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013025 NOI 181 Oldham Road - Appendix E - Stormwater Report
Town of Barnstable, MA DEPARTMENT OF PUBLIC WORKS NOTICE OF INTENT APPENDIX E Stormwater Checklist and Report westonandsampson.com Appendix E Stormwater Checklist and Report westonandsampson.com APPENDIX E.1 Stormwater Checklist 1-Stormwater Report Checklist.doc • 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. 1-Stormwater Report Checklist.doc • 04/01/08 Stormwater Report Checklist • Page 2 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report B. Stormwater Checklist and Certification The following checklist is intended to serve as a guide for applicants as to the elements that ordinarily need to be addressed in a complete Stormwater Report. The checklist is also intended to provide conservation commissions and other reviewing authorities with a summary of the components necessary for a comprehensive Stormwater Report that addresses the ten Stormwater Standards. Note: Because stormwater requirements vary from project to project, it is possible that a complete Stormwater Report may not include information on some of the subjects specified in the Checklist. If it is determined that a specific item does not apply to the project under review, please note that the item is not applicable (N.A.) and provide the reasons for that determination. A complete checklist must include the Certification set forth below signed by the Registered Professional Engineer who prepared the Stormwater Report. Registered Professional Engineer’s Certification I have reviewed the Stormwater Report, including the soil evaluation, computations, Long-term Pollution Prevention Plan, the Construction Period Erosion and Sedimentation Control Plan (if included), the Long- term Post-Construction Operation and Maintenance Plan, the Illicit Discharge Compliance Statement (if included) and the plans showing the stormwater management system, and have determined that they have been prepared in accordance with the requirements of the Stormwater Management Standards as further elaborated by the Massachusetts Stormwater Handbook. I have also determined that the information presented in the Stormwater Checklist is accurate and that the information presented in the Stormwater Report accurately reflects conditions at the site as of the date of this permit application. Registered Professional Engineer Block and Signature Signature and Date Checklist Project Type: Is the application for new development, redevelopment, or a mix of new and redevelopment? New development Redevelopment Mix of New Development and Redevelopment 1-Stormwater Report Checklist.doc • 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): Pretreatment reduction due to compliance with LID Credit 1 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. 1-Stormwater Report Checklist.doc • 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. 1-Stormwater Report Checklist.doc • 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. 1-Stormwater Report Checklist.doc • 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. 1-Stormwater Report Checklist.doc • 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. 1-Stormwater Report Checklist.doc • 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. westonandsampson.com APPENDIX E.2 Stormwater Narrative Stormwater Report To Be Submitted with the Notice of Intent Project Name: Route 28 West Sewer Expansion Project Applicant: Town of Barnstable Department of Public Works 382 Falmouth Road Hyannis, MA 02601 Pump Station Address: 181 Oldham Road Application Prepared by: Michael E. Paulin P.E. Weston & Sampson, Inc. 55 Walkers Brook Drive Reading, MA 01867 LID Measures The Massachusetts Stormwater Handbook encourages environmentally sensitive site design involving the incorporation of low impact development (LID) measures. The following techniques were taken into consideration during the design of the Route 28 West Sewer Expansion Project: 1.) Reducing impervious surfaces The area of impervious surface was kept to a minimum while still allowing for essential pump station operations. The pump station building was designed to be only as large as necessary to accommodate necessary pumping equipment. The driveway was designed to accommodate service truck parking and maneuvering while also limiting the amount of paved impervious area on site. The entire pump station site is proposed outside of the 50-foot no build zone per the Barnstable Conservation Commission regulations. 2.) Disconnecting flow paths The proposed pump station site will not be connected to the Town’s stormwater system. Stormwater will be collected and infiltrated back into the groundwater system through the use of several BMP techniques. Reduction in total suspended solids (TSS) of the stormwater will also be accomplished through this process. 3.) Treating stormwater at its source All stormwater from the pump station site will be collected and treated at the source through the use of BMPs located as close to the source as possible. The BMPs will be capable of 80% removal of TSS. 4.) Maximizing open space The pump station will be built within a footprint that is less than a quarter acre in size on a Town-owned parcel that has an overall area of close to 0.35 acres. The proposed design creates the smallest footprint within the site resulting in the maximization of open space. 5.) Minimizing disturbance By implementing a design that maximizes open space as described in item 4 above, the disturbance to the surrounding area will be minimized. Installation of sewer force mains will occur within the roadways in order to avoid any new disturbances. 6.) Protecting natural features and processes Existing vegetation will be preserved around the perimeter of the pump station site. Natural hydrologic processes are designed to approximate existing conditions by providing for onsite stormwater infiltration. Pretreatment of the stormwater will be provided prior to recharge into the groundwater system. Below is an explanation concerning Standards 1-10 as they apply to the Route 28 West Sewer Expansion Project: Standard 1: No New Untreated Discharges The proposed project will create no new untreated discharges to wetlands or waterways. During construction, to ensure that the work incorporates the performance standards recommended in the DEP’s Stormwater Management Policy, straw wattles/compost socks will be placed as depicted on the plans so that stormwater mitigation of silt to wetland resource areas will be minimized. Sewer and force main construction will take place within both cross country easements and the roadway that is an already disturbed, impervious area. At the completion of the project, the surfaces disturbed during the project will be returned to their pre-construction condition. The construction of the sewer and force main will not create new untreated discharge or impervious area. The pump station site will create new impervious area. The pump station site design includes directing runoff to a new deep sump catch basin for pretreatment. Adequate reduction of total suspended solids will then be achieved through the use of a leaching basin. Standard 2: Peak Rate Attenuation Sewer and force main construction will