HomeMy Public PortalAboutPKT-CC-2010-10-12CITY OF MOAB
October 12, 2010
PRESENTATION 5:30 PM
PRE-COUNCIL WORKSHOP
6:30 PM
REGULAR COUNCIL MEETING
7:00 PM
CITY COUNCIL CHAMBERS
(217 East Center Street)
Page 1 of 135
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Moab City CouncilMaster Meeting Calendar*110/8/2010 2:10 PM*Meeting end times are approximations onlyMoab City Recorder's OfficeSMTWT F S12345678910 11 12 13 14 15 1617 18 19 20 21 22 2324 25 26 27 28 29 3031October 2010SMTWT F S1234567 8 9 10 11 12 1314 15 16 17 18 19 2021 22 23 24 25 26 2728 29 30November 2010October 2010Sep 26 - Oct 2Sep 2627282930Oct 12Oct 3 - 934567896:00pm 7:00pm GCAB3:00pm 4:00pm GC Counci5:00pm 6:00pm KZMU Boa7:00pm 9:00pm GC Counci7:00pm 9:00pm CVTC3:00pm 4:00pm GCSWSSD3:30pm 4:00pm MARC7:00pm 9:00pm GWSSAOct 10 - 161011121314151612:30pm 2:00pm GCCOA3:00pm 4:00pm GCSDBE W3:00pm 3:30pm MVFPD6:30pm 9:00pm Moab CC6:00pm 7:00pm GC PC7:00pm 8:00pmTSSD6:30pm 8:00pm Moab PC7:00pm 8:00pm CVFPOct 17 - 23171819202122233:00pm 4:00pm GC Counci7:00pm 9:00pm GC Counci5:00pm 6:30pm GCLB6:00pm 7:00pm GCSDBE6:00pm 6:30pm GCRSSDOct 24 - 302425262728293012:00pm 12:30pm MTPSC6:30pm 9:00pm Moab CC6:00pm 7:00pm GC PC6:00pm 6:30pm Joint CC/PC6:30pm 8:00pm Moab PCOct 31 - Nov 631Nov 123456SundayMondayTuesdayWednesdayThursdayFridaySaturdayPage 3 of 135
EntryFull DescriptionMeeting LocationDatesCHCSSDCanyonlands Health Care Special Service District Grand Center #4Last ThursdayCVFPCastle Valley Fire ProtectionCommunity Center #2 Castle Valley Drive 2nd ThursdayCVPCCastle Valley Planning CommissionCommunity Center #2 Castle Valley Drive 1st WednesdayCVTCCastle Valley Town CouncilCommunity Center #2 Castle Valley Drive 3rd WednesdayGCCMDGrand County Cemetary Maintenance DistrictSunset Memorial Cemetary2nd TuesdayGC Council Meeting Grand County Council Meeting125 East Center Street1st & 3rd TuesdayGCABGrand County Airport Board125 East Center Street2nd TuesdayGCCOAGrand County Council on AgingGrand Center2nd MondayGCHECGrand County Higher Education CommitteeUSU Extension Office4th ThursdayGCHPCGrand County Historic Preservation Committee Grand Center4th WednesdayGCLBGrand County Library Board257 East Center Street2nd WednesdayGCPCGrand County Planning Commission125 East Center Street2nd & 4th WednesdayGCRSSDGrand County Recreation Special Service District 217 East Center Street2nd WednesdayGCSDBEGrand County School District Board of Education 264 South 400 East3rd WednesdayGCSWSSD Grand County Solid Waste Special Service District 100 Sand Flats Road1st ThursdayGCWBGrand County Weed BoardGrand Center1st MondayGWSSAGrand Water & Sewer Service Agency3025 East Spanish Trail Road1st & 3rd ThursdayLPCLegislative Policy CommitteeUtah Local Governments Trust No. SLC 3rd MondayMARCMoab Arts and Recreation Center Advisory Board 111 E. 100 North1st ThursdayMATCABMoab Area Travel Council Advisory Board125 East Center Street4th ThursdayMC Council Meeting Moab City Council Meeting217 East Center Street2nd & 4th TuesdayMCPCMoab City Planning Commission217 East Center Street2nd & 4th ThursdayMMADMoab Mosquito Abatement Distrcit1000 East Sand Flats Road1st or 2nd ThursdaySEUALGSouth Eastern Utah Association of Local Government Price2nd ThursdaySEUDHDSouth Eastern Utah District Health Department Green River City OfficesTRAIL MIXTrail MixGrand Center2nd Tuesday noonTSSDThompson Special Service DistrictThompson Springs Fire Station2nd TuesdayTSSFDThompson Special Service Fire DistrictThompson Springs Fire Station2nd ThursdayPage 4 of 135
City of Moab – Regular Council Meeting
City Council Chambers: 217 East Center Street
Tuesday, October 12, 2010 at 7:00 p.m.
5:30 p.m. MOAB WASTEWATER FACILITIES PLANNING REVIEW
6:30 p.m. PRE‐COUNCIL WORKSHOP
7:00 p.m. CALL TO ORDER AND PLEDGE OF ALLEGIANCE
SECTION 1: APPROVAL OF MINUTES
1‐1 August 24, 2010
1‐2 September 14, 2010
1‐3 September 28, 2010
SECTION 2: CITIZENS TO BE HEARD
SECTION 3: DEPARTMENTAL UPDATES
3‐1 Community Development Department
3‐2 Engineering Department
3‐3 Planning Department
3‐4 Police Department
3‐5 Public Works Department
SECTION 4: PRESENTATIONS
4‐1 Presentation by the Utah Division of Water Quality Regarding Nutrient
Removal Cost Impact Study
SECTION 5: NEW BUSINESS
5‐1 Approval of Proposed Resolution #18‐2010 – A Resolution Accepting the
Public Improvements Installed for the Extension of the Sewer System
Associated with the North Area Trunk Sewer Project and Authorizing the
Appropriate Parties to Execute and Deliver a Corresponding Sewer Line
Dedication, Easement and Warranty of Improvements
5‐2 Approval of a Relinquishment of a Temporary Construction Easement for the
North Area Trunk Sewer
City of Moab
217 East Center Street
Moab, Utah 84532
Main Number (435) 259‐5121
Fax Number (435) 259‐4135
www.moabcity.org
Page 5 of 135
5‐3 Approval of a Two‐lot Minor Subdivision for Property Located at 420 Kane
Creek Boulevard and Located in the I‐1 Industrial Zone
5‐4 Approval of the 2011 Moab City Holiday Schedule
5‐5 Approval of an Amendment to the 2010 Moab City Holiday Schedule
5‐6 Approval of the 2011 Moab City Regular Council Meeting Schedule
5‐7 Approval of a Moved‐on Structure for Mark Zink, Located at 311 South Main
Street to Conduct a display on April 19, 2011
SECTION 6: READING OF CORRESPONDENCE
SECTION 7: ADMINISTRATIVE REPORTS
SECTION 8: REPORT ON CITY/COUNTY COOPERATION
SECTION 9: MAYOR AND COUNCIL REPORTS
SECTION 10: APPROVAL OF BILLS AGAINST THE CITY OF MOAB
SECTION 11: ADJOURNMENT
In compliance with the Americans with Disabilities Act, individuals needing special accommodations during this meeting
should notify the Recorder’s Office at 217 East Center Street, Moab, Utah 84532; or phone (435) 259‐5121 at least three
(3) working days prior to the meeting. Check our website for updates at: www.moabcity.org
Page 6 of 135
July 21, 2010
Moab Wastewater Facilities
Planning Review
Moab WWTP Overview
Page 7 of 135
Moab WWTP Overview
• Seasonal loading characteristics result in occasional
permit violations.
• Biological process is overloaded.
• Existing discharge point in Colorado River gives
flexibility due to minimal potential for pollution
indicators.
Increased Regulatory Interest
• Statewide Nutrient Standards Review
• Increasing pressure due to occasional permit
violations.
• Changes in state regulations.
• Increased oversight from EPA.
• State increasing inspection of WWTPs, Collection
Systems, and Pretreatment Plans.
• Moab needs to plan responses, leading to Master
Plan effort.
Page 8 of 135
Design Condition vs. Current Loading
Criteria 1996 Design
Condition
Current
Condition
(2007-2009)
Average Daily Flow, MGD 1.5 0.96
Peak Daily Flow, MGD 1.28
Peak Hourly Flow, MGD 3.1 2.97
Minimum Hourly Flow, MGD 0.15 0.43
Average BOD Load, lb/day 2450 2050
Peak BOD Load, lb/day 3300 4300
Average BOD Concentration, mg/L 196 255
Average TSS Load, lb/day 2600 2010
Peak TSS Load, lb/day 3300 5400
Average TSS Concentration, mg/L 208 249
Flow Trends for Moab WWTP
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Loading Trends for Moab WWTP
Per Capita Loading Conditions
Page 10 of 135
Loading Projections
Design Criteria for 2030
Criteria Value
Average Daily Flow 1.30 MGD
Peak Daily Flow 1.67 MGD
Peak Hourly Flow 3.20 MGD
Minimum Hourly Flow 0.60 MGD
Average BOD Load 2,720 lbs/day
Average BOD Concentration 256 mg/L
Average TSS Load 2,484 lbs/day
Average TSS Concentration 234 mg/L
Page 11 of 135
Moab WWTP
Influent
Pump Station
Headworks
(Screens/Grit
)
Primary
Clarifiers
Trickling
Filters
Secondary
Clarifiers /
Disinfection
Primary
Anaerobic
Digester
Secondary
Anaerobic
Digester
Sludge
Drying Beds
Septage
Receiving
Influent Pump Station
Description
• (2) Archimedes Screw Pumps,
2150 gpm (3.1 MGD) capacity
Deficiencies
• 2030 peak hourly flow is
slightly higher than single
pump capacity.
Recommendations
• Should add pump in
approximately 2025.
Page 12 of 135
Headworks
Description
• (1) Automatic Bar Screen – 1”
• (1) Manual Bar Screen – ½”
• (1) Vortex Grit Trap – 8.5’Ø
• (1) Screenings Compactor
• (1) Grit Classifier
• (1) Comminutor (Grinder)
Deficiencies
• Screening arrangement is not
optimal.
Headworks (cont.)
Deficiencies (cont.)
• State screening and grit
requirements now recommend
two screens and grit.
• Screen prone to icing.
• Comminutor not
recommended for this facility.
Recommendations
• Replace existing automatic
screen and manual screen
with (2) new automatic
screens.
Page 13 of 135
Headworks (cont.)
Recommendations (cont)
• Replace existing automatic
screen and manual screen
with (2) new automatic
screens.
• Enclose or heat trace screens.
• Add a third channel for screen
bypass with manual screen.
• No changes to grit system.
• Eliminate comminutor.
Primary Clarifiers
Description
• (2) 40’Ø Plow-type clarifiers
Deficiencies
• Clarifier No. 1 is quite old and
depth is more shallow than
state recommendation.
Recommendations
• No changes recommended
(collection efficiency is
excellent, units well
maintained).
Page 14 of 135
Trickling Filters
Description
• (1) 72’Ø, (1) 80’Ø Rock
MediaTrickling Filters with
Motorized distributors
mechanisms
Deficiencies
• Biological process capacity is
routinely exceeded.
• Cold and transitional weather
reduces effectiveness.
• Little nutrient removal.
Trickling Filters (cont.)
Alternatives for Review:
• New or expanded biological
process required.
• Previous consideration
provided to covering trickling
filters, oxidation ditches,
RBCs, hybrid systems,
conventional activated sludge.
• Process selected will also
impact solids handling
facilities.
• Energy efficiency and footprint.
Page 15 of 135
Trickling Filters (cont.)
Recommendations
• Supplement existing process
with (2) 20’x100’ aeration
basins (Trickling Filter/Solids
Contact Process).
• Continue using trickling filters
with aeration basins unless
State of Utah implements
nitrogen removal standards.BLOWERSSecondary Clarifiers
Description
• (2) 40’Ø Plow-type clarifiers
• Chlorination occurs in
secondary clarifiers using gas
chlorinator.
Deficiencies
• Both clarifiers have difficulty
with settling solids.
• State of Utah recommends
separate disinfection facilities.
• Chlorine gas presents safety
concerns.
Page 16 of 135
Secondary Clarifiers (cont.)
Deficiencies (cont.)
• Secondary sludge is routed to
headworks.
Recommendations
• Addition of (1) 60’ diameter
spirally raked secondary
clarifier.
• Send sludge to digester.
• Addition of chlorine contact
chamber.
• Inclusion of on-site hypochlorite
generator in design.
Solids Handling Facilities
Description
• (1) 45’Ø Primary Digester with
floating lid and turbine mixer.
• (1) 33’Ø Secondary Digester
with fixed lid (sludge storage)
• (8) Drying beds, various sizes
• Solids disposal at landfill.
Deficiencies
• Insufficient drying bed capacity
for current loads and for future
treatment levels.
Page 17 of 135
Solids Handling Facilities (cont.)
Deficiencies (cont.)
• Digesters have structural
issues.
• Drying beds have structural
problems.
Recommendations
• Refurbishment of digesters
(cover and mixer replacement)
• Mechanical dewatering facility.
• Repair newest beds, demolish
oldest beds.
Moab WWTP - Expanded
BLOWERSPage 18 of 135
Cost of Improvements
Improvement Timeline for Completion Cost of Construction
Influent Pump Station 2025 $150,000
Screening Improvements 2012 $300,000
Aeration Basins / Blowers 2013 $2,500,000
Secondary Clarifier 2013 $650,000
Disinfection Basin 2012 $250,000
Dewatering Facility 2012 $2,500,000
Digester Refurbishments 2015 $500,000
Total:$6,850,000
Potential Regulations – Nutrient Removal
• State currently studying implementation of new
nutrient standards, with 4 scenarios:
• Future design must include contingency to meet
potential new regulations.
Tier Total Phosphorus, mg/L Total Nitrogen, mg/L
1N 0.1 10
1 0.1 No limit
2N 1.0 20
2 1.0 No limit
3 Base condition Base condition
Page 19 of 135
Moab WWTP – Nutrient Removal
BLOWERSSecondary
Clarifier Dewatering / Admin / Hypo(6) 20’x100’
BNR Aeration
Basins
Filtration
Nature Conservancy Project
Page 20 of 135
Nature Conservancy Project
• Beneficial reuse of WWTP effluent.
• Hydraulic concerns appear to be resolved.
• Regulatory concerns:
– Existing permit – Colorado River receiving body
– With diversion – State may interpret wetland as receiving
body.
– State of Utah has not resolved how they will regulate
these types of projects.
