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Home My WebLink About2019-06-04 Stormwater Mgmnt Report Rev 4.24.2019 STORMWA TER MANA GEMENT REPOR T Proposed Site Re Development for ENTERPRISE BANK 247 Chickering Road North Andover, MA Prepared For: Enterprise Bank 222 Merrimack Street Lowell, MA 01852 March 13, 2019 Revised March 25, 2019 Revised April 24, 2019 Prepared By: AM 1-2 MHF Design Consultants, Inc. " o. 73 q ENGINEERS - PLANNERS -SURVEYORS 44 Stiles Road - Suite One - Salem, NH 03079 TEL: (603) 893-0720 - FAX: (603) 893-0733 www.mhfdesign.com TABLE OF CONTENTS Section I — Stormwater Checklist Section 2 - Stormwater Management Narrative Section 3 — Stormwater Management Standards Section 4 - Stormwater Analysis Summary Appendix A—NRCS Soil Report Appendix B —Test Pit Logs Appendix C —Pre-Development Drainage Calculations o HydroCAD printouts Appendix D — Post-Development Drainage Calculations o HydroCAD printouts Appendix E — Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan Appendix F— Illicit Discharge Statement Map Pockets (inside back cover) o Pre-Development Drainage Plan o Post-Development Drainage Plan Under Separate Cover o Operation&Maintenance Plan&Long Term Pollution Prevention Plan for Stormwater Management Systems o Operation&Maintenance Plan Log Forms \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc Section 1 Stormwater Checklist The completed MA DEP Checklist for Stormwater Report is included on the following pages. \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program Checklist Stormwater A. Introduction Important:When A Stormwater Report must be submitted with the Notice of Intent permit application to document filling out forms compliance with the Stormwater Management Standards. The following checklist is NOT a substitute for on the computer, Report(which hih should substantive d detailed information)t St e Stormwater e wc sou provide more sustantve and but is offered use only the tab the p p ) key to move your here as a tool to help the applicant organize their Stormwater Management documentation for their cursor-do not Report and for the reviewer to assess this information in a consistent format. As noted in the Checklist, use the return the Stormwater Report must contain the engineering computations and supporting information set forth in key. 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.' 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. '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. 4570-NOlswcheck-Rev1.doc•04/01/08 Stormwater Report Checklist•Page 1 of 8 LlMassachusetts 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 -7 A �SfGUx _ ti / Z4 l4 Sign ure 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 4570-NOlswcheck-Revl.doc•04/01/08 Stormwater Report Checklist•Page 2 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program Checklistr meport Checklist (continued) LID Measures: Stormwater Standards require LID measures to be considered. Documentwhat environmentally sensitive design and LID Techniques were considered during the planning and design of the project: ® No disturbance to any Wetland Resource Areas ❑ Site Design Practices (e.g. clustered development, reduced frontage setbacks) ® Reduced Impervious Area (Redevelopment Only) ❑ Minimizing disturbance to existing trees and shrubs ❑ LID Site Design Credit Requested: ❑ Credit 1 ❑ Credit 2 ❑ Credit 3 ❑ Use of"country drainage" versus curb and gutter conveyance and pipe ❑ Bioretention Cells (includes Rain Gardens) ❑ Constructed Stormwater Wetlands (includes Gravel Wetlands designs) ® Treebox Filter ❑ Water Quality Swale ❑ Grass Channel ❑ Green Roof ❑ Other(describe): Standard 1: No New Untreated Discharges ® No new untreated discharges ® Outlets have been designed so there is no erosion or scour to wetlands and waters of the Commonwealth ® Supporting calculations specified in Volume 3 of the Massachusetts Stormwater Handbook included. 4570-NOlswcheck-Rev1.doc•04/01/08 Stormwater Report Checklist•Page 3 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program Checklist 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. (See Soils Logs) ® 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 Field' ❑ 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. 21 E 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. 21 E site or a solid waste landfill and a mounding analysis is included. ' 80%TSS removal is required prior to discharge to infiltration BMP if Dynamic Field method is used. 4570-NOlswcheck-Rev1.doc•04/01/08 Stormwater Report Checklist•Page 4 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program Checklist for Sr r 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. 4570-NOlswcheck-Rev1.doc•04/01/08 Stormwater Report Checklist•Page 5 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist Checklist (continued) Standard 4: Water Quality (continued) ® The BMP is sized (and calculations provided) based on: ❑ The '/" 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. 4570-NOlswcheck-Rev1.doc•04/01/08 Stormwater Report Checklist•Page 6 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program Checklist r blormwater 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. 4570-NOlswcheck-Rev1.doc-04/01/08 Stormwater Report Checklist-Page 7 of 8 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist 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. 