take place within the roadway that is an already disturbed, impervious area. At the completion of the project, the surfaces disturbed during the project will be returned to their pre-construction condition. Construction at the pump station site will include best management practices that collect and treat runoff with a minimum 80% treatment level. Stormwater runoff from the proposed driveway will be directed to an infiltration trench along the downslope edge of pavement. All runoff from the rooftop and driveway will be infiltrated on-site except for a de minimis portion of the driveway apron that is required so as to not introduce gutter flow within the right-of-way into the site. Summary of peak rates of runoff for the design storm events to the two points of comparison are summarized below. Design Storm Existing Condition Peak Flows (cfs) Proposed Condition Peak Flows (cfs) Design Point A Design Point B Design Point A Design Point B 1-year (2.88 “/24h) 0.0 0.0 0.0 0.0 2-year (2.88 “/24h) 0.0 0.0 0.0 0.0 10-year (2.88 “/24h) 0.0 0.0 0.0 0.0 25-year (2.88 “/24h) 0.0 0.0 0.0 0.0 100-year (2.88 “/24h) 0.0 0.0 0.0 0.0 To ensure that the work incorporates the performance standards recommended in the DEP’s Stormwater Management Policy, necessary erosion and sedimentation control measures will be utilized during construction. These measures will include straw wattles/compost socks as well as catch basin protection as depicted on the plans. Standard 3: Recharge Sewer and force main construction will take place within the roadway that is an already disturbed, impervious area. At the completion of the project, the surfaces disturbed during the project will be returned to their pre-construction condition. Since the impervious areas of the roadways will not change, the recharge of groundwater for this portion of the work will not be changed. At the pump station site, recharge to the groundwater or wetlands will be provided by an infiltration trench along the downhill slope of the driveway. The runoff from rooftops and pavement at the pump station site will be directed the BMP sized to infiltrate all runoff through the 100-year storm event. The proposed drainage system is designed so that recharge rates will not change in the work area at the end of the project. The recharge volume calculations are attached to this report (Attachment A) and show that the recharge volume will be drawn down well within the established time requirement. Standard 4: Water Quality This sewer extension provides an alternative to on-site wastewater disposal issues that would have persisted without construction of this project. As such, water quality at the site will be improved from the water quality at the start of the project. Sewer and force main construction will take place within the roadway that is an already disturbed, impervious area. At the completion of the project, the surface area disturbed during the project will be returned to its previous condition before the start of the project. Since the impervious area of the roadways will not change, water quality for this portion of the work will not be changed. The bordering vegetated wetlands that surround a portion of the new construction will aid water quality impacts since the vegetation in these areas reduce soil pollutants’ ability to venture into waterways. During the construction of the project, appropriate BMPs will be used to minimize sedimentation and soil erosion. These measures will include straw wattles/compost socks as depicted on the plans. At the pump station site, an infiltration trench designed to remove a minimum of 80% TSS will be provided to treat runoff from newly created impervious surfaces. Due to the low use of the proposed driveway and inclusion of clean rooftop runoff pre-treatment is provided via a sacrificial pea-stone diaphragm placed above a layer of filter fabric. This pea-stone diaphragm will provide removal of trash and large suspended solids. Attached to this report (Attachment B) is a TSS removal worksheet indicating that approximately 80% of TSS are being removed. The Project is also subject to environmentally sensitive design credits as (based upon the analyzed area only and not the total site area): The total impervious is less than 6% of the analyzed area No alteration is proposed within resource areas No work is proposed within the 50-foot buffer zone to the resource area Rooftop runoff is being wholly infiltrated This credit allows for the reduction of the water quality volume and recharge volume by up to 100-percent. The Applicant is not seeking relief from either requirement beyond the pre-treatment recommendation(s) for infiltration BMPs. Standard 5: Land Uses with Higher Potential Pollutant Loads (LUHPPLs) There are no LUHPPLs in the work area. Standard 6: Critical Areas The project does not discharge to critical areas. Standard 7: Redevelopments and Other Projects Subject to the Standards Only to the Maximum Extent Practicable A portion of the project, the installation of sewers in the roadway, is subject to the stormwater standards only to the maximum extent possible because it is a Limited Project under the provisions of 310 CMR 10.53 (3) (d). Standard 8: Construction Period Pollution Prevention and Erosion and Sediment Control A detailed Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan is attached to this report (Attachment C). To ensure that the work incorporates the performance standards recommended in the DEP’s Stormwater Management Policy, necessary erosion and sedimentation control measures will be utilized during construction. These measures will include straw wattles/compost socks as depicted on the site plans. Standard 9: Operation and Maintenance Plan A draft Storm Water Pollution Prevention Plan (SWPPP) for the project area is attached to this report (Attachment D). An operations and maintenance plan for the deep sump catch basin and leaching basin structure is attached to this report (Attachment E). Operation and Maintenance plans for the proposed pump station will be developed upon construction. Standard 10: Prohibition of Illicit Discharges The attached draft SWPPP addresses prevention of illicit discharges. Registered Professional Engineer’s Certification I have reviewed the Stormwater Report, including the soil evaluation, computations, Long-term Pollution Prevention Plan, the Construction Period Erosion and Sedimentation Control Plan (if included), the Long-term Post-Construction Operation and Maintenance Plan, the Illicit Discharge Compliance Statement (if included) and the plans showing the stormwater management system, and have determined that they have been prepared in accordance with the requirements of the Stormwater Management Standards as further elaborated by the Massachusetts Stormwater Handbook. I have also determined that the information presented in the Stormwater Checklist is accurate and that the information presented in the Stormwater Report accurately reflects conditions at the site as of the date of this permit application. Registered Professional Engineer Block and Signature Signature and Date \\wse03.local\WSE\Projects\MA\Barnstable MA\221360 Route 28 West Sewer Expansion Design\Permits\Conservation Commission\Stormwater Report\2-Stormwater Report.doc westonandsampson.com APPENDIX E.3 Calculations STORMWATER REPORT ATTACHEMENT A WATER QUALITY VOLUME/RECHARGE CALCULATIONS Route 28 West Sewer Expansion Project, Barnstable, MA Standard 3: Recharge 1. Soil Data See attached boring log PS-5 (#181 Oldham Road PS Site) Boring indicates fine to coarse Sands The less restrictive Sand is equivalent to NRCS soil type A, therefore the Target Depth Factor, F = 0.6 inches 2. Required Recharge Volume Rv = F x A Rv = Recharge Volume F = Recharge Target Depth Factor Based on NRCS Soil Type A = Impervious Area Oldham Road Pump Station A = 616 ft2 (Driveway/Building) Rv = (0.6/12) x 613 = 30.8 ft3 3. Sizing – using “Static Method” The “Static” Method assumes that there is no exfiltration until the entire recharge device is filled to the elevation associated with the Required Recharge Volume. The “Static” Method produces a larger storage volume than either Dynamic Method and produces the most conservative result. Using the “Static” Method, the storage volume is equivalent to the recharge volume. 