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HomeMy WebLinkAboutPeer Review Response and Attachments August 28, 2024 Brittany DiRienzo Conservation Administrator Town of Yarmouth Conservation Commission Yarmouth Town Hall 1146 MA-28 South Yarmouth, MA 02664 RE: Response to Engineering Review Comments of 8/26/24 Stormwater Permit Application 770 Route 28 – South Yarmouth, MA ADE Project #3376.00 Dear Ms. DiRienzo: This response letter addresses the comments received on August 16, 2024 from Weston & Sampson, the peer review engineer regarding the Stormwater Permit Application for the project at 770 Route 28 in South Yarmouth, MA. Please note that the peer review engineers comments are italicized and our responses follow in bold text: Town of Yarmouth Conservation Commission Stormwater Management Regulations Compliance Review Section 2.04 Stormwater Management Site Plan: The applicant has submitted all of the items required for submission under this section, subject to the comments presented below. No Response Necessary Section 2.05 Stormwater Management Performance Standards 2.05(1) Low Impact Development Under this standard the applicant is required to “document in writing why LID strategies are not appropriate when not used to manage stormwater.” LID examples cited in this standard include infiltrating roof runoff at the source, planting large canopy trees over impervious areas and using porous paving materials, etc. where feasible. The applicant has provided a brief statement indicating that it is their belief that LID strategies have been implemented as much as feasible, and that such measures include the planting of as many grassed/landscaped areas as possible. We offer no objection to the rationale presented by the applicant, but the commission may wish for the applicant to further discuss what other Brittany DiRienzo, Conservation Administrator Town of Yarmouth Conservation Commission Response to Engineer Review Comments of 8/16/24 770 Route 28 – South Yarmouth, MA August 28, 2024 – Page 2 2 LID approaches may have been considered for this site. No Response Necessary 2.05(2) Good Housekeeping Procedures We have noted the following in our review related to this standard: • This standard requires provisions for car washing to occur “on lawns or pervious areas using biodegradable and phosphate free detergent.” This is not discussed in the O&M plan. We recommend that the engineer address the item noted above. The applicant intends to have all car washing take place at the abutting dealership. Car washing provisions have been added to the revised Long Term Stormwater O&M plan, revised dated 8/28/24 (attached). 2.05(3) Stormwater Management Systems Design We have noted the following in our review related to this standard: • The Engineer has shown that peak discharge rates do not exceed pre-development discharge rates forthe 2, 10, 25, 50 and 100-year 24-hour storm events. Runoff from all areas of onsite improvement discharge to either an above-ground stormwater basin or subsurface chambers. These retain runoff from stormwater events including the 50-year and 100-year event with no offsite runoff from these BMPs. These standards have been met. No Response Necessary • This section includes a standard requiring pretreatment of runoff from metal rooftops if the site is discharging to a Zone II or interim wellhead protection area. The Engineer is proposing to discharge roof runoff into the subsurface infiltration system with no pretreatment, but the site does not appear to be within the areas described above. This standard has been met. No Response Necessary • This standard requires the use of NOAA Atlas 14 rainfall data for stormwater modeling, or alternative datasets at the discretion of the commission. It appears that the Engineer has used NOAA Atlas 14 data in the analysis. This standard has been met. No Response Necessary Brittany DiRienzo, Conservation Administrator Town of Yarmouth Conservation Commission Response to Engineer Review Comments of 8/16/24 770 Route 28 – South Yarmouth, MA August 28, 2024 – Page 3 3 2.05(4) Stormwater Management System Pollutant Removal Requirements (new development) We have noted the following in our review related to this standard: • Under this standard, the engineer is given the option to provide a retention volume equal to or greater than one inch multiplied by the impervious area of the site. It is presumed that the engineer intends to meet this standard via the option for retaining the volume of runoff equivalent to or greater than 1-inch multiplied by the post-construction impervious surface, and this standard is likely met since the systems retain the 100-year storm event. That being said, a calculation of water quality flow was provided, but a calculation of static (i.e. not taking into account dynamic recharge) water quality volume (required vs proposed) was not found. We recommend that the Engineer provide this. A calculation sheet (Average Annual Pollutant Removal Calculation Sheet) showing that the proposed BMP storage exceeds the volume of runoff equivalent to 1-inch multiplied by the impervious area of the site was included in Appendix D of the original Stormwater Drainage Analysis dated June 21, 2024 submitted with the Stormwater Permit Application. 