4570-NOlswcheck-Revl.doc•04/01/08 Stormwater Report Checklist•Page 8 of 8 Section 2 Stormwater Management Narrative Enterprise Bank is proposing to raze the existing 2-story veterinary building and demolish the associated paved parking& site features. The proposal is to redevelop the entire parcel into a new Enterprise Bank facility including a 3,250 square foot, 1-story building with drive-thru along with associated paved driveways,access aisles, 20 striped parking spaces,and a new trash enclosure. Site improvements also include new utility connects to existing services located within Chickering Road as well as a new stormwater management system. The stormwater management practices incorporated into this project includes two(2)new deep sump, hooded catch basins,two(2)Filterra tree box filters as well as a"First Defense"hydrodynamic separator water quality unit.An underground roof infiltration system is proposed in front of the new building.The development plan also proposed a reduction of onsite impervious area from existing conditions which promotes additional groundwater recharge. The design point for the stormwater analysis is the closed drainage system located within Chickering Road. \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc Section 3 Stormwater Management Standards This project;which is considered a redevelopment project,meets the Stormwater Management Standards as outlined in the Massachusetts Stormwater Handbook as follows: Standard 1: No New Untreated Discharges • No new untreated Stormwater discharges are proposed. • Outlets have been designed so there is no erosion or scour in the wetlands or waters of the Commonwealth. • Supporting calculations demonstrating compliance are included. Standard 2: Peak Rate Attenuation • By reducing onsite impervious cover from existing conditions and collecting onsite runoff within the new closed drainage system,the post-development peak discharge rates are less than the pre- development peak discharge rates for the 2, 10 and 100-year storms. Standard 3: Recharge • Onsite groundwater recharge is provided to the maximum extent practicable in accordance with re-development regulations. • Recharge is provided with the use of an underground roof infiltration system consisting of "Stormtech"chambers &stone. Further recharge credit is achieved through the reduction of onsite impervious area with the proposed redevelopment. • GRV Calculation: (0.25"of runoff is required to be recharged for"C"soils) Total proposed onsite impervious area= 17,408 square feet GRV= 17,408SF x(0.25"/12)=363 cubic feet Volume provided within underground infiltration system=363 cubic feet (Calculations demonstrating a 72-hour drawdown time are included on the following pages) Standard 4: TSS Removal • A Long-Term Pollution Prevention Plan that fully meets the requirements of Standard 4 has been developed and is included as an attachment to this report. • Calculations documenting TSS removal for this project are as follows: Drainage Area BMP TSS Removal Rate Driveway/Parking Street Sweeping 5% Driveway/Parking Catch Basin w/sump 25% Driveway/Parking First Defense 75% Driveway/Parking Filterra Tree Box Filter 85% Roof Infiltration System 80% Northern Parking Lot Area: Beginning Load: 1.00 x Street Sweeping removal rate(0.05)=0.05 Load Remaining = 1.00—0.05 =0.95 Remaining Load: 0.95 x Catch Basin w/sump removal rate(0.25)=0.24 Load Remaining =0.95 —0.24 =0.71 Remaining Load: 0.71 x First Defense removal rate(0.75)=0.53 \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc Load Remaining =0.71 —0.53 =0.18 Total TSS Removal Rate=(1.00—0.18)=82% Southern Parking Lot Area: Beginning Load: 1.00 x Street Sweeping removal rate (0.05)=0.05 Load Remaining = 1.00—0.05 =0.95 Remaining Load: 0.95 x Filterra removal rate(0.85)=0.81 Load Remaining =0.95—0.81 =0.14 Remaining Load: 0.14 x First Defense removal rate(0.75)=0.11 Load Remaining =0.14—0.11 =0.03 Total TSS Removal Rate=(1.00—0.03)=97% Calculations: Water Ouality Volume Total Site Area (Non-LUHPPL): Existing onsite impervious area=21,793 sf Proposed onsite impervious area= 17,098 sf Net decrease in impervious area=21,793 sf— 17,098 sf=4,695 sf WQV =0.5"x Impervious Area = 0.5"x 1 ft/ 12"x 17,098 sf=712 c.f. Provided=363 c.f. (Static Storage within UG Infiltration System)—See Attached Stage-Storage Table. Note: Only the UG Infiltration System is a volume-based treatment practice. The Filterra units are flow based. Calculations demonstrating treatment of a'/Z " event for the Filterra units are included on the following pages. Standard 5: Land Uses with Higher Potential Pollutant Loads + The site does not contain any land uses with higher potential pollutant loads (see detailed description of proposed facility on the following pages). Standard 6: Critical Areas • The project is not near any critical areas. Standard 7: Redevelopments and Other Projects Subject to the Standards only to the maximum extent practicable • This is a redevelopment project and is the project subject to the Stormwater Management Standards to the maximum extent practicable. Standard 8: Construction Period Pollution Prevention and Erosion and Sediment Control • A Construction Period Pollution Prevention and Erosion and Sediment Control Plan is included in this report in Appendix E. Standard 9: Operation and Maintenance Plan • A long term operation and maintenance plan meeting the requirements of this standard has been prepared and is included as a separate document attached to this report. \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc Standard 10: Prohibition of Illicit Discharges: ® To the best of our