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Stormwater Report COMPLETE - Signed Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page i TABLE OF CONTENTS SECTION PAGE NO. 1. INTRODUCTION............................................................................................................................................... 1-1 2. SITE DESCRIPTION ....................................................................................................................................... 2-1 2.1 Predevelopment Conditions ........................................................................................................ 2-1 2.2 Resource Areas ................................................................................................................................ 2-1 2.2.1 Floodplain ........................................................................................................................................ 2-1 2.2.2 Natural Heritage and Endangered Species Program ........................................................... 2-1 2.3 Soils .................................................................................................................................................... 2-2 2.4 Post Development Conditions ..................................................................................................... 2-2 3. STORMWATER MANAGEMENT SYSTEM ........................................................................................... 3-1 3.1 Drainage Calculations .................................................................................................................. 3-1 3.1.1 Design Points ................................................................................................................................... 3-2 3.1.2 Pre-Development Hydrology ....................................................................................................... 3-2 3.1.3 Post-Development Hydrology...................................................................................................... 3-2 3.1.4 Peak Discharge Rates .................................................................................................................... 3-2 3.2 Hydraulic Analysis .......................................................................................................................... 3-3 3.3 MassDEP Stormwater Management Standards ...................................................................... 3-3 3.4 Stormwater Best Management Practices .................................................................................. 3-6 3.4.1 Bio-Retention Areas ....................................................................................................................... 3-6 3.4.2 Proprietary Sedimentation Devices ............................................................................................ 3-6 3.5 Protection of Stormwater Best Management Practices during Construction .................. 3-6 3.6 Inspection and Maintenance of Stormwater Best Management Practices ...................... 3-7 3.7 Illicit Discharge Compliance Statement ................................................................................... 3-7 3.8 Northampton DPW Inspection Schedule Checklist ............................................................... 3-7 4. CONCLUSION ................................................................................................................................................... 4-1 List of Tables Table Page No. Table 2.4: Hydrologic Soil Group Classification ....................................................................... 2-2 Table 3.1: Design Rainfall Data ............................................................................................... 3-1 Table 3.1.4 Pre- and Post-Development Peak Discharge Rates ................................................. 3-2 Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page ii List of Figures Figure Figure 1: Site Locus – USGS Map Figure 2: FEMA Flood Map Figure 3: NHESP Map Figure 4: Pre-Development Watershed Plan Figure 5: Post-Development Watershed Plan Figure 6: Inlet Area Appendices APPENDIX A: CHECKLIST FOR STORMWATER REPORT APPENDIX B: SOILS INFORMATION APPENDIX C: PRE- AND POST- DEVELOPMENT HYDROLOGIC ANALYSIS (2, 10, & 100 YEAR STORM EVENTS) APPENDIX D: HYDRAULIC ANALYSIS APPENDIX E: MASSDEP CALCULATIONS APPENDIX F: CONSTRUCTION PERIOD EROSION CONTROL PLAN APPENDIX G: LONG-TERM OPERATION AND MAINTENANCE PLAN APPENDIX H: ILLICIT DISCHARGE COMPLIANCE STATEMENT APPENDIX I: NORTHAMPTON DPW INSPECTION SCHEDULE Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 1-1 1. INTRODUCTION The applicant, American Dream Realty, is proposing to redevelop a property located at 55 Damon Road in Northampton, Massachusetts. Said property is further described as parcel(s) 18D-026- 001 & 18D-065-001 by the City of Northampton Assessor’s Office. For the purposes of this report said parcel(s) will be herein referred to as the “property” or the “site”. The site of proposed development has been historically developed. Currently, the site is the location of an automobile storage area. Prior to this use the property was the home of the Lia Chrysler, Dodge, Jeep, Ram automobile dealership. Current site improvements consist of a single story building with commercial garage, paved parking areas, paved walkways, landscaped areas, and a stormwater management system. Said stormwater management system includes catch basin collection devices and associated subsurface piping. Currently there is no stormwater treatment or recharge/attenuation device on site. As part of the proposed project, the applicant will demolish and remove a portion of the existing building and surrounding paved areas. The applicant will then renovate the remaining portion of the existing building and construct a new drive-through restaurant. Additionally, the project will include the construction of new paved parking areas, sidewalks, accessory site improvements and stormwater management system. The following is an ordered summary of the proposed site improvements: 1. Installation of sediment and erosion control devices. 2. Demolition of a portion of the existing building, surrounding paved areas and stormwater system; 3. Renovation of the remaining building into three retail spaces; 4. Construction of a new Drive-through Restaurant building; 5. Construction of a new stormwater management system in order to provide water quality treatment, groundwater recharge, and peak flow attenuation; 6. Site grading as required; 7. Site paving including drive aisles, parking areas and pedestrian walkways. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 1-2 The proposed project will qualify as a redevelopment project due to the overall reduction of impervious area located on the property. Furthermore, the inclusion of Low-Impact-Development techniques, Environmentally Sensitive Site Design Considerations and stormwater Best Management Practices (BMP) will help mitigate the impacts of the proposed development. BMPs associated with the proposed site design include bio-retention areas, vegetated filter strips, and proprietary sedimentation devices. This report has been prepared to document the compliance of the proposed stormwater management system. The stormwater system has been designed to meet the standards set forth in the City of Northampton Stormwater Management Ordinance as well as the Massachusetts Department of Environmental Protection Stormwater Management Handbook. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 2-1 2. SITE DESCRIPTION 2.1 Predevelopment Conditions The properties to be developed are located at 55 Damon Road in an General Industrial (GI) zone and are listed as parcels 18D-026-001 & 18D-065-001 in the Northampton Assessor’s Office. Figure 1 – USGS Map illustrates the location of the project. The properties are bounded to the north by Damon Road, to the east by Interstate 91, to the south by an Industrial/Office property and to the west by Industrial Drive. The combined parcel area is approximately 1.847 acres in size. The properties have been historically developed and are mostly cleared of natural vegetation. There is an 11,000 square foot building that served as both an automobile sales dealership and automobile repair garage. Adjacent to the existing building is an expansive paved parking area used for vehicle storage. The remaining property area consists of said roof and paved parking areas. The general parcel topography is flat with an approximate elevation of 147 feet along the Damon Road frontage and 148 feet along the Industrial Drive frontage. Interior portions of the site are similar to adjacent roadway grades and range from 146.5 to 148.5. Grassed areas at the northeast portion of the site contain the lowest on site elevation of approximately 145.5 feet. There are three existing catch basins on the property located at a low points within the paved/gravel parking area. Said catch basins will be removed and/or repurposed as part of the proposed site improvements. 2.2 Resource Areas A majority of the parcel where the site improvements are proposed has been historically developed and cleared. There are no bordering or isolated vegetation wetland areas delineated on or adjacent to the parcel. 2.2.1 Floodplain R. Levesque Associates, Inc. performed due diligence research on the property in regards to FEMA flood zone mapping. As demonstrated by the most recent FEMA Flood Insurance Rate Maps, the property is not located within any flood hazard areas, see Figure 2 – FEMA FIRM Map. 2.2.2 Natural Heritage and Endangered Species Program R. Levesque Associates, Inc. performed due diligence research on the property in regards to Natural Heritage and Endangered Species Program (NHESP) areas. The property is not located within any areas delineated by NHESP as estimated or priority habitats of endangered species, see Figure 3 – NHESP Map. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 2-2 2.3 Soils R. Levesque Associates, Inc. researched the soils located on site with information readily available by the United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS). Based on a review of the USDA Soil Survey of Hampden County, Massachusetts, Central Part, the site is comprised of the following soil types: Table 2.4: Hydrologic Soil Group Classification Soil Description Map Unit Symbol Hydrologic Soil Group Amostown-Windsor Silty Substratum – Urban Land Complex 741A B A series of test pits were conducted by Filipe Cravo, P.E. SE# 12839 to evaluate the ability of the site to support the proposed stormwater drainage system components. A total of six test holes were dug in the vicinity of schematic infiltration basin locations. Redoximorphic features observed on site indicate that Estimated Seasonal High Groundwater is located approximately four to five below existing grade, see Appendix B for additional soils information. In general, the soil evaluations corroborated the NRCS mapping of the area. 2.4 Post Development Conditions The applicant is proposing to demolish a portion of the existing building located at 55 Damon Road and renovate the remaining portion into three retail/office spaces. Additionally, the applicant is proposing to construct a 2,500 square foot drive-through restaurant. As part of the project, all of the existing paved areas will be demolished and a new parking and driveway aisle configuration will be constructed. New bicycle parking areas, dumpster enclosures and landscaped areas will be constructed to support the new facilities. In addition to these features, the applicant is proposing the construction of a stormwater management system in order to treat and attenuate stormwater runoff. Said stormwater management system marks a significant improvement over existing conditions (currently stormwater is directed to city infrastructure with no peak flow attenuation or water quality treatment). Water, gas, and sanitary sewer services for the new/renovated buildings will be brought on site via Industrial Drive. Existing utility connections will be reused to the maximum extent practicable. Electric services for the new/renovated buildings will be brought on site via an electric/telecommunications easement on the northeast portion of the site. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 2-3 The proposed stormwater management system consists of two independent treatment trains. Subcatchments proximate to open space areas suitable for rain gardens/bioretention areas utilize curb cut collection at low points, vegetated filter strips and rain gardens/bioretention areas for water quality treatment, infiltration and stormwater attenuation. Subcatchments that are not proximate to open space areas utilize proprietary sedimentation devices for water quality treatment before discharging to city drainage infrastructure. The use of subsurface infiltration basins in these areas was investigated as part of the site design. Said investigation determined that the use of subsurface basins was not readily feasible due to the presence of relatively high groundwater elevations, the height of the subsurface basin profile and the requirement for two feet separation between groundwater and the bottom of the infiltration systems. Due to these site constraints it was determined that shallow surface basins were the only viable option for groundwater infiltration. - The proposed site improvements will maintain the general drainage patterns of the site. All stormwater generated by site improvements will be treated for water quality before discharge to city infrastructure. All stormwater generated by site improvements will be attenuated to the maximum extent practicable prior to discharge. Peak flow rates for the 2, 10 and 100 year storm events have been reduced in order to diminish the burden on city infrastructure. Overall, the proposed site improvements and stormwater management system will be an improvement over existing conditions. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 3-1 3. STORMWATER MANAGEMENT SYSTEM R. Levesque Associates, Inc. has prepared the following drainage system calculations for the proposed project site. These calculations were performed to document compliance with the guidelines set forth by the City of Northampton Stormwater Management Permit requirements and the Massachusetts Department of Environmental Protection Stormwater Management Handbook (MassDEP Handbook). A detailed hydrologic analysis of the system was completed in order to evaluate the performance of the stormwater management system components, see Appendix C – Pre- and Post-Development Hydrologic Analysis. The proposed stormwater management system will collect runoff from on-site impervious areas and utilize stormwater best management practices to provide water quality treatment, groundwater recharge, and peak discharge rate attenuation. 3.1 Drainage Calculations R. Levesque Associates, Inc. utilized the HydroCAD software program, Version 10.0, developed by HydroCAD Software Solutions LLC, in order to create and analyze the site hydrology. The HydroCAD software is based upon the Soil Conservation Service (SCS) “Technical Release 20 – Urban Hydrology for Small Watersheds” and “Technical Release 55 – Urban Hydrology for small Watersheds” which are generally accepted industry standard methodologies. The analysis was conducted in order to establish the peak discharge rates and estimated run-off volume from the project site. This was accomplished to properly evaluate pre- and post-development conditions during various storm events. Contributing drainage areas were identified and soils, surface cover, watershed slope, and flow paths were evaluated to develop the necessary HydroCAD model input parameters. A minimum Time of Concentration (Tc) of (6) minutes was used in the calculations. Drainage calculations were performed for the Pre and Post-Development conditions for the 24- hour, 2, 10, and 100-year Type III storm events. The total rainfall for each of the storm events was based upon data provided by the United States Department of Commerce Technical Paper No. 40 – Rainfall Frequency Atlas of the United States. The total rainfall values used in the hydrologic modeling for each event are shown in the following table: Table 3.1: Design Rainfall Data 2-year, 24-hour storm 10-year, 24-hour storm 100-year, 24-hour storm 3.00 inches 4.50 inches 6.40 inches Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 3-2 3.1.1 Design Points In order to compare the difference between pre and post-development peak flows, existing and proposed watersheds were delineated. Two design points (DP) were established with flow paths representing the longest time of concentration of run-off in each tributary watershed. For this analysis, the design point was determined as follows:  DP-1: City Drainage Infrastructure; this design point represents the runoff from the project area which flows offsite towards the city drainage infrastructure.  DP-2: Easterly Flow; this design point represents the runoff from the project area which flows easterly towards a low area on adjacent land. 3.1.2 Pre-Development Hydrology The project area under existing conditions was analyzed as two subcatchments discharging to the design points as described above. The subcatchments were delineated based on the existing developed areas, detailed site inspection, and existing topography as mapped by an on-the- ground field survey. The existing watershed areas are shown on the attached Figure 4 entitled “Pre-Development Watershed Plan”. Peak discharge rates for the design point are depicted in Table 3.1.4 below. 3.1.3 Post-Development Hydrology The project area under proposed conditions was broken down into seven subcatchments discharging to the same design points as the existing conditions. The proposed watershed areas are shown on the attached Figure 5 entitled “Post-Development Watershed Plan”. Peak discharge rates for the design point are depicted in Table 3.1.4 below. 3.1.4 Peak Discharge Rates The table below summarizes the Pre and Post-Development peak discharge rates for each Design Point: Table 3.1.4 Pre- and Post-Development Peak Discharge Rates 2-year storm (cfs) 10-year storm (cfs) 100-year storm (cfs) Pre- Post- Pre- Post- Pre- Post- Design Point 1 4.44 1.94 6.78 4.57 9.71 7.43 Design Point 2 0.27 0.05 0.60 0.24 1.06 0.56 Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 3-3 As depicted in the table, the post-development peak discharge rates do not increase over pre- development peak discharge rates for each of the storm events presented. This is accomplished by provided onsite attenuation through the proposed bio-retention areas. 3.2 Hydraulic Analysis As part of the stormwater management system design, a hydraulic analysis was performed on the proposed underground infrastructure and is included in the HydroCAD model. The stormwater management system was analyzed to evaluate the performance of the proposed stormwater piping. The proposed stormwater infrastructure has been sized to convey storm events up to and including the 24-hour, 100-year storm event. Please refer to Appendix D for the Hydroflow analysis of the proposed stormwater management system. 3.3 MassDEP Stormwater Management Standards R. Levesque Associates, Inc. has designed the proposed stormwater management system to be in compliance with the MassDEP Stormwater Management Standards. Chapter 1, Volume 3 of the MassDEP Handbook outlines specific calculations, and other information, that must be submitted with each report to document compliance. The following summary highlights elements of the proposed project and how they apply to each standard.  Standard #1 - No new stormwater conveyances (e.g., outfalls) may discharge untreated stormwater directly to or cause erosion in wetlands or waters of the Commonwealth. The proposed project does not introduce any new outfalls and provides best management practices designed to the guidelines of the MassDEP Handbook. Therefore, no new untreated stormwater is discharged.  Standard #2 – Stormwater management systems shall be designed so that post- development peak discharge rates do not exceed pre-development peak discharge rates. This Standard may be waived for discharges to land subject to coastal storm flowage as defined in 310 CMR 10.04. The proposed stormwater management system has been designed such that the post- development peak discharge rates are less than the pre-development discharge rates for the 2-year, 10-year, and 100-year 24-hour storms. See Appendix C for the Hydrologic Analysis.  Standard #3 - Loss of annual recharge to groundwater shall be eliminated or minimized through the use of environmentally sensitive site design, low impact development techniques, stormwater BMPs, and good operation and maintenance. At a minimum, the annual recharge from the post-development site shall approximate the annual recharge Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 3-4 from pre-development conditions based on soil type. This Standard is met when the stormwater management system is designed to infiltrate the required volume as determined in accordance with the Massachusetts Stormwater Handbook. The proposed subsurface infiltration basin has been designed with the capacity to infiltrate the required recharge volume for the tributary impervious areas to the maximum extent practicable. See Appendix E for the Required Recharge Volume Calculations.  Standard #4 – Stormwater management systems shall be designed to remove 80% of the average annual post-construction load of TSS. It is presumed that this standard is met when: a. Suitable practices for source control and pollution prevention are identified in a long term pollution prevention plan, and thereafter are implemented and maintained; b. Structural stormwater BMPs practices are sized to capture the required water quality volume determined in accordance with the Massachusetts Stormwater Handbook; and c. Pretreatment is provided in accordance with the Massachusetts Stormwater Handbook The treatment train for the proposed stormwater management system includes vegetated filter strips, rain garden/bioretention areas, and proprietary sedimentation devices in order to meet the water quality standards. See Appendix E for the Water Quality Volume Calculations.  Standard #5 - For land uses with higher potential pollutant loads, source control and pollution prevention shall be implemented in accordance with the Massachusetts Stormwater Handbook to eliminate or reduce the discharge of stormwater runoff from such land uses to the maximum extent practicable. If through source control and/or pollution prevention all land uses with higher potential pollutant loads cannot be completely protected from exposure to rain, snow, snow melt, and stormwater runoff, the proponent shall use the specific structural stormwater BMPs determined by MassDEP to be suitable for such uses as provided in the Massachusetts Stormwater Handbook. Stormwater discharges from land uses with higher potential pollutant loads shall also comply with the requirements of the Massachusetts Clean Waters Act, M.G.L. c. 21, §§ 26-53 and the regulations promulgated thereunder at 314 CMR 3.00, 314 CMR 4.00 and 314 CMR 5.00. This standard is not applicable.  Standard #6 – Stormwater discharges within the Zone II or Interim Wellhead Protection Area of a public water supply, and stormwater discharges near or to any other critical area, require the use of the specific source control and pollution prevention measures and the specific structural stormwater BMPs determined by MassDEP to be suitable for managing Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 3-5 discharges to such areas, as provided in the Massachusetts Stormwater Handbook. A discharge is near a critical area if there is a strong likelihood of a significant impact occurring to said area, taking into account site-specific factors. Stormwater discharges to Outstanding Resource Waters and Special Resource Waters shall be removed and set back from the receiving water or wetland and receive the highest and best practical method of treatment. A “storm water discharge” as defined in 314 CMR 3.04(2)(a)1 or (b) to an Outstanding Resource Water or Special Resource Water shall comply with 314 CMR 3.00 and 314 CMR 4.00. Stormwater discharges to a Zone I or Zone A are prohibited unless essential to the operation of a public water supply. This standard is not applicable.  