Page 21 of 135
City of Moab
Wastewater Facilities Master Plan
DRAFT
October 2010
Prepared for:
The City of Moab
by:
MWH Americas
10619 So. Jordan Gateway
Suite 100
South Jordan, Utah 84095
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Moab Wastewater Master Plan ‐ DRAFT i | Page
TABLE OF CONTENTS
A. Introduction ......................................................................... 1
B. Existing and Future Conditions............................................. 2
1. Project Need and Planning Area Identification ......................................................................... 2
a. Project Need ......................................................................................................................... 2
b. Planning Area ........................................................................................................................ 2
2. Existing Environment of the Planning Area ............................................................................ 13
a. Water Quality Management (WQM) Plans ......................................................................... 13
b. State Priority System and Project Priority List .................................................................... 13
c. Biennial Water Quality Report (305(b)) .............................................................................. 13
3. Existing Wastewater Flows and Treatment Systems .............................................................. 13
a. Influent Pump Station ......................................................................................................... 16
b. Headworks .......................................................................................................................... 16
c. Primary Treatment .............................................................................................................. 16
d. Trickling Filters .................................................................................................................... 18
e. Final Clarifiers ...................................................................................................................... 18
f. Disinfection ......................................................................................................................... 19
g. Biosolids Management........................................................................................................ 20
h. Septage Receiving ............................................................................................................... 20
4. Effluent Limitations ................................................................................................................. 21
5. Infiltration and Inflow ............................................................................................................. 21
6. Future Condition ..................................................................................................................... 24
a. Population and Land Use Projections ................................................................................. 24
b. Forecasts of Flows and Wasteload ...................................................................................... 24
c. Flow Reduction ................................................................................................................... 28
d. Wasteload Analysis ............................................................................................................. 28
C. Environmental Review ....................................................... 29
1. Environmental Information .................................................................................................... 29
2. Historical and Archaeological Sites ......................................................................................... 29
3. Floodplains and Wetlands ....................................................................................................... 29
4. Agricultural Lands ................................................................................................................... 31
5. Wild and Scenic Rivers ............................................................................................................ 31
6. Fish and Wildlife Protection .................................................................................................... 31
7. Air Quality ............................................................................................................................... 31
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Moab Wastewater Master Plan ‐ DRAFT ii | Page
8. Water Quality and Quantity .................................................................................................... 31
9. Direct and Indirect Impacts ..................................................................................................... 31
10. Mitigating Adverse Impacts .................................................................................................... 32
D. Development and Screening of Alternatives ..................... 33
1. Development of Alternatives .................................................................................................. 33
2. Optimum Operation of Existing Facilities ............................................................................... 33
3. Regionalization ........................................................................................................................ 34
4. Unsewered Areas .................................................................................................................... 35
5. Conventional Collection System ............................................................................................. 35
6. Alternative Conveyance Systems ............................................................................................ 35
7. Evaluation of Sewer Alignments ............................................................................................. 35
8. Wastewater Management Techniques ................................................................................... 35
a. Conventional Technologies ................................................................................................. 35
b. Innovative Technologies ..................................................................................................... 35
c. Staged Construction ............................................................................................................ 36
d. Multiple Purpose Projects ................................................................................................... 36
E. Evaluation of Principal Alternatives and Plan Adoption .... 37
1. Alternative Evaluation ............................................................................................................. 37
2. Evaluation of Monetary Costs ................................................................................................. 37
a. Sunk Costs ........................................................................................................................... 37
b. Allocation of Costs for Multiple Purpose Projects .............................................................. 37
3. Reserve Capacity ..................................................................................................................... 37
4. Demonstration of Financial Capability .................................................................................... 37
5. Capital Financing Plan ............................................................................................................. 38
6. Environmental Evaluation ....................................................................................................... 38
7. Evaluation of Reliability .......................................................................................................... 38
8. Evaluation of Energy Requirements ........................................................................................ 38
9. Evaluation of Implementability ............................................................................................... 38
10. Evaluation of Recreational Opportunities ............................................................................... 39
11. Comparison of Alternatives .................................................................................................... 39
a. Two‐Stage Trickling Filters .................................................................................................. 39
b. Oxidation Ditch ................................................................................................................... 40
c. Conventional Activated Sludge ........................................................................................... 41
d. Trickling Filter / Solids Contact ........................................................................................... 42
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Moab Wastewater Master Plan ‐ DRAFT iii | Page
e. Alternatives analysis and scoring ........................................................................................ 43
12. Views of the Public and Concerned Interest Groups .............................................................. 44
F. Selected Plan, Description and Implementation
Arrangements ....................................................................... 45
1. Justification and Description of Selected Plan ........................................................................ 45
2. Design of Selected Plan ........................................................................................................... 45
3. Cost Estimates for the Selected Plan ...................................................................................... 46
4. Energy Requirements of the Selected Plan ............................................................................. 47
5. Environmental Impacts of Selected Plan ................................................................................ 48
6. Arrangements for Implementation ......................................................................................... 48
a. Intermunicipal Service Agreements .................................................................................... 48
b. Civil Rights Compliance ....................................................................................................... 48
c. Operation and Maintenance Requirements ....................................................................... 48
d. Pre‐Treatment Program ...................................................................................................... 49
7. Land Acquisition ...................................................................................................................... 49
TABLE OF FIGURES
Figure 1. Moab‐Spanish Valley & Southeastern Utah. .......................................................................... 3
Figure 2. Planning Area. ......................................................................................................................... 4
Figure 3. Planning Area. .......................................................................................................................... 5
Figure 4. Groundwater quality classification map. ............................................................................... 10
Figure 5. City of Moab zoning and land use plan. ............................................................................... 11
Figure 6. Grand County zoning and land use plan. .............................................................................. 12
Figure 7. Current Moab WWTP flow schematic. ................................................................................. 14
Figure 8. Flow trends. ........................................................................................................................... 15
Figure 9. Biological and solids loading trends. ..................................................................................... 15
Figure 10. Primary clarifier removal efficiency for various flow rates. ................................................ 17
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Moab Wastewater Master Plan ‐ DRAFT iv | Page
Figure 11. Trickling filter BOD and TSS removal efficiency. ................................................................. 18
Figure 12. Secondary clarifier removal efficiency. .............................................................................. 19
Figure 13. Flow versus precipitation. .................................................................................................. 22
Figure 14. Flow for days following precipitation events. .................................................................... 23
Figure 15. Flow versus population for Moab....................................................................................... 25
Figure 16. Flow versus population for Grand County. ......................................................................... 26
Figure 17. Per Capita and Average BOD and TSS loading for Grand County. ...................................... 27
Figure 18. 100‐year flood plain. ........................................................................................................... 30
Figure 19. Two‐stage trickling filter flow schematic. ........................................................................... 40
Figure 20. Oxidation ditch flow schematic. ........................................................................................ 41
Figure 21. Conventional activated sludge flow schematic. ................................................................. 42
Figure 22. Trickling filter / Solids contact flow schematic. .................................................................. 43
Figure 23. New facility components. .................................................................................................... 46
Figure 24. Biological nutrient removal configuration. ......................................................................... 47
Page 26 of 135
Moab Wastewater Master Plan ‐ DRAFT 1 | Page
A. INTRODUCTION
The Moab Wastewater Treatment Plant was last upgraded in 1996. Subsequent to these
upgrades, population growth and increases in tourism within the service area have caused the
wastewater treatment facility to occasionally exceed permit discharge limits. While the
cause of these exceedences has been attributed to seasonal fluctuation in flow characteristics,
wastewater strength, and biological process efficiency, Moab City has elected to update the
Wastewater Facilities Master to determine path forward as the facilities approach their design
capacities and to ensure future compliance with discharge permits.
This Master Plan is intended to provide a way forward for the City to meet the current
discharge permit requirements. Additionally, this plan evaluates the costs of the required
facilities and also presents a plan to comply with potential future regulations concerning
nutrient discharges from the facility, since the State of Utah is currently contemplating
additional standards for all facilities.
Page 27 of 135
Moab Wastewater Master Plan ‐ DRAFT 2 | Page
B. EXISTING AND FUTURE CONDITIONS
1. Project Need and Planning Area Identification
a. Project Need
Population growth and increases in transient population from tourism in the area
serviced by Moab Wastewater Treatment Plant has resulted in increased
biological loading to the facility. The increased loading exceeds the facility’s
capacity to effectively treat influent wastewater to continuously meet the
standards required by the State of Utah. Upgrades to the biological processes are
necessary to ensure full compliance with the requirements of the facility’s
discharge permit.
Additionally, the plant was originally constructed in the 1950s. Portions of the
facility have exceeded the original design life and continue to operate effectively.
However, other components at the facility require renovation or replacement in
order for the facility to provide continued reliable service.
b. Planning Area
Spanish Valley is located in Grand and San Juan Counties of Southeastern Utah
as shown in Figure 1. The planning area consists specifically of the City of Moab
and the Grand Water & Sewer Service Agency, the boundaries of which are
shown in Figure 2 and Figure 3. The planning area outlined by the 208 plan only
includes that part of Spanish Valley that is in Grand County. However, it is
expected that future growth in Spanish Valley within San Juan County will also
impact the wastewater facilities, leading to the inclusion of these areas in the
facilities master plan. The planning area is located in the middle of the
Canyonlands Section of Utah and as a result receives a large number of tourists
and vacationers during the spring, summer, and fall months.
Climate
The climate of the area is characterized by hot, dry summers and cold winters.
The annual average precipitation as recorded at Moab is 7.94 inches. July and
January are generally the driest months of the year, with most precipitation falling
in October. The mean annual temperature for the Moab area is 56°, with the
highest monthly mean occurring in July at 81°. The lowest monthly mean is 30°,
which occurs in January. The frost free period for the Planning Area is about 184
days. The average monthly temperature and precipitation data are summarized
on Table 1.
Page 28 of 135
Moab Wastewater Master Plan ‐ DRAFT 3 | Page
Figure 1. Moab-Spanish Valley & Southeastern Utah.
Page 29 of 135
Moab Wastewater Master Plan ‐ DRAFT 4 | Page Figure 2. Planning Area. Page 30 of 135
Moab Wastewater Master Plan ‐ DRAFT 5 | Page Figure 3. Planning Area.Page 31 of 135
Moab Wastewater Master Plan ‐ DRAFT 6 | Page
Table 1. Moab average annual precipitation and temperature (Source: Moab General Plan, 2002)
Average Daytime/Nighttime Monthly
Temperatures (Fahrenheit)
Precipitation
(inches)
JAN 49.6/18.0 .53
FEB 50.4/25.5 .62
MAR 60.2/34.2 .71
APR 72.5/41.9 .79
MAY 82.4/50.1 .57
JUNE 92.0/57.5 .45
JULY 99.0/64.1 .49
AUG 95.3/62.8 .87
SEPT 87.1/52.8 .83
OCT 73.8/40.8 1.16
NOV 56.0/30.6 .60
DEC 45.1/21.4 .64
Organizational Context
The City of Moab has the responsibility for collection and treatment of its
wastewater. The governing body of the City is made up of a Mayor and five City
Councilmen. The City employs a City Manager who supervises staff and
implements policy as directed by the Council. The Public Works Director, who
oversees both water and wastewater reports to the City Manager and also
supervises the Water and Sewer Superintendent, who in turn supervises the
Wastewater Treatment Plant Operator and the Water and Sewer Service Workers.
The City collects and levies service fees for wastewater collection and establishes
use ordinances. Moab City also treats sewage from the Grand Water & Sewer
Service Agency in accordance with a contract between the City and the Agency.
Demographics
Grand County has a total population of approximately 9,500 as estimated in July
2009. Moab, the county seat, is the largest city in the area with a population of
about 5,100. The City of Moab, therefore, makes up approximately 54% of the
population of Grand County. The population of Spanish Valley in no longer
tallied separately, but from 1960-1980 made up between 20 and 23% of the
population of Grand County. The only other community in Grand County
separately counted by the US Bureau of Census is Castle Valley, which currently
has a population of about 390 residents. The population history for Grand
County and Moab is shown in Table 2.
Page 32 of 135
Moab Wastewater Master Plan ‐ DRAFT 7 | Page
Table 2. Grand County Population History. Source: US Bureau of Census, Census of Population, 1890-2000.
Utah: Utah Population Estimates by County, 2001-2009.
Year Grand County
Population
City of Moab
Population
Moab % of
County
1890 541
19 1149 376 33% 00
1910 1595 586 37%
19 1808 856 47% 20
1930 1813 863 48%
19 2070 52% 40 1,084
1950 1903 1,274 67%
19 6345 74% 60 4,682
1970 6688 4,793 72%
19 8241 65% 80 5,333
1990 6620 3,971 60%
20 8485 56% 00 4,779
2001 8,423 4,821 57%
2002 8,468 4,904 58%
2003 8,464 4,921 58%
2004 8,611 4,893 57%
2005 8,826 4,958 56%
2006 9,024 5,018 56%
2007 9,125 5,085 56%
2008 9,326 5,121 55%
2009 9,493
The population history for Moab and Grand County shows sporadic growth. In
the decade 1950 to 1960 the population of the county more than tripled as a result
of uranium mining and processing activity in the area. The boom of activity
subsided and in 1965 the population began a decline which lasted until 1973. In
1974 interest was
in the area, however in the 1980s, the
renewed in the energy and many other natural resources found
uranium industry once again declined,
%.
The Spanish Valley of Southeastern Utah resembles a structural trough but its
origin and configuration are more complex. The Valley is approximately 13
miles long and 1 ½ miles wide and lies along a northwesterly axis. The lowest
leading to major population declines which did not stop until 1990.
Growth in the 1990s and 2000s has largely been the result of increases in the
tourism and recreation industries. However, this growth has been much slower
and more consistent than previous cycles, with per annum increases of about 2
The tourism and recreation traffic is seasonal, which causes considerable
variability in the overall population of the town throughout the year, with peak
visitation occurring during the weeks surrounding the Easter holiday.
Topography and Geology
Page 33 of 135
Moab Wastewater Master Plan ‐ DRAFT 8 | Page
Valley. The Valley is bounded on the east by
the l Mou ve vatio feet at Mount
M in. T nde ide b usive stocks of
ter ge and y hogs stone fo . A more
co discussion e geology of th surrounding area is described by Baker
(1933), Hunt (1958), and Richmond (1
Sp Valley itse ade up of qua ry deposits ra in thickness from
0 feet. The a thickness of lluvial and e eposits in Spanish
Valley is estimated to be 70 feet. This principal groundwater source for
m the irrigati smaller dom ells in Spanish Valley. Besides the
un idated dep f the Valley e other main aquifer supplying
do water is th ajo sandston er. The City oab and the Grand
W Sewer Ser gency’s wel extract wate ly from the
Navajo sandstone as well as the quate posits of th y.
The alluvial fill in S cribed as a g sand with a high
hydraulic conducti rom drillers composition of the Valley fill is
es as follow rcent clay, 4 t silt, 50 per nd, 23 percent
fine to medium gra 16 percent gravel. In a of 18 wells in
Sp Valley Sum 1971 of the USGS found the average hydraulic
co vity to be y as shown e 3. From data he compiled for the
entire valley the average hydraulic conductivity was calculated to be
approximately 140 The septic f Spanish Va rain into this
va l aquifer. g groundwa lity classific for the Spanish
Valley is shown in 4.
elevation of approximately 3950 feet is found at the Colorado River in the
extreme northwestern portion of the
La Sa
ellenth
ntains which ha
he Valley is bou
are rimmed b
a maximum ele
d on the west s
acks of sand
n of 12,646
y dioritic intr
rmationstiary a
mplete on th e
962)
anish lf is m terna nging
to 360 verage the a olian d
is the
any of on and estic w
consol osits o floor th
mestic e Nav e aquif of M
ater &vice A ls both r large
rnary de e Valle
panish Valley can be des ravelly
vity. F logs the
timated s: 7 pe percen cent sa
vel, and course study
anish sion (
nducti 80 ft/da in Tabl
ft/day.tanks o lley d
lley fil Existin ter qua ations
Figure
Page 34 of 135
Moab Wastewater Master Plan ‐ DRAFT 9 | Page
Table 3. Aquifer Characteristics of the Valley Fill (Sumison, 1971)
Well number
Specific capacity
(gpm/ft of
drawdown)
Transmissivity
(cubic ft per
day per ft)
Saturated
thickness
(ft)
Hydraulic
conductivity
(cubic ft per day
per square ft)
(D-25-21) 36cda-l 41 8,000 225 36
(D-26-22) 6cbb-l 36 7,000 140 49
6cbb-2 20 3,700 125 29
7bac-l 25 4,300 125 35
8cba-l 20 3,700 40 94
8dcb-l 30 5,700 50 115
16cdd-l 36 7,000 65 107
17aac-l 48 8,700 50 174
17aad-l 18 3,100 70 44
17ada-2 10 1,600 50 32
17cab-l 20 3,700 50 75
20acd-l 20 3,700 30 124
21bdd-l 20 3,600 50 72
22cbb-l 32 5,700 75 76
22cbd-l 60 11,600 100 116
22dcb-l 90 13,900 105 132
35abd-l 30 4,700 120 39
35bdd-2 30 5,700 160 36
Averages (rounded) 30 6,000 90 80
LandUse Patterns
Land-use in Grand County is dictated by a number of limiting factors. There are a
total of 2,362,880 acres within Grand County. 79.7% of the land area is owned
by the Federal Government and an additional 15.69% is owned by the State of
Utah. Only 4.6% is private land and 0.01% is owned by the cities and county.
The existing land usage for Moab and Spanish Valley are given in Figure 5
and Figure 6.
Page 35 of 135
Moab Wastewater Master Plan ‐ DRAFT 10 | Page Figure 4. Groundwater quality classification map.Page 36 of 135
Moab Wastewater Master Plan ‐ DRAFT 11 | Page
Figure 5. City of Moab zoning and land use plan.
Page 37 of 135
Moab Wastewater Master Plan ‐ DRAFT 12 | Page
Figure 6. Grand County zoning and land use plan.
Page 38 of 135
Moab Wastewater Master Plan ‐ DRAFT 13 | Page
2. Existing Environment of the Planning Area
a. Water Quality Management (WQM) Plans
The Moab WWTP is a key component of the 208 plan for the area. It acts as a
regional treatment facility for the whole of Spanish Valley and provides a benefit
to the quality of the Colorado River. The City and County also have water quality
management plans in place to prevent contamination to the local watershed.
These plans include stormwater prevention planning requirements, pretreatment
programs for industrial and commercial dischargers, and careful monitoring and
maintenance of collection systems.
b. State Priority System and Project Priority List
The Moab Wastewater Treatment Plant is not currently featured on the State
Priority System or Project Priority List. One reason for completion of the
wastewater master plan is to provide information that would enable the State to
include the wastewater facility on the Project Priority List, making the facility
eligible for financial assistance from the State.
c. Biennial Water Quality Report (305(b))
The Colorado River has been given beneficial use classifications of 1C, 2B, 3B,
and 4 at the point of discharge and is noted as supporting all beneficial uses in the
Biennial Water Quality Report (305(b)). However, this segment of the river is
classified as “needing a TMDL” both above and below the City of Moab due to
selenium contamination from sources located outside of the borders of the State of
Utah. The report indicates that no contamination within the river is of municipal
point source origins.