knowledge,the site does not contain any illicit discharges(see attached Illicit Discharge Statement in Appendix F). \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc MHF Project No. 457019 Sheet 1 of 1 ® ' Project Description Enterprise Bank-North Andover,MA Task Pond Drawdown Calculations I'lIF Design Consultants, Inc. Calculated By CMT Date 0424/19 Checked By Date ENGINEERS • PLANNERS • SURVEYORS Drawdown within 72 hours Analysis for Static Method Roof Infiltration System Infiltration Rate: 1.02 inches/hour(From table 2.3.3: Rawls, Brakensiek, Saxton, 1982) Design Infiltration Rate: 1.02 inches/hour Volume Provide for Infiltration: 363 cf (Volume provided up to 12"overflow outlet at elev. 194.15) Basin bottom area: 433 sf Time drawdown= (Required Recharge Volume in cubic feet as determined by the Static Method)(1/Design Infiltration Rate in inches per hour)(conversion for inches to feet)(1/bottom area in feet) Time drawdown = ( 363 cf) ( 1 / 1.02 in/hr) (1ft/12 in.) ( 1 / 433 sf) 9.86 hours 457019-24-hr Pond Drain Calcs.xis Calculation of Required Water Quality Flow for Sizing of Stormwater Treatment System 4/24/2019 Based on Massachusetts DEP document: "Standard Method to Convert Required Water Quality Volume to a Discharge Rate for Sizing Flow Based Manufactured Proprietary Stormwater Treatment Practices" Stormwater Standard No.4 requires that the full WQV be captured and treated to remove 80%of the average annual post-construction TSS load. Since manufactured proprietary separators are sized using discharge rates and not volume,MassDEP is requiring this standard method be used to convert the required WQV to a discharge rate(WQF)to be treated. Project Site: North Andover Bank Project Location: North Andover,MA Runoff Depth,Q: 1 " (0.5"or 1") Table 1. Structure Area YO Name (acres) Impervious A(miles) tc(min.) tc(hrs.) DMH-1 0.54 72.23% 0.000609 6.00 0.100 Because only runoff from impervious surfaces is used in calculation of WQV,area is considered 100%impervious Therefore,CN= 98 Enter la/P Ratio for CN=98: la/P= 0.034 (0.058 for Q=0.5"/0.034 for Q=1") Enter unit peak discharge,qu(csm/in)for Type III rainfall distribution,la/P,and tc: From Figure 2(Q=0.5")or Figure 4(Q=1") Table 2. Structure Name tc(hours) qu(csm/in) DMH-1 0.100 774 WQF in cfs=(gu)(A)(Q),where: WQF=water quality flow(cfs) q"=unit peak discharge(csm/in) From Table 2 above A=drainage area(mil) From Table 1 above Q=runoff depth(watershed inches) Based on Area Type,from above Table 3. Structure q„ A Q WQF Proposed Name (csm/in) (miles) (in) (cfs) Device DMH-1 774 0.000609 1 0.47 FD-4HC 1Proposed Device is sized so that the required site WQF is less than the treatment flow at which the device achieves at least 80%TSS removal,as documented by enclosed test data. Hy0ro International First ° High A Simple Solution for your Trickiest Sites Verified by NJCAT and NJDEP Fig.1 The First Defense®High Capacity has internal components Product Profile designed to efficiently capture pollutants and prevent washout at peak flows. The First Defense®High Capacity is an enhanced vortex separator 1 1r that combines an effective stormwater treatment chamber with an integral peak flow bypass. It efficiently removes sediment total suspended solids(TSS),trash and hydrocarbons from stormwater runoff without washing out previously captured pollutants.The First �� --6 Defense®High Capacity is available in several model configurations 2 to accommodate a wide range of pipe sizes, peak flows and depth constraints(Table 1, next page). Applications 3 —7 • Stormwater treatment at the point of entry into the drainage line •Sites constrained by space,topography or drainage profiles 4 with limited slope and depth of cover � � i� 8 • Retrofit installations where stormwater treatment is placed on or u — tied into an existing storm drain line • Pretreatment for filters, infiltration and storage 5 9 Advantages • Inlet options include surface grate or multiple inlet pipes • Integral high capacity bypass conveys large peak flows without --- 10 the need for"offiine"arrangements using separate junction manholes Components • Proven to prevent pollutant washout at up to 450%of its treatment flow 1. Inlet Grate(optional) 6. Internal Bypass •Long flow path through the device ensures a long residence 2. Precast chamber 7. Outlet pipe time within the treatment chamber, enhancing pollutant settling 3. Inlet Pipe(optional) 8. Oil and Floatables Storage • Delivered to site pre-assembled and ready for installation 4. Floatables Draw Off Slot 9. Outlet chute (not pictured) 10. Sediment Storage Sump HOW it Works 5. Inlet Chute The First Defense® High Capacity has internal components designed to remove and retain gross debris, total suspended solids (TSS) ani hydrocarbons(Fig.1). Contaminated stormwater runoff enters the inlet chute from a surface grate and/or inlet pipe. The inlet chute introduces flow into the chambe tangentially to create a low energy vortex flow regime (magenta arrow)that directs sediment into the sump while oils, floating trash and debri rise to the surface. Treated stormwater exits through a submerged outlet chute located opposite to the direction of the rotating flow(blue arrow). Enhanced vorte. separation is provided by forcing the rotating flow within the vessel to follow the longest path possible rather than directly from inlet to outlet. Higher flows bypass the treatment chamber to prevent turbulence and washout of captured pollutants.An internal bypass conveys infrequer peak flows directly to