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Drainage Analysis 10-26-23.pdf 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com STORMWATER DRAINAGE REPORT AND MANAGEMENT PLAN for D.A. Sullivan and Sons Inc. 504 Easthampton Road Northampton, MA Prepared for D.A. Sullivan and Sons, Inc. 82-84 North Street Northampton, Massachusetts Prepared by T Reynolds Engineering 152 Maplewood Terrace Florence, MA 01062 (413) 387-8078 Fax (413) 727-3477 e-mail: terry@treynoldsengineering.com October, 2023 Rev. 10/26/23 T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 2 TABLE OF CONTENTS Project Summary and Site Description ........................................................................................... 3 Soil and Flood Plain Review With Soil Analysis ........................................................................... 3 Method of Drainage Analysis ......................................................................................................... 5 Model Results ................................................................................................................................. 6 Stormwater Management Performance Standards .......................................................................... 7 Construction Period Pollution Prevention and Erosion and Sediment Control Measures .............. 9 Short-Term Erosion Control Maintenance .................................................................................... 11 Post Construction Operation and Maintenance Plan .................................................................... 12 Long Term Pollution Prevention Plan .......................................................................................... 14 FIGURES Figure 1: Locus of Project Area .......................................................................................................4 TABLES Table 1: Rainfall Runoff Results .....................................................................................................6 APPENDICES Appendix A: Pre- & Post-Construction Drainage Area Plans Appendix B: Soils Report Appendix C: Hydrologic Analyses Appendix D: TSS Removal Calculation Worksheet Appendix E: BMPs Checklist T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 3 Project Summary and Site Description D.A. Sullivan and Sons is proposing to construct a 3,680± sf garage located at 504 Easthampton Road in Northampton, MA (see Figure 1). T Reynolds Engineering has been retained by D.A. Sullivan and Sons to design the site and analyze the pre-development and post-development stormwater flow calculations for the proposed project. The purpose of this analysis is to determine the 2, 10, and 100-year peak flow rates and quantities for pre and post conditions. The stormwater management system has been designed to be in general accordance with applicable City of Northampton regulations. The site is currently developed with a single office/warehouse building and associated parking. The site is elevated along the western portion of the property. The site is a mix of impervious and pervious areas due to the paved areas and building. Elevations range from low areas along the east side of 144 to the elevated areas of 158 in the western area. Under existing conditions, runoff from the site runs overland from the west of the site to the eastern perimeters of the property. The majority of runoff from the west south side of the site flows to abutting property. Runoff from remaining areas of the site generally flow to a low point along the eastern perimeter near the northeast corner of the site. The proposed improvements to the site include; the construction of a new 3,680 sf garage building and parking areas. Additional construction includes associated utilities and construction of a stormwater management system. Under the improved conditions, stormwater runoff generated from the building, the parking area and drive through will be collected in a stormwater-management system that will treat and detain up to and including the 100 year storm event. Stormwater entering the stormwater management system will be treated using a water quality swale prior to being infiltrated into a infiltration basin area. The stormwater management system has been designed so that no increases in off-site discharge rates are expected between the pre- and post-development conditions for the 2, 10 and 100-year storm events. Soil and Flood Plain Review With Soil Analysis Review of the Soil Conservation Service (SCS), now Natural Resource Conservation Service (NRCS), Soil Survey of Hampshire County, Central Part, indicates soils located within the project area are identified as 253B Hinckley loamy sand and 260A Sudbury fine sandy. Hinckley soils are typically excessively drained and Sudbury soils are typically moderately well drained, see Appendix C. T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 4 FIGURE 1: LOCUS OF PROJECT AREA (Massmapper) SITE LOCATION T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 5 Method of Drainage Analysis The program HydroCAD was utilized to perform stormwater modeling for this project. HydroCAD uses the NRCS method of analysis TR-20. The TR-20 method is a widely accepted, standard engineering practice within the civil engineering profession. The NRCS method of hydrology analysis utilizes the drainage area, hydraulic length, terrain slope, and soil conditions of a watershed or catchment as input to calculate peak flows and total volume of runoff for specific synthetic rain events. The model analyzes an area approximately 32,130± SF contributing stormwater runoff flows on the project site. TRE modeled the 2-year, 10-year, and 100-year statistical rain events for the existing and proposed condition. The total rainfall per a 24-hour period for the 2, 10, and 100- year statistical rain events are 3.11-inches, 4.99-inches, and 7.99-inches respectively (see Pre and Post Construction Drainage Area Plans, Appendix A). Limitations The stormwater analysis was performed in accordance with standard civil engineering practice and relies on information provided by other parties as well as published information. Potential runoff analysis was limited to areas within the bounds of property owned and areas immediately adjacent and interpreted to drain toward the site of concern. Although the NRCS method has become one of the standard methods of hydrologic analysis within civil engineering community, it may be conservative for use on very small areas of modern development and provide runoff results that are greater than actual conditions. T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 6 Model Results The following table summarizes the results of the drainage analysis using HydroCad (see Appendix C for complete analysis). Four design point were used to evaluate the pre and post construction stormwater flows that leave the site expected for the 2, 10, and 100-year storm events. Table 1: Rainfall Runoff Results Existing and Proposed Peak Discharge DESIGN POINT 2-year (cfs) 10-year (cfs) 100-year (cfs) Pre-Construction Eastern Perimeter 0.36 1.33 3.29 Post- Construction Eastern Perimeter 0.13 1.05 3.20 As can be seen from the above results, stormwater runoff from the 2, 10 and 100-year storm events are not expected to increase the run-off to the adjacent areas from the pre-construction conditions to the post construction condition. There is a no increase for the 100-year event, and as a result is expected not to increase off-site flooding impacts from the 100-year, 24 hour storm (See Hydrologic Analysis, Appendix C). T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 7 Stormwater Management Performance Standards 1. No new Stormwater conveyances (e.g. Outfalls) shall discharge untreated Stormwater directly to or cause erosion in wetlands or Water of the Commonwealth.  