3. Existing Wastewater Flows and Treatment Systems
The Moab WWTP was initially constructed for primary treatment and was
econdary treatment in 1967. Additional expansion
has been completed several times throughout the life of the plant, with the latest
expansion completed in 1996, which included new headworks facilities, addition of
both a primary and secondary clarifier, installation of a new septage dump station,
and several other improvements to increase the plant’s reliability and operability.
The existing facility flow schematic is shown in Figure 7.
subsequently modified to include s
Page 39 of 135
Moab Wastewater Master Plan - DRAFT 14 | Page Figure 7. Current Moab WWTP flow schematic. Changes in plant loading characteristics have led to conditions where the plant occasionally is unable to meet the regulatory limits for wastewater effluent concentrations required by the plant’s discharge permit. While the flow trend to the facility has been nearly flat for the past decade (Figure 8), the biological loading has increased consistently (Figure 9). This suggests that the inception of flow reduction programs by the City of Moab and by Grand Water and Sewer have been effective at reducing water use and the consequent delivery to the wastewater treatment plant. While this reduction in hydraulic loading is beneficial for some portions of the treatment plant, particularly the hydraulic and physical separation processes, the biological processes can become overloaded. There is good evidence that this has occurred at Moab, since the primary clarifier treatment efficiency improves at lower flows, while the trickling filter efficiency improves at higher flows as will be presented below. Page 40 of 135
Moab Wastewater Master Plan ‐ DRAFT 15 | Page
Figure 8. Flo
Figure 9. Biological and solids loading trends.
w trends.
y = 2E‐06x + 0.372
2001 9/1/2002 1/14/2004 5/28/2005 10/10/2006 2/22/2008 7/6/2009 11/18/2010
4
y = 9E‐06x + 1.1778
y = ‐2E‐06x + 3.4961
0
1
2
3
4
5
6
7
8
4/19/Flow, MGDMin Flow/Average
Max Flow / Average
Max/Min
0
1000
2000
3000
4000
5000
6000
Loading (lbs/day)TSS
BOD
Linear (TSS)
Linear (BOD)
Page 41 of 135
Moab Wastewater Master Plan ‐ DRAFT 16 | Page
a. Influent Pump Station
All flow to the Moab WWTP enters the facility through a 24 inch diameter
gravity sewer that feeds the influent pump station. The influent pump station
includes two screw pumps, with room for a third screw pump. The capacity of
each screw pump is approximately 2150 gpm, which means the influent pump
station has a total capacity of 3.1 MGD peak flow with a single pump operating.
This influent pump station capacity is adequate for current flows. Future flows
will require the addition of another screw pump. The total capacity of the influent
pump station with the addition of third screw pump of equal capacity and
configuration to the existing screw pumps is 4,300 gpm, or 6.2 MGD at peak
flow, which will be sufficient for the duration of the 20 year planning period.
However, the third pump will be required in approximately the year 2025, as
dictated by the threshold peak hourly flow of 2150 gpm being reached.
b. Headworks
The Moab WWTP headworks features a ¾” automatically raked bar screen
followed by a ½” manual bar screen, comminutor, and induced vortex grit
chamber. The screens were designed for a capacity of 4.5 MGD, while the grit
system was designed for a capacity of 4.2 MGD.
creening design configuration results in challenges for the operators, since
the manual screen’s smaller aperture size in relation to the automatic screen
results in a frequent need for manual raking. Additionally, the outdoor
installation of all headworks equipment results in ice dams building up on the
automatic screen in freezing weather, which results in either collection of water
with the screenings or alarm conditions in the screen as it reaches a high head
condition due to plugging. Grit collection is generally acceptable.
Screenings and grit handling equipment is located in an indoor facility.
Screenings are compacted and dried using a screw compactor, while grit is
dewatered using a screw classifier. Collected solids are disposed of in the local
municipal landfill.
The current headworks configuration does not meet current State of Utah design
guidelines. Current guidelines for a plant the size of Moab’s call for mechanically
cleaned screens to have a bar spacing of less than 5/8 of an inch, a minimum of
two screens, and inclusion of two grit systems. Additionally, freeze protection is
required for screens installed outside.
c. Primary Treatment
Primary treatment is achieved through the use of two conventional 40-foot
diameter circular clarifiers. Clarifier No. 1 was part of the original primary
ide water depth of 7-feet, while clarifier no. 2 was
constructed in 1996 and has a side water depth of 8-feet. Using the Utah State
standard for plants treating greater than 1 MGD, the clarifiers would be permitted
The s
treatment plant and has a s
Page 42 of 135
Moab Wastewater Master Plan ‐ DRAFT 17 | Page
ns per day per square foot, and a 1256 square feet per
lts.
e
e.
y
e
e
r
performance is possible without additional testing. However, the excellent
indicate that it is likely that the clarifiers will still perform
igh
Figure 10. Prima
a loading rate of 1,000 gallo
clarifier would be rated for a flow of 1.26 MGD.
Both clarifiers are performing very well, with better than expected settling resu
Using the State’s standard sizing rate of 1,000 gallons per day per square foot, th
clarifier efficiency would be approximately 31.5% at the 1.26 MGD rating abov
Using the actual loading rates, predicted performance is about 37.8% (using an
average flow of 0.93 MGD for the plant, split between two clarifiers for a flow
per clarifier of 0.465 MGD and loading rate of 370 gpd per square foot).
However, performance data collected for the clarifiers since 2008 has shown an
average removal efficiency of 63% for BOD and 69% for TSS with an average
daily flow of 0.93 MGD. Figure 10 shows the performance data for the primar
clarifiers at the tested flow rates. Linear regression of the data indicates that th
data is scattered with no clear trends to permit prediction of clarifiers above th
flows encountered during testing, meaning no clear prediction of clarifie
settling results
adequately above the current rated 1.25 MGD. This is likely a result of the h
solids and BOD loading that the plant currently receives.
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
80.0%
90.0%
100.0%
0 1.20Removal Efficiency Flow (MGD)
0.70 0.80 0.90 1.00 1.1
y = ‐0.1707x + 0.7922
R² = 0.0828
y = 0.1644x + 0.5293
R² = 0.0276
BOD Removal Efficie
Average Daily
ncy
TSS Removal Efficiency
Linear (BOD Removal
Efficiency)
Linear (TSS Removal
Efficiency)
ry clarifier removal efficiency for various flow rates.
Page 43 of 135
Moab Wastewater Master Plan ‐ DRAFT 18 | Page
d.
Figure 11. Trickling filter BOD and TSS removal efficiency.
e. Final Clarifiers
40-foot diameter plow-type
Trickling Filters
Secondary treatment at the wastewater treatment plant is provided by two single
stage trickling filters. The trickling filters are both rock media filters, with
motorized distributor mechanisms that were provided in the 1996 plant expansion
project. Trickling filter number 1 is 72-feet diameter, while trickling filter
number 2 is 80-feet diameter and both filters have a 7-foot media depth.
The trickling filters are biologically overloaded. This is particularly an issue
during the cold winter months when the facility receives its lowest flows. This
results in low efficiency of removal and poor BOD removal during these times.
When the hydraulic loads are increased, the removal efficiency improves, which
typically corresponds to the summer months, when the temperature is warmer
(Figure 11).
y = 0.2934x + 0.3131
R² = 0.2289
y = ‐0.3348x + 0.5684
R² = 0.094
‐20.0%
‐10.0%
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
80.0%
0.70 0.80 0.90 1.00 1.10 1.20Removal EfficiencyAverage Daily Flow (MGD)
BOD Removal Efficiency
TSS Removal Efficiency
Linear (BOD Removal
Efficiency)
Linear (TSS Removal Efficiency)
Final clarification is achieved through the use of two
raked clarifiers.
Page 44 of 135
Moab Wastewater Master Plan ‐ DRAFT 19 | Page
final clarifiers has resulted in some difficulty at times in
e 12).
to
Figure 12. Secondary clarifier removal efficiency.
f. Disinfection
by the addition of gaseous chlorine to
the final clarifiers. Contact time is limited to the retention time available in the
to the poor secondary clarifier performance, it is likely that
the chlorine contact from the clarifiers for many years, as is best
practice.
The small size of the
removing TSS from the wastewater flow. Initially, the clarification area was to be
supplemented by means of tube settlers, but this type of modification has not
proven to be effective for final clarification at the site and is no longer practiced
or proposed for implementation.
These final clarifiers show poor and inconsistent removal efficiency (Figur
BOD removal is typically around 40%, while TSS removal is about 70%.
Removal results do not correlate well with flow, meaning there is no good way
predict the operable efficiency of the clarifiers. Many attempts have been made
through the years to improve the consistency of the clarifier operations without
success.
y = ‐0.0022x + 0.4176
R² = 4E‐06
y = ‐0.036x + 0.7409
R² = 0.0023
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
80.0%
90.0%
0.70 0.80 0.90 1.00 1.10 1.20Removal EfficiencyAverage Daily Flow (MGD)
BOD Removal
Efficiency
TSS Removal
Efficiency
BOD Removal
Efficiency
TSS Removal
Efficiency
Wastewater disinfection is accomplished
final clarifiers. Due
some short circuiting is occurring within the clarifiers, resulting in low contact
times within the clarifiers. Additionally, the State of Utah has recommended that
the plant separate
Page 45 of 135
Moab Wastewater Master Plan ‐ DRAFT 20 | Page
g.
c
adequate at times. While solids dry very fast during hot, dry
summers, if rainfall is higher than normal, it is very difficult to achieve a level of
dryness that is acceptable to the landfill. Additionally, solids dewatering
essentially stops during the cold winter months.
h. Septage Receiving
The city of Moab WWTP also serves as the only septage receiving facility in the
area. Septage is received from homes not connected to the sewer system along
with recreational facilities operated by vendors for the National Park Service.
The total monthly volume of septage received at the Moab WWTP is found
in Table 4.
Table 4. Septage receipt volumes (gallons).
Biosolids Management
Biosolids management at the facility consists of volume reduction by anaerobic
digestion, solar drying, and ultimate disposal by landfilling at the Grand County
Landfill. No beneficial use has been incorporated into the biosolids management
programs for the facility, as the volume of solids is relatively minimal and the
additional costs and regulatory burden have not been found justifiable. Digester
gas is consumed by a digester gas boiler, which is used to heat the anaerobi
digester.
The biggest challenge to biosolids management efforts at the facility is the
management of solids during drying. The volume of the solids drying beds at the
facility is in
2005 2006 2007 2008 2009
January 6017 10602 10036 20039 2746
February 37693 2778 21864 29748 35117
March 12643 26126 36761 43668 52986
April 34904 44225 29916 110882 53444
May 39830 45031 53099 63978 57379
June 52861 63250 46090 67098 28099
July 30047 55696 32939 41617 40029
August 25779 20294 59412 38564 38525
September 51162 31434 37205 38506 45233
October 28192 32776 46486 47119 38688
November 49248 40189 35692 55947 48826
December 6358 17013 42242 14405 N/A
TOTALS 374734 389414 451742 571571 441072
Page 46 of 135
Moab Wastewater Master Plan ‐ DRAFT 21 | Page
y not an issue, but can add significant biological
t
4. Eff
The ischarge permit for the facility allows discharge of water to the
Col
Table 5. Moab W
Septage receiving is generall
demands to the facility if not managed properly. Septage is accumulated in the
septage receiving station and is slowly added to the influent flow of the facility a
the influent pump station. The septage receiving facility was included in the 1996
expansion project and does not appear to have any major deficiencies.
luent Limitations
current d
orado River under the following criteria (Table 5):
WTP NPDES Permit discharge criteria.
Effluent Limitations
Parameter
Maximum Maximum Weekly
Monthly Average
Average
Daily
Minimum
Daily
Maximum
BOD , mg/L 25 35 NA NA 5
BOD
Rem
5 Min. %
oval 85 NA NA NA
TSS, mg/L 25 35 NA NA
TSS al 85 NA NA NA Min. % Remov
E. Coli. No/100 mL 126 158 NA NA
TDS y Intake,
mg/R N NA
, Culinar
L eport A NA
TDS L <40 se NA , Effluent, mg/0 increa NA NA
WE
Biomonitoring
T, Acute
NA NA NA Pass
Oil e, mg/L 10 & Greas NA NA NA
pH, Units NA 9.0 Standard NA 6.5
NA – Not Applicable
In general, these criteria are th iteria used by the State of Utah. However,
Moab has additional crit e es TD res olorado
Riv require
5. Infiltration and Inflow
Inf inflow ha ely in at ab W P. Following
the upgrade in 1996, Moab City im aintenance
and anhole lids, pr a w onally,
e stand
eria to m
ard cr
et with r pect to S as a ult of C
er monitoring ments.
iltration and ve larg been m
plemented a plan to im
imized the Mo
prove sewer m
WT
began to seal m eventing surface w ter inflo s. Additi
Page 47 of 135
Moab Wastewater Master Plan ‐ DRAFT 22 | Page
pro
red
The
a tr
stro d the
population discharging to the facility is much greater during the summer months
Figure 13. F ation.
red to determine the level of correlation
etween precipitation and flow increases. As noted previously, the above correlation
By examining the trends in flow volume following days from precipitation events, we
he average flow is appreciably higher on precipitation
jects have been completed to replace sewer lines that were in poor condition,
ucing infiltration.
se improvements are apparent by analysis of the precipitation data. While there is
end for increased flow in proportion to precipitation amounts, it is difficult to find
ng correlation, since precipitation can happen at any time of the year an
(Figure 13).
y = 0.0891x + 0.9224
0.00
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
0.4 0.6 0.8 1 1.2 1.4 1.6 1.8Flow, MGDPrecipitation,
R² =52
0 0.2
inches
low versus precipit
Further analysis of the flow data is requi
b
does not account for the seasonal fluctuations within the service area resulting from
increased transient population. Therefore a different method of examining the
infiltration must be used.
can determine whether or not t
days, which would indicate inflow. The flow following precipitation events is shown
in Table 6.
Page 48 of 135
Moab Wastewater Master Plan ‐ DRAFT 23 | Page
Table 6. Average flows for days following precipitation events.
Days Since Last
Precipitation
Average Daily
Flow, MGD
Mean Minimum
Flow, MGD
Mean Maximum
Flow, MGD
0 0.93 0.29 1.44
1 0.91 0.32 1.39
2 0.90 0.41 1.37
3 0.91 0.41 1.39
4 0.91 0.41 1.40
5 0.91 0.41 1.41
As shown in Table 6, there is not an appreciable difference between average flow
conditions for days of precipitation and days with no precipitation. This is further
shown in Figure 14, which even indicates a slight trend for higher flows for longer
periods without precipitation, although with very little linear correlation. Both show,
however, that there is no good correlation between precipitation events and flow at
the wastewater treatment plant, which indicates that inflow and infiltration are not
major factors impacting operations at the wastewater facility.
Figure 14. Fl following precipitation events.
ow for days
0
0.5
1
1.5
2
2.5
3
0
Max. Flow
Min. Flow
Total Treated MGD
Flow, MGD10203040506070
Days Since Last Precipitation
Page 49 of 135
Moab Wastewater Master Plan ‐ DRAFT 24 | Page
a ion an Projec
pulation trends fo ervice area indic at continued slo th is likely
the area. The Sta Utah projects population growth for selected cities and
counties through vernor’s Office of Planning & Budget. These
dications for both b and Grand County are found in Tabl
s not anticipated t in the f Very little
s.
erall, as San Juan
County (0.8% annually,
compared to 1.0% annually).
b. Forecasts of Flows and Wasteload
Predicting the future flow and wasteload for the Moab WWTP is difficult due to
the ongoing increases in the strength of the wastewater due to water conservation
measures. However, we can use population estimates for Moab and Grand
County along with flow data (Table 7) to estimate the future flows. Additionally,
we can use population data and wastewater strength data to estimate per capita
wasteloads and use this information to project future wasteloads using the
population projections (Table 8).
Table 7. Moab population trends and growth.
Moab Grand
6. Future Condition
. Populat d Land Use tions
Po r the s ate th w grow
for te of
all the Go
pre Moa e 9.