Standard #7 – A redevelopment project is required to meet the following Stormwater Management Standards only to the maximum extent practicable: Standard 2, Standard 3, and the pretreatment and structural BMPs requirements of Standards 4, 5, and 6. Existing stormwater discharges shall comply with Standard 1 only to the maximum extent practicable. A redevelopment project shall also comply with all other requirements of the Stormwater Management Standards and improve existing conditions. The project is considered a redevelopment due to the site being historically developed and the proposed site improvements reducing the overall impervious area. Under existing conditions, runoff is captured via three catch basins in the paved/gravel parking area adjacent to the buildings and is conveyed to the city drainage infrastructure in Damon Road. The proposed stormwater management system will reduce flow rates tributary to city drainage infrastructure, provide water quality treatment, groundwater recharge, and peak rate attenuation which currently do not exist. Overall, the proposed stormwater management system will provide a substantial improvement over the existing conditions.  Standard #8 – A plan to control construction-related impacts including erosion, sedimentation and other pollutant sources during construction and land disturbance activities (construction period erosion, sedimentation, and pollution prevention) shall be developed and implemented. A Construction Period Erosion Control Plan has been provided in Appendix F.  Standard #9 – A long-term operation and maintenance plan shall be developed and implemented to ensure that stormwater management systems function as designed. A Long-term Operation & Maintenance Plan has been provided in Appendix G.  Standard #10 - All illicit discharges to the stormwater management system are prohibited. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 3-6 An illicit discharge statement will be provided prior to discharge of stormwater to post- construction BMPs. See Appendix G for a copy of the Illicit Discharge Statement. 3.4 Stormwater Best Management Practices The proposed stormwater management system was designed utilizing stormwater best management practices (BMP) as set forth by the MassDEP Handbook. The BMPs utilized as part of the stormwater management system include proprietary sedimentation devices, underground infrastructure, vegetated filter strips, and rain gardens/bioretention areas. All of the BMPs were designed to meet the requirements of the MassDEP Handbook and will provide water quality treatment, groundwater recharge, and peak rate attenuation in order to mitigate the impacts of the proposed site improvements. See Appendix E – MassDEP Calculations for the calculations required to document compliance. The following section provides a description of the best management practices (BMPs) being utilized on site. 3.4.1 Bio-Retention Areas Bio-retention areas are a best management practice which is being utilized on site as part of the stormwater management system treatment train process to enhance water runoff quality. Bio- retention areas utilize soils, plants, and microbes to treat stormwater before it is discharged to downstream drainage infrastructure or infiltrated to provide groundwater recharge via an underdrain. The proposed bio-retention areas associated with this project will provide aesthetically pleasing vegetation within the paved parking area. Additionally, the bio-retention areas will provide stormwater pre-treatment prior to discharge to the drainage infrastructure. 3.4.2 Proprietary Sedimentation Devices Proprietary sedimentation devices are being utilized on site for the treatment of stormwater runoff. As much sediment should be removed from the stormwater runoff as possible to avoid clogging down-gradient infrastructure. Therefore, maintenance of the proprietary device is crucial to the long-term effectiveness of drainage infrastructure. The stormwater management system is utilizing proprietary treatment devices in order to ensure that the amount of sediment reaching city drainage infrastructure is negligible. 3.5 Protection of Stormwater Best Management Practices during Construction Protection of the stormwater best management practices during construction will ensure the proper functioning of the stormwater management system and provide protection to the undisturbed areas until the site has been stabilized. Certain specific erosion and sedimentation controls and good practices to be performed by the site contractor have been documented in a Construction Period Erosion Control Plan. See Appendix F – Construction Period Erosion Control Plan. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 3-7 3.6 Inspection and Maintenance of Stormwater Best Management Practices Frequent maintenance of the stormwater best management practices is essential to ensuring that the stormwater management system will function properly long-term. The MassDEP provides guidelines for the regular inspection and maintenance of the proposed stormwater best management practices. A Long-Term Stormwater Operation and Maintenance Plan has been prepared which dictates the inspection frequency and maintenance operations for each BMP. See Appendix G – Long-Term Operation and Maintenance Plan. 3.7 Illicit Discharge Compliance Statement RLA has prepared an Illicit Discharge Compliance Statement to document compliance with the Massachusetts Department of Environmental Protection Stormwater Management Handbook, see Appendix H. 3.8 Northampton DPW Inspection Schedule Checklist RLA has prepared a checklist for the proposed project in order to identify specific milestones where the Department of Public Works shall make an inspection, see Appendix I. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 4-1 4. CONCLUSION The proposed stormwater management system has been designed to mitigate the impacts of the proposed site improvements by providing a control for runoff water quality and water quantity. Implementation of Low-Impact-Development stormwater best management practices such as vegetated filter strips, bio-retention areas, and proprietary sedimentation devices allows for a stormwater drainage design that is in conformance with the criteria set forth in the City of Northampton Stormwater Management Ordinance requirements and the Massachusetts Department of Environmental Protection Stormwater Management Handbook. As the project is considered a redevelopment, the proposed stormwater management system is subject to the MassDEP Stormwater Standards only to the “maximum extent practicable” however, every effort has been made such that the proposed stormwater management system is in full compliance when practical. Additionally, the proposed site improvement and stormwater management system provides a marked improvement over existing conditions. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Figure 1: Site Locus – USGS Map R L A SCALE: DATE: JOB NO: ph: 413.568.0985 fax: 413.568.0986 rlaland.com 6FKRRO6WUHHWĈ32%R[Ĉ:HVWILHOG0$ R LEVESQUE ASSOCIATES, INC A Land Planning Services Company 170334 08/10/17 AS NOTED American Dream Realty c/o Mr. Emanuel Sardinha 16 Harvard Street Westfield, MA 01085 Proposed Drive-Thru Restaurant 55 Damon Road Northampton, MA SITE FIG-1 SITE LOCUS USGS MAP Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Figure 2: FEMA Flood Map SITE R L A SCALE: DATE: JOB NO: ph: 413.568.0985 fax: 413.568.0986 rlaland.com 6FKRRO6WUHHWĈ32%R[Ĉ:HVWILHOG0$ R LEVESQUE ASSOCIATES, INC A Land Planning Services Company 170334 08/10/17 AS NOTED American Dream Realty c/o Mr. Emanuel Sardinha 16 Harvard Street Westfield, MA 01085 Proposed Drive-Thru Restaurant 55 Damon Road Northampton, MA FIG-2 FLOOD RATE INSURANCE MAP FEMA FIRM 25013C0190F Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Figure 3: NHESP Map SITE R L A SCALE: DATE: JOB NO: ph: 413.568.0985 fax: 413.568.0986 rlaland.com 6FKRRO6WUHHWĈ32%R[Ĉ:HVWILHOG0$ R LEVESQUE ASSOCIATES, INC A Land Planning Services Company 170334 08/10/17 AS NOTED American Dream Realty c/o Mr. Emanuel Sardinha 16 Harvard Street Westfield, MA 01085 Proposed Drive-Thru Restaurant 55 Damon Road Northampton, MA FIG-3 Natural Heritage and Endangered Species Map Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Figure 4: Pre-Development Watershed Plan SCALE: DATE: JOB NO.:ph: 413.568.0985 fax: 413.568.0986 rlaland.com6FKRRO6WUHHWĈ32%R[Ĉ:HVWILHOG0$R LEVESQUE ASSOCIATES, INCA Land Planning Services CompanyPre-DevelopmentWatershed PlanProposed Commercial Development55 Damon RoadNorthampton, MAAmerican Dream Realty16 Harvard StreetWestfield, Massachusetts170334 8/10/17 As Noted FIG-4 Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Figure 5: Post-Development Watershed Plan SCALE: DATE: JOB NO.:ph: 413.568.0985 fax: 413.568.0986 rlaland.com6FKRRO6WUHHWĈ32%R[Ĉ:HVWILHOG0$R LEVESQUE ASSOCIATES, INCA Land Planning Services CompanyPost-DevelopmentWatershed PlanProposed Commercial Development55 Damon RoadNorthampton, MAAmerican Dream Realty16 Harvard StreetWestfield, Massachusetts170334 8/10/17 As Noted FIG-5 Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Figure 6: Inlet Area Plan SCALE: DATE: JOB NO.:ph: 413.568.0985 fax: 413.568.0986 rlaland.com6FKRRO6WUHHWĈ32%R[Ĉ:HVWILHOG0$R LEVESQUE ASSOCIATES, INCA Land Planning Services CompanyInlet Area PlanProposed Commercial Development55 Damon RoadNorthampton, MAAmerican Dream Realty16 Harvard StreetWestfield, Massachusetts170334 8/10/17 As Noted FIG-6 Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Appendix A: Checklist for Stormwater Report MassDEP Stormwater Checklist • 04/01/08 Stormwater Report Checklist • Page 1 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report A. Introduction Important: When filling out forms on the computer, use only the tab key to move your cursor - do not use the return key. A Stormwater Report must be submitted with the Notice of Intent permit application to document compliance with the Stormwater Management Standards. The following checklist is NOT a substitute for the Stormwater Report (which should provide more substantive and detailed information) but is offered here as a tool to help the applicant organize their Stormwater Management documentation for their Report and for the reviewer to assess this information in a consistent format. As noted in the Checklist, the Stormwater Report must contain the engineering computations and supporting information set forth in Volume 3 of the Massachusetts Stormwater Handbook. The Stormwater Report must be prepared and certified by a Registered Professional Engineer (RPE) licensed in the Commonwealth. The Stormwater Report must include:  The Stormwater Checklist completed and stamped by a Registered Professional Engineer (see page 2) that certifies that the Stormwater Report contains all required submittals.1 This Checklist is to be used as the cover for the completed Stormwater Report.  Applicant/Project Name  Project Address  Name of Firm and Registered Professional Engineer that prepared the Report  Long-Term Pollution Prevention Plan required by Standards 4-6  Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan required by Standard 82  Operation and Maintenance Plan required by Standard 9 In addition to all plans and supporting information, the Stormwater Report must include a brief narrative describing stormwater management practices, including environmentally sensitive site design and LID techniques, along with a diagram depicting runoff through the proposed BMP treatment train. Plans are required to show existing and proposed conditions, identify all wetland resource areas, NRCS soil types, critical areas, Land Uses with Higher Potential Pollutant Loads (LUHPPL), and any areas on the site where infiltration rate is greater than 2.4 inches per hour. The Plans shall identify the drainage areas for both existing and proposed conditions at a scale that enables verification of supporting calculations. As noted in the Checklist, the Stormwater Management Report shall document compliance with each of the Stormwater Management Standards as provided in the Massachusetts Stormwater Handbook. The soils evaluation and calculations shall be done using the methodologies set forth in Volume 3 of the Massachusetts Stormwater Handbook. To ensure that the Stormwater Report is complete, applicants are required to fill in the Stormwater Report Checklist by checking the box to indicate that the specified information has been included in the Stormwater Report. If any of the information specified in the checklist has not been submitted, the applicant must provide an explanation. The completed Stormwater Report Checklist and Certification must be submitted with the Stormwater Report. 1 The Stormwater Report may also include the Illicit Discharge Compliance Statement required by Standard 10. If not included in the Stormwater Report, the Illicit Discharge Compliance Statement must be submitted prior to the discharge of stormwater runoff to the post-construction best management practices. 2 For some complex projects, it may not be possible to include the Construction Period Erosion and Sedimentation Control Plan in the Stormwater Report. In that event, the issuing authority has the discretion to issue an Order of Conditions that approves the project and includes a condition requiring the proponent to submit the Construction Period Erosion and Sedimentation Control Plan before commencing any land disturbance activity on the site. MassDEP Stormwater Checklist • 04/01/08 Stormwater Report Checklist • Page 3 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) LID Measures: Stormwater Standards require LID measures to be considered. Document what environmentally sensitive design and LID Techniques were considered during the planning and design of the project: No disturbance to any Wetland Resource Areas Site Design Practices (e.g. clustered development, reduced frontage setbacks) Reduced Impervious Area (Redevelopment Only) Minimizing disturbance to existing trees and shrubs LID Site Design Credit Requested: Credit 1 Credit 2 Credit 3 Use of “country drainage” versus curb and gutter conveyance and pipe Bioretention Cells (includes Rain Gardens) Constructed Stormwater Wetlands (includes Gravel Wetlands designs) Treebox Filter Water Quality Swale Grass Channel Green Roof Other (describe): Standard 1: No New Untreated Discharges No new untreated discharges Outlets have been designed so there is no erosion or scour to wetlands and waters of the Commonwealth Supporting calculations specified in Volume 3 of the Massachusetts Stormwater Handbook included. MassDEP Stormwater Checklist • 04/01/08 Stormwater Report Checklist • Page 4 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 2: Peak Rate Attenuation Standard 2 waiver requested because the project is located in land subject to coastal storm flowage and stormwater discharge is to a wetland subject to coastal flooding. Evaluation provided to determine whether off-site flooding increases during the 100-year 24-hour storm. Calculations provided to show that post-development peak discharge rates do not exceed pre- development rates for the 2-year and 10-year 24-hour storms. If evaluation shows that off-site flooding increases during the 100-year 24-hour storm, calculations are also provided to show that post-development peak discharge rates do not exceed pre-development rates for the 100-year 24- hour storm. Standard 3: Recharge Soil Analysis provided. Required Recharge Volume calculation provided. Required Recharge volume reduced through use of the LID site Design Credits. Sizing the infiltration, BMPs is based on the following method: Check the method used. Static Simple Dynamic Dynamic Field1 Runoff from all impervious areas at the site discharging to the infiltration BMP. Runoff from all impervious areas at the site is not discharging to the infiltration BMP and calculations are provided showing that the drainage area contributing runoff to the infiltration BMPs is sufficient to generate the required recharge volume. Recharge BMPs have been sized to infiltrate the Required Recharge Volume. Recharge BMPs have been sized to infiltrate the Required Recharge Volume only to the maximum extent practicable for the following reason: Site is comprised solely of C and D soils and/or bedrock at the land surface M.G.L. c. 21E sites pursuant to 310 CMR 40.0000 Solid Waste Landfill pursuant to 310 CMR 19.000 Project is otherwise subject to Stormwater Management Standards only to the maximum extent practicable. Calculations showing that the infiltration BMPs will drain in 72 hours are provided. Property includes a M.G.L. c. 21E site or a solid waste landfill and a mounding analysis is included. 1 80% TSS removal is required prior to discharge to infiltration BMP if Dynamic Field method is used. MassDEP Stormwater Checklist • 04/01/08 Stormwater Report Checklist • Page 5 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 3: Recharge (continued) The infiltration BMP is used to attenuate peak flows during storms greater than or equal to the 10- year 24-hour storm and separation to seasonal high groundwater is less than 4 feet and a mounding analysis is provided. Documentation is provided showing that infiltration BMPs do not adversely impact nearby wetland resource areas. Standard 4: Water Quality The Long-Term Pollution Prevention Plan typically includes the following:  Good housekeeping practices;  Provisions for storing materials and waste products inside or under cover;  Vehicle washing controls;  Requirements for routine inspections and maintenance of stormwater BMPs;  Spill prevention and response plans;  Provisions for maintenance of lawns, gardens, and other landscaped areas;  Requirements for storage and use of fertilizers, herbicides, and pesticides;  Pet waste management provisions;  Provisions for operation and management of septic systems;  Provisions for solid waste management;  Snow disposal and plowing plans relative to Wetland Resource Areas;  Winter Road Salt and/or Sand Use and Storage restrictions;  Street sweeping schedules;  Provisions for prevention of illicit discharges to the stormwater management system;  Documentation that Stormwater BMPs are designed to provide for shutdown and containment in the event of a spill or discharges to or near critical areas or from LUHPPL;  Training for staff or personnel involved with implementing Long-Term Pollution Prevention Plan;  List of Emergency contacts for implementing Long-Term Pollution Prevention Plan. A Long-Term Pollution Prevention Plan is attached to Stormwater Report and is included as an attachment to the Wetlands Notice of Intent. Treatment BMPs subject to the 44% TSS removal pretreatment requirement and the one inch rule for calculating the water quality volume are included, and discharge: is within the Zone II or Interim Wellhead Protection Area is near or to other critical areas is within soils with a rapid infiltration rate (greater than 2.4 inches per hour) involves runoff from land uses with higher potential pollutant loads. The Required Water Quality Volume is reduced through use of the LID site Design Credits. Calculations documenting that the treatment train meets the 80% TSS removal requirement and, if applicable, the 44% TSS removal pretreatment requirement, are provided. MassDEP Stormwater Checklist • 04/01/08 Stormwater Report Checklist • Page 6 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 4: Water Quality (continued) The BMP is sized (and calculations provided) based on: The ½” or 1” Water Quality Volume or The equivalent flow rate associated with the Water Quality Volume and documentation is provided showing that the BMP treats the required water quality volume. The applicant proposes to use proprietary BMPs, and documentation supporting use of proprietary BMP and proposed TSS removal rate is provided. This documentation may be in the form of the propriety BMP checklist found in Volume 2, Chapter 4 of the Massachusetts Stormwater Handbook and submitting copies of the TARP Report, STEP Report, and/or other third party studies verifying performance of the proprietary BMPs. A TMDL exists that indicates a need to reduce pollutants other than TSS and documentation showing that the BMPs selected are consistent with the TMDL is provided. Standard 5: Land Uses With Higher Potential Pollutant Loads (LUHPPLs) The NPDES Multi-Sector General Permit covers the land use and the Stormwater Pollution Prevention Plan (SWPPP) has been included with the Stormwater Report. The NPDES Multi-Sector General Permit covers the land use and the SWPPP will be submitted prior to the discharge of stormwater to the post-construction stormwater BMPs. The NPDES Multi-Sector General Permit does not cover the land use. LUHPPLs are located at the site and industry specific source control and pollution prevention measures have been proposed to reduce or eliminate the exposure of LUHPPLs to rain, snow, snow melt and runoff, and been included in the long term Pollution Prevention Plan. All exposure has been eliminated. All exposure has not been eliminated and all BMPs selected are on MassDEP LUHPPL list. The LUHPPL has the potential to generate runoff with moderate to higher concentrations of oil and grease (e.g. all parking lots with >1000 vehicle trips per day) and the treatment train includes an oil grit separator, a filtering bioretention area, a sand filter or equivalent. Standard 6: Critical Areas The discharge is near or to a critical area and the treatment train includes only BMPs that MassDEP has approved for stormwater discharges to or near that particular class of critical area. Critical areas and BMPs are identified in the Stormwater Report. MassDEP Stormwater Checklist • 04/01/08 Stormwater Report Checklist • Page 7 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 7: Redevelopments and Other Projects Subject to the Standards only to the maximum extent practicable The project is subject to the Stormwater Management Standards only to the maximum Extent Practicable as a: Limited Project Small Residential Projects: 5-9 single family houses or 5-9 units in a multi-family development provided there is no discharge that may potentially affect a critical area. Small Residential Projects: 2-4 single family houses or 2-4 units in a multi-family development with a discharge to a critical area Marina and/or boatyard provided the hull painting, service and maintenance areas are protected from exposure to rain, snow, snow melt and runoff Bike Path and/or Foot Path Redevelopment Project Redevelopment portion of mix of new and redevelopment. Certain standards are not fully met (Standard No. 1, 8, 9, and 10 must always be fully met) and an explanation of why these standards are not met is contained in the Stormwater Report. The project involves redevelopment and a description of all measures that have been taken to improve existing conditions is provided in the Stormwater Report. The redevelopment checklist found in Volume 2 Chapter 3 of the Massachusetts Stormwater Handbook may be used to document that the proposed stormwater management system (a) complies with Standards 2, 3 and the pretreatment and structural BMP requirements of Standards 4-6 to the maximum extent practicable and (b) improves existing conditions. Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan must include the following information:  Narrative;  Construction Period Operation and Maintenance Plan;  Names of Persons or Entity Responsible for Plan Compliance;  Construction Period Pollution Prevention Measures;  Erosion and Sedimentation Control Plan Drawings;  Detail drawings and specifications for erosion control BMPs, including sizing calculations;  Vegetation Planning;  Site Development Plan;  Construction Sequencing Plan;  Sequencing of Erosion and Sedimentation Controls;  Operation and Maintenance of Erosion and Sedimentation Controls;  Inspection Schedule;  Maintenance Schedule;  Inspection and Maintenance Log Form. A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan containing the information set forth above has been included in the Stormwater Report. MassDEP Stormwater Checklist • 04/01/08 Stormwater Report Checklist • Page 8 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control (continued) The project is highly complex and information is included in the Stormwater Report that explains why it is not possible to submit the Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan with the application. A Construction Period Pollution Prevention and Erosion and Sedimentation Control has not been included in the Stormwater Report but will be submitted before land disturbance begins. The project is not covered by a NPDES Construction General Permit. The project is covered by a NPDES Construction General Permit and a copy of the SWPPP is in the Stormwater Report. The project is covered by a NPDES Construction General Permit but no SWPPP been submitted. The SWPPP will be submitted BEFORE land disturbance begins. Standard 9: Operation and Maintenance Plan The Post Construction Operation and Maintenance Plan is included in the Stormwater Report and includes the following information: Name of the stormwater management system owners; Party responsible for operation and maintenance; Schedule for implementation of routine and non-routine maintenance tasks; Plan showing the location of all stormwater BMPs maintenance access areas; Description and delineation of public safety features; Estimated operation and maintenance budget; and Operation and Maintenance Log Form. The responsible party is not the owner of the parcel where the BMP is located and the Stormwater Report includes the following submissions: A copy of the legal instrument (deed, homeowner’s association, utility trust or other legal entity) that establishes the terms of and legal responsibility for the operation and maintenance of the project site stormwater BMPs; A plan and easement deed that allows site access for the legal entity to operate and maintain BMP functions. Standard 10: Prohibition of Illicit Discharges The Long-Term Pollution Prevention Plan includes measures to prevent illicit discharges; An Illicit Discharge Compliance Statement is attached; NO Illicit Discharge Compliance Statement is attached but will be submitted prior to the discharge of any stormwater to post-construction BMPs. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Appendix B: Soils Information United States Department of Agriculture A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Hampshire County, Massachusetts, Central Part Natural Resources Conservation Service March 2, 2016 Preface Soil surveys contain information that affects land use planning in survey areas. They highlight soil limitations that affect various land uses and provide information about the properties of the soils in the survey areas. Soil surveys are designed for many different users, including farmers, ranchers, foresters, agronomists, urban planners, community officials, engineers, developers, builders, and home buyers. Also, conservationists, teachers, students, and specialists in recreation, waste disposal, and pollution control can use the surveys to help them understand, protect, or enhance the environment. Various land use regulations of Federal, State, and local governments may impose special restrictions on land use or land treatment. Soil surveys identify soil properties that are used in making various land use or land treatment decisions. The information is intended to help the land users identify and reduce the effects of soil limitations on various land uses. The landowner or user is responsible for identifying and complying with existing laws and regulations. Although soil survey information can be used for general farm, local, and wider area planning, onsite investigation is needed to supplement this information in some cases. Examples include soil quality assessments (http://www.nrcs.usda.gov/wps/portal/ nrcs/main/soils/health/) and certain conservation and engineering applications. For more detailed information, contact your local USDA Service Center (http:// offices.sc.egov.usda.gov/locator/app?agency=nrcs) or your NRCS State Soil Scientist (http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/contactus/? cid=nrcs142p2_053951). Great differences in soil properties can occur within short distances. Some soils are seasonally wet or subject to flooding. Some are too unstable to be used as a foundation for buildings or roads. Clayey or wet soils are poorly suited to use as septic tank absorption fields. A high water table makes a soil poorly suited to basements or underground installations. The National Cooperative Soil Survey is a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (NRCS) has leadership for the Federal part of the National Cooperative Soil Survey. Information about soils is updated periodically. Updated information is available through the NRCS Web Soil Survey, the site for official soil survey information. The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means 2 for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer. 3 Contents Preface....................................................................................................................2 How Soil Surveys Are Made..................................................................................5 Soil Map..................................................................................................................7 Soil Map................................................................................................................8 Legend..................................................................................................................9 Map Unit Legend................................................................................................10 Map Unit Descriptions........................................................................................10 Hampshire County, Massachusetts, Central Part...........................................12 741A—Amostown-Windsor silty substratum-Urban land complex, 0 to 3 percent slopes.......................................................................................12 References............................................................................................................14 4 How Soil Surveys Are Made Soil surveys are made to provide information about the soils and miscellaneous areas in a specific area. They include a description of the soils and miscellaneous areas and their location on the landscape and tables that show soil properties and limitations affecting various uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; the kinds of crops and native plants; and the kinds of bedrock. They observed and described many soil profiles. A soil profile is the sequence of natural layers, or horizons, in a soil. The profile extends from the surface down into the unconsolidated material in which the soil formed or from the surface down to bedrock. The unconsolidated material is devoid of roots and other living organisms and has not been changed by other biological activity. Currently, soils are mapped according to the boundaries of major land resource areas (MLRAs). MLRAs are geographically associated land resource units that share common characteristics related to physiography, geology, climate, water resources, soils, biological resources, and land uses (USDA, 2006). Soil survey areas typically consist of parts of one or more MLRA. The soils and miscellaneous areas in a survey area occur in an orderly pattern that is related to the geology, landforms, relief, climate, and natural vegetation of the area. Each kind of soil and miscellaneous area is associated with a particular kind of landform or with a segment of the landform. By observing the soils and miscellaneous areas in the survey area and relating their position to specific segments of the landform, a soil scientist develops a concept, or model, of how they were formed. Thus, during mapping, this model enables the soil scientist to predict with a considerable degree of accuracy the kind of soil or miscellaneous area at a specific location on the landscape. Commonly, individual soils on the landscape merge into one another as their characteristics gradually change. To construct an accurate soil map, however, soil scientists must determine the boundaries between the soils. They can observe only a limited number of soil profiles. Nevertheless, these observations, supplemented by an understanding of the soil-vegetation-landscape relationship, are sufficient to verify predictions of the kinds of soil in an area and to determine the boundaries. Soil scientists recorded the characteristics of the soil profiles that they studied. They noted soil color, texture, size and shape of soil aggregates, kind and amount of rock fragments, distribution of plant roots, reaction, and other features that enable them to identify soils. After describing the soils in the survey area and determining their properties, the soil scientists assigned the soils to taxonomic classes (units). Taxonomic classes are concepts. Each taxonomic class has a set of soil characteristics with precisely defined limits. The classes are used as a basis for comparison to classify soils systematically. Soil taxonomy, the system of taxonomic classification used in the United States, is based mainly on the kind and character of soil properties and the arrangement of horizons within the profile. After the soil scientists classified and named the soils in the survey area, they compared the 5 individual soils with similar soils in the same taxonomic class in other areas so that they could confirm data and assemble additional data based on experience and research. The objective of soil mapping is not to delineate pure map unit components; the objective is to separate the landscape into landforms or landform segments that have similar use and management requirements. Each map unit is defined by a unique combination of soil components and/or miscellaneous areas in predictable proportions. Some components may be highly contrasting to the other components of the map unit. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The delineation of such landforms and landform segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, onsite investigation is needed to define and locate the soils and miscellaneous areas. Soil scientists make many field observations in the process of producing a soil map. The frequency of observation is dependent upon several factors, including scale of mapping, intensity of mapping, design of map units, complexity of the landscape, and experience of the soil scientist. Observations are made to test and refine the soil- landscape model and predictions and to verify the classification of the soils at specific locations. Once the soil-landscape model is refined, a significantly smaller number of measurements of individual soil properties are made and recorded. These measurements may include field measurements, such as those for color, depth to bedrock, and texture, and laboratory measurements, such as those for content of sand, silt, clay, salt, and other components. Properties of each soil typically vary from one point to another across the landscape. Observations for map unit components are aggregated to develop ranges of characteristics for the components. The aggregated values are presented. Direct measurements do not exist for every property presented for every map unit component. Values for some properties are estimated from combinations of other properties. While a soil survey is in progress, samples of some of the soils in the area generally are collected for laboratory analyses and for engineering tests. Soil scientists interpret the data from these analyses and tests as well as the field-observed characteristics and the soil properties to determine the expected behavior of the soils under different uses. Interpretations for all of the soils are field tested through observation of the soils in different uses and under different levels of management. Some interpretations are modified to fit local conditions, and some new interpretations are developed to meet local needs. Data are assembled from other sources, such as research information, production records, and field experience of specialists. For example, data on crop yields under defined levels of management are assembled from farm records and from field or plot experiments on the same kinds of soil. Predictions about soil behavior are based not only on soil properties but also on such variables as climate and biological activity. Soil conditions are predictable over long periods of time, but they are not predictable from year to year. For example, soil scientists can predict with a fairly high degree of accuracy that a given soil will have a high water table within certain depths in most years, but they cannot predict that a high water table will always be at a specific level in the soil on a specific date. After soil scientists located and identified the significant natural bodies of soil in the survey area, they drew the boundaries of these bodies on aerial photographs and identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. Custom Soil Resource Report 6 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. 7 8 Custom Soil Resource Report Soil Map 46882604688270468828046882904688300468831046883204688330468834046883504688360468837046882704688280468829046883004688310468832046883304688340468835046883604688370695650 695660 695670 695680 695690 695700 695710 695720 695650 695660 695670 695680 695690 695700 695710 695720 695730 42° 19' 22'' N 72° 37' 32'' W42° 19' 22'' N72° 37' 28'' W42° 19' 19'' N 72° 37' 32'' W42° 19' 19'' N 72° 37' 28'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 25 50 100 150Feet 0 5 10 20 30Meters Map Scale: 1:567 if printed on A portrait (8.5" x 11") sheet. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features 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 1:15,800. 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: http://websoilsurvey.nrcs.usda.gov 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: Hampshire County, Massachusetts, Central Part Survey Area Data: Version 10, Sep 28, 2015 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Mar 28, 2011—Apr 18, 2011 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. Custom Soil Resource Report 9 Map Unit Legend Hampshire County, Massachusetts, Central Part (MA609) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 741A Amostown-Windsor silty substratum-Urban land complex, 0 to 3 percent slopes 0.7 100.0% Totals for Area of Interest 0.7 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. Custom Soil Resource Report 10 An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha-Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha- Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. Custom Soil Resource Report 11 Hampshire County, Massachusetts, Central Part 741A—Amostown-Windsor silty substratum-Urban land complex, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 99z2 Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 120 to 240 days Farmland classification: Not prime farmland Map Unit Composition Amostown and similar soils: 35 percent Windsor, silty substratum, and similar soils: 25 percent Urban land: 25 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Amostown Setting Landform: Deltas, outwash plains, terraces Landform position (two-dimensional): Summit, footslope Landform position (three-dimensional): Tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Friable sandy glaciofluvial deposits over silty glaciolacustrine deposits Typical profile H1 - 0 to 7 inches: fine sandy loam H2 - 7 to 32 inches: fine sandy loam H3 - 32 to 60 inches: stratified very fine sand to silt loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Moderately well drained Runoff class: Low Capacity of the most limiting layer to transmit water (Ksat): Moderately low to moderately high (0.06 to 0.60 in/hr) Depth to water table: About 18 to 36 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: High (about 9.3 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: B Description of Windsor, Silty Substratum Setting Landform: Outwash plains Custom Soil Resource Report 12 Landform position (two-dimensional): Footslope Landform position (three-dimensional): Tread Down-slope shape: Convex Across-slope shape: Convex Parent material: Loose sandy glaciofluvial deposits over silty glaciolacustrine deposits Typical profile H1 - 0 to 8 inches: loamy sand H2 - 8 to 21 inches: loamy sand H3 - 21 to 45 inches: sand H4 - 45 to 60 inches: silt loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Somewhat excessively drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat): Moderately high (0.20 to 0.60 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Low (about 5.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3s Hydrologic Soil Group: A Minor Components Enosburg Percent of map unit: 10 percent Landform: Terraces Maybid Percent of map unit: 5 percent Landform: Depressions Custom Soil Resource Report 13 References American Association of State Highway and Transportation Officials (AASHTO). 2004. Standard specifications for transportation materials and methods of sampling and testing. 24th edition. American Society for Testing and Materials (ASTM). 2005. Standard classification of soils for engineering purposes. ASTM Standard D2487-00. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of wetlands and deep-water habitats of the United States. U.S. Fish and Wildlife Service FWS/OBS-79/31. Federal Register. July 13, 1994. Changes in hydric soils of the United States. Federal Register. September 18, 2002. Hydric soils of the United States. Hurt, G.W., and L.M. Vasilas, editors. Version 6.0, 2006. Field indicators of hydric soils in the United States. National Research Council. 1995. Wetlands: Characteristics and boundaries. Soil Survey Division Staff. 1993. Soil survey manual. Soil Conservation Service. U.S. Department of Agriculture Handbook 18. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/soils/?cid=nrcs142p2_054262 Soil Survey Staff. 1999. Soil taxonomy: A basic system of soil classification for making and interpreting soil surveys. 2nd edition. Natural Resources Conservation Service, U.S. Department of Agriculture Handbook 436. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/national/soils/?cid=nrcs142p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http://www.nrcs.usda.gov/wps/ portal/nrcs/detail/national/soils/?cid=nrcs142p2_053580 Tiner, R.W., Jr. 1985. Wetlands of Delaware. U.S. Fish and Wildlife Service and Delaware Department of Natural Resources and Environmental Control, Wetlands Section. United States Army Corps of Engineers, Environmental Laboratory. 1987. Corps of Engineers wetlands delineation manual. Waterways Experiment Station Technical Report Y-87-1. United States Department of Agriculture, Natural Resources Conservation Service. National forestry manual. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ home/?cid=nrcs142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nrcs.usda.gov/wps/portal/nrcs/ detail/national/landuse/rangepasture/?cid=stelprdb1043084 14 United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nrcs.usda.gov/wps/portal/ nrcs/detail/soils/scientists/?cid=nrcs142p2_054242 United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land resource regions and major land resource areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296. http://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/soils/? cid=nrcs142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:// www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_052290.pdf Custom Soil Resource Report 15 Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Appendix C: Pre- and Post- Development Hydrologic Analysis (2, 10, & 100 Year Storm Events) ES-1 Subcat ES-1 ES-2 Subcat ES-2 DP-1 Damon Road Drainage DP-2 Easterly flow Routing Diagram for 170334 - PRE Prepared by R Levesque Associates Inc., Printed 8/11/2017 HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Subcat Reach Pond Link 55 Damon Road Type III 24-hr 2-Year Rainfall=3.00"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 2HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Time span=0.00-48.00 hrs, dt=0.05 hrs, 961 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=69,330 sf 87.71% Impervious Runoff Depth=2.66"Subcatchment ES-1: Subcat ES-1 Tc=6.0 min CN=97 Runoff=4.44 cfs 15,358 cf Runoff Area=11,130 sf 0.00% Impervious Runoff Depth=0.96"Subcatchment ES-2: Subcat ES-2 Tc=6.0 min CN=75 Runoff=0.27 cfs 891 cf Inflow=4.44 cfs 15,358 cfLink DP-1: Damon Road Drainage Primary=4.44 cfs 15,358 cf Inflow=0.27 cfs 891 cfLink DP-2: Easterly flow Primary=0.27 cfs 891 cf Total Runoff Area = 80,460 sf Runoff Volume = 16,249 cf Average Runoff Depth = 2.42" 24.42% Pervious = 19,650 sf 75.58% Impervious = 60,810 sf 55 Damon Road Type III 24-hr 2-Year Rainfall=3.00"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 3HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment ES-1: Subcat ES-1 Runoff = 4.44 cfs @ 12.09 hrs, Volume= 15,358 cf, Depth= 2.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Rainfall=3.00" Area (sf) CN Description 2,241 61 >75% Grass cover, Good, HSG B 6,279 96 Gravel surface, HSG B 49,818 98 Paved parking, HSG B 10,992 98 Roofs, HSG B 69,330 97 Weighted Average 8,520 12.29% Pervious Area 60,810 87.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment ES-1: Subcat ES-1 Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)4 3 2 1 0 Type III 24-hr 2-Year Rainfall=3.00" Runoff Area=69,330 sf Runoff Volume=15,358 cf Runoff Depth=2.66" Tc=6.0 min CN=97 4.44 cfs 55 Damon Road Type III 24-hr 2-Year Rainfall=3.00"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 4HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment ES-2: Subcat ES-2 Runoff = 0.27 cfs @ 12.10 hrs, Volume=891 cf, Depth= 0.96" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Rainfall=3.00" Area (sf) CN Description 6,521 61 >75% Grass cover, Good, HSG B 4,609 96 Gravel surface, HSG B 0 98 Paved parking, HSG B 11,130 75 Weighted Average 11,130 100.00% Pervious Area 0 0.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment ES-2: Subcat ES-2 Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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 2-Year Rainfall=3.00" Runoff Area=11,130 sf Runoff Volume=891 cf Runoff Depth=0.96" Tc=6.0 min CN=75 0.27 cfs 55 Damon Road Type III 24-hr 2-Year Rainfall=3.00"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 5HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-1: Damon Road Drainage Inflow Area = 69,330 sf, 87.71% Impervious, Inflow Depth = 2.66" for 2-Year event Inflow = 4.44 cfs @ 12.09 hrs, Volume= 15,358 cf Primary = 4.44 cfs @ 12.09 hrs, Volume= 15,358 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-1: Damon Road Drainage Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)4 3 2 1 0 Inflow Area=69,330 sf 4.44 cfs 4.44 cfs 55 Damon Road Type III 24-hr 2-Year Rainfall=3.00"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 6HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-2: Easterly flow Inflow Area = 11,130 sf, 0.00% Impervious, Inflow Depth = 0.96" for 2-Year event Inflow = 0.27 cfs @ 12.10 hrs, Volume=891 cf Primary = 0.27 cfs @ 12.10 hrs, Volume=891 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-2: Easterly flow Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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=11,130 sf 0.27 cfs 0.27 cfs 55 Damon Road Type III 24-hr 10-Year Rainfall=4.50"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 7HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Time span=0.00-48.00 hrs, dt=0.05 hrs, 961 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=69,330 sf 87.71% Impervious Runoff Depth=4.15"Subcatchment ES-1: Subcat ES-1 Tc=6.0 min CN=97 Runoff=6.78 cfs 23,971 cf Runoff Area=11,130 sf 0.00% Impervious Runoff Depth=2.05"Subcatchment ES-2: Subcat ES-2 Tc=6.0 min CN=75 Runoff=0.60 cfs 1,902 cf Inflow=6.78 cfs 23,971 cfLink DP-1: Damon Road Drainage Primary=6.78 cfs 23,971 cf Inflow=0.60 cfs 1,902 cfLink DP-2: Easterly flow Primary=0.60 cfs 1,902 cf Total Runoff Area = 80,460 sf Runoff Volume = 25,873 cf Average Runoff Depth = 3.86" 24.42% Pervious = 19,650 sf 75.58% Impervious = 60,810 sf 55 Damon Road Type III 24-hr 10-Year Rainfall=4.50"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 8HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment ES-1: Subcat ES-1 Runoff = 6.78 cfs @ 12.09 hrs, Volume= 23,971 cf, Depth= 4.15" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Rainfall=4.50" Area (sf) CN Description 2,241 61 >75% Grass cover, Good, HSG B 6,279 96 Gravel surface, HSG B 49,818 98 Paved parking, HSG B 10,992 98 Roofs, HSG B 69,330 97 Weighted Average 8,520 12.29% Pervious Area 60,810 87.