the outlet eliminating the need for, and expense of, external bypass control structures. A floatables draw off slot function to convey floatables into the treatment chamber prior to bypass. Hydro International,94 Hutchins Drive,Portland,ME 04102 Tel:(207)756-6200 Fax:(207)756-6212 Stormwater Solutions Email:stormwaterinquiry@hydro-int.com Web:www.hydro-int.com hvdro-int.com/firstdefensehc First D fe & High _Capacity Sizing & Design SIZING CALCULATOR FOR ENGINEERS This adaptable online treatment system works easily with large pipeo, multiple inlet pipes, inlet grates and now, contains high capacity bypass for the conveyance of large peak flows. Designed with site flexibility in mind, the First Defense8 High Capacity allows engineers to maximize available site space without compromising treatment level. Variable inlet an les This simple online tool will recommend the best separator, model size and on|ino6offlinnarrangement based on site-specific data entered by the user. Go to to access the tool. Fig 2.Works with multiple inlet pipes and grates Inspection and Maintenance Nobody maintains our systems better than wm do. To ensure optimal, ongoing device performance, be sure to recommend Hydro International aoapreferred service and maintenance provider ho your clients. Table 1. First Criteria. Fig 3.Maintenance io done with avodnrtruck 'Contact Hydro,International when larger pipe sizes are required. 2Contact Hydro,Internationalwhen custom sediment storage capacity iorequired. 'Minimum distance for models depends un pipe diameter. Hydro International,84 Hutchins Drive, Purt|ond,MEO41O2 StormwatarSo|uUons Tel:(nOr)75O'O2O0 Fax:(2O7)750'8212 HIL 0 ro Technical Abstract International First ��~~�~� ^�V� High Capacity U�K� �� U�� U�� — � �� ~~ — K—� � � ��v�� *�� xo �� n n�� m�� u ~� N|CAT Verified Performance Testing — OK110 /[l50 = 108 U0O\ Particle Sizes Rq[lOe Introduction -------�---------- -----------'--- The inbema| oompona�oomdesigned bo@i�o�andavdpmoont Hydm|nbama�ona|h000a��'o��e-o�hydnyu|ioeundh»�tooi|ity manholes and are installed hu collect runoff oa part of typical drain- that iouoodbothhodovn|oppmductoandtoovo|uotoparfonnanne. age network ayatom Duhngaminovont flow enters e�hnr�oma Through controlled testing using induatryotondandtontpmt000|o. ' au�oon inlet grate or inlet pipe.�u�mwonhamtho manhole, oom- Hydm'aimotmentpmdudoareova|uatodundnrvaryinghydnou|io � ' pononto divert flow and pollutants into o Vortex Chamber beneath and sediment load conditionoVViMhaknowndnoinageareaorwmhar� aoeponotionmodule, that includes both|n|e8DuUot Chutes and By- quality flow noto' these test naou|tn are used to benchmark treat- pass Weirs. The internal Bypass Weirs divert peak flows over the ment objectives and bu select the correct model size. separation module and away from the Vortex Chamber where po|' Aunmmonotonnwmtortnaatmentgna|furmonufaotunadtmatm*nt lutants are collecting. This prevents high velocities from re-sus- devices is to reduce the Total Suspended Solids(TSS)concentra- Pending captured pollutants during infrequent but large nhonn tion byat least 8U%. To comply with this goa|, a silica-based toot events. sand with known particle size gradation (PSO) end density is in' Capable of p j*�ed into the treatment system at different flow rates.VVdh known flow high pollutant removals for a wide range of flowmtea and pipe sizes, the FDHC can be installed ether online TSS concentrations and particle oio*n before and after treatment, ' or ��ino depending on pipes and peak flows. Its efficiency and effioiennyoumoaomp|o�odonduoodtnpnadiotTSSmduntionofor � simplicity make it economical ho install and maintain. a range uf particle sizes. U.S. Silica OK11Oiea common test sand that has been used by Laboratory Testing Arrangement the industry but is no longer available. However, its PSD can be The laboratory setup (Figure 2)cnnx|��oU of mo|mu|aUng n|oonu replicated from o blend nf silica sands having a wide range ofpar- loop system with on8-inoh (2OOmm)submersible F|ygt pump that Uc|e sizes.This abstract summarizes test results based onaporh' conveyed water from o23.UOU gal (87.U04L) reservoir through o u|e size range similar&oOK11O for the First Defeno*O High Copan' PVC pipe network 0o the 4-ft (12m) FDHC. The flow rate ofthe ity(FDHC).All test protocols and results have been independently pump was controlled byaGE Fuji Electric AF'3OOP11Adjustable verified by the New Jersey Corporation for Advanced Technology Frequency Drive and measured byanEk4CO Flow Systems 4411* Bo��mmognetioFlow TmnomiUor.Test sand was irjo�edinto the (NJCAT)� incoming flow stream using o volumetric screw feeder situated 1O' CapacityFirst Defense High ft prior 0o entering the test unit. /nvrunu(Figure //has patented flow modifying internal vumpu- =°fcn."~. nanto that create a gentle swirling flow path within the Vortex Effluent Sample Other MID Chamber. The rotating flow creates low energy vortex forces that supplement gravitational settling fovoaa to enhance separation of pollutants. ffi Poll Sediment feed Poll Pipe Pump Bypass Weirs .""."