There is no increase in runoff rates from the site, and therefore no potential for increased downstream erosion. Discharges have been evaluated to determine that discharge velocities will not result in scouring and erosion (See Hydrologic Analysis, Appendix C).  A stormwater management system has been designed to include a water quality swale. 2. Stormwater Management Facilities must be designed so that post-development Peak Discharge rates do not exceed predevelopment Peak Discharge rates.  Post development peak discharges have been designed to not exceed pre-development peak flows up to and including the 10-year storm event. The project as designed will not increase off-site flooding impacts from the 100-year 24-hour storm (See Hydrologic Analysis, Appendix C). 3. Loss of annual Recharge to Groundwater should be minimized through the use of Infiltration measures to the maximum extent practicable. The annual Recharge from the post-development site should approximate the annual Recharge rate from the predevelopment or existing site conditions, based on soil types.  Stormwater runoff from the impervious areas are directed to a raingarden with an overflow underdrian. Stormwater from the site is calculated to infiltrate at a rate of approximately 0.01 cubic feet per second and exfiltrate 161 cubic feet during a 1-inch storm event (1.22” over 24 hrs). The instantaneous infiltration volume within the basin is approximately 357 cubic feet (volume below the lowest outlet invert). Massachusetts Stormwater Management Standards prescribes that for “A” soil, 0.60-inches of stormwater runoff multiplied by the total impervious area equals the volume of stormwater runoff that should be recharged. The total prescribed recharge volume for type “A” soil is calculated to be 281 cubic feet. See volume sizing calculations, Appendix D. 4. For new development, Stormwater Management Facilities must be designed to remove 80 percent of the average annual load (post development conditions) of total suspended solids (TSS). It is presumed that this standard is met when: a. Suitable nonstructural practices for source control and pollution prevention are implemented; b. Stormwater management Best Management Practices (BMPs) are sized to capture the prescribed Runoff volume; and c. Stormwater management BMPs are maintained as designed.  All newly developed areas have been designed with stormwater BMPs that remove a minimum of 80% TSS. See TSS removal worksheet, Appendix D. 5. Stormwater discharges from areas with higher potential Pollutant loads require the use of specific Stormwater management BMPs (see Stormwater Management Handbook, February 2008, MassDEP, as updated or amended). The use of Infiltration practices without pretreatment is prohibited.  The site does not contain land with higher pollutant loads. T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 8 6. Stormwater discharges to critical areas must utilize certain Stormwater management BMPs approved for critical areas (see Stormwater Management Handbook, February 2008, MassDEP, as updated or amended). Critical areas are outstanding resource waters (ORWs), cold-water fisheries, vernal pools and Recharge areas for public water supplies.  The site is not within a Zone II of a public water supply. 7. Redevelopment of previously developed sites must meet the Stormwater management standards to the maximum extent practicable, as determined by the Board of Public Works. However, if it is not practicable to meet all the standards, Section 4 Performance Standards and Design Requirements Stormwater Management Rules and Regulations 4-2 new (retrofitted or expanded) Stormwater Management Facilities must be designed to improve existing conditions.  The project is not a redevelopment project. 8. Erosion and sediment controls must be implemented to prevent impacts during disturbance and construction activities.  Erosion and sediment controls are incorporated into the project to prevent erosion, control sediments, and stabilize exposed soils during construction (see project Plans and Erosion Control Measures, below). 9. All Stormwater Management Facilities must have an operation and maintenance plan to ensure that systems function as designed. The operation and maintenance plan must be implemented for the life of the system.  The following section describes the long-term stormwater maintenance program to be implemented. 10. All Illicit Discharges to the Stormwater Management Facilities are prohibited.  There are no known illicit discharges to the stormwater management system. T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 9 Construction Period Pollution Prevention and Erosion and Sediment Control Measures The following erosion and sedimentation control measures will be employed during the earthwork and construction phases of the project. 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 engineer 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. Silt Fence: The bottom of the fence shall be trenched into the ground a minimum of 4" and back-filled with compacted soil. Where trenching is not feasible, the 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. 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. 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. Temporary Sediment 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 the 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. 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 (Covered to be kept dry) with 20 Oak stakes Or Silt fence - 30 linear feet. Or Filter Sock - 4, 8 ft. sections (covered to be kept dry) Washed stone - 1 cubic yards, 3/4" to 1 2" diameter T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 10 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 surface runoff from entering the trench. Backfill shall be crowned to allow for settlement and to avoid concentration of runoff on top of the trench. Storm Drain Protection: The storm drain and swale system shall be put into operation as soon as possible in order to control runoff within a non-erodable system. The storm drain system shall be protected against inflow of sediment. Open storm drain structures shall be protected by sediment barriers, “Filtrexx” filter socks, stone filter berms, or filter fabric inserts (tea-bags, silt- sacks or equivalents). These measures shall be maintained until the tributary area is stabilized by paving and vegetative cover. 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. 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. Roadway Sweeping: The entrance to the site and affected portions of the public roadway or paved project roadway shall be swept as needed to control sediment runoff into storm drains or waterways and to control dust migration. T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 11 Short-Term Erosion Control Maintenance  The contractor or subcontractor will be responsible for implementing all erosion and sediment controls.  