Impingement Trays Venturi Section Mist Eliminator gpm 100 50 1,400 150 15 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 32 (3) Alternatives L-2 and L-3 – Ash Handling System For FBIs, a small fraction of the ash is collected at the waste heat boilers (for power generation option only) while the majority of the ash is removed by the wet scrubber. A new ash slurry system including ash slurry pumps and slurry tanks is recommended to handle the ash slurry from the bottom of the scrubber. The new ash slurry system will collect the scrubber drain water including the ash and transfer it to the existing ash lagoons. Preliminary equipment design information for the ash slurry system is listed in Table 2-18. Table 2-18. Ash Slurry System Design Criteria Equipment Units Specifications Ash Slurry Tanks Number of Units No. 2 Material Handled Fly ash from FBIs Tank Dimensions Length Width Height ft 10’-0” 10’-0” 8’-0” Ash Slurry Concentration % 0.5 to 1 Ash Slurry Pumps Number of Units (per incinerator) No. 4 (2 Duty, 2 Standby) Material Handled Ash Slurry Incinerator Ash Flow Rate pph 2,920 Maximum Flow Rate at Maximum Speed gpm 1,170 Minimum Flow Rate at Reduced Speed gpm 585 Discharge Point Ash Lagoons Discharge Head at Maximum Flow ft 100 Motor hp 50 1 Ash flow rate based on low volatile (50% VS) condition and FBI incinerator capacity. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 33 (4) Alternatives L-2 and L-3 - Fluidizing Air Blower The incinerator will have a dedicated blower to supply fluidizing air. The fluidizing air will be drawn from outside the Solids Processing Building, and will be preheated in the primary heat exchanger before entering the FBI windbox. Fluidizing air serves two purposes: to suspend the solids in the incinerator bed and to provide combustion air. Equipment information for the fluidizing air blowers is presented in Table 2-19. Table 2-19. Fluidizing Air Blower Design Criteria Equipment Units Specifications Fluidizing Air Blower Number of Units No. 2 Type Multiple-Stage Centrifugal Drive Direct Required Flow scfm 10,500 Flow Adjustment Inlet Damper Pressure Rise psig 8 Motor hp 600 (5) Alternatives L-2 and L-3 - Fuel Storage Tank and Pumps Fuel oil will be delivered to the site by truck and stored in an above ground storage tank located next to the new Solids Processing Building. Fuel oil transfer pumps will be installed in the fuel oil storage area to transfer fuel oil from the storage tank to a day tank. A second set of pumps, fuel oil feed pumps, will be used to transfer fuel oil from the day tank to each incinerator. The fuel oil, which will be used for supplemental fuel during incinerator warm up, will be injected into the incineration process through fuel injection lances. Equipment requirements for the fuel storage tank and pumps are listed in Table 2-20. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 34 Table 2-20. Fuel Oil Storage Tank and Pumps Design Criteria Equipment Units Specifications BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 35 Fuel Oil Tank Number of Units 1 Type Double wall, above ground Tank Size Diameter Length ft 10 20 Volume gal 10,000 Fuel Oil Transfer Pumps Number of Units No. 2 (1 Duty, 1 Standby) Type Gear Required Flow gpm 20 Minimum Discharge Pressure psi 5 Motor hp 0.5 Fuel Oil Day Tank Number of Units No. 1 Tank Size Diameter Height ft 3 10 Volume gal 500 Fuel Oil Injection Pumps Number of Units No. 2 (1 Duty, 1 Standby) Type AFD, Gear Type Required Flow gpm 1 Minimum Discharge Pressure psi 50 Motor hp 0.25 (6) Altern atives L-2 and L-3 - Sand System BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 36 Sand will be delivered to the site by truck and stored in an indoor sand storage tank. A pneumatic transporter will convey sand from the sand storage tank to the FBI to replenish sand entrained in the exhaust gas stream. Preliminary equipment design information for the sand storage system is shown in Table 2-21. Table 2-21. Sand System Design Criteria Equipment Units Specifications Storage Tank Number of Units No. 1 Type Vertical with dual conical base Volume1 cf 360 Storage months 1 to 9 Size Diameter Total Height2 ft 9 40 Transporters Number of Units No. 2 Compressed Air Requirements Flow, scfm Pressure range, psig scfm psig 150 100-120 1 Silo capacity based on sand demand of 50 lbs/hr for one incinerator. Feed rate for make up sand range from 5 to 50 lbs/hr. 2 Silo height includes clearances for transport and dust collection equipment. (7) Energy Recovery Option - Power Generation – L-1-A, L-2&3-A Option L-1-A will include waste heat boilers and on-site power generation. Waste heat from the exhaust gases will be recovered downstream from the incinerator exhaust for use in waste heat boilers to generate high pressure superheated steam for power generation. The generated electricity will be used onsite. The waste heat boilers included in this alternative will be located BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 37 in the existing Incinerator and Filter Building while the power generation equipment will require a separate stand alone building. The option L-1-A for power generation is shown on Figure 2-9. Figure 2-9: Option L-1-A – MHIs with Power Generation For options L-2&3-A, the waste heat remaining in the exhaust gases after the primary heat exchanger will be used in waste heat boilers to generate high pressure superheated steam. The superheated steam will be used in steam turbines to generate electricity, which will be used on- site to reduce electricity purchases. Following the waste heat boiler, a secondary heat exchanger will transfer heat from the exhaust gases to the scrubber outlet gas for plume suppression. Energy recovery and power generation equipment associated with Alternatives L-2 and L-3 will be located in the new Solids Processing Building. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 38 The proposed power generation options L-2&3-A are shown on Figure 2-10. Figure 2-10: Options L-2&3-A – FBI with Power Generation i. Waste Heat Boiler – L-1-A and L-2&3-A Flue gases from the incinerator(s) will be ducted to new waste heat boilers. The waste heat boilers will recover heat from the incinerator exhaust gases to produce high pressure superheated steam for power generation. Ducting from the incinerators will be configured such that either of the incinerators can provide exhaust gas to either of the waste heat boilers. Bypasse(s) will be provided around the waste heat boiler to allow the steam production equipment to be taken out of service without affecting incinerator operation. Equipment information for the waste heat boiler is provided in Table 2-22. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 39 Table 2-22. Waste Heat Boiler Design Criteria (for Power Generation) Equipment Units Specifications Waste Heat Boilers Number of Units1 No. 2 Type Water Tube Flue Gas Conditions Flue Gas Pressure psia 14.7 Flue Gas Inlet Temperature Option L-1-A Options L-2&3-A oF 1,100 1,200 Flue Gas Outlet Temperature oF 500 Design Flue Gas Flow2 Option L-1-A Options L-2&3-A pph 66,100 65,000 Flue Gas Flow at AA Conditions (each boiler)3 Option L-1-A (70% VS and 28% TS) (50% VS and 35% TS) Options L-2&3-A (70% VS and 28% TS) (50% VS and 35% TS) pph 56,300 40,300 65,000 46,600 Steam Conditions Steam Pressure psia 400 Steam Temperature oF 600 (superheated) Steam Flow at AA Conditions4 Option L-1-A (70% VS and 28% TS) (50% VS and 35% TS) Options L-2&3-A (70% VS and 28% TS) (50% VS and 35% TS) pph 7,900 5,500 11,250 7,000 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 40 Table 2-22. Waste Heat Boiler Design Criteria (for Power Generation) Equipment Units Specifications Waste Heat Fly Ash Transport System (From waste heat boiler to ash storage silo)5 Number of surge hoppers No. 2 Type Dry ash surge hopper capacity cf Vertical with Conical Base 1 Number of pneumatic transporters No. 2 Type Air flow Operating pressure scfm psig Dense Phase, Conical Base 10 to 15 100 Number of compressors No. 2 (one duty, one standby) Type Compressor capacity Compressor motor scfm hp Scroll or Screw Type 50 5 1 Boiler capacity will only be provided for duty incinerators. 2 Design exhaust flow rate for each waste heat boiler based on incinerator capacity at 70% VS and 28% TS. 3 Operation schedule of five days per week will yield biosolids quantities of approximately 71 dtpd. Five day operation is being considered for FBI alternatives only. 4 Steam flow rates shown include deduction for parasitic loads (i.e., de-aerator, etc.). 5 Required for options with dry ash handling. For options where dry ash handling is not required, the ash transport system will transfer the waste heat boiler fly ash to wet slurry tanks. j. Steam Turbine Generator – L-1-A and L-2&3-A One steam turbine generator will be used to convert steam to electrical power. The skid-mounted steam turbine will be installed in the new Solids Processing Building and will include an oil lubrication system, mounted on a separate skid. Preliminary equipment information for the steam turbine generator is listed in Table 2-23. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 41 Table 2-23. Steam Turbine Generator Design Criteria Equipment Units Specifications Steam Turbine Number of Units No. 1 Type Full condensing to 4 in. Hg absolute Steam conditions Steam Pressure psia 400 Steam Temperature oF 600 (superheated) Design Steam Flow1 Option L-1-A Options L-2&3-A pph 9,200 12,900 Turbine speed rpm 4,750 Alternator Speed rpm 1,800 Power output at AA Conditions Option L-1-A (70% VS and 28% TS) (50% VS and 35% TS) Options L-2&3-A (70% VS and 28% TS) (50% VS and 35% TS) MW 0.55 0.39 0.8 0.55 Output Voltage V 4,160 Type --- Synchronous 1 Steam turbine sized for steam rate prior to parasitic load deduction. Power output based on net steam rate after parasitic load deduction. k. Steam Condenser – L-1-A and L-2&3-A BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 42 One steam condenser will be provided to condense steam from the turbine. The condensate will be returned to the waste heat boiler steam drum. Preliminary equipment design information for the steam condenser and condensate pumps is shown in Table 2-24. Table 2-24. Steam Condenser and Condensate Pumps Design Criteria Equipment Units Specifications Steam Surface Condenser Number of Units No. 1 Type Water Cooled Temperature of Condensate oF 125 Operating Pressure in Hga 4 Cooling Water Recirculated Potable Water Cooling Water Supply Temperature oF 85 Cooling Water Return Temperature oF 105 Condensate Pumps Number of Units No. 2 (1 Duty, 1 Standby) Type Vertical Multistage Centrifugal Design Flow Rate Option L-1-A Options L-2&3-A gpm 20 25 Approximate Head ft 60 Approximate Motor size hp 1 Drive Constant Speed l. Cooling Water Heat Exchangers – L-1-A and L-2&3-A A once-through cooling system, consisting of heat exchangers and pumps, will provide cooling water to the steam condensers. Plant effluent water (PEW) will be used as the coolant. A BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 43 portion of the heated PEW exiting the cooling water heat exchangers will be used in the incinerator wet scrubber system impingement trays. Equipment information for the cooling heat exchanger is provided in Table 2-25. Table 2-25. Cooling Water Heat Exchanger Design Criteria Equipment Units Specifications Cooling Water Heat Exchangers Number of Units No. 2 (1 Duty + 1 Standby) Type Plate and frame Cooling Fluid Type PEW Approximate Flow Option L-1-A Options L-2&3-A gpm 900 1,200 Design Pressure Drop psi 10 Design Inlet Temperature oF 80 Design Outlet Temperature oF 100 Cooled Fluid Type Recirculated potable water Approximate Flow Option L-1-A Options L-2&3-A gpm 800 1,100 Design Pressure Drop psi 10 Design Inlet Temperature oF 105 Outlet Temperature oF 85 m. Condensate Handling System – L-1-A and L-2&3-A A condensate handling system consisting of deaerators, condensate storage tank, and waste heat boiler feed water pumps will be provided to condition, store and pump condensate in the closed- loop waste heat boiler steam system. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 44 Preliminary equipment information for the condensate handling system is listed in Table 2-26. Table 2-26. Condensate Handling System Design Criteria Equipment Units Specifications Condensate Storage Tank Number of Units No. 1 Type Vertical, Carbon Steel. Capacity min 30 Capacity Option L-1-A Options L-2&3-A gal 600 750 Deaerator Number of Units No. 1 Type Tray Type Condensate flow rate Option L-1-A Options L-2&3-A pph 9,200 12,900 Steam Flow pph 1,000 Sump Storage 10 minutes Waste Heat Boiler Feed Pumps Number of Units No. 2 (1 Duty, 1 Standby) Type Centrifugal Design flow rate Option L-1-A Options L-2&3 gpm 20 25 Approximate head ft 1,200 Approximate motor size Options L-1-A Options L-2&3 hp 20 25 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 45 n. Water Treatment System – L-1-A and L-2&3-A A package type water treatment system will be provided to treat potable water for boiler water make up. The water treatment equipment will depend on the potable water quality and make up water quality requirements. The water treatment system will consist of cartridge filters, carbon filters, water softeners, reverse osmosis (RO), demineralizers, demineralized water storage tank, and make up water pumps. The water treatment systems will include standby components to support 7 day, 24 hour incinerator operation during water system equipment cleaning and regeneration. The water softening and the demineralizer systems will require periodic regeneration; the RO system will require a periodic clean-in-place (CIP). All regeneration and CIP is expected to be performed off-site through a service contract. Preliminary information for the packaged water system is presented in Table 2-27. Table 2-27. Packaged Water Treatment Design Criteria Equipment Units Specifications Packaged Water Treatment Number of Units No. 2 (1 Duty, 1 Standby) Required Treated Water Flow Rate gpm 10 Design Pressure Loss As Required by Vendor Make Up Water Tank Capacity gal 1,200 (1) Future Air Pollution Control – L-1-B and L-2&3 -B Regulations associated with mercury discharge from sludge incinerators are anticipated to change in the next five to ten years. Regulatory restrictions are currently being imposed on plants in the Northeast United States and may be adopted throughout the country. The regulation modifications are expected to require the addition of an advanced air pollution control system for mercury removal from incinerator exhaust gases. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 46 Mercury differs from other metals in the incineration process. Metals in the incinerator feed solids typically are removed from the process entrained in the ash or through the wet scrubber. While some mercury becomes entrained in the ash or is collected in the wet scrubber, the remainder is volatilized as elemental mercury (HgO) in the incinerator. As the gaseous elemental mercury is cooled through the remaining processes, it can react with other components of the flue gas to form oxidized gaseous mercury (Hg2+). The components can be halogens (chlorine, fluorine, and bromine) or oxides of sulfur, such as sulfur dioxide (SO2) and sulfur trioxide (SO3) or nitrogen, such as nitrogen dioxide (NO2). Little mercury is typically retained in the ash. A fraction of the oxidized mercury (Hg2+) is soluble in water and is captured in the wet scrubbing process. The elemental species, which has low solubility in water and is emitted from the stack, must be oxidized and removed through scrubbing. For Option L-1-B, the exhaust gases from the waste heat boiler will be directed to the advanced air pollution control system. For Options L-2&3-B, the exhaust gases from the secondary heat exchanger will be directed to the advanced air pollution control system. Air pollution control equipment for mercury removal includes an exhaust gas conditioning tower, carbon injection tower, carbon storage, fabric filter (followed by previously described wet scrubber), dry ash system, and ID fan. Figure 2-11 shows the main mercury scrubbing process using carbon injection and a fabric filter. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 47 Figure 2-11: Advanced Air Pollution Control System w/ Mercury Scrubbing Mercury removal may also be accomplished using fixed bed carbon scrubbers. Comparison of the different mercury scrubbing options was not included for this evaluation, but it is recommended prior to final system selection. Descriptions of the various advanced air pollution control equipment required for a carbon injection system are included below. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 48 o. Conditioning Tower – L-1-B and L-2&3-B The exhaust gases leaving the waste heat boiler (Option L-1-B) or secondary heat exchanger (Options L-2&3-B) will be directed to the gas conditioning tower, where it will be cooled adiabatically using a small amount of atomized PEW. The conditioning tower system includes the gas conditioning vessel, atomized water-air spray lances, water booster pumps and air compressors. Preliminary equipment information for the conditioning tower system is listed in Table 2-28. Table 2-28. Gas Conditioning Equipment Design Criteria Equipment Units Specifications Gas Conditioning Equipment Number of Conditioning Towers No. 2 Vessel Dimensions Diameter ft 10 Height ft 45 Design temperatures Exhaust gas in (normal operation)1 Option L-1-B Options L-2&3-B oF 500 1,050 Exhaust gas in (from bypass) Option L-1-B Options L-2&3-B oF 1,100 1,200 Exhaust gas in (from SHE) Options L-2&3-B oF 400 Exhaust gas out oF 300 Quench water flow – (high temperature inlet condition) gpm 30 to 40 Quench water flow – (low temperature inlet condition) gpm 5 to 10 Water design pressure psig 60 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 49 Table 2-28. Gas Conditioning Equipment Design Criteria Equipment Units Specifications Number of Air Compressors No. 2 (1 duty, 1 standby) Compressor Dimensions Length ft 8 Width ft 5.0 Compressor Motor hp 100 1 For Option L-1-B, normal operation includes use of existing waste heat boiler. For Options L-2&3-B, normal operation is defined as no power generation. p. Carbon Injection and Storage – L-1-B and L-2&3-B Carbon will be injected upstream from the fabric filter for mercury removal. The mercury will adsorb onto the carbon and more than 90 percent of the mercury will be removed by the fabric filters. The removed mercury/carbon solids will be handled through the ash handling process. The carbon system will include a powdered activated carbon silo, volumetric feeder, carbon conveyance blower and carbon injection assembly. Powdered activated carbon will be delivered to the site by truck and stored in a carbon storage silo. Conveyance blowers will deliver the carbon from the carbon storage silo to the exhaust gas stream feed point ahead of the fabric filter. Preliminary equipment information for the carbon system is listed in Table 2-29. Table 2-29. Carbon System Design Criteria Equipment Units Specifications Carbon System Number of carbon storage silos No. 1 Type and Size Vertical with conical base Volume1 Storage Option L-1-B2 Options L-2&3-B cf days 500 40 30 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 50 Table 2-29. Carbon System Design Criteria Equipment Units Specifications Size Diameter ft 12 Total Height3 ft 42 Number of carbon volumetric feeders No. 2 Feed rate Option L-1-B Options 2&3-B pph 13 18 Number of carbon conveyance blowers 2 Flow (each) scfm 50 1 Carbon storage based on FBI incinerator capacity (70 dtpd). 2 Storage capacity calculated based on AA conditions for Option 1 (51.1dtpd). 3 Silo height includes clearances for transport and dust collection equipment. q. Fabric Filters – L-1-B and L-2&3-B The carbon solids will form a layer on the surface of the fabric filter bags, which will act as a mercury adsorption layer. Periodic, automatic filter cleaning will be performed using compressed air. The mercury-laden carbon and other particulate matter will be collected at the bottom of each fabric filter as dry ash. The dry ash will be collected by a screw conveyor at the base of the fabric filter and pneumatically conveyed to ash storage silos. Preliminary equipment information for the fabric filters is listed in Table 2-30. Table 2-30. Fabric Filter System Design Criteria Equipment Units Specifications Carbon System Number of fabric filters No. 2 Type Multi-Chamber BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 51 Table 2-30. Fabric Filter System Design Criteria Equipment Units Specifications Dimensions Length Width Height ft 40 12 55 Exhaust Flow Temperature Volume1 Option L-1-B Options L-2&3-B oF acfm acfm 350 max 33,000 25,000 No. of ash collection screw conveyors No. 2 Length ft 30 Capacity 2 Option L-1-B Options L-2&3-B lb/min 5 50 Motor Option L-1-B Options L-2&3-B hp 5 15 1 Fabric filter exhaust flow rate capacity based on incinerator capacity at high volatile (70% VS) conditions. 2 Ash conveyor capacity rate based on incinerator capacity and low volatile (50% VS) condition. r. Dry Ash System – L-1-B and L-2&3-B For Option L-1-B, the dry ash collected at the fabric filters will be transported to the existing ash slurry system used to process the incinerator bottom ash. For Options L-2&3-B, the dry ash collected at the fabric filters will be transported to a dry ash storage silo to be hauled off site for disposal. The dry ash system will be of the dense phase pneumatic conveyance type consisting of an ash surge hopper, a pneumatic transporter, compressors and conveyance piping. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 52 Preliminary equipment information for the dry ash system is listed in Table 2-31. Table 2-31. Dry Ash System Design Criteria Equipment Units Specifications Dry Ash System Number of surge hoppers1 No. 2 Type Dry ash surge hopper capacity Option L-1-B Options L-2&3-B cf cf Vertical with Conical Base 1 5 Number of pneumatic transporters1 No. 2 Type Air flow Option L-1-B Options L-2&3-B Operating pressure scfm scfm psig Dense Phase, Conical Base 20 60 100 Number of compressors No. 2 (one duty, one standby) Type Compressor capacity Option L-1-B Options L-2&3-B Compressor motor Option L-1-B Options L-2&3-B scfm scfm hp hp Scroll or Screw Type 50 75 15 20 Number of storage silos (Options L-2&3 only)2 No. 2 Type Vertical with Conical Base Volume3 Storage (AA Conditions) cy days 260 5 Dimensions Diameter Total Height4 ft 20 60 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 53 1 Ash surge hopper and transporter vessel located under each fabric filter ash conveyor. Transport system based on incinerator capacity and low volatile (50% VS) condition. 2 For Option L-1-B, the ash collected at the fabric filters will be transported to the existing ash slurry system. 3 Ash storage based on low volatile (50% VS) and AA solids feed rate conditions and 5 day operation. 4 Silo height includes clearances for nozzle, ash unloading equipment and truck. s. Induced Draft Fans – L-1-B and L-2&3-B ID fans will provide additional energy to convey exhaust gases through the advanced emission control and wet scrubber and discharge to the stack. Preliminary equipment information for the ID Fan is listed in Table 2-32. Table 2-32. Induced Draft Fan Design Criteria Equipment Units Specifications ID Fan Number of Units Option L-1-B Options L-2&3-B No. 3 (2 Duty, 1 Standby) 2 (1 Duty, Standby) Type Single-Stage Centrifugal, Direct Drive Inlet Gas Temperature oF 90-130 Air Flow1 Option L-1-B Options L-2&3-B scfm 23,000 20,000 Flow Adjustment Variable Frequency Drive Pressure Rise Option L-1-B Options L-2&3-B in w.c. 55 40 Motor Option L-1-B Options L-2&3-B hp 350 200 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 54 Table 2-32. Induced Draft Fan Design Criteria Equipment Units Specifications Special Construction/Materials 316 SS wheels and shafts 1 Fan capacity based on incinerator capacity and high volatile (70% VS) condition. (1) Alternative L-1 – Layout Plans Refer to Figures C-1 through C-4 in Appendix C for preliminary layouts for the new WHBs and wet scrubbers systems. (2) Alternatives L-2 and L-3 Layout Plans Refer to Figures C-5 through C-8 in Appendix C for preliminary layouts for the new FBIs, wet scrubbers and auxiliary systems. 5. Site Plan Refer to Figure A-1 in Appendix A for a preliminary site plan showing the proposed location of the new Solids Processing Building. 6. Staffing Requirements Table 2-33 lists the anticipated staffing requirements for each of the proposed alternatives. Table 2-33. Staffing Requirements Type Value Number Hr/Shift Shift/day Day/Wk Wk/Yr Total hrs Alternative L-1 (Base Case) – Re-use of MHI and BFPs Supervisor 1 8 3 7 52 8,736 Operator 3 8 3 7 52 26,208 Maintenance 3 8 2 5 52 12,480 Alternative L-2 (Base Case) – New FBIs and Re-use BFPs Supervisor 1 8 3 7 52 2,912 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 55 Table 2-33. Staffing Requirements Type Value Number Hr/Shift Shift/day Day/Wk Wk/Yr Total hrs Operator 3 8 3 7 52 26,208 Maintenance 2.5 8 2 5 52 10,400 Alternative L-3 (Base Case) – New FBIs and Centrifuges Supervisor 1 8 3 7 52 8,736 Operator 3 8 3 7 52 26,208 Maintenance 2.5 8 2 5 52 10,400 Option L-1-A and L-2&3-A – Power Generation Operator --- --- --- --- --- --- Maintenance 0.5 8 1 5 52 1,040 Stationary1 Engineer 1 8 3 7 52 8,736 Option L-1-B and L-2&3-B – Future Air Pollution Control Operator 0.5 8 3 7 52 4,368 Maintenance 1 8 1 5 52 2,080 1 Licensed steam boiler engineer/operator. 7. Cost Summary Table 2-34 presents the Engineer’s Opinions of Costs for construction costs, annual operation and maintenance costs, annual savings with biosolids use, and life cycle costs. These costs were determined based on the descriptions of alternatives and options presented here. These costs and benefits were developed and presented in Technical Memorandum No.9 Opinions of Costs for Alternatives. All costs and savings are in 2010 dollars. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 56 Table 2-34. Opinions of Costs, Savings and Life Cycle Costs ($1000) Alternative L-1 MHI+BFP L-2 FBI +BFP L-3 FBI + CFG L-1-A MHI + Power L-1-B MHI + AEC L-2&3-A FBI + Power L-2&3-B FBI + AEC Capital Costs Salvage Value $22,911 ($0) $96,098 ($1,632) $121,211 ($2,622) $29,036 ($494) $30,535 ($1,237) $24,223 ($494) $23,642 ($994) Annual O&M Costs $4,176 $4,320 $4,913 $648 $339 $565 $295 Annual Revenue ($0) ($0) ($0) ($180) ($0) ($182) ($0) Present Worth Costs Capital Salvage $22,911 ($0) $96,098 ($615) $121,211 ($988) $29,036 ($186) $30,535 ($466) $24,223 ($186) $23,642 ($375) O&M $52,045 $53,833 $61,229 $8,076 $4,223 $7,041 $3,674 Revenue ($0) ($0) ($0) ($2,245) ($0) ($2,268) ($0) Total Present Worth Costs $74,956 $149,315 $181,452 $34,681 $34,292 $28,810 $26,941 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 57 Appendix A Site Plan BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 58 Appendix B Process Flow Schematics BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Lemay WWTP Alternative Evaluation Re-Issued: September 10, 2010 MSD Contract No. 2009145 Reviewed by: B. Green 59 Appendix C Layout Plans: Existing MHI and New Solids Processing Building Appendix F – Solids Handling MP TM-9 (Opinion of Costs) BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 1 TECHNICAL MEMORANDUM NO. 9 OPINIONS OF COSTS FOR ALTERNATIVES To: Metropolitan St. Louis Sewer District From: Cecil Stegman, Patricia Scanlan, Jim Rowan, Hari Santha, Gustavo Queiroz,Yinan Qi, Bently Green _____________________________________________________________________________ Update: This technical memorandum (TM) summarizes the costs for various scenarios considered for each of the District’s wastewater treatment plants. Modifications to each of the alternatives considered were developed as part of TM’s 1 through 6. A workshop was conducted on September 10, 2010 to review the costs and concepts developed. Comments and modifications resulting from this workshop were incorporated into this TM and re-issued on January 19, 2011. However, in the meantime, USEPA had published draft emission limits for Sewage Sludge Incinerators (SSIs), which were being challenged by a number of utilities and organizations (via the public hearing process as well as written comments). As a result of these on-going regulatory issues, and the level of uncertainty that prevailed in being able to properly assess the level of improvements necessary to achieve compliance, the District requested that additional cost estimates be developed that considered relaxed limits for Mercury and utilized the existing multiple hearth incinerators indefinitely. This update to Technical Memorandum No. 9 has been completed to include those costs and is hereby re-issued as final. Table of Contents Table of Contents ............................................................................................................................ 1 List of Tables .................................................................................................................................. 2 1. Introduction ............................................................................................................................. 3 2. Cost Factors ............................................................................................................................ 5 a. Construction Cost Factors ................................................................................................ 6 b. Operation and Maintenance Cost Factors ..................................................................... 7 3. Equipment and Process Considerations ................................................................................ 10 4. Project Capital Costs ............................................................................................................. 15 5. Operation / Maintenance Costs and Revenues Generated .................................................... 27 6. Overview of Alternatives Costs ............................................................................................ 36 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 2 List of Tables Table 9-1 Summary of Alternatives Considered ................................................................ 3 Table 9-2 Construction Factors Used ................................................................................. 7 Table 9-3 Unit Costs and Revenues Used ........................................................................... 9 Table 9-4 Equipment and Modifications for Bissell, Lemay and Regional Plants .......... 11 Table 9-5 Equipment and Modifications for County Plant Alternatives .......................... 12 Table 9-6 Equipment and Modifications for the Regional Systems ................................. 13 Table 9-7 Equipment and Modifications for the Regional Systems Assuming Reduced Mercury Limits ......................................................................................... 14 Table 9-8 Capital Costs for the Bissell Point WWTP ....................................................... 17 Table 9-9 Capital Costs for the Lemay WWTP ................................................................ 19 Table 9-10 Capital Costs for the Coldwater WWTP ........................................................ 20 Table 9-11 Capital Costs for the Missouri River WWTP ................................................. 22 Table 9-12 Capital Costs for the Lower Meramec WWTP .............................................. 23 Table 9-13 Capital Costs for the Regional Plant .............................................................. 24 Table 9-14 Capital Costs for the Regional Systems ......................................................... 26 Table 9-15 Annual Costs and Revenues for Bissell Point WWTP Alternatives ............. 27 Table 9-16 Annual Costs and Revenues for Lemay WWTP Alternatives ....................... 28 Table 9-17 Annual Costs and Revenues for Coldwater WWTP Alternatives .................. 30 Table 9-18 Annual Costs and Revenues for Missouri River WWTP Alternatives .......... 32 Table 9-19 Annual Costs and Revenues for Lower Meramec Plant Alternatives ............ 33 Table 9-20 Annual Costs and Revenues for the Regional Plant Alternatives ................. 34 Table 9-21 Annual Costs and Revenues for the Regional Systems .................................. 35 Table 9-22 Summary of Cost Opinions for Bissell Plant Alternatives 1 .......................... 37 Table 9-23 Summary of Cost Opinions for Lemay Plant Alternatives 1 ......................... 38 Table 9-24 Summary of Cost Opinions for Coldwater Plant Alternatives 1 ................... 39 Table 9-25 Summary of Cost Opinions for Missouri River Plant Alternatives 1 ............. 40 Table 9-26 Summary of Cost Opinions for Lower Meramec Plant Alternatives 1 ........... 41 Table 9-27 Summary of Cost Opinions for Regional Facility Alternatives 1 .................. 42 Table 9-28 Summary of Cost Opinions for the Regional Evaluation ............................... 43 Table 9-29 Summary of Cost Opinions for the Regional Evaluation Assuming Relaxed Mercury Limits and Extending MHI Usage ............................................. 44 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 3 1. Introduction This Technical Memorandum (TM) presents the Engineer’s Opinions of Costs for construction, operations and maintenance, benefits with use of biosolids, and Present Worth costs. These costs are determined for the plant alternatives as defined in Technical Memorandums No. 1 through No. 6. Those alternatives were developed as part of Phase 1 of this study and refined as part of Phase 2 workshop conducted on June 2, 2010. Additional comments and direction from the District regarding specific elements of these alternatives were reconciled in subsequent group discussions. The costs presented here are used for comparisons, evaluations and selections of alternatives as defined in Technical Memorandum No. 10 Alternatives Selection Process and Result Table 9-1 s. A summary of the alternatives considered is provided in . Abbreviations used in the table are provided at the end of the table. Table 9-1 Summary of Alternatives Considered Alternative No. Alternative Description Bissell Point B-1 MHI+BFP Multiple hearth incineration with AEC and belt filter press dewatering. B-2 FBI+CFG Fluidized bed incineration with AEC and centrifuge dewatering. B-2-A FBI + ST Fluidized bed incineration with steam recovery. B-2-B FBI + STG Fluidized bed incineration with steam turbine power generation. Lemay L-1 MHI+BFP Multiple hearth incineration with AEC and belt filter press dewatering. L-2 FBI+BFP Fluidized bed incineration with AEC and belt filter press dewatering. L-3 FBI+CFG Fluidized bed incineration with AEC and centrifuge dewatering. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 4 Table 9-1 Summary of Alternatives Considered Alternative No. Alternative Description L-1-A MHI+STG Multiple hearth incineration with steam turbine power generation. L-2&3-A FBI+STG Fluidized bed incineration with steam turbine power generation. BFP & Centrifuge dewatering. Coldwater C-1 Current Operation Discharge of solids to Bissell collection system. C-2 BFP / Landfill Belt filter press dewatering with disposal to landfill. C-2-A CFG /Landfill Centrifuge dewatering with disposal to landfill. C-2-B RP /Landfill Rotary press dewatering with disposal to landfill. C-3 MAD / BFP Mesophilic anaerobic digestion with belt filter press dewatering. C-3-A MAD / CFG Mesophilic anaerobic digestion with centrifuge dewatering. C-3-B MAD / RP Mesophilic anaerobic digestion with rotary press dewatering. Lower Meramec LM-1 Current Operation Thickening with landfill disposal. LM-2 Thickening / Digestion Thickening with digestion and landfill disposal. Missouri River M-1 Current Operation Mesophilic anaerobic digestion with landfill disposal. M-2 Co-Digestion w/ FOG Co-digestion with fats, oils, and greases with landfill disposal. Regional R-1 FBI+CFG Fluidized bed incineration with AEC and centrifuge dewatering. R-1A FBI+ST Fluidized bed incineration with steam recovery. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 5 Table 9-1 Summary of Alternatives Considered Alternative No. Alternative Description R-1B FBI+STG Fluidized bed incineration with steam turbine power generation. Notes: Abbreviations used: AEC Advanced emission controls BFP Belt filter press dewatering MAD Mesophilic Anaerobic Digestion CFG Centrifuge dewatering FBI Fluidized bed incinerator FOG Fats, oils and greases MHI Multiple hearth incinerator RP Rotary press dewatering ST Steam system heat recovery, used for the plant or transferred to steam utility STG Steam turbine generator to produce electrical power 2. Cost Factors Costs and cost factors were developed for use in assessing overall capital and operations/maintenance costs. Costs for equipment and materials used are based on the following components and assumptions:  Support equipment and utilities including water supplies, electrical, and instrumentation and controls.  Building modifications, structural changes, new grating floors and access platforms for equipment.  Demolition of replaced equipment.  Instrumentation and controls to support new or modified equipment.  Manufacturer vendor quotes for significant equipment.  Engineer’s experience with similar projects, including power generation boilers and emissions controls.  Quantity take-offs and unit costs. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 6  In cases where existing belt filter presses are being retained, costs include maintenance repairs and overhauls for the existing presses through the life of the project.  In cases where existing incinerators are being retained, costs include new wet scrubbers to replace existing scrubbers. a. Construction Cost Factors Construction and design factors are applied to capital costs to generate total expected project costs. Capital costs include equipment, buildings, sitework, electrical, instrumentation, contingency, construction management/general conditions, bonding and insurance, and engineering costs. The cost factors used are listed in Table 9-2. . • Since the recommended incineration equipment facilities at the Bissell Point WWTP and the Lemay WWTP are similar, similar construction and design factors are used for both plants. • New buildings are assumed to have a 24 percent salvage value at the end of the project life. • Existing buildings and facilities are not assigned salvage values. • Equipment is generally assumed to have no salvage value at the end of the 20 year period but may be rebuilt or otherwise renewed to provide service for the design timeframe. • For Coldwater, Missouri River and Lower Meramec alternatives where equipment costs are large in comparison to overall costs, percentages used for electrical, instrumentation, and contractor costs have been reduced. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 7 Table 9-2 Construction Factors Used Bissell Point and Regional Facility Lemay Coldwater, Missouri River Lower Meramec Electrical 10 10 7 Instrumentation Existing Plant New Plant 4 3 4 3 3 3 Contingencies 25 25 25 Contractor Mobilization/General Requirements 10 10 6 Bonds, Insurance, Fees 5 5 5 Engineering and Legal 20 20 20 b. Operation and Maintenance Cost Factors Annual operation and maintenance (O&M) costs, disposal costs, and revenues are based on processing average annual solids production at the midpoint of the 20 year life of the projects. Power, labor, natural gas, chemicals and final use hauling and tipping costs are based on cost information supplied by MSD. Hauling costs for ash or dewatered cake to a landfill are estimated based on a 50 mile round trip and tipping fees provided by MSD. Annual benefits or savings are evaluated for alternatives where electrical power or steam is produced. If the energy is used at the plant, the value of the energy is considered to be the same as purchased energy. That is, a kilowatt of power generated on-site has the same value as a kilowatt of purchased electricity. For energy that is transferred to a third party vendor, such as steam, the value of the steam is estimated to be 75 percent of the rate charged to the vendor’s customers. The operating costs include the following:  Electricity used for process equipment and controls. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 8  Natural gas and fuel oil used for the incinerators (when required).  Operations and maintenance labor as defined for each alternative in the Alternatives Evaluation TMs.  Maintenance materials allowance for equipment (2 percent of equipment costs).  Chemicals, including thickening and dewatering polymer and odor control chemicals as identified defined in the Alternatives Evaluation TMs...  Ash disposal for the incineration alternatives.  Final use for biosolids, including composting, land application, or landfill disposal, as defined in the Alternative Evaluation TMs. Equalized unit costs for utilities and labor costs, disposal costs, and revenue sources used in the development of costs, are based on a 4 percent escalation rate and 5 percent discount rate over a 20-year period, are listed in Table 9-3. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 9 Table 9-3 Unit Costs and Revenues Used Units Bissell Point and Regional Facility Lemay Coldwater, Missouri River, & Lower Meramec Unit Costs Power $/kWh 0.102 0.012 0.102 Labor (includes benefits) Supervisor $/hr 35 35 35 Operator $/hr 30 30 30 Maintenance $/hr 32 32 32 Stationary Engineer $/hr 35 35 - Fuel Natural gas $/mmBtu 14.54 14.54 - Fuel oil $/gal 2.91 2.91 - Chemicals Polymer $/active lb 0.84 0.84 0.84 Odor control $/lb Disposal Costs Hauling $/cy 14.0 14.0 6.0 (MO River) 14.0 Landfill tipping fee $/wt - - 25.6 Hauling to Regional Facility from plant $/cy - 11.0 14.0 Ash lagoon cleanout $/cy 2 2 2 Revenue Sources Steam production $/1000 lbs -7.27 -7.27 -7.27 Power production $/kWh -0.131 -0. 131 -0. 131 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 10 3. Equipment and Process Considerations Capital costs are based on equipment and facility sizing for design year maximum month conditions for each alternative, with the exception of a few instances in which sizing or quantities were adjusted due to the available equipment size or to improve turn-down requirements. Costs are based on quotations from equipment vendors and include equipment installation, required ancillary or support equipment, repairs and replacements of existing equipment where needed, and building modifications or new buildings. Capital costs were developed for specific processes at each treatment facility; with consideration given to the potential for a future regional biosolids facility that would provide stabilization and end-use systems for all of the District’s treatment plants. Equipment modifications for each alternative considered for Bissell Point, Lemay, and a Regional Facility are shown in Table 9-4. Equipment modifications for the county facilities are provided in Table 9-5. The equipment modifications required under the regional concept are summarized in Table 9-6. Update: Table 9-7 was added to consider the impacts of reduced Mercury limits and the costs for upgrading the facilities by using the existing MHI’s for as long as possible. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives May 17, 2011 MSD Contract No. 2009145 B&V File 44.000 11 Table 9-4 Equipment and Modifications for Bissell, Lemay and Regional Plants Plant Bissell Point Lemay Regional Alternative No. B-1 B-2 B-2-A B-2-B L-1 L-2 L-3 L-1-A L-2&3-A R-1 R-1-A R-1-B Fog receiving - - - - - - - - - - - Cake Receiving R N N N - - - - - N N N Thickening R R R R R R R R R R R R Pump station and force main - - - - NR NR NR NR NR - - - Anaerobic Digestion - - - - - - - - - - - - Digester gas cleaning - - - - - - - - - - - - Dewatering R N N N R R R N R N N N Cake Handling and Storage R N N N R N N N N N N N Cake Load Out - - - - - F F F F - - - Incineration E N N N E N N N N N N N Odor Control - N N N E E E N N N N Energy recovery– steam - - N N E - - N N - N - Energy recovery – power - - - N - - N N - - N Advanced emissions Controls N N N N N N N N N N N Stack for incinerators N N N N R R R N N N Abbreviation definitions are provided following Table 9-6 Equipment and Modifications for the Regional Systems BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives May 17, 2011 MSD Contract No. 2009145 B&V File 44.000 12 Table 9-5 Equipment and Modifications for County Plant Alternatives Plant Coldwater Mo. River Lower Meramec Alternative No. C-1 C-2 C-2-A C-2-B C-3 C-3-A C-3-B M-1 M-2 LM-1 LM-2 Fog receiving - - - - - - - - N - - Cake Receiving - - - - - - - - - - - Thickening R R R R N N N R R E N Pump station and force main E - - - - - - - - - - Anaerobic Digestion - - - - E E E E E N N Digester gas cleaning - - - - N N N E E N N Dewatering - N N N N N N R R E E Cake Handling and Storage - N N N N N N E E E E Cake Load Out - N N N N N N E E E E Incineration - - - - - - - - - - - Odor Control - N N N N N N E E E E Energy recovery– steam - - - - - - - - - - - Energy recovery – power - - - - N N N N N N N Advanced emissions Controls - - - - - - - - - - - Stack for incinerators - - - - - - - - - - - Abbreviation definitions are provided following Table 9-6 Equipment and Modifications for the Regional Systems BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives May 17, 2011 MSD Contract No. 2009145 B&V File 44.000 13 Reviewed by: W. Hoener Table 9-6 Equipment and Modifications for the Regional Systems Plant Decentralized (No Regional) S-1 Regional Total System S-2 (Lemay Haul) Regional Total System S-3 (Lemay Pump) Alternative No. Bissell (B-2) Lemay (1 - 3) Coldwater (C-1) MO River (M-1) Lower Meramec (LM-1) Lemay Coldwater (C-1) MO River Lower Meramec Regional (R-1) Lemay Coldwater (C-1) MO River Lower Meramec Regional Fog receiving - - - - - - - - - - - - - - - Cake Receiving N - - - - - - - - N - - - - N Thickening R R R R E R R R E R R R R E R Pump station and force main - - E - - - E - - - NR E - - - Anaerobic Digestion - - - E N - - - - - - - - - - Digester gas cleaning - - - E N - - - - - - - - - - Dewatering N R - R E R - R E N - - R E N Cake Handling and Storage N N - E E N - E E N - - E E N Cake Load Out - F - E E F - E E - - - E E - Incineration N N - - - - - - - N - - - - N Odor Control N E - E E E - E E N E - E E N Energy recovery– steam - - - - - - - - - - - - - - - Energy recovery – power - - - N N - - - - - - - - - - Advanced emissions Controls N N - - - - - - - N - - - - N Stack for incinerators N - - - - - - - - N - - - - N BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives May 17, 2011 MSD Contract No. 2009145 B&V File 44.000 14 Reviewed by: W. Hoener Table 9-7 Equipment and Modifications for the Regional Systems Assuming Reduced Mercury Limits Plant Decentralized (No Regional) S-4 Regional Total System S-5 (Lemay Haul) Regional Total System S-6 (Lemay Pump) Alternative No. Bissell (B-2) Lemay (1 - 3) Coldwater (C-1) MO River (M-1) Lower Meramec (LM-1) Lemay Coldwater (C-1) MO River Lower Meramec Regional (R-1) Lemay Coldwater (C-1) MO River Lower Meramec Regional Fog receiving - - - - - - - - - - - - - - - Cake Receiving N - - - - - - - - N - - - - N Thickening R R R R E R R R E R R R R E R Pump station and force main - - E - - - E - - - NR E - - - Anaerobic Digestion - - - E N - - - - - - - - - - Digester gas cleaning - - - E N - - - - - - - - - - Dewatering R R - R E R - R E N - - R E N Cake Handling and Storage N N - E E N - E E N - - E E N Cake Load Out - F - E E F - E E - - - E E - Incineration E - 4 units E - 3 units - - - - - - - E - 5 units - - - - E - 5 Units Odor Control N E - E E E - E E N E - E E N Energy recovery– steam - - - - - - - - - - - - - - - Energy recovery – power - - - N N - - - - - - - - - - Advanced emissions Controls N - 4 units N - 3 units - - - - - - - N - 5 units - - - - N - 5 Units Stack for incinerators - - - - - - - - - N - - - - N BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 15 Abbreviations for the equipment modifications tables are based on the following definitions and considerations: Tag Explanation Comments E Existing equipment and process. May require modifications or upgrades F Future equipment Not included in alternative but may be required in future N New equipment or process Additional or may replace existing NR New equipment or process required for Regional Facility Only applies if Regional Facility is implemented O Optional Additional equipment for selected option R Reuse existing equipment or process Considered in good operating condition - Not required Not used for alternative 4. Project Capital Costs Table 9-8 through Table 9-14 provide capital costs for each alternative developed per treatment plant. Table 9-8 provides the capital costs for the Bissell Point facility. Alternatives B-1 and B- 2 summarize the differences between upgrading the existing MHI’s compared to abandoning the MHIs altogether and replacing them with new FBIs. The total project cost for alternative B-1 includes costs associated with a major re-build for the MHI equipment at year 10 of the project. It should be noted that during the development of feasible technologies, it was decided that the FBI alternative would include new building construction in an area between the existing solids handling building and the existing ash lagoons. It was determined that constructing the FBI’s within the existing MHI building was not feasible. Advanced emission control system will be provided for both MHI and FBI alternatives. Energy recovery as steam and steam turbine generation are shown as additional options for consideration for the FBI alternative, but are not applicable to the MHI option. As shown in the table, the opinion of project costs for the FBI are considerably higher than for the MHI alternative. The MHI alternative does not include the sunk equipment and structural costs for facilities that have been in place for more than forty years. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 16 The FBI costs are comparable to new facilities being constructed elsewhere in the U.S. for similar sized facilities. Energy recovery options generate revenue, which offset some the capital costs for implementation. These revenues are summarized in the annual cost summaries included in the following section. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 17 Table 9-8 Capital Costs for the Bissell Point WWTP ($1000) Alternative B-1 MHI+BFP B-2 FBI+CFG B-2-A FBI + ST B-2-B FBI + STG Sitework $0 $200 $0 $0 Steam Pipeline $0 $0 $3,876 $0 Structures $2,385 $14,167 $0 $2,060 Equipment $24,122 $59,011 $6,318 $14,514 Subtotal $26,507 $73,378 $10,194 $16,574 General Requirements $2,716 $7,184 $0 $0 Electrical Work $2,618 $4,514 $100 $2,177 Instrumentation and Control System $1,047 $1,934 $48 $726 Contingency $8,222 $21,753 $948 $3,629 Mid-Point of Construction $4,214 $11,148 $1,157 $2,157 Subtotal $45,324 $119,911 $12,447 $23,202 AEC $19,484 $25,843 $0 $0 Total Probable Construction Cost $64,808 $145,754 $12,447 $23,202 Engineering & Construction Services $11,331 $29,978 $3,112 $5,801 MHI Re-build (year 10) $24,145 $0 $0 $0 Total Project Cost $100,284 $175,732 $15,559 $29,003 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 18 Capital costs for the Lemay treatment facility are provided in Table 9-9. There are three primary alternatives being considered. The first alternative is an upgrade to the MHI’s for continued operation. If the MHI’s were replaced, two alternatives using new FBI’s (with variations on dewatering equipment) are also included. The total project cost for alternative L-1 includes costs associated with a major re-build for the MHI equipment at year 10 of the project. For these FBI alternatives, dewatering would be accomplished with either belt filter presses (existing technology) or with centrifuges. The additional dewatering capacity and dryer cake produced with the centrifuges impacts the overall assessment for the FBI’s, hence the variations for dewatered equipment considered. Various energy recovery and advanced emission control options are also included that could be added to the FBI option now or in the future. As with the estimates for Bissell Point, the MHI option results in the lowest capital cost, followed by the FBI with belt filter press dewatering (BFP). Alternative L-3, consisting of an FBI with centrifuge dewatering, had the highest capital cost of the three primary options considered. The BFP option assumes that the existing BFP’s will be used in the future, with periodic overhauls required. For the Lemay facility, advanced emission control will be provided for both MHI and FBI alternatives. Steam generation is considered as adders for the MHIs as well as the FBIs. The costs for these options for the MHI’s is about 20 percent higher than if used for the FBIs because of the number of heat recovery units required. The FBIs use larger, but fewer units. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 19 Table 9-9 Capital Costs for the Lemay WWTP ($1000) Alternative L-1 MHI +BFP L-2 FBI +BFP L-3 FBI +CFG L-1-A MHI +STG L-2&3-FBI +STG Sitework $0 $200 $200 $0 $0 Structures $225 $6,799 $10,927 $2,060 $2,060 Equipment $10,478 $39,527 $48,101 $12,987 $10,062 Subtotal $10,703 $46,526 $59,228 $15,047 $12,122 General Requirements $1,098 $4,606 $5,212 $0 $0 Electrical Work $1,070 $3,257 $4,146 $2,257 $1,818 Instrumentation and Control System $428 $1,396 $1,777 $752 $606 Contingency $3,325 $13,946 $17,591 $3,012 $3,031 Mid-Point of Structures $1,704 $7,147 $9,015 $2,160 $1,802 Subtotal $18,328 $76,878 $96,969 $23,228 $19,379 AEC $30,535 $23,642 $23,642 $0 $0 Total Probable Construction Cost $48,863 $100,520 $120,611 $23,228 $19,379 Engineering & Construction Services $4,582 $19,220 $24,242 $5,807 $4,845 MHI Re-build (year 10) $22,690 $0 $0 $0 $0 Total Project Cost $76,135 $119,740 $144,853 $29,036 $24,223 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 20 Capital costs for the Coldwater treatment facility are shown in Table 9-10 for three primary alternatives: 1) continuing existing operations; 2) hauling dewatered cake to a landfill; and 3) providing anaerobic digestion with disposal options consisting of composting, land application, or hauling to landfill. The dewatering options for Alternatives L-2 and L-3 consist of belt filter presses (base case); centrifuge dewatering, or rotary press dewatering. Based on costs presented, centrifuge and rotary press dewatering result in lower capital costs compared to using belt filter presses; primarily because of the additional odor control equipment required for the belt filter presses. Table 9-10 Capital Costs for the Coldwater WWTP ($1000) Alternative C-1 Current Operation C-2 Raw Cake to Landfill C-2-A CFG Dewatering C-2-B RP Dewatering C-3 Anaerobic Digestion C-3-A CFG Dewatering C-3-B RP Dewatering Sitework $3,361 $483 $483 $483 $572 $572 $572 Structures 0 $1,671 $1,671 $1,671 $3,243 $3,243 $3,243 Equipment $844 $6,331 $5,818 $5,525 $11,762 $11,587 $11,438 Subtotal $4,205 $8.485 $7,971 $7,679 $15,576 $15,401 $15,252 General Requirements $386 $840 $789 $760 $1,542 $1,525 $1,510 Electrical Work $59 $594 $558 $538 $1,090 $1,078 $1,068 Instrumentation and Control System $25 $255 $239 $230 $467 $462 $458 Contingency $308 $2,331 $2,190 $2,110 $4,280 $4,232 $4,191 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 21 Table 9-10 Capital Costs for the Coldwater WWTP ($1000) Alternative C-1 Current Operation C-2 Raw Cake to Landfill C-2-A CFG Dewatering C-2-B RP Dewatering C-3 Anaerobic Digestion C-3-A CFG Dewatering C-3-B RP Dewatering Mid-Point of Construction $511 $1,282 $1,204 $1,160 $2,353 $2,327 $2,304 Total Probable Construction Cost $5,494 $13,787 $12,953 $12,477 $25,309 $25,024 $24,782 Engineering & Construction Services $1,374 $3,447 $3,238 $3,119 $6,327 $6,256 $6,196 Total Project Cost $6,868 $17,233 $16,191 $15,596 $31,636 $31,281 $30,977 Project capital costs for the Missouri River treatment facility are provided in Table 9-11. There are two primary options for the Missouri River plant: 1) continue with existing operations with the addition of gas utilization equipment; and 2) add co-digestion with fats, oils and grease (FOG) to the existing anaerobic digestion facilities. As shown, the FOG facilities add about $1million to the overall costs. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 22 Table 9-11 Capital Costs for the Missouri River WWTP ($1000) Alternative M-1 Current Operation w/ Additional CHP M-2 Co-digestion with FOG Sitework $0 $60 Structures $792 $853 Equipment $530 $885 Subtotal $1,322 $1,738 General Requirements $131 $178 Electrical Work $93 $126 Instrumentation and Control System $40 $54 Contingency $363 $494 Mid-Point of Construction $200 $272 Total Probable Construction Cost $2,148 $2,921 Engineering & Construction Services $537 $730 Total Project Cost $2,685 $3,652 Table 9-12 provides the capital costs for the Lower Meramec treatment facility. There are two primary alternatives to consider: 1) co-thickening with anaerobic digestion; and 2) separate thickening with anaerobic digestion. Currently, solids are thickened and dewatered using belt filter presses and, then are hauled to a local landfill. Adding digestion facilities to the current treatment operations results in a significant overall modification to the plant; this is reflected in the capital cost shown in the summary. Alternative LM-1 assumes that the existing gravity thickeners are used; whereas Alternative LM-2 provides for new rotary drum thickeners for the waste activated sludge. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 23 Table 9-12 Capital Costs for the Lower Meramec WWTP ($1000) Alternative LM-1 Co-thickening and Digestion LM-2 Separate Thickening and Digestion Sitework $288 $288 Structures $12,913 $13,195 Equipment $6,766 $9,405 Subtotal $19,967 $22,887 General Requirements $1,977 $1,242 Electrical Work $1,398 $1,602 Instrumentation and Control System $599 $687 Contingency $5,486 $6,032 Mid-Point of Construction $3,016 $3,326 Total Probable Construction Cost $32,442 $35,776 Engineering & Construction Services $8,111 $8,944 Total Project Cost $40,553 $44,720 Table 9-13 summarizes the capital costs for the Regional Plant alternative which provides the base option for constructing a new FBI system on the site of the Bissell Point treatment plant in the area between the existing solids processing building and the existing ash lagoon area. Additional options for energy recovery and advanced emission controls are also included in the cost estimate. The overall base case cost includes centrifuge dewatering for improved cake solids. The regional facility is sized to accommodate solids from all seven of the District’s wastewater facilities. The capital costs for the regional facility exceeds other alternatives. However, this alternative also consolidates biosolids stabilization options for the District into one BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 24 location, and allows for greater energy recovery. This alternative also eliminates significant administrative work associated with regulatory compliance, and simplifies the District’s overall operations. Costs associated with energy recovery and advanced emission controls are also provided as adders to the base case alternatives (R-1). Table 9-13 Capital Costs for the Regional Plant ($1000) Alternative R-1 FBI+CFG R-1-A FBI+ST R-1-B FBI+STG Sitework $315 $0 $0 Structures $23,177 $0 $3,296 Steam Pipeline $0 $2,304 $0 Equipment $76,514 $10,868 $17,329 Subtotal $100,006 $13,172 $20,625 General Requirements $9,901 $0 $0 Electrical Work $7,000 $100 $3,094 Instrumentation and Control System $3,000 $48 $1,031 Contingency $29,977 $1,860 $5,156 Mid-Point of Construction $15,363 $1,532 $3,065 Subtotal $165,247 $16,482 $32,972 AEC $37,873 $0 $0 Total Probable Construction Cost $203,120 $16,482 $32,972 Engineering & Construction Services $41,312 $4,121 $8,243 Total Project Cost $244,432 $20,603 $41,215 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 25 Table 9-14 summarizes the capital costs for the regional systems alternatives. The regional system alternatives are developed to better account for hybrid plans which may include some but not all the alternatives for the individual plants with a regional solids facility. For comparison the S-1 alternative considers the total capital costs for all alternatives under a de-centralized scenario in which there is no regional facility. The hybrid regional alternatives are: S-2, consisting of a regional facility in which the Lemay plant hauls solids to the Bissell Point plant; and S-3, a regional facility in which the Lemay plant pumps their solids into the collection system for dewatering and incineration at the regional facility at the Bissell Point plant. The S-3 option is based on the assumption that a pump station is constructed in the area of the Lemay treatment facility where the belt filter press feed pumps are located (connected to the existing thickened sludge well), and that a force main conveys the Lemay solids to the Barton Drop Shaft in the Bissell Point collection system. This arrangement was determined in a meeting held on August 20, 2010 with MSD staff familiar with the collection system in this area. It was noted that although discharge of solids into the Barton Drop Shaft conveys the solids to the Bissell tunnel (Reach 4), that there are still periods of time during wet weather events (approximately 50-60 times per year) in which flow into the tunnel at this point could be conveyed to the New Mill tunnel and discharged as part of a combined system overflow. Therefore, this option may need to incorporate sludge holding facilities such that solids discharge would not occur during wet weather events. Sludge holding facilities have not been included in these costs. This decision is pending a subsequent workshop with MSD to assess the need for storage, since the existing plant can operate for up to a week without processing solids, using storage in the existing primary and secondary clarifiers. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 26 Table 9-14 Capital Costs for the Regional Systems ($1000) Alternative Decentralized (No Regional) S-1 Regional Total System S-2 (Lemay Haul) Regional Total System S-3 (Lemay Pump) Sitework $4,049 $3,971 $33,728 Structures $38,799 $28,069 $26,004 Steam Pipeline $0 $0 $0 Equipment $115,253 $87,180 $84,383 Subtotal $158,101 $119,220 $140,645 General Requirements $14,890 $11,627 $13,947 Electrical Work $10,210 $8,110 $7,594 Instrumentation and Control System $4,375 $3,475 $3,254 Contingency $45,501 $34,706 $32,531 Mid-Point of Construction $23,890 $18,156 $20,648 Subtotal $256,967 $195,293 $222,089 AEC $49,485 $37,873 $37,873 Total Probable Construction Cost $306,452 $233,166 $259,962 Engineering & Construction Services $64,242 $48,825 $55,523 Total Project Cost $370,694 $281,991 $315,485 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 27 5. Operation / Maintenance Costs and Revenues Generated A summary of the annual costs, disposal costs, and revenues for the alternatives for the various plants and facilities are provided in Table 9-15 through Table 9-20. Annual costs and revenues for the Bissell Point facility are shown in Table 9-15. Annual costs were developed for new facilities and existing costs for the dewatering and incineration equipment used to develop the costs presented. Alternative B-1 summarizes the cost for the existing MHI option; while Alternative B-2 summarizes the FBI option (with centrifuge dewatering). The overall annual cost of MHI is higher than that of FBI, primarily due to the MHIs are toward the end of their useful lives thus requiring much more maintenance than the FBIs. Chemical costs are higher for the FBI option due to the use of centrifuges that require more polymer to produce the dryer cake desired. The remaining two alternatives summarize costs associated with adding steam generation and power generation. Steam and power generation are anticipated to produce revenues that offset overall operational costs. Table 9-15 Annual Costs and Revenues for Bissell Point WWTP Alternatives ($1000) Alternative B-1 MHI+BFP B-2 FBI+CFG B-2-A FBI + ST B-2-B FBI + STG Operation Costs Power $1,629 $2,484 $53 $118 Labor $2,184 $2,151 $186 $373 Fuel Maintenance $1,827 $2,433 $284 $1,175 $0 $119 $0 $175 Odor control $0 $50 $0 $0 Chemicals $512 $1,122 $25 Total operating costs $25 $8,585 $7,266 $383 $691 Hauling And Disposal $594 $594 $0 $0 Total Annual Costs $9,179 $7,860 $383 $691 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 28 Table 9-15 Annual Costs and Revenues for Bissell Point WWTP Alternatives ($1000) Alternative B-1 MHI+BFP B-2 FBI+CFG B-2-A FBI + ST B-2-B FBI + STG Revenues Steam ($0) ($0) ($855) ($0) Power generation ($0) ($0) ($0) ($880) Total Annual Revenues ($0) ($0) ($855) ($880) Overall annual costs for the Lemay treatment facility are provided in Table 9-16 below. As shown, there are comparable annual costs for Alternatives L-1 and L-2 which summarize annual costs for operating MHIs and FBI’s respectively. Both alternatives use belt filter press dewatering. Costs for Alternative L-3 increase with centrifuge dewatering because of additional power and polymer use compared to the BFPs. Some of these costs are offset from revenue generated from steam sales or power generation, as summarized in Alternative L-1-A (for MHI’s) and Alternatives L-2 and l-3 (for FBI’s). Heat recovered and converted to steam for sale or power generation produces revenues that are similar for both types of incinerators, given the same solids feed and characteristics. Costs for hauling and disposal are the same for either major alternative for incineration and dewatering. Table 9-16 Annual Costs and Revenues for Lemay WWTP Alternatives ($1000) Alternative L-1 MHI +BFP L-2 FBI +BFP L-3 FBI +CFG L-1-A MHI +STG L-2&3-A FBI +STG Operation Costs Power $866 $1282 $1,720 $107 $107 Labor $1,689 $1,623 $1,623 $339 $339 Fuel Maintenance $723 $1,671 $298 $909 $82 $1,072 $0 $205 $0 $123 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 Reviewed by: W. Hoener 29 Table 9-16 Annual Costs and Revenues for Lemay WWTP Alternatives ($1000) Alternative L-1 MHI +BFP L-2 FBI +BFP L-3 FBI +CFG L-1-A MHI +STG L-2&3-A FBI +STG Odor Control $0 $0 $50 $0 $0 Chemicals $350 $350 $640 $25 Total operating costs $25 $5,299 $4,462 $5,190 $676 $594 Hauling And Disposal $396 $396 $396 $0 $0 Total Annual Costs $5,695 $4,858 $5,587 $676 $594 Revenues Steam ($0) ($0) ($0) ($0) ($0) Power generation ($0) ($0) ($0) ($429) ($432) Total Annual Revenues ($0) ($0) ($0) ($429) ($432) Table 9-17 provides a summary of the annual costs associated with alternatives considered for the Coldwater treatment facility. As shown in Alternative C-2, annual costs associated with hauling cake to a landfill rise are dramatically higher as compared to the existing alternative of discharging the solids into the collection system for the Bissell Point treatment facility. Alternative C-2 (base case) considers belt filter press dewatering. Alternatives C-2-A and C-2-B provide costs for centrifuge and rotary press dewatering in lieu of belt filter presses, and as shown, have significantly lower annual costs associated with them; primarily due to the differences in odor control that are required. Belt filter presses in this case are anticipated to have significantly greater odor control requirements. Alternative C-3 considers adding anaerobic digestion to the plant with belt filter presses used for dewatering. C-3-A and C-3-B show cost reductions with the use of centrifuges and rotary presses respectively. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 2009145 B&V File 44.000 30 Reviewed by: W. Hoener Table 9-17 Annual Costs and Revenues for Coldwater WWTP Alternatives ($1000) Alternative C-1 Current Operation C-2 Raw Cake to Landfill C-2-A CFG Dewatering C-2-B RP Dewatering C-3 Anaerobic Digestion C-3-A CFG Dewatering C-3-B RP Dewatering Operation Costs Power $121 $162 $190 $163 $436 $440 $434 Labor $37 $145 $145 $145 $431 $431 $431 Fuel $0 $0 $0 $0 $0 $0 $0 Maintenance $18 $208 $105 $101 $495 $388 $391 Chemicals $0 $81 $162 $162 $140 $239 $239 Digester Cleaning $0 $0 $0 $0 $26 $26 Total Operation Costs $26 $176 $596 $602 $571 $1,528 $1,524 $1,521 Hauling And Disposal $0 $898 $795 $795 $741 $630 $630 Total Annual Costs $176 $1,494 $1,397 $1,366 $2,269 $2,154 $2,151 Revenues Steam $0 $0 $0 $0 ($440) ($440) ($440) Power generation $0 $0 $0 $0 $0 $0 $0 Total Annual Revenues $0 $0 $0 $0 ($440) ($440) ($440) BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 31 Reviewed by: W. Hoener Annual costs for anaerobic digestion are considerably greater than either the current option (discharge into the Bissell Point collection system) or hauling cake solids to a landfill. However, there is an offset associated with revenues generated from the production of gas with this option of about $440,000 per year. Dewatering options associated with using centrifuges and rotary presses instead of belt filter presses result in a lower annual costs due to the reduction in odor control costs associated with the latter two alternatives. Annual costs associated with the Missouri River treatment facility are summarized in Table 9-18 for Alternative M-1, consisting of the current operation of anaerobic digestion with gas utilization equipment added; and Alternative M-2, consisting of anaerobic digestion with the addition of a FOG receiving station and co-digestion of the FOG with the plant’s biosolids. The table shows additional labor and maintenance associated with co-digestion alternative but the FOG facilities result in more revenue received from the additional gas generated (and used to produce power). The predominant contributor to annual cost for either of these options is the cake hauling costs, which are the same for both alternatives. When considering both annual costs and revenues, the alternatives are comparable for total net costs. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 32 Reviewed by: W. Hoener Table 9-18 Annual Costs and Revenues for Missouri River WWTP Alternatives ($1000) Alternative M-1 Current Operation w/ Additional CHP M-2 Co-digestion with FOG Operation Costs Power $852 $8162 Labor $117 $186 Fuel $0 $0 Maintenance $396 $442 Chemicals $673 $678 Total operating costs $2,102 $2,234 Hauling And Disposal $1,788 $1,788 Total Annual Costs $3,892 $4,022 Revenues Steam $0 $0 Power generation ($1,370) ($1,603) Total Annual Revenues ($1,495) ($1,750) Annual costs and revenues for the Lower Meramec treatment facility are summarized in Table 9- 19. Alternative LM-1 consists of co-thickening with digestion; while Alternative LM-2 considers separate thickening with anaerobic digestion. Costs for dewatering polymer were also included. Operating costs for Alternative LM-1 are approximately 15 percent lower Alternative LM-2. Revenues generated from energy produced from the digester gas generated are the same for both alternatives. The predominant factors for each alternative are the costs for hauling and disposal, which are the same. Consequently, the two alternatives result in relatively similar overall annual costs. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 33 Reviewed by: W. Hoener Table 9-19 Annual Costs and Revenues for Lower Meramec Plant Alternatives ($1000) Alternative LM-1 Co-thickening and Digestion LM-2 Separate Thickening and Digestion Operation Costs Power $331 $279 Labor $117 $215 Fuel $0 $0 Maintenance $387 $328 Chemicals $151 $207 Digester Cleaning $86 $82 Total operating costs $1,061 $1,180 Hauling And Disposal $1,129 $1,129 Total Annual Costs $2,190 $2,309 Revenues Steam $0 $0 Power generation ($537) ($537) Total Annual Revenues ($537) ($537) Table 9-20 summarizes annual costs associated with the Regional Facility for the primary option of an FBI system using centrifuge dewatering. Costs associated with steam production (and revenues generated) and power generation from steam are summarized as Alternatives R-1-A and R-1-B, respectively. As expected, the overall annual cost associated with processing solids for all of the District’s wastewater treatment facilities at one regional plant are quite high comparatively. However, revenues generated from the recovery of energy provide significant offsets, with steam sales providing a 75 percent greater return than power. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 34 Reviewed by: W. Hoener Table 9-20 Annual Costs and Revenues for the Regional Plant Alternatives ($1000) Alternative R-1 FBI+CFG R-1-A FBI + ST R-1-B FBI + STG Operation Costs Power $3,792 $130 $302 Labor $2,151 $186 $373 Fuel Maintenance $559 $1,684 $0 $220 $0 $287 Odor Control $3,300 $0 $0 Chemicals $1,273 $30 Total operating costs $30 $12,759 $566 $992 Hauling And Disposal $1,473 $0 $0 Total Annual Costs $14,232 $566 $992 Revenues Steam ($0) ($2,760) ($0) Power generation ($0) ($0) ($2,861) Total Annual Revenues ($0) ($2,760) ($2,861) For a better assessment of a regional facility located at the Bissell Point plant, additional comparisons were developed to provide an evaluation of a regional facility option to a de- centralized, no-regional option. The annual costs and revenues for these comparisons are provided in Table 9-21. The annual costs for these three systems are similar. Annual revenues from power generation from digester gas at two of the plants reduce the costs of the decentralized alternative. Regional Alternative S-2, which uses hauling of dewatered solids from Lemay to the regional facility is more cost effective than for Alternative S-3 which uses pumping liquid solids into the Bissell Point collection system. For the Regional alternatives, annual costs are approximately the same at $16 million, with the majority of this cost associated with the BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 35 Reviewed by: W. Hoener operation of odor control for the receiving facilities at regional facility. The remaining costs are associated with conveying (by pumping or hauling) solids from the remaining facilities to a regional facility located on the Bissell Point site. Additional information related to the regional alternative is provided in Appendix A. Table 9-21 Annual Costs and Revenues for the Regional Systems ($1000) Alternative Decentralized (No Regional) S-1 Regional Total System S-2 (Lemay Haul) Regional Total System S-3 (Lemay Pump) Operation Costs Power $5,564 $4,621 $4,476 Labor $4,045 $2,423 $2,765 Fuel $366 $558 $558 Maintenance $2,981 $1,816 $1,842 Odor Control $100 $3,350 $3,300 Digester Cleaning $153 $0 $0 Chemicals $2,590 $3,047 Total operating costs $2,630 $15,799 $15,815 $15,571 Hauling And Disposal $3,907 $4,294 $3,320 Total Annual Costs $19,706 $20,109 $18,891 Revenues Steam ($0) ($0) ($0) Power generation ($2,032) ($0) ($0) Total Annual Revenues ($2,032) ($0) ($0) BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 36 Reviewed by: W. Hoener 6. Overview of Alternatives Costs Overall present worth costs for each alternative were developed based on the following assumptions:  20 year life of project, salvage values as defined for capital costs  Five (5) percent interest rate  Project capital costs from Table 9-8 through Table 9-14 for the various plants and alternatives.  Annual costs and revenues from Table 9-15 through Table 9-21 for the various plants and alternatives Summaries of capital costs, annual costs and revenues, and present worth costs for all the alternatives and plants are presented in the following tables. Values from the tables presented in this TM are used in the Triple Bottom Line evaluations, as described in Technical Memorandum No. 10 Alternatives Selection Process and Results. Table 9-22 summarizes the present worth costs for the Bissell Point facility for the two primary alternatives of MHI incineration versus FBI incineration; with costs associated with energy recovery provided as additional costs to the primary FBI alternative. The capital cost and total present worth cost for alternative B-1 includes costs associated with a major re-build for the MHI equipment at year 10 of the project. Total present worth costs are approximately $214 million for the MHI alternative compared to the $272 million shown for the FBI base alternative. The cost difference reflects additional equipment costs for the new facility compared to reuse of existing equipment with fully amortized costs. Revenues associated with the recovery of steam provide significant offsets, but still result in an increase in the overall present worth costs. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 37 Reviewed by: W. Hoener Table 9-22 Summary of Cost Opinions for Bissell Plant Alternatives 1 ($1000) Alternative B-1 MHI+BFP B-2 FBI+CFG B-2-A FBI + ST B-2-B FBI + STG Capital Costs $100,284 $175,732 $15,559 $29,003 Salvage Value ($782) ($4,556) ($1,861) ($494) Annual O&M Costs $9,179 $7,860 $383 $691 Annual Revenue ($0) ($0) ($855) ($806) Present Worth Costs Capital $100,284 $175,732 $15,559 $29,003 Salvage ($295) ($1,717) ($701) ($186) O&M $114,393 $97,947 $4,773 $8,611 Revenue ($0) ($0) ($10,655) ($10,971) Total Present Worth Costs $214,382 $271,962 $8,976 $26,457 Table 9-23 summarizes the overall present worth costs for the Lemay treatment facility. Total present worth costs associated with the MHIs are approximately 80 percent of those for FBIs with existing belt filter press dewatering. The capital cost and total present worth cost for alternative L-1 includes costs associated with a major re-build for the MHI equipment at year 10 of the project. Replacement of the belt filter presses with centrifuges results in additional present BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 38 Reviewed by: W. Hoener worth costs. Addition of energy recovery for both MHI and FBI alternatives also increases the present worth costs. Table 9-23 Summary of Cost Opinions for Lemay Plant Alternatives 1 ($1000) Alternative L-1 MHI +BFP L-2 FBI +BFP L-3 FBI +CFG L-1-A MHI +STG L-2&3-A FBI +STG Capital Costs $76,135 $119,739 $144,853 $29,036 $24,223 Salvage Value ($3,093) ($2,625) ($3,616) ($494) ($494) Annual O&M Costs $5,695 $4,858 $5,587 $676 $644 Annual Revenue ($0) ($0) ($0) ($429) ($432) Present Worth Costs Capital $76,135 $119,739 $144,853 $29,036 $24,223 Salvage ($1,166) ($989) ($1,363) ($186) ($186) O&M $70,972 $60,536 $69,622 $8,424 $8,021 Revenue ($0) ($0) ($0) ($5,348) ($5,384) Total Present Worth Costs $145,941 $179,286 $213,112 $31,926 $26,056 1. See Technical Memorandum No. 2 for description of alternatives. Present worth costs for the Coldwater treatment facility are provided in Table 9-24. Alternative C-1 represents the lowest cost option with a present worth cost of $9M, followed by Alternative C-2 (hauling cake to a landfill) with a present worth cost of $36M using belt filter presses for dewatering. Present worth costs are reduced for Alternative 2 with centrifuge or rotary press dewatering. Alternative C-3 (anaerobic digestion with cake hauling) has the highest overall present cost at $54M. Again, as with Alternative C-2, digestion costs are offset with the utilization of centrifuge or rotary press dewatering in lieu of belt filter press dewatering (base case) due the reduced costs associated with odor control. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives May 17, 2011 MSD Contract No. 2009145 B&V File 44.000 39 Reviewed by: W. Hoener Table 9-24 Summary of Cost Opinions for Coldwater Plant Alternatives 1 ($1000) Alternative C-1 Current Operation C-2 Raw Cake to Landfill C-2-A CFG Dewatering C-2-B RP Dewatering C-3 Anaerobic Digestion C-3-A CFG Dewatering C-3-B RP Dewatering Capital Costs $6,868 $17,233 $16,191 $15,596 $31,636 $31,281 $30,977 Salvage ($601) ($401) ($401) ($401) ($584) ($584) ($584) Annual O&M Costs $176 $1,494 $1,397 $1,366 $2,269 $2,154 $2,151 Annual Revenue $0 $0 $0 $0 ($440) ($440) ($440) Present Worth Costs Capital $6,868 $17,233 $16,191 $15,596 $31,636 $31,281 $30,977 Salvage ($227) ($151) ($151) ($151) ($220) ($220) ($220) O&M $2,193 $18,619 $17,410 $17,024 $28,280 $26,847 $26,809 Revenue $0 $0 $0 $0 ($5,485) ($5,485) ($5,485) Total Present Worth Costs $8,830 $35,700 $33,450 $32,470 $54,210 $52,420 $50,080 1. See Technical Memorandum No. 3 for description of alternatives. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 40 Reviewed by: W. Hoener Overall present worth costs for the Missouri River Plant are summarized in Table 9-25. Alternative M-2 results in a higher capital cost with the inclusion of FOG facilities, but this is offset by the increased production of gas and power generation from the gas. Consequently, overall present worth costs for both options are comparable, differing by less than 2 percent. Table 9-25 Summary of Cost Opinions for Missouri River Plant Alternatives 1 ($1000) Alternative M-1 Current Operation w/ Additional CHP M-2 Co-digestion with FOG Capital Costs $2,686 $3,652 Salvage ($190) ($219) Annual O&M Costs $3,892 $4,022 Annual Revenue ($1,495) ($1,750) Present Worth Costs Capital $2,686 $3,652 Salvage ($72) ($83) O&M $48,508 $50,128 Revenue ($19,631) ($21,809) Total Present Worth Costs $32,490 $31,890 1. See Technical Memorandum No. 4 for description of alternatives. Present worth costs associated with the Lower Meramec treatment facility are shown in Table 9- 26 for Alternative LM-1 (consisting of co-thickening and digestion) and LM-2 (consisting of separate thickening and digestion). The Lower Meramec plant does not currently include BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 41 Reviewed by: W. Hoener anaerobic digestion, and as such, these facilities would result in a significant modification to the overall plant. Table 9-26 Summary of Cost Opinions for Lower Meramec Plant Alternatives 1 ($1000) Alternative LM-1 Co-thickening and Digestion LM-2 Separate Thickening and Digestion Capital Costs $40,553 $44,720 Salvage Value ($5,275) ($4,944) Annual O&M Costs $2,190 $2,309 Annual Revenue ($537) ($537) Present Worth Costs Capital $40,553 $44,720 Salvage ($1,988) ($1,863) O&M $27,292 $28,775 Revenue ($6,692) ($6,692 Total Present Worth Costs $59,170 $64,940 1. See Technical Memorandum No. 5 for description of alternatives. Present worth costs for the regional facility are shown in Table 9-27 with the primary alternative of an FBI system with centrifuge dewatering having a total cost of approximately $419 million. Additional alternatives for energy recovery and emission controls are also included. Alternative R-1-A with steam production and sale to Trigen (or another entity) results in the lowest overall present worth cost due to the revenues generated with this option. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 42 Reviewed by: W. Hoener Table 9-27 Summary of Cost Opinions for Regional Facility Alternatives 1 ($1000) Alternative R-1 FBI+CFG R-1-A FBI+ST R-1-B FBI+STG Capital Costs $244,432 $20,603 $41,215 Salvage Value ($7,075) ($1,106) ($791) Annual O&M Costs $14,232 $566 $992 Annual Revenue ($0) ($2,760) ($2,861) Present Worth Costs Capital $244,432 $20,603 $41,215 Salvage Value ($2,667) ($417) ($298) O&M $177,357 $7,054 $12,363 Revenue ($0) ($34,399) ($35,655) Total Present Worth Costs $419,122 ($7,159) $17,625 The overall present worth costs summary of a regional system versus a de-centralized system are provided in Table 9-28. As shown, the de-centralized alternative has the highest overall present worth cost associated with it. The lowest overall present worth cost consists of the regional concept where Lemay solids are hauled to the Bissell Point regional facility. Pumping of liquid from Lemay has additional present worth costs that increase the regional facility present worth costs. For the regional systems options, only the base case is considered with no revenue offsets are included for sale of steam or power generation. BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 43 Reviewed by: W. Hoener Table 9-28 Summary of Cost Opinions for the Regional Evaluation ($1000) Alternative Decentralized (No Regional) S-1 Regional Total System S-2 Regional Total System S-3 Capital Costs $366,785,000 $274,488,000 $316,143,000 Salvage Value ($10,626,000) ($9,034,000) ($15,875,000) Annual O&M Costs $20,362,000 $20,109,000 $17,182,000 Annual Revenue ($2,032,000) $0 $0 Present Worth Costs Capital $366,785,000 $274,488,000 $316,143,000 Salvage Value ($4,005,000) ($3,405,000) ($5,983,000) O&M $253,756,000 $250,603,000 $214,126,000 Revenue ($25,323,000) $0 $0 Total Present Worth Costs $591,213,000 $521,686,000 $524,286,000 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 44 Reviewed by: W. Hoener Update: Table 9-29 provides the update for the evaluation of a regional system alternatives assuming that the Mercury limit is relaxed to the point that the existing MHI’s would continue to function indefinitely. Equipment modifications for this option were summarized in Table 9-7. As shown, capital costs are reduced significantly in comparison to the costs shown in Table 9-28. O&M costs for S-4 and S-5 (compared to S-1 and S-2) are significantly higher however, such that the overall present worth costs for those two basic alternatives are reasonably close. Alternative S-6 represents the lowest overall present worth cost of the six alternatives. Table 9-29 Summary of Cost Opinions for the Regional Evaluation Assuming Relaxed Mercury Limits and Extending MHI Usage ($1000) Alternative Decentralized (No Regional) S-4 Regional Total System S-5 Regional Total System S-6 Capital Costs $251,057,750 $166,674,000 $242,959,000 Salvage Value ($3,289,000) ($701,000) ($2,187,000) Annual O&M Costs $26,278,000 $25,247,000 $20,911,000 Annual Revenue ($2,032,000) $0 $0 Present Worth Costs Capital $251,058,000 $166,674,000 $242,959,000 Salvage Value ($1,240,000) ($264,000) ($824,000) O&M $327,482,000 $314,633,000 $260,597,000 Revenue ($25,323,000) $0 $0 Total Present Worth Costs $551,977,000 $481,043,000 $502,732,000 BLACK & VEATCH St. Louis MSD Phase II B&V Project 165186 Opinions of Costs for Alternatives August 30, 2010 MSD Contract No. 200914 Updated: January 19, 2011 Final: May 17, 2011 B&V File 44.000 45 Reviewed by: W. Hoener Appendix A Summary of Cost Opinions for the Regional Systems Note: 1 Additional equipment needed but not included in the cost evaluation. Coldwater Thickening Gravity Thickening (New EQ) Force Main to Regional Facility Lower Meramec Thickening Gravity Thickening (New EQ & Tank) Dewatering1 BFP Cake Storage and Loadout to Disposal1 (New Extra Capacity) Lemay Thickening Gravity Thickening GBT Dewatering Centrifuge Bissell Point Thickening Gravity Thickening GBT Dewatering Centrifuge Incineration FBI (New) Ash Dewatering (Ash Lagoon, upgrade to slurry system) Ash Loadout MSD Decentralized Treatment System (S-1) Solids Handling Process Flow Chart MO River Thickening RDT Thickening Anaerobic Digestion Dewatering Centrifuge Cake Storage and Loadout to Disposal CHP (New EQ) End Use End Use Incineration FBI (New) Ash Dewatering (Ash Lagoon, upgrade to slurry system) End Use End Use Ash Loadout Anaerobic Digestion (New) CHP (New) Note: 1 Additional equipment needed but not included in the cost evaluation. Coldwater Thickening Gravity Thickening (New EQ) Force Main to Regional Facility Lower Meramec Thickening Gravity Thickening (New EQ & Tank) Dewatering1 BFP Cake Storage and Loadout to Disposal1 (New Extra Capacity) Lemay Thickening Gravity Thickening GBT Dewatering BFP Bissell Point Thickening Gravity Thickening GBT Dewatering BFP Incineration MHI (Existing) Ash Dewatering (Ash Lagoon, upgrade to slurry system) Ash Loadout MSD Decentralized Treatment System (S-4) Solids Handling Process Flow Chart MO River Thickening RDT Thickening (New EQ) Anaerobic Digestion Dewatering Centrifuge Cake Storage and Loadout to Disposal CHP (New EQ) End Use End Use Incineration MHI (Existing) Ash Dewatering (Ash Lagoon, upgrade to slurry system) End Use End Use Ash Loadout Anaerobic Digestion (New) CHP (New) Bissell Point Lemay Coldwater Mo. River Lower Meramec Total Alternatives CFG+2 FBI CFG+2 FBI PS+FM AD+DW AD+DW General General Requirements 7,184,000 5,212,000 386,000 131,000 1,977,000 14,890,000 Sitework 200,000 200,000 3,361,000 0 288,000 4,049,000 Structures Gravity Thickener 763,000 763,000 Thickening and Dewatering Building Digesters 8,306,000 8,306,000 Digester Building 2,037,000 2,037,000 Dewatering Building 4,128,000 4,128,000 8,256,000 Cake Loadout Building CHP Building 792,000 1,807,000 2,599,000 Incinerator Building 7,879,000 6,799,000 14,678,000 Sludge Receiving 2,160,000 2,160,000 Subtotal Structures 14,167,000$ 10,927,000$ -$ 792,000$ 12,913,000$ 38,799,000$ Equipment FOG receiving Cake Load Out Gravity Thickening Equipment 364,000 624,000 988,000 Mechanical Thickening Equipment Digester Equipment 4,949,000 4,949,000 Dewatering Equipment 8,704,000 8,574,000 17,278,000 Digester Gas Utilization 530,000 1,194,000 1,724,000 Incinerator Equipment 41,082,000 39,303,000 80,385,000 Sludge Receiving 0 Conveyance Equipment Odor Control 3,300,000 2,240,000 5,540,000 Pump Station 480,000 480,000 Subtotal Equipment 53,086,000$ 50,117,000$ 844,000$ 530,000$ 6,767,000$ 111,344,000$ Electrical 4,514,000 4,146,000 59,000 93,000 1,398,000 10,210,000 Instrumentation & Control 1,934,000 1,777,000 25,000 40,000 599,000 4,375,000 Subtotal 81,085,000 72,379,000 4,675,000 1,586,000 23,942,000 183,667,000 Contingencies 21,753,000 17,591,000 308,000 363,000 5,486,000 45,501,000 Mid-Point of Construction 11,148,000 9,015,000 511,000 200,000 3,016,000 23,890,000 TOTAL Construction Cost 113,986,000$ 98,985,000$ 5,494,000$ 2,149,000$ 32,444,000$ 253,058,000$ Engineering 29,978,000 24,242,000 1,374,000 537,000 8,111,000 64,242,000 Advanced Emission Control 25,843,000 23,642,000 49,485,000 TOTAL PROJECT COST 169,807,000$ 146,869,000$ 6,868,000$ 2,686,000$ 40,555,000$ $366,785,000 Salvage 10,626,000$ Final Printed:10/20/2011 14:53 MSD Decentralized Treatment System (S-1) Solids Handling Process Capital Costs MSD Decentralized Treatment System (S-4) Solids Handling Process Capital Costs Bissell Point Lemay Coldwater Mo. River Lower Meramec Total Alternatives BFP+ 4 MHIs BFP+ 3 MHIs PS+FM AD+DW AD+DW General General Requirements 3,892,000 1,418,000 386,000 131,000 1,977,000 7,804,000 Sitework 200,000 225,000 3,361,000 0 288,000 4,074,000 Structures Gravity Thickener 763,000 763,000 Thickening and Dewatering Building Digesters 8,306,000 8,306,000 Digester Building 2,037,000 2,037,000 Dewatering Building 0 0 0 Cake Loadout Building CHP Building 792,000 1,807,000 2,599,000 Incinerator Building 0 0 0 Sludge Receiving 0 0 Subtotal Structures -$ -$ -$ 792,000$ 12,913,000$ 13,705,000$ Equipment FOG receiving Cake Load Out Gravity Thickening Equipment 364,000 624,000 988,000 Mechanical Thickening Equipment Digester Equipment 0 4,949,000 4,949,000 Dewatering Equipment 0 0 0 Digester Gas Utilization 530,000 1,194,000 1,724,000 Incinerator Equipment 13,637,000 10,478,000 24,115,000 Sludge Receiving 0 0 Conveyance Equipment 0 0 Odor Control 3,300,000 0 3,300,000 Pump Station 480,000 480,000 Subtotal Equipment 16,937,000$ 10,478,000$ 844,000$ 530,000$ 6,767,000$ 35,556,000$ Electrical 2,752,000 1,070,000 59,000 93,000 1,398,000 5,372,000 Instrumentation & Control 1,179,000 428,000 25,000 40,000 599,000 2,271,000 Subtotal 24,960,000 13,619,000 4,675,000 1,586,000 23,942,000 68,782,000 Contingencies 11,784,000 3,405,000 308,000 363,000 5,486,000 21,346,000 Mid-Point of Construction 6,039,000 1,745,000 511,000 200,000 3,016,000 11,511,000 TOTAL Construction Cost 42,783,000$ 18,769,000$ 5,494,000$ 2,149,000$ 32,444,000$ 101,639,000$ Engineering 10,695,750 4,692,000 1,374,000 537,000 8,111,000 25,409,750 Advanced Emission Control 33,318,000 30,535,000 63,853,000 Rebuild MHIs in year 10 32,194,000 22,690,000 54,884,000 Sludge Loadout 5,272,000 TOTAL PROJECT COST 118,990,750$ 81,958,000$ 6,868,000$ 2,686,000$ 40,555,000$ $251,057,750 Salvage $0 $0 $0 $190,000 $3,099,000 3,289,000$ Final Printed:10/20/2011 14:53 MSD Decentralized Treatment System (S-4) Solids Handling Process Capital Costs Bissell Point Lemay Coldwater Mo. River Lower Meramec Total Alternatives CFG+FBI CFG+FBI PS+FM AD+DW AD+DW Power 2,484,000$ 1,720,000$ 121,000$ 852,000$ 387,000$ 5,564,000$ Fuel - Natural Gas 267,000 76,000 343,000 Fuel Oil 17,000 5,500 22,500 Other - Subtotal 284,000$ 81,500$ -$ -$ -$ 365,500$ Labor - Operations 1,179,000 786,000 33,000 66,000 66,000 2,130,000 Maintenance 666,000 400,000 4,000 33,000 33,000 1,136,000 Supervisor 306,000 306,000 18,000 18,000 648,000 Stationary Engineer - Other - Subtotal 2,151,000$ 1,492,000$ 37,000$ 117,000$ 117,000$ 3,914,000$ Maintenance - Equipment 1,175,000 1,671,000 18,000 396,000 320,000 3,580,000 Subtotal 1,175,000$ 1,671,000$ 18,000$ 396,000$ 320,000$ 3,580,000$ Chemicals - Polymer 1,024,000 294,000 673,000 151,000 2,142,000 Sodium Permanganate (OC)- Powdered Activated Carbon 98,000 56,000 154,000 Water treatment - Other - Subtotal 1,122,000$ 350,000$ -$ 673,000$ 151,000$ 2,296,000$ Digester Cleaning - Digester Cleaning 24,000 41,000 65,000 Digester Painting 8,000 10,000 18,000 Membrane Cover Replacement 35,000 35,000 70,000 Subtotal -$ 67,000$ 86,000$ 153,000$ Transportation and Disposal - Hauling Fee 594,000 775,000 426,000 411,000 2,206,000 Landfill Tip Fee 41,000 1,362,000 718,000 2,121,000 Land Application Fee -- Ash lagoon cleanout 62,000 62,000 Subtotal 594,000$ 878,000$ -$ 1,788,000$ 1,129,000$ 4,389,000$ Odor Control 50,000 50,000 100,000 Total Annual Costs 7,860,000$ 6,243,000$ 176,000$ 3,893,000$ 2,190,000$ 20,362,000$ - ANNUAL REVENUE ($ per annum)- - Power - ($1,495,000)($537,000)($2,032,000) Steam - - - - Hot Water - - - - Digester gas - - - - Dried pellets - - - - Other - - - - Total Annual Revenues $0 $0 $0 ($1,495,000)($537,000)($2,032,000) Printed:10/20/2011 14:53 MSD Decentralized Treatment System (S-1) Solids Handling Process O&M Costs Bissell Point Lemay Coldwater Mo. River Lower Meramec Total Alternatives BFP + 4 MHIs BFP+ 3 MHIs PS+FM AD+DW AD+DW Power 2,609,000$ 1,154,000$ 121,000$ 852,000$ 387,000$ 5,123,000$ Fuel - Natural Gas 2,741,000 723,000 3,464,000 Fuel Oil - - - Other - Subtotal 2,741,000$ 723,000$ -$ -$ -$ 3,464,000$ Labor - Operations 1,310,000 786,000 33,000 66,000 66,000 2,261,000 Maintenance 699,000 466,000 4,000 33,000 33,000 1,235,000 Supervisor 306,000 306,000 18,000 18,000 648,000 Stationary Engineer - Other - Subtotal 2,315,000$ 1,558,000$ 37,000$ 117,000$ 117,000$ 4,144,000$ Maintenance - Equipment 2,572,000 2,359,000 18,000 396,000 320,000 5,665,000 Subtotal 2,572,000$ 2,359,000$ 18,000$ 396,000$ 320,000$ 5,665,000$ Chemicals - Polymer 1,529,000 294,000 673,000 151,000 2,647,000 Sodium Permanganate (OC)50,000 29,000 79,000 Powdered Activated Carbon 98,000 56,000 154,000 Water treatment - Other - Subtotal 1,677,000$ 379,000$ -$ 673,000$ 151,000$ 2,880,000$ Digester Cleaning - Digester Cleaning 24,000 41,000 65,000 Digester Painting 8,000 10,000 18,000 Membrane Cover Replacement 35,000 35,000 70,000 Subtotal -$ 67,000$ 86,000$ 153,000$ Transportation and Disposal - Hauling Fee 810,000 775,000 426,000 411,000 2,422,000 Landfill Tip Fee 41,000 1,362,000 718,000 2,121,000 Land Application Fee - Ash lagoon cleanout 194,000 62,000 256,000 Subtotal 1,004,000$ 878,000$ -$ 1,788,000$ 1,129,000$ 4,799,000$ Odor Control 50,000 50,000 Total Annual Costs 12,968,000$ 7,051,000$ 176,000$ 3,893,000$ 2,190,000$ 26,278,000$ - ANNUAL REVENUE ($ per annum)- - Power - ($1,495,000)($537,000)($2,032,000) Steam - - - - Hot Water - - - - Digester gas - - - - Dried pellets - - - - Other - - - - Total Annual Revenues $0 $0 $0 ($1,495,000)($537,000)($2,032,000) Printed:10/20/2011 14:53 MSD Decentralized Treatment System (S-4) Solids Handling Process O&M Costs Note: 1 Additional equipment needed but not included in the cost evaluation. Coldwater Thickening Gravity Thickening Force Main to Regional Facility (New PS & FM) MO River Thickening RDT Thickening Dewatering Centrifuge Cake Storage and Loadout to Regional Facility Lower Meramec Thickening Gravity Thickening (New EQ & Tanks) Dewatering1 BFP Cake Storage and Loadout to Regional Facility1 Lemay Thickening Gravity Thickening GBT Dewatering BFP (Existing) Cake Storage and Loadout to Regional Facility Bissell Point Thickening Gravity Thickening GBT Dewatering Centrifuge (New) Dewatered Sludge Receiving (New) Incineration FBI (New) Regional Facility Ash Dewatering (New) Ash Loaddout MSD Regional System (S-2) Solids Treatment Process Flow Chart - Hauling Cake from Lemay Note: 1 Additional equipment needed but not included in the cost evaluation. Coldwater Thickening Gravity Thickening Force Main to Regional Facility (New PS & FM) MO River Thickening RDT Thickening Dewatering Centrifuge Cake Storage and Loadout to Regional Facility Lower Meramec Thickening Gravity Thickening (New EQ & Tanks) Dewatering1 BFP Cake Storage and Loadout to Regional Facility1 Lemay Thickening Gravity Thickening GBT Dewatering BFP (Existing) Cake Storage and Loadout to Regional Facility Bissell Point Thickening Gravity Thickening GBT Dewatering BFP (Existing) Dewatered Sludge Receiving (New) Incineration FBI (New) Regional Facility Ash Dewatering (New) Ash Loaddout MSD Regional System (S-5) Solids Treatment Process Flow Chart - Hauling Cake from Lemay Bissell Point Lemay Coldwater Mo. River Lower Meramec Regional Total Alternatives (See Regional)CFG+Loadout PS+FM DW DW ( 3 FBIs @Bissell) General General Requirements 0 1,173,000 386,000 9,900 156,800 9,901,000 11,626,700 Sitework 200,000 3,361,000 0 95,000 315,000 3,971,000 Structures Gravity Thickener 764,000 764,000 Thickening and Dewatering Building Digesters Digester Building Dewatering Building 4,128,000 4,128,000 Cake Loadout Building CHP Building Incinerator Building 0 7,052,000 7,052,000 Sludge Receiving 2,160,000 2,160,000 Subtotal Structures -$ 4,128,000$ -$ -$ 764,000$ 9,212,000$ 14,104,000$ Equipment FOG receiving Cake Load Out Gravity Thickening Equipment 364,000 624,000 988,000 Mechanical Thickening Equipment Digester Equipment Dewatering Equipment 8,574,000 8,574,000 Digester Gas Utilization Incinerator Equipment 0 0 65,509,000 65,509,000 Sludge Receiving 8,895,000 Conveyance Equipment Odor Control 424,000 100,000 100,000 3,300,000 3,924,000 Pump Station 480,000 480,000 Subtotal Equipment -$ 8,998,000$ 844,000$ 100,000$ 724,000$ 77,704,000$ 88,370,000$ Electrical 0 933,000 59,000 7,000 111,000 7,000,000 8,110,000 Instrumentation & Control 0 400,000 25,000 3,000 47,000 3,000,000 3,475,000 Subtotal 0 15,832,000 4,675,000 119,900 1,897,800 107,132,000 129,656,700 Contingencies 0 3,958,000 308,000 27,500 435,000 29,977,000 34,705,500 Mid-Point of Construction 0 2,028,000 511,000 15,100 239,000 15,363,000 18,156,100 TOTAL Construction Cost -$ 21,818,000$ 5,494,000$ 162,500$ 2,571,800$ 152,472,000$ 182,518,300$ Engineering 0 5,455,000 1,374,000 40,600 643,000 41,312,000 48,824,600 Advanced Emission Control 37,873,000 37,873,000 Sludge Loadout 5,272,000 TOTAL PROJECT COST -$ 32,545,000$ 6,868,000$ 203,000$ 3,215,000$ 231,657,000$ 274,488,000$ Salvage 9,034,000$ Final Printed:10/20/2011 14:53 MSD Regional System (S-2) Solids Handling Process- Capital Costs - Hauling Cake from Lemay Bissell Point Lemay Coldwater Mo. River Lower Meramec Regional Total Alternatives BFP + 5 MHIs BFP+Loadout PS+FM DW DW General General Requirements 0 475,000 386,000 9,900 156,800 2,622,000 3,649,700 Sitework 0 3,361,000 0 95,000 200,000 3,656,000 Structures Gravity Thickener 764,000 764,000 Thickening and Dewatering Building Digesters Digester Building Dewatering Building 0 0 0 Cake Loadout Building CHP Building Incinerator Building 0 0 0 Sludge Receiving 2,160,000 2,160,000 Subtotal Structures -$ -$ -$ -$ 764,000$ 2,160,000$ 2,924,000$ Equipment FOG receiving Cake Load Out Gravity Thickening Equipment 364,000 624,000 988,000 Mechanical Thickening Equipment Digester Equipment Dewatering Equipment 0 0 0 Digester Gas Utilization Incinerator Equipment 0 0 17,524,000 17,524,000 Sludge Receiving 8,895,000 Conveyance Equipment 1,260,000 Odor Control 424,000 100,000 100,000 3,300,000 3,924,000 Pump Station 480,000 480,000 Subtotal Equipment -$ 424,000$ 844,000$ 100,000$ 724,000$ 30,979,000$ 33,071,000$ Electrical 0 16,000 59,000 7,000 111,000 3,334,000 3,527,000 Instrumentation & Control 0 7,000 25,000 3,000 47,000 1,334,000 1,416,000 Subtotal 0 922,000 4,675,000 119,900 1,897,800 40,629,000 48,243,700 Contingencies 0 181,000 308,000 27,500 435,000 10,157,000 11,108,500 Mid-Point of Construction 0 93,000 511,000 15,100 239,000 4,772,000 5,630,100 TOTAL Construction Cost -$ 1,196,000$ 5,494,000$ 162,500$ 2,571,800$ 55,558,000$ 64,982,300$ Engineering 0 249,000 1,374,000 40,600 643,000 13,890,000 16,196,600 Advanced Emission Control 0 0 39,981,000 39,981,000 Rebuild 5 MHIs in year 10 0 40,242,000 40,242,000 Sludge Loadout 5,272,000 TOTAL PROJECT COST -$ 6,717,000$ 6,868,000$ 203,000$ 3,215,000$ 149,671,000$ 166,674,000$ Salvage $0 $0 $0 $0 $183,000 $518,000 701,000$ Final Printed:10/20/2011 14:53 MSD Regional System (S-5) Solids Handling Process- Capital Costs - Hauling Cake from Lemay Bissell Point Lemay Coldwater Mo. River Lower Meramec Regional Total Alternatives CFG + FBI BFP + Loadout PS+FM DW DW Power -$ 199,000$ 121,000$ -$ 15,000$ 3,792,000$ 4,127,000$ Fuel Natural Gas 533,000 533,000 Fuel Oil 25,000 25,000 Other - - Subtotal -$ -$ -$ -$ -$ 558,000$ 558,000$ Labor Operations 524,000 33,000 8,000 1,179,000 1,744,000 Maintenance 333,000 4,000 4,000 666,000 1,007,000 Supervisor 306,000 306,000 612,000 Stationary Engineer - Other - Subtotal -$ 1,163,000$ 37,000$ -$ 12,000$ 2,151,000$ 3,363,000$ Maintenance Equipment 909,000 18,000 14,000 1,684,000 2,625,000 Subtotal -$ 909,000$ 18,000$ -$ 14,000$ 1,684,000$ 2,625,000$ Chemicals Polymer 294,000 461,000 112,000 1,024,000 1,891,000 Sodium Permanganate (OC)29,000 116,000 80,000 225,000 Powdered Activated Carbon 154,000 154,000 Water treatment - Other - Subtotal -$ 323,000$ -$ 577,000$ 192,000$ 1,178,000$ 2,270,000$ Transportation and Disposal Hauling Fee 2,630,000 1,185,000 662,000 594,000 5,071,000 Landfill Tip Fee - Land Application Fee - Ash lagoon cleanout - Subtotal -$ 2,630,000$ -$ 1,185,000$ 662,000$ 594,000$ 5,071,000$ Odor Control 50,000 330,000 380,000 Total Annual Costs -$ 5,274,000$ 176,000$ 1,762,000$ 895,000$ 10,287,000$ 18,394,000$ ANNUAL REVENUE ($ per annum) Power - - - - - Steam - - - - - Hot Water - - - - - Digester gas - - - - - Dried pellets - - - - - Other - - - - - Total Annual Revenues -$ -$ -$ -$ -$ -$ -$ Printed:10/20/2011 14:53 MSD Regional System (S-2) Solids Handling Process O&M Costs - Hauling Cake from Lemay Bissell Point Lemay Coldwater Mo. River Lower Meramec Regional Total Alternatives BFP + 5 MHIs BFP + Loadout PS+FM DW DW (Bissell) (AEC for MHIs) Power 394,000$ 199,000$ 121,000$ -$ 15,000$ 3,228,000$ 3,957,000$ Fuel Natural Gas 3,654,000 3,654,000 Fuel Oil - - Other - - Subtotal -$ -$ -$ -$ -$ 3,654,000$ 3,654,000$ Labor Operations 131,000 524,000 33,000 8,000 1,572,000 2,268,000 Maintenance 67,000 333,000 4,000 4,000 966,000 1,374,000 Supervisor 306,000 306,000 612,000 Stationary Engineer - Other - Subtotal 198,000$ 1,163,000$ 37,000$ -$ 12,000$ 2,844,000$ 4,254,000$ Maintenance Equipment 113,000 1,011,000 18,000 14,000 2,552,000 3,708,000 Subtotal 113,000$ 1,011,000$ 18,000$ -$ 14,000$ 2,552,000$ 3,708,000$ Chemicals Polymer 294,000 461,000 112,000 2,047,000 2,914,000 Sodium Permanganate (OC)29,000 116,000 80,000 50,000 275,000 Powdered Activated Carbon 98,000 56,000 154,000 Water treatment - Other - Subtotal 98,000$ 323,000$ -$ 577,000$ 192,000$ 2,153,000$ 3,343,000$ Transportation and Disposal Hauling Fee 2,630,000 1,185,000 662,000 1,085,000 5,562,000 Landfill Tip Fee - Land Application Fee - Ash lagoon cleanout 389,000 389,000 Subtotal -$ 2,630,000$ -$ 1,185,000$ 662,000$ 1,474,000$ 5,951,000$ Odor Control 50,000 330,000 380,000 Total Annual Costs 803,000$ 5,376,000$ 176,000$ 1,762,000$ 895,000$ 16,235,000$ 25,247,000$ ANNUAL REVENUE ($ per annum) Power - - - - - Steam - - - - - Hot Water - - - - - Digester gas - - - - - Dried pellets - - - - - Other - - - - - Total Annual Revenues -$ -$ -$ -$ -$ -$ -$ Printed:10/20/2011 14:53 MSD Regional System (S-5) Solids Handling Process O&M Costs - Hauling Cake from Lemay Note: 1 Additional equipment needed but not included in the cost evaluation. Coldwater Thickening Gravity Force Main to Regional Facility MO River Thickening RDT Thickening Dewatering Centrifuge Cake Storage and Loadout to Regional Facility Lower Meramec Thickening Gravity Thickening (New EQ & Tanks) Dewatering1 BFP (New Add. EQ) Cake Storage and Loadout to Regional Facility1 Lemay Thickening Gravity Thickening Bissell Point Thickening Gravity Thickening Dewatering Centrifuge (New) Dewatered Sludge Receiving (New) Incineration FBI (New) Regional Facility Ash Dewatering (New) Ash Loaddout MSD Regional System (S-3) Solids Treatment Process Flow Chart - Pumping Sludge from Lemay Force Main to Regional Facility (New PS & FM) Note: 1 Additional equipment needed but not included in the cost evaluation. Coldwater Thickening Gravity Force Main to Regional Facility MO River Thickening RDT Thickening Dewatering Centrifuge Cake Storage and Loadout to Regional Facility Lower Meramec Thickening Gravity Thickening (New EQ & Tanks) Dewatering1 BFP (New Add. EQ) Cake Storage and Loadout to Regional Facility1 Lemay Thickening Gravity Thickening Bissell Point Thickening Gravity Thickening Dewatering Centrifuge (New) Dewatered Sludge Receiving (New) Incineration FBI (New) Regional Facility Ash Dewatering (New) Ash Loaddout MSD Regional System (S-6) Solids Treatment Process Flow Chart - Pumping Sludge from Lemay Force Main to Regional Facility (New PS & FM) Bissell Point Lemay Coldwater Mo. River Lower Meramec Regional Total Alternatives CFG +3 FBIs PS+FM PS+FM DW DW (Bissell) General General Requirements 0 2,905,000 386,000 9,900 156,800 10,490,000 13,947,700 Sitework 29,957,000 3,361,000 0 95,000 315,000 33,728,000 Structures Gravity Thickener 764,000 764,000 Thickening and Dewatering Building Digesters Digester Building Dewatering Building 6,191,000 6,191,000 Cake Loadout Building CHP Building Incinerator Building 0 7,052,000 7,052,000 Sludge Receiving 2,160,000 2,160,000 Subtotal Structures -$ -$ -$ -$ 764,000$ 15,403,000$ 16,167,000$ Equipment FOG receiving Cake Load Out Gravity Thickening Equipment 364,000 624,000 988,000 Mechanical Thickening Equipment Digester Equipment Dewatering Equipment 13,190,000 13,190,000 Digester Gas Utilization Incinerator Equipment 0 65,509,000 65,509,000 Sludge Receiving 8,895,000 Conveyance Equipment Odor Control 0 100,000 100,000 3,300,000 3,500,000 Pump Station 2,316,000 480,000 2,796,000 Subtotal Equipment -$ 2,316,000$ 844,000$ 100,000$ 724,000$ 90,894,000$ 94,878,000$ Electrical 0 0 59,000 7,000 111,000 7,417,000 7,594,000 Instrumentation & Control 0 0 25,000 3,000 47,000 3,179,000 3,254,000 Subtotal 0 35,178,000 4,675,000 119,900 1,897,800 127,698,000 169,568,700 Contingencies 0 0 308,000 27,500 435,000 31,760,000 32,530,500 Mid-Point of Construction 0 3,606,000 511,000 15,100 239,000 16,277,000 20,648,100 TOTAL Construction Cost -$ 38,784,000$ 5,494,000$ 162,500$ 2,571,800$ 175,735,000$ 222,747,300$ Engineering 0 9,696,000 1,374,000 40,600 643,000 43,769,000 55,522,600 Advanced Emission Control 37,873,000 37,873,000 TOTAL PROJECT COST -$ 48,480,000$ 6,868,000$ 203,000$ 3,215,000$ 257,377,000$ $316,143,000 Salvage 7,832,000$ 601,000$ 367,000$ 7,075,000$ 15,875,000$ Final Printed:10/20/2011 14:53 MSD Regional System (S-3) Solids Handling Process Capital Costs - Pumping Sludge from Lemay Bissell Point Lemay Coldwater Mo. River Lower Meramec Regional Total Alternatives BFP + 5 MHIs PS+FM PS+FM DW DW (AEC for MHIs) General General Requirements 0 2,905,000 386,000 9,900 156,800 2,622,000 6,079,700 Sitework 29,957,000 3,361,000 0 95,000 200,000 33,613,000 Structures Gravity Thickener 764,000 764,000 Thickening and Dewatering Building Digesters Digester Building Dewatering Building 6,191,000 6,191,000 Cake Loadout Building CHP Building Incinerator Building 0 0 0 Sludge Receiving 2,160,000 2,160,000 Subtotal Structures -$ -$ -$ -$ 764,000$ 8,351,000$ 9,115,000$ Equipment FOG receiving Cake Load Out Gravity Thickening Equipment 364,000 624,000 988,000 Mechanical Thickening Equipment Digester Equipment Dewatering Equipment 13,190,000 13,190,000 Digester Gas Utilization Incinerator Equipment 0 17,524,000 17,524,000 Sludge Receiving 8,895,000 Conveyance Equipment 1,260,000 Odor Control 100,000 100,000 3,300,000 3,500,000 Pump Station 2,316,000 480,000 2,796,000 Subtotal Equipment -$ 2,316,000$ 844,000$ 100,000$ 724,000$ 44,169,000$ 48,153,000$ Electrical 0 0 59,000 7,000 111,000 5,272,000 5,449,000 Instrumentation & Control 0 0 25,000 3,000 47,000 2,109,000 2,184,000 Subtotal 0 35,178,000 4,675,000 119,900 1,897,800 62,723,000 104,593,700 Contingencies 0 0 308,000 27,500 435,000 15,681,000 16,451,500 Mid-Point of Construction 0 3,606,000 511,000 15,100 239,000 4,772,000 9,143,100 TOTAL Construction Cost -$ 38,784,000$ 5,494,000$ 162,500$ 2,571,800$ 83,176,000$ 130,188,300$ Engineering 0 9,696,000 1,374,000 40,600 643,000 20,794,000 32,547,600 Advanced Emission Control 0 39,981,000 39,981,000 Rebuild 5 MHIs in year 10 0 40,242,000 40,242,000 Sludge Loadout 0 0 0 TOTAL PROJECT COST -$ 48,480,000$ 6,868,000$ 203,000$ 3,215,000$ 184,193,000$ $242,959,000 Salvage $0 $0 $0 $0 $183,000 $2,004,000 2,187,000$ Final Printed:10/20/2011 14:53 MSD Regional System (S-6) Solids Handling Process Capital Costs - Pumping Sludge from Lemay Bissell Point Lemay Coldwater Mo. River Lower Meramec Regional Total Alternatives CFG +FBIs PS+FM PS+FM DW DW Power -$ 233,000$ 121,000$ -$ 15,000$ 4,190,000$ 4,559,000$ Fuel Natural Gas 533,000 533,000 Fuel Oil 25,000 25,000 Other - - Subtotal -$ -$ -$ -$ -$ 558,000$ 558,000$ Labor Operations 524,000 33,000 8,000 1,507,000 2,072,000 Maintenance 333,000 4,000 4,000 866,000 1,207,000 Supervisor 306,000 306,000 612,000 Stationary Engineer - Other - Subtotal -$ 1,163,000$ 37,000$ -$ 12,000$ 2,679,000$ 3,891,000$ Maintenance Equipment 1,072,000 18,000 14,000 1,764,000 2,868,000 Subtotal -$ 1,072,000$ 18,000$ -$ 14,000$ 1,764,000$ 2,868,000$ Chemicals Polymer 461,000 112,000 1,612,000 2,185,000 Sodium Permanganate (OC)116,000 80,000 196,000 Powdered Activated Carbon 154,000 154,000 Water treatment - Other - Subtotal -$ -$ -$ 577,000$ 192,000$ 1,766,000$ 2,535,000$ Transportation and Disposal Hauling Fee 1,185,000 662,000 594,000 2,441,000 Landfill Tip Fee - Land Application Fee - Ash lagoon cleanout - Subtotal -$ -$ -$ 1,185,000$ 662,000$ 594,000$ 2,441,000$ Odor Control 330,000 330,000 Total Annual Costs -$ 2,468,000$ 176,000$ 1,762,000$ 895,000$ 11,881,000$ 17,182,000$ ANNUAL REVENUE ($ per annum) Power - - - - - Steam - - - - - Hot Water - - - - - Digester gas - - - - - Dried pellets - - - - - Other - - - - - Total Annual Revenues -$ -$ -$ -$ -$ -$ -$ Printed:10/20/2011 14:53 MSD Regional System (S-3) Solids Handling Process O&M Costs - Pumping Sludge from Lemay Bissell Point Lemay Coldwater Mo. River Lower Meramec Regional Total Alternatives BFP + 5 MHIs PS+FM PS+FM DW DW (Bissell) (AEC for MHIs) Power 394,000$ 233,000$ 121,000$ -$ 15,000$ 2,813,000$ 3,576,000$ Fuel Natural Gas 3,654,000 3,654,000 Fuel Oil - - Other - - Subtotal -$ -$ -$ -$ -$ 3,654,000$ 3,654,000$ Labor Operations 131,000 524,000 33,000 8,000 1,572,000 2,268,000 Maintenance 67,000 333,000 4,000 4,000 966,000 1,374,000 Supervisor 306,000 306,000 612,000 Stationary Engineer - Other - Subtotal 198,000$ 1,163,000$ 37,000$ -$ 12,000$ 2,844,000$ 4,254,000$ Maintenance Equipment 113,000$ 32,000$ 2,625,000$ 2,770,000$ Structures 60,000 18,000 14,000 92,000 Subtotal -$ 92,000$ 18,000$ -$ 14,000$ 2,625,000$ 2,862,000$ Chemicals Polymer - 461,000 112,000 2,047,000 2,620,000 Sodium Permanganate (OC)116,000 80,000 50,000 246,000 Powdered Activated Carbon 49,000 49,000 Water treatment - Other - Subtotal 49,000$ -$ -$ 577,000$ 192,000$ 2,097,000$ 2,915,000$ Transportation and Disposal Hauling Fee 1,185,000 662,000 1,084,000 2,931,000 Landfill Tip Fee - Land Application Fee - Ash lagoon cleanout 389,000 389,000 Subtotal -$ -$ -$ 1,185,000$ 662,000$ 1,473,000$ 3,320,000$ Odor Control 330,000 330,000 Total Annual Costs 754,000$ 1,488,000$ 176,000$ 1,762,000$ 895,000$ 15,836,000$ 20,911,000$ ANNUAL REVENUE ($ per annum) Power - - - - - Steam - - - - - Hot Water - - - - - Digester gas - - - - - Dried pellets - - - - - Other - - - - - Total Annual Revenues -$ -$ -$ -$ -$ -$ -$ Printed:10/20/2011 14:53 MSD Regional System (S-6) Solids Handling Process O&M Costs - Pumping Sludge from Lemay Appendix G – Grand Glaize Sludge Odor Reduction Study Section 6.Long-Term Alternatives 6.1 Anaerobic Digestion at Grand Glaize and Lower Meramec The addition of high-rate mesophilic anaerobic digestion of combined, thickened primary solids and WAS at both Grand Glaize and Lower Meramec is herein referred to as the on-site alternative. New WAS thickening facilities are also included at both WWTFs, based on the assumption that nutrient removal improvements at each facility will include biological phosphorus removal and the conversion of the existing gravity thickeners to a unified fermentation and thickening process for primary solids. Planning level conceptual designs, costs and site layouts were developed for each WWTF. A common concept design approach was applied to each WWTF, summarized as follows. ””New WAS thickening is based on the use of rotary drum thickeners (RDTs), as are currently used at the Missouri River WWTF. RDTs are sized for a 24 hour/day, 7 days/week thickening schedule and maximum month WAS production with one RDT unit out of service. RDTs and ancillary equipment, including a WAS feed pump, polymer blending and feed system, and a thickened WAS pump for each RDT train, are housed in a single-level, at-grade building. ”New anaerobic digestion facilities include digesters and associated process equipment. Digesters are sized to provide a minimum hydraulic retention time (HRT) of 15 days at maximum month thickened solids production with one digester out of service. An average volatile solids destruction of 50% is assumed, which meets Class B vector attraction reduction requirements. The 50% volatile solids reduction is a reasonable assumption based on the relatively high ratio of primary solids to WAS estimated for both facilities (with PS/WAS ratios ranging from 70/30 at Grand Glaize to 60/40 at Lower Meramec). ”Digesters are configured to operate under normal conditions, with all units in service, in a primary-secondary mode with one secondary digester, and as a primary-only mode when one digester is out of service. Digester construction is based on cast-in- place concrete with a fixed concrete cover. Digestion equipment includes for each digester one linear motion mixer, one digester feed pump, one digester recirculation pump and heat exchanger, and one digested solids transfer pump. Piping would be interconnected to allow pumps and heat exchangers to be shared between two digesters, in lieu of adding stand-by equipment. Digester heating is provided by shared digester gas-fired hot water boilers, including one stand-by boiler. Digester equipment is housed in a new two-level, at-grade digester building. Metropolitan St. Louis Sewer District 59 Grand Glaize Sludge Odor (12725) 01/26/18 ””Digester gas production is estimated at 16 cubic feet/lb VS destroyed. Digester gas energy content is assumed to be 600 BTU/cubic feet, typical for anaerobic digestion of WWTF solids. Digester gas is used at both facilities for digester heating. Digester gas flares, sized for the full gas production and including one stand-by unit, are provided. Combined heat and power (CHP) and associated digester gas treatment or digester gas treatment for renewable natural gas are not included for this evaluation, but could be considered as an option should on-site digestion be pursued further. The potential power production from digester gas-fired CHP has been estimated for future reference. Capital and operations and maintenance costs were developed for the on-site alternative. Capital costs include construction costs, developed consistent with those developed under the on-going Nutrient Removal Master Plan effort, and total project costs including engineering, administrative and legal services. Operations and maintenance costs include power demands and equipment maintenance for new WAS thickening and digestion facilities, WAS thickening polymer, and hauling and disposition of digested dewatered solids. For this evaluation, the baseline digested sludge disposition method is assumed to be landfill disposal. However, since the digested solids will meet Class B other disposal options are available including land application or composting. Details of the on-site anaerobic digestion alternative at each WWTF are summarized in the following sub-sections. 6.1.1 Grand Glaize WWTF Conceptual design solids flows and loads for the anaerobic digestion at Grand Glaize alternative are derived from the projected future solids production presented in Section 2 and summarized in Table 6.1. Table 6.1 Solids Flows and Loads – Anaerobic Digestion at Grand Glaize Annual Average Max Month WAS to Thickening 6,300 lb TSS/day 0.6 % TSS 125,900 gal/day 8,700 lb TSS/day 0.6% TSS 173,900 gpd Total Thickened Solids to Digestion (Thickened PS at 5% plus thickened WAS at 5%) 19,000 lb TSS/day 15,200 lb VSS/day 5% TSS 45,600 gal/day 26,000 lb TSS/day 20,800 lb VSS/day 5% TSS 62,400 gal/day Digested Solids to Dewatering 11,400 lb TSS/day 45,600 gal/day 15,600 lb TSS/day 62,400 gal/day Dewatered Solids to Landfill Disposal 5.13 dry tons/day 20% TS 25.65 wet tons/day 7.02 dry tons/day 20% TS 35.10 wet tons/day Metropolitan St. Louis Sewer District 60 Grand Glaize Sludge Odor (12725) 01/26/18 WAS thickening facilities include two RDTs, one operating and one standby, each sized for a WAS feed rate of 200 gpm. RDTs and ancillary equipment are housed in a new 1,500 square foot building. Anaerobic digestion facilities include three digesters, each with an operating volume of approximately 489,000 gallons. Two hot water boilers, one operating and one standby, are provided. Digester equipment is housed in a two story building with a total floor area of 5,000 square feet. WAS thickening and digestion process parameters and equipment are summarized in Table 6.2. Table 6.2 Thickening and Digestion Process Parameters – Grand Glaize WAS to Thickening RDT trains RDT capacity WAS flow per RDT (Annual Avg – Max Month) Thickened WAS concentration Polymer dose (active polymer) 1 operating + 1 standby 200 gpm ea. 87 – 121 gpm 5% 5 lb/dry ton Anaerobic Digesters Number of digesters Diameter Operating Depth Total sidewall height Operating Volume, ea. HRT, all units in service (Annual Avg - Max Month) HRT, one unit out of service (Annual Avg - Max Month) Volatile solids loading, all units in (Ann Avg - Max Month) Volatile solids loading, one unit out (Ann Avg - Max Month) Volatile solids destruction 3 55 feet 27.5 feet 31.5 feet 488,700 gal 32.2 days/23.5 days 21.4 days/15.7 days 0.08/0.11 lb VS/1000 ft3-d 0.12/0.16 lb VS/1000 ft3-d 50% Digester Gas Production Gas production, per lb VS destroyed Total gas production BTU content Total BTUs/day Potential CHP power production 16 cf/lb VS destroyed 121,600 cf/day 600 BTU/cf 72.96 MMBTU/day 340 kW A preliminary site plan showing new WAS thickening and anaerobic digestion facilities at Grand Glaize is shown on Figure 6.1. Metropolitan St. Louis Sewer District 61 Grand Glaize Sludge Odor (12725) 01/26/18 Figure 6.1 Preliminary Site Plan for Anaerobic Digestion at Grand Glaize Metropolitan St. Louis Sewer District 62 Grand Glaize Sludge Odor (12725) 01/26/18 Construction and total project costs for anaerobic digestion at Grand Glaize are summarized in Table 6.3. Table 6.3 Capital Costs – Anaerobic Digestion at Grand Glaize Cost Item Cost, 2017 $ WAS Thickening $ 1,449,000 Anaerobic Digestion $ 6,520,000 Electrical and Instrumentation $ 1,594,000 Site Work $ 956,000 Subtotal Direct Costs $10,519,000 General Conditions (12%)$ 1,262,000 Undefined Scope of Work/Contingency (35%)$ 3,682,000 Subtotal Construction Cost $15,463,000 Contractor Overhead and Profit (20%)$ 3,093,000 Total Construction Cost $18,556,000 Engineering, Administrative and Legal (20%)$ 3,711,000 Total Project Cost $22,267,000 Annual operations and maintenance costs for anaerobic digestion at Grand Glaize followed by landfill disposal of digested and dewatered solids are summarized in Table 6.4. Table 6.4 Annual O&M Costs – Anaerobic Digestion at Grand Glaize Cost Item Cost, 2017 $ Power $ 52,000 Chemicals (thickening polymer)$ 14,400 Equipment Maintenance $ 55,200 Hauling and Landfill Disposal $ 389,500 Total Annual Operations and Maintenance Costs $ 511,100 6.1.2 Lower Meramec WWTF Conceptual design solids flows and loads for the anaerobic digestion at Lower Meramec alternative are derived from the projected future solids production presented in Section 2 and summarized in Table 6.5. Metropolitan St. Louis Sewer District 63 Grand Glaize Sludge Odor (12725) 01/26/18 Table 6.5 Solids Flows and Loads – Anaerobic Digestion at Lower Meramec Annual Average Max Month WAS to Thickening 15,200 lb TSS/day 0.8 % TSS 227,800 gal/day 21,300 lb TSS/day 0.8% TSS 319,200 gpd Total Thickened Solids to Digestion (Thickened PS at 5% plus thickened WAS at 5%) 34,300 lb TSS/day 27,400 lb VSS/day 5% TSS 82,300 gal/day 26,000 lb TSS/day 20,800 lb VSS/day 5% TSS 115,100 gal/day Digested Solids to Dewatering 20,600 lb TSS/day 82,300 gal/day 28,800 lb TSS/day 115,100 gal/day Dewatered Solids to Landfill Disposal 9.27 dry tons/day 20% TS 46.35 wet tons/day 12.96 dry tons/day 20% TS 64.80 wet tons/day WAS thickening facilities include two RDTs, one operating and one standby, each sized for a WAS feed rate of 400 gpm. RDTs and ancillary equipment are housed in a new 1,500 square foot building. Anaerobic digestion facilities include three digesters, each with an operating volume of approximately 883,000 gallons. Two hot water boilers, one operating and one standby, are provided. Digester equipment is housed in a two story building with a total floor area of 7,200 square feet. WAS thickening and digestion process parameters and equipment are summarized in Table 6.6. Metropolitan St. Louis Sewer District 64 Grand Glaize Sludge Odor (12725) 01/26/18 Table 6.6 Thickening and Digestion Process Parameters – Lower Meramec WAS to Thickening RDT trains RDT capacity WAS flow per RDT (Annual Avg to Max Month) Thickened WAS concentration Polymer dose (active polymer) 1 operating + 1 standby 400 gpm ea. 158 – 221 gpm 5% 5 lb/dry ton Anaerobic Digesters Number of digesters Inside Diameter Operating Depth Total sidewall height Operating Volume, ea. HRT, all units in service (Annual Avg - Max Month) HRT, one unit out of service (Annual Avg - Max Month) Volatile solids loading, all units in (Ann Avg - Max Month) Volatile solids loading, one unit out (Ann Avg - Max Month) Volatile solids destruction 3 67 feet 33.5 feet 37.8 feet 883,500 gal 32.2 – 23.0 days 21.5 – 15.4 days 0.08 - 0.11 lb VS/1000 ft 3-d 0.12 - 0.16 lb VS/1000 ft 3-d 50% Digester Gas Production Gas production, per lb VS destroyed Total gas production Energy content Total BTUs/day, millions Potential CHP power production 16 cf/lb VS destroyed 219,200 cf/day 600 BTU/cf 131.52 MMBTU/day 620 kW A preliminary site plan showing new WAS thickening and anaerobic digestion facilities at Lower Meramec is shown on Figure 6.2. Metropolitan St. Louis Sewer District 65 Grand Glaize Sludge Odor (12725) 01/26/18 Figure 6.2 Preliminary Site Plan for Anaerobic Digestion at Lower Meramec Construction and total project costs for anaerobic digestion at Lower Meramec are summarized in Table 6.7. Table 6.7 Capital Costs – Anaerobic Digestion at Lower Meramec Cost Item Cost, 2017 $ WAS Thickening $ 1,585,000 Anaerobic Digestion $ 8,643,000 Electrical and Instrumentation $ 2,045,000 Site Work $ 1,227,000 Subtotal Direct Costs $13,500,000 General Conditions (12%)$ 1,620,000 Undefined Scope of Work/Contingency (35%)$ 4,725,000 Subtotal Construction Cost $19,845,000 Contractor Overhead and Profit (20%)$ 3,969,000 Total Construction Cost $23,814,000 Engineering, Administrative and Legal (20%)$ 4,763,000 Total Project Cost $28,578,000 Annual operations and maintenance costs for anaerobic digestion at Lower Meramec followed by landfill disposal of digested and dewatered solids are summarized in Table 6.8. Metropolitan St. Louis Sewer District 66 Grand Glaize Sludge Odor (12725) 01/26/18 Table 6.8 Annual O&M Costs, Anaerobic Digestion at Lower Meramec Cost Item Cost, 2017 $ Power $ 79,100 Chemicals (thickening polymer)$ 34,700 Equipment Maintenance $ 64,300 Hauling and Landfill Disposal $ 822,700 Total Annual Operations and Maintenance Costs $1,000,800 6.1.3 On-Site Alternative Summary The on-site alternative for Grand Glaize and Lower Meramec do not exist separately, but need to be considered together against the other alternatives presented in Section 1. As such, the costs for the on-site alternative for Grand Glaize and Lower Meramec are presented and totaled in Table 6.9. Table 6.9 Total Cost of On-Site Alternative At Grand Glaize At Lower Meramec Total Total Project Costs $22,267,000 $28,578,000 $50,845,000 Annualized Project Cost1 $1,429,000 $1,834,000 $3,263,000 Annual O&M Cost $512,000 $1,001,000 $1,513,000 Total Annual Cost $1,941,000 $2,835,000 $4,776,000 Total Present Worth Cost1 $30,249,000 $44,183,000 $74,431,000 1 Based on 20 years and 2.5% Metropolitan St. Louis Sewer District 67 Grand Glaize Sludge Odor (12725) 01/26/18 6.2 Regionalization at Lower Meramec WWTF An alternative to separate anaerobic digestion at Grand Glaize and Lower Meramec involves conveyance of solids from Grand Glaize to Lower Meramec and combined digestion at Lower Meramec of solids from both WWTFs. The conceptual design and costing approach to the evaluation of on-site digestion at both WWTFs was applied to the evaluation of the regionalized digestion at Lower Meramec. For this alternative, it is assumed that Grand Glaize solids would be conveyed in a new force main to the planned Fenton drop shaft and conveyed along with the raw wastewater flow to Lower Meramec. Solids flows and loads for the regionalized digestion alternative were estimated by summing Grand Glaize and Lower Meramec flows and loads used in Section 6.1.1 and Section 6.1.2. Solids flows and loads for the regionalized digestion alternative are summarized in Table 6.10. Table 6.10 Solids Flows and Loads – Regionalized Anaerobic Digestion at Lower Meramec Annual Average Max Month WAS to Thickening 21,500 lb TSS/day 0.7 % TSS 353,700 gal/day 30,000 lb TSS/day 0.7% TSS 493,100 gpd Total Thickened Solids to Digestion (Thickened PS at 5% plus thickened WAS at 5%) 53,300 lb TSS/day 42,600 lb VSS/day 5% TSS 127,800 gal/day 74,000 lb TSS/day 59,200 lb VSS/day 5% TSS 177,500 gal/day Digested Solids to Dewatering 32,000 lb TSS/day 127,800 gal/day 44,400 lb TSS/day 177,500 gal/day Dewatered Solids to Landfill Disposal 14.40 dry tons/day 20% TS 72.00 wet tons/day 19.98 dry tons/day 20% TS 99.90 wet tons/day WAS thickening facilities include two RDTs, one operating and one standby, each sized for a WAS feed rate of 400 gpm. RDTs and ancillary equipment are housed in a new 1,500 square foot building. Anaerobic digestion facilities include four digesters, each with an operating volume of approximately 924,000 gallons. Three hot water boilers, two operating and one standby, are provided. Digester equipment is housed in a two story building with a total floor area of 7,200 square feet. WAS thickening and digestion process parameters and equipment are summarized in Table 6.11. Metropolitan St. Louis Sewer District 68 Grand Glaize Sludge Odor (12725) 01/26/18 Table 6.11 Thickening and Digestion Process Parameters – Regionalized at Lower Meramec WAS to Thickening RDT trains RDT capacity WAS flow per RDT (Annual Avg to Max Month) Thickened WAS concentration Polymer dose (active polymer) 1 operating + 1 standby 400 gpm ea. 246 - 342 gpm 5% 5 lb/dry ton Anaerobic Digesters Number of digesters Inside Diameter Operating Depth Total sidewall height Operating Volume, ea. HRT, all units in service (Annual Avg - Max Month) HRT, one unit out of service (Annual Avg - Max Month) Volatile solids loading, all units in (Ann Avg - Max Month) Volatile solids loading, one unit out (Ann Avg - Max Month) Volatile solids destruction 4 68 feet 34 feet 38 feet 923,600 gal 28.9 – 20.8 days 21.7 – 15.69days 0.08 - 0.12 lb VS/1000 ft 3-d 0.12 - 0.16 lb VS/1000 ft 3-d 50% Digester Gas Production Gas production, per lb VS destroyed Total gas production Energy content Total BTUs/day, millions Potential CHP power production 16 cf/lb VS destroyed 340,800 cf/day 600 BTU/cf 204.48 MMBTU/day 970 kW A preliminary site plan showing new WAS thickening and anaerobic digestion facilities at Lower Meramec is shown on Figure 6.3. Metropolitan St. Louis Sewer District 69 Grand Glaize Sludge Odor (12725) 01/26/18 Figure 6.3 Preliminary Site Plan for Regionalized Anaerobic Digestion at Lower Meramec Construction and total project costs for regionalized anaerobic digestion at Lower Meramec are summarized in Table 6.12. Project costs for the new pipeline facilities to convey solids from Grand Glaize to the Fenton drop shaft were estimated separately and provided by MSD. Table 6.12 Capital Costs – Regionalized Anaerobic Digestion at Lower Meramec Cost Item Cost, 2017 $ WAS Thickening $ 1,585,000 Anaerobic Digestion $10,658,000 Electrical and Instrumentation $ 2,448,000 Site Work $ 1,469,000 Subtotal Direct Costs $16,160,000 General Conditions (12%)$ 1,939,000 Undefined Scope of Work/Contingency (35%)$ 5,656,000 Subtotal Construction Cost $23,755,000 Contractor Overhead and Profit (20%)$ 4,751,000 Total Construction Cost $28,506,000 Engineering, Administrative and Legal (20%)$ 5,701,000 Subtotal Project Cost – Lower Meramec $34,207,000 Project Cost – Grand Glaize Solids Conveyance $13,000,000 Total Project Cost $47,207,000 Metropolitan St. Louis Sewer District 70 Grand Glaize Sludge Odor (12725) 01/26/18 Annual operations and maintenance costs for regionalized anaerobic digestion at Lower Meramec followed by landfill disposal of digested and dewatered solids are summarized in Table 6.13. Table 6.13 Annual O&M Costs, Regionalized Anaerobic Digestion at Lower Meramec Cost Item Cost, 2017 $ Power $ 102,600 Chemicals (thickening polymer)$ 49,000 Equipment Maintenance $ 84,400 Hauling and Landfill Disposal $1,278,000 Total Annual Operations and Maintenance Costs $1,514,000 6.2.1 Renewable Natural Gas The potential for generating revenue from the sale of “renewable identification numbers” or RINs by treating digester gas to pipeline quality, referred to as renewable natural gas (RNG), and injecting the treated gas into the regional natural gas grid was evaluated for the regionalized digestion facility at Lower Meramec alternative. The District would injecting RNG into Spire Energy’s distribution infrastructure. In doing so, the biogas generated by the District will need to meet or exceed all natural gas quality set by Spire Energy and included in Appendix D. Congress created the Renewable Fuels Standard (RFS) through the Energy Policy Act of 2005 and revised the program with the Energy Independence and Security Act in 2007. The RFS is a renewable fuels program within the Clean Air Act which mandates that large fuel producers and blenders (Obligated Parties) must include within their fuel mix a growing portion of renewable fuels. The quotas required of the Obligated Parties are referred to as Renewable Volume Obligations (RVOs) and are established and tracked by the EPA through the use of renewable credits, also known as, Renewable Identification Numbers (RINs). The original program was designed to increase the RVOs until 2022 and then level off beyond that point unless Congress issued another amendment. The EPA can lower or raise the RVOs up to the maximum RVO quota set for 2022 but Congressional action would be required to eliminate the RFS program. Pressure by the new administration to reduce or eliminate the need for RIN credits will likely be met with resistance from blue states as well as resistance from corn / ethanol producing red states who represent half of the RIN market. However, current thinking is that it is more likely that RINs will maintain or decline in value rather than increase in value. RINs generated using wastewater biomass are considered cellulosic fuel RINs which are targeted to grow the most and have the highest value. EPA issued the 2018 quota in June 2017 and reduced the amount of cellulosic RINS from 2017 volumes by 23%, siting a lack of adequate supply of these fuels. In addition, the EPA also announced it would be revaluating the RFS quotas going forward. The process is set to begin within the next few months. It is likely that cellulosic fuels will be limited in future growth give current federal focus on other energy supply sources. Metropolitan St. Louis Sewer District 71 Grand Glaize Sludge Odor (12725) 01/26/18 In addition to RINs, carbon offset credits are also available through California’s Low Carbon Fuel Standard (LCFS) program. The LCFS program was just reaffirmed by the California legislature within bills approved in July 2017. The LCFS market will continue to grow as carbon offset reduction goals are increased and unlikely to go away. LCFS credits can be obtained in addition to RIN credits as long as the renewable fuel is contracted for sale to an Obligated Party with end use in California. A final requirement to be aware of for both of these programs is that they are specifically renewable fuels for transportation programs. As such, the fuel must ultimately be used as a transportation fuel in order for the renewable attribute to be recognized. A renewable fuel producer is not required to explicitly find a transportation end user of the fuel it produces, however, at some point along the fuel supply pathway, it must be used as transportation fuel so that an Obligated Party can claim the RIN and/or the LCFS credit and meet its obligation with the EPA or with California. In order for the District to qualify as a renewable fuel producer, it would need to work with the local natural gas distribution company or a natural gas transmission company on injection location, pressure, quality and