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HomeMy WebLinkAbout2024-03-20 Stormwater ReportPrepared by: 349 Main Street – Route 28 West Yarmouth, MA 02673 STORMWATER REPORT MULTI-FAMILY RESIDENTIAL 811 ROUTE 28 SOUTH YARMOUTH, MA MARCH 2024 Owner/Applicant: CHRISTINA MEGGISON 693 Russells Mill Road South Dartmouth, MA 02748 BSC Job Number: 50646.00 Stormwater Report Multi-Family Residential South Yarmouth, MA TABLE OF CONTENTS 1.0 PROJECT INFORMATION 1.01 PROJECT DESCRIPTION 1.02 PRE-DEVELOPMENT CONDITIONS 1.03 POST-DEVELOPMENT CONDITIONS 2.0 DRAINAGE SUMMARY 2.01 STORMWATER STANDARD 1 – NEW STORMWATER CONVEYANCES 2.02 STORMWATER STANDARD 2 – STORMWATER RUNOFF RATES 2.03 STORMWATER STANDARD 3 – GROUNDWATER RECHARGE 2.04 STORMWATER STANDARD 4 – TSS REMOVAL 2.05 STORMWATER STANDARD 5 – LUHPPL 2.06 STORMWATER STANDARD 6 – CRITICAL AREAS 2.07 STORMWATER STANDARD 7 – REDEVELOPMENT PROJECTS 2.08 STORMWATER STANDARD 8 – SEDIMENTATION & EROSION CONTROL PLAN 2.09 STORMWATER STANDARD 9 – LONG TERM O&M PLAN 2.10 STORMWATER STANDARD 10 – ILLICIT DISCHARGES 2.11 CONCLUSIONS 2.12 COMPENSATORY FLOOD STORAGE 3.0 CONSTRUCTION PERIOD POLLUTION PREVENTION AND EROSION AND SEDIMENTATION CONTROL 4.0 LONG-TERM POLLUTION PREVENTION & OPERATION AND MAINTENANCE PLAN 5.0 HYDROLOGY CALCULATIONS 5.01 EXISTING WATERSHED PLAN 5.02 EXISTING HYDROLOGY CALCULATIONS (HYDROCAD™ PRINTOUTS) 5.03 PROPOSED WATERSHED PLAN 5.04 PROPOSED HYDROLOGY CALCULATIONS (HYDROCAD™ PRINTOUTS) 6.0 ADDITIONAL DRAINAGE CALCULATIONS 6.01 TSS REMOVAL CALCULATIONS 6.02 GROUNDWATER RECHARGE VOLUME CALCULATIONS 6.03 WATER QUALITY VOLUME CALCULATIONS 6.04 ILLICIT DISCHARGE COMPLIANCE STATEMENT APPENDICES APPENDIX A – USGS LOCUS MAP APPENDIX B – FEMA MAP APPENDIX C – WEB SOIL SURVEY Stormwater Report Multi-Family Residential South Yarmouth, MA SECTION 1.0 PROJECT INFORMATION Stormwater Report Multi-Family Residential South Yarmouth, MA 1.01 PROJECT DESCRIPTION Christina Meggison (The Applicant) is seeking to construct a multi-family housing development in South Yarmouth, Massachusetts, hereinafter referred to as “the Project.” The total property area is approximately 0.59 acres and is located off Massachusetts Route 28. The project is bounded on the north by Route 28, on the east and the south by residential properties, and bound on the west by a small business. The Project consists of the clearing and grubbing of the southwest section of the property and construction of a 2-story residential building with of 8-units, one bedroom per unit, as well as surface parking, walkways, utility services, a septic system, and stormwater management systems. The building has a footprint of approximately 4,448 square feet. 1.02 PRE-DEVELOPMENT CONDITIONS The existing site topography generally slopes southwest across the property towards the depressions west of the existing building with slopes ranging from 0-16%. The current site is comprised of a gravel driveway leading toward a small one-story dwelling and the primary soil classification identified by the NRCS Web Soil Survey is Carver coarse sand 252A), which accounts for all of the project area. On November 29, 2023, BSC Group conducted five test pits on the site, the locations of which are noted on the Grading and Drainage plan. The test pits consisted primarily of sand to a depth of 3 feet generally conforming with the soils mapping. Based on the materials found, runoff calculations have been performed using curve numbers corresponding to Hydrologic Soil Group (HSG) A. The existing site has no existing drainage facilities, and the majority of the stormwater runoff is directed to the depression on the property. A small portion of the site discharges off-site to the north to Route 28 and to the south towards the wooded area. 1.03 POST-DEVELOPMENT CONDITIONS The proposed stormwater management systems have been designed in a manner that will meet or exceed the provisions of the Department of Environmental Protection (DEP) Stormwater Management Standards for a new construction project. Stormwater runoff from the entirety of the 2-story building (approximately 4,448 square-feet) will be collected by a series of roof drains and will be released at controlled rates to an underground infiltration system to the east of the proposed building. Stormwater runoff from the site driveway and small parking area at the main entrance to the building will be collected via two deep sump catch basins before being directed to another underground infiltration system to the west of the proposed building. Stormwater runoff from the lawn area in the eastern portion of the site will be collected via a bioretention area. The implementation of the infiltration systems and the bioretentiona rea result in no onsite flow to catchment area 1R in post-development conditions, as shown in the hydrology calculations in Section 5.0. These underground infiltration systems provide recharge to groundwater and provides peak flow rate attenuation. Each system is designated to completely hold and infiltrate the 100-year, 24-hour storm event. Since all soils sampled in the five test pits were identified as sand, the infiltration rate for sand (8.27-inches per hour) has been used in the infiltration system and basin design to account for the materials found. Based upon the test pit data performed in November 2023, the estimated seasonal high groundwater elevation was observed at three of the five test pits, with elevations ranging between elevation 0.2 and 0.7. As such the infiltration systems all provide a minimum 4- feet clearance above groundwater. Specifics of the project’s compliance with the Stormwater Standards are discussed in detail in the following sections. Stormwater Report Multi-Family Residential South Yarmouth, MA SECTION 2.0 DRAINAGE SUMMARY Stormwater Report Multi-Family Residential South Yarmouth, MA 2.01 Stormwater Standard 1 – New Stormwater Conveyances Per Massachusetts Stormwater Management Standard #1, no new outfalls may discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. No new untreated stormwater discharges are proposed. 2.02 Stormwater Standard 2 – Stormwater Runoff Rates Watershed modeling was performed using HydroCAD Stormwater Modeling Software version 10.00, a computer aided design program that combines SCS runoff methodology with standard hydraulic calculations. A model of the site’s hydrology was developed for both pre- and post-development conditions to assess the effects of the proposed development on the project site and surrounding areas. Storm Frequency NOAA 14 Rainfall (Inches) 2-year 3.36 10-year 4.89 25-year 5.85 50-year 6.57 100-year 7.32 The stormwater management system for the project has been designed such that the post-development conditions result in no increase to peak runoff rates off the property for the 2, 10, 25, 50, and 100-year, 24-hour storm events, as detailed in the table below. Peak Flow Discharge Rates Node 1R – On-Site Storm Event Pre-Development Peak Discharge Rate (cfs) Post-Development Peak Discharge Rate (cfs) Change in Peak Discharge Rate (cfs) 2-Year 0.32 0.0 -0.32 10-Year 0.97 0.0 -0.97 25-Year 1.45 0.0 -1.45 50-Year 1.83 0.0 -1.83 100-Year 2.25 0.0 -2.25 Stormwater Report Multi-Family Residential South Yarmouth, MA Node 2R – Flow Towards Route 28 Storm Event Pre-Development Peak Discharge Rate (cfs) Post-Development Peak Discharge Rate (cfs) Change in Peak Discharge Rate (cfs) 2-Year 0.08 0.02 -0.06 10-Year 0.15 0.05 -0.10 25-Year 0.19 0.07 -0.12 50-Year 0.23 0.09 -0.14 100-Year 0.26 0.11 -0.15 Node 3R – Flow Off-Site (South) Storm Event Pre-Development Peak Discharge Rate (cfs) Post-Development Peak Discharge Rate (cfs) Change in Peak Discharge Rate (cfs) 2-Year 0.00 0.00 0.0 10-Year 0.00 0.00 0.0 25-Year 0.01 0.00 -0.01 50-Year 0.02 0.01 -0.01 100-Year 0.02 0.01 -0.01 2.03 Stormwater Standard 3 – Groundwater Recharge Groundwater recharge is provided on site via two underground structural infiltration systems beneath the surface parking area to the north of the building and east of the building. Overall, the project will result in no loss of annual recharge to groundwater as required by Standard 3. Refer to Section 6.0 of this Report for groundwater recharge information. 2.04 Stormwater Standard 4 – TSS Removal As a new development, the Project stormwater management system will achieve a TSS removal greater than 80%. The proposed stormwater management systems have been designed to provide treatment of runoff in order to reduce suspended solids prior to discharge off-site through the implementation of the following best management practices: Deep Sump Hooded Catch Basins Underground Stormwater Infiltration Systems The water quality volume is defined as the runoff volume requiring TSS Removal for the site and is equal to 0.5-inches of runoff over the total impervious area of the post-development site. The required water quality volume for the project is provided in Section 6.0 of this Report. The underground infiltration systems have been sized to treat the required water quality volume and calculations are included in Section 6.0 of this Report. A long-term pollution prevention plan complying with the requirements of Standard 4 is included in Section 4.0 of this Report. Stormwater Report Multi-Family Residential South Yarmouth, MA 2.05 Stormwater Standard 5 – Land Uses with Higher Potential Pollutant Loads This standard is not applicable as the project site is not a land use with higher potential pollutant loads (LUHPPL). 2.06 Stormwater Standard 6 – Stormwater Discharges to a Critical Area This standard is not applicable as runoff from the project site does not discharge to a critical area. 2.07 Stormwater Standard 7 – Redevelopment Projects This project is a new development and therefore has been designed to comply fully with the Stormwater Management Standards. 2.08 Stormwater Standard 8 – Sedimentation and Erosion Control Plan Erosion and sedimentation controls are shown on the Project Plans. Additionally, a Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan is included in Section 3.0 of this Report. 2.09 Stormwater Standard 9 – Long Term Operation and Maintenance Plan A Long-Term Operation and Maintenance Plan is included in Section 4.0 of this Report. 2.10 Stormwater Standard 10 – Illicit Discharges There are no known illicit discharges on the project site and none are proposed. An illicit discharge compliance statement is included in Section 6.0 and will be signed by the Applicant prior to issuance of any permits. 2.11 Conclusion The project has been designed in accordance with DEP Stormwater Management Standards and the Town of Yarmouth Stormwater Management Regulations. Through the construction of the aforementioned stormwater systems, the project will provide peak rate attenuation, TSS removal and groundwater recharge. SECTION 3.0 CONSTRUCTION PERIOD POLLUTION PREVENTION AND EROSION AND SEDIMENTATION CONTROL PLAN Stormwater Report 811 Route 28 South Yarmouth, MA 3.0 CONSTRUCTION PERIOD POLLUTION PREVENTION AND EROSION AND SEDIMENTATION CONTROL PLAN This Section specifies requirements and suggestions for implementation of a Stormwater Pollution Prevention Plan (SWPPP) for 811 Route 28, in South Yarmouth, Massachusetts. The SWPPP shall be provided and maintained on-site by the Contractor(s) during all construction activities. The SWPPP shall be updated as required to reflect changes to construction activity. The stormwater pollution prevention measures contained in the SWPPP shall be at least the minimum required by Local Regulations. The Contractor shall provide additional measures to prevent pollution from stormwater discharges in compliance with the National Pollution Discharge Elimination System (NPDES) Phase II permit requirements and all other local, state and federal requirements. The SWPPP shall include provisions for, but not be limited to, the following: 1. Construction Trailers 2. Lay-down Areas 3. Equipment Storage Areas 4. Stockpile Areas 5. Disturbed Areas The Contractor shall NOT begin construction without submitting evidence that a NPDES Notice of Intent NOI) governing the discharge of stormwater from the construction site for the entire construction period has been filed at least fourteen (14) days prior to construction. It is the Contractor's responsibility to complete and file the NOI, unless otherwise determined by the project team. The cost of any fines, construction delays and remedial actions resulting from the Contractor's failure to comply with all provisions of local regulations and Federal NPDES permit requirements shall be paid for by the Contractor at no additional cost to the Owner. As a requirement of the EPA’s NPDES permitting program, each Contractor and Subcontractor responsible for implementing and maintaining stormwater Best Management Practices shall execute a Contractor's Certification form. Erosion and Sedimentation Control The Contractor shall be solely responsible for erosion and sedimentation control at the site. The Contractor shall utilize a system of operations and all necessary erosion and sedimentation control measures, even if not specified herein or elsewhere, to minimize erosion damage at the site to prevent the migration of sediment into environmentally sensitive areas. Environmentally sensitive areas include all wetland resource areas within, and downstream of, the site, and those areas of the site that are not being altered. Erosion and sedimentation control shall be in accordance with this Section, the design drawings, and the following: National Pollutant Discharge Elimination System General Permit for Discharges from Construction Activities (EPA Construction General Permit February 16, 2017). Massachusetts Stormwater Management Policy Handbook issued by the Massachusetts Department of Environmental Protection, January 2008. Massachusetts Erosion and Sediment Control Guidelines for Urban and Suburban Areas, A Guide for Planners, Designers and Municipal Officials, March 1997. The BMP's presented herein should be used as a guide for erosion and sedimentation control and are not intended to be considered specifications for construction. The most important BMP is maintaining a rapid construction process, resulting in prompt stabilization of surfaces, thereby reducing erosion potential. Stormwater Report 811 Route 28 South Yarmouth, MA Given the primacy of rapid construction, these guidelines have been designed to allow construction to progress with essentially no hindrance by the erosion control methods prescribed. These guidelines have also been designed with sufficient flexibility to allow the Contractor to modify the suggested methods as required to suit seasonal, atmospheric, and site-specific physical constraints. Another important BMP is the prevention of concentrated water flow. Sheet flow does not have the erosive potential of a concentrated rivulet. These guidelines recommend construction methods that allow localized erosion control and a system of construction, which inhibits the development of shallow concentrated flow. These BMP's shall be maintained throughout the construction process. CONTACT INFORMATION AND RESPONSIBLE PARTIES The following is a list of all project-associated parties: Owner Christina Meggison 693 Russells Mill Road South Dartmouth, MA 02748 Contractor To be determined Environmental Consultant BSC Group, Inc. 349 Main Street – Route 28 West Yarmouth, MA 02673 Contact: Brian Yergatian, P.E. Phone: (617) 896–4590 Email: byergation@bscgroup.com Qualified SWPPP Inspectors To Be Determined 3.1 Procedural Conditions of the Construction General Permit (CGP) The following list outlines the Stormwater Responsibilities for all construction operators working on the Project. The operators below agree through a cooperative agreement to abide by the following conditions throughout the duration of the construction project, effective the date of signature of the required SWPPP. These conditions apply to all operators on the project site. The project is subject to EPA’s NPDES General Permit through the CGP. The goal of this permit is to prevent the discharge of pollutants associated with construction activity from entering the existing and proposed storm drain system or surface waters. All contractors/operators involved in clearing, grading and excavation construction activities must sign the appropriate certification statement required, which will remain with the SWPPP. The owner must also sign a certification, which is to remain with the SWPPP in accordance with the signatory requirements of the SWPPP. Stormwater Report 811 Route 28 South Yarmouth, MA Once the SWPPP is finalized, a signed copy, plus supporting documents, must be held at the project site during construction. A copy must remain available to EPA, State and Local agencies, and other interested parties during normal business hours. The SWPPP will be kept at the construction site until final stabilization has been achieved and will be available for review upon request. Project specific SWPPP documents are not submitted to the US EPA unless the agency specifically requests a copy for review. SWPPP documents requested by a permitting authority, the permitee(s) will submit it in a timely manner. EPA inspectors will be allowed free and unrestricted access to the project site and all related documentation and records kept under the conditions of the permit. The permitee is expected to keep all BMP’s and Stormwater controls operating correctly and maintained regularly. Any additions to the project which will significantly change the anticipated discharges of pollutants, must be reported to the EPA. The EPA should also be notified in advance of any anticipated events of noncompliance. The permitee must also orally inform the EPA of any discharge, which may endanger health or the environment within 24 hours, with a written report following within 5 days. In maintaining the SWPPP, all records and supporting documents will be compiled together in an orderly fashion. Inspection reports and amendments to the SWPPP must remain with the document. Federal regulations require permitee(s) to keep their Project Specific SWPPP and all reports and documents for at least three (3) years after the project is complete. 