It i hat land use will change appreciably uture.
private land is available for future development. Anticipated future growth is
expected to be the result of increases in development density. Additionally, both
Moab and Grand County have committed to preserving existing land use pattern
However, in San Juan County projected development could include many
residential units in the future, which could have a significant impact on future
waste load allocations. However, it anticipated that population increases in this
area will be largely in line with growth in Grand County ov
County is expected to grow even more slowly than Grand
Year Population Growth Population Growth Ave Flow
2002 4,904 8468 0.9525
2003 4,921 0.35% 8464 -0.05% 0.897178
2004 4,893 -0.57% 8611 1.74% 0.884687
2005 4,958 1.33% 8826 2.50% 0.900137
2006 5,018 1.21% 9024 2.24% 0.914822
2007 5,085 1.34% 9125 1.12% 0.948192
2008 5,121 0.71% 9326 2.20% 0.937022
2009 9493 1.79% 0.955068
Page 50 of 135
Moab Wastewater Master Plan ‐ DRAFT 25 | Page
Table 8. Per capita BOD and TSS for Grand County
d County BOD, TSS, Year Average of Influent Average of Raw Gran
BOD, lb/day TSS, lb/day Population lb/cap lb/cap
1869 1619 8468 0.221 0.191 2002
2003 1858 1536 8464 0.220 0.182
1685 1697 8611 0.196 2004 0.197
2005 1683 1855 8826 0.191 0.210
1780 1966 9024 0.197 0.218
2032 1899 9125 0.223 0.208
2006
2007
2012 1990 9326 0.216 0.213
2116 2130 9493 0.223 0.224
2008
2009
By using linea
Moab WWTP.
Grand County, since it is not certain which population trend will govern the future wastewater
t Grand County will govern future
wastewater volume growth. The plots of population and flow along with the linear regression
formulae are fo
Figure 15. Flow populati oab.
r regression analysis, it is possible to predict the future flow of wastewater to the
This analysis has been completed using population data for both Moab and
flows, although with the larger sample size, it is likely tha
und in Figure 15 and Figure 16.
y = 2.5823E‐04x ‐3.7732E‐01
R² = 9.1537E‐01
0.88
0.89
0.9
0.91
0.93
0.94
0.95
0.96
4,850 4,900 4,950 5,000 5,050 5,100 5,150MGD
pulation
0.92
Flow, Po
versus on for M
Page 51 of 135
Moab Wastewater Master Plan ‐ DRAFT 26 | Page
Predicting the future flow using linear regression assumes that wastewater will be
generated in volumes similar to the past volumes. If water conservation measures
continue to be effective in the service area, it is likely that the predicted
wastewater volumes will be higher than the actual future wastewater flow
volumes. However, in the interest of being conservative, the higher Moab values
should be used for the facility when developing hydraulic loading criteria.
In a similar manner, it is possible to determine the typical per capita BOD and
TSS loads for the area. Unlike in the flow predictions, Moab data should not be
used alone, since this will result in an inappropriate determination of per capita
BOD and TSS loads, resulting in overestimation of the overall load. Therefore,
only Grand County population comparisons were used to determine the per capita
BOD and TSS loads. The per capita and average BOD and TSS loads are shown
in Figure 17.
The trendlines for Figure 17 indicate that the per capita BOD and TSS loads are
relatively constant. The average annual increase in per capita BOD is less than
0.5%, while the increase in per capita TSS is less about 2%. Using the average
per capita values of 0.23 lb/person for BOD and 0.21 lb/person for TSS, we can
predict the overall BOD and TSS loading to the facility (Table 9). When
we come to a conclusion about the
e facility influent for the planning period. In all cases,
the higher, more conservative values should be used.
y = 6.6840E‐05x + 3.1927
Figure 16. Flow versus population for Grand County.
combined with the predicted population,
overall water quality for th
E‐01
R² = 8.2555E‐01
0.89
0
0.92
0
0
0.95
Flow, MGD0.9
.91
.93
.94
0.88
8400 8600 8800 9000 9200 9400 9600
Population
0.96
Page 52 of 135
Moab Wastewater Master Plan ‐ DRAFT 27 | Page
Figure 17. Per C
Table 9. Project
60
542
y = 0.001x ‐1.785
R² = 0.0319
y = 0.0052x ‐10.139
R² = 0.7686
0.000
0.050
0.100
0.150
0.200
0.250
0.300
0.350
0.400
0.450
0.500
0
500
1000
1500
2000
2500
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 Per Capita Loads, lb/personAverage Influent Loads, lb/dayAverage of Influent BOD, lb/day Average of Raw TSS, lb/day
BOD, lb/cap TSS, lb/cap
Linear (BOD, lb/cap)Linear (TSS, lb/cap)
apita and Average BOD and TSS loading for Grand County.
ed population, flows, and loading.
2000 2006 2010 2020 2030 2040 2050 20
Grand Pop 8,485 9,024 9,693 11,007 11,827 12,559 13,781 15,
94
Proje
Projec
Moab Pop 4,779 4,875 5,237 5,946 6,388 6,783 7,443 8,3
cted BOD Load,
lb/day 1952 2076 2229 2532 2720 2889 3170 3575
ted TSS Load,
lb/day 1782 1895 2036 2311 2484 2637 2894 3264
Projections Grand County 1.36
B 316
0 288 Moab 9
Flow 0.89 0.92 0.97 1.05 1.11 1.16 1.24
OD Conc, mg/L 264 270 276 288 294 299 306
TSS Conc, mg/L 241 246 252 263 268 273 28
Flow 0.86 0.88 0.98 1.16 1.27 1.37 1.54 1.7
B 6 252 246 239
TSS Conc, mg/L 249 258 250 239 234 230 225 219
OD Conc, mg/L 273 282 274 262 25
Page 53 of 135
Moab Wastewater Master Plan ‐ DRAFT 28 | Page
c. Flow Reduction
Flow reduction initiatives in the area serviced by the Moab WWTP have been
effective. The result has been a gradual increase in the strength of the wastewater.
Flow to the facility could be further reduced by additional water conservation
initiatives.
d. Wasteload Analysis
Using the data from Table 9, the predicted flow, BOD, and TSS values that
should be used for design purposes should be 1.3 MGD average daily flow, with
2.0 MGD peak hourly flow (using a 1.5 peaking factor, as is typical for the site),
300 mg/L BOD, and 270 mg/L TSS.
Page 54 of 135
Moab Wastewater Master Plan ‐ DRAFT 29 | Page
C. ENVIRO
1. Environmental Information
s to the Colorado River. It is located in an area adjacent
to wetlands and within a 100-year flood plain.
from
was
tim
low harging at its highest flow.
2. Historical and Archaeological Sites
The State of Utah Historic Preservation office has reviewed the Moab Sewage
Treatment Plant site and has concluded that the site should have “no known effect
upon any potential or listed national register historical, archeological, or cultural
sites.”
3. Floodplains and Wetlands
Moab has a history of flooding. The city is subject to flooding from summer
thunderstorms along Mill and Pack Creeks. Flooding may occur with no precipitation
in the city as, “thunderstorms produce short-duration floods originating on nearby
sandstone cliffs, ‘slick-rock’ damage has been limited to erosion of channels, water
and sediment damages to residential area, and deposition of debris and erosion on
roads.” Some flooding also occurs from spring run-off from the Colorado River in
the marshland north of the city. No damage to the city has occurred from these
floods.
Several studies have been done to identify flood hazards and provide assistance in
alleviating this problem. Currently, there are 70 rock debris and detention basins in
the “slick-rock” area. The city and county have established floodplain or flood-
channel zones which restrict development in these areas. There are several other
proposals under consideration including a dam along the Mill Creek, storm drains,
and other diversionary measures to control flooding. The flood hazard zones for a
100-year flood in Moab and Spanish Valley as established by the National Flood
Insurance Program are shown in Figure 18.
The facility is also located adjacent to wetlands. The Colorado River has established
wetlands all along its banks between the town and the river. The Moab WWTP is
located adjacent to these wetlands.
NMENTAL REVIEW
The Moab WWTP discharge
However, the facility is well protected
surface water intrusion through the use of berms around the site. The treated
tewater is greatly diluted by the flow of the Colorado River which is over 1000
es higher than the flow from the Moab WWTP when the Colorado River is at its
est flow and the Moab WWTP is disc
Page 55 of 135
Moab Wastewater Master Plan ‐ DRAFT 30 | Page Figure 18. 100-year flood plain.Page 56 of 135
Moab Wastewater Master Plan ‐ DRAFT 31 | Page
4. Agricultural Lands
The area serviced by the Moab WWTP still consists of some agricultural lands,
although agricultural land in private ownership is very limited. Agricultural lands
consist largely of range land on BLM property.
5. Wild and Scenic Rivers
The Moab WWTP discharges to the Colorado River which, while not currently
designated as such, could be classified as a wild and scenic river at the discharge
location. The Bureau of Land Management is currently considering Segment 4 of the
Colorado River in the State of Utah which reaches from the confluence of the
Colorado with the Dolores River to Mile 49 near Potash for designation as a Wild and
Scenic River due to its recreation value within this segment.
6. Fish and Wildlife Protection
There are several animals listed on the Federal Endangered Species list which are
found in the area. The American Peregrine Falcon (Falco Peregrinus Anatun) is an
uncommon, permanent resident of Arches National Park. The Bald Eagle (Haliaeetus
Leucocephalus (Lucius)), is a common winter visitor to the area. The Colorado
Squawfish (Ptychocheilus Lucius) and the Humpback Chub (Gila Cypha) are both
found in this part of the Colorado River. The Black-footed Ferret (Mustekla
Nigripes) is thought to be in the area, however no confirmed sightings have been
made in recent years.
7. Air Quality
The Moab area and Spanish Valley are not currently under any special restrictions
with respect to air quality. During the winter the site is susceptible to inversion
conditions, however.
8. Water Quality and Quantity
The Moab WWTP discharges to the Colorado River. At this reach of the river, the
supported uses include 1C (drinking water), 2B (secondary contact recreation), 3B
(warm water game fish), and 4 (agricultural use including irrigation and stock
watering). All classified uses are currently supported.
The highest recorded monthly mean flow value for the Colorado River above Moab
was 55,530 cfs in June of 1917, while the lowest monthly mean flow was 1017 in
August of 1934. The overall median flow from 1913 to 2009 was 7190 cfs.
9. Direct and Indirect Impacts
The wastewater facility currently has some impact on water quality in the Colorado
River, but due to the large volume of dilution these impacts are beyond the current
Page 57 of 135
Moab Wastewater Master Plan ‐ DRAFT 32 | Page
termine. Expansion of the facility will permit additional
owever, which may lead to stresses on wildlife and
10.
fort is intended to identify an alternative that will
leaving the Moab WWTP. This will result in
nticipated to occur in the wetlands and
the Colorado River, bypassing any wetlands.
capability to accurately de
development in the area, h
agricultural lands.
Mitigating Adverse Impacts
The current facility planning ef
improve the quality of effluent
improvements in the quality of water in the Colorado River, although these
improvements will be nearly imperceptible.
Moab City and Grand County are attempting to mitigate the impacts of development
on the environment surrounding the facility. Both entities have adopted General
Plans, outlining plans for preserving agricultural lands while mitigating impacts on
wildlife.
No facility construction is currently a
wastewater is discharged directly into
Page 58 of 135
Moab Wastewater Master Plan ‐ DRAFT 33 | Page
D. DEVE D SCREENING OF ALTERNATIVES
Development of Alternatives
ation and planning techniques into
The criteria used to develop and screen alternative wastewater management plans was
presented in Sections B and C of this report. Principal feasible alternative wastewater
treatment plant processes that have potential for the Moab Treatment Plant were also
defined and discussed in Section C.
From a conceptual standpoint, three fundamental alternatives exist for the study area.
These include:
1. No action.
2. Optimization of operations.
3. Construction of new facilities.
Since the construction of the existing wastewater management facility at Moab,
treatment standards have tightened considerably, and wastewater flow rates and
biological loading rates have increased to nearly match and occasionally exceed the
capacity of the existing treatment plant to effectively treat influent flows. As a result,
continued operation without a plan of action for change will result in discharge permit
violations. It is clear, therefore, that a “no action” plan in the Moab-Spanish Valley
area is unacceptable and was not considered further.
The feasibility of optimizing operations to meet standards is discussed below in a
separate section. However, the general conclusion of the Study is that the existing
facility is presently being operated near its optimum level and is likewise not a viable
alternative. As a result, the remaining portions of this section are all based on
alternatives involving construction of new facilities.
2. Optimum Operation of Existing Facilities
In spite of the excellent operation and maintenance of the Moab Sewage Treatment
Plant, the treatment facility has not been able to meet its NPDES discharge permit.
Review of the initial design calculations show that the treatment facility was designed
to produce an effluent quality that would meet the 25 mg/L BOD5 and TSS
LOPMENT AN
1.
Key components of a facilities plan include development and presentation of
alternative plans. The presentation serves to define factors considered and
approaches taken to combine available inform
feasible alternatives and to establish a foundation for the selection of a recommended
plan. Alternative plans by way of their presentation at public hearings also offer the
public an opportunity to participate in the selection of key features of alternatives
considered and ultimately in the final plan itself.
The objective of this section is the present the principles considered in formulation
and the features of alternative plans.
Page 59 of 135
Moab Wastewater Master Plan ‐ DRAFT 34 | Page
requirement on a 30-day average and 35 mg/L of the same water quality parameters
on a 7-day average at a design flow of 1.5 MGD and BOD and TSS loading rate of
e winter. While
the permit requirements for the facility have remained the same as they were
following the most recent expansion and the hydraulic capacity of the plant has not
ds load to the facility has exceeded the design
ly
y,
Table 10. Su
lb/day
2130 2090
0.96 2050 2010
nt has operated very well, reporting only
n 7-
es in tourism in the area. Due
om
3. Regionalization
tewater treatment facility in
a
3300 lb/day in the summer or 1600 and 1900 lb/day respectively in th
been exceeded, the biological and soli
criteria (Table 10). The peak loads to the facility have often exceeded even these
average criteria, with the all time peak BOD5 load to the facility reaching near
4,300 lbs/day in October, 2009 and a TSS peak reached at 5,400 lbs/day in Januar
2009.
mmary of Moab WWTP Loading Conditions (2007-2009).
Average Flow,
MGD
Average BOD5,
lb/day
Average TSS,
December-
February
0.82 1600 1590
March-May 0.98 2190 2090
June-August 1.05 2280 2260
September-0.98
November
Average
Under these loading conditions, the pla
occasional permit exceedences, and only on the 30-day average values, rather tha
day average values. This is a result of the plant operating in excess of its design
efficiencies with respect to primary sedimentation. Lower efficiency in secondary
treatment is usually the major issue with respect to plant permit violations, which
typically occur in both the spring and fall as a result of general plant loading in
combination with weather conditions that challenge the trickling filters, particularly
during spring, when the Moab WWTP reaches its typical peak hydraulic and
biological loading conditions due to the major increas
to the drawbacks associated with the trickling filter process during the transition fr
cold to warm weather and the timing of Moab’s peak loading conditions, alternative
processes should be included in the design of the wastewater treatment plant to
prevent permit exceedences.
The Moab WWTP is currently the only municipal was
Grand County. Separate facilities have recently been studied for treatment of
wastewater generated in Spanish Valley, however a suitable plan for construction of
separate facility was not developed. In addition, there was strong opposition from the
City of Moab and from the State Department of Environmental Quality to
Page 60 of 135
Moab Wastewater Master Plan ‐ DRAFT 35 | Page
4.
e
le to current sewer access.
5. Conventional Collection System
conv on sy ting
has not been evaluated w in the scope of th aster
6. e Conveyance System
conv e systems have been evaluated as part of the master plan.
conve l system is sti cted to provide uired utility
lanning period.
7. of Sewer Alignments
8.
a.
s
ogies
Innovative technologies are acceptable insofar as the technologies have proven
construction of separate wastewater treatment facilities for Spanish Valley and the
remainder of Grand County, since the Moab Wastewater Treatment Plant is for all
intents and purposes a regional facility with capacity to handle current and future
wastewater loads to the facility with some modifications.
Unsewered Areas
There continue to be areas of Spanish Valley that are unsewered. These homes ar
either slated for future expansion of the sewer system or are in areas that are not
accessib
The existing collection system is a entional collecti stem. The exis
collection system
plan.
ith e wastewater m
Alternativ s
No alternative eyanc
The existing
within the p
ntiona ll expe the req
Evaluation
Sewer alignments have not been evaluated within this master plan. Existing
alignments will continue to be used for future expansion of the system.
Wastewater Management Techniques
Conventional Technologies
The use of conventional technologies is desired for the Moab WWTP. This facility i
crucial to sustaining proper wastewater treatment for the community. The facility
currently uses conventional technologies and it is appropriate that conventional
technologies continue to be used, since the existing infrastructure is in place to handle
this type of construction and expansion.
b. Innovative Technol
application on facilities similar to Moab. Additionally, alternatives that have a high
cost of installation and operation were not considered.