The on-site contractor will inspect all sediment and erosion controls on a ongoing weekly basis and after each significant rainfall event. Records of the inspections will be prepared and maintained on-site by the contractor.  Sediment shall be removed from behind barriers if greater than 6-inches deep or as needed.  Damaged or deteriorated items will be repaired immediately after identification.  The underside of filter socks should be kept in close contact with the earth and reset or provided with mulch or stone filter as necessary.  The underside of hay bales should be kept in close contact with the earth and reset as necessary.  Sediment that is collected in drainage structures or within sediment controls shall be disposed of properly and, if on site, shall not be placed in an area subject to erosion.  Erosion control structures shall remain in place until all disturbed earth has been securely stabilized. After removal of structures, disturbed areas shall be re-graded and stabilized as necessary. The sedimentation and erosion control plan is included in project plan set. T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 12 Post Construction Operation and Maintenance Plan The following maintenance program is proposed to ensure the continued effectiveness of the structural water quality controls previously described.  The Stormwater management system will be owned and operated by D A Sullivan and Sons, Inc.  Operation and maintenance of stormwater management system will be the responsibility of the Owners.  Inspect and clean as needed all sediment removal devices (i.e. catch basins) four times a year to remove accumulated sand, sediment, and floatable products or as needed based on use.  Water Quality Swale Inspect soil and repair eroded areas monthly. Re-mulch void areas as needed. Remove litter and debris monthly. Treat diseased vegetation as needed. Remove and replace dead vegetation twice per year (spring and fall). Remove invasive species as needed to prevent these species from spreading into the raingarden area.  Infiltration Basin Inspect soil and repair eroded areas monthly. Re-mulch void areas as needed. Remove litter and debris monthly. Treat diseased vegetation as needed. Remove and replace dead vegetation twice per year (spring and fall). Remove invasive species. Upon failure, excavate media area, replace filter stone, soil media and replant. Infiltration Area Maintenance Schedule Areas planted with the Basin and PDQ seed mixes only: YEAR 2: FIRST GROWING SEASON Most sites need maintenance mowing to keep weeds from going to seed and to allow light to penetrate the ground encouraging growth of the majority of the slow-growing natives. You may get some blooms this year, most likely annuals like Black-eyed Susan or Partridge Pea, but you must sacrifice these native flowers if you want the other species to establish. Keep the area cut to 4-6″ this year. Don’t pull the weeds! This will disturb the root systems of the nearby natives trying to establish. YEAR 3: SECOND GROWING SEASON A single mowing cut to a height of 6” in the spring should be expected after which no/little additional mowing is required. Following a full seed set in the fall, a second mowing to cut dead stems and maintain a consistent plant height is optional but not required. Keep in mind that although some species may reach flowering stages in year 3, some could take 4 years or more. YEAR 4 & BEYOND: REGULAR MAINTENANCE An early spring clean-up is recommended to remove leaf litter and overwinter debris such as branches and trash. No other maintenance is generally required during the growing season aside from hand removal of any overly aggressive weeds that emerge. This may T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 13 not be required however depending on species and the season. Following a full seed set in the fall, a second mowing to cut dead stems and maintain a consistent plant height is optional but not required.  Parking Lot Sweeping Paved areas will be swept, at a minimum, two times per year in the months of May and October.  See the Grading and Drainage Plan for a scaled drawing of the treatment train. T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 14 Long Term Pollution Prevention Plan Good Housekeeping Practices The following is a list of good housekeeping practices provided as guidance by DEP to be considered by the property management company hired to maintain the proposed retail building and grounds. Lawn and Garden Activities, including application and disposal of lawn and garden care products, and proper disposal of leaves and yard trimmings. Effective measures include: applying pesticides and fertilizers properly, including: timing; application reduction; providing buffer areas (preferably natural vegetation) between surface waters and lawn and garden activities; limiting lawn watering and landscaping with climate-suitable vegetation; providing guidelines for what to expect from landscaping and lawn care professionals; and providing composting guidelines, if not covered elsewhere under solid waste efforts. <http://www.mass.gov/dep/water/resources/nonpoint.htm#megaman> See “More than Just a Yard: Ecological Landscaping Tools for Massachusetts Homeowners” http://www.mass.gov/envir/mwrc/pdf/More_Than_Just_Yard.pdf and Guide to Lawn and Landscape Water Conservation, http:www.mass.gov/envir/mwrc/pdf/LawnGuide.pdf. Turf Management on golf courses, parks, and recreation areas. Many of the measures described above are applicable to turf management and need to be implemented by caretakers responsible for golf courses and parks and recreation areas (including municipal employees, in some cases). Pet Waste Management. Pooper-scooper laws for pets should be enacted and implemented. Public outreach is essential to the effectiveness of these laws. Priority resource areas, such as bathing beaches and shellfish growing areas may need to exclude pets at least for the summer months or at other critical use times. Specific controls for horses and the control of manure may be needed. <http://www.mass.gov/dep/water/resources/nonpoint.htm#megaman> Integrated Pest Management (IPM) effectively prevents and controls pests (including weeds) in a way that maximizes environmental benefits at a reduced cost to growers. IPM involves applying an array of techniques and control strategies for pest management – with a focus on using them in the proper amounts and determining when they are most needed. By choosing from all possible pest control methods (e.g., biological controls and beneficial organisms) and rotating methods, resistance to repeated chemical controls can be delayed or prevented. <http://www.mass.gov/dep/water/resources/nonpoint.htm#megaman> Proper Storage, Use, and Disposal of Household Hazardous Chemicals, including automobile fluids, pesticides, paints, and solvents. Information should be provided on chemicals of concern, proper use, and disposal options. Household hazardous waste collection days should be sponsored whenever feasible. Recycling programs for used motor oil, antifreeze, and other products should be developed and promoted. T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 15 Storm Drain Stenciling involves labeling storm drain inlets with painted messages