°MID Outlet � Inlet Chute Pipe Outlet Figure 3-Set-up of the Portland,Maine hydraulic testing facility Vortex Chamber Chute Test Sediment "k, The feed sediment injected into the inlet during removal efficiency Sediment orage testing was o blend of commercially available silica sands ranging Sump from 2pmtu1.UOO pm.The PSDuf the test sediment was analyzed ` byon independent laboratory in accordance with AGTN1D422'63. To evaluate the performance of the tested FDHC model for a par- Figure 1 First Defense High C ity ticle size band similar to OKI 10, results were analyzed from the First efense° - High Capacity particle sizes range of 50 pm to 150 pm (D5o=108pm).A compari- The average effluent sediment concentration of the three compo- son of the two gradations is shown in Figure 3, which shows the sited samples was also measured for each flow rate in accord- test sand gradation to be slightly finer than OK110 between 50pm ance with ASTM D3977-97.The effluent concentration for each and 1 OOpm. For example, the test sand had 15%finer than 75 mi- particle size band was then calculated using the average effluent crons compared to the OK110 PSD that had only 3% less than 75 composite concentration and percentage of particles in each parti- microns. Given finer particles are more difficult to settle, perfor- cle size band. mance results based on the"OK110" particle size band of the test sand is considered conservative. Percent removed at each of the five tested flow rates is shown in Table 1. Inlet concentrations of the OK110 particle size range var- 100% ied from 79-84 mg/L compared to 4-8.5 mg/L at the outlet.As ex- 90% pected,the highest concentration measured at the outlet was at the highest tested flow rate of 1.88 cfs (53.2 Us). In general, the 4-ft 80% FDHC removed greater than 80%of the OK110 particle size range m 70% for all tested flow rates. Table 2 provides "Treatment Flow Rates" LL 60% j -- for the available models. m 50% _ i 40% Table 2—FDHC Treatment Flow Rate for>80%TSS a 30% I 20% 10% 0% - cfs: 1.06 1.88 2.94 4.23 10 100 1,000 29 53 83 19 2712. US:Particle Size(microns) —Test Sand —0—OK110 Figure 3-Particle Size Distribution Comparison Removal Efficiency Testing_ Removal efficiency testing with the feed sediment was conducted in accordance with Section 5 of the NJDEP Laboratory Protocol for Manufactured Treatment Devices. Five flow rates ranging from: 25%to 125%of the design treatment flow rate were evaluated. �„plr9il"71 The test sediment was fed into the flow stream at a rate that was equivalent to 200 mg/L.The average influent TSS concentration was calculated using the total sediment mass and volume of wa- ter added during dosing.The influent concentration for each parti- cle size band was calculated using the percentage of particles in each particle size band and known average inlet concentration. Three time-spaced effluent grab samples were composited and analyzed using laser diffraction(ISO 13320)to evaluate the efflu- ent particle sizes. _ Table 1—OK110 Particle Size Range Test Results N • . 0.38 84 4.44 95 (10.8) For design purposes the selected model's Treatment Flow Rate 0.75 83 5.50 93 must be equal or greater to the site's required Water Quality Flow (21.2) Rate.The peak flow rate and maximum pipe size must be consid- 1.13 78 4.00 95 ered to determine whether an online or offline configuration is ap- 32.0 propriate. Full removal curves are available on request. 1.5 1.5 83 6.57 92 1.88 Refer First Defense product information brochure or visit www.hy- 53.2 79 8.81 89 dro-int.com/us for more information Hydro International.94 Hutchins Drive. Portland.ME 04102 Stormwater Solutions Tel:207.756.6200 Fax:207.756.6212 ©Hydro International FDHC TA_DownTo_D1702 Email:stormwateringuiryCa7hydro-int.com Web:www.hydro-int.com 4570-Postdrain-Revl Type ///24-hr 100-year Rainfall=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Stage-Area-Storage for Pond INFIL: U/G INFIL Elevation Surface Storage (feet) (sq-ft) (cubic-feet) 192.00 433 0 192.05 433 9 192.10 433 17 192.15 433 26 192.20 433 35 192.25 433 43 192.30 433 52 192.35 433 61 192.40 433 69 192.45 433 78 192.50 433 87 192.55 433 102 192.60 433 118 192.65 433 134 192.70 433 150 192.75 433 165 192.80 433 181 192.85 433 196 192.90 433 211 192.95 433 226 193.00 433 240 193.05 433 255 193.10 433 269 193.15 433 284 193.20 433 297 193.25 433 311 193.30 433 325 193.35 433 338 193.40 433 351 193.45 433 363 O 193.50 433 375 193.55 433 386 VMOKC 193.60 433 397 193.65 433 408 193.70 433 417 193.75 433 427 193.80 433 436 193.85 433 444 193.90 433 453 193.95 433 462 194.00 433 470 194.05 433 479 194.10 433 488 194.15 433 496 194.20 433 505 194.25 433 514 194.30 433 522 Section 4 Stormwater Analysis Summary Project Description Enterprise Bank is proposing to raze the existing 2-story veterinary building and demolish the associated paved parking&site features. The proposal is to redevelop the entire parcel into a new Enterprise Bank facility including a 3,250 square foot, 1-story building with drive-thru along with associated paved driveways, access aisles,20 striped parking spaces, and a new trash enclosure. Site improvements also include new utility connects to existing services located within Chickering Road as well as a new stormwater management system. The purpose of this report is to determine the pre-and post-development rates of stormwater runoff generated by this project and the impact of that runoff on downstream receiving waters and the surrounding properties. Existing Conditions The site is currently fully developed and has been the site of a veterinary business. The existing development consists of a 7,561 square foot,2-story building with associated driveways, access aisles, and paved parking for 32 striped spaces. Most of the parcel is paved with the exception of some small landscape strips along the outer limits. The property is bordered by the"99 Restaurant"property to the north and east,by residential properties to