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment ES-1: Subcat ES-1 Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)7 6 5 4 3 2 1 0 Type III 24-hr 10-Year Rainfall=4.50" Runoff Area=69,330 sf Runoff Volume=23,971 cf Runoff Depth=4.15" Tc=6.0 min CN=97 6.78 cfs 55 Damon Road Type III 24-hr 10-Year Rainfall=4.50"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 9HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment ES-2: Subcat ES-2 Runoff = 0.60 cfs @ 12.10 hrs, Volume= 1,902 cf, Depth= 2.05" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Rainfall=4.50" Area (sf) CN Description 6,521 61 >75% Grass cover, Good, HSG B 4,609 96 Gravel surface, HSG B 0 98 Paved parking, HSG B 11,130 75 Weighted Average 11,130 100.00% Pervious Area 0 0.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment ES-2: Subcat ES-2 Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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 10-Year Rainfall=4.50" Runoff Area=11,130 sf Runoff Volume=1,902 cf Runoff Depth=2.05" Tc=6.0 min CN=75 0.60 cfs 55 Damon Road Type III 24-hr 10-Year Rainfall=4.50"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 10HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-1: Damon Road Drainage Inflow Area = 69,330 sf, 87.71% Impervious, Inflow Depth = 4.15" for 10-Year event Inflow = 6.78 cfs @ 12.09 hrs, Volume= 23,971 cf Primary = 6.78 cfs @ 12.09 hrs, Volume= 23,971 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-1: Damon Road Drainage Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)7 6 5 4 3 2 1 0 Inflow Area=69,330 sf 6.78 cfs 6.78 cfs 55 Damon Road Type III 24-hr 10-Year Rainfall=4.50"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 11HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-2: Easterly flow Inflow Area = 11,130 sf, 0.00% Impervious, Inflow Depth = 2.05" for 10-Year event Inflow = 0.60 cfs @ 12.10 hrs, Volume= 1,902 cf Primary = 0.60 cfs @ 12.10 hrs, Volume= 1,902 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-2: Easterly flow Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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=11,130 sf 0.60 cfs 0.60 cfs 55 Damon Road Type III 24-hr 100-Year Rainfall=6.40"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 12HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Time span=0.00-48.00 hrs, dt=0.05 hrs, 961 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=69,330 sf 87.71% Impervious Runoff Depth=6.04"Subcatchment ES-1: Subcat ES-1 Tc=6.0 min CN=97 Runoff=9.71 cfs 34,915 cf Runoff Area=11,130 sf 0.00% Impervious Runoff Depth=3.63"Subcatchment ES-2: Subcat ES-2 Tc=6.0 min CN=75 Runoff=1.06 cfs 3,363 cf Inflow=9.71 cfs 34,915 cfLink DP-1: Damon Road Drainage Primary=9.71 cfs 34,915 cf Inflow=1.06 cfs 3,363 cfLink DP-2: Easterly flow Primary=1.06 cfs 3,363 cf Total Runoff Area = 80,460 sf Runoff Volume = 38,277 cf Average Runoff Depth = 5.71" 24.42% Pervious = 19,650 sf 75.58% Impervious = 60,810 sf 55 Damon Road Type III 24-hr 100-Year Rainfall=6.40"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 13HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment ES-1: Subcat ES-1 Runoff = 9.71 cfs @ 12.09 hrs, Volume= 34,915 cf, Depth= 6.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Rainfall=6.40" Area (sf) CN Description 2,241 61 >75% Grass cover, Good, HSG B 6,279 96 Gravel surface, HSG B 49,818 98 Paved parking, HSG B 10,992 98 Roofs, HSG B 69,330 97 Weighted Average 8,520 12.29% Pervious Area 60,810 87.71% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment ES-1: Subcat ES-1 Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 100-Year Rainfall=6.40" Runoff Area=69,330 sf Runoff Volume=34,915 cf Runoff Depth=6.04" Tc=6.0 min CN=97 9.71 cfs 55 Damon Road Type III 24-hr 100-Year Rainfall=6.40"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 14HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment ES-2: Subcat ES-2 Runoff = 1.06 cfs @ 12.09 hrs, Volume= 3,363 cf, Depth= 3.63" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Rainfall=6.40" Area (sf) CN Description 6,521 61 >75% Grass cover, Good, HSG B 4,609 96 Gravel surface, HSG B 0 98 Paved parking, HSG B 11,130 75 Weighted Average 11,130 100.00% Pervious Area 0 0.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment ES-2: Subcat ES-2 Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 100-Year Rainfall=6.40" Runoff Area=11,130 sf Runoff Volume=3,363 cf Runoff Depth=3.63" Tc=6.0 min CN=75 1.06 cfs 55 Damon Road Type III 24-hr 100-Year Rainfall=6.40"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 15HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-1: Damon Road Drainage Inflow Area = 69,330 sf, 87.71% Impervious, Inflow Depth = 6.04" for 100-Year event Inflow = 9.71 cfs @ 12.09 hrs, Volume= 34,915 cf Primary = 9.71 cfs @ 12.09 hrs, Volume= 34,915 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-1: Damon Road Drainage Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)10 9 8 7 6 5 4 3 2 1 0 Inflow Area=69,330 sf 9.71 cfs 9.71 cfs 55 Damon Road Type III 24-hr 100-Year Rainfall=6.40"170334 - PRE Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 16HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-2: Easterly flow Inflow Area = 11,130 sf, 0.00% Impervious, Inflow Depth = 3.63" for 100-Year event Inflow = 1.06 cfs @ 12.09 hrs, Volume= 3,363 cf Primary = 1.06 cfs @ 12.09 hrs, Volume= 3,363 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-2: Easterly flow Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)1 0 Inflow Area=11,130 sf 1.06 cfs 1.06 cfs PS-1A Subcat PS-1A PS-1B Subcat PS-1B PS-1C Subcat PS-1C PS-1D Subcat PS-1D PS-1E Subcat PS-1E PS-1F Subcat PS-1F PS-2 Subcat ES-2 1P Bio Retention #1 2P Bio Retention #2 DP-1 Damon Road Drainage DP-2 Easterly flow Routing Diagram for 170334 - POST Prepared by R Levesque Associates Inc., Printed 8/11/2017 HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Subcat Reach Pond Link 170334 - POST 170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 2HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (sq-ft) CN Description (subcatchment-numbers) 29,540 61 >75% Grass cover, Good, HSG B (PS-1A, PS-1B, PS-1C, PS-1D, PS-1E, PS-2) 42,475 98 Paved parking, HSG B (PS-1A, PS-1B, PS-1C, PS-1D, PS-1E, PS-2) 8,430 98 Roofs, HSG B (PS-1B, PS-1E, PS-1F) 80,445 84 TOTAL AREA 170334 - POST 170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 3HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (sq-ft) Soil Group Subcatchment Numbers 0 HSG A 80,445 HSG B PS-1A, PS-1B, PS-1C, PS-1D, PS-1E, PS-1F, PS-2 0 HSG C 0 HSG D 0 Other 80,445 TOTAL AREA 170334 - POST 170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 4HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (sq-ft) HSG-B (sq-ft) HSG-C (sq-ft) HSG-D (sq-ft) Other (sq-ft) Total (sq-ft) Ground Cover Subcatchment Numbers 0 29,540 0 0 0 29,540 >75% Grass cover, Good 0 42,475 0 0 0 42,475 Paved parking 0 8,430 0 0 0 8,430 Roofs 0 80,445 0 0 0 80,445 TOTAL AREA 170334 - POST 170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 5HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Pipe Listing (all nodes) Line# Node Number In-Invert (feet) Out-Invert (feet) Length (feet) Slope (ft/ft) n Diam/Width (inches) Height (inches) Inside-Fill (inches) 1 1P 144.51 144.20 62.0 0.0050 0.013 12.0 0.0 0.0 2 2P 144.65 144.20 89.0 0.0051 0.013 12.0 0.0 0.0 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 6HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Time span=0.00-48.00 hrs, dt=0.05 hrs, 961 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=10,441 sf 70.14% Impervious Runoff Depth=1.74"Subcatchment PS-1A: Subcat PS-1A Tc=6.0 min CN=87 Runoff=0.48 cfs 1,513 cf Runoff Area=12,952 sf 71.41% Impervious Runoff Depth=1.74"Subcatchment PS-1B: Subcat PS-1B Tc=6.0 min CN=87 Runoff=0.59 cfs 1,877 cf Runoff Area=26,820 sf 75.66% Impervious Runoff Depth=1.90"Subcatchment PS-1C: Subcat PS-1C Tc=6.0 min CN=89 Runoff=1.34 cfs 4,246 cf Runoff Area=11,894 sf 45.07% Impervious Runoff Depth=1.13"Subcatchment PS-1D: Subcat PS-1D Tc=6.0 min CN=78 Runoff=0.35 cfs 1,119 cf Runoff Area=6,582 sf 98.75% Impervious Runoff Depth=2.77"Subcatchment PS-1E: Subcat PS-1E Tc=6.0 min CN=98 Runoff=0.43 cfs 1,518 cf Runoff Area=0.050 ac 100.00% Impervious Runoff Depth=2.77"Subcatchment PS-1F: Subcat PS-1F Tc=6.0 min CN=98 Runoff=0.14 cfs 502 cf Runoff Area=9,579 sf 0.02% Impervious Runoff Depth=0.37"Subcatchment PS-2: Subcat ES-2 Tc=6.0 min CN=61 Runoff=0.05 cfs 291 cf Peak Elev=147.11' Storage=1,120 cf Inflow=1.34 cfs 4,246 cfPond 1P: Bio Retention #1 Discarded=0.06 cfs 2,744 cf Primary=0.65 cfs 1,501 cf Outflow=0.72 cfs 4,245 cf Peak Elev=147.15' Storage=410 cf Inflow=0.35 cfs 1,119 cfPond 2P: Bio Retention #2 Discarded=0.02 cfs 978 cf Primary=0.06 cfs 141 cf Outflow=0.08 cfs 1,119 cf Inflow=1.94 cfs 7,053 cfLink DP-1: Damon Road Drainage Primary=1.94 cfs 7,053 cf Inflow=0.05 cfs 291 cfLink DP-2: Easterly flow Primary=0.05 cfs 291 cf Total Runoff Area = 80,445 sf Runoff Volume = 11,067 cf Average Runoff Depth = 1.65" 36.72% Pervious = 29,540 sf 63.28% Impervious = 50,905 sf 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 7HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1A: Subcat PS-1A Runoff = 0.48 cfs @ 12.09 hrs, Volume= 1,513 cf, Depth= 1.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Rainfall=3.00" Area (sf) CN Description 3,117 61 >75% Grass cover, Good, HSG B 7,324 98 Paved parking, HSG B 10,441 87 Weighted Average 3,117 29.86% Pervious Area 7,324 70.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1A: Subcat PS-1A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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 2-Year Rainfall=3.00" Runoff Area=10,441 sf Runoff Volume=1,513 cf Runoff Depth=1.74" Tc=6.0 min CN=87 0.48 cfs 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 8HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1B: Subcat PS-1B Runoff = 0.59 cfs @ 12.09 hrs, Volume= 1,877 cf, Depth= 1.74" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Rainfall=3.00" Area (sf) CN Description 3,703 61 >75% Grass cover, Good, HSG B 9,249 98 Paved parking, HSG B 0 98 Roofs, HSG B 12,952 87 Weighted Average 3,703 28.59% Pervious Area 9,249 71.41% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1B: Subcat PS-1B Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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 2-Year Rainfall=3.00" Runoff Area=12,952 sf Runoff Volume=1,877 cf Runoff Depth=1.74" Tc=6.0 min CN=87 0.59 cfs 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 9HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1C: Subcat PS-1C Runoff = 1.34 cfs @ 12.09 hrs, Volume= 4,246 cf, Depth= 1.90" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Rainfall=3.00" Area (sf) CN Description 6,527 61 >75% Grass cover, Good, HSG B 20,293 98 Paved parking, HSG B 26,820 89 Weighted Average 6,527 24.34% Pervious Area 20,293 75.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1C: Subcat PS-1C Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 2-Year Rainfall=3.00" Runoff Area=26,820 sf Runoff Volume=4,246 cf Runoff Depth=1.90" Tc=6.0 min CN=89 1.34 cfs 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 10HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1D: Subcat PS-1D Runoff = 0.35 cfs @ 12.10 hrs, Volume= 1,119 cf, Depth= 1.13" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Rainfall=3.00" Area (sf) CN Description 6,533 61 >75% Grass cover, Good, HSG B 5,361 98 Paved parking, HSG B 11,894 78 Weighted Average 6,533 54.93% Pervious Area 5,361 45.07% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1D: Subcat PS-1D Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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=3.00" Runoff Area=11,894 sf Runoff Volume=1,119 cf Runoff Depth=1.13" Tc=6.0 min CN=78 0.35 cfs 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 11HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1E: Subcat PS-1E Runoff = 0.43 cfs @ 12.09 hrs, Volume= 1,518 cf, Depth= 2.77" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Rainfall=3.00" Area (sf) CN Description 82 61 >75% Grass cover, Good, HSG B 247 98 Paved parking, HSG B 6,252 98 Roofs, HSG B 6,582 98 Weighted Average 82 1.25% Pervious Area 6,500 98.75% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1E: Subcat PS-1E Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)0.48 0.46 0.44 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 2-Year Rainfall=3.00" Runoff Area=6,582 sf Runoff Volume=1,518 cf Runoff Depth=2.77" Tc=6.0 min CN=98 0.43 cfs 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 12HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1F: Subcat PS-1F Runoff = 0.14 cfs @ 12.09 hrs, Volume=502 cf, Depth= 2.77" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Rainfall=3.00" Area (ac) CN Description 0.050 98 Roofs, HSG B 0.050 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1F: Subcat PS-1F Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)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=3.00" Runoff Area=0.050 ac Runoff Volume=502 cf Runoff Depth=2.77" Tc=6.0 min CN=98 0.14 cfs 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 13HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-2: Subcat ES-2 Runoff = 0.05 cfs @ 12.15 hrs, Volume=291 cf, Depth= 0.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Rainfall=3.00" Area (sf) CN Description 9,578 61 >75% Grass cover, Good, HSG B 1 98 Paved parking, HSG B 9,579 61 Weighted Average 9,578 99.98% Pervious Area 1 0.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-2: Subcat ES-2 Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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 2-Year Rainfall=3.00" Runoff Area=9,579 sf Runoff Volume=291 cf Runoff Depth=0.37" Tc=6.0 min CN=61 0.05 cfs 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 14HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Pond 1P: Bio Retention #1 Inflow Area = 26,820 sf, 75.66% Impervious, Inflow Depth = 1.90" for 2-Year event Inflow = 1.34 cfs @ 12.09 hrs, Volume= 4,246 cf Outflow = 0.72 cfs @ 12.24 hrs, Volume= 4,245 cf, Atten= 46%, Lag= 8.6 min Discarded = 0.06 cfs @ 12.23 hrs, Volume= 2,744 cf Primary = 0.65 cfs @ 12.24 hrs, Volume= 1,501 cf Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 147.11' @ 12.23 hrs Surf.Area= 2,660 sf Storage= 1,120 cf Plug-Flow detention time= 82.6 min calculated for 4,240 cf (100% of inflow) Center-of-Mass det. time= 82.3 min ( 896.0 - 813.7 ) Volume Invert Avail.Storage Storage Description #1 146.65' 2,028 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (feet) (cubic-feet) (cubic-feet)(sq-ft) 146.65 2,222 194.1 0 0 2,222 147.15 2,701 209.8 1,229 1,229 2,737 147.40 3,719 238.0 799 2,028 3,743 Device Routing Invert Outlet Devices #1 Primary 144.51'12.0" Round Culvert L= 62.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 144.51' / 144.20' S= 0.0050 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 146.95'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Discarded 146.65'1.020 in/hr Exfiltration over Wetted area Discarded OutFlow Max=0.06 cfs @ 12.23 hrs HW=147.11' (Free Discharge) 3=Exfiltration (Exfiltration Controls 0.06 cfs) Primary OutFlow Max=0.65 cfs @ 12.24 hrs HW=147.11' (Free Discharge) 1=Culvert (Passes 0.65 cfs of 4.33 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.65 cfs @ 1.30 fps) 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 15HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Pond 1P: Bio Retention #1 Inflow Outflow Discarded Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)1 0 Inflow Area=26,820 sf Peak Elev=147.11' Storage=1,120 cf 1.34 cfs 0.72 cfs 0.06 cfs 0.65 cfs 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 16HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Pond 2P: Bio Retention #2 Inflow Area = 11,894 sf, 45.07% Impervious, Inflow Depth = 1.13" for 2-Year event Inflow = 0.35 cfs @ 12.10 hrs, Volume= 1,119 cf Outflow = 0.08 cfs @ 12.54 hrs, Volume= 1,119 cf, Atten= 76%, Lag= 26.3 min Discarded = 0.02 cfs @ 12.54 hrs, Volume=978 cf Primary = 0.06 cfs @ 12.54 hrs, Volume=141 cf Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 147.15' @ 12.54 hrs Surf.Area= 1,005 sf Storage= 410 cf Plug-Flow detention time= 175.0 min calculated for 1,118 cf (100% of inflow) Center-of-Mass det. time= 174.9 min ( 1,027.6 - 852.8 ) Volume Invert Avail.Storage Storage Description #1 146.62'693 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (feet) (cubic-feet) (cubic-feet)(sq-ft) 146.62 601 123.0 0 0 601 147.12 928 139.0 379 379 941 147.37 1,614 167.0 314 693 1,624 Device Routing Invert Outlet Devices #1 Primary 144.65'12.0" Round Culvert L= 89.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 144.65' / 144.20' S= 0.0051 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 147.12'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Discarded 146.62'1.020 in/hr Exfiltration over Wetted area Discarded OutFlow Max=0.02 cfs @ 12.54 hrs HW=147.15' (Free Discharge) 3=Exfiltration (Exfiltration Controls 0.02 cfs) Primary OutFlow Max=0.06 cfs @ 12.54 hrs HW=147.15' (Free Discharge) 1=Culvert (Passes 0.06 cfs of 4.06 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.06 cfs @ 0.58 fps) 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 17HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Pond 2P: Bio Retention #2 Inflow Outflow Discarded Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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=11,894 sf Peak Elev=147.15' Storage=410 cf 0.35 cfs 0.08 cfs 0.02 cfs 0.06 cfs 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 18HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-1: Damon Road Drainage Inflow Area = 70,866 sf, 71.83% Impervious, Inflow Depth = 1.19" for 2-Year event Inflow = 1.94 cfs @ 12.12 hrs, Volume= 7,053 cf Primary = 1.94 cfs @ 12.12 hrs, Volume= 7,053 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-1: Damon Road Drainage Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)2 1 0 Inflow Area=70,866 sf 1.94 cfs 1.94 cfs 170334 - POST Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 19HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-2: Easterly flow Inflow Area = 9,579 sf, 0.02% Impervious, Inflow Depth = 0.37" for 2-Year event Inflow = 0.05 cfs @ 12.15 hrs, Volume=291 cf Primary = 0.05 cfs @ 12.15 hrs, Volume=291 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-2: Easterly flow Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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=9,579 sf 0.05 cfs 0.05 cfs 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 20HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Time span=0.00-48.00 hrs, dt=0.05 hrs, 961 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=10,441 sf 70.14% Impervious Runoff Depth=3.10"Subcatchment PS-1A: Subcat PS-1A Tc=6.0 min CN=87 Runoff=0.84 cfs 2,696 cf Runoff Area=12,952 sf 71.41% Impervious Runoff Depth=3.10"Subcatchment PS-1B: Subcat PS-1B Tc=6.0 min CN=87 Runoff=1.04 cfs 3,345 cf Runoff Area=26,820 sf 75.66% Impervious Runoff Depth=3.30"Subcatchment PS-1C: Subcat PS-1C Tc=6.0 min CN=89 Runoff=2.27 cfs 7,365 cf Runoff Area=11,894 sf 45.07% Impervious Runoff Depth=2.29"Subcatchment PS-1D: Subcat PS-1D Tc=6.0 min CN=78 Runoff=0.72 cfs 2,272 cf Runoff Area=6,582 sf 98.75% Impervious Runoff Depth=4.26"Subcatchment PS-1E: Subcat PS-1E Tc=6.0 min CN=98 Runoff=0.65 cfs 2,339 cf Runoff Area=0.050 ac 100.00% Impervious Runoff Depth=4.26"Subcatchment PS-1F: Subcat PS-1F Tc=6.0 min CN=98 Runoff=0.21 cfs 774 cf Runoff Area=9,579 sf 0.02% Impervious Runoff Depth=1.08"Subcatchment PS-2: Subcat ES-2 Tc=6.0 min CN=61 Runoff=0.24 cfs 862 cf Peak Elev=147.25' Storage=1,506 cf Inflow=2.27 cfs 7,365 cfPond 1P: Bio Retention #1 Discarded=0.07 cfs 3,480 cf Primary=1.66 cfs 3,885 cf Outflow=1.73 cfs 7,365 cf Peak Elev=147.26' Storage=528 cf Inflow=0.72 cfs 2,272 cfPond 2P: Bio Retention #2 Discarded=0.03 cfs 1,268 cf Primary=0.51 cfs 1,005 cf Outflow=0.54 cfs 2,272 cf Inflow=4.57 cfs 14,044 cfLink DP-1: Damon Road Drainage Primary=4.57 cfs 14,044 cf Inflow=0.24 cfs 862 cfLink DP-2: Easterly flow Primary=0.24 cfs 862 cf Total Runoff Area = 80,445 sf Runoff Volume = 19,652 cf Average Runoff Depth = 2.93" 36.72% Pervious = 29,540 sf 63.28% Impervious = 50,905 sf 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 21HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1A: Subcat PS-1A Runoff = 0.84 cfs @ 12.09 hrs, Volume= 2,696 cf, Depth= 3.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Rainfall=4.50" Area (sf) CN Description 3,117 61 >75% Grass cover, Good, HSG B 7,324 98 Paved parking, HSG B 10,441 87 Weighted Average 3,117 29.86% Pervious Area 7,324 70.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1A: Subcat PS-1A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)0.9 0.85 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 10-Year Rainfall=4.50" Runoff Area=10,441 sf Runoff Volume=2,696 cf Runoff Depth=3.10" Tc=6.0 min CN=87 0.84 cfs 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 22HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1B: Subcat PS-1B Runoff = 1.04 cfs @ 12.09 hrs, Volume= 3,345 cf, Depth= 3.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Rainfall=4.50" Area (sf) CN Description 3,703 61 >75% Grass cover, Good, HSG B 9,249 98 Paved parking, HSG B 0 98 Roofs, HSG B 12,952 87 Weighted Average 3,703 28.59% Pervious Area 9,249 71.41% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1B: Subcat PS-1B Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 10-Year Rainfall=4.50" Runoff Area=12,952 sf Runoff Volume=3,345 cf Runoff Depth=3.10" Tc=6.0 min CN=87 1.04 cfs 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 23HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1C: Subcat PS-1C Runoff = 2.27 cfs @ 12.09 hrs, Volume= 7,365 cf, Depth= 3.30" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Rainfall=4.50" Area (sf) CN Description 6,527 61 >75% Grass cover, Good, HSG B 20,293 98 Paved parking, HSG B 26,820 89 Weighted Average 6,527 24.34% Pervious Area 20,293 75.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1C: Subcat PS-1C Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)2 1 0 Type III 24-hr 10-Year Rainfall=4.50" Runoff Area=26,820 sf Runoff Volume=7,365 cf Runoff Depth=3.30" Tc=6.0 min CN=89 2.27 cfs 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 24HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1D: Subcat PS-1D Runoff = 0.72 cfs @ 12.09 hrs, Volume= 2,272 cf, Depth= 2.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Rainfall=4.50" Area (sf) CN Description 6,533 61 >75% Grass cover, Good, HSG B 5,361 98 Paved parking, HSG B 11,894 78 Weighted Average 6,533 54.93% Pervious Area 5,361 45.07% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1D: Subcat PS-1D Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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 10-Year Rainfall=4.50" Runoff Area=11,894 sf Runoff Volume=2,272 cf Runoff Depth=2.29" Tc=6.0 min CN=78 0.72 cfs 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 25HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1E: Subcat PS-1E Runoff = 0.65 cfs @ 12.09 hrs, Volume= 2,339 cf, Depth= 4.