other specifications and then enter into a contract with a third party to sell the renewable natural gas and its associated renewable attributes. These third parties are either gas marketing companies or the Obligated Parties themselves, and are typically selected by an RFP process. The resulting contractual arrangement specifies the District’s share based on either a fixed price or percentage of total revenue and the term of the agreement. A typical share is 85 percent of revenue and a typical term is three to five years. The third party will qualify the RINs with EPA, qualify with California for LCFS credits, develop QA programs for certification, and administer the program. The District is paid by the third party for both the fuel value and the associated renewable attributes based on a monthly invoice. Lastly, because greenhouse gas (GHG) reduction is still a global environmental phenomena and because there is international support for GHG reduction, there is also an international demand for purchase of renewable attributes from RNG projects. Data on international renewable attribute markets are limited but information from renewable fuel suppliers indicates that values in the range of $10/MMBTU are feasible. The comparative cost presented in Table 6.14 presents values for the three RIN groups which are: ””D3 – Cellulosic (WWTF RNG) ”D5 – Advanced (Non-WWTF RNG and other renewable fuels besides ethanol and biodiesel) ”D6 – Renewable (Ethanol) RNG RINs can qualify for any of the categories and the intermediate RINs value was used to calculate the annual gross revenue. Metropolitan St. Louis Sewer District 72 Grand Glaize Sludge Odor (12725) 01/26/18 Table 6.14 RINS and Carbon Market Comparative Costs Current RINs and Carbon Market Intermediate RINs and Carbon Market Low End RINs and Carbon Market Commodity Price of RNG ($/MMBTU)$3 $3 $3 D3 RIN ($/MMBTU)$37 - - D5 RIN ($/MMBTU)-$13- D6 RIN ($/MMBTU)--$12 CA Low Carbon Fuel Standard at $100/metric ton based on CARB ($/MMBTU) $7 $7 $7 District share of green attributes 85% 85% 85% Total ($/MMBTU)$40 $18.70 $12.75 Additional facilities for the regionalized digestion at Lower Meramec alternative to produce and deliver RNG include a digester gas treatment system and RNG conveyance and pipeline injection facilities. Based on the average biogas production rate of 200 MMBTU/day, a 300 scfm biogas treatment system is proposed to accommodate current operations with some expansion capacity. To achieve the required gas quality criteria and parameters set by Spire Energy, a 2- pass membrane biogas treatment system is proposed. The membrane biogas treatment system generally consist of the following equipment and processes: ””Hydrogen sulfide removal system (may be necessary due to biogas quality – to be determined during detailed design). ”Moisture, siloxane, and carbon dioxide removal systems consisting of a gas compression and cooling heat exchanger system, media, and membrane technology. Figure 6.4 shows a simple process diagram of the proposed biogas treatment system. Metropolitan St. Louis Sewer District 73 Grand Glaize Sludge Odor (12725) 01/26/18 Figure 6.4 Biogas Treatment System Process Design The biogas treatment system is proposed to be installed outdoors on a common concrete equipment pad located south of the proposed digestion facility. This area will also accommodate installation of the new flare system that will serve as back-up to discharging RNG into the natural gas pipeline grid. RNG discharged to the flare will have its pressure reduced to 5-10 psi. RNG discharged to the pipeline injection point will have its pressure reduced to approximately 35 psi and discharged to a new Gas Analyzer Building installed close to the WWTF entrance. This building will house all necessary instrumentation to demonstrate compliance with the RNG specifications to meet pipeline injection quality criteria which includes RNG flow measurement, gas quality monitoring, pressure regulation, and odorization, with telemetry capability and the ability to shut-in the station (stop flow, flare non-specification gas and nitrogen purge the interconnection piping) if gas quality specifications are not being met. The cost of the Gas Analyzer Building could possibly be rolled into a facilities interconnection agreement over a set period of time or through direct capital costs. Transportation costs could be covered in monthly or annual payments and typically would entail moving gas on to the grid and any ongoing maintenance. Agreements to the cost structure would need to be negotiated by the District. The alternative of adding RNG to the regionalized approach at Lower Meramec would increase total project capital costs from $47.2 million to approximately $55.4 million. Annual operations and maintenance costs would also increase for the added digester gas treatment and RNG regulator station equipment. Because the RNG $/MMBTU RIN value is higher than the natural gas $/MMBTU cost, it is also assumed that 100% of the digester gas would be treated and injected into the natural gas grid as RNG with digester heating demands would be supplied by purchased natural gas. Total annual operations and maintenance costs would increase to an estimated $1,900,000 under the regionalized digestion option at Meramec, of which approximately $400,000 would be directly related to the RNG system. However, revenue from the sale of RINs would significantly offset annual operations and maintenance costs. Potential revenue from RIN sales was estimated assuming 100% of the Lower Meramec RNG is delivered to the grid and sold as Metropolitan St. Louis Sewer District 74 Grand Glaize Sludge Odor (12725) 01/26/18 vehicle fuel with net RIN revenue to MSD of $20/MMBTU. Total revenue to MSD based on those assumptions would be approximately $1,493,000 annually. 6.2.2 Regionalization at Lower Meramec Summary The costs associated with regionalization at Lower Meramec along with the sub-alternative for adding RNG are presented and totaled in Table 6.15. Table 6.15 Total Cost of Regionalization at Lower Meramec Regionalized at Lower Meramec Regionalized at Lower Meramec with RNG Project Costs – WWTFs $34,207,000 $42,437,000 Project Costs – Solids Conveyance $13,000,000 $13,000,000 Total Project Costs $47,207,000 $55,437,000 Annualized Project Cost1 $3,029,000 $3,557,000 Annual O&M Cost $1,515,000 $1,900,000 Annual Revenue, RNG RINs $0 ($1,493,000) Total Annual Cost $4,544,000 $3,964,000 Total Present Worth Cost1 $70,825,000 $61,782,000 1 Based on 20 years and 2.5% 6.3 Regionalization at Missouri River WWTF A regional sludge processing facility at Missouri River WWTF would process sludge from Missouri River WWTF, Grand Glaize WWTF, and Lower Meramec WWTF. Sludge can either be pumped or hauled to Missouri River WWTF. Because of the distance between both Lower Meramec and Grand Glaize to Missouri River WWTF, this alternative only analyzes hauling sludge cake. Due to MSD’s desire to eliminate hauling of raw sludge completely in the future, this option was only preliminarily analyzed for comparative purposes and is not included in the evaluation of other alternatives in Section 6.4. Given that this approach requires hauling raw sludge, the receiving sludge handling process must accommodate the hauled sludge cake which results in implementing a Thermal Hydrolysis Process (THP; digestion pre-treatment process) at Missouri River WWTF. Table 6.16 summarizes the sludge characteristics and cost for transportation between the generating WWTF and Missouri River WWTF. Metropolitan St. Louis Sewer District 75 Grand Glaize Sludge Odor (12725) 01/26/18 Table 6.16 Average Annual Sludge Hauling Costs for Regional Facility at MO River WWTF Facility Total Hauling Cost1 Future Annual Average Total Wet Solids Annual Average Cake Annual Average Dewatered Sludge Hauling Cost Total Annual Average Dewatered Sludge Hauling Cost $/Wet Ton wtpd %TS $/year $/year Grand Glaize $14.96 31.5 26% $172,000 $597,600Lower Meramec $22.00 53.0 29% $425,600 1 Hauling Costs based on 17 mile haul distance and associated wet ton unit price of $14.93/ton hauling for Grand Glaize WWTF and 25 mile haul distance and associated wet ton unit price of $22.00/ton hauling for Lower Meramec WWTF. The transported sludge cake from the generating WWTFs will be collected and combined with the Missouri River WWTF sludge in a sludge feedstock hopper. This hopper should be sized to accommodate a 3-day weekend resulting in over 18,000 ft3 of sludge storage. To achieve the desired 16.5 %TS THP sludge feed concentration, the sludge will be re-wetted twice, once upon arrival when discharging into the hopper to reduce the sludge solids concentration to approximately 20-22% and then again when discharging sludge to the THP process at the desired 16.5% TS. THP requires a one week maintenance shutdown which would require each wastewater treatment facility to store sludge within its process tanks and haul sludge cake to the landfill as necessary. Along with the new feedstock hopper and THP system, Missouri River WWTF would also require two pre-dewatering belt filter presses (or centrifuges) to generate the dewatered sludge that would discharge into the feedstock hopper, positive displacement sludge cake THP feed pumps and a 5 mm sludge screening process to remove unwanted inorganic solids prior to entering the THP. The existing process piping currently discharging to the centrifuges would need to be modified to receive and dewater Class A biosolids discharged from the THP. The Class A product could benefically used or disposed in a landfill. Landfill disposal was assumed for the purposes of this evaluation. A single THP process train would be provided, comprising a modular THP process reactor skid with a maximum throughput of 92 dry tons/day, cooling heating exchangers, and THP process feed pumps. THP solids are diluted to 10% TS and cooled before they are introduced to the anaerobic digesters. Existing firm digester capacity at Missouri River WWTF is more than enough to accommodate the 10% TS solids feed from the THP process, so no additional digester capacity is required. The THP process significantly reduces the viscosity of the THP solids so existing digester recirculation and mixing equipment can continued to be used. Metropolitan St. Louis Sewer District 76 Grand Glaize Sludge Odor (12725) 01/26/18 A side-stream centrate treatment process will be required to reduce the ammonia recycle load generated as a byproduct of THP. Side-stream treatment is typically a “short-cut” or deammonification nitrogen removal process, which reduces the aeration power demand for removing the high ammonia loads in the centrate. THP also increases sludge bio-degradability and therefore increases biogas production. A volatile solids destruction of 60% is typical for the THP anaerobic digestion process. Based on preliminary analysis, the estimated theoretical biogas production for a regionalized THP process at Missouri River is approximately 530 cfm at future design loads. Improved dewatering performance is also typical for THP anaerobic digestion process solids. A dewatered solids concentration of 30% is expected. Based on typical THP volatile solids destruction and dewatering performance, projected annual average dewatered solids production for the regionalized THP alternative is 23.6 dry tons/day and 78.8 wet tons/day. Plant operators note that existing sludge cake pumping equipment is limited to a maximum cake of 25% due to limitations in pumping of sludge cake to the silo. Thus, these pumps would need to be replaced as part of this alternative. A high-level concept cost for a regionalized THP facility at Missouri River was estimated using costs from recent HDR evaluations for THP retrofits of similar size at other WWTFs. Annual operations and maintenance costs were estimated using the same approach and cost parameters as for the on-site and regionalized anaerobic digestion alternatives. Digester gas treatment to RNG quality and potential revenue from the sale of RINs were included in the cost evaluation. Overall costs were then allocated to Grand Glaize and Lower Meramec in proportion of the combined solids from those facilities to the total (including Missouri River solids), to allow direct comparison to the on-site and regional anaerobic digestion alternatives. High-level conceptual costs for the regionalized THP alternative are summarized in Table 6.17. Table 6.17 Estimated Cost for Regional THP Facility at MO River WWTF Regional THP at Missouri River Allocated to Grand Glaize and Lower Meramec Project Costs $60,338,000 $28,359,000 Annualized Project Cost1 $3,871,000 $1,820,000 Annual O&M Cost $3,163,000 $1,804,000 Annual Revenue, RNG RINs ($3,402,000) ($1,599,000) Total Annual Cost $3,632,000 $2,025,000 Total Present Worth Cost1 $56,612,000 $31,555,000 1 Based on 20 years and 2.5% Metropolitan St. Louis Sewer District 77 Grand Glaize Sludge Odor (12725) 01/26/18 As mentioned at the beginning of this section, due to MSD’s desire to eliminate hauling of raw sludge completely in the future, this option was only preliminarily analyzed for comparative purposes and is not included in the evaluation of other alternatives in Section 6.4. However, if the costs reported in Table 6.19 are compared to other costs presented in this section, it is important to note that this option results in the production of Class A biosolids from all three facilities (Grand Glaize, Lower Meramec – including Fenton flows, and Missouri River). While the other options presented only result in Class A biosolids from two facilities (Grand Glaize and Lower Meramec – including Fenton flows). Therefore, the numbers are not necessarily directly comparable. 6.4 Evaluation of Long-Term Alternatives Costs for the anaerobic digestion alternatives are compared in 2017 dollars in Table 6.18. Annual costs were calculated as the sum of annual operations and maintenance costs and an annualized project cost based on a 20-year term and an interest rate of 2.5%. Table 6.18 Cost Comparison of Anaerobic Digestion Alternatives On-Site At Grand Glaize and Lower Meramec Regionalized at Lower Meramec Regionalized at Lower Meramec with RNG Project Costs – WWTFs $50,845,000 $34,207,000 $42,437,000 Project Costs – Solids Conveyance1 $0 $13,000,000 $13,000,000 Total Project Costs $50,845,000 $47,207,000 $55,437,000 Annualized Project Cost2 $3,263,000 $3,029,000 $3,557,000 Annual O&M Cost $1,513,000 $1,515,000 $1,900,000 Annual Revenue, RNG RINs $0 ($1,493,000) Total Annual Cost $4,776,000 $4,544,000 $3,964,000 Total Present Worth Cost2 $74,431,000 $70,825,000 $61,782,000 1 Cost of solids conveyance from Grand Glaize to Lower Meramec was provided by the District and does not include additional cost for odor control along the length of the tunnel that would likely be required. 2 Based on 20 years and 2.5% Digestion alternatives can be compared on relative costs and operational considerations. On a cost basis, there is a potential economy of scale for regionalized digestion at Lower Meramec, which has a slightly lower annual cost of $4.5 million compared to the combined cost of $4.8 million for on-site digestion at both Grand Glaize and Lower Meramec. However, that small difference in annual cost may not be significant at the level of detail offered by this planning- Metropolitan St. Louis Sewer District 78 Grand Glaize Sludge Odor (12725) 01/26/18 level conceptual evaluation. The relative cost advantage of the regionalized digestion alternative is more pronounced if the RIN potential of treated digester gas is realized. From an operational standpoint, the regionalized alternative consolidates digestion, dewatering and hauling at a single facility rather than at two facilities as under the on-site digestion alternative, reducing operations and maintenance demands on MSD staff. Potential implications for nutrient removal process improvements and performance and other operational impacts of conveying Grand Glaize solids to Lower Meramec should also be considered in comparing anaerobic digestion alternatives. If Grand Glaize solids are conveyed to Lower Meramec via the Fenton drop shaft (the more cost effective alternative), the majority of the Grand Glaize solids (80 to 90 percent based on experiences at other WWTFs with similar solids transfers) would be expected to settle with the primary solids at Lower Meramec. So impacts of additional organic and nitrogen loadings to the BNR process are relatively minor. If a Bio-P process is selected for Grand Glaize, P removal requirements would increase at Lower Meramec to remove P release from the Grand Glaize WAS during transit in the conveyance system. WAS from Grand Glaize would consume some of the readily biodegradable COD in the raw wastewater flow during transit, reducing the efficiency of BNR at Lower Meramec. Nitrate in the Grand Glaize WAS will also denitrify and release nitrogen gas in the conveyance system, which may increase the number of gas relief valves and associated maintenance in force main sections of the Grand Glaize solids conveyance. Anaerobic digestion alternatives can also be compared to the long-term alternative of hauling solids from Grand Glaize and Lower Meramec (including Fenton) to Bissell Point for incineration. Annual costs for incineration, presented in Table 4.4, are updated to future solids productions used for the long-term alternatives and compared to those for the anaerobic digestion alternatives in Table 6.19. As shown, incineration is significantly more cost effective than anaerobic digestion and landfill disposal. However, anaerobic digestion does eliminate hauling of raw solids and may support beneficial use of biosolids as an alternative to disposal. It is important to note that the cost for incineration at Bissell Point presented does not include the cost of any capital improvements that may be required to continue operation over the next 20 years. Table 6.19 Comparison of Anaerobic Digestion Alternatives to Incineration Alternative Annual Cost On-Site Digestion at Grand Glaize and Lower Meramec $4,776,000 Regionalized Digestion at Lower Meramec $4,544,000 Regionalized Digester at Lower Meramec with RNG-RINs $3,964,000 Incineration at Bissell Point1 $1,468,000 1 Cost does not include future capital improvements to incineration at Bissell Point WWTF. Metropolitan St. Louis Sewer District 79 Grand Glaize Sludge Odor (12725) 01/26/18 Appendix H – Air Emissions Analysis Memorandum To: File From: Cindy Cullen Date: 4/25/2018 Re: Air Permitting Evaluation for Future Solids Handling Planning The Solids Planning Team requested this evaluation to support the assessment of air permit requirements for potential sewage sludge projects at MSD treatment plants. These projects are detailed in Table 1. This memorandum serves to summarize findings and document the methodology applied to the permitting evaluation. Table 1: Sewage Sludge Projects for Air Permitting Evaluation Sewage Sludge Project Description Master Regional  FBIs installed at Bissell Point to treat sludge from Bissell Point, Coldwater, Lemay, Grand Glaize, Fenton, and Lower Meramec  Missouri River will remain as-is Sub-Regional, Lower Meramec Digesters Only  FBIs installed at Bissell Point to treat sludge from Bissell Point, Lemay, and Coldwater  Anaerobic digesters and associated digester gas combustion equipment installed at Lower Meramec to treat sludge from Lower Meramec, Grand Glaize, and Fenton  Missouri River will remain as-is Sub-Regional, Lower Meramec and Grand Glaize Digesters  FBIs installed at Bissell Point to treat sludge from Bissell Point, Lemay, and Coldwater  Anaerobic digesters and associated digester gas combustion equipment installed at Lower Meramec to treat sludge from Lower Meramec and Fenton  Anaerobic digesters and associated digester gas combustion equipment installed at Grand Glaize to only treat sludge from Grand Glaize  Missouri River will remain as-is City-County Incineration  FBIs installed at Bissell Point to treat sludge from Bissell Point and Coldwater  FBIs installed at Lemay to treat sludge from Lemay, Grand Glaize, Fenton, and Lower Meramec  Missouri River will remain as-is New Source Review for Sludge Handling Options Because MSD may install new equipment that produces air emissions, MSD must evaluate whether these changes trigger New Source Review (NSR) per the Clean Air Act. NSR applies to the National Ambient Air Quality Standards (NAAQS) pollutants and a few other pollutants. There are three sets of NSR permitting programs, including: (1) Prevention of Significant Deterioration (PSD), (2) Nonattainment New Source Review (NNSR), and (3) Minor NSR. The applicability of these programs to a project depends on: 2    1. The amount of project emissions; and 2. The NAAQS attainment designation for the project location, which depends on ambient air quality and is determined by the State and the U.S. Environmental Protection Agency (EPA).1 PSD and NNSR permits can be difficult to maneuver and may not be feasible due to extensive permitting requirements, so it is important to understand the potential permitting pathway for a project as early as possible. The first step in assessing NSR applicability is to calculate the maximum amount of NSR pollutants that a project could emit. This is known as the potential to emit (PTE). The PTE is calculated using the maximum throughput capacity of equipment and emission factors for the equipment. The maximum throughput capacity can be determined based on design information, operational limitations, and sometimes permit requirements. Emission factors can be determined from test data, material-balance calculations, source-specific models, EPA or other approved agency emission factors, federally-enforceable permit or regulatory requirements, or other site-specific emission factors that are approved by the State or the EPA.2 The next step for NSR is to compare the PTE for each pollutant to the de minimis levels3 which are shown in Table 2. If all pollutants are below the de minimis levels, then the project falls under Minor NSR. If all or some pollutants are above the de minimis values, the permitting determination depends on the existing conditions at the facility. For instance, if the existing facility is considered de minimis, the project would fall under the PSD and/or NNSR programs, unless the facility took voluntary permit limits to prevent the PTE from exceeding the de minimis levels. If the existing facility is already above the de minimis levels, the project would fall under the PSD and/or NNSR programs unless a netting analysis is conducted to demonstrate that the project will not significantly contribute to an increase in emissions at the facility. 4 Table 2: De Minimis Levels Pollutant De Minimis Level (tpy)a Carbon monoxide (CO) 100.0 Nitrogen oxides (NOx) 40.0 Sulfur dioxide (SO2) 40.0 Particulate matter (PM) 25.0 PM10 15.0 PM2.5 10.0 VOCs 40.0 Lead (Pb) 0.6 Fluorides 3.0 Sulfuric acid mist 7.0 Hydrogen sulfide 10.0 Total reduced sulfur compounds (including H2S) 10.0 Reduced sulfur compounds (including H2S) 10.0 a Source: 10 CSR 10-6.020(3)(A)                                                              1 U.S. Environmental Protection Agency. FACT SHEET: New Source Review (NSR).  <https://www.epa.gov/sites/production/files/2015‐12/documents/nsrbasicsfactsheet103106.pdf>.  2 U.S. Environmental Protection Agency. Potential to Emit, A Guide for Small Businesses. Oct 1998.  <https://www3.epa.gov/airtoxics/1998sbapptebroc.pdf>.  3 De minimis level can also be referred to as the significant emission rate (SER).  4 Missouri Department of Natural Resources. Air Construction Permits Guidance.  <https://dnr.mo.gov/env/apcp/permits/constpmtguide.htm>.  3    In general, a netting analysis involves the calculation of the project PTE minus baseline emissions and any creditable emissions. The Michigan Department of Environmental Quality fact sheet titled, “Guidelines for a Netting Demonstration,”5 provides more detailed instructions on conducting a netting analysis. Baseline emissions for the treatment plants are the average rate of emissions that actually occurred over any consecutive 24-month period within the 10-year period preceding the date that the complete construction permit application is submitted.6 The selected 24-month period should be representative of equipment operations. A different baseline period can be selected for each pollutant. The net change in emissions for each pollutant is compared to the associated de minimis level. If the net change is less than the de minimis level, then the Minor NSR Program applies. If the net change is greater than the de minimis level, then the PSD and/or NNSR programs apply. However, a facility can take a permitted throughput limit to “net out” of PSD or NNSR requirements and only be subject to the Minor NSR program. Greenhouse Gases Greenhouse gases (GHGs) also need to be considered in an air permitting evaluation. The U.S. Supreme Court ruled that the U.S. EPA cannot treat greenhouse gases (GHGs) as an air pollutant solely for a PSD determination.7 However, if a source is subject to PSD for other pollutants, then the source can be regulated for GHGs. Thus, the project PTE and netting calculations, if applicable, are also conducted for GHGs. The de minimis level for GHGs is 75,000 tons per year (tpy) carbon dioxide equivalent emissions (CO2e).8 Air Toxics The PTE for Hazardous Air Pollutants (HAPs) must also be considered for air permitting. When a Maximum Achievable Control Technology (MACT) standard applies to a project, the project is considered to be a major source if the total HAPs are greater than 25 tpy or if an individual HAP is greater than 10 tpy. If a project is major for HAPs, then a major source permit is required. A netting analysis can be used for these calculations, if applicable to the project. Additionally, Missouri has a second set of HAPs requirements, which includes a list of HAPs in Appendix J of 10 CSR 10-6.6060 with action levels. If the project PTE for an individual HAP exceeds the Screening Model Action Level (SMAL), then modeling is required. If the modeled impact exceeds the Risk Assessment Level (RAL), then the project must make modifications (e.g., permit limits or design changes) to resolve the air quality issue.9 Bissell Point and Lemay MHI Permitting Evaluation The permitting calculations for Bissell Point and Lemay can be found here. For the PTE calculations, the new FBIs should not be tied to the existing permitted sludge throughputs at the plants because these limits are for the MHIs. Typically, the FBI maximum design throughput would be used for PTE calculations; however, this information is not available. For a starting point, the existing sludge throughputs limits for each plant were used: 74,369 tpy at Bissell Point and 7.41 tons per hour (or 64,912 tpy) at Lemay. Historic maximum sludge production data for each incineration scenario was compiled, as shown in Table 3, for comparison to the existing permitted throughput limits. The historic sludge data indicates that a                                                              5 Michigan Department of Environmental Quality – Air Quality Division. Guidelines for a Netting Demonstration.  