Page 61 of 135
Moab Wastewater Master Plan ‐ DRAFT 36 | Page
c.
ading considerations
ired.
d.
ty plans will need to incorporate projects within
Staged Construction
Facility construction should be staged to permit inclusion of additional facilities as
the demands on the wastewater treatment facility require. Additionally, construction
of some facilities will be dependent upon flow or biological lo
before they will be requ
Multiple Purpose Projects
Facilities should be designed to incorporate multiple uses as far as possible.
However, it is recognized that facili
the existing wastewater facilities.
Page 62 of 135
Moab Wastewater Master Plan ‐ DRAFT 37 | Page
E. EVAL
ADOP
d for the facility. Four principle alternatives for
biological treatment were evaluated for use at the Moab WWTP. These alternatives
include:
1. Two-Stage Trickling Filters
2. Oxidation Ditch
3. Conventional Activated Sludge
4. Trickling Filter / Solids Contact
These alternatives are described further below.
2. Evaluation of Monetary Costs
a. Sunk Costs
All existing improvements have been treated as sunk costs. Preservation of
existing utility has been considered where the existing infrastructure is still
suitable for the purposes of the alternative. Where the infrastructure is not
suitable, it would be abandoned or demolished.
b. Allocation of Costs for Multiple Purpose Projects
The nature of the existing facility is not conducive to multiple purpose projects.
Therefore, the full cost of the facility must be borne by the wastewater treatment
operations.
3. Reserve Capacity
Facilities will allow for redundancy to prevent mechanical failure leading to violation
of permit requirements.
4. Demonstration of Financial Capability
Both Moab City and Grand Water & Sewer have the financial capability of
supporting improvements at the Moab WWTP. Both entities have accumulated
UATION OF PRINCIPAL ALTERNATIVES AND PLAN
TION
1. Alternative Evaluation
Correction of the deficiencies at the Moab WWTP will require examining all of the
process areas at the facility, but choices for every other process unit will depend on
the major treatment process selecte
Page 63 of 135
Moab Wastewater Master Plan ‐ DRAFT 38 | Page
impact fees for the purpose of paying for treatment plant improvements. Grand
Water & Sewer is currently holding $1.2 million for treatment projects, while Moab
is responsible for all financial obligations of the wastewater treatment
City of Moab has demonstrated an ability to balance the facility budget
while maintaining the facilities appropriately. Grand Water & Sewer is for all intents
oab WWTP, paying for treatment services in proportion
tem.
5.
the State of Utah in the form of grants and low-
ding be required, the City will seek to finance the
an increase in the cost of collection and treatment fees likely
provements.
6.
ly different environmental impacts.
All site work will be confined to the existing facility. Therefore, there will be no
e systems with respect to environmental
considerations.
Reliability
Rel ty of
the is
like e
thro r number of mechanical
8. Eva
Energy requirement for the different alternatives include pumping, aeration and
significant differences between these alternatives with
eds. Significant increases in power will result in additional
site to
City also maintains some funds, although with a much smaller balance.
Moab City
plant. The
and purposes a client of the M
to flows from its collection sys
Capital Financing Plan
Financing of any improvements will need to come from multiple sources. The first
source of financing will be the development impact fee reserve funds. Additionally,
the City will seek funding from
interest loans. Should additional fun
facility by bonding, with
required in order to pay the debt associated with facility im
Environmental Evaluation
None of the alternatives will provide significant
evaluation of the differences between th
7. Evaluation of
iability is considered in two ways: the reliability of treatment and the reliabili
susceptibility of mechanical equipment to failure. Treatment process failure
ly to be an issue where processes are sensitive to large swings in temperatur
ughout the annual cycle. Conversely, the greate
components included in the system, the greater likelihood of failure of those
components.
luation of Energy Requirements
mixing costs. There are
respect to the power ne
expenses related to construction of new facilities, since power service to the
wastewater treatment plant will need to be upgraded as well.
9. Evaluation of Implementability
Implementability considerations must include compatibility with the existing
prevent failure of the existing processes during construction activities. Process
Page 64 of 135
Moab Wastewater Master Plan ‐ DRAFT 39 | Page
tion
10.
icipated to be gained by any of the treatment
alternatives.
1. Comparison of Alternatives
d
meter secondary clarifier designed to effectively
nd permit the existing clarifiers to be drained and
• Refurbishment of the primary digester through the replacement of the
and mixer.
a.
tage trickling filter alternative would add a second stage of tricking
filters to the existing trickling filter process. The flow schematic for the process
s to
d
ters have been
employed at the Moab WWTP for decades and are compatible with the existing
ed footprint available on the site for two
alternatives that interfere with existing processes must permit partial implementa
of the new process as an interim measure.
Evaluation of Recreational Opportunities
No recreational opportunities are ant
1
Regardless of the alternative selected, several improvements will be necessary. As
noted previously, headworks, secondary clarification, disinfection, digestion, an
solids dewatering improvements will be required. These improvements will include:
• Replacement of the screen with a new screen designed to effectively remove
debris from the influent without additional operator intervention.
• Addition of a new 60 ft. dia
remove the effluent solids a
maintained.
• Addition of a chlorine contact chamber and conversion from the use of
chlorine gas to an on-site sodium hypochlorite generator.
anaerobic digester cover
• Construction of a new dewatering facility to handle the increase in solids
generated by the facility without the need for additional solids drying beds.
This facility will also include new operator offices.
TwoStage Trickling Filters
The two-s
is shown in Figure 19.
This process has a distinct advantage over the other alternatives when it come
energy consumption. The only additional energy that will be required is the
energy necessary to pump the effluent water from the first stage to meet the hea
requirements of the second stage.
This process is very familiar to the operators. Tricking fil
infrastructure. However, there is limit
new trickling filters. Additionally, it is likely that this process will produce lower
treatment efficiency during low temperatures.
Page 65 of 135
Moab Wastewater Master Plan - DRAFT 40 | Page While it is likely that this process will effectively treat the wastewater, if future nutrient regulations are required the facility will have a difficuly time meeting the regulations. While nitrification will be possible with the two-stage process, trickling filter processes are not able to effectively denitrify. This process will result in reduction of the effluent ammonia concentration, but will do very little to reduce the overall effluent nutrient load. Figure 19. Two -stage trickling filter flow schematic. b. Oxidation Ditch Oxidation ditches are an effective way of reducing BOD and TSS from wastewater and are particularly suitable to small facilities. Aeration and mixing of the oxidation ditch are typically provided by mechanical aerators. The aerators induce flow around the oxidation ditch while also entraining oxygen in the wastewater by agitating the surface of the water. A flow schematic for an oxidation ditch system is shown in Figure 20. Oxidation ditches are generally very reliable, but do suffer from reduced oxygen transfer efficiency during cold weather. This can result in reduced treatment efficiency during these cold weather times. Oxidation ditches are generally quite simple to maintain. The moving parts consist solely of the mechanical aerator assembly. This assembly can come in a variety of configurations, from horizontal, to vertical, to floating configurations. Oxidation ditches are also suitable for conversion to biological nutrient removal processes. Additional basins must be constructed to provide the necessary anaerobic and anoxic treatement zones that would be required for biological phosphorus and nitrogen removal, but this is much simpler for this type of operation. Additionally, many operators have reported an ability to denitrify Page 66 of 135
Moab Wastewater Master Plan - DRAFT 41 | Page through careful operation of the mechanical aerators to provide in-basin anoxic zones. For the Moab WWTP, inclusion of oxidation ditches would require demolition and abandonment of the existing trickling filters. There is not currently enough space at the facility to accommodate concurrent operation of the trickling filter and oxidation ditch process units, which would necessitate land acquisition in order to complete the project. However, an oxidation ditch could eliminate use of the anaerobic digesters, should the City elect to do so. Oxidation ditches facilitate long solids retention times, which means the oxidation ditches can also act as digesters. Figure 20. Oxidation ditch flow schematic. c. Conventional Activated Sludge Conventional activated sludge processes are the most commonly used types of treatment processes. This process typically uses diffusers located at the bottom of an aeration basin to provide oxygen to the wastewater, although surface aerators can be used in this type of system as well. These systems are known to provide effective treatment in all weather conditions. A schematic of a conventional activated sludge process is found in Figure 21. Conventional activated sludge processes would require the most capital expenditure and would also use the most energy of the alternatives considered. The basins required to effectively treat the total load to the facility will also require demolition of the tricking filter process, however, it would be possible to get a portion of the aeration capabilities on line prior to demolition of the trickling filters. Page 67 of 135
Moab Wastewater Master Plan - DRAFT 42 | Page Figure 21. Conventional activated sludge flow schematic. Activated sludge plants are very conducive to conversion for nutrient removal. Typically it is possible to partition off zones of the aeration basin to provide the necessary anaerobic and anoxic zones to permit effective biological nutrient removal. d. Trickling Filter / Solids Contact The trickling filter / solids contact process is a hybrid between the trickling filter process and the activated sludge process. The trickling filter process is able to cost effectively reduce the BOD, while the solids contact process, which is essentially an activated sludge basin, provides reliable treatment of the wastewater for times when the tricking filter is not able to effectively treat the wastewater, such as during inclement weather. A flow schematic of the trickling filter / solids contact process is found in Figure 22. Another noted benefit for the trickling filter /solids contact process is that the solids produced typically settle very efficiently. This can result in improved secondary clarifier performance. There is additional complexity associated with the tricking filter / solids contact process resulting from the employment of both processes. The operator must be able to balance the requirements of each process. Additionally, there are multiple equipment types that will require maintenance. The trickling filter / solids contact process cannot be adapted for biological nutrient removal without the abandonment of the trickling filter process. However, the solids contact basins can be designed in a manner that would make them effective components of an activated sludge system, should biological Page 68 of 135
Moab Wastewater Master Plan - DRAFT 43 | Page nutrient removal be required in the future. Additionally, the solids contact basins could be located on the site without the need for additional property. Figure 22. Trickling filter / Solids contact flow schematic. e. Alternatives analysis and scoring Using simple scoring, the alternatives were rated on a variety of criteria, as noted above and in Table 11. Alternatives were given a score of 1-4 with 4 being the highest rating and 1 the lowest. The alternative with the highest total points was viewed as the best alternative to meet the current facility requirements. Table 11. Alternative comparison and scoring. Alt. 1 (2-Stage Tricking Filter) Alt. 2 (Oxidation Ditch) Alt. 3 (Conventional Activated Sludge) Alt. 4 (Tricking Filter/Solids Contact) Treatment Reliability 1 2 4 3 Future Regulations 1 3 4 3 Expandability 1 2 3 4 Site Constraints 3 2 1 4 Energy Consumption 4 2 1 3 Maintenance 4 3 2 1 Ease of Operation 2 3 4 1 Constructability 1 3 2 4 Cost 3 2 1 4 Total 20 22 22 27 Page 69 of 135
Moab Wastewater Master Plan ‐ DRAFT 44 | Page
12. Views of the Public and Concerned Interest Groups
Public input has not been obtained for this draft plan. Public input will be solicited
prior to finalization of the plan.
Based on the results of the analysis, the tricking filter / solids contact process was
advanced as the selected process alternative.
Page 70 of 135
Moab Wastewater Master Plan ‐ DRAFT 45 | Page
F. SELECT PLEMENTATION
ARRANGEMENTS
1.
act process provides a good transition from the
existing trickling filter treatment process to an activated sludge process. The trickling
filters will provide a cost effective means of significantly reducing BOD, while the
solids contact basins will provide the capability of effectively treating the plant’s
flows during all environmental conditions.
Energy savings through using this process alternative will be significant, since the
blowers for the solids contact basin will be permitted to operate in response to oxygen
demand. When the trickling filters are operating efficiently, very little oxygen input
will be required. Conversely, during cold periods when the trickling filters have
typically not operated well, the solids contact basins will provide adequate aeration to
prevent violations of the plant discharge permit.
Additionally, the trickling filter / solids contact process will permit future
implementation of biological nutrient reduction, should the State require nutrient
removal in the future. By constructing solids contact basins in a manner and
configuration that will permit their use as part of the activated sludge process, the
facility will be ready for adaptation if necessary. Of course, this conversion will
require demolition of the trickling filters, but the solids contact basins will be able to
provide sufficient treatment of wastewater while the additional aeration basins are
under construction.
2. Design of Selected Plan
The selected plan will be completed as part of a conventional design process. It is
imperative that solids dewatering facilities be constructed prior to the commencement
of additional work, since site staging for the solids contact basins is likely to require
demolition of some of the solids dewatering beds, which are already insufficient for
current needs. Therefore, initial designs should include the solids dewatering facility
along with the solids contact basin, new final clarifier, and new chlorine contact
chamber. The layout of the new facility can be found in Figure 23. Additionally,
conversion of the facility to biological nutrient reduction is shown in Figure 24.
Improvements to the screen and digester could be completed as a separate design
process should the City determine that insufficient funding exists to complete the
work at this time. Additionally, the additional influent pump will not be required in
the immediate future and should not be included in short term design plans.
ED PLAN, DESCRIPTION AND IM
Justification and Description of Selected Plan
The Tricking Filter / Solids Cont
Page 71 of 135
Moab Wastewater Master Plan - DRAFT 46 | Page Figure 23. New facility components. 3. Cost Estimates for the Selected Plan The cost of the recommended improvements are found in Table 12. Table 12. Cost for recommended improvements. Improvement Timeline for Completion Cost of Construction Influent Pump Station 2025 $150,000 Screening Improvements 2012 $300,000 Aeration Basins / Blowers 2013 $2,500,000 Secondary Clarifier 2013 $650,000 Disinfection Basin 2012 $250,000 Dewatering Facility 2012 $2,500,000 Digester Refurbishments 2015 $500,000 Total: $6,850,000.00 Dewatering Facility Blower Facility Solids Contact Basins Secondary Clarifier Chlorine Contact Chamber Page 72 of 135
Moab Wastewater Master Plan - DRAFT 47 | Page Figure 24. Biological nutrient removal configuration. 4. Energy Requirements of the Selected Plan The recommended improvements will result in additional energy consumption at the facility. While the new clarifier will result in virtually no additional energy consumption, the dewatering and aeration systems will consume large amounts of energy. The dewatering facility will require the addition of high energy dewatering equipment and pumps. While a number of dewatering alternatives would be available to this facility, screw presses would appear to be the most feasible alternative at this time, due to the volume of sludge anticipated and the need only to pass a paint filter test to permit solids disposal at the municipal landfill. These screw presses will likely feature 15 hp motors for each press, with two presses recommended. The largest energy use at the site will be the blowers for the solids contact basins, however. The air demands for the process will require at most 20 mg of oxygen per liter of reactor per hour, or about 166 lb per million gallons of reactor per hour. For this facility, we would need to supply approximately 0.62 lb oxygen per minute. This will require about 1300 scfm or 26 kW of power. Page 73 of 135
Moab Wastewater Master Plan ‐ DRAFT 48 | Page
5. Environmental Impacts of Selected Plan
The selected plan is likely to have a positive overall environmental impact.
Implementation of the recommended improvements will result in higher effluent
quality, although this will come at the expense of additional electricity consumption.
However, pollution from increases in electricity consumption could be offset through
the purchase of green energy credits, if the City were to elect to pursue such an
alternative.
Additionally, elimination of chlorine gas from the facility will result in better air
quality. Removal of the tankage and piping for chlorine gas will reduce the potential
for a chlorine gas release, reducing the potential toxic impacts of the wastewater
facility.
6. Arrangements for Implementation
a. Intermunicipal Service Agreements
In order for the City of Moab to implement the recommended facility
improvements, additional cooperation from Grand Water & Sewer will be
required. The two entities will have to cooperate on the timing and financing of
future projects in order to ensure that impact fees associated with improvements
required by population growth are adequately utilized and that impact fees are
fairly assessed. Additionally, it would be appropriate for more data sharing to
occur between the two entities in order to ensure that no adverse impacts are
result of operational or infrastructure changes
implemented by the City of Moab or Grand Water & Sewer.
y
c.
e
ditional
l
experienced by either entity as the
b.Civil Rights Compliance
There are no civil rights compliance issues associated with the recommended
alternative, since the facility is to remain in its existing location, which is largel
isolated from any housing units.
Operation and Maintenance Requirements
The recommended alternative will require significantly more operation labor and
maintenance. The increases in operator attention will largely be required as a
result of addition of the solids contact facility with associated blowers and th
dewatering facility. These mechanical components will require ad
maintenance and may also require specialized maintenance requiring additiona
training for the plant operators. Additionally, it may be appropriate to add an
additional operator and implementation of a scheduled preventative maintenance
program to ensure continued reliable and efficient operation of the wastewater
facility.