4. Drawdown within 72 hours Use the same infiltration rate that is used for sizing the infiltration BMP to confirm that the infiltration BMP will drain completely within 72 hours. Timedrawdown = Rv / K x AB bottom area of structure K = 8.27 in/hr for sand AB = bottom area of structure 43’ long x 2’ wide x 3’ deep infiltration trench (n=0.4) AB = 43’ x 2’ = 86 sf. Oldham Road Pump Station Rv = 30.8 ft3 Td = 30.8 / ((8.27/12) x 86) = 0.5 hours 0.5 hours < 72 hours, result is satisfactory for design purposes Standard 4: Water Quality 1. Analysis Point All storm water flow will be directed to the proposed infiltration trench along the downside slope of the proposed driveway. Analysis point A was taken at the edge of the BVW and analysis point B represents the de minimis flows to Oldham Road. 2. Watershed Delineation The proposed BMP treatment train will incorporate the stormwater flow from 92-percent of impervious surfaces at the entire proposed pump station site. Therefore, the watershed will comprise the proposed pump station site. 3. Impervious Area Proposed Pump Station Building 12’ x 15’ = 180 ft2 Proposed Driveway and Concrete Apron 436 ft2 Total Impervious Area 616 ft2 Water Quality Volume (1/12) ft x 616 ft2 = 51.1 ft3 Required Provided: 43’ long x 2’ wide x 3’ deep infiltration trench (n=0.4) = 103.2 ft 3 provided \\wse03.local\WSE\Projects\MA\Barnstable MA\221360 Route 28 West Sewer Expansion Design\Permits\Conservation Commission\Stormwater Report\3-Recharge Calculations.docx STORMWATER REPORT ATTACHMENT B Project: Route 28 West Sewer Expansion Project Location: Barnstable, MA Prepared By: Weston & Sampson Engineers, Inc. Date: January 28, 2025 TSS Removal Calculation Worksheet A B C D E BMP Type TSS Removal Rate Starting TSS Load* Amount Removed (BxC) Remaining Load (C-D) Infiltration Trench 0.80 1.0 0.8 0.2 Total TSS Removal = 0.8 * Equals remaining load from previous BMP (column E). A OVERLAND FLOW TO WETLAND Routing Diagram for HYDRO-EX Prepared by Weston & Sampson Engineers, Inc, Printed 1/28/2025 HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Subcat Reach Pond Link Existing Conditions - Pump Station 5 HYDRO-EX Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 2HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Rainfall Events Listing Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 1-Year Type III 24-hr Default 24.00 1 2.88 2 2 2-Year Type III 24-hr Default 24.00 1 3.40 2 3 10-Year Type III 24-hr Default 24.00 1 4.96 2 4 25-year Type III 24-hr Default 24.00 1 5.93 2 5 100YEAR Type III 24-hr Default 24.00 1 7.43 2 Existing Conditions - Pump Station 5 Type III 24-hr 1-Year Rainfall=2.88"HYDRO-EX Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 3HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 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=9,540 sf 0.00% Impervious Runoff Depth=0.00"Subcatchment A: OVERLAND FLOW TO Flow Length=74' Slope=0.0718 '/' Tc=9.8 min CN=30 Runoff=0.00 cfs 0 cf Total Runoff Area = 9,540 sf Runoff Volume = 0 cf Average Runoff Depth = 0.00" 100.00% Pervious = 9,540 sf 0.00% Impervious = 0 sf Existing Conditions - Pump Station 5 Type III 24-hr 1-Year Rainfall=2.88"HYDRO-EX Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 4HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment A: OVERLAND FLOW TO WETLAND Runoff = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Depth= 0.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 1-Year Rainfall=2.88" Area (sf) CN Description 9,540 30 Woods, Good, HSG A 9,540 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.8 74 0.0718 0.13 Sheet Flow, SHEET Woods: Light underbrush n= 0.400 P2= 3.40" Existing Conditions - Pump Station 5 Type III 24-hr 2-Year Rainfall=3.40"HYDRO-EX Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 5HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 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=9,540 sf 0.00% Impervious Runoff Depth=0.00"Subcatchment A: OVERLAND FLOW TO Flow Length=74' Slope=0.0718 '/' Tc=9.8 min CN=30 Runoff=0.00 cfs 0 cf Total Runoff Area = 9,540 sf Runoff Volume = 0 cf Average Runoff Depth = 0.00" 100.00% Pervious = 9,540 sf 0.00% Impervious = 0 sf Existing Conditions - Pump Station 5 Type III 24-hr 2-Year Rainfall=3.40"HYDRO-EX Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 6HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment A: OVERLAND FLOW TO WETLAND Runoff = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Depth= 0.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 2-Year Rainfall=3.40" Area (sf) CN Description 9,540 30 Woods, Good, HSG A 9,540 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.8 74 0.0718 0.13 Sheet Flow, SHEET Woods: Light underbrush n= 0.400 P2= 3.40" Existing Conditions - Pump Station 5 Type III 24-hr 10-Year Rainfall=4.96"HYDRO-EX Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 7HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 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=9,540 sf 0.00% Impervious Runoff Depth=0.00"Subcatchment A: OVERLAND FLOW TO Flow Length=74' Slope=0.0718 '/' Tc=9.8 min CN=30 Runoff=0.00 cfs 3 cf Total Runoff Area = 9,540 sf Runoff Volume = 3 cf Average Runoff Depth = 0.00" 100.00% Pervious = 9,540 sf 0.00% Impervious = 0 sf Existing Conditions - Pump Station 5 Type III 24-hr 10-Year Rainfall=4.96"HYDRO-EX Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 8HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment A: OVERLAND FLOW TO WETLAND Runoff = 0.00 cfs @ 24.00 hrs, Volume= 3 cf, Depth= 0.00" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 10-Year Rainfall=4.96" Area (sf) CN Description 9,540 30 Woods, Good, HSG A 9,540 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.8 74 0.0718 0.13 Sheet Flow, SHEET Woods: Light underbrush n= 0.400 P2= 3.40" Existing Conditions - Pump Station 5 Type III 24-hr 25-year Rainfall=5.93"HYDRO-EX Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 9HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 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=9,540 sf 0.00% Impervious Runoff Depth=0.06"Subcatchment A: OVERLAND FLOW TO Flow Length=74' Slope=0.0718 '/' Tc=9.8 min CN=30 Runoff=0.00 cfs 52 cf Total Runoff Area = 9,540 sf Runoff Volume = 52 cf Average Runoff Depth = 0.06" 100.00% Pervious = 9,540 sf 0.00% Impervious = 0 sf Existing Conditions - Pump Station 5 Type III 24-hr 25-year Rainfall=5.93"HYDRO-EX Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 10HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment A: OVERLAND FLOW TO WETLAND Runoff = 0.00 cfs @ 15.65 hrs, Volume= 52 cf, Depth= 0.