HomeMy WebLinkAboutSWPPP Inspection Memo - Feb 2024
MEMORANDUM
February 22, 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
Winter 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 February 20, 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 dry 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 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.
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• Department of Public Works
o Minor amount of trash noticed throughout the stormwater BMPs.
o The Town should continue cutting back vegetation within its stormwater basins
periodically to ensure that the plant grown 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 previous inspections, a pipe was observed entering the catch basin in front of
the Salt 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 The mapping at the DPW Facility in PeopleGIS needs to be updated. Additional
structures including catch basins and inlet/outlets were observed in the field that are
not captured on PeopleGIS.
• The Compost Facility
o The Town should consider implementing a new stormwater management system to
better treat and manage stormwater. Initial corrective actions can consist of
implementing some short-term sediment and erosion control BMPs (e.g., silt sock,
berm, repositing the compost piles) to reduce sediment transport. Intermediate
actions can include the Town evaluating site drainage BMPs to improve the overall
stormwater management at the site.
o The outlet west of the hazardous waste collection area was partially blocked by
leaves and other debris. Additionally, the riprap pad in front of the outlet contained
leaves, brush, and sediment. These issues should be addressed to ensure the outlet
and riprap pad are functioning as designed.
o The outlet discharging into the woods, located in the southeast portion of the
compost facility, was covered in leaves and other debris, and could not be located.
These issues should be addressed to ensure the outlet and riprap pad are
functioning as designed.
o Empty oil drums were found in the hazardous waste collection area. If waste oil
collection is collected and stored in the facility, they should be placed on a concrete
palette, have proper signage, and include an accessible spill kit.
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 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.
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The next SWPPP site visit should be completed in the next quarter (between April and June 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 _________________________________________
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APPENDIX A
Department of Public Works
Site Observation Report, Figure, and Photos
DPW SWPPP QUARTERLY SITE OBSERVATION CHECKLIST
__________________Date: __________________ Time:
Inspector(s) Name(s):
Inspector(s) Signature(s): Weather Conditions During Site Visit:
Description of Any Discharge Occurring at the Time of the Site Visit:
Conduct a thorough observation of the entire facility and grounds
Areas to Observe
Potential Pollutant Sources:Description of problem:
Good Action
Needed?
(Routine)
“Corrective
ActionӠ
Needed?
Action
Completed?
(Date)
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
ActionӠ
Needed?
Action
Completed?
(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.)
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):
Karen Chan, Environmental Partners
N/A
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* No If yes, describe:
9:00-9:30 AMFebruary 20, 2024
Sunny, 30s
Are modifications to SWPPP necessary? Yes No If yes, describe:
DPW SWPPP QUARTERLY SITE OBSERVATION CHECKLIST
Any other notes?
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 winter rain events, the facility experienced moderate flooding. Staff determined that a culvert was
blocked, causing water to backup and flood. The Town cleared the blockage and will continue regular maintenance
on that culvert in the future.
Salt was found eroding from the salt/sand shed. Routine sweeping along the area is recommended.
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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:
Town of Lexington - DPW Facility February 20, 2024
Winter 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 February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 2 of 10
DPW rain garden located south of the DPW offices.
Town of Lexington - DPW Facility February 20, 2024
Winter 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 February 20, 2024
Winter 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 February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 5 of 10
Salt/sand shed. Routine sweeping around the shed is recommended.
Town of Lexington - DPW Facility February 20, 2024
Winter 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 behind the DPW’s salt shed continues to be working properly. Riprap should be refreshed/replenished
(bottom photo, located behind the salt shed)
Town of Lexington - DPW Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 7 of 10
Town of Lexington - DPW Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 8 of 10
Town of Lexington - DPW Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 9 of 10
Town of Lexington - DPW Facility February 20, 2024
Winter 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
QUARTERLY SITE INSPECTION CHECKLIST
Description of Any Discharge Occurring at the Time of the Inspection:
Conduct a thorough inspection of the entire facility and grounds.
Areas to Inspect
Potential Pollutant Sources:Description of problem:
Good Action
Needed?
(Routine)
“Corrective
ActionӠ
Needed?
Action
Completed?
(Date)
Parking Lots & Vehicle Traffic Areas
Waste Collection (scrap metal)
Compost Piles
Catch Basin Cleanings & Street SweepingsEquipment 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
ActionӠ
Needed?
Action
Completed?
(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 triggerscorrective 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.)Do any control measures need maintenance, repairs, or replacement? Yes* No If yes, describe:
Identification of any previously unidentified discharges from the Site: Yes* No If yes, describe:
Any additional control measures needed to comply with permit requirements? Yes* No If yes, describe:
Date: ____________________________________ Time:
Inspector(s) Name(s):
Inspector(s) Signature(s): Weather Conditions During Site Visit:
Karen Chan, Environmental Partners
February 20, 2024
Sunny, 30s
N/A
9:45-10:15 AM
The Compost Facility likely needs a new stormwater management system to better remove materials from the stormwater prior to discharging off the property. Initial corrective actions can consist of implementing some short-term sediment and erosion control BMPs (e.g.
silt sock, berm, rearrangement of compost pile locations) to reduce sediment transport. Intermediate actions can include the Town evaluating
site drainage BMPs to improve overall stormwater management at the site.
The outlet was partially covered by leaves and other debris, and the outlet's riprap pad contains debris/sediment. Both need maintenance
QUARTERLY SITE INSPECTION CHECKLIST
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: X
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 decomissioning
the discharge point of the catch basins.
Empty oil drums were found in the hazardous waste collection area. If waste oil collection is collected and stored in the facility, they should be placed on a concrete palette, have proper signage, and include an accessible spill kit.
*Any required modifications to control measures must be made before the next storm event if possible, or as soon as practicable.
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")
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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
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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:
Town of Lexington - Compost Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 1 of 10
Town of Lexington
Compost Facility SWPPP Inspection Photos
Town of Lexington - Compost Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 2 of 10
Town of Lexington - Compost Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 3 of 10
Ponding observed towards the end of the facility. Stormwater management recommended to aid in drainage.
Town of Lexington - Compost Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 4 of 10
Outlet is partially covered with debris and is recommended to be cleared with the assistance of the Highway
Department.
Town of Lexington - Compost Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 5 of 10
Empty propane tanks.
Town of Lexington - Compost Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 6 of 10
Electronics stockpiles.
Town of Lexington - Compost Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 7 of 10
Barrels were observed as being empty.
Town of Lexington - Compost Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 8 of 10
Oil drums were empty during inspection. If waste oil collection is collected and stored in the facility, they should
be placed on a concrete palette, have proper signage, and include an accessible spill kit.
Town of Lexington - Compost Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 9 of 10
Additional ponding observed around the composting areas.
Town of Lexington - Compost Facility February 20, 2024
Winter 2024 – SWPPP Inspection
Environmental Partners Page 10 of 10
Additional stock piles located adjacent to the composting piles.