the south, and by Chickering Road to the west. There is a wetland resource area located on the adjacent property to the south. The existing developed parcel slopes from rear to front(east to west)with roughly 4 feet of elevation change. The site is situated slightly higher than the abutting restaurant parking lot,with landscaped slopes transitioning between the two developments. There are currently no stormwater management practices in-place for the existing development. Onsite runoff currently sheet flows out of the two site driveways and into Chickering Road. The on-site soils consist primarily of Woodbridge fine sandy loam (310A). Additional information regarding this soil group and the adjacent soils can be found in Appendix A. Soil test pits were performed onsite. The test pit logs are included in Appendix B. Proposed Conditions The stormwater management practices incorporated into this project includes two (2)new deep sump, hooded catch basins,two (2)Filterra tree box filters as well as a"First Defense"hydrodynamic separator water quality unit.An underground roof infiltration system is proposed in front of the new building. The development plan also proposed a reduction of onsite impervious area from existing conditions which promotes additional groundwater recharge. By reducing onsite impervious cover from existing conditions and collecting onsite runoff within the new closed drainage system the post-development peak discharge rates are less than the pre-development peak discharge rates for the 2, 10 and 100-year storms. \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc Methodology The drainage system for this project was modeled using HydroCAD, a Computer Aided Design system for modeling the hydrology and hydraulics of stormwater runoff. It is based largely on the hydrology techniques developed by the Soil Conservation Service(SCSINRCS), combined with other hydrology and hydraulics calculations. For a given rainfall event,these techniques are used to generate hydrographs throughout a watershed. This program can be used verify that a given drainage system is adequate for the area under consideration, or to predict where flooding or erosion is likely to occur. In HydroCAD, each watershed is modeled as a subcatchment, streams and culverts as reaches and ponds, large wetlands and storage areas as ponds. SCS hydrograph and routing stormwater models were used for both Pre-Development conditions and Post-Development conditions. The Pre-Development and Post-Development watershed limit and sub-area characteristics were determined using actual ground survey, and through visual inspection of runoff paths by walking the site. Conservative estimates were used in evaluating the hydrologic characteristics of the watershed. For the purpose of quantifying the Pre-and Post-Development runoff rates and volumes the project site was analyzed the closed drainage system located within Chickering Road as the design point. The results of the Pre-and Post-Development analysis are as follows: HydroCAD Analysis Summary Design Storm Pre-Development Post-Development Change (peak runoff rate (peak runoff rate DESIGN POINT#1 Chickerin Rd/Rte 125 2-year 2.1 1.6 -0.5 10- ear 3.4 3.1 -0.3 100- ear 6.5 6.1 -0.4 (All values shown are peak rates in CFS,cubic feet per second) These results indicate that the on-site stormwater BMP's will reduce the Post-Development peak flow rates below the Pre-Development peak flow rates for the 2, 10 and 100-year storms. As a result,there will be no adverse impact to the receiving waters or downstream properties. \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc Appendix A NRCS Soils Report \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc USDA United States A product of the National Custom Soil Resource Department of Cooperative Soil Survey, Agriculture a joint effort of the United Report for States Department of NRCS Agriculture and other Essex County' Federal agencies, State Natural agencies including the Massachusetts, Resources Agricultural Experiment Conservation Stations, and local Service participants Northern Part 0 8,000 ft February 26, 2019 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.nres.usda.gov/wps/ portal/nres/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=nres)or your NRCS State Soil Scientist(http://www.nres.usda.gov/wps/portal/nres/detail/soils/contactus/? cid=nres142p2_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 HowSoil Surveys Are Made..................................................................................5 SoilMap.................................................................................................................. 8 SoilMap................................................................................................................9 Legend................................................................................................................10 MapUnit Legend................................................................................................ 11 MapUnit Descriptions.........................................................................................11 Essex County, Massachusetts, Northern Part................................................ 13 310A—Woodbridge fine sandy loam, 0 to 3 percent slopes....................... 13 Soil Information for All Uses...............................................................................15 Soil Properties and Qualities.............................................................................. 