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 25-year Rainfall=5.93" Area (sf) CN Description 9,540 30 Woods, Good, HSG A 9,540 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.8 74 0.0718 0.13 Sheet Flow, SHEET Woods: Light underbrush n= 0.400 P2= 3.40" Existing Conditions - Pump Station 5 Type III 24-hr 100YEAR Rainfall=7.43"HYDRO-EX Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 11HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 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=9,540 sf 0.00% Impervious Runoff Depth=0.29"Subcatchment A: OVERLAND FLOW TO Flow Length=74' Slope=0.0718 '/' Tc=9.8 min CN=30 Runoff=0.01 cfs 233 cf Total Runoff Area = 9,540 sf Runoff Volume = 233 cf Average Runoff Depth = 0.29" 100.00% Pervious = 9,540 sf 0.00% Impervious = 0 sf Existing Conditions - Pump Station 5 Type III 24-hr 100YEAR Rainfall=7.43"HYDRO-EX Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 12HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment A: OVERLAND FLOW TO WETLAND Runoff = 0.01 cfs @ 12.55 hrs, Volume= 233 cf, Depth= 0.29" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 100YEAR Rainfall=7.43" Area (sf) CN Description 9,540 30 Woods, Good, HSG A 9,540 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.8 74 0.0718 0.13 Sheet Flow, SHEET Woods: Light underbrush n= 0.400 P2= 3.40" A OVERLAND FLOW TO WETLAND A.1 FLOW TO INFILTRATION TRENCH B OVERLAND TO OLDHAM RD IT.1 Infiltration trench DP "A" DESIGN POINT "A" Routing Diagram for HYDRO-PRO Prepared by Weston & Sampson Engineers, Inc, Printed 1/28/2025 HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Subcat Reach Pond Link Proposed Condition HYDRO-PRO Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 2HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Rainfall Events Listing Event# Event Name Storm Type Curve Mode Duration (hours) B/B Depth (inches) AMC 1 1 Year Type III 24-hr Default 24.00 1 2.88 2 2 2 Year Type III 24-hr Default 24.00 1 3.40 2 3 10 Year Type III 24-hr Default 24.00 1 4.96 2 4 25 Year Type III 24-hr Default 24.00 1 5.93 2 5 100 YEAR Type III 24-hr Default 24.00 1 7.43 2 Proposed Condition Type III 24-hr 100 YEAR Rainfall=7.43"HYDRO-PRO Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 3HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Time span=0.00-72.00 hrs, dt=0.05 hrs, 1441 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Runoff Area=8,559 sf 0.27% Impervious Runoff Depth=0.35"Subcatchment A: OVERLAND FLOW TO Flow Length=74' Slope=0.0718 '/' Tc=9.8 min CN=31 Runoff=0.02 cfs 251 cf Runoff Area=883 sf 61.49% Impervious Runoff Depth=4.53"Subcatchment A.1: FLOW TO INFILTRATION Tc=6.0 min CN=75 Runoff=0.11 cfs 333 cf Runoff Area=97 sf 51.55% Impervious Runoff Depth=3.87"Subcatchment B: OVERLAND TO OLDHAM RD Tc=6.0 min CN=69 Runoff=0.01 cfs 31 cf Peak Elev=18.90' Storage=0.001 af Inflow=0.11 cfs 333 cfPond IT.1: Infiltration trench Discarded=0.04 cfs 333 cf Primary=0.00 cfs 0 cf Outflow=0.04 cfs 333 cf Inflow=0.02 cfs 251 cfLink DP "A": DESIGN POINT "A" Primary=0.02 cfs 251 cf Total Runoff Area = 9,539 sf Runoff Volume = 615 cf Average Runoff Depth = 0.77" 93.54% Pervious = 8,923 sf 6.46% Impervious = 616 sf Proposed Condition Type III 24-hr 100 YEAR Rainfall=7.43"HYDRO-PRO Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 4HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Summary for Subcatchment A: OVERLAND FLOW TO WETLAND Runoff = 0.02 cfs @ 12.50 hrs, Volume= 251 cf, Depth= 0.35" Routed to Link DP "A" : DESIGN POINT "A" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 100 YEAR Rainfall=7.43" Area (sf) CN Description 1,196 39 >75% Grass cover, Good, HSG A 7,340 30 Woods, Good, HSG A 23 98 Unconnected pavement, HSG A 8,559 31 Weighted Average 8,536 99.73% Pervious Area 23 0.27% Impervious Area 23 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.8 74 0.0718 0.13 Sheet Flow, SHEET Woods: Light underbrush n= 0.400 P2= 3.40" Summary for Subcatchment A.1: FLOW TO INFILTRATION TRENCH Runoff = 0.11 cfs @ 12.09 hrs, Volume= 333 cf, Depth= 4.53" Routed to Pond IT.1 : Infiltration trench Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 100 YEAR Rainfall=7.43" Area (sf) CN Description 340 39 >75% Grass cover, Good, HSG A 543 98 Paved parking, HSG D 883 75 Weighted Average 340 38.51% Pervious Area 543 61.49% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Summary for Subcatchment B: OVERLAND TO OLDHAM RD Runoff = 0.01 cfs @ 12.09 hrs, Volume= 31 cf, Depth= 3.87" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Type III 24-hr 100 YEAR Rainfall=7.43" Proposed Condition Type III 24-hr 100 YEAR Rainfall=7.43"HYDRO-PRO Printed 1/28/2025Prepared by Weston & Sampson Engineers, Inc Page 5HydroCAD® 10.20-6a s/n 00455 © 2024 HydroCAD Software Solutions LLC Area (sf) CN Description 50 98 Paved parking, HSG A 47 39 >75% Grass cover, Good, HSG A 97 69 Weighted Average 47 48.45% Pervious Area 50 51.55% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Min. Tc Summary for Pond IT.1: Infiltration trench Inflow Area = 883 sf, 61.49% Impervious, Inflow Depth = 4.53" for 100 YEAR event Inflow = 0.11 cfs @ 12.09 hrs, Volume= 333 cf Outflow = 0.04 cfs @ 12.32 hrs, Volume= 333 cf, Atten= 58%, Lag= 13.5 min Discarded = 0.04 cfs @ 12.32 hrs, Volume= 333 cf Primary = 0.00 cfs @ 12.30 hrs, Volume= 0 cf Routed to Link DP "A" : DESIGN POINT "A" Routing by Dyn-Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs Peak Elev= 18.90' @ 12.32 hrs Surf.Area= 0.002 ac Storage= 0.001 af Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 8.8 min ( 826.0 - 817.2 ) Volume Invert Avail.Storage Storage Description #1 17.20' 0.002 af 2.00'W x 43.00'L x 3.00'H Prismatoid 0.006 af Overall x 40.0% Voids Device Routing Invert Outlet Devices #1 Discarded 17.20'8.000 in/hr Exfiltration over Wetted area #2 Primary 18.90'4.0" Round Culvert L= 5.0' CPP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 18.90' / 18.75' S= 0.0300 '/' Cc= 0.900 n= 0.011, Flow Area= 0.09 sf Discarded OutFlow Max=0.04 cfs @ 12.32 hrs HW=18.90' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.04 cfs) Primary OutFlow Max=0.00 cfs @ 12.30 hrs HW=18.90' TW=0.00' (Dynamic Tailwater) 2=Culvert (Inlet Controls 0.00 cfs @ 0.11 fps) Summary for Link DP "A": DESIGN POINT "A" Inflow Area = 9,442 sf, 5.99% Impervious, Inflow Depth = 0.32" for 100 YEAR event Inflow = 0.02 cfs @ 12.50 hrs, Volume= 251 cf Primary = 0.02 cfs @ 12.50 hrs, Volume= 251 cf, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-72.00 hrs, dt= 0.05 hrs westonandsampson.com APPENDIX E.4 Construction Period Prevention Plan CPPPESCP -1 STORMWATER REPORT ATTACHMENT C CONSTRUCTION PERIOD POLLUTION PREVENTION AND EROSION AND SEDIMENTATION CONTROL PLAN 1. INTRODUCTION This Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan (CPPPESCP) is for the Route 28 West Sewer Expansion Project and is part of the Notice of Intent. The sewer extension project consists of one submersible pump station. Runoff from the pump station site will be discharged for recharge. It is estimated that 80% of TSS will be removed by the proposed infiltration trench. Stormwater controls used during the construction period will include straw wattles/compost socks, silt fences and bentonite dams that will be utilized to prevent siltation in wetland areas. 