2.05(5) Stormwater Management System Pollutant Removal Requirements (redevelopment) This standard is not applicable since the site is a new development. No Response Necessary 2.05(6) Stormwater Management System EPA Tool Analysis We have noted the following in our review related to this standard: • The applicant has not used the EPA Region 1 BMP Accounting and Tracking Tool to evaluate average yearly pollutant removal for the BMPs. Under this standard, applicants are required to provide this analysis or are otherwise allowed to use other federal or state approved performance standards when the EPA tools are not applicable for the proposed BMPs. If the presumption stated under 2.05(4) is correct and the Engineer is using 1-inch of retention as a means of satisfying the nutrient removal standards, then the EPA Tool Analysis would not be required. We recommend that the Engineer clarify the approach being used. See Response to 2.05(4). Brittany DiRienzo, Conservation Administrator Town of Yarmouth Conservation Commission Response to Engineer Review Comments of 8/16/24 770 Route 28 – South Yarmouth, MA August 28, 2024 – Page 4 4 2.05(7) Discharges to water bodies subject to TMDL The site does not discharge to a water body subject to a TMDL. No Response Necessary Section 2.06 Erosion and Sediment Control Plan Standards 2.06(1) Contents of Erosion and Sediment Control Plan The applicant has submitted plans for Erosion and Sediment Control which are substantially complete, subject to further comments below. No Response Necessary 2.06(2) Stormwater Pollution Prevention Plan (SWPPP) Submission The project will disturb more than one acre of land, therefore it will be subject to coverage under the NPDES Construction General Permit. Under this section, the applicant is required to submit a complete copy of the SWPPP for the project. We recommend that the applicant submit a copy of the SWPPP. The commission may wish to consider adopting a condition of approval requiring the submission of the SWPPP prior to any ground disturbing activity since the contractor will ultimately be the party responsible for the SWPPP. The applicant will accept a condition that a SWPPP will be provided prior to the start of any ground disturbing activity. 2.06(3) Design of erosion and sediment controls The applicant’s erosion and sediment control plan substantially conforms to this standard. No Response Necessary 2.06(4) Erosion and Sedimentation Control Plan Content We have noted the following in our review related to this standard: • This standard calls for the inclusion of 100-year flood elevation information based on FEMA mapping, this was not found on the plan. The engineer should address this. The entirety of the site lies within a flood zone AE (El. 11). See general note #9 on sheets 2 or 3 of the site plans for more information. Also, see attached copy of the FEMA National Flood Hazard Layer FIRMette. Brittany DiRienzo, Conservation Administrator Town of Yarmouth Conservation Commission Response to Engineer Review Comments of 8/16/24 770 Route 28 – South Yarmouth, MA August 28, 2024 – Page 5 5 • This standard calls for a description of how fueling of vehicles/equipment and fuel/chemical storage will be conducted. This was not found on the plan. The engineer should address this. This has been addressed in notes 1 & 2 of the Construction Operation Notes on sheet 10 of the revised site plans dated 8/28/24. • This standard calls for the identification of “trees with a caliper twelve (12) inches diameter breast height or larger, noting specimen trees and forest communities.” This was not found in the submitted materials. We recommend that the applicant either clarify whether this is applicable, submit the applicable information, or request a waiver from the commission if that is the applicant’s intent. The applicant respectfully requests a waiver from the Commission for this item. • A description of procedures for construction vehicle fueling, temporary chemical storage and construction vehicle washing/washout was not found. The engineer should address this. This has been addressed in notes 1 & 2 of the Construction Operation Notes on sheet 10 of the revised site plans dated 8/28/24. 2.07 Operation and Maintenance (O&M) Plan 2.07(1) Stand-alone O&M plan requirements We have noted the following in our review related to this standard: • There are comments noted farther above that the applicant should address related to the O&M plan. • The O&M plan is currently formatted as a chapter within the stormwater report. The commission may wish to advise whether it is desirable to have it separated as a “stand-alone” report. The revised O&M Plan is now provided as a “stand-alone” report. See Attached. Massachusetts Stormwater Handbook Compliance Review Under Section 2.04(1) of the Yarmouth Conservation Commission Stormwater Management Regulations, the standards of the Massachusetts Stormwater Handbook are adopted by reference. These standards are listed below, followed by our review comments. Standard 1: Untreated Stormwater No new point discharges of untreated stormwater are proposed. The proposed stormwater improvements for the site include deep sump hooded catch basins, drain manholes, underground stormwater chambers, hydrodynamic separators and an infiltration basin. The design proposed Brittany DiRienzo, Conservation Administrator Town of Yarmouth Conservation Commission Response to Engineer Review Comments of 8/16/24 770 Route 28 – South Yarmouth, MA August 28, 2024 – Page 6 6 no new outfalls for stormwater to leave the site and