3.2 Existing Site and Soil Conditions The existing site topography generally slopes southwest across the property towards the depressions west of the existing building with slopes ranging from 0-16%. The current site is comprised of a gravel driveway leading toward a small one-story dwelling and the primary soil classification identified by the NRCS Web Soil Survey is Carver coarse sand (252A), which accounts for all of the project area. On November 29, 2023, BSC Group conducted five test pits on the site, the locations of which are noted on the Grading and Drainage plan. The test pits consisted primarily of sand to a depth of 3 feet generally conforming with the soils mapping. Based on the materials found, runoff calculations have been performed using curve numbers corresponding to Hydrologic Soil Group (HSG) A. The existing site has no existing drainage facilities, and the majority of the stormwater runoff is directed to the depression on the property. A small portion of the site discharges off-site to the north to Route 28 and to the south towards the wooded area. 3.3 Project Description and Intended Construction Sequence The site is currently comprised of a gravel driveway leading to a one-story dwelling. The proposed activities will include the following major components: The construction of one (1) multi-family housing building with associated parking, driveways, and walkways, The construction of stormwater management systems, The construction of a septic system, Site grading, and Utility connections and installation. The proposed project will disturb a total of approximately 25,499± S.F. (0.58± acres). Stormwater Report 811 Route 28 South Yarmouth, MA Soil disturbing activities will include site demolition, installing stabilized construction exits, installation of erosion and sedimentation controls, grading, storm drain inlets, stormwater management systems, utilities, building foundation, construction of site driveways and preparation for final landscaping. Please refer to Table 1 for the projects anticipated construction timetable. A description of BMP’s associated with project timetable and construction-phasing elements is provided in this Erosion and Sediment Control Plan. Table 1 – Anticipated Construction Timetable Construction Phasing Activity Anticipated Timetable Grubbing and Stripping of Limits of Construction Phase To be determined Rough Site Grading and Site Utilities To be determined Utility Plan Construction To be determined Landscaping To be determined 3.4 Potential Sources of Pollution Any project site activities that have the potential to add pollutants to runoff are subject to the requirements of the SWPPP. Listed below are a description of potential sources of pollution from both sedimentation to Stormwater runoff, and pollutants from sources other than sedimentation. Table 2 – Potential Sources of Sediment to Stormwater Runoff Potential Source Activities/Comments Construction Site Entrance and Site Vehicles Vehicles leaving the site can track soils onto public roadways. Site Vehicles can readily transport exposed soils throughout the site and off-site areas. Grading Operations Exposed soils have the potential for erosion and discharge of sediment to off-site areas. Material Excavation, Relocation, and Stockpiling Stockpiling of materials during excavation and relocation of soils can contribute to erosion and sedimentation. In addition, fugitive dust from stockpiled material, vehicle transport and site grading can be deposited in wetlands and waterway. Landscaping Operations Landscaping operations specifically associated with exposed soils can contribute to erosion and sedimentation. Hydroseeding, if not properly applied, can runoff to adjacent wetlands and waterways. Table 3 – Potential Pollutants and Sources, other than Sediment to Stormwater Runoff Potential Source Activities/Comments Staging Areas and Construction Vehicles Vehicle refueling, minor equipment maintenance, sanitary facilities and hazardous waste storage Materials Storage Area General building materials, solvents, adhesives, paving materials, paints, aggregates, trash, etc. Construction Activities Construction, paving, curb/gutter installation, concrete pouring/mortar/stucco 3.5 Erosion and Sedimentation Control Best Management Practices All construction activities will implement Best Management Practices (BMP’s) in order to minimize overall site disturbance and impacts to the sites natural features. Please refer to the following sections for a detailed Stormwater Report 811 Route 28 South Yarmouth, MA description of site specific BMP’s. In addition, an Erosion and Sedimentation Control Plan is provided in the Site Plans. 3.6 Timetable and Construction Phasing This section provides the Owner and Contractor with a suggested order of construction that shall minimize erosion and the transport of sediments. The individual objectives of the construction techniques described herein shall be considered an integral component of the project design intent of each project phase. The construction sequence is not intended to prescribe definitive construction methods and should not be interpreted as a construction specification document. However, the Contractor shall follow the general construction phase principles provided below: Protect and maintain existing vegetation wherever possible. Minimize the area of disturbance. To the extent possible, route unpolluted flows around disturbed areas. Install mitigation devices as early as possible. Minimize the time disturbed areas are left unstabilized. Maintain siltation control devices in proper condition. The contractor should use the suggested sequence and techniques as a general guide and modify the suggested methods and procedures as required to best suit seasonal, atmospheric, and site specific physical constraints for the purpose of minimizing the environmental impact of construction. Demolition, Grubbing and Stripping of Limits of Construction Phase Install Temporary Erosion Control (TEC) devices as required to prevent sediment transport into resource areas. Place a ring of silt socks and/or haybales around stockpiles. Stabilize all exposed surfaces that will not be under immediate construction. Store and/or dispose all pavement and building demolition debris as indicated in accordance with all applicable local, state, and federal regulations. Driveway Area Sub-Base Construction Install temporary culverts and diversion ditches and additional TEC devices as required by individual construction area constraints to direct potential runoff toward detention areas designated for the current construction phase. Compact gravel as work progresses to control erosion potential. Apply water to control air suspension of dust. Avoid creating an erosive condition due to over-watering. Install piped utility systems as required as work progresses, keeping all inlets sealed until all downstream drainage system components are functional. Binder Construction Fine grade gravel base and install processed gravel to the design grades. Compact pavement base as work progresses. Install pavement binder coat starting from the downhill end of the site and work toward the top. Finish Paving Repair and stabilize damaged side slopes. Clean inverts of drainage structures. Install final top coat of pavement. Stormwater Report 811 Route 28 South Yarmouth, MA Final Clean-up Clean inverts of culverts and catch basins. Remove sediment and debris from rip-rap outlet areas. Remove TEC devices only after permanent vegetation and erosion control has been fully established. 3.7 Site Stabilization Grubbing Stripping and Grading Erosion control devices shall be in place as shown on the design plans before grading commences. Stripping shall be done in a manner, which will not concentrate runoff. If precipitation is expected, earthen berms shall be constructed around the area being stripped, with a silt sock, silt fence or haybale dike situated in an arc at the low point of the berm. If intense precipitation is anticipated, silt socks, haybales, dikes and /or silt fences shall be used as required to prevent erosion and sediment transport. The materials required shall be stored on site at all time. If water is required for soil compaction, it shall be added in a uniform manner that does not allow excess water to flow off the area being compacted. Dust shall be held at a minimum by sprinkling exposed soil with an appropriate amount of water. Maintenance of Disturbed Surfaces Runoff shall be diverted from disturbed side slopes in both cut and fill. Mulching may be used for temporary stabilization. Silt sock, haybale or silt fences shall be set where required to trap products of erosion and shall be maintained on a continuing basis during the construction process. Loaming and Seeding Loam shall not be placed unless it is to be seeded directly thereafter. All disturbed areas shall have a minimum of 4” of loam placed before seeded and mulched. Consideration shall be given to hydro-mulching, especially on slopes in excess of 3 to 1. Loamed and seeded slopes shall be protected from washout by mulching or other acceptable slope protection until vegetation begins to grow. Stormwater Collection System Installation The Stormwater drainage system shall be installed from the downstream end up and in a manner which will not allow runoff from disturbed areas to enter pipes. Excavation for the drainage system shall not be left open when rainfall is expected overnight. If left open under other circumstances, pipe ends shall be closed by a staked board or by an equivalent method. All catch basin openings shall be covered by a silt bag between the grate and the frame or protected from sediment by silt fence surrounding the catch basin grate. Completion of Paved Areas During the placement of sub-base and pavement, the entrance to the Stormwater drainage systems shall be sealed when rain is expected. When these entrances are closed, consideration must be given to the direction of run-off and measures shall be undertaken to minimize erosion and to provide for the collection of sediment. In some situations, it may be necessary to keep catch basins open. Appropriate arrangements shall be made downstream to remove all sediment deposition. Stormwater Report 811 Route 28 South Yarmouth, MA Stabilization of Surfaces Stabilization of surfaces includes the placement of pavement, rip-rap, wood bark mulch and the establishment of vegetated surfaces. Upon completion of construction, all surfaces shall be stabilized even though it is apparent that future construction efforts will cause their disturbance. Vegetated cover shall be established during the proper growing season and shall be enhanced by soil adjustment for proper pH, nutrients and moisture content. Surfaces that are disturbed by erosion processes or vandalism shall be stabilized as soon as possible. Areas where construction activities have permanently or temporarily ceased shall be stabilized within 14 days from the last construction activity, except when construction activity will resume within 21 days (e.g., the total time period that construction activity is temporarily ceased is less than 21 days). Hydro-mulching of grass surfaces is recommended, especially if seeding of the surfaces is required outside the normal growing season. Hay mulch is an effective method of temporarily stabilizing surfaces, but only if it is properly secured by branches, weighted snow fences or weighted chicken wire. 3.8 Temporary Structural Erosion Control Measures Temporary erosion control measures serve to minimize construction-associated impacts to wetland resource and undisturbed areas. Please refer to the following sections for a description of temporary erosion control measures implemented as part of the project and this sample SWPPP. 3.8.1 Silt Socks, Haybales, and Silt Fencing The siltation barriers will demarcate the limit of work, form a work envelope and provide additional assurance that construction equipment will not enter the adjacent wetlands or undisturbed portions of the site. All barriers will remain in place until disturbed areas are stabilized. 3.8.2 Temporary Stormwater Diversion Swale A temporary diversion swale is an effective practice for temporarily diverting stormwater flows and to reduce stormwater runoff velocities during storm events. The swale channel can be installed before infrastructure construction begins at the site, or as needed throughout the construction process. The diversion swale should be routinely compacted or seeded to minimize the amount of exposed soil. 3.8.3 Dewatering Basins Dewatering may be required during stormwater system, foundation construction and utility installation. Should the need for dewatering arise, groundwater will be pumped directly into a temporary settling basin, which will act as a sediment trap during construction. All temporary settling basins will be located within close proximity of daily work activities. Prior to discharge, all groundwater will be treated by means of the settling basin or acceptable substitute. Discharges from sediment basins will be free of visible floating, suspended and settleable solids that would impair the functions of a wetland or degrade the chemical composition of the wetland resource area receiving ground or surface water flows and will be to the combined system. 3.8.4 Material Stockpiling Locations Piping and trench excavate associated with the subsurface utility work will be contained with a single row of silt socks and/or haybales. Stormwater Report 811 Route 28 South Yarmouth, MA 3.9 Permanent Structural Erosion Control Measures Permanent erosion control measures serve to minimize post-construction impacts to wetland resource areas and undisturbed areas. Please refer to the Site Plans and Long-Term Operations and Maintenance Plan for a description of permanent erosion control measures implemented as part of the project and this SWPPP. 3.10 Good Housekeeping Best Management Practices 3.10.1 Street Sweeping Route 28 in front of the project property shall be swept clean on a daily basis of any soils tracked onto it from the project site. All sweepings shall be disposed of off-site in accordance with all applicable laws and regulations. 3.10.2 Material Handling and Waste Management Solid waste generation during the construction period will be primarily construction debris. The debris will include scrap lumber (used forming and shoring pallets and other shipping containers), waste packaging materials (plastic sheeting and cardboard), scrap cable and wire, roll-off containers (or dumpsters) and will be removed by a contract hauler to a properly licensed landfill. The roll-off containers will be covered with a properly secured tarp before the hauler exits the site. In addition to construction debris, the construction work force will generate some amount of household-type wastes (food packing, soft drink containers, and other paper). Trash containers for these wastes will be located around the site and will be emptied regularly so as to prevent wind-blown litter. This waste will also be removed by a contract hauler. All hazardous waste material such as oil filters, petroleum products, paint and equipment maintenance fluids will be stored in structurally sound and sealed shipping containers in the hazardous-materials storage area and segregated from other non-waste materials. Secondary containment will be provided for all materials in the hazardous materials storage area and will consist of commercially available spill pallets. Additionally, all hazardous materials will be disposed of in accordance with federal, state and municipal regulations. Two temporary sanitary facilities (portable toilets) will be provided at the site in the combined staging area. The toilets will be away from a concentrated flow path and traffic flow and will have collection pans underneath as secondary treatment. All sanitary waste will be collected from an approved party at a minimum of three times per week. 3.10.3 Building Material Staging Areas Construction equipment and maintenance materials will be stored at the combined staging area and materials storage areas. Silt fence will be installed around the perimeter to designate the staging and materials storage area. A watertight shipping container will be used to store hand tools, small parts and other construction materials. Non-hazardous building materials such as packaging material (wood, plastic and glass) and construction scrap material (brick, wood, steel, metal scraps, and pine cuttings) will be stored in a separate covered storage facility adjacent to other stored materials. All hazardous-waste materials such as oil filters, petroleum products, paint and equipment maintenance fluids will be stored in structurally sound and sealed containers under cover within the hazardous materials storage area. Large items such as framing materials and stockpiled lumber will be stored in the open storage area. Such materials will be elevated on wood blocks to minimize contact with runoff. The combined storage areas are expected to remain clean, well-organized and equipped with ample cleaning supplies as appropriate for the materials being stored. Perimeter controls such as containment structures, covers and liners will be repaired or replaced as necessary to maintain proper function. Stormwater Report 811 Route 28 South Yarmouth, MA 3.10.4 Designated Washout Areas Designated temporary, below-ground concrete washout areas will be constructed, as required, to minimize the pollution potential associated with concrete, paint, stucco, mixers etc. Signs will, if required, be posted marking the location of the washout area to ensure that concrete equipment operators use the proper facility. Concrete pours will not be conducted during or before an anticipated precipitation event. All excess concrete and concrete washout slurries from the concrete mixer trucks and chutes will be discharged to the washout area or hauled off-site for disposal. 