warning citizens not to dump pollutants into the drains. The stenciled messages are generally a simple phrase to remind passersby that the storm drains connect to local waterbodies and that dumping pollutes those waters. Some storm drain stencils specify which waterbody the inlet drains to or name the particular river, lake, or bay. Commonly stenciled messages include: “No Dumping. Drains to Water Source,” “Drains to River,” and “You Dump it, You Drink it. No Waste Here.” Pictures can also be used to convey the message, including a shrimp, common game fish, or a graphic depiction of the path from drain to waterbody. Communities with a large Spanish- speaking population might wish to develop stencils in both English and Spanish, or use a graphic alone. <http://www.mass.gov/dep/water/resources/nonpoint.htm#megaman> Proper Operation and Maintenance of Septic Systems. Knowledge of proper operation and maintenance of septic systems should be promoted to avoid serious failures. Car Washing. This management measure involves educating the general public, businesses, municipal fleets (public works, school buses, fire, police, and parks) on the water quality impacts of the outdoor washing of automobiles and how to avoid allowing polluted runoff to enter the storm drain system. Outdoor car washing has the potential to result in high loads of nutrients, metals, and hydrocarbons during dry weather conditions in many watersheds, as the detergent- rich water used to wash the grime off our cars flows down streets and into storm drains. Commercial car wash facilities often recycle their water or are required to treat their wash-water discharge prior to release to the sanitary sewer system. As a result, most stormwater impacts from car washing are from residents, businesses, and charity car wash fundraisers that discharge polluted wash water to the storm drain system. <http://www.mass.gov/dep/water/resources/nonpoint.htm#megaman> Commercial Operations and Activities, including parking lots, gas stations, and other local businesses. Recycling, spill prevention and response plans, and proper material storage and disposal should be promoted. Using dry floor cleaners and absorbent materials and limiting the use of water to clean driveways and walkways should be encouraged. Care should be taken to avoid accidental disposal of hazardous materials down floor drains. Floor drains should be inventoried. Department of Public Works Facilities (DPWs). Because of the nature of the activities they perform, such as storing and managing sand, salt, and chemicals, and fueling and maintaining trucks and other equipment, DPWs are in a unique position to prevent a wide range of compounds from becoming stormwater pollutants. MassDEP has developed a Fact Sheet specifically for DPWs: <http://www.mass.gov/dep/water/resources/nonpoint.htm#megaman> Other efforts, including water conservation and litter control, can be tied to nonpoint source pollution control. Provisions for Storing Materials and Waste Products Inside or Under Cover All maintenance will be conducted by independent contractors hired by the property owner. No maintenance equipment or materials will be kept on-site. T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 16 Vehicle Washing Controls All maintenance vehicles will be associated with independent contractors hired by the property manager. These vehicles will not be cleaned on-site. Vehicles owned by employees will not be cleaned on-site. Requirements for Routine inspections and Maintenance of Stormwater BMP’s Routine inspections will be performed to ensure the correct functioning of stormwater BMP’s. Please see the Long Term Stormwater Maintenance Program for detail regarding inspections and maintenance. Spill Prevention and Response Plan It will be the responsibility of the property manager to contain and legally remove any materials that are spilled onsite. The property manager will be responsible for providing an emergency response plan for any spills within the subject property. Provisions for Maintenance of Lawns, Gardens, and Other Landscaped Areas There will be standard landscaping consistent with other industrial uses. The use of fertilizers, herbicides and pesticides will be limited to areas outside of resource areas, and outside of the 50- foot buffer of the Bordering Vegetated Wetland (BVW) on-site. Standard practices will be conducted outside of said areas and will be the ultimate responsibility of the property manager. Requirements for Storage and Use of Fertilizers, Herbicides, and Pesticides As mentioned above, fertilizers, herbicides, and pesticides will be limited to those areas outside of the resource area and the 50-foot buffer zone to the bordering vegetated wetland on-site. All of these materials will be stored off-site by the independent contractor hired by the property manager and will be applied consistent with industry standards and applicable laws. Pet Waste Management Provisions Pet waste is not anticipated to be a problem. However, any pet waste is required to be properly maintained by the pet owner. Provisions for Operation and Management of Septic Systems There are no septic systems on-site. City sewer will be utilized for the proposed building. Provisions for Solid Waste Management A dumpster pad will be located on-site at the rear of the parking area. This area will be enclosed with PVC fencing to obscure it from plain view. The traffic circulation within the parking area is two-way throughout, which should provide easy access for trash removal. Snow Disposal and Plowing Plans Relative to Wetland Resource Areas All snow removal and deicing activities will be conducted as spelled out in the snow removal plan provided herewith. A snow removal area is proposed along the north side of the parking area. Snow will be stored in this area in the event of winter storms. T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com 17 Winter Road Salt and/or Sand Use and Storage Restrictions The use of road salt will be kept to a minimum per the Department of Environmental Protection’s (DEP’s) standards. Please refer to the Long Term Stormwater Maintenance Program for additional information. Parking Lot Sweeping Schedules Please see the Long-Term Stormwater Maintenance Program. Provisions for Prevention of Illicit Discharges to the Stormwater Management System Any and all illicit discharges to the stormwater basin will be promptly dealt with. It will be the property manager’s responsibility to ensure compliance with the legal disposal of all materials and containment/cleanup of any illicit discharges. Training for Staff or Personnel Involved with Implementing Long-Term Pollution Prevention Plan The property manager on-site will be responsible for the implementations of the measures set forth in the Long-Term Pollution Prevention Plan (LTPPP). Said property manager will be responsible for providing documentation that management staff and sub-contractors involved with the implementation of the LTPPP have been trained to conduct such tasks. T Reynolds Engineering TopatoCo Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com Appendix A: Pre-Construction and Post-Construction Drainage Area Plans Civil EngineersPlanning, Design, and Permitting Services ph: 413 387-8078 fax: 413 727-3477 email: terry@treynoldsengineering.com www.treynoldsengineering.com 