2. CONTACT INFORMATION/RESPONSIBLE PARTIES Contractor: To be determined through bidding process Consultant: Michael E. Paulin, P.E. Weston & Sampson Engineers, Inc. 55 Walker’s Brook Drive, Reading, MA 01867 978-532-1900 Owner: Griffin Beaudoin, P.E., Town Engineer Barnstable Department of Public Works 382 Falmouth Road Hyannis, MA 02601 (508) 790-6400 3. CONSTRUCTION PERIOD OPERATION AND MAINTENANCE PLAN Best Management Practices (BMPs) will be utilized as Construction Period Pollution Prevention Measures to prevent any siltation into wetland areas. The objectives of the BMPs for construction activity are to minimize the disturbed areas, stabilize any disturbed areas, control the site perimeter and retain sediment. Erosion and sedimentation controls will be used to minimize site disturbance and ensure compliance with the performance standards of the WPA and Stormwater Standards. Measures will be taken to minimize the area disturbed by construction activities to reduce the potential for soil erosion and stormwater pollution problems. In addition, good housekeeping measures will be followed for the day-to-day operation of the construction site under the control of the contractor to minimize the impact of construction. This section describes the control practices that will be in place during construction activities. All recommended control practices will comply with the standards set in the MA DEP Stormwater Policy Handbook. CPPPESCP -2 3.1 Minimize Disturbed Area and Protect Natural Features and Soil In order to minimize disturbed areas, all work will be completed within well-defined work limits. These work limits are shown on the plans. The Contractor shall not disturb native vegetation in the undisturbed wetland area without prior approval from the Engineer outside the limit or work. The Contractor will be responsible to make sure that all workers know the proper work limits and do not extend their work into the undisturbed areas. The protective measures are described in more detail in the following sections. 3.2 Phased Construction Activity Phased construction is not necessary for this project. 3.3 Control Stormwater Flowing Onto and Through the Project The contractor will be required to install straw wattles/compost socks around the perimeter of the work areas so that soils cannot migrate off-site. Catch basin protection will be installed as shown on the plans for additional sedimentation protection. 3.4 Stabilize Soils The Contractor shall limit the area of land which is exposed and free from vegetation during construction. 3.5 Proper Storage and Cover of Any Stockpiles The location of the Contractor's storage areas for equipment and/or materials shall require written approval of the Engineer. No excavated materials or materials used in backfill operations shall be stored within a minimum distance of one hundred (100) feet of any wetlands. Adequate measures for erosion and sediment control such as the placement of straw wattles/compost socks around the downstream perimeter of stockpiles shall be employed to protect any downstream areas from siltation. There shall be no storage of equipment or materials within 100 feet of areas designated as wetlands or rivers. The Engineer may designate a particular area or areas where the Contractor may store materials used in his operations 3.6 Perimeter Controls and Sediment Barriers Erosion control lines as described in Section 6 will be utilized to ensure that no sedimentation occurs outside the perimeter of the work area. 3.7 Storm Drain Inlet Protection The storm drains in the work area will be protected with filter bags as depicted on the plans. CPPPESCP -3 3.8 Retain Sediment On-Site The Contractor will be responsible to monitor all erosion control measures. Whenever necessary the Contractor will clear all sediment from the straw wattles/compost socks that have been silted up during construction. The following good housekeeping practices will be followed on-site during the construction project: 3.9 Material Handling and Waste Management All materials stored on-site will be stored in a neat, orderly manner in appropriate containers. All materials will be kept in their original containers with the original manufacturer’s label. Substances will not be mixed with one another unless recommended by the manufacturer. All waste materials will be collected and stored in a securely lidded metal container from a licensed management company. The waste and any construction debris from the site will be hauled off-site daily and disposed of properly. The contractor will be responsible for all waste removal. Manufacturer’s recommendations for proper use and disposal will be followed for all materials. Sanitary waste will be collected from the portable units a minimum of once a week, by a licensed sanitary waste management contractor. 3.10 Designated Washout Areas The contractor shall use washout facilities at their own plants, unless otherwise directed by the engineer. The contractor shall provide contained concrete washout areas outside of wetland, buffer and resource areas. Concrete debris from washouts shall be properly disposed of off-site. Concrete washout areas and methods shall require approval of the Engineer. 3.11 Proper Equipment/Vehicle Fueling and Maintenance Practices On-site vehicles will be monitored for leaks and receive regular preventative maintenance to reduce the risk of leakage. To ensure that leaks on stored equipment do not contaminate the site oil- absorbing mats will be placed under all equipment during storage. Regular fueling and service of the equipment may be performed using approved methods and with care taken to minimize chance of spills. Repair of equipment or machinery within the 100’ water resources area shall not be allowed without the prior approval of the Engineer. Any petroleum products will be stored in tightly sealed containers that are clearly labeled. 3.12 Equipment/Vehicle Washing The Contractor will be responsible to ensure that no equipment is washed on-site except to remove sediments prior to transport from the site. Wheel washing will only be conducted in designated areas within the limits of work in order to prevent material from leaving the site. The contractor shall be responsible for designating a wheel wash area onsite. Areas must have sufficient containment volume to prevent sediment laden water from leaving the site. Wheel washing areas must be approved by the Engineer. It was determined that Type A soils were present on site, indicating a sandy type soil. It is projected that sediment will not adhere to construction equipment as readily as type B, C and D. CPPPESCP -4 4. SPILL PREVENTION AND CONTROL PLAN The Contractor will be responsible for preventing spills in accordance with the project specifications and applicable federal, state and local regulations. The Contractor will identify a properly trained site employee, involved with the day-to-day site operations to be the spill prevention and cleanup coordinator. The name(s) of the responsible spill personnel will be posted on-site. Each employee will be instructed that all spills are to be reported to the spill prevention and cleanup coordinator. 