3.10.5 Equipment/Vehicle Maintenance and Fueling Areas Several types of vehicles and equipment will be used on-site throughout the project including graders, scrapers, excavators, loaders, paving equipment, rollers, trucks and trailers, backhoes and forklifts. All major equipment/vehicle fueling and maintenance will be performed off-site. A small, 20-gallon pickup bed fuel tank will be kept on-site in the combined staging area. When vehicle fueling must occur on-site, the fueling activity will occur in the staging area. Only minor equipment maintenance will occur on-site. All equipment fluids generated from maintenance activities will be disposed of into designated drums stored on spill pallets. Absorbent, spill-cleanup materials and spill kits will be available at the combined staging and materials storage area. Drip pans will be placed under all equipment receiving maintenance and vehicles and equipment parked overnight. 3.10.6 Equipment/Vehicle Wash down Area All equipment and vehicle washing will be performed off-site. 3.10.7 Spill Prevention Plan A spill containment kit will be kept on-site in the Contractor’s trailer and/or the designated staging area throughout the duration of construction. Should there be an accidental release of petroleum product into a resource area, the appropriate agencies will be immediately notified. 3.10.8 Inspections Maintenance of existing and proposed BMP’s to address stormwater management facilities during construction is an on-going process. The purpose of the inspections is to observe all sources of stormwater or non-stormwater discharge as identified in the SWPPP as well as the status of the receiving waters and fulfill the requirements of the Order of Conditions. The following sections describe the appropriate inspection measures to adequately implement the project’s SWPPP. A blank inspection form is provided at the end of this section. Completed inspection forms are to be maintained on site. Inspection Personnel The owner’s appointed representative will be responsible for performing regular inspections of erosion controls and ordering repairs as necessary. Inspection Frequency Inspections will be performed by qualified personnel once every 7 days, in accordance with the CGP. The inspections must be documented on the inspection form provided at the end of this section, and completed forms will be provided to the on-site supervisor and maintained at the Owner’s office throughout the entire duration of construction. Inspection Reporting Each inspection report will summarize the scope of the inspection, name(s) and qualifications of personnel making the inspection, and major observations relating to the implementation of the SWPPP, including compliance and non-compliance items. Completed inspection reports will remain with the completed SWPPP on site. Stormwater Report 811 Route 28 South Yarmouth, MA 3.10.9 Amendment Requirements The final SWPPP is intended to be a working document that is utilized regularly on the construction site, and provides guidance to the Contractor. It must reflect changes made to the originally proposed plan and will be updated to include project specific activities and ensure that they are in compliance with the NPDES General Permit and state and local laws and regulations. It should be amended whenever there is a change in design, construction, operation or maintenance that affects discharge of pollutants. The following items should be addressed should an amendment to the SWPPP occur: Dates of certain construction activities such as major grading activities, clearing and initiation of and completion of stabilization measures should be recorded. Future amendments to the SWPPP will be recorded as required. As this SWPPP is amended, all amendments will be kept on site and made part of the SWPPP. Upon completion of site stabilization (completed as designed and/or 70% background vegetative cover), it can be documented and marked on the plans. Inspections are no longer required at this time. Inspections often identify areas not included in the original SWPPP, which will require the SWPPP to be amended. These updates should be made within seven days of being recognized by the inspector. 3.11 SWPPP Inspection and Maintenance Report The following form is an example to be used for SWPPP Inspection Reporting. Stormwater Report 811 Route 28 South Yarmouth, MA Stormwater Construction Site Inspection and Maintenance Report TO BE COMPLETED AT LEAST EVERY 7 DAYS. AFTER SITE STABILIZATION, TO BE COMPLETED AT LEAST ONCE PER MONTH FOR THREE YEARS OR UNTIL A NOTICE OF TERMINATION IS FILED (IF APPLICABLE). General Information Project Name 811 Route 28 Multi-Family Residential NPDES Tracking No. if applicable) Location 811 Route 28 South Yarmouth, MA Date of Inspection Start/End Time Inspector’s Name(s) Inspector’s Title(s) Inspector’s Contact Information Inspector’s Qualifications Describe present phase of construction Type of Inspection: Regular Pre-storm event During storm event Post-storm event Weather Information Has there been a storm event since the last inspection? Yes No If yes, provide: Storm Start Date & Time: Storm Duration (hrs): Approximate Amount of Precipitation (in): Weather at time of this inspection? Clear Cloudy Rain Sleet Fog Snowing High Winds Other: Temperature: Have any discharges occurred since the last inspection? Yes No If yes, describe: Are there any discharges at the time of inspection? Yes No If yes, describe: Site-specific BMPs Number the structural and non-structural BMPs identified in your SWPPP on your site map and list them below (add as many BMPs as necessary). Carry a copy of the numbered site map with you during your inspections. This list will ensure that you are inspecting all required BMPs at your site. Describe corrective actions initiated, date completed, and note the person that completed the work in the Corrective Action Log. BMP BMP Installed? BMP Maintenance Required? Corrective Action Needed and Notes Action required by whom and when 1 Catch Basin Protection Yes No Yes No 2 Haybale & Silt Fencing Yes No Yes No Stormwater Report 811 Route 28 South Yarmouth, MA BMP BMP Installed? BMP Maintenance Required? Corrective Action Needed and Notes Action required by whom and when 3 Straw Wattles Yes No Yes No 4 Construction Entrance Yes No Yes No 5 Sediment Basins Yes No Yes No 6 Dewatering Pit Yes No Yes No 7 Yes No Yes No Overall Site Issues Below are some general site issues that should be assessed during inspections. Customize this list as needed for conditions at your site. BMP/activity Implemented? Maintenance Required? Corrective Action Needed and Notes Action required by whom and when 1 Are all slopes and disturbed areas not actively being worked properly stabilized? Yes No Yes No 2 Are natural resource areas (e.g., streams, wetlands, mature trees, etc.) protected with barriers or similar BMPs? Yes No Yes No 3 Are perimeter controls and sediment barriers adequately installed keyed into substrate) and maintained? Yes No Yes No Stormwater Report 811 Route 28 South Yarmouth, MA BMP/activity Implemented? Maintenance Required? Corrective Action Needed and Notes Action required by whom and when 4 Are discharge points and receiving waters free of any sediment deposits? Yes No Yes No 5 Are storm drain inlets properly protected? Yes No Yes No 6 Is the construction exit preventing sediment from being tracked into the street? Yes No Yes No 7 Is trash/litter from work areas collected and placed in covered dumpsters? Yes No Yes No 8 Are washout facilities e.g., paint, stucco, concrete) available, clearly marked, and maintained? Yes No Yes No 9 Are vehicle and equipment fueling, cleaning, and maintenance areas free of spills, leaks, or any other deleterious material? Yes No Yes No Vehicle Maintenance not allowed on site 10 Are materials that are potential stormwater contaminants stored inside or under cover? Yes No Yes No 11 Are non-stormwater discharges (e.g., wash water, dewatering) properly controlled? Yes No Yes No 12 (Other) Yes No Yes No Non-Compliance Describe any incidents of non-compliance not described above: Stormwater Report 811 Route 28 South Yarmouth, MA CERTIFICATION STATEMENT 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.” Print name and title: . Qualified Person Performing the Inspection) Signature:_____________________________________________________ Date: . Print name and title: __________________________________________________________________________ Contractor/Operator) Signature:______________________________________________________ Date: Stormwater Report 811 Route 28 South Yarmouth, MA SECTION 4.0 LONG-TERM POLLUTION PREVENTION & OPERATION AND MAINTENANCE PLAN Stormwater Report 811 Route 28 South Yarmouth, MA 4.0 LONG-TERM POLLUTION PREVENTION & OPERATION AND MAINTENANCE PLAN As required by Standard #4 of the Stormwater Management Policy, this Long-Term Pollution Prevention Plan has been developed for source control and pollution prevention at the site after construction. MAINTENANCE RESPONSIBILITY Ensuring that the provisions of the Long-Term Pollution Prevention Plan are followed will be the responsibility of The Applicant, Christina Meggison. GOOD HOUSEKEEPING PRACTICES The site to be kept clean of trash and debris at all times. Trash, junk, etc. is not to be left outside. VEHICLE WASHING CONTROLS The following BMP’s, or equivalent measures, methods or practices are required if you are engaged in vehicle washing and/or steam cleaning: It is allowable to rinse down the body or a vehicle, including the bed of a truck, with just water without doing any wash water control BMP’s. If you wash (with mild detergents) on an area that infiltrates water, such as gravel, grass, or loose soil, it is acceptable to let the wash water infiltrate as long as you only wash the body of vehicles. However, if you wash on a paved area and use detergents or other cleansers, or if you wash/rinse the engine compartment or the underside of vehicles, you must take the vehicles to a commercial vehicle wash. REQUIREMENTS FOR ROUTINE INSPECTIONS AND MAINTENANCE OF STORMWATER BMPS All stormwater BMPs are to be inspected and maintain as follows; Haybales, Silt Fence, and other temporary measures The temporary erosion control measures will be installed up gradient of any wetland resource area where any disturbance or alteration might otherwise allow for erosion or sedimentation. They will be regularly inspected to ensure that they are functioning adequately. Additional supplies of these temporary measures will be stockpiled on site for any immediate needs or routine replacement. Deep Sump Hooded Catch Basins Regular maintenance is essential. Catch basins remain effective at removing pollutants only if they are cleaned out frequently. Inspect or clean basins at least four times per year and at the end of the foliage and snow removal seasons. Sediments must also be removed four times per year or whenever the depth of the deposits in the catch basin sump is greater than or equal to one half the depth from the bottom of the invert of the lowest pipe in the basin. Underground Infiltration System Maintenance is required for the proper operation of the underground infiltration system. Infiltration systems are prone to failure due to clogging if the upstream water quality units are not maintained. The use of pretreatment BMPs will minimize failure and maintenance requirements. After construction, the infiltration system shall be inspected after every major storm for the first few months to ensure proper stabilization and function. Water levels in the access ports shall be recorded over several days to check the drainage of the systems. It is recommended that a log book be maintained showing the depth of water in the detention/infiltration systems at each observation in order to determine the rate at which the system dewaters after runoff producing storm events. Once the performance characteristics of the detention/infiltration have been verified, the monitoring schedule can be reduced to an annual basis, unless the performance data suggests that a more frequent schedule is required. Stormwater Report 811 Route 28 South Yarmouth, MA Preventive maintenance on the infiltration system shall be performed at least twice a year, and sediment shall be removed from any and all pretreatment and collection structures. Sediment shall be removed when deposits approach within six inches of the invert heights of connecting pipes between unit rows, or in sumped inlet structures. Ponded water inside the systems (as visible from the access ports) that remains after several days most likely indicates that the bottom of the system is clogged and will require cleaning or replacement. The system is designed with a defined top portal area at the “down-flow” end of the chamber that can be cut out to accept up to a 10-inch diameter riser pipe. The 10-inch riser can be used as an observation well and as access for a vacuum truck tube for use in removing sediment. The “down flow” ends of the units have end walls that are closed on the bottom. The closed bottom functions like a coffer dam, with most of the sediment depositing prior to flowing into the next chamber, facilitating its removal through the riser pipe, which is positioned directly above this area. Bioretention Area Bioretention areas require routine maintenance to ensure that the system functions well as a stormwater Best Management Practice (BMP) and maintain an aesthetic element. A landscaping contractor working elsewhere on the site can complete maintenance tasks in many cases. Systems require careful attention while plants are being established and seasonal landscaping thereafter. Proper selection of plant species and support during establishment of vegetation should minimize-if not eliminate-the need for fertilizers and pesticides. Bioretention areas should be inspected on a semi-annual basis and after major storm events. The system should be inspected monthly for erosion. Eroded areas shall be repaired by reseeding or mulching as necessary. Vegetated areas should be properly maintained and mowed to a height of 2-inches. Accumulated litter and debris should be periodically removed to assure that the storage areas will function properly. Inlet and outlet structures should be inspected periodically and after every storm to assure that they are functioning properly. Vegetation will be inspected twice per year, at the beginning and end of the growing season. Dead and diseased vegetation should be removed and replaced. Weeds and invasive species shall be removed, and woody vegetation shall be pruned as necessary. PROVISIONS FOR MAINTENANCE OF LAWNS, GARDENS AND OTHER LANDSCAPE AREAS Suggested Maintenance Operations A. Trees and Shrubs Disease and Pest Management - Prevention of disease or infestation is the first step of Pest Management. A plant that is in overall good health is far less susceptible to disease. Good general landscape maintenance can reduce problems from disease. Inspections of plant materials for signs of disease or infestation are to be performed monthly by the Landscape Maintenance Contractor’s Certified Arborist. This is a critical step for early diagnosis. Trees and Shrubs that have been diagnosed to have a plant disease or an infestation of insect pests are to be treated promptly with an appropriate