152 Maplewood TerraceFlorence, MA 01062 T Reynolds Engineering DATE: PREPARED FOR: ISSUE DATE: SCALE: OF REVISIONS: UNAUTHORIZED ALTERATION OFTHIS DOCUMENT IS A VIOLATION OFMASSACHUSETTS STATE LAW SHEET NO. PROJECT NO: DRAWING:Existing Drainage Areas PlanD.A. Sullivan Garage504 Easthampton RoadNorthampton, MAD. A. Sullivan & Sons, Inc. 82-84 North Street Northampton, MA 01060 10/9/23 21 1" = 20' Eng Plan 23-0705 NOT FOR CONSTRUCTION 147146 145146146146146147146 147Civil EngineersPlanning, Design, and Permitting Services ph: 413 387-8078 fax: 413 727-3477 email: terry@treynoldsengineering.com www.treynoldsengineering.com 152 Maplewood TerraceFlorence, MA 01062 T Reynolds Engineering DATE: PREPARED FOR: SCALE: OF REVISIONS: UNAUTHORIZED ALTERATION OFTHIS DOCUMENT IS A VIOLATION OFMASSACHUSETTS STATE LAW SHEET NO. PROJECT NO: DRAWING:Proposed Drainage Area PlanD.A. Sullivan Garage504 Easthampton RoadNorthampton, MAD. A. Sullivan & Sons, Inc. 82-84 North Street Northampton, MA 01060 2 1" = 20' Eng Plan 23-0705 NOT FOR CONSTRUCTION 2 ISSUE DATE:10/9/23 T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com Appendix B: Soils Report DEP Form 11 Soil Suitability Assessment for On-Site Sewage Disposal • Page 1 of 1 Commonwealth of Massachusetts City/Town of Form 11 - Soil Suitability Assessment for On-Site Sewage Disposal Date:10/23/23 504 Easthampton Road, Northampton Deep Observation Hole Number:1 Depth (In.) Soil Horizon/ Layer Soil Matrix: Color-Moist (Munsell) Redoximorphic Features (mottles) Soil Texture (USDA) Coarse Fragments % by Volume Soil Structure Soil Consistence (Moist) Other Depth Color Percent Gravel Cobbles & Stones TP-1 0-10 A 10YR4/6 L GR FR 10-16 B 10YR4/4 LS SBK FR 16-36 C 10YR4/4 20 10YR5/8 C S SG FR Additional Notes TP-1 WEEPING @ 30" 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 October 8, 2023 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 (https://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 2 alternative means 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..................................................................................................................8 Soil Map................................................................................................................9 Legend................................................................................................................10 Map Unit Legend................................................................................................12 Map Unit Descriptions........................................................................................12 Hampshire County, Massachusetts, Central Part...........................................14 253B—Hinckley loamy sand, 3 to 8 percent slopes....................................14 260A—Sudbury fine sandy loam, 0 to 3 percent slopes.............................15 727A—Enosburg fine sandy loam, 0 to 3 percent slopes...........................17 References............................................................................................................19 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 5 scientists classified and named the soils in the survey area, they compared the 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 Custom Soil Resource Report 6 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 7 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. 8 9 Custom Soil Resource Report Soil Map 46848804684890468490046849104684920468493046849404684950468496046849704684880468489046849004684910468492046849304684940468495046849604684970693050 693060 693070 693080 693090 693100 693110 693120 693130 693140 693150 693160 693170 693180 693190 693200 693050 693060 693070 693080 693090 693100 693110 693120 693130 693140 693150 693160 693170 693180 693190 693200 42° 17' 35'' N 72° 39' 29'' W42° 17' 35'' N72° 39' 23'' W42° 17' 31'' N 72° 39' 29'' W42° 17' 31'' N 72° 39' 23'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 30 60 120 180Feet 0 10 20 40 60Meters Map Scale: 1:711 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. 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: 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 18, Sep 10, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Oct 15, 2020—Oct 31, 2020 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background Custom Soil Resource Report 10 MAP LEGEND MAP INFORMATION imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 11 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 253B Hinckley loamy sand, 3 to 8 percent slopes 1.3 64.6% 260A Sudbury fine sandy loam, 0 to 3 percent slopes 0.5 23.1% 727A Enosburg fine sandy loam, 0 to 3 percent slopes 0.3 12.3% Totals for Area of Interest 2.1 100.0% 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 Custom Soil Resource Report 12 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. 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 13 Hampshire County, Massachusetts, Central Part 253B—Hinckley loamy sand, 3 to 8 percent slopes Map Unit Setting National map unit symbol: 2svm8 Elevation: 0 to 1,430 feet Mean annual precipitation: 36 to 53 inches Mean annual air temperature: 39 to 55 degrees F Frost-free period: 140 to 250 days Farmland classification: Farmland of statewide importance Map Unit Composition Hinckley and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Hinckley Setting Landform:Outwash deltas, outwash terraces, kames, kame terraces, moraines, eskers, outwash plains Landform position (two-dimensional):Summit, shoulder, backslope, footslope Landform position (three-dimensional):Nose slope, side slope, base slope, crest, riser, tread Down-slope shape:Concave, convex, linear Across-slope shape:Convex, linear, concave Parent material:Sandy and gravelly glaciofluvial deposits derived from gneiss and/or granite and/or schist Typical profile Oe - 0 to 1 inches: moderately decomposed plant material A - 1 to 8 inches: loamy sand Bw1 - 8 to 11 inches: gravelly loamy sand Bw2 - 11 to 16 inches: gravelly loamy sand BC - 16 to 19 inches: very gravelly loamy sand C - 19 to 65 inches: very gravelly sand Properties and qualities Slope:3 to 8 percent Depth to restrictive feature:More than 80 inches Drainage class:Excessively drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat):Moderately high to very high (1.42 to 99.90 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Maximum salinity:Nonsaline (0.0 to 1.9 mmhos/cm) Available water supply, 0 to 60 inches: Very low (about 3.0 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3s Hydrologic Soil Group: A Custom Soil Resource Report 14 Ecological site: F144AY022MA - Dry Outwash Hydric soil rating: No Minor Components Windsor Percent of map unit:8 percent Landform:Outwash deltas, outwash terraces, moraines, eskers, kames, outwash plains, kame terraces Landform position (two-dimensional):Summit, shoulder, backslope, footslope Landform position (three-dimensional):Nose slope, side slope, base slope, crest, riser, tread Down-slope shape:Concave, convex, linear Across-slope shape:Convex, linear, concave Hydric soil rating: No Sudbury Percent of map unit:5 percent Landform:Outwash deltas, outwash terraces, moraines, outwash plains, kame terraces Landform position (two-dimensional):Backslope, footslope Landform position (three-dimensional):Head slope, side slope, base