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HomeMy WebLinkAboutLexington SWPPP Inspections Memo - May 2024MEMORANDUM June 17, 2024 Mr. Marc Valenti, CPWP-S Manager of Operations Lexington DPW 201 Bedford Street Lexington, MA 02420 RE: NPDES Phase II Stormwater Assistance Pollution Prevention & Good Housekeeping for Municipal Operations Spring 2024 Quarterly SWPPP Observation Dear Mr. Valenti, In order to fulfill the requirements of the 2016 National Pollution Discharge Elimination System (NPDES) Stormwater General Permit, Environmental Partners Group, LLC. (EP) conducted site visits of Town-owned facilities that maintain a Stormwater Pollution Prevention Plan (SWPPP). These facilities require a quarterly observation, in accordance with Section 2.3.7.b.iii of the Stormwater General Permit. On May 16, 2024, EP visited the two Town-owned facilities that require SWPPP observations: the Department of Public Works and the Compost Facility. These site visits were conducted during wet weather conditions. The SWPPP observations included touring the grounds of each property, observing all storage stockpiles, material loading areas, fueling stations, equipment operation and maintenance areas, vehicle washing areas, salt piles, areas of erosion, and waste handling and disposal areas. In addition, Structural Control Measures, such as catch basins, BMPs, and inlet/outlets, were observed and determined to be effectively operating or in need of maintenance or replacement. Observations were recorded in the Site Observation Reports, attached in Appendices A and B. The site visits of the Department of Public Works (DPW) and Compost Facility found that the sites are generally in compliance with respect to the Pollution Prevention and Good Housekeeping minimum control measures of the Stormwater General Permit. The only areas that require attention are described below. 2 of 3 envpartners.com • Department of Public Works (DPW) o Minor amount of trash observed throughout the stormwater BMPs. o The Town continues cutting back vegetation within its stormwater basins periodically to ensure that the plant growth does not limit the storage capacity of the basins. The Town stated that Essex Horticultural inspects the stormwater basins on a bi-annual basis and maintains them as necessary. o During the last inspection, the Town stated that the facility experienced moderate flooding during winter rain events. During the time of this inspection, no flooding was observed adjacent to the culvert that is north of the Offices. Minor amount of pooling was observed in some areas of the facility. o During previous inspections, a pipe was observed entering the catch basin in front of the Salt/Sand Shed, and flow was observed during dry weather.  In March 2023, EP spoke with a neighboring resident of the DPW, and they believed a stream was culverted and the pipe observed at the DPW could contain this stream water. The neighbor indicated that the stream may have been culverted years before the DPW was built. The Town should determine the source of this pipe, confirm that this pipe does convey this culverted stream, and update the stormwater mapping accordingly. o Salt was found eroding from the Salt/Sand Shed. Routine sweeping along the area is recommended. o A stormwater sample was taken at the outfall north of the DPW and was observed as being clear with no obvious odors or floatables. Should the outfall be inundated with sediment or impeded by overgrown and dead vegetation, the Town should consider routinely maintaining the area. Currently, there is no immediate maintenance needed. o The Town and EP are working together to update the mapping within the DPW facility and throughout the remainder of the town. The mapping updates throughout the town include retiring and/or combining BMP locations. • The Compost Facility o The two catch basins on site are buried and no longer convey stormwater due to the regrading of the nearby road. The SWPPP should be updated to reflect these changes. The buried catch basins likely no longer need to be observed quarterly. Also, the Town should consider decommissioning the discharge point of the catch basins o The outlet west of the hazardous waste collection area should be routinely maintained. During the time of inspection, debris and vegetation were cleared, and the riprap along the entrance of the facility had been replenished. A stormwater sample was taken at the mouth of the outlet and was observed as being light brown and clear, with no obvious odors. o Access to the outlet discharging into the woods, located in the southeast portion of the compost facility, was partially obstructed by construction debris and overgrown vegetation. Routine clearing is recommended to allow proper access. A stormwater sample was taken at the mouth of the outfall and was observed as being light brown and clear, with no obvious odors. 