15 Soil Qualities and Features.............................................................................15 HydrologicSoil Group................................................................................. 15 References............................................................................................................20 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 Custom Soil Resource Report 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 6 Custom Soil Resource Report identified each as a specific map unit. Aerial photographs show trees, buildings, fields, roads, and rivers, all of which help in locating boundaries accurately. 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 Custom Soil Resource Report 3 Soil Map 3 a F r` n n 32610D 325110 32612D 325130 326140 326150 326160 326170 326180 325190 326M 326210 326220 326MO 326240 326250 326290 42°41'9"N � �� I 88 42°41'9"N o_ \�~ 8 i Q a 42°41'6"N _ 42°41'6"N 326090 32610D 325110 326120 325130 326140 326150 328160 326170 326180 325190 3252DO 326210 32622D 326230 326240 326250 325260 3 3 `a Map Scale:1:809 if printed on A landscape(W x 8S')sheet F N Nklars ° n0 10 20 40 60 n /V 0 35 70 140 210 Map pmjecbon:Web Mertata Gomerooadinat s:WGS84 Edge tics:UfM Zam 19N WG584 9 Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest(AOI) Spoil Area The soil surveys that comprise your AOI were mapped at Area of Interest(AOI) 1:15,800. �t Stony Spot Soils sj Very Stony Spot 0 Soil Map Unit Polygons Warning:Soil Map may not be valid at this scale. Wet Spot Soil Map Unit Lines Enlargement of maps beyond the scale of mapping can cause Soil Map Unit Points Other misunderstanding of the detail of mapping and accuracy of soil ,- Special Line Features line placement.The maps do not show the small areas of Special Point Features contrasting soils that could have been shown at a more detailed Ua Blowout Water Features scale. Streams and Canals Borrow Pit Transportation Please rely on the bar scale on each map sheet for map Clay Spot +44 Rails measurements. Closed Depression �+ Interstate Highways Source of Map: Natural Resources Conservation Service Gravel Pit US Routes Web Soil Survey URL: Gravelly Spot Major Roads Coordinate System: Web Mercator(EPSG:3857) Landfill Local Roads Maps from the Web Soil Survey are based on the Web Mercator JL Lava Flow Background projection,which preserves direction and shape but distorts distance and area.A projection that preserves area,such as the Marsh or swamp ImAerial Photography Albers equal-area conic projection,should be used if more Mine or Quarry accurate calculations of distance or area are required. Q Miscellaneous Water This product is generated from the USDA-MRCS certified data as Perennial Water of the version date(s)listed below. er. Rock Outcrop Soil Survey Area: Essex County,Massachusetts,Northern Part + Saline Spot Survey Area Data: Version 14,Sep 7,2018 a sandy spot Soil map units are labeled(as space allows)for map scales Severely Eroded Spot 1:50,000 or larger. Sinkhole Date(s)aerial images were photographed: Aug 29,2014—Sep Slide or Slip 19,2014 oa Sodic Spot The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps.As a result,some minor shifting of map unit boundaries may be evident. 10 Custom Soil Resource Report Map Unit Legend Map Unit Symbol Map Unit Name Acres in A01 Percent of A01 1310A Woodbridge fine sandy loam,0 1.6 100.0% to 3 percent slopes Totals for Area of Interest 1.6 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. 11 Custom Soil Resource Report 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. 12 Custom Soil Resource Report Essex County, Massachusetts, Northern Part 310A—Woodbridge fine sandy loam, 0 to 3 percent slopes Map Unit Setting National map unit symbol: 2w686 Elevation: 0 to 1,420 feet Mean annual precipitation: 36 to 71 inches Mean annual air temperature: 39 to 55 degrees F Frost-free period: 140 to 240 days Farmland classification: All areas are prime farmland Map Unit Composition Woodbridge and similar soils: 85 percent Minor components: 15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Woodbridge Setting Landform: Drumlins, hills, ground moraines Landform position (two-dimensional): Footslope, summit Landform position (three-dimensional): Crest Down-slope shape: Convex Across-slope shape: Linear Parent material: Coarse-loamy lodgment till derived from gneiss, granite,and/or schist Typical profile Ap-0 to 7 inches: fine sandy loam Bw1 - 7 to 18 inches: fine sandy loam Bw2- 18 to 30 inches: fine sandy loam Cd-30 to 65 inches: gravelly fine sandy loam Properties and qualities Slope: 0 to 3 percent Depth to restrictive feature: 20 to 39 inches to densic material Natural drainage class: Moderately well drained Runoff class: Very high Capacity of the most limiting layer to transmit water(Ksat): Very low to moderately low(0.00 to 0.14 in/hr) Depth to water table: About 18 to 30 inches Frequency of flooding: None Frequency of ponding: None Salinity, maximum in profile: Nonsaline (0.0 to 1.9 mmhos/cm) Available water storage in profile: Low (about 4.7 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2w Hydrologic Soil Group: C/D Hydric soil rating: No 13 Custom Soil Resource Report Minor Components Paxton Percent of map unit: 7 percent Landform: Hills, ground moraines, drumlins Landform position (two-dimensional): Summit, shoulder Landform position (three-dimensional): Crest Down-slope shape: Linear, convex Across-slope shape: Convex Hydric soil rating: No Ridgebury