slope, tread Down-slope shape:Concave, linear Across-slope shape:Concave, linear Hydric soil rating: No Agawam Percent of map unit:2 percent Landform:Outwash deltas, outwash terraces, moraines, eskers, kames, outwash plains, kame terraces Landform position (two-dimensional):Summit, shoulder, backslope, footslope Landform position (three-dimensional):Nose slope, side slope, base slope, crest, riser, tread Down-slope shape:Concave, convex, linear Across-slope shape:Convex, linear, concave Hydric soil rating: No 260A—Sudbury fine sandy loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 9b1z Elevation: 0 to 2,100 feet Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: All areas are prime farmland Map Unit Composition Sudbury and similar soils:85 percent Minor components:15 percent Custom Soil Resource Report 15 Estimates are based on observations, descriptions, and transects of the mapunit. Description of Sudbury Setting Landform:Outwash plains Landform position (two-dimensional):Footslope Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Concave Parent material:Friable loamy eolian deposits over loose sandy glaciofluvial deposits Typical profile H1 - 0 to 10 inches: fine sandy loam H2 - 10 to 16 inches: fine sandy loam H3 - 16 to 28 inches: gravelly loamy sand H4 - 28 to 60 inches: stratified gravelly sand to very gravelly loamy sand Properties and qualities Slope:0 to 3 percent Depth to restrictive feature:More than 80 inches Drainage class:Moderately well drained Runoff class: Very low Capacity of the most limiting layer to transmit water (Ksat):High (2.00 to 6.00 in/hr) Depth to water table:About 18 to 36 inches Frequency of flooding:None Frequency of ponding:None Available water supply, 0 to 60 inches: Low (about 4.8 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: B Ecological site: F144AY027MA - Moist Sandy Outwash Hydric soil rating: No Minor Components Merrimac Percent of map unit:5 percent Hydric soil rating: No Hinckley Percent of map unit:5 percent Hydric soil rating: No Walpole Percent of map unit:5 percent Landform:Terraces Hydric soil rating: Yes Custom Soil Resource Report 16 727A—Enosburg fine sandy loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 99zr Elevation: 90 to 1,000 feet Mean annual precipitation: 40 to 50 inches Mean annual air temperature: 45 to 52 degrees F Frost-free period: 140 to 240 days Farmland classification: Not prime farmland Map Unit Composition Enosburg and similar soils:80 percent Minor components:20 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Enosburg Setting Landform:Terraces Landform position (three-dimensional):Tread Down-slope shape:Linear Across-slope shape:Linear Parent material:Loose sandy glaciofluvial deposits over silty glaciolacustrine deposits Typical profile H1 - 0 to 9 inches: fine sandy loam H2 - 9 to 25 inches: loamy sand H3 - 25 to 60 inches: stratified loamy sand to silty clay Properties and qualities Slope:0 to 3 percent Depth to restrictive feature:More than 80 inches Drainage class:Poorly drained Runoff class: Very high 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 0 to 12 inches Frequency of flooding:None Frequency of ponding:None Available water supply, 0 to 60 inches: Moderate (about 8.2 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3w Hydrologic Soil Group: C/D Ecological site: F144AY028MA - Wet Outwash Hydric soil rating: Yes Custom Soil Resource Report 17 Minor Components Maybid Percent of map unit:10 percent Landform:Depressions Hydric soil rating: Yes Amostown Percent of map unit:5 percent Hydric soil rating: No Raynham Percent of map unit:5 percent Landform:Depressions Hydric soil rating: Yes Custom Soil Resource Report 18 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 19 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 20 T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com Appendix C: Hydrologic Analyses 1S 5R Wetland Routing Diagram for Pre DevPrepared by T Reynolds Engineering, Printed 10/12/2023 HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link Pre Dev Printed 10/12/2023Prepared by T Reynolds Engineering Page 2HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (sq-ft) CN Description (subcatchment-numbers) 15,299 39 >75% Grass cover, Good, HSG A (1S) 3,720 61 >75% Grass cover, Good, HSG B (1S) 1,979 96 Gravel surface, HSG A (1S) 7,334 98 Paved parking, HSG A (1S) 3,798 98 Roofs, HSG A (1S) 32,130 65 TOTAL AREA Type III 24-hr 2-Year Event Rainfall=3.11"Pre Dev Printed 10/12/2023Prepared by T Reynolds Engineering Page 3HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=32,130 sf 34.65% Impervious Runoff Depth>0.49"Subcatchment 1S: Tc=6.0 min CN=65 Runoff=0.36 cfs 1,323 cf Inflow=0.36 cfs 1,323 cfReach 5R: Wetland Outflow=0.36 cfs 1,323 cf Total Runoff Area = 32,130 sf Runoff Volume = 1,323 cf Average Runoff Depth = 0.49" 65.35% Pervious = 20,998 sf 34.65% Impervious = 11,132 sf Type III 24-hr 2-Year Event Rainfall=3.11"Pre Dev Printed 10/12/2023Prepared by T Reynolds Engineering Page 4HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Runoff = 0.36 cfs @ 12.11 hrs, Volume= 1,323 cf, Depth> 0.49" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Event Rainfall=3.11" Area (sf) CN Description 3,798 98 Roofs, HSG A 7,334 98 Paved parking, HSG A 1,979 96 Gravel surface, HSG A 15,299 39 >75% Grass cover, Good, HSG A 3,720 61 >75% Grass cover, Good, HSG B 32,130 65 Weighted Average 20,998 65.35% Pervious Area 11,132 34.65% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Reach 5R: Wetland Inflow Area = 32,130 sf, 34.65% Impervious, Inflow Depth > 0.49" for 2-Year Event event Inflow = 0.36 cfs @ 12.11 hrs, Volume= 1,323 cf Outflow = 0.36 cfs @ 12.11 hrs, Volume= 1,323 cf, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Event Rainfall=4.99"Pre Dev Printed 10/12/2023Prepared by T Reynolds Engineering Page 5HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=32,130 sf 34.65% Impervious Runoff Depth>1.50"Subcatchment 1S: Tc=6.0 min CN=65 Runoff=1.33 cfs 4,025 cf Inflow=1.33 cfs 4,025 cfReach 5R: Wetland Outflow=1.33 cfs 4,025 cf Total Runoff Area = 32,130 sf Runoff Volume = 4,025 cf Average Runoff Depth = 1.50" 65.35% Pervious = 20,998 sf 34.65% Impervious = 11,132 sf Type III 24-hr 10-Year Event Rainfall=4.99"Pre Dev Printed 10/12/2023Prepared by T Reynolds Engineering Page 6HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Runoff = 1.33 cfs @ 12.10 hrs, Volume= 4,025 cf, Depth> 1.50" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Event Rainfall=4.99" Area (sf) CN Description 3,798 98 Roofs, HSG A 7,334 98 Paved parking, HSG A 1,979 96 Gravel surface, HSG A 15,299 39 >75% Grass cover, Good, HSG A 3,720 61 >75% Grass cover, Good, HSG B 32,130 65 Weighted Average 20,998 65.35% Pervious Area 11,132 34.65% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Reach 5R: Wetland Inflow Area = 32,130 sf, 34.65% Impervious, Inflow Depth > 1.50" for 10-Year Event event Inflow = 1.33 cfs @ 12.10 hrs, Volume= 4,025 cf Outflow = 1.33 cfs @ 12.10 hrs, Volume= 4,025 cf, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Event Rainfall=7.99"Pre Dev Printed 10/12/2023Prepared by T Reynolds Engineering Page 7HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=32,130 sf 34.65% Impervious Runoff Depth>3.60"Subcatchment 1S: Tc=6.0 min CN=65 Runoff=3.29 cfs 9,652 cf Inflow=3.29 cfs 9,652 cfReach 5R: Wetland