material by a licensed applicator. Fertilization - Trees and shrubs live outside their natural environment and should be given proper care to maintain health and vigor. Fertilizing trees and shrubs provides the plants with nutrients needed to resist insect attack, to resist drought and to grow thicker foliage. Fertilizing of new and old trees may be done in one of three ways, in either the early spring or the late fall. Systemic Injection of new and existing trees on trees 2 inches or greater in diameter. You must be licensed to apply this method. Soil Injection – a liquid fertilizer with a product such as Arbor Green or Rapid Grow injected into the soil under the drip zone of a tree or shrub. Material must be used according to manufacturers’ specifications to be effective. Outside contracting is recommended. Stormwater Report 811 Route 28 South Yarmouth, MA Punch Bar Method – a dry fertilizer such as 10-10-10, may be used by punched holes in the drip zone of the tree 12-18” deep, two feet apart around the circumference, to the edge of the drip line. Three pounds of fertilizer should be used per diameter inch for trees with trunks six inches or more in diameter. Fertilizer of shrubs – use a fertilizer such as 10-10-10, broadcast over the planting area according to the manufacturers’ rate and water in. All fertilization must be noted on daily maintenance log. Watering - Trees and Shrubs will need supplemental watering to remain in vigorous health. All new plants need to be watered once a week in cool weather, twice a week during warm weather, and up to three times in a week during periods of extreme heat and drought. Trees and shrubs should be watered in such a manner as to totally saturate the soil in the root zone area. Over-watering or constant saturation of the soil must be avoided as this could lead to root rot and other disease problems. The use of a soil moisture meter can help you monitor the soil’s water intake. Plant Replacement - Unhealthy plants that may cause widespread infestation of other nearby plants shall be immediately removed from the site. Any vegetation removed from the site must be recorded and submitted with the daily maintenance log. The area shall be treated to prevent further infestation. The plant shall then be replaced with a healthy specimen of the same species and size. This work shall have a pre-established budget allowance for the year. A spring inspection of all plant materials shall be performed to identify those plant materials that are not in vigorously healthy condition. Unhealthy plant materials shall be evaluated. If the problem is determined to be minor the plant material shall be given appropriate restorative care in accordance with this maintenance guideline until it is restored to a vigorously healthy condition. Unhealthy plant materials that do not respond to restorative care or are determined to be beyond saving shall be replaced with a healthy specimen of the same species and size. In the case of the necessity of replacing extremely large plant materials the Landscape Architect shall determine the size of the replacement plant. Pruning - Proper pruning is the selective removal of branches without changing the plant’s natural appearance, or habit of growth. All tree pruning is to be performed by a licensed Arborist. All branches that are dead, broken, scared or crossing should be removed. All cuts should be made at the collar and not cut flush with the base. Pruning on the site shall be done for the following purposes; To maintain or reduce the size of a tree or shrub To remove dead, diseased or damaged branches To rejuvenate old shrubs and encourage new growth To stimulate future flower and fruit development To maximize the visibility of twig color To prevent damage and reduce hazards to people and properties All shrubs are recommended to be pruned on an annual basis to prevent the shrub from becoming overgrown and eliminate the need for drastic pruning. There are several types of pruning for deciduous shrubs. Hand snips should be used to maintain a more natural look or hand shears can be used for a more formal appearance. Winter Protection - All trees and shrubs are to be watered, fertilized, and mulched before the first frost. All stakes should be checked and ties adjusted. Damaged branches should be pruned. Broadleaf and Coniferous Evergreen plant materials are to be sprayed with an anti-desiccant product to prevent winter burn. The application shall be repeated during a suitable mid-winter thaw. Shrubs located in areas likely to be piled with snow during snow removal (but not designated as Snow Storage Areas) shall be marked by six-foot high poles with bright green banner flags. Stockpiles of snow are not to be located in these areas due to potential damage to the plant materials from both the weight of the snow and the snow melting chemicals. At the fall landscape maintenance conference parameters will be discussed between the Landscape Maintenance Contractor and the snow removal contractor to assure minimal damage and loss of landscape amenities during the winter season. Stormwater Report 811 Route 28 South Yarmouth, MA Seasonal Clean Up - A thorough spring cleanup is to be performed. This includes the removal and replacement of dead or unhealthy plant materials and the cleanup of plant debris and any general debris that has accumulated over the winter season. Mulch is to be lightly raked to clean debris from the surface without removing any mulch. Twigs and debris are to be removed from the planting beds throughout the growing season. Mulching - Planting beds shall be mulched with a treated shredded hardwood mulch free from dirt, debris, and insects. A sample of this mulch shall be given to the Owner for approval prior to installation. Maintain a 2-3” maximum depth and keep free of weeds either by hand weeding or by the use of a pre-emergent weed control such as Treflan or Serfian. Seasonal re-mulching shall occur as necessary in the spring and the fall to maintain this minimum depth. When new mulch is added to the planting bed it shall be spread to create a total depth of no more than three inches. Edges should be maintained in a cleanly edged fashion. Mulch shall not be placed directly against the trunk of any tree or shrub. B. Groundcover and Perennials Disease and Pest Management – Pesticides and herbicides should be applied only as problems occur, with the proper chemical applied only by a trained professional or in the case of pesticide, a Certified Pesticide Applicator. Plants should be monitored weekly and treated accordingly. Fertilizer – The health of the plants can be maintained or improved, and their growth encouraged by an application of complete fertilizer. Apply a fertilizer such as 4-12-4 as growth becomes apparent and before mulching. Apply to all groundcover and perennial planting areas by hand and avoid letting the fertilizer come in contact with the foliage, or use a liquid fertilizer and apply by soaking the soil. Apply according to the manufacturers’ specifications. Fertilization shall stop at the end of July. Water – Groundcovers and Perennials will need supplemental watering in order to become established, healthy plants. All new plants need to be watered once a week in cool weather, twice a week during warm weather, and up to three times in a week during periods of extreme heat and drought. Until established, groundcovers and perennials should be watered in such a manner as to totally saturate the soil in the root zone area, to a depth of 6 inches. Once established, perennials shall continue to be watered as necessary to maintain them in a vigorous healthy condition. Over-watering or constant saturation of the soil must be avoided as this could lead to root rot and other disease problems. The use of a soil moisture meter can help you monitor the soil’s water intake. On-site water shall be furnished by the Owner. Hose and other watering equipment shall be furnished by the Landscape Maintenance Contractor. Replacement – Any unhealthy plant/s that may cause widespread infestation of other nearby plants shall be immediately removed from the site. Any vegetation removed from the site must be recorded and submitted with the landscape maintenance log. The area shall be treated to prevent further infestation. The plant/s shall then be replaced with healthy specimen/s of the same species and size. Old Forge shall have a pre-established budget allowance for this type of replacement, each year. Plant material that is damaged as a result of other landscape maintenance activities, such as mowing, shall be replaced with healthy specimens of the same species and size, at no additional cost to the owner. Deadheading – Perennials shall be checked on a weekly basis and dead-headed once flowers have faded or as necessary based on plant type and duration of flower. Spent flowers can be pinched off with the thumb and forefinger. Continue to remove all faded flowers until Fall. All associated debris shall be removed from site daily. Staking – Upright-growing perennials need support especially when in flower. Use of bamboo stakes, galvanized wire hoops or mesh may be necessary for their support. Supports should be put in place before they have become too difficult to handle. The supports should not be taller than the mature height of the perennial plant. Stormwater Report 811 Route 28 South Yarmouth, MA Division of Perennials – Two or three-year-old perennials are easily divided in the spring if more plants are needed. To divide, cut out the entire section of plant to be divided, including roots. The larger divisions (those with three or more shoots), can be set out immediately in their permanent location, where they can be expected to bloom the same season. Smaller divisions are best planted in an out-of-the-way planting bed until the following autumn or spring, when they can be moved to their permanent location. Weeding – All planting beds should be kept weed-free. Weed either by hand or with a pre-emergent herbicide such as Treflen used according to manufacturers’ specifications. Manual weeding is to be used in combination with the use of spot applications of herbicides. Both live and dead weeds are to be pulled and removed from the site. All herbicide applications shall be documented in the Landscape Maintenance Log. The actual product label or the manufacturer’s product specification sheet for the specific product shall also be included in the Log. Only personnel with appropriate applicator licenses shall supervise and/or perform the application of pesticide products requiring a license. Winterizing – Perennial gardens should be cleaned-up when growth ceases in the fall. Remove foliage of plants that normally die down to the ground. Divide and replant over-grown clumps. C. Lawn Areas - Turf Systems Mowing – Proper mowing is an integral part of any good turf maintenance program. Without it, the finest in fertilization, watering and other vital maintenance practices would be completely ineffective. Proper mowing will help control dicot weeds; help the turf survive during periods of extreme heat, and gain strength and vigor to resist disease and other infestations. Mowing height – The proper mowing height will vary somewhat according to the type of grass. The most common type of seed & sod lawns contain a mixture of bluegrass, fine fescue and perennial rye, which should be mowed at 2-3 inches. Mowing frequency – The basic rule of thumb for mowing frequency is to never remove more than 1/3 of the grass blade in one mowing. Example: if you want to mow your turf at 2 inches, you should cut it when it reaches 3 inches. Removing more than ½ of the grass plant at a time can put the plant into shock, thus making it more susceptible to stress disease and weed infestation. Mowing frequency will vary with the growing season and should be set by the plant height and not a set date. It will often be necessary to mow twice a week during periods of surge growth to help maintain plant health and color. Mowing should be cut back during periods of stress. Grass clippings should be removed whenever they are thick enough to layer the turf. The return of clippings to the soil actually adds nutrients and helps retain moisture. Heavily clumped grass clippings are a sign of infrequent mowing, calling for an adjustment in the mowing schedule. When mowing any area, try to alternate mowing patterns. This tends to keep grass blades more erect and assures an even cut. A dull mower will cause color loss due to tearing of the turf plant, and since mowing will ultimately determine the appearance of any turf area there is an absolute necessity for a clean sharp cut. Weed & Pest Control and Fertilizing- In order to maintain turf grass health, vigor color, and nutrients, fertilizer must be added to the soil. Recommendations for fertilization of lawn areas are as follows; fertilize at the rate of one (1) pound of nitrogen per thousand square feet, per year is optimum. Fertilizer should be a balanced slow release, sulfur coated type fertilizer. Weed Control - All turf areas will require some weed control, for both weed grasses and dicot weeds. Weeds should be treated at the appropriate time and with a material labeled for the target weed. Please refer to the fertilizer weed and pest schedule for timing. Stormwater Report 811 Route 28 South Yarmouth, MA Pest Control - All turf areas will require some pest control. Pests should be treated at the appropriate time with a material labeled for the target pest. Please refer to the fertilizer, weed and pest schedule for timing. Lime - A common cause for an unhealthy lawn is acidic soil. When the pH is below the neutral range (between 6-7) vital plant nutrients become fixed in the soil and cannot be absorbed by the grass plant. Lime corrects an acid soil condition, supplies calcium for plant growth and improves air and water circulation. Limestone applied at the rate of 50 lbs. per thousand square feet will adjust the soil pH one point over a period of 6-9 months. D. Fertilizer, Weed & Pest Control Schedule – Turf Systems Spring - Fertilize one (1) pound of nitrogen per 1,000 square feet April) Pre-emergent weed grass control Broadleaf weed control Late Spring - Fertilize one (1) pound of nitrogen per 1,000 square feet June) Pre-emergent weed grass control Broadleaf weed control Insect Control (if needed) Summer - Fertilize one (1) pound of nitrogen per 1,000 square feet August) Broadleaf weed control (if needed) Insect Control (if needed) Fall - Fertilize one (1) pound of nitrogen per 1,000 square feet September) Omit if area is not to be irrigated Lawn Maintenance Task Schedule MARCH (Weather permitting) Clean up winter debris, sand, leaves, trash etc. Re-edge mulch beds, maintain at 2-3” maximum. Fertilize plants Aerate and thatch turf (conditions permitting) APRIL Reseed or sod all areas needing attention. Fertilize and weed control Lime Start mowing when grass reaches 2-1/2”, mow to 2” MAY Mow turf to 2-2-1/2” Weed as necessary. Check for disease and pest problems in both turf and plants. JUNE Mow turf to 2-1/2” – 3” Fertilize and weed control. Weed Stormwater Report 811 Route 28 South Yarmouth, MA Check for disease and pest problems in both turf and plants, treat as necessary. PROVISIONS FOR SOLID WASTE MANAGEMENT (SITE TRASH) Trash will be placed in on-site dumpsters and the Owner will make provisions for its regular and timely removal. SNOW DISPOSAL AND PLOWING PLANS The purpose of the snow and snowmelt management plan is to provide guidelines regarding snow disposal site selection, site preparation and maintenance that are acceptable to the Department of Environmental Protection. For the areas that require snow removal, snow storage onsite will largely be accomplished by using pervious areas along the shoulder of the roadway and development as windrowed by plows. Avoid dumping of snow into any water body, including rivers, ponds, or wetlands. In addition to water quality impacts and flooding, snow disposed of in open water can cause navigational hazards when it freezes into ice blocks. Avoid disposing of snow on top of storm drain catch basins or in stormwater basins. Snow combined with sand and debris may block a storm drainage system, causing localized flooding. A high volume of sand, sediment, and litter released from melting snow also may be quickly transported through the system into surface water. In significant storm events, the melting or off-site trucking of snow may be implemented. These activities shall be conducted in accordance with all local, state and federal regulations. Snow shall be removed from the areas around on-site fire-hydrants to maintain emergency access to hydrants at all times. Removable flags or markers should be placed on hydrants to allow snow removal crews to more easily locate hydrants and not damage them with plows or other snow removal equipment. WINTER ROAD SALT AND/OR SAND USE AND STORAGE RESTRICTIONS The applicant will be responsible for sanding and salting the site. No storage on site. STREET SWEEPING SCHEDULES There are three types of sweepers: Mechanical, Regenerative Air, and Vacuum Filter. 