3 of 3 envpartners.com o Empty oil drums were found in the hazardous waste collection area. If waste oil collection is collected and stored in the facility, it should be placed on a concrete palette, have proper signage, and include an accessible spill kit. The Town continues to maintain their stormwater BMPs. The replaced riprap behind the salt shed continues to be in good condition. The catch basins and proprietary separator BMPs (Hydro International) within the facility should be cleaned on an as-needed basis and/or per the factory O&M manual. Additionally, the Town has purchased a vactor truck to aid in the cleaning of stormwater proprietary separator BMPs and other stormwater utilities. The vactor will be deployed and utilized within this fiscal year. Lastly, since the last inspection, the Town has installed riprap along the entrance of the compost facility. With the new addition of the riprap, the Town hopes the riprap will be able to collect any sediment or washout prior to discharging into the wetland. The Town is hoping to enhance the riprap near term and add additional riprap where needed. Corrective actions taken in response to these findings should be documented in writing by the facility managers of the individual facilities, with a copy kept on file with other Stormwater General Permit compliance documentation. The next SWPPP site visit should be completed in the next quarter (between July and September 2024). Please do not hesitate to email or call us if you have any questions or require any additional information. Sincerely, Environmental Partners Group, LLC Natalie Pommersheim Project Manager P: 617.657.0257 E: nmp@envpartners.com Karen Chan Project Scientist P: 617.657.0271 E: knc@envpartners.com CC: John Zaccardi – Town of Lexington DPW Eric Kelley, PE, CHMM, LEED GA – Environmental Partners Attachments Certification Page Appendix A. DPW Site Observation Report, Figure, and Photos Appendix B. Compost Facility Site Observation Report, Figure, and Photos CERTIFICATION “I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.” Printed Name ___________________________________________ Signature ________________________________________________ Date _________________________________________ envpartners.com APPENDIX A Department of Public Works Site Observation Report, Figure, and Photos Figure Exported: 8/21/2019 By: mroberts Using: \\woodardcurran.net\shared\Projects\0227871.05 Lexington MA - 2018-2019 MS4 Support\wip\GIS\Project Files\DPW_SWPPP_Figure2_11x17_August2019.mxd"¥ "¥ "¥"¥"¥ "¥ "¥"¥ "¥ "¥ "¥ "¥ "¥"¥ "¥ "¥ "¥ "¥ "¥ "¥ "¥ "¥ "¥ "¥ "¥ "¥ "¥ "¥ "¥ !!2 !!2 !!2 !!2 !!2 !!2 !!2 !!2 !!2 ! # #;;;;;;;;; AsphaltEmulsifier Salt ShedTrailersPlowsDPW Buildin g Equipment St o r a g e Maintenance Bay WashBay FluidBay Offices ParkingCold Storage;;;;TrailersLoading Dock;TemporaryLandscaping Storage PublicSand CatchBasinFixtures PVCPipeCardboard Dumpster Recycling Plastic TotersWaste Dumpster Pallets Scrap MetalRoll-Off Dumpster BrineSolutionTanks Concrete Blocks FuelingStation TransformerDiesel Generator Manufactur e d S y s t e m Infiltration C h a m b e r Manufactured SystemInfiltration ChamberManufactur e d S y s t e m I n f i l t r a t i o n C h a m b e r Manufactured SystemInfiltration ChamberDownstreamDefender ManufacturedSystemGreen Roof RainGarden RainGarden RainGarden Rain Garde n Rain Garden ConstructedStormwater WetlandInfiltration - Porous PavementIn f i l t r a t ion - Po rou s Pa v emen t Vegetated Swale Vegetated Swale Ve g e t a te d Swa le SedimentForebay SedimentForebay Sediment Forebay SedimentForebay «2«1 «3 «4 Hydrant F Service Layer Credits: Source: Esri, Ü 0 50 100 150 20025 FeetLegend #Outfall DPW Site Features !!2 Manhole "¥Catchbasin Collector Culvert Open Channel Drainage Areas Stormwater Treatment CITY OF LEXINGTON, MASWPPPDPW SiteDrainage FIGURE 3-2 DATE: AUGUST 2019 JOB NO.: 0227871.05 DOC: DPW_SWPPP_Figure2_11x17_August2019.mxd DRAWN BY: JS/JC 1 " = 100 'SCALE: DPW SWPPP QUARTERLY SITE OBSERVATION CHECKLIST Date: May 16, 2024 Time: 11:30-12:30 PM Inspector(s) Name(s): Karen Chan, Environmental Partners Inspector(s) Signature(s): Weather Conditions During Site Visit: Light rain (on and off), 60s Description of Any Discharge Occurring at the Time of the Site Visit: Wet weather flow observed discharging into the vegetated swale adjacent to the parking lot. Conduct a thorough observation of the entire facility and grounds Areas to Observe Good Action Needed? (Routine) “Corrective Action”† Needed? Action Complete d? (Date) Potential Pollutant Sources: Description of problem: Parking Lots Generator Transformer Cold Storage Dumpsters Recycling Collection & Storage Areas Yard/Storage Area Salt Shed and Loading Area Snow Stockpile Area Asphalt Emulsifier Tank Brine Solution