Page 74 of 135
Moab Wastewater Master Plan ‐ DRAFT 49 | Page
sting pre-
uld
7. isition
d. PreTreatment Program
The recommended alternative will not require alteration of the City’s exi
treatment program. Future significant sources of wastewater to the facility sho
be evaluated with respect to their potential biological impact on the facility,
however.
Land Acqu
No land acquisitions will be required in order to implement the preferred alternative.
All facilities will be constructed on property currently occupied by the wastewater
treatment plant.
Page 75 of 135
August 24, 2010 Page 1 of 3
MOAB CITY COUNCIL
REGULAR MEETING
August 24, 2010
The Moab City Council held its Regular Meeting on the above date in the
Council Chambers of Moab City Offices, located at 217 East Center
Street, Moab, Utah. Mayor David L. Sakrison called the Pre‐Council
Workshop to order at 6:30 PM. In attendance were Councilmembers
Kyle Bailey, Kirstin Peterson, Sarah Bauman, Jeffrey Davis and Gregg
Stucki; City Manager Donna Metzler, City Recorder/Assistant City
Manager Rachel Ellison, Planning Director Jeff Reinhart, Community
Development Director David Olsen and City Engineer Rebecca Andrus.
Mayor Sakrison called the Regular City Council Meeting to order at 7:00
PM and led in the Pledge of Allegiance. Five (5) members of the
audience were present.
There were no minutes to approve.
There were no Citizens to be Heard.
A Community Development Department Update was not given.
Under Engineering Department Update, City Engineer Andrus stated
that paving had begun on the 500 West Project and that striping of 500
West as well as 400 North would be completed as part of the same
project. City Engineer Andrus stated that the Williams Way Repaving
Project was currently out to bid and that she had attended a productive
meeting with the Utah Department of Transportation (UDOT) regarding
the Highway 191 project.
Under Planning Department Update, Planning Director Reinhart stated
that staff was moving ahead with the Haciendas and Portal Vista
projects and that staff had been investigating the claims of Portal Vista
homeowners regarding the status of improvements. Planning Director
Reinhart then stated that there would not be a workshop at the next
City Planning Commission meeting as staff would be attending the
Grand County General Plan Workshop. Planning Director Reinhart then
stated that there would be a joint City/County Council meeting on
August 27, 2010 at 11:00 AM to discuss complete streets. Planning
Director Reinhart then reviewed the next Planning Commission meeting
agenda.
A Police Department Update was not given.
Public Works Department Update was not given.
Mayor Sakrison opened a public hearing on Proposed Ordinance #2010‐
13 – An Ordinance Amending the City of Moab Municipal Code, Section
17.09 and 17.70, by Establishing Standards and Conditions for Approval
of Specific Conditional Uses; and Proposed Ordinance #2010‐15 – An
Ordinance Amending the City of Moab Municipal Code, Section
17.12.030, Non‐conforming Uses and Non‐complying Buildings at 7:15
PM. Planning Director Reinhart gave a staff summary of the proposed
ordinances.
No public comment was received.
Mayor Sakrison closed the public hearing at 7:25 PM.
REGULAR MEETING &
ATTENDANCE
CALL TO ORDER
APPROVAL OF MINUTES
CITIZENS TO BE HEARD
COMMUNITY DEVELOPMENT
UPDATE
ENGINEERING UPDATE
PLANNING UPDATE
POLICE UPDATE
PUBLIC WORKS UPDATE
PUBLIC HEARING OPENED ON
PROPOSED ORDINANCE #2010‐
13
PUBLIC HEARING CLOSED
Page 76 of 135
August 24, 2010 Page 2 of 3
Under Presentations, Finnoula Kofoed of the Utah Municipal Clerks’
Association presented City Recorder/Assistant City Manager Rachel
Ellison with the designation of Master Municipal Clerk as conferred by
the International Institute of Municipal Clerks for fulfilling educational
and professional development requirements.
Councilmember Peterson moved to approve a Staffing Plan for the
Moab Recreation and Aquatic Center. Councilmember Bauman
seconded the motion. The motion carried 4‐1 aye with Councilmember
Davis voting nay.
Councilmember Peterson moved to approve a Job Description for the
Moab Recreation and Aquatic Center Director Position with the addition
of the requirement of a successful background check. Councilmember
Stucki seconded the motion. The motion carried 4‐1 aye with
Councilmember Davis voting nay.
Councilmember Bailey moved to approve Proposed Ordinance #2010‐20
– An Ordinance Amending the City of Moab Official Zoning Map
Contemplating Rezoning a Property Located at 976 West and 400 North
from I‐1 Industrial to R‐4 Residential. Councilmember Bauman seconded
the motion. The motion carried 5‐0 aye.
Councilmember Bailey moved to approve Proposed Resolution #16‐2010
‐ A Resolution Adopting the City of Moab Cafeteria Plan and Summary
Plan Description Documents, Including Dependent Care and Health
Flexible Spending Accounts. Councilmember Peterson seconded the
motion. The motion carried 5‐0 aye.
The Discussion and Presentation Regarding a Proposed South Area
Annexation was cancelled.
There was no Correspondence to be Read.
Under Administrative Report, City Manager Metzler stated that city staff
had been spending a lot of time developing proposals for operations of
the new aquatics center. City Manager Metzler stated that weekly
aquatics center meetings were being conducted and that the project
was on schedule. City Manager Metzler continued that staff had been
working to communicate the City’s expectations regarding the highway
191 project to UDOT as well as coordinating opening issues for the new
school with the Grand School District, and working with the Nature
Conservancy regarding their use of the WWTP effluent. City Manager
Metzler stated that initial Public Works Director interviews had been
conducted and that staff continued to work on the project issues with
Portal Vista and Haciendas subdivisions.
A Report on City/County Cooperation was not given.
Mayor and Council Reports were not given.
Councilmember Stucki moved to pay the bills against the City of Moab in
the amount of $572,165.15. Councilmember Davis seconded the
motion. The motion carried 5‐0 aye by a roll‐call‐vote.
Mayor Sakrison adjourned the meeting at 8:44 PM.
PRESENTATION BY UTAH
MUNICIPAL CLERKS’
ASSOCIATION
STAFFING PLAN FOR THE
MOAB RECREATION AND
AQUATIC CENTER, APPROVED
JOB DESCRIPTION FOR THE
MOAB RECREATION AND
AQUATIC CENTER DIRECTOR
POSITION, APPROVED
PROPOSED ORDINANCE #2010‐
20, APPROVED
PROPOSED RESOLUTION #16‐
2010, APPROVED
DISCUSSION REGARDING
ANNEXATION, CANCELLED
READING OF
CORRESPONDENCE
ADMINISTRATIVE REPORTS
REPORT ON CITY/COUNTY
COOPERATION
MAYOR AND COUNCIL
REPORTS
APPROVAL OF BILLS
ADJOURNMENT
Page 77 of 135
August 24, 2010 Page 3 of 3
APPROVED: ____________________ ATTEST: ____________________
David L. Sakrison Rachel Ellison
Mayor City Recorder/Asst. City Mgr.
Page 78 of 135
September 14, 2010 Page 1 of 3
MOAB CITY COUNCIL
REGULAR MEETING
September 14, 2010
The Moab City Council held its Regular Meeting on the above date in
the Council Chambers of Moab City Offices, located at 217 East Center
Street, Moab, Utah. Mayor David L. Sakrison called the Pre‐Council
Workshop to order at 6:30 PM. In attendance were Councilmembers
Kyle Bailey, Kirstin Peterson, Sarah Bauman, Jeffrey Davis and Gregg
Stucki; City Manager Donna Metzler, City Recorder/Assistant City
Manager Rachel Ellison, Planning Director Jeff Reinhart, Community
Development Director David Olsen, Police Chief Mike Navarre and City
Engineer Rebecca Andrus.
Mayor Sakrison called the Regular City Council Meeting to order at 7:00
PM and Citizen B.D. Howard led in the Pledge of Allegiance. One (1)
member of the audience was present.
There were no minutes to approve.
There were no Citizens to be Heard.
Under Community Development Department Update, Community
Development Director Olsen stated that the Bureau of Land
Management had approved additions to the Pipe Dream Trail.
Under Engineering Department Update, City Engineer Andrus stated
that staff had participated in the 500 West walk‐through the previous
week and that she had attended the Joint Highway Committee Meeting
in Salt Lake City and had submitted a request for funding for the next
phase of the 500 West Project, which had been approved for funding in
2015.
Under Planning Department Update, Planning Director Reinhart stated
that staff had been working on the Portal Vista project and that there
would be a Planning Commission workshop on September 9, 2010.
A Police Department Update was not given.
Public Works Department Update was not given.
Councilmember Bailey moved to approve a Special Event License for
the Moab Century Tour to Conduct a Road Cycling Event on September
17 and 18, 2010 at 1551 North Highway 191. Councilmember Stucki
seconded the motion. The motion carried 5‐0 aye.
Councilmember Stucki moved to approve a Special Business Event
License for Raft for the Cure 2011 to Conduct a Benefit Event on June
24 and 25, 2011. Councilmember Peterson seconded the motion. The
motion carried 5‐0 aye.
Councilmember Peterson moved to approve a Request for Use of
Swanny City Park by Moab Adventure Center to Conduct a Benefit
Event on June 24 and 25, 2011. Councilmember Bailey seconded the
motion. The motion carried 5‐0 aye.
Councilmember Stucki moved to Confirm the Mayoral Appointment of
REGULAR MEETING &
ATTENDANCE
CALL TO ORDER
APPROVAL OF MINUTES
CITIZENS TO BE HEARD
COMMUNITY DEVELOPMENT
UPDATE
ENGINEERING UPDATE
PLANNING UPDATE
POLICE UPDATE
PUBLIC WORKS UPDATE
SPECIAL EVENT LICENSE FOR
THE MOAB CENTURY TOUR,
APPROVED
SPECIAL BUSINESS EVENT
LICENSE FOR RAFT FOR THE
CURE 2011, APPROVED
REQUEST FOR USE OF SWANNY
CITY PARK BY MOAB
ADVENTURE CENTER,
APPROVED
MAYORAL APPOINTMENT OF
Page 79 of 135
September 14, 2010 Page 2 of 3
Jeff Foster as Moab City Public Works Director. Councilmember Davis
seconded the motion. The motion carried 5‐0 aye.
Councilmember Peterson moved to Award the Williams Way Re‐
pavement Project to LeGrand Johnson in the amount of $354,783.
Councilmember Stucki seconded the motion. The motion carried 5‐0
aye by a roll‐call‐vote.
Councilmember Stucki moved to approve the Williams Way Re‐
pavement Project Contract. Councilmember Bauman seconded the
motion. The motion carried 5‐0 aye.
Councilmember Peterson moved to approve Proposed Ordinance
#2010‐15 – An Ordinance Amending the City of Moab Municipal Code,
Section 17.12.030, Non‐conforming Uses and Non‐complying Buildings.
Councilmember Bauman seconded the motion. The motion carried 5‐0
aye.
Councilmember Bauman moved to approve Proposed Ordinance
#2010‐13 – An Ordinance Amending the City of Moab Municipal Code,
Section 17.09 and 17.70, by Establishing Standards and Conditions for
Approval of Specific Conditional Uses. Councilmember Peterson
seconded the motion. The motion carried 5‐0 aye.
Under a Discussion and Presentation Regarding a Proposed South Area
Annexation, Planning Director Reinhart made a presentation.
Discussion followed.
Under Reading of Correspondence, Mayor Sakrison proclaimed
September 9, 2010 as “Ride for Their Lives Day” in the City of Moab, as
well as a proclamation regarding the Smithsonian Exhibition Explores
America’s Musical Roots exhibit at the Dan O’Laurie Canyon Country
Museum. Mayor Sakrison stated that he had received a letter
regarding “Serve Your National Public Lands Day” as well as a 2010
Census Award.
Councilmember Stucki stated that he had received a letter from a local
business owner regarding a Moab City Police Officer.
City Manager Metzler stated that the issue was in process.
Under Administrative Report, City Manager Metzler stated that city
staff had attended a meeting with the Nature Conservancy and had
outlined the requirements for their project. City Manager Metzler
stated that the Nature Conservancy had concurred with all of the
requirements and that changes needed to be made to the City’s
discharge permit as required by the State of Utah. City Manager
Metzler stated that an agreement would be drafted. City Manager
Metzler stated that Nathan Zaag would be making a presentation at
the first meeting in October. City Manager Metzler stated that the
MRAC (Moab Recreation and Aquatic Center) project was on schedule
and that she was participating on the Grand County School District
Financial Oversight Committee and that a lease was being drafted for
the new Dog Park.
JEFF FOSTER AS PUBLIC WORKS
DIRECTOR, CONFIRMED
WILLIAMS WAY RE‐PAVEMENT
PROJECT AWARD, APPROVED
WILLIAMS WAY RE‐PAVEMENT
PROJECT CONTRACT,
APPROVED
PROPOSED ORDINANCE #2010‐
15, APPROVED
PROPOSED ORDINANCE #2010‐
13, APPROVED
DISCUSSION AND
PRESENTATION REGARDING
THE PROPOSED SOUTH AREA
ANNEXATION
READING OF
CORRESPONDENCE
ADMINISTRATIVE REPORTS
Page 80 of 135
September 14, 2010 Page 3 of 3
A Report on City/County Cooperation was not given.
Mayor and Council Reports were not given.
Councilmember Stucki moved to pay the bills against the City of Moab
in the amount of $1,124,354.55. Councilmember Peterson seconded
the motion. The motion carried 5‐0 aye by a roll‐call‐vote.
Councilmember Bailey moved to adjourn the meeting. Councilmember
Davis seconded the motion. The motion carried 5‐0 aye.
Mayor Sakrison adjourned the meeting at 8:02 PM.
APPROVED: ____________________ ATTEST: ____________________
David L. Sakrison Rachel Ellison
Mayor City Recorder/Asst. City
REPORT ON CITY/COUNTY
COOPERATION
MAYOR AND COUNCIL
REPORTS
APPROVAL OF BILLS
MOTION TO ADJOURN,
APPROVED
ADJOURNMENT
Page 81 of 135
September 28, 2010 Page 1 of 3
MOAB CITY COUNCIL
REGULAR MEETING
September 28, 2010
The Moab City Council held its Regular Meeting on the above date in
the Council Chambers of Moab City Offices, located at 217 East Center
Street, Moab, Utah. Mayor David L. Sakrison called the Pre‐Council
Workshop to order at 6:30 PM. In attendance were Councilmembers
Kyle Bailey, Kirstin Peterson, Sarah Bauman, Jeffrey Davis and Gregg
Stucki; City Manager Donna Metzler, City Recorder/Assistant City
Manager Rachel Ellison, Planning Director Jeff Reinhart, Community
Development Director David Olsen, Administrative Analyst/Economic
Development Specialist Kenneth F. Davey, Police Chief Mike Navarre
and City Engineer Rebecca Andrus.
Mayor Sakrison called the Regular City Council Meeting to order at 7:00
PM and Councilmember Davis led in the Pledge of Allegiance. Eighteen
(18) members of the audience were present.
There were no minutes to approve.
Under Citizens to be Heard, Sara Melnicoff stated that the Solutions
Group was celebrating their sixth year and in part due to their efforts,
no one had died on the parkway over the past winter. Ms. Melnicoff
acknowledged the Grand County High School Earth Club and their
recycling efforts. Ms. Melnicoff gave Mayor Sakrison the first annual
Solutions “Walking the Talk” award.
Under Community Development Department Update, Community
Development Director Olsen stated that the next Community
Development Block Grant process was starting up again.
Under Engineering Department Update, City Engineer Andrus reviewed
a written report.
Under Planning Department Update, Planning Director Reinhart stated
that the Haciendas and Portal Vista projects had slowed down and that
the Haciendas project would be ending in two to three weeks and that
the Portal Vista project would be progressing. Planning Director
Reinhart stated that there would be a Joint Planning Commission/City
Council Mobile Vendor Workshop.
A Police Department Update was not given.
A Public Works Department Update was not given.
Councilmember Bailey moved to approve the Use of Swanny City Park
by Energy Solutions on September 30, 2010 to Conduct a Community
Celebration and Grand County School District Charity Event.
Councilmember Bauman seconded the motion. The motion carried 5‐0
aye.
Councilmember Peterson moved to approve a Request for Use of City
Right‐of‐way by Stella Ann Lightfoot to Conduct a Sidewalk Sale on
October 8 and 9, 2010 at Various Locations on Main Street.
Councilmember Bailey seconded the motion. The motion carried 5‐0
aye.