4.1 Spill Control Equipment Spill control/containment equipment will be kept in the Work Area. Materials and equipment necessary for spill cleanup will be kept either in the Work Area or in an otherwise accessible on-site location. Equipment and materials will include, but not be limited to, absorbent booms/mats, brooms, dust pans, mops, rags, gloves, goggles, sand, plastic and metal containers specifically for this purpose. It is the responsibility of the Contractor to ensure the inventory will be readily accessible and maintained. 4.2 Notification All workers will be directed to inform the on-site supervisor of a spill event. The supervisor will assess the incident and initiate proper containment and response procedures immediately upon notification. Workers should avoid direct contact with spilled materials during the containment procedures. Primary notification of a spill should be made to the Barnstable DPW and Fire Department. Secondary Notification will be to the certified cleanup contractor if deemed necessary by DPW and/or Fire. The third level of notification is to the DEP. The specific cleanup contractor to be used will be identified by the Contractor prior to commencement of construction activities. 4.3 Spill Containment and Clean-Up Measures Spills will be contained with granular sorbent material, sand, sorbent pads, booms or all of the above to prevent spreading. Certified cleanup contractors should complete spill cleanup. The material manufacturer’s recommended methods for spill cleanup will be clearly posted and on-site personnel will be made aware of the procedures and the location of the information and cleanup supplies. 4.4 Hazardous Materials Spill Report The Contractor will report and record any spill. The spill report will present a description of the release, including the quantity and type of material, date of the spill, circumstances leading to the release, location of spill, response actions and personnel, documentation of notifications and corrective measures implemented to prevent reoccurrence. : This document does not relieve the Contractor of the Federal reporting requirements of 40 CFR Part 110, 40 CFR Part 117, 40 CFR Part 302 and the State requirements specified under the Massachusetts Contingency Plan (M.C.P) relating to spills or other releases of oils or hazardous substances. Where a release containing a hazardous substance or oil in an amount equal to or in excess of a reportable quantity established under either 40 CFR Part 110, 40 CFR Part 117 or 40 CPPPESCP -5 CFR Part 302, occurs during a twenty-four (24) hour period, the Contractor is required to comply with the response requirements of the above mentioned regulations. Spills of oil or hazardous material in excess of the reportable quantity will be reported to the National Response Center (NRC). 5. OPERATION AND MAINTENANCE PLAN The Operations and Maintenance Plan is included in the Stormwater Pollution Prevention Plan. 6. EROSION AND SEDIMENTATION CONTROL Erosion and Sedimentation Controls can be found on the site plans. In addition, Erosion and Sedimentation Controls can be found with the technical specifications, Section 01570 Environmental Protection. 7. VEGETATIVE PLANNING No vegetative planning is needed for this project. 8. SITE DEVELOPMENT PLAN No site development plan is needed for this project. 9. OPERATION AND MAINTENANCE OF SEDIMENTATION CONTROL The sedimentation control measures will be installed as detailed in the technical specification 01570 Environmental Protection (Appendix E). If there is a failure to the controls the contractor, under the supervision of the engineer, will be required to stop work until the failure is repaired. Periodically throughout the work, whenever the engineer deems it necessary, the sediment that has been deposited against the controls will be removed to ensure that the controls are working properly. 10. INSPECTION SCHEDULE During construction the erosion and sedimentation controls will be inspected twice daily. One inspection will occur in the morning and one inspection will occur at the end of the work day. An Inspection Form is included and must be completed by the end of each day. Inspection forms will be submitted to the Engineer at the end of the work week. \\wse03.local\WSE\Projects\MA\Barnstable MA\221360 Route 28 West Sewer Expansion Design\Permits\Conservation Commission\Stormwater Report\5-CPPPESCP.doc Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan Route 28 West Sewer Expansion Project Barnstable, Massachusetts Weston & Sampson Inspection Form Inspected By: _______________________________ Date: ___________Time:________ YES NO DOES NOT APPLY ITEM Do any erosion/siltation control measures, including those involved in dewatering operations, require repair or clean out to maintain adequate function? Are on-site construction traffic routes, parking, and storage of equipment and supplies located in areas not specifically designed for them? Are any temporary soil stockpiles or construction materials located in non-approved areas? Is there any evidence that sediment is leaving the site and entering the wetlands? If Erosion Control requires stabilization the current tasks should be completed: · Suspend any work that is creating erosion and sedimentation; · Clean any accumulated sediment buildup; · Remove failing erosion control; · Replace with new erosion control; · Test to confirm proper function. Specific location, current weather conditions, and action to be taken: ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ ________________________________________________________________________ Other Comments: ________________________________________________________________________ ________________________________________________________________________ Pending the actions noted above I certify that the site is in compliance with the Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan. Signature: ______________________________ Date: ___________________________ westonandsampson.com Appendix E.5 Stormwater Pollution Prevention Plan STORMWATER REPORT ATTACHMENT D SWPPP-1 Storm Water Pollution Prevention Plan Project Name: Route 28 West Sewer Expansion Project Facility Name: Barnstable Department of Public Works Facility Address: 382 Falmouth Road, Hyannis, MA, 02601 1. STORM WATER POLLUTION PREVENTION PLAN (SWPPP) OVERVIEW This Storm Water Pollution Prevention Plan is for the Route 28 West Sewer Expansion Project and is part of the Notice of Intent. This SWPPP: identifies the SWPPP coordinator with a description of the coordinator’s duties; identifies members of the SWPPP team and lists their responsibilities; describes the facility and the storm water drainage system; identifies potential storm water contaminants; describes storm water management controls and various Best Management Practices (BMPs) needed to reduce pollutants in storm waster discharges; describes the facility’s monitoring plan. 2. PLANNING AND ORGANIZATION 2.1. SWPPP Coordinator and Team Leader: ___Griffin Beaudoin __ Office Phone: _(508) 790-6400_ Title: Town Engineer__ Responsibilities: Coordinate all stages of roadway drainage construction, inspections and implementation; keep all records and ensure that reports are submitted; maintain long-term maintenance program of BMPs. Member: _Michael Tieu_ Office Phone: _(508) 790-6400_ Title: _ Senior Project Manager_ Cell Phone/Beeper # _(774) 487-7816_ Responsibilities: Implement and oversee the maintenance program; oversee good housekeeping activities. 