proposes to retain stormwater up to and including the 100-year storm event. This standard has been met. No Response Necessary Standard 2: Post Development Peak Discharge Rates The stormwater report analyzed the site for storm events with recurrence intervals of 2-, 10-, 25-, 50- and 100- years. The analysis indicates that the post-redevelopment peak discharge rates will be less than existing condition peak discharge rates. This standard has been met, subject to comments under the heading of other standards below. No Response Necessary Standard 3: Recharge to Groundwater This standard requires that the site infiltration mimic preconstruction conditions for small storms based on the proposed increase in impervious area. The engineer has submitted calculations showing that onsite stormwater BMPs have been designed to retain and recharge far above the minimum required recharge volume. The Engineer has shown test pit data for the site, and adequate separation to groundwater appears to be provided for the subsurface infiltration system. The following issues were noted: • The test pit data for one of the test pits (TP-5) could not be found in the report, so adequate separation to seasonal high groundwater could not be confirmed. The test pit data for all test pits were included on sheet 5 of the site plans. The form 11 and 12 for test pit #5 is attached. • The subsurface chambers are called out as proprietary precast structures from Shea Concrete. While we are familiar with this product and the design appears to be consistent with the product, we would recommend that a detail/cross section for the chamber system should be in the plans for clarity. A detail for the “Shea 1,000 Gallon Drywall Infiltration System” was included on sheet 8 of the site plans. We recommend that the Engineer address the items above. Standard 4: Total Suspended Solids (TSS) Removal The town standards for TSS removal and stormwater quality treatment are more stringent than this standard. Compliance with the town’s standards is discussed in the preceding comments. We believe that this standard has been met. No Response Necessary Brittany DiRienzo, Conservation Administrator Town of Yarmouth Conservation Commission Response to Engineer Review Comments of 8/16/24 770 Route 28 – South Yarmouth, MA August 28, 2024 – Page 7 7 Standard 5: Land Uses with Higher Potential Pollutant Loads (LUHPPLs) The Engineer has indicated that the proposed development is not a LUHPPL. We agree with this assessment. No Response Necessary Standard 6: Protection of Critical Areas The applicant’s submission indicates that the site is not within a critical area. Even so, the proposed stormwater BMPs are in keeping with what is required under this standard. This standard has been addressed. No Response Necessary Standard 7: Redevelopments This project qualifies as a new development. The applicant is required to fully comply with these standards. This standard has been addressed. No Response Necessary Standard 8: Construction Period Pollution Prevention and Erosion/Sedimentation Control The engineer has provided an erosion and sedimentation control plan. Due to the fact that the site will disturb more than one acre, a Stormwater Pollution Prevention Plan (SWPPP) will be required to obtain coverage under the NPDES Construction General Permit. The town’s standards related to this are more stringent. Provided that the applicant addresses the preceding comments, this standard from the Handbook will be satisfied. No Response Necessary Standard 9: Operations & Maintenance Plan A long-term pollution prevention and operations and maintenance plan have been provided. Further comments that related to this standard are provided above under the analysis of the town’s similar standard. Provided that those comments are addressed, this standard from the Handbook will be satisfied. No Response Necessary Standard 10: Illicit Discharge Compliance Statement The Engineer has stated that an Illicit Discharge Compliance Statement will be signed by the responsible party prior to the start of construction. The Commission may wish to include this as a condition of approval for the project. The applicant will accept a condition that a signed Illicit Discharge Compliance Statement will be provided prior to construction. Brittany DiRienzo, Conservation Administrator Town of Yarmouth Conservation Commission Response to Engineer Review Comments of 8/16/24 770 Route 28 – South Yarmouth, MA August 28, 2024 – Page 8 8 If you have any questions, please do not hesitate to call me at (508) 888-9282. Sincerely, ATLANTIC DESIGN ENGINEERS, INC. Richard J. Tabaczynski, P.E. Vice President cc: Conserv Group, Inc. Mash Realty, LLC. Attachments: • FEMA National Flood Hazard Layer FIRMette • Form 11&12 for Test Pit #5 • Long Term Stormwater Operations and Maintenance Plan, revised dated 8/28/24 National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V, A99 With BFE or DepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas of less than one square mileZone X Future Conditions 1% Annual Chance Flood HazardZone X Area with Reduced Flood Risk due to Levee. See Notes.Zone X Area with Flood Risk due to LeveeZone D NO SCREEN Area of Minimal Flood Hazard Zone X Area of Undetermined Flood HazardZone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below. The basemap shown complies with FEMA's basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 8/29/2024 at 3:38 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Legend OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 8 B 20.2 The pin displayed on the map is an approximate point selected by the user and does not represent an authoritative property location. 