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Rainfall=4.50" Area (sf) CN Description 82 61 >75% Grass cover, Good, HSG B 247 98 Paved parking, HSG B 6,252 98 Roofs, HSG B 6,582 98 Weighted Average 82 1.25% Pervious Area 6,500 98.75% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1E: Subcat PS-1E Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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 10-Year Rainfall=4.50" Runoff Area=6,582 sf Runoff Volume=2,339 cf Runoff Depth=4.26" Tc=6.0 min CN=98 0.65 cfs 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 26HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1F: Subcat PS-1F Runoff = 0.21 cfs @ 12.09 hrs, Volume=774 cf, Depth= 4.26" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Rainfall=4.50" Area (ac) CN Description 0.050 98 Roofs, HSG B 0.050 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1F: Subcat PS-1F Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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 10-Year Rainfall=4.50" Runoff Area=0.050 ac Runoff Volume=774 cf Runoff Depth=4.26" Tc=6.0 min CN=98 0.21 cfs 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 27HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-2: Subcat ES-2 Runoff = 0.24 cfs @ 12.11 hrs, Volume=862 cf, Depth= 1.08" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Rainfall=4.50" Area (sf) CN Description 9,578 61 >75% Grass cover, Good, HSG B 1 98 Paved parking, HSG B 9,579 61 Weighted Average 9,578 99.98% Pervious Area 1 0.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-2: Subcat ES-2 Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)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=4.50" Runoff Area=9,579 sf Runoff Volume=862 cf Runoff Depth=1.08" Tc=6.0 min CN=61 0.24 cfs 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 28HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Pond 1P: Bio Retention #1 Inflow Area = 26,820 sf, 75.66% Impervious, Inflow Depth = 3.30" for 10-Year event Inflow = 2.27 cfs @ 12.09 hrs, Volume= 7,365 cf Outflow = 1.73 cfs @ 12.16 hrs, Volume= 7,365 cf, Atten= 24%, Lag= 4.4 min Discarded = 0.07 cfs @ 12.16 hrs, Volume= 3,480 cf Primary = 1.66 cfs @ 12.16 hrs, Volume= 3,885 cf Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 147.25' @ 12.16 hrs Surf.Area= 3,073 sf Storage= 1,506 cf Plug-Flow detention time= 67.7 min calculated for 7,357 cf (100% of inflow) Center-of-Mass det. time= 67.7 min ( 865.9 - 798.1 ) Volume Invert Avail.Storage Storage Description #1 146.65' 2,028 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (feet) (cubic-feet) (cubic-feet)(sq-ft) 146.65 2,222 194.1 0 0 2,222 147.15 2,701 209.8 1,229 1,229 2,737 147.40 3,719 238.0 799 2,028 3,743 Device Routing Invert Outlet Devices #1 Primary 144.51'12.0" Round Culvert L= 62.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 144.51' / 144.20' S= 0.0050 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 146.95'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Discarded 146.65'1.020 in/hr Exfiltration over Wetted area Discarded OutFlow Max=0.07 cfs @ 12.16 hrs HW=147.24' (Free Discharge) 3=Exfiltration (Exfiltration Controls 0.07 cfs) Primary OutFlow Max=1.63 cfs @ 12.16 hrs HW=147.24' (Free Discharge) 1=Culvert (Passes 1.63 cfs of 4.46 cfs potential flow) 2=Orifice/Grate (Weir Controls 1.63 cfs @ 1.77 fps) 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 29HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Pond 1P: Bio Retention #1 Inflow Outflow Discarded Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)2 1 0 Inflow Area=26,820 sf Peak Elev=147.25' Storage=1,506 cf 2.27 cfs 1.73 cfs 0.07 cfs 1.66 cfs 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 30HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Pond 2P: Bio Retention #2 Inflow Area = 11,894 sf, 45.07% Impervious, Inflow Depth = 2.29" for 10-Year event Inflow = 0.72 cfs @ 12.09 hrs, Volume= 2,272 cf Outflow = 0.54 cfs @ 12.17 hrs, Volume= 2,272 cf, Atten= 25%, Lag= 4.8 min Discarded = 0.03 cfs @ 12.17 hrs, Volume= 1,268 cf Primary = 0.51 cfs @ 12.17 hrs, Volume= 1,005 cf Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 147.26' @ 12.17 hrs Surf.Area= 1,276 sf Storage= 528 cf Plug-Flow detention time= 119.2 min calculated for 2,272 cf (100% of inflow) Center-of-Mass det. time= 119.1 min ( 951.1 - 831.9 ) Volume Invert Avail.Storage Storage Description #1 146.62'693 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (feet) (cubic-feet) (cubic-feet)(sq-ft) 146.62 601 123.0 0 0 601 147.12 928 139.0 379 379 941 147.37 1,614 167.0 314 693 1,624 Device Routing Invert Outlet Devices #1 Primary 144.65'12.0" Round Culvert L= 89.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 144.65' / 144.20' S= 0.0051 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 147.12'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Discarded 146.62'1.020 in/hr Exfiltration over Wetted area Discarded OutFlow Max=0.03 cfs @ 12.17 hrs HW=147.25' (Free Discharge) 3=Exfiltration (Exfiltration Controls 0.03 cfs) Primary OutFlow Max=0.49 cfs @ 12.17 hrs HW=147.25' (Free Discharge) 1=Culvert (Passes 0.49 cfs of 4.17 cfs potential flow) 2=Orifice/Grate (Weir Controls 0.49 cfs @ 1.18 fps) 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 31HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Pond 2P: Bio Retention #2 Inflow Outflow Discarded Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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=11,894 sf Peak Elev=147.26' Storage=528 cf 0.72 cfs 0.54 cfs 0.03 cfs 0.51 cfs 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 32HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-1: Damon Road Drainage Inflow Area = 70,866 sf, 71.83% Impervious, Inflow Depth = 2.38" for 10-Year event Inflow = 4.57 cfs @ 12.12 hrs, Volume= 14,044 cf Primary = 4.57 cfs @ 12.12 hrs, Volume= 14,044 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-1: Damon Road Drainage Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)5 4 3 2 1 0 Inflow Area=70,866 sf 4.57 cfs 4.57 cfs 170334 - POST Type III 24-hr 10-Year Rainfall=4.50"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 33HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-2: Easterly flow Inflow Area = 9,579 sf, 0.02% Impervious, Inflow Depth = 1.08" for 10-Year event Inflow = 0.24 cfs @ 12.11 hrs, Volume=862 cf Primary = 0.24 cfs @ 12.11 hrs, Volume=862 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-2: Easterly flow Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)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=9,579 sf 0.24 cfs 0.24 cfs 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 34HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Time span=0.00-48.00 hrs, dt=0.05 hrs, 961 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=10,441 sf 70.14% Impervious Runoff Depth=4.90"Subcatchment PS-1A: Subcat PS-1A Tc=6.0 min CN=87 Runoff=1.30 cfs 4,264 cf Runoff Area=12,952 sf 71.41% Impervious Runoff Depth=4.90"Subcatchment PS-1B: Subcat PS-1B Tc=6.0 min CN=87 Runoff=1.62 cfs 5,290 cf Runoff Area=26,820 sf 75.66% Impervious Runoff Depth=5.12"Subcatchment PS-1C: Subcat PS-1C Tc=6.0 min CN=89 Runoff=3.45 cfs 11,451 cf Runoff Area=11,894 sf 45.07% Impervious Runoff Depth=3.93"Subcatchment PS-1D: Subcat PS-1D Tc=6.0 min CN=78 Runoff=1.23 cfs 3,900 cf Runoff Area=6,582 sf 98.75% Impervious Runoff Depth=6.16"Subcatchment PS-1E: Subcat PS-1E Tc=6.0 min CN=98 Runoff=0.93 cfs 3,379 cf Runoff Area=0.050 ac 100.00% Impervious Runoff Depth=6.16"Subcatchment PS-1F: Subcat PS-1F Tc=6.0 min CN=98 Runoff=0.31 cfs 1,118 cf Runoff Area=9,579 sf 0.02% Impervious Runoff Depth=2.28"Subcatchment PS-2: Subcat ES-2 Tc=6.0 min CN=61 Runoff=0.56 cfs 1,818 cf Peak Elev=147.36' Storage=1,897 cf Inflow=3.45 cfs 11,451 cfPond 1P: Bio Retention #1 Discarded=0.08 cfs 4,158 cf Primary=2.43 cfs 7,295 cf Outflow=2.52 cfs 11,453 cf Peak Elev=147.34' Storage=640 cf Inflow=1.23 cfs 3,900 cfPond 2P: Bio Retention #2 Discarded=0.04 cfs 1,532 cf Primary=1.03 cfs 2,368 cf Outflow=1.07 cfs 3,900 cf Inflow=7.43 cfs 23,715 cfLink DP-1: Damon Road Drainage Primary=7.43 cfs 23,715 cf Inflow=0.56 cfs 1,818 cfLink DP-2: Easterly flow Primary=0.56 cfs 1,818 cf Total Runoff Area = 80,445 sf Runoff Volume = 31,220 cf Average Runoff Depth = 4.66" 36.72% Pervious = 29,540 sf 63.28% Impervious = 50,905 sf 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 35HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1A: Subcat PS-1A Runoff = 1.30 cfs @ 12.09 hrs, Volume= 4,264 cf, Depth= 4.90" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Rainfall=6.40" Area (sf) CN Description 3,117 61 >75% Grass cover, Good, HSG B 7,324 98 Paved parking, HSG B 10,441 87 Weighted Average 3,117 29.86% Pervious Area 7,324 70.14% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1A: Subcat PS-1A Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 100-Year Rainfall=6.40" Runoff Area=10,441 sf Runoff Volume=4,264 cf Runoff Depth=4.90" Tc=6.0 min CN=87 1.30 cfs 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 36HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1B: Subcat PS-1B Runoff = 1.62 cfs @ 12.09 hrs, Volume= 5,290 cf, Depth= 4.90" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Rainfall=6.40" Area (sf) CN Description 3,703 61 >75% Grass cover, Good, HSG B 9,249 98 Paved parking, HSG B 0 98 Roofs, HSG B 12,952 87 Weighted Average 3,703 28.59% Pervious Area 9,249 71.41% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1B: Subcat PS-1B Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 100-Year Rainfall=6.40" Runoff Area=12,952 sf Runoff Volume=5,290 cf Runoff Depth=4.90" Tc=6.0 min CN=87 1.62 cfs 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 37HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1C: Subcat PS-1C Runoff = 3.45 cfs @ 12.09 hrs, Volume= 11,451 cf, Depth= 5.12" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Rainfall=6.40" Area (sf) CN Description 6,527 61 >75% Grass cover, Good, HSG B 20,293 98 Paved parking, HSG B 26,820 89 Weighted Average 6,527 24.34% Pervious Area 20,293 75.66% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1C: Subcat PS-1C Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)3 2 1 0 Type III 24-hr 100-Year Rainfall=6.40" Runoff Area=26,820 sf Runoff Volume=11,451 cf Runoff Depth=5.12" Tc=6.0 min CN=89 3.45 cfs 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 38HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1D: Subcat PS-1D Runoff = 1.23 cfs @ 12.09 hrs, Volume= 3,900 cf, Depth= 3.93" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Rainfall=6.40" Area (sf) CN Description 6,533 61 >75% Grass cover, Good, HSG B 5,361 98 Paved parking, HSG B 11,894 78 Weighted Average 6,533 54.93% Pervious Area 5,361 45.07% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1D: Subcat PS-1D Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 100-Year Rainfall=6.40" Runoff Area=11,894 sf Runoff Volume=3,900 cf Runoff Depth=3.93" Tc=6.0 min CN=78 1.23 cfs 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 39HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1E: Subcat PS-1E Runoff = 0.93 cfs @ 12.09 hrs, Volume= 3,379 cf, Depth= 6.16" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Rainfall=6.40" Area (sf) CN Description 82 61 >75% Grass cover, Good, HSG B 247 98 Paved parking, HSG B 6,252 98 Roofs, HSG B 6,582 98 Weighted Average 82 1.25% Pervious Area 6,500 98.75% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1E: Subcat PS-1E Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)1 0 Type III 24-hr 100-Year Rainfall=6.40" Runoff Area=6,582 sf Runoff Volume=3,379 cf Runoff Depth=6.16" Tc=6.0 min CN=98 0.93 cfs 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 40HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-1F: Subcat PS-1F Runoff = 0.31 cfs @ 12.09 hrs, Volume= 1,118 cf, Depth= 6.16" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Rainfall=6.40" Area (ac) CN Description 0.050 98 Roofs, HSG B 0.050 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-1F: Subcat PS-1F Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)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 100-Year Rainfall=6.40" Runoff Area=0.050 ac Runoff Volume=1,118 cf Runoff Depth=6.16" Tc=6.0 min CN=98 0.31 cfs 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 41HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Subcatchment PS-2: Subcat ES-2 Runoff = 0.56 cfs @ 12.10 hrs, Volume= 1,818 cf, Depth= 2.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Rainfall=6.40" Area (sf) CN Description 9,578 61 >75% Grass cover, Good, HSG B 1 98 Paved parking, HSG B 9,579 61 Weighted Average 9,578 99.98% Pervious Area 1 0.02% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PS-2: Subcat ES-2 Runoff Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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 100-Year Rainfall=6.40" Runoff Area=9,579 sf Runoff Volume=1,818 cf Runoff Depth=2.28" Tc=6.0 min CN=61 0.56 cfs 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 42HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Pond 1P: Bio Retention #1 Inflow Area = 26,820 sf, 75.66% Impervious, Inflow Depth = 5.12" for 100-Year event Inflow = 3.45 cfs @ 12.09 hrs, Volume= 11,451 cf Outflow = 2.52 cfs @ 12.17 hrs, Volume= 11,453 cf, Atten= 27%, Lag= 4.7 min Discarded = 0.08 cfs @ 12.17 hrs, Volume= 4,158 cf Primary = 2.43 cfs @ 12.17 hrs, Volume= 7,295 cf Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs / 2 Peak Elev= 147.36' @ 12.17 hrs Surf.Area= 3,562 sf Storage= 1,897 cf Plug-Flow detention time= 58.8 min calculated for 11,441 cf (100% of inflow) Center-of-Mass det. time= 59.0 min ( 845.1 - 786.1 ) Volume Invert Avail.Storage Storage Description #1 146.65' 2,028 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (feet) (cubic-feet) (cubic-feet)(sq-ft) 146.65 2,222 194.1 0 0 2,222 147.15 2,701 209.8 1,229 1,229 2,737 147.40 3,719 238.0 799 2,028 3,743 Device Routing Invert Outlet Devices #1 Primary 144.51'12.0" Round Culvert L= 62.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 144.51' / 144.20' S= 0.0050 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 146.95'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Discarded 146.65'1.020 in/hr Exfiltration over Wetted area Discarded OutFlow Max=0.08 cfs @ 12.17 hrs HW=147.36' (Free Discharge) 3=Exfiltration (Exfiltration Controls 0.08 cfs) Primary OutFlow Max=2.42 cfs @ 12.17 hrs HW=147.36' (Free Discharge) 1=Culvert (Passes 2.42 cfs of 4.58 cfs potential flow) 2=Orifice/Grate (Orifice Controls 2.42 cfs @ 3.08 fps) 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 43HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Pond 1P: Bio Retention #1 Inflow Outflow Discarded Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)3 2 1 0 Inflow Area=26,820 sf Peak Elev=147.36' Storage=1,897 cf 3.45 cfs 2.52 cfs 0.08 cfs 2.43 cfs 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 44HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Pond 2P: Bio Retention #2 Inflow Area = 11,894 sf, 45.07% Impervious, Inflow Depth = 3.93" for 100-Year event Inflow = 1.23 cfs @ 12.09 hrs, Volume= 3,900 cf Outflow = 1.07 cfs @ 12.14 hrs, Volume= 3,900 cf, Atten= 13%, Lag= 3.0 min Discarded = 0.04 cfs @ 12.14 hrs, Volume= 1,532 cf Primary = 1.03 cfs @ 12.14 hrs, Volume= 2,368 cf Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 147.34' @ 12.14 hrs Surf.Area= 1,510 sf Storage= 640 cf Plug-Flow detention time= 88.4 min calculated for 3,900 cf (100% of inflow) Center-of-Mass det. time= 88.3 min ( 904.7 - 816.4 ) Volume Invert Avail.Storage Storage Description #1 146.62'693 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet)(sq-ft) (feet) (cubic-feet) (cubic-feet)(sq-ft) 146.62 601 123.0 0 0 601 147.12 928 139.0 379 379 941 147.37 1,614 167.0 314 693 1,624 Device Routing Invert Outlet Devices #1 Primary 144.65'12.0" Round Culvert L= 89.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 144.65' / 144.20' S= 0.0051 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #2 Device 1 147.12'12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Discarded 146.62'1.020 in/hr Exfiltration over Wetted area Discarded OutFlow Max=0.04 cfs @ 12.14 hrs HW=147.33' (Free Discharge) 3=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=1.02 cfs @ 12.14 hrs HW=147.33' (Free Discharge) 1=Culvert (Passes 1.02 cfs of 4.25 cfs potential flow) 2=Orifice/Grate (Weir Controls 1.02 cfs @ 1.51 fps) 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 45HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Pond 2P: Bio Retention #2 Inflow Outflow Discarded Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)1 0 Inflow Area=11,894 sf Peak Elev=147.34' Storage=640 cf 1.23 cfs 1.07 cfs 0.04 cfs 1.03 cfs 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 46HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-1: Damon Road Drainage Inflow Area = 70,866 sf, 71.83% Impervious, Inflow Depth = 4.02" for 100-Year event Inflow = 7.43 cfs @ 12.10 hrs, Volume= 23,715 cf Primary = 7.43 cfs @ 12.10 hrs, Volume= 23,715 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-1: Damon Road Drainage Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (cfs)8 7 6 5 4 3 2 1 0 Inflow Area=70,866 sf 7.43 cfs 7.43 cfs 170334 - POST Type III 24-hr 100-Year Rainfall=6.40"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. Page 47HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Summary for Link DP-2: Easterly flow Inflow Area = 9,579 sf, 0.02% Impervious, Inflow Depth = 2.28" for 100-Year event Inflow = 0.56 cfs @ 12.10 hrs, Volume= 1,818 cf Primary = 0.56 cfs @ 12.10 hrs, Volume= 1,818 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.05 hrs Link DP-2: Easterly flow Inflow Primary Hydrograph Time (hours) 484644424038363432302826242220181614121086420Flow (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=9,579 sf 0.56 cfs 0.56 cfs Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Appendix D: Hydraulic Analysis Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Appendix E: MassDEP Calculations - Impervious Area Calculations - Required Recharge Volume - Water Quality Volume Calculations - Water Quality Volume Conversion to Flow Rate - Water Quality Conversion Table - Vortsentry Water Quality Unit Detail - MASTEP Tech Summary Report – Vortsentry Unit - Drawdown Calculations - TSS Removal Worksheet - Stage-Storage Chart – Bio-Retention Area #1 - Stage-Storage Chart – Bio-Retention Area #2 Proposed Commercial Development MassDEP Stormwater Standards Calculations 55 Damon Road Northampton, Massachusetts Standard 3: Recharge Calculations Impervious Area Calculations Existing Total Impervious Area Sub-Catchment Roof (sf) Other Impervious (sf) Sum (sf) ES-1 10992 49818 60810 ES-2 --0 10992 49818 60810 Proposed Total Impervious Area Sub-Catchment Roof (sf) Other Impervious (sf) Sum (sf) PS-1A -7324 7324 PS-1B -9249 9249 PS-1C -20293 20293 Tributary to Bio-Ret. #1 PS-1D -5361 5361 Tributary to Bio-Ret. #2 PS-1E 6252 247 6499 PS-1F 2193 -2193 PS-2 --0 8445 42474 50919 Summary Table 60810 SF 50919 SF 9891 SF Total Existing Impervious Area Total Proposed Impervious Area Total Reduction in Impervious Area Proposed Commercial Development MassDEP Stormwater Standards Calculations 55 Damon Road Northampton, Massachusetts Standard 3: Recharge Calculations RV (required) = F x Impervious Area where: RV = Required Recharge Volume (cu. ft.) F = Target Depth Factor 0.60 inch (A-soils) 0.35 inch (B-soils) 0.25 inch (C-soils) 0.10 inch (D-soils) Subsurface Basin: New Impervious Area by Hydrologic Soil Type Impervious Area (A-soils)0 sq. ft.0.0% Impervious Area (B-soils)50,919 sq. ft.100.0% Impervious Area (C-soils)0 sq. ft.0.0% Impervious Area (D-soils)0 sq. ft.0.0% Total Impervious area 50,919 sq. ft.100.0% Required Recharge Volume Sizing (RV): Bio-Retention Area #1 Tributary Imp. Area= 20,293 sq. ft. Rv (required) = ∑ [FSoil Type x Impervious AreaSoil Type] x 1 ft./12 in. Rv (required) =592 cu. ft. Required Recharge Volume Sizing (RV): Bio-Retention Area #2 Tributary Imp. Area= 5,361 sq. ft. Rv (required) = ∑ [FSoil Type x Impervious AreaSoil Type] x 1 ft./12 in. Rv (required) =156 cu. ft. Total Required Recharge Volume Sizing (RV)=748 cu. ft. Proposed Commercial Development MassDEP Stormwater Standards Calculations 55 Damon Road Northampton, Massachusetts Standard 4: Water Quality Water Quality Volume: Bio-Retention Area #1 VWQ = ( DWQ / 12 inches/foot ) ( AIMP x 43,560 square feet/acre ) where: VWQ = req'd water quality volume (cu. ft.) DWQ = water quality depth* (inches) = 0.5 inches AIMP = total impervious area (acres) = 0.466 acres (PS-1C) VWQ (required) = 592 cu. ft. 708 cu. ft. *Surface storage provided within bio-retention cell below overflow elevation. Water Quality Volume: Bio-Retention Area #2 VWQ = ( DWQ / 12 inches/foot ) ( AIMP x 43,560 square feet/acre ) where: VWQ = req'd water quality volume (cu. ft.) DWQ = water quality depth* (inches) = 0.5 inches AIMP = total impervious area (acres) = 0.123 acres (PS-1D) VWQ (required) = 156 cu. ft. 379 cu. ft. *Surface storage provided within bio-retention cell below overflow elevation. . Provided Storage= Provided Storage= Proposed Commercial Development MassDEP Stormwater Standards Calculations 55 Damon Road Northampton, Massachusetts Standard 4: Water Quality Water Quality Volume Conversion to Flow Rate Note: Required water quality volume based on 0.5-inch of runoff Q = (qu) (A) (WQV) where: Q = peak flow rate associated with first 0.5-inch of runoff (c.f.s.) qu = unit peak discharge (csm/in) - value taken from table based on tc A = impervious surface drainage area (sq. mi.) WQV = water quality volume in watershed inches (inch) · Proposed Water Quality Unit #1 - CDS 2015-4 tc =0.100 hrs qu =752 csm/in (from table) A =0.00033 sq. mi.* WQV =0.5 inch Q0.5 = 0.12 c.f.s** ** The Vortsentry HS36G provides treatment of flows up to 0.55 c.f.s. · Proposed Water Quality Unit #2 - Vortsentry HS36G tc =0.000 hrs qu =752 csm/in (from table) A =0.00023 sq. mi.