Tank Hydrant (by the sediment forebay) Fueling Station General Facility Grounds & Outfall: Good Action Needed? (Routine) “Corrective Action”† Needed? Action Complete d? (Date) Observe catch basins, outfalls, sediment forebays, and rain gardens for evidence of damage, erosion or any discharge of pollutants. Ensure that facility grounds show no signs of poor housekeeping (e.g., materials, residues, or trash that may come in contact with stormwater). Ensure there are no spots, pools, puddles, or other traces of oil, grease, or other chemicals on the ground around the facility, either liquid or solid. Ensure there is no evidence of offsite tracking of materials and no blowing of raw, final, or waste materials outside of the operational areas. Ensure there are no leaks or spills from equipment, drums or other containers, or containers in poor condition outside the facility. †Corrective Action” is triggered for systemic problems with control measures (e.g., if a dumpster lid is occasionally left open, this does not trigger “corrective action;” however, if a dumpster lid is missing or inoperable, this triggers corrective action. If an area needs routine sweeping, this does not trigger “corrective action;” however, if an area needs sweeping and is not being swept because supplies are not available or staff is not assigned, this triggers corrective action.) DPW SWPPP QUARTERLY SITE OBSERVATION CHECKLIST Do any control measures need maintenance, repairs, or replacement? Yes* No If yes, describe: The Town should continue cutting back vegetation within its stormwater basins periodically to ensure that the plant growth does not limit the storage capacity of the basins. Some trash was noted in all BMPs. Inspect subsurface chambers and clean outs as necessary. Any additional control measures needed to comply with permit requirements? Yes* X No If yes, describe: Identification of any previously unidentified discharges from the Site: Yes* No If yes, describe: Describe any incidences of noncompliance observed (i.e., corrective action needed), summary of corrective actions taken and date initiated and completed (attach additional sheets if necessary): Are modifications to SWPPP necessary? Yes No If yes, describe: • The Town and EP are working together to update the mapping within the DPW facility and throughout the remainder of the town. The mapping updates throughout the town include retiring and/or combining BMP locations. Any other notes? • Minor amount of trash observed throughout the stormwater BMPs. • The Town continues to maintain their stormwater BMPs. BMP maintenance occurs bi-annually. The next scheduled maintenance is to occur this spring. The replaced riprap behind the salt shed continues to be in good condition. • The catch basins and proprietary separator BMPs (Hydro International) within the facility should be cleaned on an as needed basis and/or per the factory O&M manual. Per the Town, town-wide catch basin cleaning occurs once a year. • During the last inspection, the Town stated that the facility experienced moderate flooding during winter rain events. During the time of this inspection, no flooding was observed adjacent to the culvert that is north of the Offices. Minor amount of pooling was observed in some areas of the facility. • During previous inspections, a pipe was observed entering the catch basin in front of the Salt/Sand Shed, and flow was observed during dry weather. o In March 2023, EP spoke with a neighboring resident of the DPW, and they believed a stream was culverted and the pipe observed at the DPW could contain this stream water. The neighbor indicated that the stream may have been culverted years before the DPW was built. The Town should determine the source of this pipe, confirm that this pipe does convey this culverted stream, and update the stormwater mapping accordingly. • Salt was found eroding from the Salt/Sand Shed. Routine sweeping along the area is recommended. • The Town has purchased a vactor truck to aid in the cleaning of stormwater proprietary separator BMPs and other stormwater utilities. The vactor will be deployed and utilized within this fiscal year. • A stormwater sample was taken at the outfall north of the DPW and was observed as being clear with no obvious odors or floatables. Should the outfall be inundated with sediment or impeded by overgrown and dead vegetation, the Town should consider routinely maintaining the area. Currently, there is no immediate maintenance needed. Town of Lexington - DPW Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 1 of 10 Town of Lexington DPW Facility SWPPP Inspection Photos Vegetated swale, located behind the parking lot. Town of Lexington - DPW Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 2 of 10 DPW rain garden, located south of the DPW offices. Town of Lexington - DPW Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 3 of 10 The Manufactured System Infiltration Chamber, located adjacent to the DPW Building. Town of Lexington - DPW Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 4 of 10 Outlet located in the DPW facility (top photo, HDPE pipe). Inlet located in the DPW facility (bottom photo, RCP pipe). Town of Lexington - DPW Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 5 of 10 Salt/Sand Shed. Routine sweeping around the shed is recommended. Town of Lexington - DPW Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 6 of 10 Riprap at swale should be refreshed/replenished (top photo, located adjacent to the Minuteman bike path). Riprap should be refreshed/replenished where needed (bottom photo, located behind the Salt/Sand Shed). Town of Lexington - DPW Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 7 of 10 Brine solution tanks, located along the southeast wall of the DPW Building. Waste, plastic, and cardboard recycling dumpsters. Dumpster lids should be closed when not in use. Town of Lexington - DPW Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 8 of 10 Fueling Station, located west of the DPW Building. Pipe/hydrant/construction materials storage area. Town of Lexington - DPW Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 9 of 10 Vehicle Wash Bay and nearby catch basin. Town of Lexington - DPW Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 10 of 10 Outfall located north of the DPW. envpartners.com APPENDIX B Compost Facility Site Observation Report, Figure, and Photos Figure Exported: 11/13/2019 By: mroberts Using: \\woodardcurran.net\shared\Projects\0227871.05 Lexington MA - 2018-2019 MS4 Support\wip\GIS\Project Files\Compost_SWPPP_11x17_November2019.mxd") ") !( !( "!;Î"!;Î ;;;;;;;;;;;; ;;;CANOPIED MAINTENANCE SHED MATERIALS STORAGE(catch basin cleaning, cold patch, gravel, rubble, sand, street sweepings) COMPOST AREAS PARKING AREA OFFICE HAZARDOUS WASTE COLLECTION AREA ELECTRICALTRANSFORMER SEPTIC HOLDING TANK MATERIALS STORAGE(clean wood, metal,refrigerators) MATERIALS STORAGE(baseball dirt, gravel, playground mix, rip rap, sand) LOCATION OF STORMWATERDISCHARGE INTO WOODS LOCATION OF STORMWATERDISCHARGE INTO WOODS DA-1 DA-2 DA-3 F Ü 0 50 100 150 20025 Feet Legend Drainage Areas Outfall Lines ")Outfall Points !(Stormwater Discharge "!;Î BMP CITY OF LEXINGTON, MASWPPPCompost Facility Plan FIGURE # 3-2 DATE: NOVEMBER 2019 JOB NO.: 0227871.05 DOC: Compost_SWPPP_11x17_November2019.mxd DRAWN BY: MTR 1 " = 200 'SCALE: QUARTERLY SITE INSPECTION CHECKLIST Date: May 16, 2024 Time: 10:30-11:15 AM Inspector(s) Name(s): Karen Chan, Environmental Partners Inspector(s) Signature(s): Weather Conditions During Site Visit: Light rain (on and off), 60s Description of Any Discharge Occurring at the Time of the Inspection: Wet weather flow observed discharging into BMP and outfalls. Conduct a thorough inspection of the entire facility and grounds. Areas to Inspect Good Action Needed? (Routine) “Corrective Action”† Needed? Action Complete d? (Date) Potential Pollutant Sources: Description of problem: Parking Lots & Vehicle Traffic Areas Waste Collection (scrap metal) Compost Piles Catch Basin Cleanings & Street Sweepings Equipment Storage & Maintenance Areas Electric Transformers 400-Gallon Fuel Oil Tank Septic Tank Holding Area Earth Material Storage Area Yard/Storage Area General Facility Grounds & Outfall: Good Action Needed? (Routine) “Corrective Action”† Needed? Action Complete d? (Date) Inspect catch basins, outfall, gutters, compost piles, and stormwater infiltration areas for evidence of damage, erosion or any discharge of pollutants. Ensure that facility grounds show no signs of poor housekeeping (e.g., materials, residues, or trash that may come in contact with stormwater). Ensure there are no spots, pools, puddles, or other traces of oil, grease, or other chemicals on the ground around the facility, either liquid or solid. Ensure there is no evidence of offsite tracking of materials and no blowing of raw, final, or waste materials outside of the operational areas. Ensure there are no leaks or spills from equipment, drums or other containers, or containers in poor condition outside the facility. †Corrective Action” is triggered for systemic problems with control measures (e.g., if a dumpster lid is occasionally left open, this does not trigger “corrective action;” however, if a dumpster lid is missing or inoperable, this triggers corrective action. If an area needs routine sweeping, this does not trigger “corrective action;” however, if an area needs sweeping and is not being swept because supplies are not available or staff is not assigned, this triggers corrective action.) QUARTERLY SITE INSPECTION CHECKLIST Do any control measures need maintenance, repairs, or replacement? Yes* No If