Outflow=3.29 cfs 9,652 cf Total Runoff Area = 32,130 sf Runoff Volume = 9,652 cf Average Runoff Depth = 3.60" 65.35% Pervious = 20,998 sf 34.65% Impervious = 11,132 sf Type III 24-hr 100-Year Event Rainfall=7.99"Pre Dev Printed 10/12/2023Prepared by T Reynolds Engineering Page 8HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Runoff = 3.29 cfs @ 12.09 hrs, Volume= 9,652 cf, Depth> 3.60" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Event Rainfall=7.99" Area (sf) CN Description 3,798 98 Roofs, HSG A 7,334 98 Paved parking, HSG A 1,979 96 Gravel surface, HSG A 15,299 39 >75% Grass cover, Good, HSG A 3,720 61 >75% Grass cover, Good, HSG B 32,130 65 Weighted Average 20,998 65.35% Pervious Area 11,132 34.65% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Reach 5R: Wetland Inflow Area = 32,130 sf, 34.65% Impervious, Inflow Depth > 3.60" for 100-Year Event event Inflow = 3.29 cfs @ 12.09 hrs, Volume= 9,652 cf Outflow = 3.29 cfs @ 12.09 hrs, Volume= 9,652 cf, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs 1S 2S 3R Wetland 1P Rain Garden 1 Routing Diagram for Post Dev 10-25-23Prepared by T Reynolds Engineering, Printed 10/26/2023 HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Subcat Reach Pond Link Post Dev 10-25-23 Printed 10/26/2023Prepared by T Reynolds Engineering Page 2HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (sq-ft) CN Description (subcatchment-numbers) 12,699 39 >75% Grass cover, Good, HSG A (1S, 2S) 2,340 61 >75% Grass cover, Good, HSG B (1S, 2S) 9,254 98 Paved parking, HSG A (1S) 7,044 98 Roofs, HSG A (1S) 793 98 Water Surface, HSG A (1S) 32,130 72 TOTAL AREA Type III 24-hr 2-Year Event Rainfall=3.11"Post Dev 10-25-23 Printed 10/26/2023Prepared by T Reynolds Engineering Page 3HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Time span=5.00-72.00 hrs, dt=0.05 hrs, 1341 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=29,150 sf 58.63% Impervious Runoff Depth=0.98"Subcatchment 1S: Tc=6.0 min CN=74 Runoff=0.71 cfs 2,378 cf Runoff Area=2,980 sf 0.00% Impervious Runoff Depth=0.08"Subcatchment 2S: Tc=6.0 min CN=48 Runoff=0.00 cfs 19 cf Inflow=0.13 cfs 211 cfReach 3R: Wetland Outflow=0.13 cfs 211 cf Peak Elev=145.66' Storage=515 cf Inflow=0.71 cfs 2,378 cfPond 1P: Rain Garden 1 Discarded=0.15 cfs 2,186 cf Secondary=0.13 cfs 192 cf Outflow=0.28 cfs 2,378 cf Total Runoff Area = 32,130 sf Runoff Volume = 2,396 cf Average Runoff Depth = 0.89" 46.81% Pervious = 15,039 sf 53.19% Impervious = 17,091 sf Type III 24-hr 2-Year Event Rainfall=3.11"Post Dev 10-25-23 Printed 10/26/2023Prepared by T Reynolds Engineering Page 4HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Runoff = 0.71 cfs @ 12.10 hrs, Volume= 2,378 cf, Depth= 0.98" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Event Rainfall=3.11" Area (sf) CN Description 9,254 98 Paved parking, HSG A 7,044 98 Roofs, HSG A 793 98 Water Surface, HSG A 11,000 39 >75% Grass cover, Good, HSG A 1,059 61 >75% Grass cover, Good, HSG B 29,150 74 Weighted Average 12,059 41.37% Pervious Area 17,091 58.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2S: Runoff = 0.00 cfs @ 14.72 hrs, Volume=19 cf, Depth= 0.08" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Event Rainfall=3.11" Area (sf) CN Description 1,699 39 >75% Grass cover, Good, HSG A 1,281 61 >75% Grass cover, Good, HSG B 2,980 48 Weighted Average 2,980 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Reach 3R: Wetland Inflow Area = 2,980 sf, 0.00% Impervious, Inflow Depth = 0.85" for 2-Year Event event Inflow = 0.13 cfs @ 12.41 hrs, Volume=211 cf Outflow = 0.13 cfs @ 12.41 hrs, Volume=211 cf, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Event Rainfall=3.11"Post Dev 10-25-23 Printed 10/26/2023Prepared by T Reynolds Engineering Page 5HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Summary for Pond 1P: Rain Garden 1 Inflow Area = 29,150 sf, 58.63% Impervious, Inflow Depth = 0.98" for 2-Year Event event Inflow = 0.71 cfs @ 12.10 hrs, Volume= 2,378 cf Outflow = 0.28 cfs @ 12.41 hrs, Volume= 2,378 cf, Atten= 60%, Lag= 18.7 min Discarded = 0.15 cfs @ 12.41 hrs, Volume= 2,186 cf Secondary = 0.13 cfs @ 12.41 hrs, Volume=192 cf Routing by Stor-Ind method, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 145.66' @ 12.41 hrs Surf.Area= 2,435 sf Storage= 515 cf Plug-Flow detention time= 21.4 min calculated for 2,376 cf (100% of inflow) Center-of-Mass det. time= 21.4 min ( 885.3 - 863.9 ) Volume Invert Avail.Storage Storage Description #1 145.40' 1,547 cf Custom Stage Data (Prismatic) Listed below (Recalc) x 2 Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft) (cubic-feet) (cubic-feet) 145.40 793 0 0 146.00 1,786 774 774 Device Routing Invert Outlet Devices #1 Discarded 145.40'2.410 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 143.50' #2 Secondary 145.60'4.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 Discarded OutFlow Max=0.15 cfs @ 12.41 hrs HW=145.66' (Free Discharge) 1=Exfiltration ( Controls 0.15 cfs) Secondary OutFlow Max=0.13 cfs @ 12.41 hrs HW=145.66' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 0.13 cfs @ 0.58 fps) Type III 24-hr 10-Year Event Rainfall=4.99"Post Dev 10-25-23 Printed 10/26/2023Prepared by T Reynolds Engineering Page 6HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Time span=5.00-72.00 hrs, dt=0.05 hrs, 1341 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=29,150 sf 58.63% Impervious Runoff Depth=2.36"Subcatchment 1S: Tc=6.0 min CN=74 Runoff=1.81 cfs 5,724 cf Runoff Area=2,980 sf 0.00% Impervious Runoff Depth=0.58"Subcatchment 2S: Tc=6.0 min CN=48 Runoff=0.02 cfs 145 cf Inflow=1.05 cfs 2,058 cfReach 3R: Wetland Outflow=1.05 cfs 2,058 cf Peak Elev=145.82' Storage=965 cf Inflow=1.81 cfs 5,724 cfPond 1P: Rain Garden 1 Discarded=0.19 cfs 3,811 cf Secondary=1.03 cfs 1,913 cf Outflow=1.22 cfs 5,724 cf Total Runoff Area = 32,130 sf Runoff Volume = 5,869 cf Average Runoff Depth = 2.19" 46.81% Pervious = 15,039 sf 53.19% Impervious = 17,091 sf Type III 24-hr 10-Year Event Rainfall=4.99"Post Dev 10-25-23 Printed 10/26/2023Prepared by T Reynolds Engineering Page 7HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Runoff = 1.81 cfs @ 12.09 hrs, Volume= 5,724 cf, Depth= 2.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Event Rainfall=4.99" Area (sf) CN Description 9,254 98 Paved parking, HSG A 7,044 98 Roofs, HSG A 793 98 Water Surface, HSG A 11,000 39 >75% Grass cover, Good, HSG A 1,059 61 >75% Grass cover, Good, HSG B 29,150 74 Weighted Average 12,059 41.37% Pervious Area 17,091 58.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2S: Runoff = 0.02 cfs @ 12.15 hrs, Volume=145 cf, Depth= 0.