* WQV =0.5 inch Q0.5 = 0.09 c.f.s** * Only includes area tributary to PWQU-2 ** The Vortsentry HS36G provides treatment of flows up to 0.55 c.f.s. * Only includes area tributary to PWQU-1 MassDEP Q Rate - Sept. 10, 2013 - Page 4 Figure 2: For First ½-inch of Runoff, Table of qu values for Ia/P Curve = 0.0.058, listed by tc, for Type III Storm Distribution Tc qu Tc qu Tc qu Tc qu (Hours) (csm/in) (Hours) (csm/in) (Hours) (csm/in) (Hours) (csm/in) 0.01 821 1.8 246 5.3 116 8.8 77 0.03 821 1.9 238 5.4 115 8.9 76 0.05 813 2 230 5.5 113 9 76 0.067 794 2.1 223 5.6 112 9.1 75 0.083 773 2.2 217 5.7 110 9.2 74 0.1 752 2.3 211 5.8 109 9.3 74 0.116 733 2.4 205 5.9 107 9.4 73 0.133 713 2.5 200 6 106 9.5 72 0.15 694 2.6 194 6.1 104 9.6 72 0.167 677 2.7 190 6.2 103 9.7 71 0.183 662 2.8 185 6.3 102 9.8 70 0.2 646 2.9 181 6.4 100 9.9 70 0.217 632 3 176 6.5 99 10 69 0.233 619 3.1 173 6.6 98 0.25 606 3.2 169 6.7 97 0.3 572 3.3 165 6.8 96 0.333 552 3.4 162 6.9 94 0.35 542 3.5 158 7 93 0.4 516 3.6 155 7.1 92 0.416 508 3.7 152 7.2 91 0.5 472 3.8 149 7.3 90 0.583 443 3.9 147 7.4 89 0.6 437 4 144 7.5 88 0.667 417 4.1 141 7.6 87 0.7 408 4.2 139 7.7 86 0.8 383 4.3 136 7.8 85 0.9 361 4.4 134 7.9 84 1 342 4.5 132 8 84 1.1 325 4.6 130 8.1 83 1.2 311 4.7 128 8.2 82 1.3 297 4.8 126 8.3 81 1.4 285 4.9 124 8.4 80 1.5 274 5 122 8.5 79 1.6 264 5.1 120 8.6 79 1.7 254 5.2 118 8.7 78 Water Resources Research Center Page 1 University of Massachusetts – Amherst 1/29/2009 UNIVERSITY OF MASSACHUSETTS AT AMHERST Water Resources Research Center Blaisdell House, UMass 310 Hicks Way Amherst, MA 01003 MASTEP Technology Review Massachusetts Stormwater Evaluation Project (413) 545-5532 (413) 545-2304 FAX www.mastep.net Technology Name: VortSentry HS Studies Reviewed: VortSentry® HS Performance Testing With OK-110.Tetreault, Heather Removal Characteristics of the VortSentry® Model HS48 using the F-55 Test Standard. Contech Stormwater Solutions Product Evaluation. Date: January 29, 2009 Reviewers: Sarah Titus, Jerry Schoen Rating: 2 Brief rationale for rating: These comments are based primarily on the Tetreault study, which is the stronger of the two. The Tetreault study is a lab test conducted by the manufacturer at their facility. Generally sound procedures were followed. Sediment mix tested is slightly larger than recommended by NJDEP, with no fines. No QAPP or quality control data. TARP Requirements Not Met*: • Not a third party study • No documentation of a Quality Assurance Project Plan, no QC data Other Comments • TSS removal efficiency, calculated according to the NJDEP weighted formula, was 69.6%. • Particle Size Distribution does not match the 55% sand, 40% silt, 5% clay mix recommended by NJDEP. OK-110 was used. This tested to a D50 of 105 microns, with no particles < 50 microns. Field conditions are variable with regard to solids characteristics, and comparison of this experiment to field-derived data will be accordingly affected. • A full range of flows (25% - 125%) was tested. • Scour test was performed. Some scour was observed at flows exceeding capacity (effluent concentrations ranged from 21 – 41 mf/l for washout conditions). • Influent TSS concentrations of 92-359 mg/l closely matched the recommended 100-300 mgl/l. * Criteria also based on NJDEP laboratory testing guidelines. Proposed Commercial Development MassDEP Stormwater Standards Calculations 55 Damon Road Northampton, Massachusetts Drawdown Analysis RV KA where: TDRAWDOWN = time in hours RV = required recharge volume (cu. ft.) K = Rawls rate 8.27 inches/hour (A-soils)* 1.02 inches/hour (B-soils)* 0.27 inches/hour (C-soils)* A = bottom area of recharge facility (sq. ft.) *Most conservative Rawls rate values for given soil type used for analysis purposes Bio-Retention Area #1 RV = 592 cu. ft. A = 2,222 sq. ft. TDRAWDOWN =3.1 hours < 72 hours (B-soils) Bio-Retention Area #2 RV = 156 cu. ft. A = 601 sq. ft. TDRAWDOWN =11.6 hours < 72 hours (B-soils) TDRAWDOWN = Proposed Commercial Development MassDEP Stormwater Standards Calculations 55 Damon Road Northampton, Massachusetts TSS Removal Form - Bio-Retention Areas BMP TSS Removal Starting TSS Amount Remaining Rate*Load Removed Load Total TSS Removal = 80% *TSS Removal Rate based on manufacturer information. TSS Removal Form - Vortsentry Pre-Treatment Units BMP TSS Removal Starting TSS Amount Remaining Rate** Load Removed Load Total TSS Removal** = 70% ** Based on information provided by MASTEP Review Focal Point 0.70 0.80 1.00 0.80 0.20 0.70 0.30Vortsentry HS36G Total TSS RemovalTotal TSS Removal1.00 Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 1P: Bio Retention #1 Elevation (feet) Surface (sq-ft) Wetted (sq-ft) Storage (cubic-feet) 146.65 2,222 2,222 0 146.67 2,240 2,242 45 146.69 2,259 2,262 90 146.71 2,277 2,282 135 146.73 2,296 2,302 181 146.75 2,314 2,322 227 146.77 2,333 2,342 273 146.79 2,351 2,362 320 146.81 2,370 2,382 367 146.83 2,389 2,403 415 146.85 2,408 2,423 463 146.87 2,427 2,444 511 146.89 2,446 2,464 560 146.91 2,465 2,485 609 146.93 2,484 2,505 659 146.95 2,504 2,526 708 146.97 2,523 2,547 759 146.99 2,543 2,568 809 147.01 2,562 2,588 860 147.03 2,582 2,609 912 147.05 2,601 2,630 964 147.07 2,621 2,652 1,016 147.09 2,641 2,673 1,069 147.11 2,661 2,694 1,122 147.13 2,681 2,715 1,175 147.15 2,701 2,737 1,229 147.17 2,776 2,812 1,284 147.19 2,853 2,889 1,340 147.21 2,931 2,967 1,398 147.23 3,009 3,045 1,457 147.25 3,089 3,124 1,518 147.27 3,169 3,204 1,581 147.29 3,251 3,285 1,645 147.31 3,334 3,366 1,711 147.33 3,418 3,448 1,778 147.35 3,502 3,532 1,847 147.37 3,588 3,616 1,918 147.39 3,675 3,700 1,991 Type III 24-hr 2-Year Rainfall=3.00"170334 - POST Printed 8/11/2017Prepared by R Levesque Associates Inc. HydroCAD® 10.00-20 s/n 02175 © 2017 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond 2P: Bio Retention #2 Elevation (feet) Surface (sq-ft) Wetted (sq-ft) Storage (cubic-feet) 146.62 601 601 0 146.64 613 614 12 146.66 625 627 25 146.68 637 640 37 146.70 649 653 50 146.72 661 666 63 146.74 673 679 76 146.76 685 692 90 146.78 698 705 104 146.80 711 719 118 146.82 723 732 132 146.84 736 745 147 146.86 749 759 162 146.88 762 773 177 146.90 775 786 192 146.92 789 800 208 146.94 802 814 224 146.96 816 828 240 146.98 829 842 256 147.00 843 856 273 147.02 857 870 290 147.04 871 884 307 147.06 885 898 325 147.08 899 912 343 147.10 914 927 361 147.12 928 941 379 147.14 976 991 398 147.16 1,025 1,042 418 147.18 1,075 1,093 439 147.20 1,127 1,146 461 147.22 1,180 1,199 484 147.24 1,234 1,253 509 147.26 1,289 1,308 534 147.28 1,345 1,364 560 147.30 1,403 1,420 588 147.32 1,462 1,477 616 147.34 1,522 1,535 646 147.36 1,583 1,594 677 Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Appendix F: Construction Period Erosion Control Plan R LEVESQUE ASSOCIATES, INC A L AND PL ANNING SERVICES COMPANY 40 School Street · Westfield, MA 01085 p 413.568.0985 · f 413.568.0986 · www.rlaland.com Construction Period Erosion Control Plan Proposed Commercial Development 55 Damon Road Northampton, MA 01060 Applicant: American Dream Realty c/o Mr. Emanuel Sardinha 16 Harvard Street Westfield, MA 01085 Owner: Robert S. Thomas 55 Damon Road Northampton, MA 01060 RLA Project File: 170334 August 10, 2017 Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 1 The project shall implement a construction period erosion control plan. The following provides descriptions and guidelines to ensure that the areas surrounding the project site will be protected from excessive sedimentation and runoff during construction. 1.1 Construction Period Pollution Prevention And Erosion Control Measures 1.1.1 Preconstruction Notifications And Meetings Prior to the start of construction, the contractor shall call together a pre-construction meeting including a representative from the City, the design engineer, contractor, and any pertinent persons that should be in attendance. These requirements shall be the responsibility of the Contractor to arrange, attend, and document. 1.1.2 Sediment Barrier And Work Limit Before installation of the sediment barriers, the location shall be staked in the field for review and approval by the owner or their representative. To facilitate sediment barrier installation, woody vegetation may then be removed and any required trench may be cut by machine, provided all other ground cover is left intact. No excavation, grading, filling, or removal of vegetative ground cover shall begin until sediment barriers have been installed as shown on the plans and have been inspected by the owner or their representative. 1.1.3 Silt Fence The bottom of the fence shall be trenched into the ground a minimum of 6" and back-filled with compacted soil. Where trenching is not feasible, silt fence skirt shall be covered with compacted soil or crushed stone. The top of the fabric shall be stretched as tightly as is practical, with intermediate stakes added to correct excessive sags. Stakes shall be driven at least 12" into the ground. Splices between sections shall be made by rolling end stakes together one complete turn and driving into the ground together. 1.1.4 Straw Bales Straw bales may be used as temporary and moveable control measures, temporary check dams, or as reinforcement for silt fence in areas of concentrated runoff or high fills. Bales shall be tightly butted and staked 12" into the ground. Where used without silt fence in front, the bales shall be trenched 4" into the ground, back-filled with compacted soil, and the spaces between bales shall be chinked with loose hay. 1.1.5 Filter Sock (Filtrexx Or Equivalent) In areas of expected sheet flow, filter sock may be placed directly on the ground without trenching or stakes. In areas of expected concentrated flow, mulch or crushed stone shall be placed along the up-slope face to control and filter underflow. Additional layers of Filter Sock may be required for adequate freeboard. The filter sock shall be staked at 10 feet on-center or in cases where they cannot be staked, utilize heavy concrete blocks to hold in place. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 2 1.1.6 Temporary Sedimentation Basins Temporary sediment basins may be excavations or bermed stormwater detention structures (depending on grading) that will retain runoff for a sufficient period of time to allow suspended soil particles to settle out prior to discharge. These temporary basins will be located based on construction needs as determined by the contractor and outlet devices will be designed to control velocity and sediment. Points of discharge from sediment basins will be stabilized to minimize erosion. If the temporary basin is to be located within an area of future infiltration as part of the stormwater management system, the excavation for the temporary sedimentation basin shall be limited to one foot above final grade of the infiltration structure. 1.1.7 Stocking Additional Materials A stock of additional erosion control materials shall be available on the site for emergency repairs and temporary measures. Stock shall be replenished when decreased to 50% of the numbers below. Stock shall include: Straw Bales – 10 (kept dry) with 20 oak stakes Or Silt Fence – 30 Linear feet. Or Filter Sock – 4 – 8 foot sections (kept dry) Washed Stone – One (1) cubic yard, ¾” to 2” diameter 1.1.8 Trench Protection Open trenches shall be protected from accumulation of surface water or groundwater that could result in erosion of the trench and discharge of sediment. Where feasible, spoil shall be stockpiled on the up-slope side of the trench to prevent entrance of surface runoff. Backfill shall be crowned to allow for settlement and to avoid concentration of runoff on top of the trench. 1.1.9 Site Stabilization – Temporary Where a portion of the site will not be subject to construction activity for over 14 days, measures shall be taken to provide temporary stabilization of that inactive portion of the site, within 14 days of the cessation of construction activity. Stabilization measures may include seeding for temporary cover, mulching, or other measures to protect exposed soil from erosion and prevent sediment movement. 1.1.10 Site Stabilization – Permanent Within 14 days of completion of loaming and finish grading on any portion of the site, that area shall be seeded or planted for permanent cover (season permitting) in accordance with USDA NRCS guidelines or equivalent. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 3 1.1.11 Roadway Sweeping The entrance to the site and affected portions of the access drive or paved project areas shall be swept as needed to control sediment runoff into storm drains or waterways and to control blowing dust. 1.2 Short-Term Erosion Control Maintenance The following provides short-term erosion control maintenance guidelines and requirements. 1. The contractor or subcontractor will be responsible for implementing each control shown on the sedimentation and erosion control plan. 2. All erosion and sediment control devices shall be properly maintained during all phases of construction until the completion of all construction activities and all disturbed areas have been stabilized. Additional control measures will be installed during construction in order to control erosion and/or off-site sedimentation if deemed necessary by on-site inspection. 3. Effective erosion control measures shall be initiated prior to the commencement of clearing, grading, excavation, or other operations that will disturb the natural protection. 4. All sediment and erosion control devices shall be inspected at least once every seven (7) calendar days and after any storm event greater than 0.5 inches of precipitation during any 24-hour period, and the inspection shall be documented in writing. Damaged or ineffective devices shall be repaired or replaced, as necessary. 5. The contractor shall take all reasonable precautions to avoid excess erosion of the site due to the construction of this project. 6. Silt shall be removed from behind barriers if greater than 6-inches deep or as needed. Sediment that is collected in structures shall be disposed of properly and covered if stored on-site 7. Damaged or deteriorated items will be repaired immediately after identification. 8. All ditches shall be stabilized as soon as is practicable to minimize erosion. 9. The contractor shall maintain all erosion control devices in a good, working state of repair. Upon complete stabilization of any tributary areas, the erosion control devices shall be removed and disposed of so as to cause no off-site siltation. 10. Inspect and maintain construction entrance stone such that sediment does not track onto the street. Any sediment tracked onto the street shall be swept daily. 11. After catch basins have been constructed, the contractor shall protect the inlets by constructing inlet protection as shown on the plans. 12. Once the site has been paved, all catch basin inlets shall receive a silt sack type protection. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 4 13. Erosion control measures shall remain in place until all disturbed earth has been substantially stabilized. After removal of structures, disturbed areas shall be regraded and stabilized as necessary. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Appendix G: Long-Term Operation and Maintenance Plan - Long-Term Operation & Maintenance Plan Narrative - Vortsentry Inspection and Maintenance Guide - FocalPoint Biofiltration System Operation and Maintenance Guide - O&M Checklist R LEVESQUE ASSOCIATES, INC A L AND PL ANNING SERVICES COMPANY 40 School Street · Westfield, MA 01085 p 413.568.0985 · f 413.568.0986 · www.rlaland.com Long-Term Operation & Maintenance Plan Proposed Commercial Development 55 Damon Road Northampton, MA 01060 Applicant: American Dream Realty c/o Mr. Emanuel Sardinha 16 Harvard Street Westfield, MA 01085 Owner: Robert S. Thomas 55 Damon Road Northampton, MA 01060 RLA Project File: 170334 August 10, 2017 Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 2 1. Long-Term Stormwater Maintenance Program: This Long-Term Operation and Maintenance Plan (O&M) identifies inspection and maintenance requirements for the proposed stormwater management system. The O&M references guidelines set forth by the Stormwater Management Handbook developed by the Massachusetts Department of Environmental Protection. Owner: American Dream Realty c/o Mr. Emanuel Sardinha 16 Harvard Street Westfield, MA 01085 Responsible Party*: American Dream Realty c/o Mr. Emanuel Sardinha 16 Harvard Street Westfield, MA 01085 *The party listed shall be responsible for implementation and record keeping of the requirements listed in this operation and maintenance plan. Upon sale of property or any other transition of ownership, the responsible party shall be reinstated as the new owner or any other group created as determined by the owner. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 3 2. Inspection and Maintenance Program: Regular inspection and routine maintenance are necessary to ensure that the stormwater management system continues to control and treat runoff. The following lists the inspection schedule and maintenance procedures for the proposed stormwater Best Management Practices: BMP Inspection Schedule Maintenance Schedule Maintenance Procedures Bituminous Concrete Pavement Four times per year Twice per year  Roadway to be swept in March or April following snow melt and again in late November or early December to remove fallen leaves and debris Bio-Retention Areas Once per month Twice per year (Spring and Fall)  Inspect bio-retention areas for sediment build-up, structural damage, and standing water;  Inspect and repair eroded areas monthly;  Re-mulch void areas as needed;  Remove litter and debris monthly;  Treat diseased or distressed vegetation as needed;  Remove and replace dead vegetation twice per year (Spring and Fall);  Remove invasive species as needed;  Replace mulch every two years. Stormwater Piping Once per year Once per year  Inspect pipe entrances in catch basins and manholes and remove any blockages Roof Leaders Once per year Once per year  Inspect downspout connections at grade and remove any blockages  Open and inspect cleanout locations and remove any blockages Proprietary Sedimentation Device* As specified by the manufacturer As specified by the manufacturer  Clean the unit using the method specified by the manufacturer. Vactor trucks are typically used to clean these units. *See attached Device Operation and Maintenance Guides **See attached Isolator Row O&M Manual See the attached Long-Term O&M Inspection Checklist for record keeping purposes. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 4 3. Additional Long-Term Operation and Maintenance Items The following is a list of additional operation and maintenance items to be implemented by the owner/governing group to maintain the features proposed in this project. A. Proper storage, use, and disposal of hazardous chemicals, including automobile fluids, pesticides, paints, solvents, etc. shall be required. Information should be provided on chemicals of concern, proper use, and disposal options. Recycling programs for used motor oil, antifreeze, and other products should be developed. B. Vehicle Washing. This management measure involves educating the owner on the water quality impacts of the outdoor washing of vehicles and how to avoid allowing polluted runoff to enter the storm drain system. Outdoor vehicle washing has the potential to result in high loads of nutrients, metals, and hydrocarbons which is conveyed by the detergent-rich water into storm drains. C. Recycling, spill prevention and response plans, and proper material storage and disposal of potentially hazardous materials shall be implemented. It will be the responsibility of the owner to contain and legally remove any materials that are spilled onsite. The use of dry floor cleaners and absorbent materials and limiting the use of water to clean pavement is encouraged. Care should be taken to avoid accidental disposal of hazardous materials. D. Provisions for storing trash and waste products shall be implemented. The waste materials shall be collected by the owner and all materials shall be properly disposed of. E. Requirements for routine inspections and maintenance of stormwater best management practices. Routine inspections shall be performed to ensure the correct functioning of stormwater best management practices. See the specific maintenance criteria for detail regarding inspections and maintenance frequency. F. Requirements for Storage and Use of Fertilizers, Herbicides, and Pesticides. Fertilizers, pesticides, herbicides, lawn care chemicals, or other leachable materials shall be used in accordance with the Lawn Care Regulations of the Massachusetts Pesticide Board, 33 CMR 10.03 (30,31), as amended, with manufacturer’s label instructions and all other necessary precautions to minimize adverse impacts on surface and groundwater. The storage of any such materials shall be within structure designed to prevent the escape of contaminated runoff or leachate. G. Provisions for prevention of illicit discharges to the stormwater management system shall be implemented. Any illicit discharges to the stormwater management system shall be prohibited. It will be the owner’s responsibility to ensure compliance with the legal disposal of all materials and containment/cleanup of any illicit discharges. H. Training for staff or personnel involved with implementation of the Long-Term Pollution Prevention Plan shall be required. The owner/governing group will be responsible for the implementation of the measures set forth in the Long-Term Pollution Prevention Plan. Documentation that personnel and owners involved with the implementation of the Long-Term Pollution Prevention Plan have been trained to conduct such tasks shall be documented. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 5 4. Winter and Snow Conditions The following is a list of additional operation and maintenance items to be implemented by the owner during winter and snow conditions. A. Snowfall shall be stored on the grassed areas surrounding the pavement areas, excluding any areas utilized for stormwater management practices. As needed, any snow that cannot be stored on site shall be trucked off site and disposed of properly. B. Winter road salt and/or sand use and storage restrictions shall be implemented based on any restrictions issued for the project. Sodium chloride for ice control shall be used at the minimum salt to sand ratio which is consistent with the Massachusetts Department of Environmental Protections guidelines. Sodium chloride, calcium chloride, chemically treated abrasives or other chemicals used for the removal of ice and snow on roads/drives shall not be stored on site. 5. Public Safety Features The proposed site design utilizes the following features which have been incorporated to ensure the safety of the public: A. Control and collection of stormwater runoff through positive drainage and curbing directing it towards the drainage inlets; B. Heavy-duty stormwater drain manhole covers and catch basin grates have been designed to withstand H20 loading; C. Reduction of peak discharge rates from the site in the post-development condition as compared to the pre-developed conditions; D. Development and implementation of an Operations & Maintenance Plan to ensure the stormwater management system continues to function as designed. Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Page 6 6. Estimated Cost of Maintenance The following budget was prepared as an estimate of inspection and maintenance costs for the stormwater management system. The budget is an estimate only as the costs may vary depending on the level of sediment accumulation and frequency of maintenance tasks required. BMP Inspections Number of Occurrences Maintenance Cost Number of Structures Sum Bio-Retention Areas 12/year $50 2 $1,200 Vortsentry Water Quality Unit 2/year $100 2 $200 Total Estimated Annual Cost of Inspections $2,800 BMP Maintenance Number of Occurrences Maintenance Cost Number of Structures Sum Bio-Retention Areas 2/year $75 2 $600 Vortsentry Water Quality Unit 2/year $800 2 $1,600 Total Estimated Annual Cost of Maintenance $2,200 VortSentry® HS Maintenance The VortSentry HS system should be inspected at regular intervals and maintained when necessary to ensure optimum performance. The rate at which the system collects pollutants will depend more heavily on site activities than the size of the unit, i.e., unstable soils or heavy winter sanding will cause the treatment chamber to fi ll more quickly, but regular sweeping will slow accumulation. Inspection Inspection is the key to effective maintenance and is easily performed. Pollutant deposition and transport may vary from year to year and regular inspections will help ensure that the system is cleaned out at the appropriate time. At a minimum, inspections should be performed twice per year (i.e. spring and fall) however more frequent inspections may be necessary in equipment washdown areas and in climates where winter sanding operations may lead to rapid accumulations of a large volume of sediment. It is useful and often required as part of a permit to keep a record of each inspection. A simple inspection and maintenance log form for doing so is available for download at www.contechstormwater.com. The VortSentry HS should be cleaned when the sediment has accumulated to a depth of two feet in the treatment chamber. This determination can be made by taking two measurements with a stadia rod or similar measuring device; one measurement from the manhole opening to the top of the sediment pile and the other from the manhole opening to the water surface. If the difference between these measurements is less than the distance given in Table 1, the VortSentry HS should be maintained to ensure effective treatment. Cleaning Cleaning of the VortSentry HS should be done during dry weather conditions when no fl ow is entering the system. Cleanout of the VortSentry HS with a vacuum truck is generally the most effective and convenient method of excavating pollutants from the system. Simply remove the manhole cover and insert the vacuum hose into the sump. All pollutants can be removed from this one access point from the surface with no requirements for Confi ned Space Entry. In installations where the risk of petroleum spills is small, liquid contaminants may not accumulate as quickly as sediment. However, an oil or gasoline spill should be cleaned out immediately. Motor oil and other hydrocarbons that accumulate on a more routine basis should be removed when an appreciable layer has been captured. To remove these pollutants, it may be preferable to use adsorbent pads, which solidify the oils. These are usually much easier to remove from the unit individually, and less expensive to dispose than the oil/water emulsion that may be created by vacuuming the oily layer. Floating trash can be netted out if you wish to separate it from the other pollutants. Manhole covers should be securely seated following cleaning activities to prevent leakage of runoff into the system from above and also to ensure proper safety precautions. If anyone physically enters the unit, Confi ned Space Entry procedures need to be followed. Disposal of all material removed from the VortSentry HS should be done is accordance with local regulations. In many locations, disposal of evacuated sediments may be handled in the same manner as disposal of sediments removed from catch basins or deep sump manholes. Check your local regulations for specifi c requirements on disposal. Table 1: VortSentry HS Maintenance Indicators and Sediment Storage Capacities. Distance VortSentry HS Diameter Between Water Sediment Oil Spill Model Surface and Top Storage Storage of Storage Sump in. m ft. m yd3 m3 gal. liter HS36 36 0.9 3.6 1.1 0.5 0.4 83 314 HS48 48 1.2 4.7 1.4 0.9 0.7 158 598 HS60 60 1.5 6.0 1.8 1.5 1.1 258 978 HS72 72 1.8 7.1 2.2 2.1 1.6 372 1409 HS84 84 2.1 8.4 2.6 2.9 2.2 649 2458 HS96 96 2.4 9.5 2.9 3.7 2.8 845 3199 1. The water depth to sediment is determined by taking two measurements with a stadia rod: one measurement from the manhole opening to the top of the sediment pile and the other from the manhole opening to the water surface. If the difference between these measurements is less than the distance given in Table 1, the system should be cleaned out. Note: To avoid underestimating the volume of sediment in the chamber, the measuring device must be carefully lowered to the top of the sediment pile. 2. For optimum performance, the system should be cleaned out when the fl oating hydrocarbon layer accumulates to an appreciable thickness. In the event of an oil spill, the system should be cleaned immediately. VortSentry HS Inspection & Maintenance Log VortSentry HS Model: Location: Water Floatable Describe Maintenance Date depth to Layer Maintenance Personnel Comments shipment1 Thickness2 Performed —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— Operations & Maintenance GENERAL DESCRIPTION The following general specications describe the general operations and maintenance requirements for the FocalPoint® High Performance Modular Bioltration System (HPMBS). The system utilizes physical, chemical and biological mechanisms of a soil, plant and microbe complex to remove pollutants typically found in urban stormwater runo. The treatment system is a fully equipped, modular, constructed in place system designed to treat contaminated runo. Stormwater enters the HPMBS, is ltered by the High Performance Bioltration Media and passes through to the underdrain/storage system where the treated water is detained, retained or inltrated to sub-soils, prior to discharge to the storm sewer system of any remaining ow. Higher ows bypass the FocalPoint® via a downstream inlet or other overow conveyance. Maintenance is a simple, inexpensive and safe operation that does not require conned space entry, pumping or vacuum equipment, or specialized tools. Properly trained landscape personnel can eectively maintain FocalPoint® Stormwater systems by following instructions in this manual. (p) 800.711.5428 | www.convergentwater.com BASIC OPERATIONS FocalPoint® is a modular, high performance bioltration system that often works in tandem with other integrated management practices (IMP). Contaminated stormwater runo enters the bioltration bed through a conveyance swale, planter box, or directly through a curb cut or false inlet. Energy is dissipated by a rock or vegetative dissipation device and is absorbed by a 3-inch layer of aged, double shreddded hardwood mulch, with nes removed, (when specied) on the surface of the bioltration media. As the water passes through the mulch layer, most of the larger sediment particles and heavy metals are removed through sedimentation and chemical reactions with the organic material in the mulch. Water passes through the bioltration media where the ner particles are removed and numerous chemical reactions take place to immobilize and capture pollutants in the soil media. The cleansed water passes into the underdrain/storage system and remaining ows are directed to a storm sewer system or other appropriate discharge point. Once the pollutants are in the soil, bacteria begin to break down and metabolize the materials and the plants begin to uptake and metabolize the pollutants. Some pollutants such as heavy metals, which are chemically bound to organic particles in the mulch, are released over time as the organic matter decomposes to release the metals to the feeder roots of the plants and the cells of the bacteria in the soil where they remain and are recycled. Other pollutants such as phosphorus are chemically bound to the soil particles and released slowly back to the plants and bacteria and used in their metabolic processes. Nitrogen goes through a variety of very complex biochemical processes where it can ultimately end up in the plant/bacteria biomass, turned to nitrogen gas or dissolves back into the water column as nitrates depending on soil temperature, pH and the availability of oxygen. The pollutants ultimately are retained in the mulch, soil and biomass with some passing out of the system into the air or back into the water. DESIGN AND INSTALLATION Each project presents dierent scopes for the use of FocalPoint® system. To ensure the safe and specied function of this stormwater BMP, Convergent Water Technologies and/or its Value Added Resellers (VAR) review each application before supply. Information and design assistance is available to the design engineer during the planning process. Correct FocalPoint® sizing is essential to optimum performance. The engineer shall submit calculations for approval by the local jurisdiction when required. The contractor and/or VAR is responsible for the correct installation of FocalPoint units as described in approved plans. A comprehensive installation manual is available at www.convergentwater.com. MAINTENANCE Why Maintain? All stormwater treatment systems require maintenance for eective operation. This necessity is often incorporated in your property’s permitting process as a legally binding BMP maintenance agreement. Other reasons for maintenance include: • Avoid legal challenges from your jurisdiction’s maintenance enforcement program. • Prolong the lifespan of your FocalPoint HPMBS. • Avoid costly repairs. • Help reduce pollutant loads leaving your property. Simple maintenance of the FocalPoint® is required to continue eective pollutant removal from stormwater runo before any discharge into downstream waters. This procedure will also extend the longevity of the living bioltration system. The unit will recycle and accumulate pollutants within the biomass, but may also subjected to other materials entering the surface of the system. This may include trash, silt and leaves etc. which will be contained above the mulch and/or bioltration media layer. Too much silt may inhibit the FocalPoint’s® ow rate, which is a primary reason for system maintenance. Removal of accumulated silt/sediment and/or replacement of the mulch layer (when specied), is an important activity that prevents overaccumulation of such silt/sediment. When to Maintain? Convergent Water Technologies and/or its VAR includes a 1-year maintenance plan with each system purchased. Annual included maintenance consists of two (2) scheduled maintenance visits. Additional maintenance may be necessary depending on sediment and trash loading (by Owner or at additional cost). The start of the maintenance plan begins when the system is activated for full operation. Full operation is dened as when the site is appropriately stabilized, the unit is installed and activated (by VAR), i.e., when mulch (if specied) and plantings are added. Activation should be avoided until the site is fully stabilized (full landscaping, grass cover, nal paving and street sweeping completed). Maintenance visits are scheduled seasonally; the spring visit aims to clean up after winter loads including salts and sands. The fall visit helps the system by removing excessive leaf litter. A rst inspection to determine if maintenance is necessary should be performed at least twice annually after storm events of greater than (1) one inch total depth (subject to regional climate). Please refer to the maintenance checklist for specic conditions that indicate if maintenance is necessary. It has been found that in regions which receive between 30-50 inches of annual rainfall, (2) two visits are generally required. Regions with less rainfall often only require (1) one visit per annum. Varying land uses can aect maintenance frequency. Some sites may be subjected to extreme sediment or trash loads, requiring more frequent maintenance visits. This is the reason for detailed notes of maintenance actions per unit, helping the VAR/Maintenance contractor and Owner predict future maintenance frequencies, reecting individual site conditions. Owners must promptly notify the VAR/Maintenance contractor of any damage to the plant(s), which constitute(s) an integral part of the bioltration technology. Owners should also advise other landscape or maintenance contractors to leave all maintenance of the HPMBS to the VAR/Maintenance contractor (i.e. no pruning or fertilizing). EXCLUSION OF SERVICES It is the responsibility of the owner to provide adequate irrigation when necessary to the plant(s) in the FocalPoint® system. Clean up due to major contamination such as oils, chemicals, toxic spills, etc. will result in additional costs and are not covered under the VAR/Maintenance contractor maintenance contract. Should a major contamination event occur, the Owner must block o the outlet pipe of the FocalPoint® (where the cleaned runo drains to, such as drop-inlet) and block o the point where water enters of the FocalPoint®. The VAR/Maintenance contractor should be informed immediately. MAINTENANCE VISIT SUMMARY Each maintenance visit consists of the following simple tasks (detailed instructions below). 1. Inspection of FocalPoint® and surrounding area 2. Removal of debris, trash and mulch 3. Mulch replacement 4. Plant health evaluation (including measurements) and pruning or replacement as necessary 5. Clean area around FocalPoint® 6. Complete paperwork, including date stamped photos of the tasks listed above. MAINTENANCE TOOLS, SAFETY EQUIPMENT AND SUPPLIES Ideal tools include: camera, bucket, shovel, broom, pruners, hoe/rake, and tape measure. Appropriate Personal Protective Equipment (PPE) should be used in accordance with local or company procedures. This may include impervious gloves where the type of trash is unknown, high visibility clothing and barricades when working in close proximity to trac and also safety hats and shoes. MAINTENANCE VISIT PROCEDURE (p) 800.711.5428 | www.convergentwater.com BASIC OPERATIONS FocalPoint® is a modular, high performance bioltration system that often works in tandem with other integrated management practices (IMP). Contaminated stormwater runo enters the bioltration bed through a conveyance swale, planter box, or directly through a curb cut or false inlet. Energy is dissipated by a rock or vegetative dissipation device and is absorbed by a 3-inch layer of aged, double shreddded hardwood mulch, with nes removed, (when specied) on the surface of the bioltration media. As the water passes through the mulch layer, most of the larger sediment particles and heavy metals are removed through sedimentation and chemical reactions with the organic material in the mulch. Water passes through the bioltration media where the ner particles are removed and numerous chemical reactions take place to immobilize and capture pollutants in the soil media. The cleansed water passes into the underdrain/storage system and remaining ows are directed to a storm sewer system or other appropriate discharge point. Once the pollutants are in the soil, bacteria begin to break down and metabolize the materials and the plants begin to uptake and metabolize the pollutants. Some pollutants such as heavy metals, which are chemically bound to organic particles in the mulch, are released over time as the organic matter decomposes to release the metals to the feeder roots of the plants and the cells of the bacteria in the soil where they remain and are recycled. Other pollutants such as phosphorus are chemically bound to the soil particles and released slowly back to the plants and bacteria and used in their metabolic processes. Nitrogen goes through a variety of very complex biochemical processes where it can ultimately end up in the plant/bacteria biomass, turned to nitrogen gas or dissolves back into the water column as nitrates depending on soil temperature, pH and the availability of oxygen. The pollutants ultimately are retained in the mulch, soil and biomass with some passing out of the system into the air or back into the water. DESIGN AND INSTALLATION Each project presents dierent scopes for the use of FocalPoint® system. To ensure the safe and specied function of this stormwater BMP, Convergent Water Technologies and/or its Value Added Resellers (VAR) review each application before supply. Information and design assistance is available to the design engineer during the planning process. Correct FocalPoint® sizing is essential to optimum performance. The engineer shall submit calculations for approval by the local jurisdiction when required. The contractor and/or VAR is responsible for the correct installation of FocalPoint units as described in approved plans. A comprehensive installation manual is available at www.convergentwater.com. MAINTENANCE Why Maintain? All stormwater treatment systems require maintenance for eective operation. This necessity is often incorporated in your property’s permitting process as a legally binding BMP maintenance agreement. Other reasons for maintenance include: • Avoid legal challenges from your jurisdiction’s maintenance enforcement program. • Prolong the lifespan of your FocalPoint HPMBS. • Avoid costly repairs. • Help reduce pollutant loads leaving your property. Simple maintenance of the FocalPoint® is required to continue eective pollutant removal from stormwater runo before any discharge into downstream waters. This procedure will also extend the longevity of the living bioltration system. The unit will recycle and accumulate pollutants within the biomass, but may also subjected to other materials entering the surface of the system. This may include trash, silt and leaves etc. which will be contained above the mulch and/or bioltration media layer. Too much silt may inhibit the FocalPoint’s® ow rate, which is a primary reason for system maintenance. Removal of accumulated silt/sediment and/or replacement of the mulch layer (when specied), is an important activity that prevents overaccumulation of such silt/sediment. When to Maintain? Convergent Water Technologies and/or its VAR includes a 1-year maintenance plan with each system purchased. Annual included maintenance consists of two (2) scheduled maintenance visits. Additional maintenance may be necessary depending on sediment and trash loading (by Owner or at additional cost). The start of the maintenance plan begins when the system is activated for full operation. Full operation is dened as when the site is appropriately stabilized, the unit is installed and activated (by VAR), i.e., when mulch (if specied) and plantings are added. Activation should be avoided until the site is fully stabilized (full landscaping, grass cover, nal paving and street sweeping completed). Maintenance visits are scheduled seasonally; the spring visit aims to clean up after winter loads including salts and sands. The fall visit helps the system by removing excessive leaf litter. A rst inspection to determine if maintenance is necessary should be performed at least twice annually after storm events of greater than (1) one inch total depth (subject to regional climate). Please refer to the maintenance checklist for specic conditions that indicate if maintenance is necessary. It has been found that in regions which receive between 30-50 inches of annual rainfall, (2) two visits are generally required. Regions with less rainfall often only require (1) one visit per annum. Varying land uses can aect maintenance frequency. Some sites may be subjected to extreme sediment or trash loads, requiring more frequent maintenance visits. This is the reason for detailed notes of maintenance actions per unit, helping the VAR/Maintenance contractor and Owner predict future maintenance frequencies, reecting individual site conditions. Owners must promptly notify the VAR/Maintenance contractor of any damage to the plant(s), which constitute(s) an integral part of the bioltration technology. Owners should also advise other landscape or maintenance contractors to leave all maintenance of the HPMBS to the VAR/Maintenance contractor (i.e. no pruning or fertilizing). EXCLUSION OF SERVICES It is the responsibility of the owner to provide adequate irrigation when necessary to the plant(s) in the FocalPoint® system. Clean up due to major contamination such as oils, chemicals, toxic spills, etc. will result in additional costs and are not covered under the VAR/Maintenance contractor maintenance contract. Should a major contamination event occur, the Owner must block o the outlet pipe of the FocalPoint® (where the cleaned runo drains to, such as drop-inlet) and block o the point where water enters of the FocalPoint®. The VAR/Maintenance contractor should be informed immediately. MAINTENANCE VISIT SUMMARY Each maintenance visit consists of the following simple tasks (detailed instructions below). 1. Inspection of FocalPoint® and surrounding area 2. Removal of debris, trash and mulch 3. Mulch replacement 4. Plant health evaluation (including measurements) and pruning or replacement as necessary 5. Clean area around FocalPoint® 6. Complete paperwork, including date stamped photos of the tasks listed above. MAINTENANCE TOOLS, SAFETY EQUIPMENT AND SUPPLIES Ideal tools include: camera, bucket, shovel, broom, pruners, hoe/rake, and tape measure. Appropriate Personal Protective Equipment (PPE) should be used in accordance with local or company procedures. This may include impervious gloves where the type of trash is unknown, high visibility clothing and barricades when working in close proximity to trac and also safety hats and shoes. MAINTENANCE VISIT PROCEDURE (p) 800.711.5428 | www.convergentwater.com BASIC OPERATIONS FocalPoint® is a modular, high performance bioltration system that often works in tandem with other integrated management practices (IMP). Contaminated stormwater runo enters the bioltration bed through a conveyance swale, planter box, or directly through a curb cut or false inlet. Energy is dissipated by a rock or vegetative dissipation device and is absorbed by a 3-inch layer of aged, double shreddded hardwood mulch, with nes removed, (when specied) on the surface of the bioltration media. As the water passes through the mulch layer, most of the larger sediment particles and heavy metals are removed through sedimentation and chemical reactions with the organic material in the mulch. Water passes through the bioltration media where the ner particles are removed and numerous chemical reactions take place to immobilize and capture pollutants in the soil media. The cleansed water passes into the underdrain/storage system and remaining ows are directed to a storm sewer system or other appropriate discharge point. Once the pollutants are in the soil, bacteria begin to break down and metabolize the materials and the plants begin to uptake and metabolize the pollutants. Some pollutants such as heavy metals, which are chemically bound to organic particles in the mulch, are released over time as the organic matter decomposes to release the metals to the feeder roots of the plants and the cells of the bacteria in the soil where they remain and are recycled. Other pollutants such as phosphorus are chemically bound to the soil particles and released slowly back to the plants and bacteria and used in their metabolic processes. Nitrogen goes through a variety of very complex biochemical processes where it can ultimately end up in the plant/bacteria biomass, turned to nitrogen gas or dissolves back into the water column as nitrates depending on soil temperature, pH and the availability of oxygen. The pollutants ultimately are retained in the mulch, soil and biomass with some passing out of the system into the air or back into the water. DESIGN AND INSTALLATION Each project presents dierent scopes for the use of FocalPoint® system. To ensure the safe and specied function of this stormwater BMP, Convergent Water Technologies and/or its Value Added Resellers (VAR) review each application before supply. Information and design assistance is available to the design engineer during the planning process. Correct FocalPoint® sizing is essential to optimum performance. The engineer shall submit calculations for approval by the local jurisdiction when required. The contractor and/or VAR is responsible for the correct installation of FocalPoint units as described in approved plans. A comprehensive installation manual is available at www.convergentwater.com. MAINTENANCE Why Maintain? All stormwater treatment systems require maintenance for eective operation. This necessity is often incorporated in your property’s permitting process as a legally binding BMP maintenance agreement. Other reasons for maintenance include: • Avoid legal challenges from your jurisdiction’s maintenance enforcement program. • Prolong the lifespan of your FocalPoint HPMBS. • Avoid costly repairs. • Help reduce pollutant loads leaving your property. Simple maintenance of the FocalPoint® is required to continue eective pollutant removal from stormwater runo before any discharge into downstream waters. This procedure will also extend the longevity of the living bioltration system. The unit will recycle and accumulate pollutants within the biomass, but may also subjected to other materials entering the surface of the system. This may include trash, silt and leaves etc. which will be contained above the mulch and/or bioltration media layer. Too much silt may inhibit the FocalPoint’s® ow rate, which is a primary reason for system maintenance. Removal of accumulated silt/sediment and/or replacement of the mulch layer (when specied), is an important activity that prevents overaccumulation of such silt/sediment. When to Maintain? Convergent Water Technologies and/or its VAR includes a 1-year maintenance plan with each system purchased. Annual included maintenance consists of two (2) scheduled maintenance visits. Additional maintenance may be necessary depending on sediment and trash loading (by Owner or at additional cost). The start of the maintenance plan begins when the system is activated for full operation. Full operation is dened as when the site is appropriately stabilized, the unit is installed and activated (by VAR), i.e., when mulch (if specied) and plantings are added. Activation should be avoided until the site is fully stabilized (full landscaping, grass cover, nal paving and street sweeping completed). Maintenance visits are scheduled seasonally; the spring visit aims to clean up after winter loads including salts and sands. The fall visit helps the system by removing excessive leaf litter. A rst inspection to determine if maintenance is necessary should be performed at least twice annually after storm events of greater than (1) one inch total depth (subject to regional climate). Please refer to the maintenance checklist for specic conditions that indicate if maintenance is necessary. It has been found that in regions which receive between 30-50 inches of annual rainfall, (2) two visits are generally required. Regions with less rainfall often only require (1) one visit per annum. Varying land uses can aect maintenance frequency. Some sites may be subjected to extreme sediment or trash loads, requiring more frequent maintenance visits. This is the reason for detailed notes of maintenance actions per unit, helping the VAR/Maintenance contractor and Owner predict future maintenance frequencies, reecting individual site conditions. Owners must promptly notify the VAR/Maintenance contractor of any damage to the plant(s), which constitute(s) an integral part of the bioltration technology. Owners should also advise other landscape or maintenance contractors to leave all maintenance of the HPMBS to the VAR/Maintenance contractor (i.e. no pruning or fertilizing). EXCLUSION OF SERVICES It is the responsibility of the owner to provide adequate irrigation when necessary to the plant(s) in the FocalPoint® system. Clean up due to major contamination such as oils, chemicals, toxic spills, etc. will result in additional costs and are not covered under the VAR/Maintenance contractor maintenance contract. Should a major contamination event occur, the Owner must block o the outlet pipe of the FocalPoint® (where the cleaned runo drains to, such as drop-inlet) and block o the point where water enters of the FocalPoint®. The VAR/Maintenance contractor should be informed immediately. MAINTENANCE VISIT SUMMARY Each maintenance visit consists of the following simple tasks (detailed instructions below). 