yes, describe: • Since the last inspection, the Town has installed rip rap along the entrance of the facility. With the new addition of the rip rap, the Town hopes the rip rap will be able to collect any sediment or wash out prior to discharging into the wetland. The Town is hoping to enhance the rip rap near term and add additional rip rap where needed. • The outlet across the facility office that is discharging into the wetlands should be routinely maintained and cleaned. Any rip rap that is missing should be replenished. A wet weather sample was taken at the mouth of the outlet and was observed as being light brown and clear. Similarly, the outfall behind the facility had a similar color. No obvious odors were observed at either locations. The Town should routinely maintain the outlets and outfalls. Any dead vegetation or sediment build-up should be removed to allow proper stormwater flow. Any additional control measures needed to comply with permit requirements? Yes* X No If yes, describe: Identification of any previously unidentified discharges from the Site: Yes* No If yes, describe: Describe any incidences of noncompliance observed (i.e., corrective action needed), summary of corrective actions taken and date initiated and completed (attach additional sheets if necessary): Are modifications to SWPPP necessary? Yes No If yes, describe: • The two catch basins on site are buried and no longer convey stormwater due to the regrading of the nearby road. The SWPPP should be updated to reflect these changes. The buried catch basins likely no longer need to be observed quarterly. Also, the Town should consider decommissioning the discharge point of the catch basins. Any other notes? • The outlet west of the hazardous waste collection should be routinely maintained. During the time of inspection, the debris and vegetation was cleared and the rip rap along the entrance of the facility had been added. A stormwater sample was taken at the mouth of the outlet and was observed as being light brown and clear, with no obvious odors. • Access to the outlet discharging into the woods, located in the southeast portion of the compost facility, was partially obstructed by construction debris and overgrown vegetation. Routine clearing is recommended to allow proper access. A stormwater sample was taken at the mouth of the outfall and was observed as being light brown and clear, with no obvious odors. • Empty oil drums were found in the hazardous waste collection area. If waste oil collection is collected and stored in the facility, it should be placed on a concrete palette, have proper signage, and include an accessible spill kit. Town of Lexington - Compost Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 1 of 9 Town of Lexington Compost Facility SWPPP Inspection Photos Compost storage area and covered propane tank storage area. Town of Lexington - Compost Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 2 of 9 Riprap installed at the beginning of the facility to aid in stormwater drainage and runoff. Town to continue to maintain and replenish riprap as needed. Town of Lexington - Compost Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 3 of 9 During the time of inspection, debris and vegetation were cleared and the riprap along the entrance of the facility had been added. A stormwater sample was taken at the mouth of the outlet and was observed as being light brown and clear, with no obvious odors. Town of Lexington - Compost Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 4 of 9 Various collection areas within cover hazardous waste collection area Town of Lexington - Compost Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 5 of 9 Canopied Maintenance Shed and covered hazardous waste collection area Town of Lexington - Compost Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 6 of 9 Oil drums were empty during inspection. If waste oil collection is collected and stored in the facility, it should be placed on a concrete palette, have proper signage, and include an accessible spill kit. Town of Lexington - Compost Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 7 of 9 Additional ponding observed around the composting areas. Town of Lexington - Compost Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 8 of 9 Additional stockpiles are located adjacent to the composting piles. Town of Lexington - Compost Facility May 16, 2024 Spring 2024 – SWPPP Inspection Environmental Partners Page 9 of 9 Access to the outlet discharging into the woods, located in the southeast portion of the compost facility, was partially obstructed by construction debris and overgrown vegetation. Routine clearing is recommended to allow proper access. A stormwater sample was taken at the mouth of the outfall and was observed as being light brown and clear, with no obvious odors.