1) Mechanical: Mechanical sweepers use brooms or rotary brushes to scour the pavement. 2) Regenerative Air: These sweepers blow air onto the road or parking lot surface, causing fines to rise where they are vacuumed. 3) Vacuum filter: These sweepers remove fines along roads. Two general types of vacuum filter sweepers are available - wet and dry. The dry type uses a broom in combination with the vacuum. The wet type uses water for dust suppression Regardless of the type chosen, the efficiency of street sweeping is increased when sweepers are operated in tandem. This project has not included street sweeping as part of the TSS removal calculations. However, it is recommended that street sweeping of the parking areas occur four times a year, including once after the spring snow melt. Reuse and Disposal of Street Sweepings Once removed from paved surfaces, the sweepings must be handled and disposed of properly. Mass DEP’s Bureau of Waste Prevention has issued a written policy regarding the reuse and disposal of street sweepings. These sweepings are regulated as a solid waste, and can be used in three ways: In one of the ways already approved by Mass DEP (e.g., daily cover in a landfill, additive to compost, fill in a public way) If approved under a Beneficial Use Determination Disposed in a landfill Stormwater Report 811 Route 28 South Yarmouth, MA TRAINING OF STAFF OR PERSONNEL INVOLVED WITH IMPLEMENTING LONG-TERM POLLUTION PREVENTION PLAN The Long-Term Pollution Prevention Plan is to be implemented by property owner of the site. Trained and, if required, licensed Professionals are to be hired by the owner as applicable to implement the Long-Term Pollution Prevention Plan. LIST OF EMERGENCY CONTACTS FOR IMPLEMENTING LONG-TERM POLLUTION PREVENTION PLAN The applicant will be required to implement the Long-Term Pollution Prevention Plan and will create and maintain a list of emergency contacts. Stormwater Report 811 Route 28 South Yarmouth, MA POST CONSTRUCTION PHASE INSPECTION SCHEDULE AND EVALUATION CHECKLIST Inspection Date Inspector BMP Inspected Inspection Frequency Requirement s Comments Recommendation Follow-up Inspection Required yes/no) Catch Basin Four times a year Infiltration System Twice a year Bioretention Area Twice a year 1. Refer to the Massachusetts Stormwater Handbook Volume Two: Stormwater Technical Handbook (February 2008) for recommendations regarding frequency for inspections and maintenance of specific BMP’s 2. Inspections to be conducted by a qualified professional such as an environmental scientist or civil engineer. 3. Limited or no use of sodium chloride salts, fertilizers or pesticides recommended. 4. Other Notes: (Include deviations from Conservation Commission Approvals, Planning Board Approvals and Approved Plans) Stormwater Report 811 Route 28 South Yarmouth, MA SECTION 5.0 HYDROLOGY CALCULATIONS Stormwater Report 811 Route 28 South Yarmouth, MA 5.01 EXISTING WATERSHED PLAN Stormwater Report 811 Route 28 South Yarmouth, MA 5.02 EXISTING HYDROLOGY CALCULATIONS HYDROCAD™ PRINTOUTS) 1S On-Site Flow 2S Off-Site (North) 3S Off Site (South) 1R On-Site 2R Route 28 3R Off-Site (South) Routing Diagram for 5064600-PRE Prepared by BSC Group, Printed 3/20/2024 HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcat Reach Pond Link EWAM 5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page2HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Rainfall Events Listing Event# Event Name Storm Type Curve Mode Duration hours) B/B Depth inches) AMC 1 2-year Type III 24-hr Default 24.00 1 3.36 2 2 10-year Type III 24-hr Default 24.00 1 4.89 2 3 25-year Type III 24-hr Default 24.00 1 5.85 2 4 50-year Type III 24-hr Default 24.00 1 6.57 2 5 100-year Type III 24-hr Default 24.00 1 7.32 2 EWAM 5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page3HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Area Listing (all nodes) Area acres) CN Description subcatchment-numbers) 0.201 39 >75% Grass cover, Good, HSG A (1S, 2S, 3S) 0.022 72 Dirt roads, HSG A (1S) 0.142 96 Gravel surface, HSG A (1S, 2S) 0.131 98 Paved parking, HSG A (1S, 2S) 0.024 98 Roofs, HSG A (1S, 3S) 0.003 98 Unconnected pavement, HSG A (1S) 0.054 30 Woods, Good, HSG A (1S) 0.088 32 Woods/grass comb., Good, HSG A (1S, 2S) 0.666 65 TOTAL AREA EWAM 5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page4HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area acres) Soil Group Subcatchment Numbers 0.666 HSG A 1S, 2S, 3S 0.000 HSG B 0.000 HSG C 0.000 HSG D 0.000 Other 0.666 TOTAL AREA EWAM 5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page5HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A acres) HSG-B acres) HSG-C acres) HSG-D acres) Other acres) Total acres) Ground Cover Subcatchment Numbers 0.201 0.000 0.000 0.000 0.000 0.201 >75% Grass cover, Good 1S, 2S, 3S 0.022 0.000 0.000 0.000 0.000 0.022 Dirt roads 1S 0.142 0.000 0.000 0.000 0.000 0.142 Gravel surface 1S, 2S 0.131 0.000 0.000 0.000 0.000 0.131 Paved parking 1S, 2S 0.024 0.000 0.000 0.000 0.000 0.024 Roofs 1S, 3S 0.003 0.000 0.000 0.000 0.000 0.003 Unconnected pavement 1S 0.054 0.000 0.000 0.000 0.000 0.054 Woods, Good 1S 0.088 0.000 0.000 0.000 0.000 0.088 Woods/grass comb., Good 1S, 2S 0.666 0.000 0.000 0.000 0.000 0.666 TOTAL AREA EWAM Type III 24-hr 2-year Rainfall=3.36"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page6HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=26,357 sf 21.54% Impervious Runoff Depth=0.64"Subcatchment 1S: On-Site Flow Tc=6.0 min CN=64 Runoff=0.35 cfs 0.032 af Runoff Area=2,024 sf 56.08% Impervious Runoff Depth=1.46"Subcatchment 2S: Off-Site (North) Tc=6.0 min CN=79 Runoff=0.08 cfs 0.006 af Runoff Area=626 sf 14.38% Impervious Runoff Depth=0.10"Subcatchment 3S: Off Site (South) Tc=6.0 min CN=47 Runoff=0.00 cfs 0.000 af Inflow=0.35 cfs 0.032afReach1R: On-Site Outflow=0.35 cfs 0.032 af Inflow=0.08 cfs 0.006afReach2R: Route 28 Outflow=0.08 cfs 0.006 af Inflow=0.00 cfs 0.000afReach3R: Off-Site (South) Outflow=0.00 cfs 0.000 af Total Runoff Area = 0.666 ac Runoff Volume = 0.038 af Average Runoff Depth = 0.68" 76.20% Pervious = 0.507 ac 23.80% Impervious = 0.158 ac EWAM Type III 24-hr 2-year Rainfall=3.36"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page7HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 1S: On-Site Flow Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 38 0. 36 0. 34 0. 32 0. 3 0. 28 0. 26 0. 24 0. 22 0. 2 0. 18 0. 16 0. 14 0. 12 0. 1 0. 08 0. 06 0. 04 0. 02 0 Type III 24- hr 2-year Rainfall=3. 36"Runoff Area=26,357 sf Runoff Volume=0.032 af Runoff Depth=0. 64"Tc=6.0 min CN= 640.35 EWAM Type III 24-hr 2-year Rainfall=3.36"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page8HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 2S: Off-Site (North) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 085 0. 08 0. 075 0. 07 0. 065 0. 06 0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Type III 24- hr 2-year Rainfall=3. 36"Runoff Area=2,024 sf Runoff Volume=0.006 af Runoff Depth=1. 46"Tc=6.0 min CN= 79 0.08 EWAM Type III 24-hr 2-year Rainfall=3.36"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page9HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 3S: Off Site (South) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0 0 0 0 0 0 0 0 0 0 Type III 24- hr 2-year Rainfall=3. 36"Runoff Area=626 sf Runoff Volume=0.000 af Runoff Depth=0. 10"Tc=6.0 min CN= 47 0.00 EWAM Type III 24-hr 2-year Rainfall=3.36"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page10HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 1R: On-Site Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 38 0. 36 0. 34 0. 32 0. 3 0. 28 0. 26 0. 24 0. 22 0. 2 0. 18 0. 16 0. 14 0. 12 0. 1 0. 08 0. 06 0. 04 0. 02 0 Inflow Area=0.605 ac0.35 cfs0.35 EWAM Type III 24-hr 2-year Rainfall=3.36"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page11HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 2R: Route 28 Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 085 0. 08 0. 075 0. 07 0. 065 0. 06 0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Inflow Area=0.046 ac 0.08 cfs0.08 EWAM Type III 24-hr 2-year Rainfall=3.36"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page12HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 3R: Off-Site (South) Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0 0 0 0 0 0 0 0 0 0 Inflow Area=0.014 ac0.00 cfs0.00 EWAM Type III 24-hr 10-year Rainfall=4.89"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page13HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=26,357 sf 21.54% Impervious Runoff Depth=1.51"Subcatchment 1S: On-Site Flow Tc=6.0 min CN=64 Runoff=1.00 cfs 0.076 af Runoff Area=2,024 sf 56.08% Impervious Runoff Depth=2.71"Subcatchment 2S: Off-Site (North) Tc=6.0 min CN=79 Runoff=0.15 cfs 0.010 af Runoff Area=626 sf 14.38% Impervious Runoff Depth=0.50"Subcatchment 3S: Off Site (South) Tc=6.0 min CN=47 Runoff=0.00 cfs 0.001 af Inflow=1.00 cfs 0.076afReach1R: On-Site Outflow=1.00 cfs 0.076 af Inflow=0.15 cfs 0.010afReach2R: Route 28 Outflow=0.15 cfs 0.010 af Inflow=0.00 cfs 0.001afReach3R: Off-Site (South) Outflow=0.00 cfs 0.001 af Total Runoff Area = 0.666 ac Runoff Volume = 0.087 af Average Runoff Depth = 1.57" 76.20% Pervious = 0.507 ac 23.80% Impervious = 0.158 ac EWAM Type III 24-hr 10-year Rainfall=4.89"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page14HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 1S: On-Site Flow Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 1 0 Type III 24- hr 10-year Rainfall=4. 89"Runoff Area=26,357 sf Runoff Volume=0.076 af Runoff Depth=1. 51"Tc=6.0 min CN= 64 1.00 EWAM Type III 24-hr 10-year Rainfall=4.89"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page15HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 2S: Off-Site (North) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 16 0. 15 0. 14 0. 13 0. 12 0. 11 0. 1 0. 09 0. 08 0. 07 0. 06 0. 05 0. 04 0. 03 0. 02 0. 01 0 Type III 24- hr 10-year Rainfall=4. 89"Runoff Area=2,024 sf Runoff Volume=0.010 af Runoff Depth=2. 71"Tc=6.0 min CN= 790.15 EWAM Type III 24-hr 10-year Rainfall=4.89"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page16HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 3S: Off Site (South) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 004 0. 004 0. 004 0. 003 0. 003 0. 003 0. 003 0. 003 0. 002 0. 002 0. 002 0. 002 0. 002 0. 001 0. 001 0. 001 0. 001 0. 001 0. 000 0. 000 0 Type III 24- hr 10-year Rainfall=4. 89"Runoff Area=626 sf Runoff Volume=0.001 af Runoff Depth=0. 50"Tc=6.0 min CN= 470.00 EWAM Type III 24-hr 10-year Rainfall=4.89"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page17HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 1R: On-Site Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 1 0 Inflow Area=0.605 ac 1.00 cfs1.00 EWAM Type III 24-hr 10-year Rainfall=4.89"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page18HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 2R: Route 28 Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 16 0. 15 0. 14 0. 13 0. 12 0. 11 0. 1 0. 09 0. 08 0. 07 0. 06 0. 05 0. 04 0. 03 0. 02 0. 01 0 Inflow Area=0.046 ac0.15 cfs0.15 EWAM Type III 24-hr 10-year Rainfall=4.89"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page19HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 3R: Off-Site (South) Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 004 0. 004 0. 004 0. 003 0. 003 0. 003 0. 003 0. 003 0. 002 0. 002 0. 002 0. 002 0. 002 0. 001 0. 001 0. 001 0. 001 0. 001 0. 000 0. 000 0 Inflow Area=0.014 ac 0.00 cfs0.00 EWAM Type III 24-hr 25-year Rainfall=5.85"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page20HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=26,357 sf 21.54% Impervious Runoff Depth=2.16"Subcatchment 1S: On-Site Flow Tc=6.0 min CN=64 Runoff=1.48 cfs 0.109 af Runoff Area=2,024 sf 56.08% Impervious Runoff Depth=3.55"Subcatchment 2S: Off-Site (North) Tc=6.0 min CN=79 Runoff=0.19 cfs 0.014 af Runoff Area=626 sf 14.38% Impervious Runoff Depth=0.87"Subcatchment 3S: Off Site (South) Tc=6.0 min CN=47 Runoff=0.01 cfs 0.001 af Inflow=1.48 cfs 0.109afReach1R: On-Site Outflow=1.48 cfs 0.109 af Inflow=0.19 cfs 0.014afReach2R: Route 28 Outflow=0.19 cfs 0.014 af Inflow=0.01 cfs 0.001afReach3R: Off-Site (South) Outflow=0.01 cfs 0.001 af Total Runoff Area = 0.666 ac Runoff Volume = 0.124 af Average Runoff Depth = 2.23" 76.20% Pervious = 0.507 ac 23.80% Impervious = 0.158 ac EWAM Type III 24-hr 25-year Rainfall=5.85"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page21HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 1S: On-Site Flow Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 1 0 Type III 24- hr 25-year Rainfall=5. 85"Runoff Area=26,357 sf Runoff Volume=0.109 af Runoff Depth=2. 16"Tc=6.0 min CN= 64 1.48 EWAM Type III 24-hr 25-year Rainfall=5.85"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page22HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 2S: Off-Site (North) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 21 0. 2 0. 19 0. 18 0. 17 0. 16 0. 15 0. 14 0. 13 0. 12 0. 11 0. 1 0. 09 0. 08 0. 07 0. 06 0. 05 0. 04 0. 03 0. 02 0. 01 0 Type III 24- hr 25-year Rainfall=5. 85"Runoff Area=2,024 sf Runoff Volume=0.014 af Runoff Depth=3. 55"Tc=6.0 min CN= 790.19 EWAM Type III 24-hr 25-year Rainfall=5.85"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page23HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 3S: Off Site (South) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 011 0. 01 0. 009 0. 009 0. 008 0. 008 0. 007 0. 007 0. 006 0. 006 0. 005 0. 005 0. 004 0. 004 0. 003 0. 003 0. 002 0. 002 0. 001 0. 001 0. 000 0 Type III 24- hr 25-year Rainfall=5. 85"Runoff Area=626 sf Runoff Volume=0.001 af Runoff Depth=0. 87"Tc=6.0 min CN= 47 0.01 EWAM Type III 24-hr 25-year Rainfall=5.85"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page24HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 1R: On-Site Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 1 0 Inflow Area=0.605 ac 1.48 cfs1.48 EWAM Type III 24-hr 25-year Rainfall=5.85"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page25HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 2R: Route 28 Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 21 0. 2 0. 19 0. 18 0. 17 0. 16 0. 15 0. 14 0. 13 0. 12 0. 11 0. 1 0. 09 0. 08 0. 07 0. 06 0. 05 0. 04 0. 03 0. 02 0. 01 0 Inflow Area=0.046 ac0.19 cfs0.19 EWAM Type III 24-hr 25-year Rainfall=5.85"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page26HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 3R: Off-Site (South) Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 011 0. 01 0. 009 0. 009 0. 008 0. 008 0. 007 0. 007 0. 006 0. 006 0. 005 0. 005 0. 004 0. 004 0. 003 0. 003 0. 002 0. 002 0. 001 0. 001 0. 000 0 Inflow Area=0.014 ac 0.01 cfs0.01 EWAM Type III 24-hr 50-year Rainfall=6.57"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page27HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=26,357 sf 21.54% Impervious Runoff Depth=2.68"Subcatchment 1S: On-Site Flow Tc=6.0 min CN=64 Runoff=1.87 cfs 0.135 af Runoff Area=2,024 sf 56.08% Impervious Runoff Depth=4.19"Subcatchment 2S: Off-Site (North) Tc=6.0 min CN=79 Runoff=0.23 cfs 0.016 af Runoff Area=626 sf 14.38% Impervious Runoff Depth=1.19"Subcatchment 3S: Off Site (South) Tc=6.0 min CN=47 Runoff=0.02 cfs 0.001 af Inflow=1.87 cfs 0.135afReach1R: On-Site Outflow=1.87 cfs 0.135 af Inflow=0.23 cfs 0.016afReach2R: Route 28 Outflow=0.23 cfs 0.016 af Inflow=0.02 cfs 0.001afReach3R: Off-Site (South) Outflow=0.02 cfs 0.001 af Total Runoff Area = 0.666 ac Runoff Volume = 0.153 af Average Runoff Depth = 2.75" 76.20% Pervious = 0.507 ac 23.80% Impervious = 0.158 ac EWAM Type III 24-hr 50-year Rainfall=6.57"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page28HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 1S: On-Site Flow Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 2 1 0 Type III 24- hr 50-year Rainfall=6. 57"Runoff Area=26,357 sf Runoff Volume=0.135 af Runoff Depth=2. 68"Tc=6.0 min CN= 64 1.87 EWAM Type III 24-hr 50-year Rainfall=6.57"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page29HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 2S: Off-Site (North) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 25 0. 24 0. 23 0. 22 0. 21 0. 2 0. 19 0. 18 0. 17 0. 16 0. 15 0. 14 0. 13 0. 12 0. 11 0. 1 0. 09 0. 08 0. 07 0. 06 0. 05 0. 04 0. 03 0. 02 0. 01 0 Type III 24- hr 50-year Rainfall=6. 57"Runoff Area=2,024 sf Runoff Volume=0.016 af Runoff Depth=4. 19"Tc=6.0 min CN= 790.23 EWAM Type III 24-hr 50-year Rainfall=6.57"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page30HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 3S: Off Site (South) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 017 0. 016 0. 015 0. 014 0. 013 0. 012 0. 011 0. 01 0. 009 0. 008 0. 007 0. 006 0. 005 0. 004 0. 003 0. 002 0. 001 0 Type III 24- hr 50-year Rainfall=6. 57"Runoff Area=626 sf Runoff Volume=0.001 af Runoff Depth=1. 