1. Inspection of FocalPoint® and surrounding area 2. Removal of debris, trash and mulch 3. Mulch replacement 4. Plant health evaluation (including measurements) and pruning or replacement as necessary 5. Clean area around FocalPoint® 6. Complete paperwork, including date stamped photos of the tasks listed above. MAINTENANCE TOOLS, SAFETY EQUIPMENT AND SUPPLIES Ideal tools include: camera, bucket, shovel, broom, pruners, hoe/rake, and tape measure. Appropriate Personal Protective Equipment (PPE) should be used in accordance with local or company procedures. This may include impervious gloves where the type of trash is unknown, high visibility clothing and barricades when working in close proximity to trac and also safety hats and shoes. MAINTENANCE VISIT PROCEDURE (p) 800.711.5428 | www.convergentwater.com BASIC OPERATIONS FocalPoint® is a modular, high performance bioltration system that often works in tandem with other integrated management practices (IMP). Contaminated stormwater runo enters the bioltration bed through a conveyance swale, planter box, or directly through a curb cut or false inlet. Energy is dissipated by a rock or vegetative dissipation device and is absorbed by a 3-inch layer of aged, double shreddded hardwood mulch, with nes removed, (when specied) on the surface of the bioltration media. As the water passes through the mulch layer, most of the larger sediment particles and heavy metals are removed through sedimentation and chemical reactions with the organic material in the mulch. Water passes through the bioltration media where the ner particles are removed and numerous chemical reactions take place to immobilize and capture pollutants in the soil media. The cleansed water passes into the underdrain/storage system and remaining ows are directed to a storm sewer system or other appropriate discharge point. Once the pollutants are in the soil, bacteria begin to break down and metabolize the materials and the plants begin to uptake and metabolize the pollutants. Some pollutants such as heavy metals, which are chemically bound to organic particles in the mulch, are released over time as the organic matter decomposes to release the metals to the feeder roots of the plants and the cells of the bacteria in the soil where they remain and are recycled. Other pollutants such as phosphorus are chemically bound to the soil particles and released slowly back to the plants and bacteria and used in their metabolic processes. Nitrogen goes through a variety of very complex biochemical processes where it can ultimately end up in the plant/bacteria biomass, turned to nitrogen gas or dissolves back into the water column as nitrates depending on soil temperature, pH and the availability of oxygen. The pollutants ultimately are retained in the mulch, soil and biomass with some passing out of the system into the air or back into the water. DESIGN AND INSTALLATION Each project presents dierent scopes for the use of FocalPoint® system. To ensure the safe and specied function of this stormwater BMP, Convergent Water Technologies and/or its Value Added Resellers (VAR) review each application before supply. Information and design assistance is available to the design engineer during the planning process. Correct FocalPoint® sizing is essential to optimum performance. The engineer shall submit calculations for approval by the local jurisdiction when required. The contractor and/or VAR is responsible for the correct installation of FocalPoint units as described in approved plans. A comprehensive installation manual is available at www.convergentwater.com. MAINTENANCE Why Maintain? All stormwater treatment systems require maintenance for eective operation. This necessity is often incorporated in your property’s permitting process as a legally binding BMP maintenance agreement. Other reasons for maintenance include: • Avoid legal challenges from your jurisdiction’s maintenance enforcement program. • Prolong the lifespan of your FocalPoint HPMBS. • Avoid costly repairs. • Help reduce pollutant loads leaving your property. Simple maintenance of the FocalPoint® is required to continue eective pollutant removal from stormwater runo before any discharge into downstream waters. This procedure will also extend the longevity of the living bioltration system. The unit will recycle and accumulate pollutants within the biomass, but may also subjected to other materials entering the surface of the system. This may include trash, silt and leaves etc. which will be contained above the mulch and/or bioltration media layer. Too much silt may inhibit the FocalPoint’s® ow rate, which is a primary reason for system maintenance. Removal of accumulated silt/sediment and/or replacement of the mulch layer (when specied), is an important activity that prevents overaccumulation of such silt/sediment. When to Maintain? Convergent Water Technologies and/or its VAR includes a 1-year maintenance plan with each system purchased. Annual included maintenance consists of two (2) scheduled maintenance visits. Additional maintenance may be necessary depending on sediment and trash loading (by Owner or at additional cost). The start of the maintenance plan begins when the system is activated for full operation. Full operation is dened as when the site is appropriately stabilized, the unit is installed and activated (by VAR), i.e., when mulch (if specied) and plantings are added. Activation should be avoided until the site is fully stabilized (full landscaping, grass cover, nal paving and street sweeping completed). Maintenance visits are scheduled seasonally; the spring visit aims to clean up after winter loads including salts and sands. The fall visit helps the system by removing excessive leaf litter. A rst inspection to determine if maintenance is necessary should be performed at least twice annually after storm events of greater than (1) one inch total depth (subject to regional climate). Please refer to the maintenance checklist for specic conditions that indicate if maintenance is necessary. It has been found that in regions which receive between 30-50 inches of annual rainfall, (2) two visits are generally required. Regions with less rainfall often only require (1) one visit per annum. Varying land uses can aect maintenance frequency. Some sites may be subjected to extreme sediment or trash loads, requiring more frequent maintenance visits. This is the reason for detailed notes of maintenance actions per unit, helping the VAR/Maintenance contractor and Owner predict future maintenance frequencies, reecting individual site conditions. Owners must promptly notify the VAR/Maintenance contractor of any damage to the plant(s), which constitute(s) an integral part of the bioltration technology. Owners should also advise other landscape or maintenance contractors to leave all maintenance of the HPMBS to the VAR/Maintenance contractor (i.e. no pruning or fertilizing). EXCLUSION OF SERVICES It is the responsibility of the owner to provide adequate irrigation when necessary to the plant(s) in the FocalPoint® system. Clean up due to major contamination such as oils, chemicals, toxic spills, etc. will result in additional costs and are not covered under the VAR/Maintenance contractor maintenance contract. Should a major contamination event occur, the Owner must block o the outlet pipe of the FocalPoint® (where the cleaned runo drains to, such as drop-inlet) and block o the point where water enters of the FocalPoint®. The VAR/Maintenance contractor should be informed immediately. MAINTENANCE VISIT SUMMARY Each maintenance visit consists of the following simple tasks (detailed instructions below). 1. Inspection of FocalPoint® and surrounding area 2. Removal of debris, trash and mulch 3. Mulch replacement 4. Plant health evaluation (including measurements) and pruning or replacement as necessary 5. Clean area around FocalPoint® 6. Complete paperwork, including date stamped photos of the tasks listed above. MAINTENANCE TOOLS, SAFETY EQUIPMENT AND SUPPLIES Ideal tools include: camera, bucket, shovel, broom, pruners, hoe/rake, and tape measure. Appropriate Personal Protective Equipment (PPE) should be used in accordance with local or company procedures. This may include impervious gloves where the type of trash is unknown, high visibility clothing and barricades when working in close proximity to trac and also safety hats and shoes. MAINTENANCE VISIT PROCEDURE Damage to HPMBS System yes | no to Overow conveyance yes | no Leaves? yes | no Volume of material removed _______ (volume or weight) Health alive | dead Damage to Plant yes | no Inspection of FocalPoint® and surrounding area Record individual unit before maintenance with photograph (numbered). Record on Maintenance Report (see example in this document) the following: Standing Water yes | no Is Bypass Inlet Clear? yes | no Removal of Silt / Sediment / Clay Dig out silt (if any) and mulch and remove trash & foreign items. Silt / Clay Found? yes | no Cups / Bags Found? yes | no Removal of debris, trash and mulch After removal of mulch and debris, measure distance from the top of the FocalPoint® engineered media soil to the ow line elevation of the adjacent overow conveyance. If this distance is greater than that specied on the plans (typ. 6” - 12”), add FocalPoint® media (not top soil or other) to recharge to the distance specied. Distance to media surface to ow line of overow conveyance (inches) ___________ # of Buckets of Media Added ________ Mulch Replacement Most maintenance visits require only replacement mulch (if utilized). Bags of clean, double shredded hardwood mulch are typically used for smaller bioltration beds, however larger systems may require truck loads of mulch. For smaller projects, one cubic foot of mulch will cover four square feet of bioltration bed, and for larger projects, one cubic yard of mulch will cover 108 square feet of bioltration bed. Some visits may require additional FocalPoint® engineered soil media available from the VAR/Contractor. Add double shredded, aged hardwood mulch which has been screened to remove nes, evenly across the entire bioltration media bed to a depth of 3”. Clean accumulated sediment from energy dissipation system at the inlet to the FocalPoint® system to allow for entry of trash during a storm event. Plant health evaluation and pruning or replacement as necessary Examine the plant’s health and replace if dead or dying. Prune as necessary to encourage growth in the correct directions Height above Grate (feet) ______ Width at Widest point (feet) ______ Clean area around FocalPoint® Clean area around unit and remove all refuse to be disposed of appropriately. Complete paperwork Deliver Maintenance Report and photographs as appropriate. Some jurisdictions may require submission of maintenance reports in accordance with approvals. It is the responsibility of the Owner to comply with local regulations. (p) 800.711.5428 | www.convergentwater.com BASIC OPERATIONS FocalPoint® is a modular, high performance bioltration system that often works in tandem with other integrated management practices (IMP). Contaminated stormwater runo enters the bioltration bed through a conveyance swale, planter box, or directly through a curb cut or false inlet. Energy is dissipated by a rock or vegetative dissipation device and is absorbed by a 3-inch layer of aged, double shreddded hardwood mulch, with nes removed, (when specied) on the surface of the bioltration media. As the water passes through the mulch layer, most of the larger sediment particles and heavy metals are removed through sedimentation and chemical reactions with the organic material in the mulch. Water passes through the bioltration media where the ner particles are removed and numerous chemical reactions take place to immobilize and capture pollutants in the soil media. The cleansed water passes into the underdrain/storage system and remaining ows are directed to a storm sewer system or other appropriate discharge point. Once the pollutants are in the soil, bacteria begin to break down and metabolize the materials and the plants begin to uptake and metabolize the pollutants. Some pollutants such as heavy metals, which are chemically bound to organic particles in the mulch, are released over time as the organic matter decomposes to release the metals to the feeder roots of the plants and the cells of the bacteria in the soil where they remain and are recycled. Other pollutants such as phosphorus are chemically bound to the soil particles and released slowly back to the plants and bacteria and used in their metabolic processes. Nitrogen goes through a variety of very complex biochemical processes where it can ultimately end up in the plant/bacteria biomass, turned to nitrogen gas or dissolves back into the water column as nitrates depending on soil temperature, pH and the availability of oxygen. The pollutants ultimately are retained in the mulch, soil and biomass with some passing out of the system into the air or back into the water. DESIGN AND INSTALLATION Each project presents dierent scopes for the use of FocalPoint® system. To ensure the safe and specied function of this stormwater BMP, Convergent Water Technologies and/or its Value Added Resellers (VAR) review each application before supply. Information and design assistance is available to the design engineer during the planning process. Correct FocalPoint® sizing is essential to optimum performance. The engineer shall submit calculations for approval by the local jurisdiction when required. The contractor and/or VAR is responsible for the correct installation of FocalPoint units as described in approved plans. A comprehensive installation manual is available at www.convergentwater.com. MAINTENANCE Why Maintain? All stormwater treatment systems require maintenance for eective operation. This necessity is often incorporated in your property’s permitting process as a legally binding BMP maintenance agreement. Other reasons for maintenance include: • Avoid legal challenges from your jurisdiction’s maintenance enforcement program. • Prolong the lifespan of your FocalPoint HPMBS. • Avoid costly repairs. • Help reduce pollutant loads leaving your property. Simple maintenance of the FocalPoint® is required to continue eective pollutant removal from stormwater runo before any discharge into downstream waters. This procedure will also extend the longevity of the living bioltration system. The unit will recycle and accumulate pollutants within the biomass, but may also subjected to other materials entering the surface of the system. This may include trash, silt and leaves etc. which will be contained above the mulch and/or bioltration media layer. Too much silt may inhibit the FocalPoint’s® ow rate, which is a primary reason for system maintenance. Removal of accumulated silt/sediment and/or replacement of the mulch layer (when specied), is an important activity that prevents overaccumulation of such silt/sediment. When to Maintain? Convergent Water Technologies and/or its VAR includes a 1-year maintenance plan with each system purchased. Annual included maintenance consists of two (2) scheduled maintenance visits. Additional maintenance may be necessary depending on sediment and trash loading (by Owner or at additional cost). The start of the maintenance plan begins when the system is activated for full operation. Full operation is dened as when the site is appropriately stabilized, the unit is installed and activated (by VAR), i.e., when mulch (if specied) and plantings are added. Activation should be avoided until the site is fully stabilized (full landscaping, grass cover, nal paving and street sweeping completed). Maintenance visits are scheduled seasonally; the spring visit aims to clean up after winter loads including salts and sands. The fall visit helps the system by removing excessive leaf litter. A rst inspection to determine if maintenance is necessary should be performed at least twice annually after storm events of greater than (1) one inch total depth (subject to regional climate). Please refer to the maintenance checklist for specic conditions that indicate if maintenance is necessary. It has been found that in regions which receive between 30-50 inches of annual rainfall, (2) two visits are generally required. Regions with less rainfall often only require (1) one visit per annum. Varying land uses can aect maintenance frequency. Some sites may be subjected to extreme sediment or trash loads, requiring more frequent maintenance visits. This is the reason for detailed notes of maintenance actions per unit, helping the VAR/Maintenance contractor and Owner predict future maintenance frequencies, reecting individual site conditions. Owners must promptly notify the VAR/Maintenance contractor of any damage to the plant(s), which constitute(s) an integral part of the bioltration technology. Owners should also advise other landscape or maintenance contractors to leave all maintenance of the HPMBS to the VAR/Maintenance contractor (i.e. no pruning or fertilizing). EXCLUSION OF SERVICES It is the responsibility of the owner to provide adequate irrigation when necessary to the plant(s) in the FocalPoint® system. Clean up due to major contamination such as oils, chemicals, toxic spills, etc. will result in additional costs and are not covered under the VAR/Maintenance contractor maintenance contract. Should a major contamination event occur, the Owner must block o the outlet pipe of the FocalPoint® (where the cleaned runo drains to, such as drop-inlet) and block o the point where water enters of the FocalPoint®. The VAR/Maintenance contractor should be informed immediately. MAINTENANCE VISIT SUMMARY Each maintenance visit consists of the following simple tasks (detailed instructions below). 1. Inspection of FocalPoint® and surrounding area 2. Removal of debris, trash and mulch 3. Mulch replacement 4. Plant health evaluation (including measurements) and pruning or replacement as necessary 5. Clean area around FocalPoint® 6. Complete paperwork, including date stamped photos of the tasks listed above. MAINTENANCE TOOLS, SAFETY EQUIPMENT AND SUPPLIES Ideal tools include: camera, bucket, shovel, broom, pruners, hoe/rake, and tape measure. Appropriate Personal Protective Equipment (PPE) should be used in accordance with local or company procedures. This may include impervious gloves where the type of trash is unknown, high visibility clothing and barricades when working in close proximity to trac and also safety hats and shoes. MAINTENANCE VISIT PROCEDURE Seller warrants goods sold hereunder against defects in materials and workmanship only, for a period of (1) year from date the Seller activates the system into service. Seller makes no other warranties, express or implied. Seller’s liability hereunder shall be conditioned upon the Buyer’s installation, maintenance, and service of the goods in strict compliance with the written instructions and specications provided by the Seller. Any deviation from Seller’s instructions and specications or any abuse or neglect shall void warranties. In the event of any claim upon Seller’s warranty, the burden shall be upon the Buyer to prove strict compliance with all instructions and specications provided by the Seller. Seller’s liability hereunder shall be limited only to the cost or replacement of the goods. Buyer agrees that Seller shall not be liable for any consequential losses arising from the purchase, installation, and/or use of the goods.BIOFILTRATION SYSTEMFocalPoint FocalPoint Warranty (p) 800.711.5428 | www.convergentwater.com Maintenance Checklist Element Problem What To Check Should Exist Action Inlet Mulch Cover Mulch Cover Plants Plants Excessiver sediment or trash accumulation Accumulation of sediment or trash impair free ow of water into FocalPoint Inlet free of obstructions allowing free ow into FocalPoint System Sediments or trash should be removed Ponding of water on mulch cover Ponding in unit could be indicative of clogging due to excessive ne sediment accumulation or spill of petroleum oils Stormwater should drain freely and evenly over mulch cover. Contact VAR for advice. Trash and oatable debris accumulation Excessive trash or debris accumulation. Minimal trash or other debris on mulch cover Trash and debris should be removed and mulch cover raked level. Ensure that bark nugget Plants not growing, or in poor condition Soil/mulch too wet, evidence of spill. Pest infestation. Vandalism to plants. Plants should be healthy and pest free. Contact VAR for advice. Plant growth excessive Plants should be appropriate to the species and location of FocalPoint Trim/prune plants in accordance with typical landscaping and (p) 800.711.5428 | www.convergentwater.com Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Appendix H: Illicit Discharge Compliance Statement Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts Illicit Discharge Compliance Statement The owners of the land/responsible party will be responsible for prohibiting illicit discharges to the stormwater management system during construction and during its life of operation. The stormwater management system is comprised of the components for conveying, treating, and infiltrating stormwater runoff on-site, including stormwater best management practices and any pipes intended to transport stormwater to the groundwater, a surface water, or municipal separate storm sewer system. An illicit discharge shall constitute any connection or discharge to the stormwater management system including, but not limited to, wastewater discharges, discharge of stormwater contaminated by contact with process wastes, raw materials, toxic pollutants, hazardous substances, oil, or grease. Responsible Party*: American Dream Realty c/o Mr. Emanuel Sardinha 16 Harvard Street Westfield, MA 01085 * Upon sale of property or any other transition of ownership, the responsible party shall be reinstated as the new owner or any other group created as determined by the owner. Signature of Responsible Party Representative Date Signature of Representative for Association** Date **Required upon transfer of ownership Proposed Commercial Development Stormwater Drainage Report 55 Damon Road Northampton, Massachusetts R Levesque Associates, Inc. Appendix I: Northampton DPW Inspection Schedule Northampton DPW Inspection Schedule Sign-Off Sheet Inspection Schedule Description Date of Inspection Inspector Passed Failed Notes Initial Inspection Prior to approval of any plan. After site clearing Rough Grading Final Grading Bury Inspection Prior to backfilling of any underground drainage or stormwater conveyance structures. Final Inspection Conducted when all work, inlcuding construction of stormwater management facilities and landscaping have been completed. Final inspection shall include a full, dated TV inspcetion of all stormwater pipes installed. Erosion and Sediment Control Inspections