Oct 2004. < http://www.michigan.gov/documents/deq/DEQ‐AQD‐PTI‐Netting_Demo_356087_7.pdf>.  6 40 CFR §52.21(b)(48)  7 U.S. Environmental Protection Agency. New Source Review Permitting, Clean Air Act Permitting for Greenhouse  Gases. <https://www.epa.gov/nsr/clean‐air‐act‐permitting‐greenhouse‐gases>.  8 40 CFR §52.21(b)(49)(iv)  9 Missouri Department of Natural Resources. Missouri Risk Assessment Levels. Nov 2013.  <https://dnr.mo.gov/env/apcp/docs/riskassesslevels.pdf>.  4    throughput limit increase would likely be needed if a regional incineration facility is implemented at Bissell Point or if more buffer room is needed for the Sub-Regional option. Thus, the calculation spreadsheets were set up to calculate the maximum throughput possible without triggering the need for a major source permit or HAPs modeling. Table 3: Historic Annual Dry Sludge Production Option Description 10-Year Annual Max. Sludge Produced (dry tons) Master Regional FBIs at Bissell Point to treat sludge from Bissell Point, Coldwater, Lemay, Grand Glaize, Fenton, and Lower Meramec 75,322 Sub-Regional FBIs at Bissell Point to treat sludge from Bissell Point, Lemay, and Coldwater 68,239 City-County Incineration FBIs at Bissell Point to treat sludge from Bissell Point and Coldwater. 47,525 FBIs at Lemay to treat sludge from Lemay, Lower Meramec, and Fenton. 27,797 Emission factors were obtained for some of the NSR pollutants (i.e., particulate matter, carbon monoxide, nitrogen dioxide, sulfur dioxide, and lead) from 40 CFR part 60, Subpart LLLL, which establishes performance requirements for MHIs. The rationale for these emission factors was that the MHI design will be required to meet these emission limits at a minimum. The emission factors for volatile organic compounds (VOCs), methane (a GHG constituent), and sulfuric acid were obtained from the U.S. EPA’s AP-42.10 The GHG constituents, CO2 and N2O, were obtained from IPCC11 and 40 CFR Part 98, respectively. Calculations Using the Existing Throughput Limit For the Lemay and Bissell Point PTE calculations with the existing sludge throughput limits, the de minimis levels for GHGs, total HAPs, and dichlorobenzene are exceeded. The SMAL is also exceeded for dichlorobenzene. Thus, a netting analysis was conducted using the hybrid test per 40 CFR §52.21(a)(2)(iv)(f). Basically, for this test, the decrease in emissions from decommissioning the MHIs was subtracted from the increase in emissions from the new FBIs. It was assumed that there would be a net decrease because FBIs are more efficient combustion units and have more stringent emission limits. For the netting analysis, the baseline emissions for the MHIs were established. It should be noted that although the MHIs at Lemay and Bissell Point operate below their existing sludge throughput limits, MSD cannot take credit for these unused emissions in the netting analysis. At the time of the calculations, the planning team said that construction would start in the late summer of 2024, so August 2024 was selected to start the lookback period. The baseline emissions were calculated using historic throughput data and emission factors from Emission Inventory Questionnaires (EIQs), engineering calculations, AP-42, IPCC, and 40 CFR Part 98. The lookback period included actual emissions from 2014, 2015, and 2016. The 2016 emissions were projected out through August 2024. Because a large portion of the                                                              10 U.S. Environmental Protection Agency. AP‐42: Compilation of Air Emission Factors. < https://www.epa.gov/air‐ emissions‐factors‐and‐quantification/ap‐42‐compilation‐air‐emission‐factors>.  11 Intergovernmental Panel on Climate Change. 2006 IPCC Guidelines for National Greenhouse Gas Inventories.  <http://www.ipcc‐nggip.iges.or.jp/public/2006gl/vol5.html>.  5    lookback period data is missing (2017-2024), the minimum 24-month rolling average was used as the worst case baseline for each pollutant. For the final netting analysis:  The lookback period will change if the construction date changes;  The selected 24-month period for the average baseline emissions will need to be updated to reflect representative emissions;  The average emissions from the 24-month selected period will be used (not the minimum); and  Actual emissions from 2017 forward will need to be input to the analysis. The netting analysis for Bissell Point indicated that the project would still exceed the de minimis levels for total HAPs and dichlorobenzene. Both exceedances are due a high dichlorobenzene emission factor from AP-42; however, project design engineers should be able to develop a lower emission factor for dichlorobenzene so that the de minimis level is not exceeded. The netting analysis for Lemay indicated that the project would exceed the de minimis levels for GHGs and dichlorobenzene and the SMAL for dichlorobenzene. If design engineers resolve the dichlorobenzene emission factor issue, then GHGs will not be an issue because GHGs cannot be the sole pollutant used to make a PSD determination. Thus, both Bissell Point and Lemay should be able to obtain Minor NSR permits for FBIs with the existing sludge throughput limits. Maximizing the Throughput To find the maximum throughput for the FBIs, trial and error was used to input different sludge throughputs to the calculations. For both Bissell Point and Lemay, it was determined that the maximum throughput for the FBIs could be around 110,000 dry tpy, depending on final design data. Thus, all incineration scenarios included in Table 1 are possible. At the maximized throughput, the netting analyses for both plants showed that the de minimis levels were exceeded for GHGs, total HAPs, dichlorobenzene, and naphthalene. The SMALs were exceeded for dichlorobenzene and naphthalene. Design engineers should be able to develop lower emission factors for the individual HAPs, so that the HAPs de minimis levels and the SMALs are not an issue. These design emission factors would resolve the total HAPs issue, and the remaining GHG exceedance would not trigger PSD permitting. Therefore, it is possible to increase the throughput limit at both plants and still obtain a Minor NSR permit. It is also possible that the throughput limit could be higher than 110,000 dry tpy if the design engineers develop lower emission factors than the factors used for this evaluation. Additionally, although final design and regulatory input is uncertain, there is some potential that the FBIs will not need a permit limit if the FBI maximum throughput inherently limits the PTE. Further evaluation is needed as the project progresses and as MSD begins to communicate project details with MDNR to make a more conclusive throughput limit determination. Ash Handling Both Bissell Point and Lemay currently use a wet ash handling system for combustion ash from the MHIs and have a dry ash system that is not being used. MSD discussed using a dry ash system with the FBIs to promote beneficial reuse of the combustion ash. However, the scope of this project is not defined at this time. For preliminary calculations, it was assumed that a new dry ash system would be installed. The project PTE and netting analysis were calculated assuming the shutdown of the wet ash systems. For a conservative calculation, the maximum ash throughput capacity was based on the sludge throughput with a zero percent (0%) volatiles content. Final calculations should consider actual volatiles content or perhaps use the design ash system throughput if there is no sludge throughput limit and/or if the ash system causes a bottleneck. The WebFIRE emission factors that were used for this evaluation were also used to permit the existing dry ash systems. 6    The netting analysis indicated that the de minimis levels for total HAPs and lead were exceeded, with lead being the culprit for the total HAPs exceedance. MSD should consider developing a lead emission factor from site-specific ash analysis information rather than using a WebFIRE emission factor, with the consideration of the loss in mass between the dry sludge and incinerator ash. Another option would be to route ash handling emissions to the FBI air pollution control equipment, if feasible. This is because the FBIs have a low lead emission limit under 40 CFR part 60, Subpart LLLL, which would be used as the maximum lead emission factor for both the FBIs and the ash handling system. For the final construction permitting process, the lead emission factor will need to be addressed to ensure that Bissell Point and Lemay can obtain Minor NSR permits. Additionally, further evaluation is needed if the plants decide on a different ash handling scenario. Anaerobic Digester & Combustion Equipment Permitting Evaluation The permitting calculations for the digester gas combustion scenarios at Lower Meramec and Grand Glaize can be found here. For these calculations, it was assumed that Lower Meramec and Grand Glaize would have the same digester gas combustion equipment that is used at Missouri River treatment plant. This equipment includes two (2) boilers, three (3) internal combustion engines, and one (1) waste gas flare. The digester gas production was estimated for the new digesters based on historic sludge and digester gas production data and found that the Missouri River equipment would provide sufficient combustion capacity. For the PTE calculation, the maximum throughput of the combustion units was used. Vendor data was used from Missouri River’s equipment for most of the engine emission factors. To develop sulfur dioxide emission factors for all of the equipment, historic data was used from Missouri River for the digester gas hydrogen sulfide content. Missouri River’s Odor Study was used to calculate the total HAPs for the boilers. For the remaining emission factors, the U.S. EPA’s WebFIRE12 or AP-42 was used. The full-time usage of natural gas in the engines and boilers was also evaluated in case not enough digester gas would be generated to meet plant operational needs. The PTE for each of the digester scenarios indicated exceedances of the de minimis levels for carbon monoxide, nitrogen oxide, and total HAPs. There were no SMALs exceedances for digester gas combustion, but there were SMALs exceedances for natural gas combustion in the engines. Netting cannot be applied to this evaluation because both Lower Meramec and Grand Glaize are de minimis facilities. It is possible that the PTE exceedances could be resolved if design engineers provide lower emission factors than what was used. Using the information at hand, it was investigated whether permit throughput limits could be applied to avoid exceedances. It was determined that it would be possible to obtain a minor NSR permit for any of the scenarios, given that:  Design engineers provide lower emission factors for individual HAPs;  MSD uses digester gas throughput limits for the flare and boilers; and  MSD does not install internal combustion engines, unless design engineers can develop and guarantee lower emission factors. Quality Assurance HDR reviewed the initial set of calculations for Bissell Point and provided technical feedback. Ginny Hoppe (DEC) performed a detail check on all of the calculations. Ginny was provided with background information and sent the Excel spreadsheets with instructions for detail checking. All errors found in the detail check were discussed and fixed if applicable. Jay Hoskins reviewed the findings and provided feedback and oversight before the production of final deliverables.                                                              12 U.S. Environmental Protection Agency. Technology Transfer Network Clearinghouse for Inventories & Emission  Factors. <https://cfpub.epa.gov/webfire/>.  7    Conclusion It is feasible that MSD will be able to obtain air permits under the Minor NSR program for all of the sludge handling options being considered, pending certain design and permitting considerations. Although, for the Master Regional option, MSD is uncertain about how MDNR would respond to permitting an increased sludge throughput limit at Bissell Point. New sludge throughput limits should be allowed for the FBIs because they are new emission units. However, there could be environmental justice issues related to bringing a large amount of county sludge into the city for incineration. There also could be environmental justice issues with the Sub-Regional option, but this option is less risky because an increased sludge throughput at Bissell Point would not be necessary. For all incineration options, design engineers will need to develop dichlorobenzene and naphthalene emission factors specific to the FBIs installed to avoid permitting issues. Additionally, further consideration is needed to define the scope of ash handling projects associated with the FBIs. For the purpose of this evaluation, it was assumed that a new dry ash handling system would be installed and the wet ash handling system would be decommissioned. Bissell Point or Lemay should be able to obtain a Minor NSR permit with a new dry ash system if the dry ash lead emission factor is revised. MSD could develop a site-specific lead emission factor to avoid permitting issues. Another option would be to route ash handling emissions to the FBIs, if feasible for design. This is because FBIs have a fairly low lead emission limit that could be used as the dry ash lead emission factor. For the digester options, the permitting calculations will need to be updated to reflect actual combustion equipment design. However, MSD should be able to obtain a Minor NSR permit for any of the digester options given that: (1) design engineers provide lowered emission factors for individual HAPs; (2) MSD uses digester gas throughput limits for flares and boilers; and (2) MSD does not install internal combustion engines, unless design engineers can develop sufficiently low emission factors. Allowable Mercury Loading w/ Subpart MMMM Existing MHI Mercury Limit vs. Actual Loading Bissell Point WWTP Conversions 1 m3 =35.31 ft3 1 ton = 907.185 kg 1 yr = 525,600 min 1 lb = 453,592 mg 1 gal = 3.785 liters 1 yr = 365 days MHI ‐ Scrubber Removal Efficiency ‐ Mercury 9,618 dscfm (average from BT MHI stack tests) 41,355 dry tpy (average annual tpy over 10 years) 0.05 mg/dscm (average from 2015‐2017 stack tests) 7,313,429 mg/yr 0.19 mg/kg 0.22 mg/kg (avr. over 10 yrs) (vs. 0.23 mg/kg avr. from 2017 stack tests) 0.19 mg/kg (vs. 0.26 mg/kg avr. from 2017 stack tests) 0.03 mg/kg 11% CE (vs. 0% to 50.63 % CE from stack testing) MHI ‐ Hg Allowable Headworks Loading 0.28 mg/dscm 9,618 dscfm (estimated per BT MHI stack tests) 41,355 dry tpy (average annual dry tpy over 10 years) 37,516,568 kg/yr 50,699 MGY (per Doug Mendoza)*Update with recent flows from Pre‐treatment Group. 191,893,822,500 l/yr 74% 0.32 mg/dscm 1.2 mg/kg 0.0003 mg/l 0.37 lb/day 0.17 lb/day MHI ‐ Allowable Loading vs. Actual Loading *Use uniform allocation 138.9 MGD (per Doug Mendoza)*Update with recent flows from Pre‐treatment Group. 127.1 MGD (per Doug Mendoza) 11.8 MGD (per Doug Mendoza) 41,355 dry tpy (average annual dry tpy over 10 years) 0.0003 mg/l 0.03 lb/day 0.008 lb/day (based on 2007‐2013 data per Doug Mendoza) *Actual loading is < allowable loading 0.34 lb/day 0.0003 mg/l <0.0003 mg/l (based on 2007‐2013 data per Doug Mendoza) *Actual loading is < allowable loading Conclusion Exhaust Flow Rate = = Influent Hg Removal % = Emissions Prior to Scrubber = Allowable Sludge Concentration = (per Doug Mendoza; Doug noted that this value may be overestimating Hg removal from ww  to sludge) Allowable Influent Hg = Total Allowable Loading = 2007‐2013 Loading = Actual Residential Loading = The Subpart MMMM Hg limit is more limiting than the 40 CFR Part 503 Limit currently being used by the Pre‐Treatment program to set industrial  discharge mercury limits. However, it appears that the actual plant mercury loadings have been low enough to meet the Subpart MMMM limit.  Additional actual plant flows and throughputs need to be examined to complete this analysis. A lower mercury detection limit may be needed to  better quantify residential mercury loading. Average Annual WW Flow = Annual Throughput = Hg Emissions = = = Average Hg in Sludge = Average Hg Emissions = Hg Removed by Scrubbers = = Subpart MMMM Limit = Approximate Exhaust Flow = Average Annual Throughput =  = = Allowable Residential Loading = Plant Q = Residential Q = Industrial Q = Sludge Throughput = Actual Industrial Loading = Allowable Industrial Loading = Allowable Influent Conc. = 1 Allowable Mercury Loading w/ Subpart LLLL New FBI Mercury Limit vs. Actual Loading Bissell WWTP Conversions 1 m3 =35.31 ft3 1 ton = 907.185 kg 1 yr = 525,600 min 1 lb = 453,592 mg 1 gal = 3.785 liters 1 yr = 365 days FBI ‐ Hg Allowable Headworks Loading 0.0010 mg/dscm 18,000 dscfm (estimate per HDR) 41,355 dry tpy (average annual dry tpy over 10 years) 37,516,568 kg/yr 50,699 MGY (per Doug Mendoza)*Update with recent flows from Pre‐treatment Group. 191,893,822,500 l/yr 11% 74% 0.0011 mg/dscm 0.008 mg/kg 2.1E‐06 mg/L 0.002 lb/day 0.17 lb/day FBI ‐ Allowable Industrial & Residential Loading vs. Actual Loading *Use uniform allocation 138.9 MGD (per Doug Mendoza)*Update with recent flows from Pre‐treatment Group. 127.1 MGD (per Doug Mendoza) 11.8 MGD (per Doug Mendoza) 2.1E‐06 mg/l 0.0002 lb/day 0.008 lb/day (based on 2007‐2012 data per Doug Mendoza) *Actual loading exceeds allowable loading 0.002 lb/day 2.1E‐06 mg/l <0.0003 mg/l (based on 2007‐2012 data per Doug Mendoza) *Actual loading may exceed allowable loading Conclusion Residential Q = Allowable Influent Hg = 2007‐2013 Loading = Actual Industrial Loading = Allowable Residential Loading = = Actual Residential Loading = The mass balance indicates that Bissell FBIs may have issues complying with the Subpart LLLL mercury limit without carbon controls. The industrial  limit is currently based on 10 lb/day, with the actual average loading from 2007‐2013 being 0.008 lb/day. The industrial loading limit would need  to be decreased to around 0.0002 lb/day. A lower mercury detection limit would be needed to determine compliance, but I am not sure if a lower  detection limit is feasible. The lower detection limit would also be needed to quantify residential mercury loading for comparison to the Subpart  LLLL limit. Industrial Q = Allowable Industrial Loading = Plant Q = Total Allowable Loading = Subpart MMMM Limit = Emissions Prior to Scrubber = Estimated Hg CE = = Average Annual WW Flow =  = Average Annual Throughput = Influent Hg Removal % = Allowable Sludge Concentration = Approximate Exhaust Flow = Allowable Influent Conc. = (per Doug Mendoza; Doug noted that this value may be overestimating Hg removal from ww  to sludge) 2 Allowable Mercury Loading w/ Subpart MMMM Existing MHI Mercury Limit vs. Actual Loading Lemay WWTP Conversions 1 m3 =35.31 ft3 1 ton = 907.185 kg 1 yr = 525,600 min 1 lb = 453,592 mg 1 gal = 3.785 liters 1 yr = 365 days MHI ‐ Scrubber Removal Efficiency ‐ Mercury 7,390 dscfm (average from LT MHI stack tests) 18,388 dry tpy (average annual tpy over 10 years) 0.07 mg/dscm (average from 2015‐2016 stack tests) 7,936,493 mg/yr 0.48 mg/kg *Update with more lab data 0.40 mg/kg (avr. over 4 yrs)*(vs. 0.23 mg/kg avr. from 2017 stack tests) 0.48 mg/kg (vs. 0.17 mg/kg avr. from 2017 stack tests) ‐0.08 mg/kg ‐19% CE (vs. 5% and 77% CE from stack testing) MHI ‐ Hg Allowable Headworks Loading 0.28 mg/dscm 7,390 dscfm (average per LT MHI stack tests) 18,388 dry tpy (average annual dry tpy over 10 years) 16,681,553 kg/yr 47,012 MGY (per Doug Mendoza)*Update with recent flows from Pre‐treatment Group. 177,940,420,000 l/yr 74% 0.28 mg/kg 1.8 mg/kg 0.0002 mg/l 0.25 lb/day 0.74 lb/day MHI ‐ Allowable Industrial & Residential Loading *Use uniform allocation 128.8 MGD (per Doug Mendoza)*Update with recent flows from Pre‐treatment Group. 122.1 MGD (per Doug Mendoza) 6.7 MGD (per Doug Mendoza) 18,388 dry tpy 0.0002 mg/l MHI ‐ Allowable Loading vs. Actual Loading 0.01 lb/day 0.002 lb/day (based on 2007‐2012 data per Doug Mendoza) *Actual loading is < allowable loading 0.24 lb/day 0.0002 mg/l <0.0003 mg/l (based on 2007‐2012 data per Doug Mendoza) *Actual loading potentially is < allowable loading Conclusion Exhaust Flow Rate = Annual Throughput = Hg Emissions = = = = Average Hg in Sludge = Average Hg Emissions = Hg Removed by Scrubbers = = Allowable Influent Conc. = 2007‐2013 Loading = Subpart MMMM Limit = Approximate Exhaust Flow = Average Annual Throughput =  = Average Annual WW Flow = Allowable Sluge Conc. = Plant Q = Residential Q = Industrial Q = Sludge Throughput = Total Allowable Loading = Allowable Influent Hg = Allowable Industrial Loading = Actual Industrial Loading = (per Doug Mendoza; Doug noted that this value may be overestimating Hg removal from  ww to sludge) Allowable Residential Loading = = Actual Residential Loading = The Subpart MMMM Hg limit is more limiting than the 40 CFR Part 503 Limit currently being used by the Pre‐Treatment program to set  industrial discharge mercury limits. However, it appears that the actual plant mercury loadings are low enough to meet the Subpart MMMM  limit. Influent Hg Removal % = Emissions Prior to Scrubber = 1 Allowable Mercury Loading w/ Subpart LLLL New FBI Mercury Limit vs. Actual Loading Lemay WWTP Conversions 1 m3 =35.31 ft3 1 ton = 907.185 kg 1 yr = 525,600 min 1 lb = 453,592 mg 1 gal = 3.785 liters 1 yr = 365 days FBI ‐ Hg Allowable Headworks Loading 0.0010 mg/dscm 18,000 dscfm (estimate per HDR) 24,573 dry tpy (average annual dry tpy over 10 years) 22,292,080 kg/yr 47,012 MGY (per Doug Mendoza) 177,940,420,000 l/yr 0.01 mg/kg 5%(assumed) 0.01 mg/kg 74% 2.1E‐06 mg/l 0.002 lb/day 0.02 mg/kg FBI ‐ Allowable Industrial & Residential Loading vs. Actual Loading *Use uniform allocation 128.8 MGD (per Doug Mendoza)*Update with recent flows from Pre‐treatment Group. 122.1 MGD (per Doug Mendoza) 6.7 MGD (per Doug Mendoza) 24,573 dry tpy 2.1E‐06 mg/l 0.0001 lb/day 0.002 lb/day (based on 2007‐2012 data per Doug Mendoza) *Actual loading exceeds allowable loading 0.002 lb/day 2.1E‐06 mg/l <0.0003 mg/l (based on 2007‐2012 data per Doug Mendoza) *Actual loading may exceed allowable loading Conclusion Total Allowable Loading = The mass balance indicates that Lemay FBIs may have issues complying with the Subpart LLLL mercury limit without carbon controls. The  industrial limit is currently based on 10 lb/day, with the actual average loading from 2007‐2013 being 0.002 lb/day. The industrial loading  limit would need to be decreased to around 0.0001 lb/day. A lower mercury detection limit would be needed to determine compliance, but I  am not sure if a lower detection limit is feasible. The lower detection limit would also be needed to quantify residential mercury loading for  comparison to the Subpart LLLL limit. Allowable Industrial Loading = Actual Industrial Loading = Allowable Residential Loading = = Actual Residential Loading = Plant Q = Residential Q = Industrial Q = Sludge Throughput = Allowable Influent Conc. = Allowable Conc. w/ Scrubber = Estimated Hg CE = Allowable Emissions Before  Scrubber = Influent Hg Removal % = Allowable Influent Conc. = Allowable Sludge Conc. = = (per Doug Mendoza; Doug noted that this value may be overestimating Hg removal from  ww to sludge) Subpart MMMM Limit = Approximate Exhaust Flow = Average Annual Throughput =  = Average Annual WW Flow = 2 Appendix I – Planning Studies on Forcemain Alignments and Cost Estimates Page 1 of 3 Sludge Transfer Forcemain: Grand Glaize WWTF to Lower Meramec WWTF (13077) MSD staff has been evaluating solids handling options at the various treatment plants throughout the District. Several alternatives were considered and it was determined that the most cost effective and efficient method to handle solids was to incinerate at two sub-regional facilities: one at the Lemay WWTF; and another at the Bissell WWTF. Under this scenario, the sludge from the Lower Meramec Service Area (Grand Glaize, Fenton and Lower Meramec) would be processed at the Lemay WWTF. Raw sludge from the Lower Meramec Service Area would be transported to the Lower Meramec WWTF and from there to the proposed Lemay Solids Processing Facility. Sludge from Grand Glaize and Fenton would be transported via pump stations, forcemains and gravity sewers, including the Riverside/Yarnell Trunk Sewer and Phase II of the Lower Meramec Tunnel, which is currently in design (MSD Project 11746) and expected to be placed in service in 2024. Sludge from the Grand Glaize WWTF will be transported to the Riverside-Yarnell Trunk Sewer by means of pump stations and forcemains. This will require two new pump stations and approximately 23,400 linear feet of 6-inch high density polyethylene (HDPE) pipe. The pump stations and forcemains will be sized to transport 3,200 dry tons of thickened sludge per year generated at Grand Glaize. At approximately 2% solids this equates to 160,000 wet tons per year (105,125 gpd or 0.16 cfs). Upon discharge to the Riverside/Yarnell Trunk Sewer, it will flow by gravity to the Phase II extension of the Lower Meramec Tunnel and then by tunnel to the Lower Meramec WWTF. It should be noted that once the Lower Meramec Tunnel is in service, the Fenton WWTF will be decommissioned and all flow tributary to this facility will be directed to the Lower Meramec Tunnel. The proposed alignment for the forcemains (see attached Figure) from the Grand Glaize WWTF to the Riverside/Yarnell Trunk Sewer was chosen based on the location of the shortest route while staying within public right-of-way or existing easements. The alignment begins at the Grand Glaize WWTF and follows the route of the existing 24-inch Chrysler/Sub-5 forcemain, then under the Meramec River to the old Chrysler Plant site. It proceeds south along Hitzert Court to the north outer road of Interstate 44. It crosses under I-44 at Fabick Drive and runs south to Fabricator Drive. It then jogs to east to Headland Drive, then runs south along Headland to Riverside Drive, then south along Riverside Drive to the Riverside/Yarnell trunk sewer on the south side of Larkin Williams Road. EPANET (software that models the hydraulics and water quality within pressurized pipe networks) and MSD base map contours (used for ground elevations) were used for preliminary design. It was determined that two pump stations would be needed to convey the sludge. A Hazen-Williams “C” value of 110 was selected for HDPE pipe. One pump station would be located in the vicinity of the Grand Glaize WWTF and the other in vicinity of the existing “Chrysler/Sub-5” pump station, west of the Meramec River on the old Chrysler Plant site. The pump stations should have the capacity to pump approximately 250 gpm (0.36 mgd) at 135 feet of head with two 30 HP pumps. Variable frequency drive (VFD) motors are recommended for Page 2 of 3 the pumps. 