REGULAR MEETING &
ATTENDANCE
CALL TO ORDER
APPROVAL OF MINUTES
CITIZENS TO BE HEARD
COMMUNITY DEVELOPMENT
UPDATE
ENGINEERING UPDATE
PLANNING UPDATE
POLICE UPDATE
PUBLIC WORKS UPDATE
USE OF SWANNY CITY PARK BY
ENERGY SOLUTIONS,
APPROVED
REQUEST FOR USE OF CITY
RIGHT‐OF‐WAY TO CONDUCT A
SIDEWALK SALE, APPROVED
Page 82 of 135
September 28, 2010 Page 2 of 3
Councilmember Peterson moved to approve a Request to Send
Proposed Ordinance #2010‐14 – An Ordinance Amending Various
Chapters of the Moab Municipal Code Pertaining to Accessory
Structures to Public Hearing. Councilmember Stucki seconded the
motion. The motion carried 5‐0 aye.
Councilmember Bauman moved to approve a Request to Send
Proposed Ordinance #2010‐21 – An Ordinance Adopting Various
International Codes to Public Hearing. Councilmember Peterson
seconded the motion. The motion carried 5‐0 aye.
Councilmember Bauman moved to approve a Request to Send
Proposed Ordinance #2010‐06 – An Ordinance Amending Code
Chapters 17.72.100 through 17.72.240 that Address the Board of
Adjustments to Public Hearing. Councilmember Bailey seconded the
motion. The motion carried 5‐0 aye.
Councilmember Bailey moved to approve Proposed Resolution #17‐
2010 – A Resolution Regarding a $25,000 Allocation of Real Estate
Transfer Assessment Funds to Help Finance the Cinema Court
Affordable Housing Project. Councilmember Bauman seconded the
motion. The motion carried 5‐0 aye.
There was no Correspondence to be Read.
Under Administrative Report, City Manager Metzler stated that city
staff would conduct ten interviews for the Moab Recreation Aquatic
Center (MRAC) Director position out of 31 applicants. City Manager
Metzler then stated that there were temporary recycling containers on
Main Street and that she had met with the Nature Conservancy, the
Division of Water Quality, the Division of Wildlife Resources and the
Water Rights Attorney for the Nature Conservancy. City Manager
Metzler continued that the state had decided that the ammonia level
was too high in the Waste Water Treatment Plant’s effluent for the
Nature Conservancy to use and that their project could not continue as
configured.
A Report on City/County Cooperation was not given.
Under Mayor and Council Reports, Mayor Sakrison stated that the
Millcreek Bridge project should be completed by the end of November
and that he had attended the annual Utah League of Cities and Towns
convention in Salt Lake City.
Councilmember Bauman stated that she had attended an Affordable
Housing Task Force meeting and that impact fee recommendations
were being developed.
Councilmember Stucki moved to pay the bills against the City of Moab
in the amount of $199,182.01. Councilmember Davis seconded the
motion. The motion carried 5‐0 aye by a roll‐call‐vote.
Councilmember Bailey moved to adjourn the meeting. Councilmember
Peterson seconded the motion. The motion carried 5‐0 aye.
Mayor Sakrison adjourned the meeting at 8:12 PM.
REQUEST TO SEND PROPOSED
ORDINANCE #2010‐14 TO
PUBLIC HEARING, APPROVED
REQUEST TO SEND PROPOSED
ORDINANCE #2010‐21 TO
PUBLIC HEARING, APPROVED
REQUEST TO SEND PROPOSED
ORDINANCE #2010‐06 TO
PUBLIC HEARING, APPROVED
PROPOSED RESOLUTION #17‐
2010, APPROVED
READING OF
CORRESPONDENCE
ADMINISTRATIVE REPORTS
REPORT ON CITY/COUNTY
COOPERATION
MAYOR AND COUNCIL
REPORTS
APPROVAL OF BILLS
MOTION TO ADJOURN,
APPROVED
Page 83 of 135
September 28, 2010 Page 3 of 3
APPROVED: ____________________ ATTEST: ____________________
David L. Sakrison Rachel Ellison
Mayor City Recorder/Asst. City Mgr.
ADJOURNMENT
Page 84 of 135
MOAB.FINAL.TM DRAFT.DOCX1
T E C H N I C A L M E M O R A N D U M
UDWQ POTW Nutrient Removal Cost Impact Study:
Analysis of Moab City Wastewater Treatment Plant
PREPARED FOR: Utah Division of Water Quality
PREPARED BY: CH2M HILL
COPIES: Moab Wastewater Treatment Plant
DATE: June 2010
In partial fulfillment of the Utah Division of Water Quality Publicly Owned Treatment Works
(POTW) Nutrient Removal Cost Impacts Study, this Technical Memorandum (TM) summarizes
the process, financial and environmental evaluation of Moab City Wastewater Treatment
Plant (MWWTP) to meet the four tiers of nutrient standards presented in Table 1.
The thirty mechanical POTWs in the State of Utah were categorized into five groups to
simplify process alternatives development, evaluation, and cost estimation for a large
number of facilities. Similar approaches to upgrading these facilities for nutrient removal
were thus incorporated into the models developed for POTWs with related treatment
processes. The five categories considered were as follows:
• Oxidation Ditch (OD)
• Activated Sludge (AS)
• Membrane Bioreactor (MBR)
• Trickling Filter (TF)
• Hybrid Process (Trickling Filter/Solids Contact (TF/SC) or Trickling
Filter/Activated Sludge (TF/AS))
The MWWTP fits in the Trickling Filter category.
TABLE 1
Nutrient Discharge Standards for Treated Effluent
Tier Total Phosphorus, mg/L Total Nitrogen, mg/L
1N 0.1 10
1 0.1 No limit
2N 1.0 20
2 1.0 No limit
3 Base condition Base condition
Page 85 of 135
MOAB WASTEWATER TREATMENT PLANT
UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 2
1. Facility Overview
MWWTP has a design flow of 1.5 million gallons per day (mgd) and currently receives an
average annual influent flow of approximately 0.9 mgd. The facility operates a rock media
trickling filter system with primary treatment. Chlorine is added to the secondary clarifiers
for disinfection prior to discharge to the Colorado River. Primary solids and wasted solids
are stabilized by anaerobic digestion and dewatered with sludge drying beds. A process
flow diagram is presented in Figure 1 and an aerial photo of the POTW is shown in Figure 2.
The major unit processes are summarized in Table 2.
FIGURE 1
Process Flow Diagram
Page 86 of 135
MOAB WASTEWATER TREATMENT PLANT
UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 3
FIGURE 2
Aerial View of the Facility (Source: Google Earth)
TABLE 2
Summary of Major Unit Processes
Treatment step Number of Units Size, each Details
Primary Clarifiers 2 40-ft diameter 8-ft SWD
Trickling Filters 2 72-ft & 80-ft diameter 7-ft depth, rock
Secondary Clarifiers 5 40-ft diameter 7-ft SWD
Anaerobic Digestion 2 48-ft diameter, 35,600-ft3 Mesophilic
2. Nutrient Removal Alternatives Development
A nutrient removal alternatives matrix was prepared in order to capture an array of viable
approaches for TF facilities (See Attachment A). This matrix considers biological and
chemical phosphorus removal approaches as well as different activated sludge
configurations for nitrogen control. The alternatives matrix illustrates that there are several
strategies for controlling nutrient limits. The processes that were modeled and described in
the subsequent sections are considered proven methods for meeting the nutrient limits.
There may be other ways to further optimize to reduce capital and operation and
Page 87 of 135
MOAB WASTEWATER TREATMENT PLANT
UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 4
maintenance (O&M) costs that are beyond the scope of this project. This TM can form the
basis for an optimization study in the future should that be desired by the POTW.
MWWTP currently operates two rock media trickling filter units with primary treatment.
As with all of the POTWs, the approaches were developed with the goal of utilizing the
existing infrastructure to the maximum extent possible. Because the facility’s trickling filters
are relatively shallow (7ft depth) and utilize rock media as opposed to more efficient plastic
media, it was decided to move toward an activated sludge system as nutrient limits become
more stringent. Figure 3 shows the selected upgrade approach used between each tier of
nutrient control with the bullet points A through D describing each upgrade step:
A. From Tier 3 (existing) to Tier 2 phosphorus control, the existing primary and
secondary treatment system was supplemented with a metal-salt feed and
storage system for chemical phosphorus removal.
B. To go from Tier 2 to Tier 2N, the trickling filters were replaced with an
extended aeration process using oxidation ditches. New anaerobic basins
located between the primary clarifiers and aerobic zones provided an
environment for phosphorus release. The aerobic-anoxic zones within the
oxidation ditch allowed phosphorus uptake and nitrogen removal
(nitrification/denitrification). New secondary clarifiers that were designed
for solids separation of an activated sludge replaced the existing clarifiers. In
addition, a return activated sludge (RAS) pumping station was needed.
Metal-salt feed and storage remained as a redundant system for P removal.
C. To go from Tier 2 to Tier 1 phosphorus control, deep bed granular media
filters were added downstream of the existing secondary clarifier units. An
additional chemical feed point was implemented upstream of the filter
system.
D. To go from Tier 2N to Tier 1N, deep bed granular media filters were added
downstream of the new secondary clarifiers.
FIGURE 3
Upgrades Scheme for Meeting Increasingly More Stringent Nutrient Control
Page 88 of 135
MOAB WASTEWATER TREATMENT PLANT
UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 5
Data Evaluation, Initial Modeling, and Calibration
The selected progression of upgrades conceived for meeting the different tiers of nutrient
control for MWWTP was analyzed using the following four steps;
Step 1. Review, compile, and summarize the process performance data
submitted by the POTW;
Step 2. Develop and calibrate a base model of the existing POTW using the
summarized performance data;
Step 3. Build upon the base model by sequentially modifying it to incorporate
unit process additions or upgrades for the different tiers of nutrient
control and use model outputs to establish unit process sizing and
operating requirements;
Step 4. Develop capital and O&M costs for each upgrade developed in Step 3.
The facility information and data received by MWWTP per the initial data request was
evaluated to (a) develop, and validate the base process model, and (b) size facilities to
conserve the POTW’s current rated capacity. Table 3 provides a summary of the reported
information used as the model input conditions. See process modeling protocol for
additional information.
TABLE 3
Summary of Input Conditions
Input Parameter 2009 (1) 2029 (2) Design (3)
Flow, mgd 0.9 1.25 1.5
BOD, lb/day 2,000 (266 mg/L) 2,750 (264 mg/L) 3,300 (264 mg/L)
TSS, lb/day 1,870 (250 mg/L) 2,750 (264 mg/L) 3,300 (264 mg/L)
TKN, lb/day 310 (41 mg/L) 427 (41 mg/L) 512 (41 mg/L)
TP, lb/day 35 (5 mg/L) 52 (5 mg/L) 63 (6 mg/L)
(1) Historic conditions 2007-2009
(2) Projected by the POTW, and updated at the POTW Workshop October, 2009.
(3) Design maximum month capacity of POTW updated at the POTW Workshop October, 2009.
The main sizing and operating design criteria that were associated with the system upgrade
for MWWTP are summarized in Table 4.
Page 89 of 135
MOAB WASTEWATER TREATMENT PLANT
UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 6
TABLE 4
Main Unit Process Sizing and Operating Design Parameters
Design Parameter (Nutrient Tier) Value
Influent design temperature (All Tiers) 10 deg C
Anaerobic fraction of bioreactor (T2N, T1N) 15%
Anoxic fraction of bioreactor (T2N, T1N) 20% - 30%
Target metal:PO4-P molar Ratio (Tier 1 and 1N) 1:1, 2:1, 7:1 (1)
Metal-salt storage (All Tiers) 14 days
Granular filter loading rate (T1 and T1N) 5 gpm/ft2 (2)
(1)Target dosing ratio at the primary clarifiers, secondary clarifiers and upstream of polishing filter, respectively.
Note that polishing filter included in T1 and T1N only.
(2)Hydraulic loading rate at peak hourly flow
3. Nutrient Upgrade Approaches
The following paragraphs provide details of the upgrade approaches as presented
previously in Figure 3.
Tier 2 Phosphorus (A)
The effluent limit for Tier 2 alternatives is 1.0 mg/L total phosphorus. MWWTP can achieve
1.0 mg/L total phosphorus using a multi-point metal-salt addition approach. This approach
dosed metal-salt upstream of the primary clarifiers and secondary clarifiers. A metal-salt
storage building was required for housing both storage tanks and metering pumps. The
process flow diagram for this approach is shown in Figure 4.
Page 90 of 135
MOAB WASTEWATER TREATMENT PLANT
UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 7
FIGURE 4
Modifications to POTW for Tier 2 Nutrient Control
Tier 2N – Phosphorus & Nitrogen (B)
The effluent limit for this alternative is 1.0 mg/L total phosphorus and 20 mg/L total
nitrogen. Because of the favorable influent wastewater characteristics (i.e,. BOD: P = 40), a
biological nutrient removal process was implemented to achieve nutrient control and to
minimize the plants dependence on chemicals. Primary effluent was sent to an anaerobic
basin prior to entering an oxidation ditch. Existing secondary clarifiers was replaced with
larger 50-ft diameter units with a deeper SWD for enhanced settling of the mixed-liquor.
The new clarifier underflow system provided adequate capacity to convey settled solids
from the new activated sludge system. The metal-salt feed system remained from Tier 2 as a
standby process. A process flow diagram for this Tier 2N approach is shown in Figure 5.
FIGURE 5
Modifications to POTW for Tier 2N Nutrient Goal
Tier 1 –Phosphorus (C)
The effluent limit for this alternative is 0.1 mg/L total phosphorus. This approach builds
upon the Tier 2 approach for phosphorus control. The dosing rate of metal-salt was
increased from Tier 2. In addition, new granular media filters with chemical feed were
needed to remove particulate phosphorus from the liquid stream prior to final discharge.
The filtration system required secondary effluent pumps to provide adequate head, as well
as backwash pumps and other ancillary equipment. A process flow diagram for this
chemical phosphorus approach is shown in Figure 6.
Page 91 of 135
MOAB WASTEWATER TREATMENT PLANT
UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 8
FIGURE 6
Modifications to POTW for Tier 1 Nutrient Goal
Tier 1N – Phosphorus & Nitrogen (D)
The effluent limit for this alternative is 0.1 mg/L total phosphorus and 10 mg/L total
nitrogen. This approach combined the process elements proposed in both Tier 2N and Tier
1. First, this approach replaced the trickling filter system with oxidation ditches as described
in Tier 2N. It also incorporated granular media filters as presented in T1. The multi-point
chemical feed system remained as a redundant means of phosphorus removal. A process
flow diagram is shown as Figure 7.
Page 92 of 135
MOAB WASTEWATER TREATMENT PLANT
UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 9
FIGURE 7
Modifications to POTW for Tier 1N Nutrient Goal
4. Capital and O&M Cost Estimates for Nutrient Control
This section formalizes the cost-impact results from this nutrient control analysis. These
outputs were used in the financial cost model and subsequent financial analyses.
Table 5 presents a summary of the major facility upgrade components identified for meeting
each tier of nutrient control. For all Tiers, a metal-salt feed and storage facility was required
along with minor mechanical modification at the specific dosing points. Tier 1 also required
the addition of a granular media filter system with upstream metal-salt feed. Tier 2N
needed a BNR system using oxidation ditches with new secondary clarifiers and RAS/WAS
pumping. Tier 1N incorporated a granular media filtration system to the new activated
sludge treatment system.
TABLE 5
Page 93 of 135
MOAB WASTEWATER TREATMENT PLANT
UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 10
Major Facility Upgrade Summary
Processes Tier 2 Tier 2N Tier 1 Tier 1N
Metal-salt feed & storage system X X X X
Anaerobic basins X X
Oxidation Ditches (Basins, aerators, mixers) X X
Mixed-liquor distribution structure X X
Secondary clarifiers X X
RAS/WAS Pump Station X X
Granular media filtration system X X
The capital cost estimates shown in Table 6 were generated for the facility upgrades
summarized in Table 5. These estimates were prepared in accordance with the guidelines of
the Association for the Advancement of Cost Engineering (AACE) International and defined
as a Class 4 estimate. The expected accuracy range for the estimates shown in Table 6 is
-30%/+50%.