3. ASSESSMENT 3.1. Site Description This section of the Route 28 West Sewer Expansion Project consists of one (1) submersible pumping station. A Locus Map included in this submittal illustrates the general project location. After STORMWATER REPORT ATTACHMENT D SWPPP-2 pretreatment, runoff from the pump station site will be discharged for recharge. It is estimated that 85% of TSS will be removed by the deep sump catch basin and leaching basin. 3.2. Site Map The site map and drainage are shown on the plans prepared by Weston & Sampson and submitted with the Notice of Intent. 3.3. Significant Material Inventory N/A 3.6 Spills and Leaks Spills or leaks on the roads will be handled by the Barnstable DPW and Fire Departments. Massachusetts DEP will be notified in the event a reportable spill occurs. 3.9. Existing Storm Water Monitoring Data N/A 3.10. Site Summary (Sources of pollution with a high risk of contaminating storm water) The most significant potential source of contamination will be the traffic on the road and maintenance of the road. In addition to oils and grease, road salt, etc. 4. IMPLEMENTATION This section describes practices that are in place or that will be implemented to control pollutants that have the potential to contaminate storm water. 4.1. Good Housekeeping The following is a list of good housekeeping practices that will be followed: Street sweeping will be done in accordance with Barnstable’s current schedule. 4.2. Preventive Maintenance The following is a list of preventive maintenance procedures practiced at this site: Catch basins will be cleaned bi-annually All inlet and outlet pipes will be maintained in working condition. 4.3. Best Management Practices (BMPs) The following is a list of existing and planned Best Management Practices. When implemented, the BMPs will prevent or reduce the discharge of potential pollutants in storm water runoff for the site. No vehicles, materials or equipment will be stored in wetland areas. Drainage structures will be maintained to ensure continued treatment of stormwater. 4.4. Sediment and Erosion Control Best management practices will be used during construction to avoid off site impacts associated with the project. Temporary straw wattles shall be utilized to help prevent siltation in wetland areas. A hazardous waste spill kit shall be on site at all times. STORMWATER REPORT ATTACHMENT D SWPPP-3 4.5. Management of Storm Water Runoff The following management practices for runoff are used at this facility. Proper sedimentation control measures will be implemented on site during construction. Straw wattles/compost socks will be installed along the edges of roads to prevent siltation of surrounding wetlands. Catch basin protection will be installed to prevent excess siltation of the existing stormwater system. 4.6. Spill Prevention and Response Spills or leaks or oil or hazardous materials on the access road will be handled by the Barnstable DPW and Fire Departments. Massachusetts DEP will be notified in the event a reportable spill occurs. 4.7. Employee Training Employees will be trained to use the equipment and to conduct the inspections necessary to maintain the stormwater system. 5. EVALUATION Visual evaluation of the effectiveness of stormwater controls will be made during regular inspections. 6. ENDANGERED SPECIES Best Management Practices will be used to minimize any impact from the site’s outfall to receiving waters. 7. HISTORIC PLACES The site is not located adjacent to any Listed Historic Sites or Districts. STORMWATER REPORT ATTACHMENT D SWPPP-4 8. CERTIFICATIONS Storm Water Pollution Prevention Plan This Storm Water Pollution Prevention Plan has been prepared in accordance with good engineering practices. Qualified personnel properly gathered and evaluated information submitted for this Plan. The information in this Plan, to the best of my knowledge, is accurate and complete. _______________________________ Name _______________________________ Title _______________________________ Date \\wse03.local\WSE\Projects\MA\Barnstable MA\221360 Route 28 West Sewer Expansion Design\Permits\Conservation Commission\Stormwater Report\7-swppp.doc westonandsampson.com APPENDIX E.6 Operations and Maintenance Plan STORMWATER REPORT ATTACHMENT E STORMWATER OPERATION AND MAINTENANCE PLAN BARNSTABLE DEPARTMENT OF PUBLIC WORKS BARNSTABLE, MA Infiltration Trench: Inspection: Remove accumulated sediment, trash, debris, leaves and grass clippings from mowing. Remove tree seedlings, before they become firmly established. Inspect the infiltration trench after the first several rainfall events, after all major storms, and on regularly scheduled dates every six months. If the top of the trench is grassed, it must be mowed on a seasonal basis. Grass height must be maintained to be no more than four inches. Routinely remove grass clippings leaves and accumulated sediment from the surface of the trench. Inspect the trench 24 hours or several days after a rain event, to look for ponded water. If there is ponded water at the surface of the trench, it is likely that the trench surface is clogged. Maintenance: To address surface clogging, remove and replace the topsoil or first layer of stone aggregate and the filter fabric. If water is ponded inside the trench, it may indicate that the bottom of the trench has failed. To rehabilitate a failed trench, all accumulated sediment must be stripped from the bottom, the bottom of the trench must be scarified and tilled to induce infiltration, and all of the stone aggregate and filter fabric or media must be removed and replaced. \\wse03.local\WSE\Projects\MA\Barnstable MA\221360 Route 28 West Sewer Expansion Design\Permits\Conservation Commission\Stormwater Report\8-Stormwater Operation and Maintenance Plan.doc westonandsampson.com APPENDIX E.7 Catchment Area Maps AS SHOWN AC AC KM EXISTING HYDROCAD MAP FIG-1 AX B-X P:\MA\Barnstable MA\221360 Route 28 West Sewer Expansion Design\Pump Station Design\CAD\Civil\Stormwater Design\EX-HYDROCAD.dwgCOPYRIGHT © 2024 WESTON & SAMPSON, INC. Project: www.westonandsampson.com Consultants: Seal: Revisions: No. Date Description Issued For: Drawing Title: Sheet Number: Scale: W&S File No.: W&S Project No.: Approved By: Date: Reviewed By: Drawn By: COA: TOWN OF BARNSTABLE, MASSACHUSETTS ROUTE 28 WEST SEWER EXPANSION PROJECT DEPARTMENT OF PUBLIC WORKS 382 FALMOUTH ROAD, HYANNIS, MA 02601 90% CONSTRUCTION DOCUMENTS NOV 13, 2024 ENG22-1360 Weston & Sampson Engineers, Inc. 55 Walkers Brook Drive, Suite 100 Reading, MA 01867 978.532.1900 800.SAMPSON THIS DOCUMENT AND ALL ASSOCIATED DOCUMENTS ARE PREPARED FOR THE EXCLUSIVE USE OF THE CLIENT SOLELY FOR THE SPECIFIC PROJECT LISTED ON THE FACE OF THIS DOCUMENT