19"Tc=6.0 min CN= 47 0.02 EWAM Type III 24-hr 50-year Rainfall=6.57"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page31HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 1R: On-Site Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 2 1 0 Inflow Area=0.605 ac 1.87 cfs1.87 EWAM Type III 24-hr 50-year Rainfall=6.57"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page32HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 2R: Route 28 Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 25 0. 24 0. 23 0. 22 0. 21 0. 2 0. 19 0. 18 0. 17 0. 16 0. 15 0. 14 0. 13 0. 12 0. 11 0. 1 0. 09 0. 08 0. 07 0. 06 0. 05 0. 04 0. 03 0. 02 0. 01 0 Inflow Area=0.046 ac0.23 cfs0.23 EWAM Type III 24-hr 50-year Rainfall=6.57"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page33HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 3R: Off-Site (South) Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 017 0. 016 0. 015 0. 014 0. 013 0. 012 0. 011 0. 01 0. 009 0. 008 0. 007 0. 006 0. 005 0. 004 0. 003 0. 002 0. 001 0 Inflow Area=0.014 ac 0.02 cfs0.02 EWAM Type III 24-hr 100-year Rainfall=7.32"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page34HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=26,357 sf 21.54% Impervious Runoff Depth=3.25"Subcatchment 1S: On-Site Flow Tc=6.0 min CN=64 Runoff=2.28 cfs 0.164 af Runoff Area=2,024 sf 56.08% Impervious Runoff Depth=4.88"Subcatchment 2S: Off-Site (North) Tc=6.0 min CN=79 Runoff=0.26 cfs 0.019 af Runoff Area=626 sf 14.38% Impervious Runoff Depth=1.57"Subcatchment 3S: Off Site (South) Tc=6.0 min CN=47 Runoff=0.02 cfs 0.002 af Inflow=2.28 cfs 0.164afReach1R: On-Site Outflow=2.28 cfs 0.164 af Inflow=0.26 cfs 0.019afReach2R: Route 28 Outflow=0.26 cfs 0.019 af Inflow=0.02 cfs 0.002afReach3R: Off-Site (South) Outflow=0.02 cfs 0.002 af Total Runoff Area = 0.666 ac Runoff Volume = 0.184 af Average Runoff Depth = 3.32" 76.20% Pervious = 0.507 ac 23.80% Impervious = 0.158 ac EWAM Type III 24-hr 100-year Rainfall=7.32"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page35HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 1S: On-Site Flow Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 2 1 0 Type III 24- hr 100-year Rainfall=7. 32"Runoff Area=26,357 sf Runoff Volume=0.164 af Runoff Depth=3. 25"Tc=6.0 min CN= 64 2.28 EWAM Type III 24-hr 100-year Rainfall=7.32"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page36HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 2S: Off-Site (North) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 28 0. 26 0. 24 0. 22 0. 2 0. 18 0. 16 0. 14 0. 12 0. 1 0. 08 0. 06 0. 04 0. 02 0 Type III 24- hr 100-year Rainfall=7. 32"Runoff Area=2,024 sf Runoff Volume=0.019 af Runoff Depth=4. 88"Tc=6.0 min CN= 790.26 EWAM Type III 24-hr 100-year Rainfall=7.32"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page37HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 3S: Off Site (South) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 024 0. 023 0. 022 0. 021 0. 02 0. 019 0. 018 0. 017 0. 016 0. 015 0. 014 0. 013 0. 012 0. 011 0. 01 0. 009 0. 008 0. 007 0. 006 0. 005 0. 004 0. 003 0. 002 0. 001 0 Type III 24- hr 100-year Rainfall=7. 32"Runoff Area=626 sf Runoff Volume=0.002 af Runoff Depth=1. 57"Tc=6.0 min CN= 47 0.02 EWAM Type III 24-hr 100-year Rainfall=7.32"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page38HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 1R: On-Site Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 2 1 0 Inflow Area=0.605 ac 2.28 cfs2.28 EWAM Type III 24-hr 100-year Rainfall=7.32"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page39HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 2R: Route 28 Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 28 0. 26 0. 24 0. 22 0. 2 0. 18 0. 16 0. 14 0. 12 0. 1 0. 08 0. 06 0. 04 0. 02 0 Inflow Area=0.046 ac0.26 cfs0.26 EWAM Type III 24-hr 100-year Rainfall=7.32"5064600-PRE Printed 3/20/2024PreparedbyBSCGroup Page40HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 3R: Off-Site (South) Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 024 0. 023 0. 022 0. 021 0. 02 0. 019 0. 018 0. 017 0. 016 0. 015 0. 014 0. 013 0. 012 0. 011 0. 01 0. 009 0. 008 0. 007 0. 006 0. 005 0. 004 0. 003 0. 002 0. 001 0 Inflow Area=0.014 ac 0.02 cfs0.02 Stormwater Report 811 Route 28 South Yarmouth, MA 5.03 PROPOSED WATERSHED PLAN Stormwater Report 811 Route 28 South Yarmouth, MA 5.04 PROPOSED HYDROLOGY CALCULATIONS HYDROCAD™ PRINTOUTS) On-Site 1S CB-1 2S CB-2 3S Building Roof 4S To Basin 5S Off Site (North) 6S Off Site (South) 2R Route 28 3R Off-Site (South) 1P CULTEC R-330XLHD CHAMBER SYSTEM 2P CULTEC R-150XLHD CHAMBER SYSTEM 3P Bioretention Area Routing Diagram for 5064600-POST Prepared by BSC Group, Printed 3/20/2024 HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcat Reach Pond Link PWAM 5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page2HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Rainfall Events Listing Event# Event Name Storm Type Curve Mode Duration hours) B/B Depth inches) AMC 1 2-year Type III 24-hr Default 24.00 1 3.36 2 2 10-year Type III 24-hr Default 24.00 1 4.89 2 3 25-year Type III 24-hr Default 24.00 1 5.85 2 4 50-year Type III 24-hr Default 24.00 1 6.57 2 5 100-year Type III 24-hr Default 24.00 1 7.32 2 PWAM 5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page3HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Area Listing (all nodes) Area acres) CN Description subcatchment-numbers) 0.308 39 >75% Grass cover, Good, HSG A (1S, 2S, 4S, 5S, 6S) 0.254 98 Paved parking, HSG A (1S, 2S, 4S, 5S) 0.104 98 Roofs, HSG A (3S) 0.666 71 TOTAL AREA PWAM 5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page4HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area acres) Soil Group Subcatchment Numbers 0.666 HSG A 1S, 2S, 3S, 4S, 5S, 6S 0.000 HSG B 0.000 HSG C 0.000 HSG D 0.000 Other 0.666 TOTAL AREA PWAM 5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page5HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A acres) HSG-B acres) HSG-C acres) HSG-D acres) Other acres) Total acres) Ground Cover Subcatchment Numbers 0.308 0.000 0.000 0.000 0.000 0.308 >75% Grass cover, Good 1S, 2S, 4S, 5S, 6S 0.254 0.000 0.000 0.000 0.000 0.254 Paved parking 1S, 2S, 4S, 5S 0.104 0.000 0.000 0.000 0.000 0.104 Roofs 3S 0.666 0.000 0.000 0.000 0.000 0.666 TOTAL AREA PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page6HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=4,611 sf 75.10% Impervious Runoff Depth=1.74"Subcatchment 1S: CB-1 Tc=6.0 min CN=83 Runoff=0.22 cfs 0.015 af Runoff Area=12,511 sf 55.12% Impervious Runoff Depth=1.03"Subcatchment 2S: CB-2 Tc=6.0 min CN=72 Runoff=0.32 cfs 0.025 af Runoff Area=4,536 sf 100.00% Impervious Runoff Depth=3.13"Subcatchment 3S: Building Roof Tc=6.0 min CN=98 Runoff=0.34 cfs 0.027 af Runoff Area=5,105 sf 3.39% Impervious Runoff Depth=0.02"Subcatchment 4S: To Basin Flow Length=157' Tc=13.2 min CN=41 Runoff=0.00 cfs 0.000 af Runoff Area=1,233 sf 43.31% Impervious Runoff Depth=0.68"Subcatchment 5S: Off Site (North) Tc=6.0 min CN=65 Runoff=0.02 cfs 0.002 af Runoff Area=1,012 sf 0.00% Impervious Runoff Depth=0.00"Subcatchment 6S: Off Site (South) Tc=6.0 min CN=39 Runoff=0.00 cfs 0.000 af Inflow=0.02 cfs 0.002afReach2R: Route 28 Outflow=0.02 cfs 0.002 af Inflow=0.00 cfs 0.000afReach3R: Off-Site (South) Outflow=0.00 cfs 0.000 af Peak Elev=6.56' Storage=236 cf Inflow=0.54 cfs 0.040afPond1P: CULTEC R-330XLHD CHAMBER Outflow=0.21 cfs 0.040 af Peak Elev=7.64' Storage=162 cf Inflow=0.34 cfs 0.027afPond2P: CULTEC R-150XLHD CHAMBER Outflow=0.12 cfs 0.027 af Peak Elev=9.00' Storage=0 cf Inflow=0.00 cfs 0.000afPond3P: Bioretention Area Outflow=0.00 cfs 0.000 af Total Runoff Area = 0.666 ac Runoff Volume = 0.069 af Average Runoff Depth = 1.24" 46.21% Pervious = 0.308 ac 53.79% Impervious = 0.358 ac PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page7HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 1S: CB-1 Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 24 0. 23 0. 22 0. 21 0. 2 0. 19 0. 18 0. 17 0. 16 0. 15 0. 14 0. 13 0. 12 0. 11 0. 1 0. 09 0. 08 0. 07 0. 06 0. 05 0. 04 0. 03 0. 02 0. 01 0 Type III 24- hr 2-year Rainfall=3. 36"Runoff Area=4,611 sf Runoff Volume=0.015 af Runoff Depth=1. 74"Tc=6.0 min CN= 830.22 PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page8HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 2S: CB-2 Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 36 0. 34 0. 32 0. 3 0. 28 0. 26 0. 24 0. 22 0. 2 0. 18 0. 16 0. 14 0. 12 0. 1 0. 08 0. 06 0. 04 0. 02 0 Type III 24- hr 2-year Rainfall=3. 36"Runoff Area=12,511 sf Runoff Volume=0.025 af Runoff Depth=1. 03"Tc=6.0 min CN= 720.32 PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page9HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 3S: Building Roof Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 38 0. 36 0. 34 0. 32 0. 3 0. 28 0. 26 0. 24 0. 22 0. 2 0. 18 0. 16 0. 14 0. 12 0. 1 0. 08 0. 06 0. 04 0. 02 0 Type III 24- hr 2-year Rainfall=3. 36"Runoff Area=4,536 sf Runoff Volume=0.027 af Runoff Depth=3. 13"Tc=6.0 min CN= 980.34 PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page10HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 4S: To Basin Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0 0 0 0 0 Type III 24- hr 2-year Rainfall=3. 36"Runoff Area=5,105 sf Runoff Volume=0.000 af Runoff Depth=0. 02"Flow Length= 157'Tc=13.2 min CN= 410.00 PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page11HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 5S: Off Site (North) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 02 0. 019 0. 018 0. 017 0. 016 0. 015 0. 014 0. 013 0. 012 0. 011 0. 01 0. 009 0. 008 0. 007 0. 006 0. 005 0. 004 0. 003 0. 002 0. 001 0 Type III 24- hr 2-year Rainfall=3. 36"Runoff Area=1,233 sf Runoff Volume=0.002 af Runoff Depth=0. 68"Tc=6.0 min CN= 65 0.02 PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page12HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 6S: Off Site (South) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Type III 24- hr 2-year Rainfall=3. 36"Runoff Area=1,012 sf Runoff Volume=0.000 af Runoff Depth=0. 00"Tc=6.0 min CN= 390.00 PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page13HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 2R: Route 28 Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 02 0. 019 0. 018 0. 017 0. 016 0. 015 0. 014 0. 013 0. 012 0. 011 0. 01 0. 009 0. 008 0. 007 0. 006 0. 005 0. 004 0. 003 0. 002 0. 001 0 Inflow Area=0.028 ac 0.02 cfs0.02 PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page14HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 3R: Off-Site (South) Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Inflow Area=0.023 ac 0.00 cfs0.00 PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page15HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 1P: CULTEC R-330XLHD CHAMBER SYSTEM - Chamber Wizard Field A Chamber Model = Cultec R-330XLHD (Cultec Recharger® 330XLHD) Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 3 rows 52.0" Wide + 6.0" Spacing = 58.0" C-C Row Spacing 8 Chambers/Row x 7.00' Long +1.50' Row Adjustment = 57.50' Row Length +12.0" End Stone x 2 = 59.50' Base Length 3 Rows x 52.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 16.00' Base Width 6.0" Stone Base + 30.5" Chamber Height + 6.0" Stone Cover = 3.54' Field Height 24 Chambers x 52.2 cf +1.50' Row Adjustment x 7.45 sf x 3 Rows = 1,285.3 cf Chamber Storage 3,371.7 cf Field - 1,285.3 cf Chambers = 2,086.4 cf Stone x 40.0% Voids = 834.5 cf Stone Storage Chamber Storage + Stone Storage = 2,119.8 cf = 0.049 af Overall Storage Efficiency = 62.9% Overall System Size = 59.50' x 16.00' x 3.54' 24 Chambers 124.9 cy Field 77.3 cy Stone PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page16HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 1P: CULTEC R-330XLHD CHAMBER SYSTEM Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 6 0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Inflow Area=0.393 ac Peak Elev=6. 56'Storage=236 cf0.54 cfs0.21 PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page17HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 2P: CULTEC R-150XLHD CHAMBER SYSTEM - Chamber Wizard Field A Chamber Model = Cultec R-150XLHD (Cultec Recharger® 150XLHD) Effective Size= 29.8"W x 18.0"H => 2.65 sf x 10.25'L = 27.2 cf Overall Size= 33.0"W x 18.5"H x 11.00'L with 0.75' Overlap Row Length Adjustment= +0.75' x 2.65 sf x 1 rows 11 Chambers/Row x 10.25' Long +0.75' Row Adjustment = 113.50' Row Length +12.0" End Stone x 2 = 115.50' Base Length 1 Rows x 33.0" Wide + 12.0" Side Stone x 2 = 4.75' Base Width 6.0" Stone Base + 18.5" Chamber Height + 6.0" Stone Cover = 2.54' Field Height 11 Chambers x 27.2 cf +0.75' Row Adjustment x 2.65 sf x 1 Rows = 300.7 cf Chamber Storage 1,394.4 cf Field - 300.7 cf Chambers = 1,093.8 cf Stone x 40.0% Voids = 437.5 cf Stone Storage Chamber Storage + Stone Storage = 738.2 cf = 0.017 af Overall Storage Efficiency = 52.9% Overall System Size = 115.50' x 4.75' x 2.54' 11 Chambers 51.6 cy Field 40.5 cy Stone PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page18HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 2P: CULTEC R-150XLHD CHAMBER SYSTEM Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 38 0. 36 0. 34 0. 32 0. 3 0. 28 0. 26 0. 24 0. 22 0. 2 0. 18 0. 16 0. 14 0. 12 0. 1 0. 08 0. 06 0. 04 0. 02 0 Inflow Area=0.104 ac Peak Elev=7. 64'Storage=162 cf0.34 cfs0.12 PWAM Type III 24-hr 2-year Rainfall=3.36"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page19HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 3P: Bioretention Area Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0 0 0 0 0 Inflow Area=0.117 ac Peak Elev=9. 00'Storage=0 cf 0.00 cfs0.00 PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page20HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=4,611 sf 75.10% Impervious Runoff Depth=3.07"Subcatchment 1S: CB-1 Tc=6.0 min CN=83 Runoff=0.38 cfs 0.027 af Runoff Area=12,511 sf 55.12% Impervious Runoff Depth=2.11"Subcatchment 2S: CB-2 Tc=6.0 min CN=72 Runoff=0.70 cfs 0.051 af Runoff Area=4,536 sf 100.00% Impervious Runoff Depth=4.65"Subcatchment 3S: Building Roof Tc=6.0 min CN=98 Runoff=0.50 cfs 0.040 af Runoff Area=5,105 sf 3.39% Impervious Runoff Depth=0.25"Subcatchment 4S: To Basin Flow Length=157' Tc=13.2 min CN=41 Runoff=0.01 cfs 0.002 af Runoff Area=1,233 sf 43.31% Impervious Runoff Depth=1.58"Subcatchment 5S: Off Site (North) Tc=6.0 min CN=65 Runoff=0.05 cfs 0.004 af Runoff Area=1,012 sf 0.00% Impervious Runoff Depth=0.18"Subcatchment 6S: Off Site (South) Tc=6.0 min CN=39 Runoff=0.00 cfs 0.000 af Inflow=0.05 cfs 0.004afReach2R: Route 28 Outflow=0.05 cfs 0.004 af Inflow=0.00 cfs 0.000afReach3R: Off-Site (South) Outflow=0.00 cfs 0.000 af Peak Elev=7.32' Storage=829 cf Inflow=1.08 cfs 0.078afPond1P: CULTEC R-330XLHD CHAMBER Outflow=0.26 cfs 0.078 af Peak Elev=8.11' Storage=340 cf Inflow=0.50 cfs 0.040afPond2P: CULTEC R-150XLHD CHAMBER Outflow=0.13 cfs 0.040 af Peak Elev=9.05' Storage=8 cf Inflow=0.01 cfs 0.002afPond3P: Bioretention Area Outflow=0.00 cfs 0.002 af Total Runoff Area = 0.666 ac Runoff Volume = 0.125 af Average Runoff Depth = 2.24" 46.21% Pervious = 0.308 ac 53.79% Impervious = 0.358 ac PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page21HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 1S: CB-1 Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 42 0. 4 0. 38 0. 36 0. 34 0. 32 0. 3 0. 28 0. 26 0. 24 0. 22 0. 2 0. 18 0. 16 0. 14 0. 12 0. 1 0. 08 0. 06 0. 04 0. 02 0 Type III 24- hr 10-year Rainfall=4. 89"Runoff Area=4,611 sf Runoff Volume=0.027 af Runoff Depth=3. 07"Tc=6.0 min CN= 830.38 PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page22HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 2S: CB-2 Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 75 0. 7 0. 65 0. 6 0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Type III 24- hr 10-year Rainfall=4. 89"Runoff Area=12,511 sf Runoff Volume=0.051 af Runoff Depth=2. 11"Tc=6.0 min CN= 720.70 PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page23HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 3S: Building Roof Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Type III 24- hr 10-year Rainfall=4. 89"Runoff Area=4,536 sf Runoff Volume=0.040 af Runoff Depth=4. 65"Tc=6.0 min CN= 980.50 PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page24HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 4S: To Basin Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 007 0. 007 0. 006 0. 006 0. 005 0. 005 0. 004 0. 004 0. 003 0. 003 0. 002 0. 002 0. 001 0. 001 0. 000 0 Type III 24- hr 10-year Rainfall=4. 89"Runoff Area=5,105 sf Runoff Volume=0.002 af Runoff Depth=0. 25"Flow Length= 157'Tc=13.2 min CN= 410.01 PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page25HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 5S: Off Site (North) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Type III 24- hr 10-year Rainfall=4. 89"Runoff Area=1,233 sf Runoff Volume=0.004 af Runoff Depth=1. 58"Tc=6.0 min CN= 65 0.05 PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page26HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 6S: Off Site (South) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 001 0. 001 0. 001 0. 001 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0 0 0 Type III 24- hr 10-year Rainfall=4. 89"Runoff Area=1,012 sf Runoff Volume=0.000 af Runoff Depth=0. 