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Event Rainfall=4.99" Area (sf) CN Description 1,699 39 >75% Grass cover, Good, HSG A 1,281 61 >75% Grass cover, Good, HSG B 2,980 48 Weighted Average 2,980 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Reach 3R: Wetland Inflow Area = 2,980 sf, 0.00% Impervious, Inflow Depth = 8.29" for 10-Year Event event Inflow = 1.05 cfs @ 12.20 hrs, Volume= 2,058 cf Outflow = 1.05 cfs @ 12.20 hrs, Volume= 2,058 cf, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Event Rainfall=4.99"Post Dev 10-25-23 Printed 10/26/2023Prepared by T Reynolds Engineering Page 8HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Summary for Pond 1P: Rain Garden 1 Inflow Area = 29,150 sf, 58.63% Impervious, Inflow Depth = 2.36" for 10-Year Event event Inflow = 1.81 cfs @ 12.09 hrs, Volume= 5,724 cf Outflow = 1.22 cfs @ 12.20 hrs, Volume= 5,724 cf, Atten= 32%, Lag= 6.1 min Discarded = 0.19 cfs @ 12.20 hrs, Volume= 3,811 cf Secondary = 1.03 cfs @ 12.20 hrs, Volume= 1,913 cf Routing by Stor-Ind method, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 145.82' @ 12.20 hrs Surf.Area= 2,984 sf Storage= 965 cf Plug-Flow detention time= 20.8 min calculated for 5,720 cf (100% of inflow) Center-of-Mass det. time= 20.8 min ( 858.3 - 837.5 ) Volume Invert Avail.Storage Storage Description #1 145.40' 1,547 cf Custom Stage Data (Prismatic) Listed below (Recalc) x 2 Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft) (cubic-feet) (cubic-feet) 145.40 793 0 0 146.00 1,786 774 774 Device Routing Invert Outlet Devices #1 Discarded 145.40'2.410 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 143.50' #2 Secondary 145.60'4.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 Discarded OutFlow Max=0.19 cfs @ 12.20 hrs HW=145.82' (Free Discharge) 1=Exfiltration ( Controls 0.19 cfs) Secondary OutFlow Max=1.03 cfs @ 12.20 hrs HW=145.82' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 1.03 cfs @ 1.16 fps) Type III 24-hr 100-Year Event Rainfall=7.99"Post Dev 10-25-23 Printed 10/26/2023Prepared by T Reynolds Engineering Page 9HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Time span=5.00-72.00 hrs, dt=0.05 hrs, 1341 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind method - Pond routing by Stor-Ind method Runoff Area=29,150 sf 58.63% Impervious Runoff Depth=4.92"Subcatchment 1S: Tc=6.0 min CN=74 Runoff=3.77 cfs 11,944 cf Runoff Area=2,980 sf 0.00% Impervious Runoff Depth=2.04"Subcatchment 2S: Tc=6.0 min CN=48 Runoff=0.14 cfs 506 cf Inflow=3.20 cfs 6,589 cfReach 3R: Wetland Outflow=3.20 cfs 6,589 cf Peak Elev=146.04' Storage=1,547 cf Inflow=3.77 cfs 11,944 cfPond 1P: Rain Garden 1 Discarded=0.25 cfs 5,860 cf Secondary=3.08 cfs 6,084 cf Outflow=3.33 cfs 11,944 cf Total Runoff Area = 32,130 sf Runoff Volume = 12,449 cf Average Runoff Depth = 4.65" 46.81% Pervious = 15,039 sf 53.19% Impervious = 17,091 sf Type III 24-hr 100-Year Event Rainfall=7.99"Post Dev 10-25-23 Printed 10/26/2023Prepared by T Reynolds Engineering Page 10HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: Runoff = 3.77 cfs @ 12.09 hrs, Volume= 11,944 cf, Depth= 4.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Event Rainfall=7.99" Area (sf) CN Description 9,254 98 Paved parking, HSG A 7,044 98 Roofs, HSG A 793 98 Water Surface, HSG A 11,000 39 >75% Grass cover, Good, HSG A 1,059 61 >75% Grass cover, Good, HSG B 29,150 74 Weighted Average 12,059 41.37% Pervious Area 17,091 58.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment 2S: Runoff = 0.14 cfs @ 12.10 hrs, Volume=506 cf, Depth= 2.04" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Event Rainfall=7.99" Area (sf) CN Description 1,699 39 >75% Grass cover, Good, HSG A 1,281 61 >75% Grass cover, Good, HSG B 2,980 48 Weighted Average 2,980 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Reach 3R: Wetland Inflow Area = 2,980 sf, 0.00% Impervious, Inflow Depth = 26.53" for 100-Year Event event Inflow = 3.20 cfs @ 12.15 hrs, Volume= 6,589 cf Outflow = 3.20 cfs @ 12.15 hrs, Volume= 6,589 cf, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind method, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 100-Year Event Rainfall=7.99"Post Dev 10-25-23 Printed 10/26/2023Prepared by T Reynolds Engineering Page 11HydroCAD® 10.00-25 s/n 04155 © 2019 HydroCAD Software Solutions LLC Summary for Pond 1P: Rain Garden 1 Inflow Area = 29,150 sf, 58.63% Impervious, Inflow Depth = 4.92" for 100-Year Event event Inflow = 3.77 cfs @ 12.09 hrs, Volume= 11,944 cf Outflow = 3.33 cfs @ 12.15 hrs, Volume= 11,944 cf, Atten= 12%, Lag= 3.6 min Discarded = 0.25 cfs @ 12.15 hrs, Volume= 5,860 cf Secondary = 3.08 cfs @ 12.15 hrs, Volume= 6,084 cf Routing by Stor-Ind method, Time Span= 5.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 146.04' @ 12.15 hrs Surf.Area= 3,572 sf Storage= 1,547 cf Plug-Flow detention time= 18.8 min calculated for 11,935 cf (100% of inflow) Center-of-Mass det. time= 18.8 min ( 835.2 - 816.4 ) Volume Invert Avail.Storage Storage Description #1 145.40' 1,547 cf Custom Stage Data (Prismatic) Listed below (Recalc) x 2 Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft) (cubic-feet) (cubic-feet) 145.40 793 0 0 146.00 1,786 774 774 Device Routing Invert Outlet Devices #1 Discarded 145.40'2.410 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 143.50' #2 Secondary 145.60'4.0' long x 3.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 Coef. (English) 2.44 2.58 2.68 2.67 2.65 2.64 2.64 2.68 2.68 2.72 2.81 2.92 2.97 3.07 3.32 Discarded OutFlow Max=0.25 cfs @ 12.15 hrs HW=146.04' (Free Discharge) 1=Exfiltration ( Controls 0.25 cfs) Secondary OutFlow Max=3.07 cfs @ 12.15 hrs HW=146.04' (Free Discharge) 2=Broad-Crested Rectangular Weir (Weir Controls 3.07 cfs @ 1.73 fps) T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com Appendix D: TSS Removal Calculation Worksheet Terrence R. Reynolds, P.E.TSS Removal Calculation WorksheetName: 504 Easthampton RoadProj. No.: 23-0705Date: 10/9/23Location: Northampton, MAComputed by: TRTreatment Train TSS Removal ABCDEBMPTSS Removal Starting TSSAmountRemainingRateLoad*Removed (BxC) Load (C-D) Total TSS Removal= Notes:0.20Infiltration basin80*Starting TSS Load for first BMP= 1.00. TSS load for subsequent BMP's is equal to the Remaining Load (E) from the previous BMP.80%1.000.8 T Reynolds Engineering 504 Easthampton Road, Northampton Civil Engineers- Planning, Design and Permitting Services Stormwater Drainage Report 10/26/2023 152 Maplewood Terrace, Florence, MA 01062 Phone: 413-387-80787, Fax: 413-727-3477 Email: terry@treynoldsengineering.com Appendix E: BMPs Checklist Bmps Checklist.doc 504 Easthampton Road, Northampton, Massachusetts Best Management Practices – Maintenance/ Evaluation Checklist Construction Practices Best Management Practice Inspection Frequency Date Inspected Inspector Minimum Maintenance and Key Items to Check Cleaning/Repair Needed yes no (List Items)Date of Cleaning/RepairPerformed by Erosion Control Barriers Once a month and immediately following any major storm event. Gravel Construction Entrance Once a month and immediately following any major storm event. Vegetated Slope Stabilization Once a month and immediately following any major storm event. Stormwater Control Manager Bmps Checklist.doc 504 Easthampton Road, Northampton, Massachusetts Best Management Practices – Maintenance/ Evaluation Checklist Long Term Practices Best Management Practice Inspection Frequency Date Inspected Inspector Minimum Maintenance and Key Items to Check Cleaning/Repair Needed yes no (List Items)Date of Cleaning/RepairPerformed by Infiltration/Water quality swale  Inspect soil and repair eroded areas monthly.  Remove litter and debris monthly. Treat diseased vegetation as needed. Remove and replace dead vegetation twice per year (spring and fall).  Remove invasive species as needed to prevent these species from spreading into the bioretention area. Replace mulch every two years, in the early spring.  Re-mulch void areas as needed. Upon failure, excavate bioretention area, scarify bottom and sides, replace filter fabric and soil, replant, and mulch. Stormwater Control Manager