AND INCORPORATES CALCULATIONS AND MEASUREMENTS AVAILABLE FROM THE CLIENT AT THE TIME OF DRAFTING. THE RECIPIENT OF THIS DOCUMENT SHALL NOT DISTRIBUTE, DISSEMINATE, REPRODUCE OR COPY, IN WHOLE OR IN PART, WITHOUT THE WRITTEN PERMISSION OF WESTON & SAMPSON, INC. A 222222 222221 20 19 19202 1 21AS SHOWN CA AC KM PROPOSED HYDROCAD MAP FIG-2 P:\MA\Barnstable MA\221360 Route 28 West Sewer Expansion Design\Pump Station Design\CAD\Civil\Stormwater Design\PR-HYDROCAD.dwgCOPYRIGHT © 2024 WESTON & SAMPSON, INC. Project: www.westonandsampson.com Consultants: Seal: Revisions: No. Date Description Issued For: Drawing Title: Sheet Number: Scale: W&S File No.: W&S Project No.: Approved By: Date: Reviewed By: Drawn By: COA: TOWN OF BARNSTABLE, MASSACHUSETTS ROUTE 28 WEST SEWER EXPANSION PROJECT DEPARTMENT OF PUBLIC WORKS 382 FALMOUTH ROAD, HYANNIS, MA 02601 90% CONSTRUCTION DOCUMENTS NOV 13, 2024 ENG22-1360 Weston & Sampson Engineers, Inc. 55 Walkers Brook Drive, Suite 100 Reading, MA 01867 978.532.1900 800.SAMPSON THIS DOCUMENT AND ALL ASSOCIATED DOCUMENTS ARE PREPARED FOR THE EXCLUSIVE USE OF THE CLIENT SOLELY FOR THE SPECIFIC PROJECT LISTED ON THE FACE OF THIS DOCUMENT AND INCORPORATES CALCULATIONS AND MEASUREMENTS AVAILABLE FROM THE CLIENT AT THE TIME OF DRAFTING. THE RECIPIENT OF THIS DOCUMENT SHALL NOT DISTRIBUTE, DISSEMINATE, REPRODUCE OR COPY, IN WHOLE OR IN PART, WITHOUT THE WRITTEN PERMISSION OF WESTON & SAMPSON, INC. AX B-X A A B A-1 DEPTH BELOW GROUNDSURFACE [VERTICAL FT.]5 10 15 20 25 30 SAMPLE TYPE GRAPHICSAMPLE ID NUMBER ANDRECOVERY RATIO [IN./IN.]S-1 24/24 S-2 20/24 S-3 23/24 S-4 14/24 S-5 14/24 S-6 18/24 S-7 15/24 S-8 18/24 S-9 SPT BLOWS / 6 IN. (OR)CORE RATE / 12 IN. [MIN.]3 2 2 5 5 4 4 4 3 3 2 3 6 7 7 8 9 11 11 11 6 4 4 8 7 5 6 7 8 7 6 8 5 GEOTECHNICAL TEST DATA 4 8 5 14 22 8 11 13 STRATIGRAPHY LOGSTRATUM IDENTIFICATION AND DESCRIPTION Surface: Forest debris. Topsoil-3 inches thick. Poorly graded sand with silt (SP-SM)-Very loose; brown and dark gray; moist; mostly fine to medium SAND, few non plastic fines, trace fine to coarse gravel. Silty sand (SM)-Loose; light brown; moist; mostly fine to medium SAND, some non plastic fines, few fine gravel; trace roots. Poorly graded sand (SP)-Loose to medium dense; orange to gray; mostly fine to medium SAND, trace non plastic fines; occasional roots. Poorly graded sand (SP)-Medium dense; tan; mostly fine to medium SAND, trace non plastic fines. Sandy silt (ML)-Stiff; brown; mostly non plastic FINES, some fine sand. Poorly graded sand with silt (SP-SM)- Medium dense; brown; mostly fine to medium SAND, few non plastic fines. Silt (ML)-Stiff; gray; mostly non plastic FINES, few fine sand.ELEVATION SCALESHOWN TO NEAREST FT.17 12 7 2 -3 -8 -13 REMARKS, OTHER TESTS, AND INSTALLATIONS Note: Values in brackets preceeding a remark indicate depth below ground surface (in feet) corresponding to the remark. [4.0] Soil moisture not able to be evaluated below this depth due to the introduction of water for drilling purposes. [14.5 -5.0] Oxidized orange sand seam observed. Route 28 West Sewer Expansion Barnstable, MA BORING ID: PS-5WSE Project: ENG22-1360 Page 1 of 2 CONTRACTOR: FOREMAN: LOGGED BY: CHECKED BY: EQUIPMENT: SPT HAMMER: Geosearch, Inc. Darwin Newton Kathryn Lennon TJ Blair, PE CME 55, Truck Mounted Automatic (140-lb.) BORING LOCATION: ADVANCE METHOD: AUGER DIAMETER: SUPPORT CASING: CORING METHOD: BACKFILL MATERIAL: Off Oldham Rd. Rotary Wash Drilling N/A Driven Flush-Joint Casing (4" ID) N/A Drill Cuttings DATE START: DATE FINISH: GROUND EL: FINAL DEPTH: STATION: OFFSET: October 24, 2023 October 24, 2023 21.5 ± (NAVD88) 38.0 ft. 18+45 25.0 ft. R Refer to the attached index sheets for important information about this log including general notes,legends, and guidance on description methods and procedures. N-Value, Raw (bpf) Organic Content (%) 10 20 30 40 Moisture Content (%) Plastic Limit, PL (%) Liquid Limit, LL (%) 25 50 75 100 DEPTH BELOW GROUNDSURFACE [VERTICAL FT.]40 45 50 55 60 65 70 SAMPLE TYPE GRAPHICSAMPLE ID NUMBER ANDRECOVERY RATIO [IN./IN.]16/24 S-10 24/24 SPT BLOWS / 6 IN. (OR)CORE RATE / 12 IN. [MIN.]4 5 6 4 5 7 8 GEOTECHNICAL TEST DATA 9 12 STRATIGRAPHY LOGSTRATUM IDENTIFICATION AND DESCRIPTION Silt (ML)-Stiff; gray; mostly non plastic FINES, few fine sand.ELEVATION SCALESHOWN TO NEAREST FT.-18 -23 -28 -33 -38 -43 -48 -53 REMARKS, OTHER TESTS, AND INSTALLATIONS Note: Values in brackets preceeding a remark indicate depth below ground surface (in feet) corresponding to the remark. Exploration ended at 38.0 ft. Route 28 West Sewer Expansion Barnstable, MA BORING ID: PS-5WSE Project: ENG22-1360 Page 2 of 2 Refer to the attached index sheets for important information about this log including general notes,legends, and guidance on description methods and procedures. N-Value, Raw (bpf) Organic Content (%) 10 20 30 40 Moisture Content (%) Plastic Limit, PL (%) Liquid Limit, LL (%) 25 50 75 100 DEPTH BELOW GROUNDSURFACE [VERTICAL FT.]5 10 15 20 25 30 SAMPLE TYPE GRAPHICSAMPLE ID NUMBER ANDRECOVERY RATIO [IN./IN.]S-1 18/24 S-2 20/24 S-3 14/24 S-4 23/24 S-5 24/24 S-6 24/24 SPT BLOWS / 6 IN. (OR)CORE RATE / 12 IN. [MIN.]2 3 7 7 6 5 5 5 2 1 2 2 3 4 4 5 3 3 5 7 5 6 9 10 GEOTECHNICAL TEST DATA 10 10 3 8 8 15 STRATIGRAPHY LOGSTRATUM IDENTIFICATION AND DESCRIPTION Surface: Forest debris. Topsoil-1 inch thick. Poorly graded sand with silt (SP-SM)-Medium dense; brown; moist; mostly fine to medium SAND, few non plastic fines; trace roots. Poorly graded sand (SP)-Very loose; orange to gray; moist to wet; mostly fine to medium SAND, trace non plastic fines; trace roots. Poorly graded sand (SP)-Medium dense; brown to tan; wet; mostly fine to medium SAND, trace fine gravel, trace non plastic fines. Sandy silt (ML)-Brown; wet; mostly non plastic FINES, some fine sand. Poorly graded sand (SP)-Brown; wet; mostly fine to medium SAND, trace non plastic fines. Lean clay (CL)-Stiff; gray; wet; mostly low plasticity FINES, trace fine sand.ELEVATION SCALESHOWN TO NEAREST FT.15 10 5 0 -5 -10 -15 REMARKS, OTHER TESTS, AND INSTALLATIONS Note: Values in brackets preceeding a remark indicate depth below ground surface (in feet) corresponding to the remark. Water level measured at 4.3 ft. on 08/06/24 (well reading). [16.0] GC: 0%, SC: 96%, FC: 4% [16.5 -17.0] Oxidized orange sand seam observed. [21.0] GC: 0%, SC: 4%, FC: 96% Exploration ended at 22.0 ft. Route 28 West Sewer Expansion Barnstable, MA BORING ID: PS-5FWSE Project: ENG22-1360 Page 1 of 1 CONTRACTOR: FOREMAN: LOGGED BY: CHECKED BY: EQUIPMENT: SPT HAMMER: Geosearch, Inc. Donnie Watson Kathryn Lennon TJ Blair, PE Diedrich D-50, ATV Mounted Automatic (140-lb.) BORING LOCATION: ADVANCE METHOD: AUGER DIAMETER: SUPPORT CASING: CORING METHOD: BACKFILL MATERIAL: Off Oldham Rd. Hollow-Stem Auger Drilling 4-1/4" ID (Stem), 7-5/8" OD (Flights) N/A N/A Observation Well Installed DATE START: DATE FINISH: GROUND EL: FINAL DEPTH: STATION: OFFSET: June 21, 2024 June 21, 2024 19.5 ± (NAVD88) 22.0 ft. 18+12 36.0 ft. R Refer to the attached index sheets for important information about this log including general notes,legends, and guidance on description methods and procedures. N-Value, Raw (bpf) Organic Content (%) 10 20 30 40 Moisture Content (%) Plastic Limit, PL (%) Liquid Limit, LL (%) 25 50 75 100