1:6,000 70°13'26"W 41°39'18"N 70°12'49"W 41°38'51"N Basemap Imagery Source: USGS National Map 2023 Post-Construction Long Term Stormwater Operation & Maintenance Plan Proposed Cape and Islands Nissan Dealership South Yarmouth, MA Revised August 28, 2024 ADE Job #3376.00 A. GENERAL NOTES 1. Upon completion of construction, the operation and maintenance of all components of the stormwater management system will be the responsibility (financially and otherwise) of the system owner (responsible party): Mash Realty, LLC. 17 Old Main Street West Dennis, Massachusetts 02670 ________________________________ ___________________ Signature Date 2. The responsible party shall maintain a log of all operation and maintenance activities for the last three years including inspections, repair, replacement, and disposal. This log is to be made available to the Conservation Commission, Department of Municipal Inspections, and the Commonwealth of Massachusetts upon request. An annual certification is to be submitted on the first of November every year stating how non- structural and good housekeeping practices over the last 12 months adhered to the O&M plan. Once every five years, the certification must be prepared and signed by a registered Professional Engineer. The inspection certificate shall identify the date of inspection, name, and contact number of responsible party, specific structures inspected, specific maintenance and/or repairs required and general observations. Any deficiencies noted in the inspection report shall be corrected to the Conservation Commission’s, Department of Municipal Inspections, or Engineer’s satisfaction. 3. Disposal of accumulated sediment and hydrocarbons to be in accordance with the applicable local, state, and federal guidelines and regulations. Cape and Islands Nissan – South Yarmouth, MA Long-Term Stormwater Operation & Maintenance Plan Revised August 28, 2024 – Page 2 4. There shall be no illicit discharge of any waste or wastewater into the stormwater management system. The maintenance of the facility shall be undertaken in such a manner as to prevent any discharge of waste or wastewater into the stormwater management system. Any waste oil or other waste products generated during the maintenance shall be properly disposed of offsite in accordance with applicable local, state, and federal guidelines and regulations. Mash Realty, LLC. 17 Old Main Street West Dennis, Massachusetts 02670 ________________________________ ___________________ Signature Date 5. The Town of Yarmouth will be notified of changes in project ownership or assignment of operation and maintenance financial responsibility. 6. The maintenance schedule in this operation and maintenance (O&M) Plan will only be amended by mutual agreement of the Town of Yarmouth and the responsible party. Amendments will be made in writing and signed by the responsible party. 7. Vehicles are to be washed at the abutting dealership or at a commercial car wash. 8. The following restrictions on the applications of fertilizer shall be adhered to: i. Fertilizer shall not be applied during or immediately prior to heavy rainfall, such as but not limited to thunderstorms, hurricanes, or northeastern storms, or when the soil is saturated due to intense or extended rainfall; ii. Fertilizer shall not be applied between November 12 and the following March 31; iii. Fertilizer shall not be applied, spilled or deposited on impervious surfaces or in a manner that allows it to enter into storm drains; iv. Fertilizer shall not be applied within 100 feet of any surface water or within the Zone I of a public drinking water well; Cape and Islands Nissan – South Yarmouth, MA Long-Term Stormwater Operation & Maintenance Plan Revised August 28, 2024 – Page 3 v. Fertilizer containing phosphorus shall not be applied unless a soil test taken not more than three years before the proposed fertilizer application indicates that additional phosphorus is needed for growth of that turf, or unless establishing new turf or reestablishing or repairing turf after substantial damage or land disturbance; vi. A single application of fertilizer that contains nitrogen shall not exceed 1.0 pound of nitrogen per 1,000 square feet, shall consist of at least 20% slow-release nitrogen (SRN) fertilizer (NOTE: This represents the minimum percentage: use of higher SRN content is generally preferable, especially on sandy root zones, during stress and pre- stress periods, and when there are fewer annual applications of nitrogen made to a lawn) and the annual rate shall not exceed 3.2 pounds of actual nitrogen per thousand square feet. Single applications shall be done at intervals of no less than four weeks until the annual maximum is reached; vii. Grass clippings, leaves, or any other vegetative debris shall not be deposited into or within 50 feet of water bodies, retention and detention areas, drainage ditches or stormwater drains, or onto impervious surfaces, such as, but not limited to, roadways and sidewalks, except during scheduled cleanup programs. B. STORMWATER SYSTEM/BMPs AND SCHEDULED MAINTENANCE Erosion Control Barriers: Until the site is fully