18"Tc=6.0 min CN= 390.00 PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page27HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 2R: Route 28 Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Inflow Area=0.028 ac 0.05 cfs0.05 PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page28HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 3R: Off-Site (South) Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 001 0. 001 0. 001 0. 001 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0. 000 0 0 0 Inflow Area=0.023 ac0.00 cfs0.00 PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page29HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 1P: CULTEC R-330XLHD CHAMBER SYSTEM - Chamber Wizard Field A Chamber Model = Cultec R-330XLHD (Cultec Recharger® 330XLHD) Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 3 rows 52.0" Wide + 6.0" Spacing = 58.0" C-C Row Spacing 8 Chambers/Row x 7.00' Long +1.50' Row Adjustment = 57.50' Row Length +12.0" End Stone x 2 = 59.50' Base Length 3 Rows x 52.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 16.00' Base Width 6.0" Stone Base + 30.5" Chamber Height + 6.0" Stone Cover = 3.54' Field Height 24 Chambers x 52.2 cf +1.50' Row Adjustment x 7.45 sf x 3 Rows = 1,285.3 cf Chamber Storage 3,371.7 cf Field - 1,285.3 cf Chambers = 2,086.4 cf Stone x 40.0% Voids = 834.5 cf Stone Storage Chamber Storage + Stone Storage = 2,119.8 cf = 0.049 af Overall Storage Efficiency = 62.9% Overall System Size = 59.50' x 16.00' x 3.54' 24 Chambers 124.9 cy Field 77.3 cy Stone PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page30HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 1P: CULTEC R-330XLHD CHAMBER SYSTEM Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 1 0 Inflow Area=0.393 ac Peak Elev=7. 32'Storage=829 cf 1.08 cfs 0.26 PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page31HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 2P: CULTEC R-150XLHD CHAMBER SYSTEM - Chamber Wizard Field A Chamber Model = Cultec R-150XLHD (Cultec Recharger® 150XLHD) Effective Size= 29.8"W x 18.0"H => 2.65 sf x 10.25'L = 27.2 cf Overall Size= 33.0"W x 18.5"H x 11.00'L with 0.75' Overlap Row Length Adjustment= +0.75' x 2.65 sf x 1 rows 11 Chambers/Row x 10.25' Long +0.75' Row Adjustment = 113.50' Row Length +12.0" End Stone x 2 = 115.50' Base Length 1 Rows x 33.0" Wide + 12.0" Side Stone x 2 = 4.75' Base Width 6.0" Stone Base + 18.5" Chamber Height + 6.0" Stone Cover = 2.54' Field Height 11 Chambers x 27.2 cf +0.75' Row Adjustment x 2.65 sf x 1 Rows = 300.7 cf Chamber Storage 1,394.4 cf Field - 300.7 cf Chambers = 1,093.8 cf Stone x 40.0% Voids = 437.5 cf Stone Storage Chamber Storage + Stone Storage = 738.2 cf = 0.017 af Overall Storage Efficiency = 52.9% Overall System Size = 115.50' x 4.75' x 2.54' 11 Chambers 51.6 cy Field 40.5 cy Stone PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page32HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 2P: CULTEC R-150XLHD CHAMBER SYSTEM Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Inflow Area=0.104 ac Peak Elev=8. 11'Storage=340 cf0.50 cfs0.13 PWAM Type III 24-hr 10-year Rainfall=4.89"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page33HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 3P: Bioretention Area Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 007 0. 007 0. 006 0. 006 0. 005 0. 005 0. 004 0. 004 0. 003 0. 003 0. 002 0. 002 0. 001 0. 001 0. 000 0 Inflow Area=0.117 ac Peak Elev=9. 05'Storage=8 cf0.01 cfs0.00 PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page34HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=4,611 sf 75.10% Impervious Runoff Depth=3.95"Subcatchment 1S: CB-1 Tc=6.0 min CN=83 Runoff=0.49 cfs 0.035 af Runoff Area=12,511 sf 55.12% Impervious Runoff Depth=2.87"Subcatchment 2S: CB-2 Tc=6.0 min CN=72 Runoff=0.96 cfs 0.069 af Runoff Area=4,536 sf 100.00% Impervious Runoff Depth=5.61"Subcatchment 3S: Building Roof Tc=6.0 min CN=98 Runoff=0.60 cfs 0.049 af Runoff Area=5,105 sf 3.39% Impervious Runoff Depth=0.51"Subcatchment 4S: To Basin Flow Length=157' Tc=13.2 min CN=41 Runoff=0.02 cfs 0.005 af Runoff Area=1,233 sf 43.31% Impervious Runoff Depth=2.24"Subcatchment 5S: Off Site (North) Tc=6.0 min CN=65 Runoff=0.07 cfs 0.005 af Runoff Area=1,012 sf 0.00% Impervious Runoff Depth=0.40"Subcatchment 6S: Off Site (South) Tc=6.0 min CN=39 Runoff=0.00 cfs 0.001 af Inflow=0.07 cfs 0.005afReach2R: Route 28 Outflow=0.07 cfs 0.005 af Inflow=0.00 cfs 0.001afReach3R: Off-Site (South) Outflow=0.00 cfs 0.001 af Peak Elev=7.92' Storage=1,277 cf Inflow=1.45 cfs 0.104afPond1P: CULTEC R-330XLHD CHAMBER Outflow=0.29 cfs 0.104 af Peak Elev=8.45' Storage=461 cf Inflow=0.60 cfs 0.049afPond2P: CULTEC R-150XLHD CHAMBER Outflow=0.14 cfs 0.049 af Peak Elev=9.24' Storage=44 cf Inflow=0.02 cfs 0.005afPond3P: Bioretention Area Outflow=0.01 cfs 0.005 af Total Runoff Area = 0.666 ac Runoff Volume = 0.163 af Average Runoff Depth = 2.94" 46.21% Pervious = 0.308 ac 53.79% Impervious = 0.358 ac PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page35HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 1S: CB-1 Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Type III 24- hr 25-year Rainfall=5. 85"Runoff Area=4,611 sf Runoff Volume=0.035 af Runoff Depth=3. 95"Tc=6.0 min CN= 830.49 PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page36HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 2S: CB-2 Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 1 0 Type III 24- hr 25-year Rainfall=5. 85"Runoff Area=12,511 sf Runoff Volume=0.069 af Runoff Depth=2. 87"Tc=6.0 min CN= 72 0.96 PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page37HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 3S: Building Roof Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 65 0. 6 0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Type III 24- hr 25-year Rainfall=5. 85"Runoff Area=4,536 sf Runoff Volume=0.049 af Runoff Depth=5. 61"Tc=6.0 min CN= 980.60 PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page38HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 4S: To Basin Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 026 0. 024 0. 022 0. 02 0. 018 0. 016 0. 014 0. 012 0. 01 0. 008 0. 006 0. 004 0. 002 0 Type III 24- hr 25-year Rainfall=5. 85"Runoff Area=5,105 sf Runoff Volume=0.005 af Runoff Depth=0. 51"Flow Length= 157'Tc=13.2 min CN= 410.02 PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page39HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 5S: Off Site (North) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 08 0. 075 0. 07 0. 065 0. 06 0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Type III 24- hr 25-year Rainfall=5. 85"Runoff Area=1,233 sf Runoff Volume=0.005 af Runoff Depth=2. 24"Tc=6.0 min CN= 65 0.07 PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page40HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 6S: Off Site (South) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 004 0. 004 0. 003 0. 003 0. 003 0. 003 0. 003 0. 002 0. 002 0. 002 0. 002 0. 002 0. 001 0. 001 0. 001 0. 001 0. 001 0. 000 0. 000 0 Type III 24- hr 25-year Rainfall=5. 85"Runoff Area=1,012 sf Runoff Volume=0.001 af Runoff Depth=0. 40"Tc=6.0 min CN= 39 0.00 PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page41HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 2R: Route 28 Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 08 0. 075 0. 07 0. 065 0. 06 0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Inflow Area=0.028 ac 0.07 cfs0.07 PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page42HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 3R: Off-Site (South) Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 004 0. 004 0. 003 0. 003 0. 003 0. 003 0. 003 0. 002 0. 002 0. 002 0. 002 0. 002 0. 001 0. 001 0. 001 0. 001 0. 001 0. 000 0. 000 0 Inflow Area=0.023 ac 0.00 cfs0.00 PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page43HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 1P: CULTEC R-330XLHD CHAMBER SYSTEM - Chamber Wizard Field A Chamber Model = Cultec R-330XLHD (Cultec Recharger® 330XLHD) Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 3 rows 52.0" Wide + 6.0" Spacing = 58.0" C-C Row Spacing 8 Chambers/Row x 7.00' Long +1.50' Row Adjustment = 57.50' Row Length +12.0" End Stone x 2 = 59.50' Base Length 3 Rows x 52.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 16.00' Base Width 6.0" Stone Base + 30.5" Chamber Height + 6.0" Stone Cover = 3.54' Field Height 24 Chambers x 52.2 cf +1.50' Row Adjustment x 7.45 sf x 3 Rows = 1,285.3 cf Chamber Storage 3,371.7 cf Field - 1,285.3 cf Chambers = 2,086.4 cf Stone x 40.0% Voids = 834.5 cf Stone Storage Chamber Storage + Stone Storage = 2,119.8 cf = 0.049 af Overall Storage Efficiency = 62.9% Overall System Size = 59.50' x 16.00' x 3.54' 24 Chambers 124.9 cy Field 77.3 cy Stone PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page44HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 1P: CULTEC R-330XLHD CHAMBER SYSTEM Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 1 0 Inflow Area=0.393 ac Peak Elev=7. 92'Storage=1,277 cf 1.45 cfs 0.29 PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page45HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 2P: CULTEC R-150XLHD CHAMBER SYSTEM - Chamber Wizard Field A Chamber Model = Cultec R-150XLHD (Cultec Recharger® 150XLHD) Effective Size= 29.8"W x 18.0"H => 2.65 sf x 10.25'L = 27.2 cf Overall Size= 33.0"W x 18.5"H x 11.00'L with 0.75' Overlap Row Length Adjustment= +0.75' x 2.65 sf x 1 rows 11 Chambers/Row x 10.25' Long +0.75' Row Adjustment = 113.50' Row Length +12.0" End Stone x 2 = 115.50' Base Length 1 Rows x 33.0" Wide + 12.0" Side Stone x 2 = 4.75' Base Width 6.0" Stone Base + 18.5" Chamber Height + 6.0" Stone Cover = 2.54' Field Height 11 Chambers x 27.2 cf +0.75' Row Adjustment x 2.65 sf x 1 Rows = 300.7 cf Chamber Storage 1,394.4 cf Field - 300.7 cf Chambers = 1,093.8 cf Stone x 40.0% Voids = 437.5 cf Stone Storage Chamber Storage + Stone Storage = 738.2 cf = 0.017 af Overall Storage Efficiency = 52.9% Overall System Size = 115.50' x 4.75' x 2.54' 11 Chambers 51.6 cy Field 40.5 cy Stone PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page46HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 2P: CULTEC R-150XLHD CHAMBER SYSTEM Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 65 0. 6 0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Inflow Area=0.104 ac Peak Elev=8. 45'Storage=461 cf0.60 cfs0.14 PWAM Type III 24-hr 25-year Rainfall=5.85"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page47HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 3P: Bioretention Area Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 026 0. 024 0. 022 0. 02 0. 018 0. 016 0. 014 0. 012 0. 01 0. 008 0. 006 0. 004 0. 002 0 Inflow Area=0.117 ac Peak Elev=9. 24'Storage=44 cf 0.02 cfs0.01 PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page48HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=4,611 sf 75.10% Impervious Runoff Depth=4.62"Subcatchment 1S: CB-1 Tc=6.0 min CN=83 Runoff=0.56 cfs 0.041 af Runoff Area=12,511 sf 55.12% Impervious Runoff Depth=3.47"Subcatchment 2S: CB-2 Tc=6.0 min CN=72 Runoff=1.17 cfs 0.083 af Runoff Area=4,536 sf 100.00% Impervious Runoff Depth=6.33"Subcatchment 3S: Building Roof Tc=6.0 min CN=98 Runoff=0.67 cfs 0.055 af Runoff Area=5,105 sf 3.39% Impervious Runoff Depth=0.75"Subcatchment 4S: To Basin Flow Length=157' Tc=13.2 min CN=41 Runoff=0.04 cfs 0.007 af Runoff Area=1,233 sf 43.31% Impervious Runoff Depth=2.77"Subcatchment 5S: Off Site (North) Tc=6.0 min CN=65 Runoff=0.09 cfs 0.007 af Runoff Area=1,012 sf 0.00% Impervious Runoff Depth=0.62"Subcatchment 6S: Off Site (South) Tc=6.0 min CN=39 Runoff=0.01 cfs 0.001 af Inflow=0.09 cfs 0.007afReach2R: Route 28 Outflow=0.09 cfs 0.007 af Inflow=0.01 cfs 0.001afReach3R: Off-Site (South) Outflow=0.01 cfs 0.001 af Peak Elev=8.45' Storage=1,631 cf Inflow=1.73 cfs 0.124afPond1P: CULTEC R-330XLHD CHAMBER Outflow=0.32 cfs 0.124 af Peak Elev=8.74' Storage=553 cf Inflow=0.67 cfs 0.055afPond2P: CULTEC R-150XLHD CHAMBER Outflow=0.15 cfs 0.055 af Peak Elev=9.45' Storage=81 cf Inflow=0.04 cfs 0.007afPond3P: Bioretention Area Outflow=0.01 cfs 0.007 af Total Runoff Area = 0.666 ac Runoff Volume = 0.194 af Average Runoff Depth = 3.49" 46.21% Pervious = 0.308 ac 53.79% Impervious = 0.358 ac PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page49HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 1S: CB-1 Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 6 0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Type III 24- hr 50-year Rainfall=6. 57"Runoff Area=4,611 sf Runoff Volume=0.041 af Runoff Depth=4. 62"Tc=6.0 min CN= 830.56 PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page50HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 2S: CB-2 Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 1 0 Type III 24- hr 50-year Rainfall=6. 57"Runoff Area=12,511 sf Runoff Volume=0.083 af Runoff Depth=3. 47"Tc=6.0 min CN= 72 1.17 PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page51HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 3S: Building Roof Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 75 0. 7 0. 65 0. 6 0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Type III 24- hr 50-year Rainfall=6. 57"Runoff Area=4,536 sf Runoff Volume=0.055 af Runoff Depth=6. 33"Tc=6.0 min CN= 980.67 PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page52HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 4S: To Basin Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 048 0. 046 0. 044 0. 042 0. 04 0. 038 0. 036 0. 034 0. 032 0. 03 0. 028 0. 026 0. 024 0. 022 0. 02 0. 018 0. 016 0. 014 0. 012 0. 01 0. 008 0. 006 0. 004 0. 002 0 Type III 24- hr 50-year Rainfall=6. 57"Runoff Area=5,105 sf Runoff Volume=0.007 af Runoff Depth=0. 75"Flow Length= 157'Tc=13.2 min CN= 41 0.04 PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page53HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 5S: Off Site (North) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 1 0. 095 0. 09 0. 085 0. 08 0. 075 0. 07 0. 065 0. 06 0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Type III 24- hr 50-year Rainfall=6. 57"Runoff Area=1,233 sf Runoff Volume=0.007 af Runoff Depth=2. 77"Tc=6.0 min CN= 650.09 PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page54HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 6S: Off Site (South) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 007 0. 007 0. 006 0. 006 0. 005 0. 005 0. 004 0. 004 0. 003 0. 003 0. 002 0. 002 0. 001 0. 001 0. 000 0 Type III 24- hr 50-year Rainfall=6. 57"Runoff Area=1,012 sf Runoff Volume=0.001 af Runoff Depth=0. 62"Tc=6.0 min CN= 390.01 PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page55HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 2R: Route 28 Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 1 0. 095 0. 09 0. 085 0. 08 0. 075 0. 07 0. 065 0. 06 0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Inflow Area=0.028 ac0.09 cfs0.09 PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page56HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 3R: Off-Site (South) Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 007 0. 007 0. 006 0. 006 0. 005 0. 005 0. 004 0. 004 0. 003 0. 003 0. 002 0. 002 0. 001 0. 001 0. 000 0 Inflow Area=0.023 ac0.01 cfs0.01 PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page57HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 1P: CULTEC R-330XLHD CHAMBER SYSTEM - Chamber Wizard Field A Chamber Model = Cultec R-330XLHD (Cultec Recharger® 330XLHD) Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 3 rows 52.0" Wide + 6.0" Spacing = 58.0" C-C Row Spacing 8 Chambers/Row x 7.00' Long +1.50' Row Adjustment = 57.50' Row Length +12.0" End Stone x 2 = 59.50' Base Length 3 Rows x 52.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 16.00' Base Width 6.0" Stone Base + 30.5" Chamber Height + 6.0" Stone Cover = 3.54' Field Height 24 Chambers x 52.2 cf +1.50' Row Adjustment x 7.45 sf x 3 Rows = 1,285.3 cf Chamber Storage 3,371.7 cf Field - 1,285.3 cf Chambers = 2,086.4 cf Stone x 40.0% Voids = 834.5 cf Stone Storage Chamber Storage + Stone Storage = 2,119.8 cf = 0.049 af Overall Storage Efficiency = 62.9% Overall System Size = 59.50' x 16.00' x 3.54' 24 Chambers 124.9 cy Field 77.3 cy Stone PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page58HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 1P: CULTEC R-330XLHD CHAMBER SYSTEM Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 1 0 Inflow Area=0.393 ac Peak Elev=8. 