TABLE 6
Capital Cost Estimates ($ Million)
Unit Process Facility Tier 2 Tier 2N Tier 1 Tier 1N
Metal-Salt Feed Facility $0.630 $0.340 $0.660 $0.340
Oxidation Ditches $0.000 $3.630 $0.000 $3.630
Anaerobic Basin $0.000 $0.920 $0.000 $0.920
Mixed-Liquor Splitting Structure $0.000 $0.320 $0.000 $0.320
Secondary Clarifiers $0.000 $3.100 $0.000 $3.100
RAS/WAS Pump Station $0.000 $2.612 $0.000 $2.612
Secondary Effluent Pumps $0.000 $0.000 $1.210 $1.210
Deep Bed Filters $0.000 $0.000 $4.150 $4.150
TOTAL TIER COST $0.630 $10.922 $5.820 $16.082
December 2009 US Dollars
Incremental O&M costs associated with meeting each tier of nutrient standard were
generated for the years 2009 and 2029. The unit costs were either provided by the POTW or
assumed based on the average costs in the State of Utah, and are presented in Table 7. A
straight line interpolation was used to estimate the differential cost for the two years. O&M
costs for each upgrade included the following components:
• Biosolids management: hauling , use, and disposal
• Chemical consumption costs: metal-salt, and, polymer
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UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 11
• Power costs for the major mechanized process equipment: aeration, secondary effluent
pumps, backwash pumps and dewatering units
TABLE 7
Operating and Maintenance Unit Costs
Parameter Value
Biosolids hauling $20/wet ton
Biosolids tipping fee $20/wet ton
Roundtrip biosolids hauling distance (1) 42 miles
Ferric chloride $1000/ton
Polymer $1/lb
Power $0.07/kwh
(1) Provided by the POTW
Increased O&M relative to the current O&M cost (Tier 3) are presented in Table 8 and
shown graphically in Figure 8.
TABLE 8
Estimated Impact of Nutrient Control on O&M Costs
TIER 2 TIER 2N TIER 1 TIER 1N
2009 2029 2009 2029 2009 2029 2009 2029
Biosolids $0.04 $0.06 $0.00 $0.00 $0.04 $0.06 $0.02 $0.02
Metal-salt $0.05 $0.07 $0.00 $0.00 $0.04 $0.07 $0.01 $0.02
Polymer $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00 $0.00
Power $0.00 $0.00 $0.02 $0.03 $0.02 $0.02 $0.04 $0.05
Total O&M $0.09 $0.13 $0.02 $0.03 $0.10 $0.15 $0.07 $0.09
Note: $ Million (US) in December 2009
Costs shown are the annual differential costs relative to the base line O&M cost of the POTW
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UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 12
$0.00
$0.02
$0.04
$0.06
$0.08
$0.10
$0.12
$0.14
$0.16
$0.18
$0.20
2007 2012 2017 2022 2027 2032Annual Differential O&M Cost ($1M)Year
Tier 2
Tier 2N
Tier 1
Tier 1N
FIGURE 8
Impact of Nutrient Control on O&M Costs over 20 year evaluation period
5. Financial Impacts
This section presents the estimated financial impacts that will result from the
implementation of nutrient discharge standards for MWWTP. Financial impacts were
summarized for each POTW on the basis of three primary economic parameters: 20-year life
cycle costs, user charge impacts, and community financial impacts. The basis for the
financial impact analysis is the estimated capital and incremental O&M costs established in
the previous sections.
Life Cycle Costs
Life cycle cost analysis refers to an assessment of the costs over the life of a project or asset,
emphasizing the identification of cost requirements beyond the initial investment or capital
expenditure.
For each treatment upgrade established to meet the studied nutrient limits (Tier 2, Tier 2N,
Tier 1, and Tier 1N), a multi-year life cycle cost forecast was developed that is comprised of
both capital and O&M costs. Cost forecasts are organized with initial capital expenditures in
year 0 (2009), and incremental O&M forecasts from year 1 (2010) through year 20 (2029). The
cost forecast for each treatment alternative was developed in current (2009) dollars, and
discounted to yield the net present value (NPV).
The NPV was divided by the estimated 20-year nutrient discharge mass reduction for each
tier, resulting in a cost per pound estimate for nutrient removal. This calculation represents
an appropriate matching of costs with receiving stream load reduction over the same time
period. Table 9 presents the results of the life cycle cost analysis for MWWTP.
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UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 13
TABLE 9
Nutrient Removal: 20-Year Life Cycle Cost per Pound 1
Tier 2 Tier 2N Tier 1 Tier 1N
Phosphorus Removal (pounds)2 166,285 166,285 225,697 225,697
Nitrogen Removal (pounds)2 - 1,122,213 - 1,782,338
Net Present Value of Removal Costs3 2,327,524$ 11,263,061$ 7,945,950$ 17,518,681$
NPV: Phosphorus Allocation 2,327,524 2,327,524 7,945,950 7,945,950
NPV: Nitrogen Allocation4 8,935,538 9,572,731
TP Cost per Pound5 14.00$ 14.00$ 35.21$ 35.21$
TN Cost per Pound5 7.96$ 5.37$
2 - Total nutrient removal over a 20-year period, from 2010 through 2029
3 - Net present value of removal costs, including capital expenditures and incremental O&M over a 20-year period
4 - For simplicity, it was assumed that the nitrogen cost allocation was the incremental difference between net present value costs
across Tiers for the same phosphorus limit (i.e. Tier 2 to Tier 2N); differences in technology recommendations may result in different
cost allocations for some facilities
1 - For facilities that are already meeting one or more nutrient limits, "meets limit" is displayed for nutrient removal mass and "NA" is
displayed for cost per pound metrics
5 - Cost per pound metrics measured over a 20-year period are used to compare relative nutrient removal efficiencies among
treatment alternatives and different facilities
Customer Financial Impacts
The second financial parameter measures the potential impact to user rates for those
customers served by the POTW. The financial impact was measured both in terms of
potential rate increases for the POTW’s associated service provider, and the resulting
monthly bill impacts for the typical residential customer of the system.
Customer impacts were estimated by calculating annual increased revenue requirements for
the POTW. Implementation of each treatment upgrade will increase the annual revenue
requirements for debt service payments (related to initial capital cost) and incremental O&M
costs.
The annual cost increase was then divided by the number of customers served by the
POTW, as measured by equivalent residential units (ERUs), to establish a monthly rate
increase per ERU. The monthly rate increase associated with each treatment alternative was
estimated by adding the projected monthly rate increase to the customer’s current average
monthly bill. Estimated financial impacts for customers of the MWWTP are presented in
Table 10.
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UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 14
TABLE 10
Projected Monthly Bill Impact per Equivalent Residential Unit (ERU) for Treatment Alternatives
Tier 2 Tier 2N Tier 1 Tier 1N
Initial Capital Expenditure 629,000$ 10,907,000$ 5,998,000$ 16,252,000$
Estimated Annual Debt Service1 50,500$ 875,200$ 481,300$ 1,304,100$
Incremental Operating Cost2 95,800 20,500 106,600 74,900
Total Annual Cost Increase 146,300$ 895,700$ 587,900$ 1,379,000$
Number of ERUs 3,770 3,770 3,770 3,770
Annual Cost Increase per ERU $38.81 $237.59 $155.94 $365.78
Monthly Cost Increase per ERU3 $3.23 $19.80 $13.00 $30.48
Current Average Monthly Bill4 $18.65 $18.65 $18.65 $18.65
Projected Average Monthly Bill5 $21.88 $38.45 $31.65 $49.13
Percent Increase 17.3%106.2%69.7%163.4%
1 - Assumes a financing term of 20 years and an interest rate of 5.0 percent
3 - Projected monthly bill impact per ERU for each upgrade, based on estimated increase in annual operating costs
4 - Estimated 2009 average monthly bill for a typical residential customer (ERU) within the service area of the facility
5 - Projected average monthly bill for a typical residential customer (ERU) if treatment upgrade is implemented
2 - Incremental annual increase in O&M for each upgrade, based on chosen treatment technology, estimated for first operational
year
Community Financial Impacts
The third and final parameter measures the financial impact of nutrient limits from a
community perspective, and accounts for the varied purchasing power of customers
throughout the state. The metric is the ratio of the projected monthly bill that would result
from each treatment alternative to an affordable monthly bill, based on a parameter
established by the State Water Quality Board to determine project affordability.
The Division employs an affordability criterion that is widely used to assess the
affordability of projects. The affordability threshold is equal to 1.4 percent of the median
annual gross household income (MAGI) for customers served by a POTW. The MAGI
estimate for customers of each POTW is multiplied by the affordability threshold parameter,
then divided by 12 (months) to determine the monthly ‘affordable’ wastewater bill for the
typical customer.
The projected monthly bill for each nutrient limit was then expressed as a percentage of the
monthly affordable bill. The resulting affordability ratio for each nutrient limit for the
MWWTP is shown in Table 11.
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TABLE 11
Community Financial Impacts: Affordability of Treatment Alternatives
Tier 2 Tier 2N Tier 1 Tier 1N
Median Annual Gross Income (MAGI)1,2 28,700$ 28,700$ 28,700$ 28,700$
Affordability Threshold (% of MAGI)3 1.4%1.4%1.4%1.4%
Monthly Affordability Criterion $33.48 $33.48 $33.48 $33.48
Projected Average Monthly Bill $21.88 $38.45 $31.65 $49.13
Meets State's Affordability Criterion?Yes No Yes No
Estimated Bill as % of State Criterion 65%115%95%147%
1 - Based on the average MAGI of customers within the service area of the facility
2 - MAGI statistics compiled from 2008 census data
3 - Parameter established by the State Water Quality Board to determine project affordability for POTWs
6. Environmental Impacts of Nutrient Control Analysis
This section summarizes the potential environmental benefits and impacts that would result
from implementing the process upgrades established for the various tiers of nutrient control
detailed in Section 3. The following aspects were considered for this evaluation:
• Reduction of nutrient loads from POTW to receiving water bodies
• Changes in chemical consumption
• Changes in biosolids production
• Changes in energy consumption
• Changes in emissions from biosolids hauling, disposal and energy consumption
As per the data received from MWWTP and per process modeling of the base condition
(Tier 3), MWWTP is able to achieve some nutrient removal with its existing infrastructure,
but not enough to meet the effluent limits of the specified Tiers of nutrient standards. Table
12 summarizes the annual reduction in nutrient loads in MWWTP effluent discharge if the
process upgrades were implemented. The values shown are for the current (2009) flow and
load conditions. It should be noted that any increase in flow or load to the POTW will result
in higher reductions.
TABLE 12
Estimated Environmental Benefits of Nutrient Control
Tier 2 Tier 2N Tier 1 Tier 1N
Total phosphorus removed, lb/year 6,500 6,500 8,965 8,965
Total nitrogen removed, lb/year ---- 47,760 ---- 75,155
Note: Nutrient loads shown are the annual differential loads relative to the baseline (Tier 3)
condition of the POTW for the year 2009.
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UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 16
The nutrient content of POTWs’ discharges and their receiving waters were also
summarized to examine the potential of various treatment alternatives for reducing nutrient
loads to those water bodies. The POTW loads were paired with estimated loads in the
upstream receiving waters to create estimated downstream combined loads. Those
combined stream and POTW loads could then be examined for the potential effects of future
POTW nutrient removal alternatives. The average total nitrogen and phosphorus
concentrations discharged by each POTW were either provided by the POTW during the
data collection process or obtained from process modeling efforts. Upstream receiving
historical water quality data was obtained from STORET. Data from STORET was
summarized in order to yield average total nitrogen and total phosphorus concentrations
that could then be paired with the appropriate POTW records. It should be noted that the
data obtained from STORET were not verified by sampling and possible anomalies and
outliers could exist in historical data sets due to certain events or errors in measurement.
Table 13 shows the total phosphorus and total nitrogen concentration discharged by
MWWTP to its receiving waters for baseline condition (Tier 3) and for each Tier of nutrient
standard. The STORET ID from where historical water quality data were obtained is also
presented in the Table.
The process upgrades established to meet the four tiers of nutrient standards require
increased energy consumptions, chemical usage and biosolids production. Regular metal-
salt addition would be required to meet the more stringent phosphorus limits. This would
result in increased chemical sludge generation and consequently increased biosolids
production. Process modifications to meet the total nitrogen limits would also result in
increased energy consumption and biosolids productions. Table 14 summarizes these
environmental impacts of implementing the process upgrades to achieve the various tiers of
nutrient control. The values shown are on an annual basis, for the current (2009) flow and
load conditions and indicate a differential value relative to the base line condition.
TABLE 13
Estimates of Average TN and TP Concentrations for Baseline and Cumulative Treatments to Receiving Waters
(mg/L)
Tier 3 Tier 2 Tier 2N Tier 1 Tier 1N
STORET
LOCATION
STORET
ID
FLOW
(cfs) TP TN TP TN TP TN TP TN TP TN
MWWTP ---- 1.39 3.37 37.00 1.0 N/A 1.0 20 0.1 N/A 0.1 10
Colorado
River 4956540 6652.49 0.16 1.11 ---- ---- ---- ---- ---- ---- ---- ----
Combined Concentrations 0.16 1.11 0.16 N/A 0.16 1.11 0.16 N/A 0.16 1.11
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UDWQ POTW NUTRIENT REMOVAL COST IMPACT STUDY 17
TABLE 14
Estimated Environmental Impacts of Nutrient Control
Tier 2 Tier 2N Tier 1 Tier 1N
Chemical Use:
Metal-salt use, lb/year 97,795 750 86,825 29,515
Polymers, lb/year 780 0 750 400
Biosolids Management:
Biosolids produced, ton/year 78 0 75 40
Average yearly hauling distance(1) 150 0 145 76
Particulate emissions from hauling trucks, lb/year (2) 8 0 8 4
Tailpipe emissions from hauling trucks, lb/year(3) 19 0 18 10
CO2 emissions from hauling trucks lb/year(4) 1895 0 1815 970
Energy Consumption:
Annual energy consumption, kwh 0 327,359 284,909 609,016
Air pollutant emissions, lb/year (5)
CO2 0 295,278 256,988 549,333
NOx 0 458 399 853
SOx 0 393 342 731
CO 0 21 19 40
VOC 0 3 2 5
PM10 0 6 6 12
PM2.5 0 3 3 6
Note: Values shown are the annual differential values relative to the base line condition (Tier 3) of the POTW for
the year 2009
(1) Roundtrip hauling distance of 42 miles, assuming the POTW uses 22 ton trucks for hauling biosolids to the
landfill.
(2) Includes PM10 and PM2.5 emissions in pounds per year. The emission factors to estimate particulate emissions
were derived using the equations from AP-42, Fifth Edition, Vol. I, Section 13.2.1.: Paved Roads (11/2006).
(3) Tailpipe emissions in pounds per year resulting from diesel combustion of hauling trucks were based on
Emission standards Reference guide for Heavy-Duty and Nonroad Engines, EPA420-F-97-014 September 1997.
It was assumed that the trucks would meet the emission standards for 1998+.
(4) CO2 emission factor in pounds per year for hauling trucks were derived from Rosso and Chau, 2009, WEF
Residuals and Biosolids Conference Proceedings.
(5) Emission factors for electricity are based on EPA Clean Energy Power Profiler
(http://www.epa.gov/cleanenergy/energy-and-you/how-clean.html) assuming PacifiCorp UT region commercial
customer and AP-42, Fifth Edition, Vol. I, Chapter 1, Section 1.1.: Bituminous and Sub bituminous coal
Combustion (09/1998).
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City of Moab
Holiday Schedule
2011
All City Offices will be closed on the following holidays during 2011:
Monday, January 17 Dr. Martin Luther King Jr. Day
Monday, February 21 Presidents’ Day
Monday, May 30 Memorial Day
Monday, July 4 Independence Day (observed)
Monday, July 25 Pioneer Day (observed)
Monday, September 5 Labor Day
Friday, November 11 Veterans’ Day
Thursday, November 24 Thanksgiving Day
Friday, November 25 Day After Thanksgiving
Monday, December 26 Christmas Day (observed)
Published in the Times-Independent, October 21 and 28, 2010.
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City of Moab
AMENDED
Holiday Schedule 2010
All City Offices will be closed on the following holidays during 2010:
Friday, January 1 New Year’s Day 2010
Monday, January 18 Dr. Martin Luther King Jr. Day
Monday, February 15 Presidents’ Day
Monday, May 31 Memorial Day
Monday, July 5 Independence Day (observed)
Friday, July 23 Pioneer Day (observed)
Monday, September 6 Labor Day
Thursday, November 11 Veterans’ Day
Thursday, November 25 Thanksgiving Day
Friday, November 26 Day After Thanksgiving
Friday, December 24 Christmas Day (observed)
*Friday, December 31 New Year’s Day 2011 (observed)*
Published in the Times-Independent, October 21 and 28, 2010.
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City of Moab
Regular Council Meeting Schedule
2011
The City of Moab will hold Regular City Council Meetings at 7:00 PM with workshops
beginning at 6:30 PM on the second and fourth Tuesdays of each month. All Regular
City Council Meetings will be held in the Moab City Council Chambers at 217 East
Center Street, Moab, Utah. Meeting dates will be as follows:
January 11 January 25
February 8 February 22
March 8 March 22
April 12 April 26
May 10 May 24
June 14 June 28
July 12 July 26
August 9 August 23
September 13 September 27
October 11 October 25
November 8 November 22
December 13
/s/ Rachel Ellison
City Recorder/Assistant City Manager
Published in the Times-Independent, October 21 and 28, 2010.
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