stabilized, erosion control barriers (sediment log, straw wattles, silt fence, etc.) should be inspected immediately after major storm events (2” or greater). Sediment deposits must be removed when the level of deposition reaches approximately one-half the height of the barrier. Repair/replace any sections of erosion control barriers that are damaged and install additional rows of barriers if needed. Deep Sump Hooded Catch Basin: Inspect after major storm events (2” or greater) for the first few months after construction and twice a year thereafter for clogged grates or pipes and for excessive accumulation of sediments and trash. Remove accumulation of leaves or debris over grate inlets as needed throughout the year. Clean sumps annually or when sediment reaches 24”, whichever occurs first. Cape and Islands Nissan – South Yarmouth, MA Long-Term Stormwater Operation & Maintenance Plan Revised August 28, 2024 – Page 4 Sub-Surface Infiltration System: Inspect after every major storm event (2” or greater) for the first few months after construction to ensure proper function. Thereafter, inspect at least twice per year during wet weather to ensure the system is draining properly. Check for accumulation of sediment and ponding water. If ponding water is visible inside the system for several days after a storm event, notify the engineer for possible remedial measures. Remove sediment while the system is dry, and at least every five years after construction. Note how long water remains standing in basin after a storm; standing water within the basin >72 hours after storm events should be immediately addressed. Street Sweeping: All paved areas should be swept two times per year, once during the late spring (after snowmelt) and once during the late fall (after leaf fall) seasons after construction. Infiltration Basin: At a minimum shall be inspected after every major storm event (>2 inches) for the first six (6) months, thereafter inspect twice a year at a minimum, for erosion, excessive accumulation of sediment and trash. Note how long water remains standing in basin after a storm; standing water within the basin >72 hours after storm events should be immediately addressed. Also, within the basin, check for signs of differential settlement, cracking, erosion, leakage in embankments, tree growth in embankments, condition of riprap, sediment accumulation and the health of the turf. Stormwater basins shall be mowed a minimum of twice per year. Grass clippings and accumulated organic matter should be removed from the basin to a non-sensitive area. Repairs and reseeding should be done as required. Sediment and debris should be removed manually when stormwater basin is thoroughly dry, a minimum of once per year or when the sediment level reaches a depth of three inches (3”) in the basin or half an inch (1/2”) in the low flow drain. Outlet Pipes and Flared End Sections: Inspect after every major storm event (>2 inches) for the first few months after construction to ensure proper stabilization and function, thereafter inspect twice a year for erosion, clogging, settling, and excessive accumulation of leaves, trash, debris or sediment and channelization of stormwater discharge. Rip-Rap Aprons Inspect after every major storm event (>2 inches) for the first few months after construction to ensure proper stabilization and function, thereafter inspect twice per Cape and Islands Nissan – South Yarmouth, MA Long-Term Stormwater Operation & Maintenance Plan Revised August 28, 2024 – Page 5 year at a minimum, for erosion, excessive accumulation of sediment and trash. Repair eroded spots immediately after inspection. Accumulated sediment shall be removed at least once a year or before it exceeds 0.5' in depth, whichever occurs first. Sediment shall be disposed of in a suitable area and protected from erosion by either structural or vegetative means. Inspect rip-rap aprons for signs of excess sediment or signs of failure. First defense FD-4HC stormwater separator: Perform all operation and maintenance as recommended by the manufacturers, at a minimum to include the following: inspect quarterly for the first year of installation and every 6 months thereafter. Sediment, oil and floatables should be removed once per year or following a spill in the drainage area. C. ESTIMATED ANNUAL BUDGET The estimated annual budget for the activities required in this Long-Term Stormwater Operation and Maintenance Plan is $2,000.00. D. SAMPLE OPERATION AND MAINTENANCE LOG (Next Page) Cape and Islands Nissan – South Yarmouth, MA Long-Term Stormwater Operation & Maintenance Plan Revised August 28, 2024 – Page 6 SAMPLE OPERATION AND MAINTENANCE LOG CAPE AND ISLANDS NISSAN SOUTH YARMOUTH, MASSACHUSETTS LONG TERM STORMWATER OPERATION & MAINTENANCE PLAN Date: _______________________ Personnel Present: _____________________________ _____________________________________________________________________________ Inspectors Name: _______________________________________ Inspectors Contact Information: _______________________________________ _______________________________________ _______________________________________ Signature: _______________________________________ O&M ITEM: COMMENTS, CORRECTIVE ACTION NEEDED, AND NOTES: Erosion Control Barriers Deep Sump Hooded Catch Basin Sub-Surface Infiltration System First Defense Unit Street Sweeping Infiltration Basin Outlet Pipes and Flared End Sections Rip-Rap Aprons