45'Storage=1,631 cf 1.73 cfs0.32 PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page59HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 2P: CULTEC R-150XLHD CHAMBER SYSTEM - Chamber Wizard Field A Chamber Model = Cultec R-150XLHD (Cultec Recharger® 150XLHD) Effective Size= 29.8"W x 18.0"H => 2.65 sf x 10.25'L = 27.2 cf Overall Size= 33.0"W x 18.5"H x 11.00'L with 0.75' Overlap Row Length Adjustment= +0.75' x 2.65 sf x 1 rows 11 Chambers/Row x 10.25' Long +0.75' Row Adjustment = 113.50' Row Length +12.0" End Stone x 2 = 115.50' Base Length 1 Rows x 33.0" Wide + 12.0" Side Stone x 2 = 4.75' Base Width 6.0" Stone Base + 18.5" Chamber Height + 6.0" Stone Cover = 2.54' Field Height 11 Chambers x 27.2 cf +0.75' Row Adjustment x 2.65 sf x 1 Rows = 300.7 cf Chamber Storage 1,394.4 cf Field - 300.7 cf Chambers = 1,093.8 cf Stone x 40.0% Voids = 437.5 cf Stone Storage Chamber Storage + Stone Storage = 738.2 cf = 0.017 af Overall Storage Efficiency = 52.9% Overall System Size = 115.50' x 4.75' x 2.54' 11 Chambers 51.6 cy Field 40.5 cy Stone PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page60HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 2P: CULTEC R-150XLHD CHAMBER SYSTEM Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 75 0. 7 0. 65 0. 6 0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Inflow Area=0.104 ac Peak Elev=8. 74'Storage=553 cf0.67 cfs0.15 PWAM Type III 24-hr 50-year Rainfall=6.57"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page61HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 3P: Bioretention Area Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 048 0. 046 0. 044 0. 042 0. 04 0. 038 0. 036 0. 034 0. 032 0. 03 0. 028 0. 026 0. 024 0. 022 0. 02 0. 018 0. 016 0. 014 0. 012 0. 01 0. 008 0. 006 0. 004 0. 002 0 Inflow Area=0.117 ac Peak Elev=9. 45'Storage=81 cf0.04 cfs0.01 PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page62HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Time span=0.00-36.00 hrs, dt=0.01 hrs, 3601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=4,611 sf 75.10% Impervious Runoff Depth=5.33"Subcatchment 1S: CB-1 Tc=6.0 min CN=83 Runoff=0.65 cfs 0.047 af Runoff Area=12,511 sf 55.12% Impervious Runoff Depth=4.10"Subcatchment 2S: CB-2 Tc=6.0 min CN=72 Runoff=1.38 cfs 0.098 af Runoff Area=4,536 sf 100.00% Impervious Runoff Depth=7.08"Subcatchment 3S: Building Roof Tc=6.0 min CN=98 Runoff=0.75 cfs 0.061 af Runoff Area=5,105 sf 3.39% Impervious Runoff Depth=1.05"Subcatchment 4S: To Basin Flow Length=157' Tc=13.2 min CN=41 Runoff=0.07 cfs 0.010 af Runoff Area=1,233 sf 43.31% Impervious Runoff Depth=3.35"Subcatchment 5S: Off Site (North) Tc=6.0 min CN=65 Runoff=0.11 cfs 0.008 af Runoff Area=1,012 sf 0.00% Impervious Runoff Depth=0.89"Subcatchment 6S: Off Site (South) Tc=6.0 min CN=39 Runoff=0.01 cfs 0.002 af Inflow=0.11 cfs 0.008afReach2R: Route 28 Outflow=0.11 cfs 0.008 af Inflow=0.01 cfs 0.002afReach3R: Off-Site (South) Outflow=0.01 cfs 0.002 af Peak Elev=9.23' Storage=2,001 cf Inflow=2.03 cfs 0.145afPond1P: CULTEC R-330XLHD CHAMBER Outflow=0.36 cfs 0.145 af Peak Elev=9.14' Storage=649 cf Inflow=0.75 cfs 0.061afPond2P: CULTEC R-150XLHD CHAMBER Outflow=0.16 cfs 0.061 af Peak Elev=9.70' Storage=127 cf Inflow=0.07 cfs 0.010afPond3P: Bioretention Area Outflow=0.02 cfs 0.010 af Total Runoff Area = 0.666 ac Runoff Volume = 0.227 af Average Runoff Depth = 4.08" 46.21% Pervious = 0.308 ac 53.79% Impervious = 0.358 ac PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page63HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 1S: CB-1 Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 7 0. 65 0. 6 0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Type III 24- hr 100-year Rainfall=7. 32"Runoff Area=4,611 sf Runoff Volume=0.047 af Runoff Depth=5. 33"Tc=6.0 min CN= 830.65 PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page64HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 2S: CB-2 Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 1 0 Type III 24- hr 100-year Rainfall=7. 32"Runoff Area=12,511 sf Runoff Volume=0.098 af Runoff Depth=4. 10"Tc=6.0 min CN= 72 1.38 PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page65HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 3S: Building Roof Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 8 0. 75 0. 7 0. 65 0. 6 0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Type III 24- hr 100-year Rainfall=7. 32"Runoff Area=4,536 sf Runoff Volume=0.061 af Runoff Depth=7. 08"Tc=6.0 min CN= 980.75 PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page66HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 4S: To Basin Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 08 0. 075 0. 07 0. 065 0. 06 0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Type III 24- hr 100-year Rainfall=7. 32"Runoff Area=5,105 sf Runoff Volume=0.010 af Runoff Depth=1. 05"Flow Length= 157'Tc=13.2 min CN= 410.07 PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page67HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 5S: Off Site (North) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 12 0. 115 0. 11 0. 105 0. 1 0. 095 0. 09 0. 085 0. 08 0. 075 0. 07 0. 065 0. 06 0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Type III 24- hr 100-year Rainfall=7. 32"Runoff Area=1,233 sf Runoff Volume=0.008 af Runoff Depth=3. 35"Tc=6.0 min CN= 650.11 PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page68HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Subcatchment 6S: Off Site (South) Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 014 0. 013 0. 012 0. 011 0. 01 0. 009 0. 008 0. 007 0. 006 0. 005 0. 004 0. 003 0. 002 0. 001 0 Type III 24- hr 100-year Rainfall=7. 32"Runoff Area=1,012 sf Runoff Volume=0.002 af Runoff Depth=0. 89"Tc=6.0 min CN= 39 0.01 PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page69HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 2R: Route 28 Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 12 0. 115 0. 11 0. 105 0. 1 0. 095 0. 09 0. 085 0. 08 0. 075 0. 07 0. 065 0. 06 0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Inflow Area=0.028 ac0.11 cfs0.11 PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page70HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Reach 3R: Off-Site (South) Inflow Outflow Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 014 0. 013 0. 012 0. 011 0. 01 0. 009 0. 008 0. 007 0. 006 0. 005 0. 004 0. 003 0. 002 0. 001 0 Inflow Area=0.023 ac 0.01 cfs0.01 PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page71HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 1P: CULTEC R-330XLHD CHAMBER SYSTEM - Chamber Wizard Field A Chamber Model = Cultec R-330XLHD (Cultec Recharger® 330XLHD) Effective Size= 47.8"W x 30.0"H => 7.45 sf x 7.00'L = 52.2 cf Overall Size= 52.0"W x 30.5"H x 8.50'L with 1.50' Overlap Row Length Adjustment= +1.50' x 7.45 sf x 3 rows 52.0" Wide + 6.0" Spacing = 58.0" C-C Row Spacing 8 Chambers/Row x 7.00' Long +1.50' Row Adjustment = 57.50' Row Length +12.0" End Stone x 2 = 59.50' Base Length 3 Rows x 52.0" Wide + 6.0" Spacing x 2 + 12.0" Side Stone x 2 = 16.00' Base Width 6.0" Stone Base + 30.5" Chamber Height + 6.0" Stone Cover = 3.54' Field Height 24 Chambers x 52.2 cf +1.50' Row Adjustment x 7.45 sf x 3 Rows = 1,285.3 cf Chamber Storage 3,371.7 cf Field - 1,285.3 cf Chambers = 2,086.4 cf Stone x 40.0% Voids = 834.5 cf Stone Storage Chamber Storage + Stone Storage = 2,119.8 cf = 0.049 af Overall Storage Efficiency = 62.9% Overall System Size = 59.50' x 16.00' x 3.54' 24 Chambers 124.9 cy Field 77.3 cy Stone PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page72HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 1P: CULTEC R-330XLHD CHAMBER SYSTEM Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs) 2 1 0 Inflow Area=0.393 ac Peak Elev=9. 23'Storage=2,001 cf 2.03 cfs0.36 PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page73HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 2P: CULTEC R-150XLHD CHAMBER SYSTEM - Chamber Wizard Field A Chamber Model = Cultec R-150XLHD (Cultec Recharger® 150XLHD) Effective Size= 29.8"W x 18.0"H => 2.65 sf x 10.25'L = 27.2 cf Overall Size= 33.0"W x 18.5"H x 11.00'L with 0.75' Overlap Row Length Adjustment= +0.75' x 2.65 sf x 1 rows 11 Chambers/Row x 10.25' Long +0.75' Row Adjustment = 113.50' Row Length +12.0" End Stone x 2 = 115.50' Base Length 1 Rows x 33.0" Wide + 12.0" Side Stone x 2 = 4.75' Base Width 6.0" Stone Base + 18.5" Chamber Height + 6.0" Stone Cover = 2.54' Field Height 11 Chambers x 27.2 cf +0.75' Row Adjustment x 2.65 sf x 1 Rows = 300.7 cf Chamber Storage 1,394.4 cf Field - 300.7 cf Chambers = 1,093.8 cf Stone x 40.0% Voids = 437.5 cf Stone Storage Chamber Storage + Stone Storage = 738.2 cf = 0.017 af Overall Storage Efficiency = 52.9% Overall System Size = 115.50' x 4.75' x 2.54' 11 Chambers 51.6 cy Field 40.5 cy Stone PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page74HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 2P: CULTEC R-150XLHD CHAMBER SYSTEM Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 8 0. 75 0. 7 0. 65 0. 6 0. 55 0. 5 0. 45 0. 4 0. 35 0. 3 0. 25 0. 2 0. 15 0. 1 0. 05 0 Inflow Area=0.104 ac Peak Elev=9. 14'Storage=649 cf0.75 cfs0.16 PWAM Type III 24-hr 100-year Rainfall=7.32"5064600-POST Printed 3/20/2024PreparedbyBSCGroup Page75HydroCAD® 10.20-3g s/n 00904 © 2023 HydroCAD Software Solutions LLC Pond 3P: Bioretention Area Inflow Discarded Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow ( cfs)0. 08 0. 075 0. 07 0. 065 0. 06 0. 055 0. 05 0. 045 0. 04 0. 035 0. 03 0. 025 0. 02 0. 015 0. 01 0. 005 0 Inflow Area=0.117 ac Peak Elev=9. 70'Storage=127 cf0.07 cfs0.02 Stormwater Report 811 Route 28 South Yarmouth, MA SECTION 6.0 ADDITIONAL DRAINAGE CALCULATIONS Stormwater Report 811 Route 28 South Yarmouth, MA 6.01 TSS REMOVAL CALCULATIONS TSS Removal Calculation Worksheet Location: South Yarmouth, MA Project: 811 Route 28 Prepared By: M. Morrison Date: 3/20/2024 AREA 1 Subcatchment 1S Total Impervious Area, Acres= 0.079 A B C D E BMP TSS Removal Rate Starting TSS Load* Amount Removed (BxC) Remaining Load C-D) Deep Sump and Hooded Catchbasins 0.25 1.00 0.25 0.75 Infiltration Basin 0.8 0.75 0.60 0.15 TSS Removal =0.85 AREA 2 Subcatchment 2S Total Impervious Area, Acres= 0.158 A B C D E BMP TSS Removal Rate Starting TSS Load* Amount Removed (BxC) Remaining Load C-D) Deep Sump and Hooded Catchbasins 0.25 1.00 0.25 0.75 Infiltration Basin 0.8 0.75 0.60 0.15 TSS Removal =0.85 AREA 3 Subcatchment 3S Total Impervious Area, Acres= 0.104 A B C D E BMP TSS Removal Rate Starting TSS Load* Amount Removed (BxC) Remaining Load C-D) Infiltration Basin 0.8 1.00 0.80 0.20 TSS Removal =0.80 AREA 4 Subcatchment 5S Total Impervious Area, Acres= 0.012 A B C D E Prj\2290800\Design\Drainage\2024-01-18 TSS-REMOVAL Weighted Ave.xls 3/20/2024 9:05 AM BMP TSS Removal Rate Starting TSS Load* Amount Removed (BxC) Remaining Load C-D) NONE 1.00 1.00 TSS Removal = WEIGHTED AVERAGE Total Site TSS Removal = [(0.370*0.87)+(0.397*0.80)] / (0.370+0.397) Total Site TSS Removal =0.81 Equals remaining load from previous BMP (E) Prj\2290800\Design\Drainage\2024-01-18 TSS-REMOVAL Weighted Ave.xls 3/20/2024 9:05 AM Stormwater Report 811 Route 28 South Yarmouth, MA 6.02 GROUNDWATER RECHARGE VOLUME CALCULATIONS Stormwater Report 811 Route 28 South Yarmouth, MA Required Recharge Volume Rv = F x Impervious Area Where: Rv = Recharge Volume F=Target Depth Factor associated with each Hydrologic Soil Group F=0.60-inch for Soil Type A) Impervious Area = Proposed Pavement and Rooftop area on-site 0.60 12 15,594 = Rv = 780 cf (required recharge volume) Storage Provided o Underground Infiltration System 01 = 2,120 cubic feet provided. o Underground Infiltration System 02 = 738 cubic feet provided. o Infiltration Basin = 398 cubic feet provided. Total Storage = 3,256 cubic feet provided. Stormwater Report 811 Route 28 South Yarmouth, MA Drawdown Within 72-Hours Pond 1P Rv = Recharge Volume, cu.ft. (see above) K = Saturated Hydraulic Conductivity, in/hr (from Rawls Table) Bottom Area = Area of Infiltration System Bottom, sq.ft. Pond 1P Rv = Recharge Volume, 518 cu.ft. (see HydroCAD) K = Saturated Hydraulic Conductivity, in/hr (from Rawls Table) Bottom Area = Area of Infiltration System Bottom, sq.ft. 518 &’.. 0.689 /ℎ* 952 +..= 0. 79 ℎ-’* o 0.79 hours < 72 hours Pond 2P Rv = Recharge Volume, 227 cu.ft. ( see HydroCAD) K = Saturated Hydraulic Conductivity, in/hr (from Rawls Table) Bottom Area = Area of Infiltration System Bottom, sq. ft. 227 &’..0. 689 /ℎ* 548 +..= 0.60 ℎ-’* o 0. Stormwater Report 811 Route 28 South Yarmouth, MA Pond 3P (Bioretention Area) Rv = Recharge Volume, 182 cu.ft. (see HydroCAD) K = Saturated Hydraulic Conductivity, in/hr (from Rawls Table) Bottom Area = Area of Infiltration System Bottom, sq.ft. 182 &’.. 0.689 /ℎ* 56 +..= 4. 71 ℎ-’* o 4.71 hours < Stormwater Report 811 Route 28 South Yarmouth, MA 6.03 WATER QUALITY VOLUME CALCULATIONS Stormwater Report 811 Route 28 South Yarmouth, MA Water Quality Volume Calculation VWQ = (DWQ/12 inches/foot) * (AIMP square feet) VWQ = Required Water Quality Volume (in cubic feet) DWQ = Water Quality Depth: 0.5-inch AIMP = Total Impervious Area (in acres) used for driveways, parking, etc. Underground Infiltration Systems and Bio-Retention Areas AIMP = 15,594 sq.ft. VWQ = (0.5 inches/12 inches/foot) * (15,594 sq.ft.) VWQ = 650 cubic feet (required volume), provided volume = 3,256 cubic feet in Underground Infiltration Systems and Bioretention Area (refer to the HydroCAD storage tables provided in groundwater recharge section). Stormwater Report 811 Route 28 South Yarmouth, MA 6.04 ILLICIT DISCHARGE COMPLIANCE STATEMENT Stormwater Report 811 Route 28 South Yarmouth, MA Illicit Discharge Compliance Statement This statement is to document that, to the best of my knowledge and belief, there are no and will be no illicit discharges to the stormwater management systems or protected wetland resource areas residential development at 811 Route 28 in South Yarmouth, Massachusetts. Authorized Signature/Title Date Stormwater Report 811 Route 28 South Yarmouth, MA APPENDIX A USGS LOCUS MAP Stormwater Report 811 Route 28 South Yarmouth, MA APPENDIX B FEMA MAP NationalFloodHazardLayerFIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEEFISREPORTFORDETAILEDLEGENDANDINDEXMAPFORFIRMPANELLAYOUT SPECIAL FLOOD HAZARDAREAS Without BaseFloodElevation (BFE) ZoneA, V, A99 WithBFEorDepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% AnnualChanceFloodHazard, Areas of1% annual chancefloodwithaverage depthlessthanonefootorwithdrainage areasoflessthanonesquaremileZoneX FutureConditions 1% Annual ChanceFloodHazardZone X AreawithReducedFloodRiskdueto Levee. SeeNotes.ZoneX AreawithFloodRiskduetoLeveeZoneD NOSCREEN AreaofMinimal FloodHazard ZoneX AreaofUndetermined FloodHazardZone D Channel, Culvert, orStormSewer Levee, Dike, orFloodwall CrossSectionswith1% AnnualChance 17.5 WaterSurfaceElevation Coastal Transect Coastal Transect Baseline ProfileBaseline Hydrographic Feature BaseFloodElevationLine (BFE) EffectiveLOMRs LimitofStudy Jurisdiction Boundary DigitalDataAvailable NoDigitalDataAvailable Unmapped Thismapcomplies withFEMA'sstandards fortheuseof digital floodmapsifitisnotvoidasdescribedbelow. Thebasemapshowncomplies withFEMA'sbasemap accuracy standards Thefloodhazardinformation isderiveddirectlyfromthe authoritative NFHLwebservicesprovidedbyFEMA. Thismap wasexportedon1/18/2024at9:01PManddoesnot reflectchangesoramendments subsequent tothisdateand time. TheNFHLandeffectiveinformation maychangeor becomesupersededbynewdataovertime. Thismapimageisvoidiftheoneormoreofthefollowingmap elementsdonotappear: basemapimagery, floodzonelabels, legend, scalebar, mapcreationdate, community identifiers, FIRMpanelnumber, andFIRMeffectivedate. Mapimagesfor unmapped andunmodernized areascannotbeusedfor regulatory purposes. Legend OTHERAREASOF FLOODHAZARD OTHERAREAS GENERAL STRUCTURES OTHER FEATURES MAPPANELS 8 B 20.2 Thepindisplayedonthemapisanapproximate pointselectedbytheuseranddoesnotrepresent anauthoritative property location. 1:6,000 70°13'14"W41°39'14"N 70°12'37"W41°38'47"N BasemapImagerySource: USGSNational Map2023 Stormwater Report 811 Route 28 South Yarmouth, MA APPENDIX C WEB SOIL SURVEY Hydrologic Soil Group—Barnstable County, Massachusetts Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 1/18/2024 Page 1 of44611690461171046117304611750461177046117904611810461183046116904611710461173046117504611770461179046118104611830398640398660398680398700398720398740398760398780398800398820398840398860398640398660398680398700398720398740398760398780398800398820398840398860 41° 39' 6'' N 70° 13' 2'' W41° 39' 6'' N70° 12' 52'' W41° 39' 1'' N 70° 13' 2'' W41° 39' 1'' N 70° 12' 52'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 19N WGS84 0 50 100 200 300 Feet 015 306090 Meters MapScale: 1:1, 090 if printed on A landscape (11" x 8. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:25,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Barnstable County, Massachusetts Survey Area Data: Version 20, Sep 12, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 10, 2022—Jun 30, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Hydrologic Soil Group—Barnstable County, Massachusetts Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 1/18/2024 Page 2 of 4 Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 252A Carver coarse sand, 0 to 3 percent slopes A 4.2 100.0% Totals for Area of Interest 4.2 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Hydrologic Soil Group—Barnstable County, Massachusetts Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 1/18/2024 Page 3 of 4 Tie-break Rule: Higher Hydrologic Soil Group—Barnstable County, Massachusetts Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 1/18/2024 Page 4 of 4