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HomeMy Public PortalAboutNPDES February 2020 UpdatesGerald S. Mee Jr. Superintendent TO: FROM: DATE: RE: TOWN OF WATERTOWN DEPARTMENT OF PUBLIC WORKS 124 ORCHARD STREET WATERTOWN MA 02472 Members of the Stormwater Advisory Committee Matthew Shuman, P.E., Town Engineer February 19, 2020 MS4/NPDES Permit Year 2 Update (P) 617-972-6420 (F) 617-972-6402 Attached, please find a copy of MS4 Year 2 Requirements that was provided to DPW by Laura Schifman, MassDEP Stormwater Coordinator. Below, please find updates regarding the Town's progress in meeting its Year 2 commitments: Public Education and Outreach • Working with the Mystic River Watershed Association, the Town has printed brochures regarding stormwater impacts of Dumpster Maintenance and Automotive Industries. These brochures will be distributed by the Health Department, Zoning Enforcement, and Weights and Measures during site visits/inspections. The brochures will also be posted on the web -site. Distribution of the brochures will meet the public education requirement for businesses and industry. • The Responsible Dog Ownership in Watertown brochure is available at the Town Clerk's office and is being distributed with annual dog licenses. • An education message was included in the Town Manager's fall newsletter related to the proper disposal of leaf litter. • Educational signage was installed at one of the bioswales on Edenfield Ave. Public Participation • DPW staff installed approximately 150 catch basin stencils at various locations during fall 2019. • The annual requirements of the MS4 permit require the annual report to be submitted and available to the public, with an annual opportunity to review implementation of the Town's Stormwater Management Plan (SWMP). DPW requests that review of the SWMP be formally placed on the agenda of a future SAC meeting. NStormwater Advisory CommitteeWPDES February 2020 Updates. doc Illicit Discharae Detection and Elimination • An Addendum to the Town's written IDDE Plan was developed and submitted to EPA to comply with the additional requirements of the MS4 permit. The Town requested credit for its existing IDDE program and exemption from the requirement to rank each outfall. • The Town continues its IDDE program and posts quarterly updates to the Town's web -page at: http://www.watertowndpw.org/181/Illicit-Discharge-Detection-Elimination-. Investigations in sub- areas 6, 8, 11, 18, 20, 99, 109 and BEL continue. The Town continues to coordinate its IDDE and sanitary sewer inflow and infiltration (1/1) programs. This year's 1/1 contract partially overlaps with sections of sub -area 99 that experience high groundwater and have a high probability of sewer -drain communication. As issues are identified in the drainage system through the IDDE program, the corresponding sewer areas are reviewed as part of the 1/1 program. The Town has had success in reducing or eliminating contamination in the drainage system by addressing deficiencies in the sewer system. Construction Site Stormwater Management • DPW continues inspections of development sites during construction, including initial inspection of erosion controls and final inspection. DPW sign -off is required prior to issuance of a Certificate of Occupancy by the Building Department. • The Town's Stormwater Management and Erosion Control Rules and Regulations will be updated to address construction waste handling. Post -Construction Stormwater Management • DPW continues to enforce the Stormwater Management and Erosion Control Ordinance. • The Town is participating in a Technical Assistance program with the EPA related to nutrient control. As part of the support, consultants will be reviewing the Town's Stormwater Management and Erosion Control Ordinance and Rules and Recommendations and providing feedback on how to update them to comply with the requirements of the current MS4 permit. • The proposed settlement of various litigation related to the MS4 permit would move the deadline for updating the Town's Ordinances from the end of Year 2 to the end of Year 3. Good Housekeeping The MS4 permit requires that the Town take steps to ensure that no catch basin more than 50% full. During Permit Year 2, the Town began collecting catch basin cleaning information using GIS. Over 3,500 catch basins were cleaned. Information including depth of sediment, depth to pipe, and depth to bottom of structure was also collected. This information will be used to develop an optimization plan, although a second year of data is desired to finalize the optimization plan. The initial data will be reviewed to provide preliminary recommendations for enhanced catch basin cleaning to ensure that no catch basin is more than 50% full. The Town has completed a Standard Operating Procedure (SOP) for Parks and Open Space Management. NStormwater Advisory CommitteeWPDES February 2020 Updates. doc • The Town has engaged Weston and Sampson Engineers to develop Stormwater Pollution Prevention Plans (SWPPPs) for the DPW property, the Howard Street laydown area, Ridgelawn Cemetery, and the Recycling Center. • DPW is in the process of developing an Operations and Maintenance Plan for municipally owned Best Management Practices (BMPs). • Two tree trenches will be constructed as part of the 2019 Road Reconstruction Program and ten as part of the 2020 Road Reconstruction Program. TMDL Requirements • The Town selected four recently completed projects to evaluate the potential for phosphorus reduction through redevelopment and installation of stormwater management practices. The projects included: installation of sub -surface infiltration systems at the Municipal Parking lot, redevelopment of 65 Grove Street, redevelopment of 655 Mt. Auburn Street (CVS), and redevelopment of 570 Arsenal Street (Marriott Hotel). • Phosphorus loads were classified as structural (from an infiltration practice) or non-structural (change in land use or creation of pervious area from impervious area). • The redevelopment or retrofitting of the four sites, when combined, provide a removal of approximately 10.3 lb/year of phosphorus from the MS4. This is approximately 0.8% of the 1,283 lb/year of phosphorus that the Town is required to remove from the MS4. • As part of the 2018 road reconstruction program, two tree trenches were installed on Edgecliff Road. Phosphorus load reductions were estimated for these two structures at 0.18 Ib/yr, or 0.01 % of the Town's required phosphorus load reduction. • The Town continues to collate previous projects to estimate phosphorus load reductions as a result of redevelopment. • The Town continues to monitor the potential impacts of litigation on the TMDL requirements, including phasing of the implementation plan and targeted phosphorus load reductions. NStormwater Advisory CommitteeWPDES February 2020 Updates. doc