6-inch HDPE pipe (SDR II) is recommended for the forcemain. The average velocities in the forcemain would range from 2.5 to 3.0 feet per second. The maximum system pressure is approximately 130 psig. Four combination air release valves (CARV) are required. Conceptual cost estimates were developed using “BMP-4 – Cost Estimating” prepared by Jacobs Engineering. The itemized costs (2017 dollars) are summarized in the table below. 2017 Costs Description Unit Cost (per lf) Length (lf) Total Cost Open Cut $192 21,400 $4,108,800 Tunnel $900 2,000 $1,800,000 Pump Stations $600,000 2 $1,200,000 Sub-Total $7,108,800 15% Utility Relocation $1,066,320 30% Construction Contingency $2,132,640 Total $10,307,760 20% Design $2,061,552 Total $12,369,312 Rounded Total: $12,370,000 Extending the unit costs to 2024 dollars increases the project total to $13,500,000. Page 3 of 3 Figure 1 – Forcemain Alignment Page 1 of 3 Sludge Transfer Forcemain: Lower Meramec WWTF to Lemay WWTF MSD staff has been evaluating solids handling options at the various treatment plants throughout the District. Several alternatives were considered and it was determined that the most cost effective and efficient method to handle solids was to incinerate at two sub-regional facilities: one at the Lemay WWTF; and another at the Bissell WWTF. Under this scenario, the sludge from the Lower Meramec Service Area (Grand Glaize, Fenton and Lower Meramec) would be processed at the Lemay WWTF. Raw sludge from the Lower Meramec Service Area would be transported to the Lower Meramec WWTF and from there to the proposed Lemay Solids Processing Facility. Sludge from Grand Glaize and Fenton would be transported via pump stations, forcemains and gravity sewers, including the Riverside/Yarnell Trunk Sewer and Phase II of the Lower Meramec Tunnel, which is currently in design (MSD Project 11746) and expected to be placed in service in 2024. Sludge from the Lower Meramec WWTF will be transported to the Lemay WWTF by means of pump stations and forcemains. This will require three new pump stations and approximately 53,250 linear feet of 6-inch high density polyethylene (HDPE) pipe. The pump stations and forcemains will be sized to transport 6,120 dry tons of thickened sludge per year (3,126 generated at Grand Glaize, 1,000 generated at Fenton and 1,995 generated at Lower Meramec). At approximately 2% solids this equates to 306,000 wet tons per year (201,000 gpd or 0.31 cfs). The proposed alignment for the forcemains (see attached Figure) from the Lower Meramec WWTF to the Lemay WWTF was chosen based on the location of the shortest route while staying within public right-of-way or existing easements. The alignment chosen travels from the Lower Meramec WWTF, north along Telegraph Road, northeast along Kingston Dr, and north/northeast along Broadway Street until reaching the Lemay WWTF. Tunneling approximately 2,000 feet underneath Interstate 255 will be required and is incorporated in the final cost estimate. The alignment is taken to the WWTF property line. EPANET (software that models the hydraulics and water quality within pressurized pipe networks) and MSD base map contours (used for ground elevations) were used for preliminary design. It was determined that three pump stations would be needed to convey the sludge. A Hazen-Williams “C” value of 110 was selected for HDPE pipe. One pump station would be located in the vicinity of the Lower Meramec WWTF, another in the vicinity of Becker Road and Telegraph Road and the other in the vicinity of Forder Road and Telegraph Road. The Lower Meramec WWTF pump station should have the capacity to pump 250 gpm (0.36 mgd) at 240 feet of head with two 50 HP pumps. The Becker Road and Telegraph Road pump station should have the capacity to pump 250 gpm at 140 feet of head with two 30 HP pumps. The Forder Road and Telegraph Road pump station should have the capacity to pump 250 GPM at 230 feet of head with two 40 HP pumps. Variable frequency drive (VFD) motors are recommended for the pumps. 6-inch HDPE pipe (SDR II) is recommended for the forcemain. The average velocities in the forcemain would range from 2.5 to 3.0 feet per second. The maximum system pressure is approximately 130 psig. Eight combination air release valves (CARV) are required. Page 2 of 3 Conceptual cost estimates were developed using “BMP-4 – Cost Estimating” prepared by Jacobs Engineering. The itemized costs (2017 dollars) are summarized in the table below. 2017 Costs Description Unit Cost (per lf) Length (lf) Total Cost Open Cut $192 51,250 $9,840,000 Tunnel $900 2,000 $1,800,000 Pump Stations $600,000 3 $1,800,000 Sub-Total $13,440,000 15% Utility Relocation $2,020,000 30% Construction Contingency $4,040,000 Total $19,500,000 20% Design $3,900,000 Total $23,400,000 Rounded Total: $23,400,000 Extending the unit costs to 2024 dollars increases the project total to $28,000,000. Page 3 of 3 Figure 1 – Forcemain Alignment Appendix J – FBI Alternatives Cost and Application Notes Biosolids Handling Master PlanAlernative Comparison SummaryCapital Cost Estimate (2017)Cost from least cost option% difference from least cost optionMaster RegionalFluidized bed incinerators (FBI) at BT, sized for BT, LT, CT, GT, and JT(+FT)CT: redundant forcemain LT: PS & FM to BT, plant to plantJT: PS & FM from to LT, plant‐to‐plantGT: PS and FM to JT tunnelMT: no change$360,000,000‐0%Medium UncertaintyCapital cost ($60M) for forcemain from Lemay to Bissell needs further study.Plant‐to‐plant JT/LT FM estimated at $24M, defers $80M in Lemay nutrient upgrades.New infrastructure     *1 FBI     *PS & FM assetsLess labor than presentLower emissions overall Permitting Issue: BT needs throughput limit increase Sub‐Regional:JT Digester OnlyFBI at BT, sized for BT, LT, & CT.CT: redundant forcemain LT: PS & FM to BT, plant to plantJT(+FT): new anaerobic digesterGT: PS and FM to JT tunnelMT: no change$380,000,000$20,000,000 6%Sub‐Regional:JT & GT Digesters FBI at BT, sized for BT, LT, & CT.CT: redundant forcemain LT: PS & FM to BT, plant to plantJT(+FT): new anaerobic digesterGT: new anaerobic digesterMT: no change$380,000,000$20,000,000 6%City‐County IncinerationFBI at BT, sized for BT & CTFBI at LT, sized for LT, GT, and JT(+FT)CT: redundant forcemain JT: PS & FM to LT, plant‐to‐plantGT: PS & FM to JT tunnelMT: no change$390,000,000$30,000,000 8%Lowest UncertaintyCould design‐build lower capital cost?Plant‐to‐plant JT‐to‐LT  FM defers future nutrient upgrade costs.New infrastructure     *2 FBIs     *PS & FM assetsSimilar labor to presentOperation redundancyLower emissions overall, and LT and BT.  Permitting is straightforwardGeneral concerns about incineration, but nothing unusual anticipated.Potential concerns about consolidating incineration at BTLT‐to‐BT FM: spills and odors in high risk area.Lower emissions overallPermitting issue: new Title V (air) permits at  JT & GT.Community EffectsAlternative DescriptionAlternative NameCapital cost comparisonsO&M ComparisonCost UncertaintyEnvironmental Benefits/ImpactsMedium UncertaintyIncinerator capital costs may be high, savings potential. (<$30M)Lemay to Bissell forcemain needs study (see above).  New infrastructure     *1 FBI     *1 or 2 digesters     *PS & FM assetsMore labor than present Master RegionalCost ComponentsComponent Description Capital Cost Information Source for CostAssumptions Comments/ExplanationBissell Point FBI$257,274,880B&V Solids Handling Plan. 2010 dollars, Table 6‐25, adjusted to 2017 dollars.*FBI faciilty sized to accept all sludge, except for Mo River sludge.  Need 75,322 dtpy capacity. *131,000 dtpy provided by 3 units operating 24‐7. Requires MDNR to allow increase in throughput without requiring major modification construction permit. Need to bring dry ash handling emissions through incinerator scrubbers (Fed. Enforceable)2 units provides sufficient capacity (87,600 dtpy, 24‐7 operation), however, we assumed that 3 large units would be needed, 2 units in operation and 1 in standby. 3 units would provide additional redundancy that, in a regional facility, could be beneficial. This cost and capacity presented here is consistent with B&V's study. Sludge Conveyance from Coldwater to Bissell$8,791,040B&V Solids Handling Plan. 2010 dollars, TM‐6, cost tables for S‐3, adjusted to 2017 dollars*Provide redundant forecemain to allow continued pumping of raw sludge into Bissell tunnell.B&V solids handling study assumed a new pump station and forcemain would be needed to move Coldwater solids into the Bissell collection system.  Asset replacement is not needed today. Funds were included here to provide a redundant forcemain. Sludge Conveyance from Lemay to Bissell$62,054,400B&V Solids Handling Plan. 2010 dollars, TM‐6, cost tables for S‐3, adjusted to 2017 dollars*Transports solids from the Lemay plant to the Bissell plant for incineration.*Solids in the forcemain would be generated by Lemay, Lower Meramec, and Grand Glaize plants (28,200 dtpy, @ 2% solution is approx 1 MGD.)*Assumes future nutrient controls will be implemented at Bissell Point, and that the additional costs for dealing with nutrients from these solids is not substantial.The B&V study provided a cost ($48.5M) for a forcemain and pump station system. The study implies this FM runs plant‐to‐plant. The study did not provide an alignment or other details, and it's unclear if the cost includes property and easement aquisition.  Since it would go from plant to plant, there would be no need for wet‐weather solids storage at Lemay.If sludge was discharged into the BT tunnel, the the BT headworks would need to be upgraded and wet weather storageprovided. No cost on headworks upgrade is provided by B&V, but study says it would be required. Also, potential water quality issues from CSOs. For reference only, if Lemay's sludge is taken to the Bissell tunnel, wet‐weather storage at Lemay could run $4M for 3M gal storage. Planning also provided a preliminary look for a forcemain between Lemay and Bissell (plant to plant).  The alignment for the route is generally along Lemay Ferry Road and Grand Avenue, and there would be no need for wet‐weather solids storage at Lemay. Approx 10 miles of 6" dia FM, 1.6 miles of 6" pipe in tunnel, and 4 pump stations would be needed. Planning presented a cost of $38.7M, 2017 dollars. This cost does not include modifications to Bissell or Lemay plants for handling solids, easement costs, or property aquistion costs, all of which would be substantial. The B&V study's estimate was used as the basis of the cost presented herein. There is signficant uncertainty in the cost estimate for forcemain from Lemay to Bissell and a complete study of this component is needed should it move forwardin any alternative.Sludge Conveyance from Lower Meramec to Lemay$23,400,000 Planning Study, 2017 costs*Transports solids from the Lower Meramec plant to the Lemay plant. *Solids in the forcemain would be generated by Lower Meramec and Grand Glaize plants. Fenton is off‐line when this plan is in place, so the solids generated at Lower Meramec include the Fenton solids. Assume incremental solids generation at Lower Meramec is similar to what is generated now at Fenton. (7200 dtypy, @ 2% solution is approx 0.3 MGD.)*FM alignment should be plant to plant to avoid future upgrades for nutrient controls (i.e., do not take sludge into Lemay headworks). Construction of the FM from plant‐to‐plant avoids  $80M of future nutrient capital costs and $12M of O&M (2017 dollars) at Lemay WWTP, as well as the operational challenges of operating nutrient controls at a CSO/blending plant with weak influent, and possible upgrades to Lemay's headworks. Alignment generally follows Telegraph Road. This plan includes approximately 10 miles of 6" dia FM, 0.5 miles of 6" pipe in tunnel, and 3  pump stations. Cost estimate does not include modifications at the treatment plants, easement or property acquistion. Estimate seems to be in‐line with cost of forcemain from Bridgeton Landfill to Bissell sewershed (about the same distance as Lower Meramec to Lemay).Sludge Conveyance from Grand Glaize to Lower Meramec$13,000,000Planning Study, 2017 costs*Transports solids from Grand Glaize plant to Lower Meramec collection system. (3500 dtpy @ 2% solution is approx 0.13 MGD.)*Utilizes existing FM under Meramec River as carrier.*Fenton is off‐line, tunnel from Fenton to Lower Meramec is available and can receive solids from Grand Glaize. *Assumes future nutrient controls will be in place at Lower Meramec and that the additional cost for dealing with nutrients in solids is marginal.Alignment would connect forcemain at the Fenton drop shaft. May be able to reduce this cost by connecting to trunk sewer in sewershed. Subtotal$364,520,320 Sub‐Regional: JT Digester OnlyCost ComponentsComponent Description Capital Cost Source of CostAssumptions Comments/ExplanationBissell Point FBI$257,274,880B&V Solids Handling Plan. 2010 dollars, Table 6‐25, adjusted to 2017 dollars.*FBI facility sized for Bissell, Lemay, and Coldwater only. Need 68,000 dtpy.*131,000 dtpy capacity provided by 3 large (120 dtph) units, or 113,080 dtpy provided by 2 large units (120 dtph) and one smaller (70 dtph) unit. Minor modification air construction permit is likely. Simpler permitting scenario relative to "Master Regional". Need to bring dry ash handling emissions through incinerator scrubbers (Fed. Enforceable)2 large units provides sufficient capacity (120 dtph each @ 2 @ 24‐7 operation = 87,600 dtpy).  A 3rd unit is needed for maintenance. With the slighly lower throughput in this scenario, the 3rd unit could potentially be a smaller 70 dtph unit. We don't have a cost for 2‐120 dtph units and 1‐70 dtph unit. So, we used the cost for 3 large units, which was available in B&V's estimate for 3 large units. Capacity (and cost, presumably) for this component is probably greater than actual. Using a scaling factor ($1,072,064/dtph capacity) from Lemay's capital cost,  with the cost of a 2 unit system at Bissell ($150,089,000), and 70 dtph, capital cost would be around $225M (potential $25M savings)Coldwater Sludge Conveyance to Bissell$8,791,040B&V Solids Handling Plan. 2010 dollars, TM‐6, cost tables for S‐3, adjusted to 2017 dollars.*Provide redundant forecemain to allow continued pumping of raw sludge into Bissell tunnell.B&V solids handling study assumed a new pump station and forcemain would be needed to move Coldwater solids into the Bissell collection system.  Note that asset replacement is not needed today. These funds were included here to provide a redundant forcemain. Sludge Conveyance from Lemay to Bissell$62,054,400B&V Solids Handling Plan. 2010 dollars, TM‐6, cost tables for S‐3, adjusted to 2017 dollars*Transports solids from the Lemay plant to the Bissell plant for incineration.*Solids in the forcemain would be generated by Lemay, Lower Meramec, and Grand Glaize plants (28,200 dtpy, @ 2% solution is approx 1 MGD.)*Assumes future nutrient controls will be implemented at Bissell Point, and that the additional costs for dealing with nutrients from these solids is not substantial.The B&V study provided a cost ($48.5M) for a forcemain and pump station system. The study implies this FM runs plant‐to‐plant. The study did not provide an alignment or other details, and it's unclear if the cost includes property and easement aquisition.  Since it would go from plant to plant, there would be no need for wet‐weather solids storage at Lemay.If sludge was discharged into the BT tunnel, the the BT headworks would need to be upgraded and wet weather storage provided. No cost on headworks upgrade is provided by B&V, but study says it would be required. Also, potential water quality issues from CSOs. For reference only, if Lemay's sludge is taken to the Bissell tunnel, wet‐weather storage at Lemaycould run $4M for 3M gal storage. Planning also provided a preliminary look for a forcemain between Lemay and Bissell (plant to plant).  The alignment for the route is generally along Lemay Ferry Road and Grand Avenue, and there would be no need for wet‐weather solids storage at Lemay. Approx 10 miles of 6" dia FM, 1.6 miles of 6" pipe in tunnel, and 4 pump stations would be needed. Planning presented a cost of $38.7M, 2017 dollars. This cost does not include modifications to Bissell or Lemay plants for handling solids, easement costs, or property aquistion costs, all of which would be substantial. The B&V study's estimate was used as the basis of the cost presented herein. There is signficant uncertainty in the cost estimate for forcemain from Lemay to Bissell and a complete study of this component is needed should it move forward in any alternative.Sludge digester at Lower Meramec$34,000,000 HDR Odor Control Study*Construction of anaerobic digster at Lower Meramec, sized for current solids production at Lower Meramec, Fenton, and Grand Glaize plants. (7200 dtpy).*Air permit can be obtained as minor modification construction permit. *New Title V operating permit for Lower Meramec, moving forward.*Digester gas is flared or otherwise consumed at Lower Meramec (not sold back for credits).Still need disposal or land application of digester sludge. DEC construction permit assessment: likely a minor modification with a throughput limit. New Title V permit. Title V will be more restrictive operationally (e.g., throughput limit on flare, boilers probably ok, but likely no engines). Sludge Conveyance from Grand Glaize to Lower Meramec$13,000,000Planning Study, 2017 costs*Transports solids from Grand Glaize plant to Lower Meramec collection system. (3500 dtpy @ 2% solution is approx 0.13 MGD.)*Utilizes existing FM under Meramec River as carrier.*Fenton is off‐line, tunnel from Fenton to Lower Meramec is available and can receive solids from Grand Glaize. *Assumes future nutrient controls will be in place at Lower Meramec and that the additional cost for dealing with nutrients in solids is marginal.Alignment would connect forcemain at the Fenton drop shaft. May be able to reduce this cost by connecting to trunk sewer instead.  Subtotal$375,120,320placeholder until HDR study is complete Sub‐Regional: JT and GT Digesters Cost ComponentsComponent Description Capital Cost Source of CostAssumptions Comments/ExplanationBissell Point FBI$257,274,880B&V Solids Handling Plan. 2010 dollars, Table 6‐25, adjusted to 2017 dollars.*FBI facility sized for Bissell, Lemay, and Coldwater only. Need 68,000 dtpy.*131,000 dtpy capacity provided by 3 large (120 dtph) units, or 113,080 dtpy provided by 2 large units (120 dtph) and one smaller (70 dtph) unit. Minor modification air construction permit is likely. Simpler permitting scenario relative to "Master Regional". Need to bring dry ash handling emissions through incinerator scrubbers (Fed. Enforceable)2 large units provides sufficient capacity (120 dtph each @ 2 @ 24‐7 operation = 87,600 dtpy).  A 3rd units is needed for maintenance. With the slighly lower throughput in this scenario, the 3rd unit could potentially be a smaller 70 dtph unit.We don't have a cost for 2‐120 dtph units and 1‐70 dtph unit. So, we used the cost for 3 large units, which was available in B&V's estimate for 3 large units. Capacity (and cost, presumably) for this component is probably greater than actual. Coldwater Sludge Conveyance to Bissell $8,791,040B&V Solids Handling Plan. 2010 dollars, TM‐6, cost tables for S‐3, adjusted to 2017 dollars.*Provide redundant forecemain to allow continued pumping of raw sludge into Bissell tunnell.B&V solids handling study assumed a new pump station and forcemain would be needed to move Coldwater solids into the Bissell collection system.  Note that asset replacement is not needed today. These funds were included here to provide a redundant forcemain.Sludge Conveyance from Lemay to Bissell$62,054,400B&V Solids Handling Plan. 2010 dollars, TM‐6, cost tables for S‐3, adjusted to 2017 dollars*Transports solids from the Lemay plant to the Bissell plant for incineration.*Solids in the forcemain would be generated by Lemay, Lower Meramec, and Grand Glaize plants (28,200 dtpy, @ 2% solution is approx 1 MGD.)*Assumes future nutrient controls will be implemented at Bissell Point, and that the additional costs for dealing with nutrients from these solids is not substantial.The B&V study provided a cost ($48.5M) for a forcemain and pump station system. The study implies this FM runs plant‐to‐plant. The study did not provide an alignment or other details, and it's unclear if the cost includes property and easement aquisition.  Since it would go from plant to plant, there would be no need for wet‐weather solids storage at Lemay.If sludge was discharged into the BT tunnel, the the BT headworks would need to be upgraded and wet weather storageprovided. No cost on headworks upgrade is provided by B&V, but study says it would be required. Also, potential water quality issues from CSOs. For reference only, if Lemay's sludge is taken to the Bissell tunnel, wet‐weather storage at Lemay could run $4M for 3M gal storage. Planning also provided a preliminary look for a forcemain between Lemay and Bissell (plant to plant).  The alignment for the route is generally along Lemay Ferry Road and Grand Avenue, and there would be no need for wet‐weather solids storage at Lemay. Approx 10 miles of 6" dia FM, 1.6 miles of 6" pipe in tunnel, and 4 pump stations would be needed. Planning presented a cost of $38.7M, 2017 dollars. This cost does not include modifications to Bissell or Lemay plants for handling solids, easement costs, or property aquistion costs, all of which would be substantial. The B&V study's estimate was used as the basis of the cost presented herein. There is signficant uncertainty in the cost estimate for forcemain from Lemay to Bissell and a complete study of this component is needed should it move forwardin any alternative.Sludge digester at Lower Meramec$29,000,000 HDR Odor Control Study*Construction of anaerobic digster at Lower Meramec, sized for current solids production at Lower Meramec and Fenton plants. (3700 dtpy).*Air permit can be obtained as minor modification construction permit. *New Title V operating permit for Lower Meramec, moving forward.*Digester gas is flared or otherwise consumed at Lower Meramec (not sold back for credits).Still need disposal or land application of digester sludge. DEC construction permit assessment: likely a minor modification with a throughput limit. DEC (new) Title V permit assessment: likely a minor modification with a (flexible) throughput limit. Sludge digester at Grand Glaize$22,000,000 HDR Odor Control Study*Construction of anaerobic digster at Lower Meramec, sized for current solids production at Lower Meramec and Fenton plants. (3500 dtpy).*Air permit can be obtained as minor modification construction permit. *New Title V operating permit for Grand Glaize, moving forward.*Digester gas is flared or otherwise consumed at Lower Meramec (not sold back for credits). Still need disposal or land application of digester sludge. DEC construction permit assessment: likely a minor modification with a throughput limit. DEC (new) Title V permit assessment: likely a minor modification with a (flexible) throughput limit. Subtotal$379,120,320placeholder until HDR study is complete City‐County IncinerationCost ComponentsComponent Description Capital CostSource of CostAssumptions Comments/ExplanationBissell Point FBI$187,761,920B&V Solids Handling Plan. 2010 dollars, Table 1‐34, adjusted to 2017 dollars.*FBI facility sized for Bissell and Coldwater only. Need 48,000 dtpy. *2 FBI units @ 120 dtpd each provides 87,000 dtpy (24‐7 operation). *Units could be taken down for maintenance during times of reduced flows/loading, without a need of a 3rd unit for shutdown periods. *B&V study recommended 2 units @ 120 dtpd each. *MT costs for decomissioning facilities, estimated at $200,000, were not extracted from B&V costs.*Need to bring dry ash handling emissions through incinerator scrubbers (fed. Enforceable)*Assumed 2 units is as few as feasible, to provide redundancy.Lemay FBI$153,061,120B&V Solids Handling Plan. 2010 dollars, Table 2‐34, adjusted to 2017 dollars.*FBI faciilty sized for Lemay, Lower Meramec, Grand Glaize, and Fenton (off‐line). Need 28,000 dtpy capacity. *Capital costs are bases on 2 FBI Lemay units (70 dtph each @ 2 @ 24‐7 operation = 51,100 dtpy). B&V study did not assess accepting Lower Meramec and Grand Glaize sludge at Lemay, but it appears that the facility would have capacity. Lemay should be able to handle total throughput (5.83 dtph, average) under currently permitted throughput (7.41 dtph, daily average).O&M costs are likely greater than those in B&V study, becuase B&V assumed facility would be operated 5 days/week. Sludge Conveyance from Lower Meramec to Lemay$23,400,000Planning Study, 2017 costs*Transports solids from the Lower Meramec plant to the Lemay plant. *Solids in the forcemain would be generated by Lower Meramec and Grand Glaize plants. Fenton is off‐line when this plan is in place, so the solids generated at Lower Meramec include the Fenton solids. Assume incremental solids generation at Lower Meramec is similar to what is generated now at Fenton. (7200 dtypy, @ 2% solution is approx 0.3 MGD.)*FM alignment should be plant to plant to avoid future upgrades for nutrient controls (i.e., do not take sludge into Lemay headworks). Construction of the FM from plant‐to‐plant avoids  $80M of future nutrient capital costs and $12M of O&M (2017 dollars) at Lemay WWTP, as well as the operational challenges of operating nutrient controls at a CSO/blending plant with weak influent, and possible upgrades to Lemay's headworks. Alignment generally follows Telegraph Road. This plan includes approximately 10 miles of 6" dia FM, 0.5 miles of 6" pipe in tunnel, and 3  pump stations. Cost estimate does not include modifications at the treatment plants, easement or property acquistion. Estimate seems to be in‐line with cost of forcemain from Bridgeton Landfill to Bissell sewershed (about the same distance as Lower Meramec to Lemay).Sludge Conveyance from Grand Glaize to Lower Meramec (option 2)$13,000,000Planning Study, 2017 costs*Transports solids from Grand Glaize plant to Lower Meramec collection system. (3500 dtpy @ 2% solution is approx 0.13 MGD.)*Utilizes existing FM under Meramec River as carrier.*Fenton is off‐line, tunnel from Fenton to Lower Meramec is available and can receive solids from Grand Glaize. *Assumes future nutrient controls will be in place at Lower Meramec and that the additional cost for dealing with nutrients in solids is marginal.Alignment would connect forcemain at the Fenton drop shaft. May be able to reduce this cost by connecting to trunk sewer in sewershed. Subtotal$386,014,080