Percent of map unit: 6 percent Landform: Ground moraines, depressions, hills, drumlins, drainageways Landform position (two-dimensional): Toeslope,footslope Landform position (three-dimensional): Base slope, head slope Down-slope shape: Concave Across-slope shape: Concave Hydric soil rating: Yes Whitman, extremely stony Percent of map unit: 1 percent Landform: Drainageways, depressions Down-slope shape: Concave Across-slope shape: Concave Hydric soil rating: Yes Sutton Percent of map unit: 1 percent Landform: Ground moraines, hills Landform position (two-dimensional): Footslope Landform position (three-dimensional): Base slope Down-slope shape: Concave Across-slope shape: Linear Hydric soil rating: No 14 Soil Information for All Uses Soil Properties and Qualities The Soil Properties and Qualities section includes various soil properties and qualities displayed as thematic maps with a summary table for the soil map units in the selected area of interest. A single value or rating for each map unit is generated by aggregating the interpretive ratings of individual map unit components. This aggregation process is defined for each property or quality. Soil Qualities and Features Soil qualities are behavior and performance attributes that are not directly measured, but are inferred from observations of dynamic conditions and from soil properties. Example soil qualities include natural drainage, and frost action. Soil features are attributes that are not directly part of the soil. Example soil features include slope and depth to restrictive layer. These features can greatly impact the use and management of the soil. Hydrologic Soil Group Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential)when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. 15 Custom Soil Resource Report Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential)when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. 16 Custom Soil Resource Report Map—Hydrologic Soil Group p F F n � 326100 326110 M120 325130 326140 M150 M160 325170 326180 326190 32M 326210 326120 326230 326240 326250 326260 4r 41'9"N 'i I° 8 42 41 5 N i 8 \ a, \ i� `r o o � v _8 8 v c c v v v v v v v a 1, 42°41'6 N v 42"41'6"N 325= 328100 325110 325120 325130 325140 326150 326160 326170 326180 326190 325200 326210 32a"220 326230 326240 326250 326260 3 3 F Map Scale:1:809 if prinbed on A landscape(11"x 8.5')sheet F Mebers N 0 10 20 40 60 AFeEt 0 o a5 � ,4o z,o �p prof:Web Mercator Comer coordinates:WGSM Edge tics:UTM Zone 19N WGSN 17 Custom Soil Resource Report MAP LEGEND MAP INFORMATION Area of Interest(Aoq Ell C The soil surveys that comprise your AOI were mapped at Area of Interest(AOI) Ell C/D 1:15,800. Soils 13 D Soil Rating Polygons Warning:Soil Map may not be valid at this scale. 0 A ® Not rated or not available Enlargement of maps beyond the scale of mapping can cause Water Features 0 AID misunderstanding of the detail of mapping and accuracy of soil B Streams and Canals line placement.The maps do not show the small areas of Transportation contrasting soils that could have been shown at a more detailed 0 B/D + 4 Rails scale. 0 Ce Interstate Highways Please rely on the bar scale on each map sheet for map C/D US Routes measurements. 0 D Major Roads Source of Map: Natural Resources Conservation Service 0 Not rated or not available Local Roads Web Soil Survey URL: Soil Rating Lines Background Coordinate System: Web Mercator(EPSG:3857) " AImAerial Photography Maps from the Web Soil Survey are based on the Web Mercator A/D projection,which preserves direction and shape but distorts B distance and area.A projection that preserves area,such as the Albers equal-area conic projection,should be used if more B/D accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as C/o of the version date(s)listed below. r D Soil Survey Area: Essex County,Massachusetts,Northern Part r M Not rated or not available Survey Area Data: Version 14,Sep 7,2018 Soil Rating Points A Soil map units are labeled(as space allows)for map scales - - 1:50,000 or larger. a A/D ® B Date(s)aerial images were photographed: Aug 29,2014—Sep 19,2014 B/D The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps.As a result,some minor shifting of map unit boundaries may be evident. 18 Custom Soil Resource Report Table—Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 1 310A Woodbridge fine sandy C/D 1.6 100.0% loam,0 to 3 percent slopes Totals for Area of Interest 1.6 100.0% Rating Options—Hydrologic Soil Group Aggregation Method: Dominant Condition Component Percent Cutoff.None Specified Tie-break Rule: Higher 19 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.nres.usda.gov/wps/portal/ nres/detail/national/soils/?cid=nres142p2_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.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nresl42p2_053577 Soil Survey Staff. 2010. Keys to soil taxonomy. 11th edition. U.S. Department of Agriculture, Natural Resources Conservation Service. http:// www.nres.usda.gov/wps/portal/nres/detail/national/soils/?cid=nresl42p2_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.nres.usda.gov/wps/portal/nres/detail/soils/ home/?cid=nres142p2_053374 United States Department of Agriculture, Natural Resources Conservation Service. National range and pasture handbook. http://www.nres.usda.gov/wps/portal/nres/ d eta il/nation al/la nd use/rang epasture/?cid=stelprdb1043084 20 Custom Soil Resource Report United States Department of Agriculture, Natural Resources Conservation Service. National soil survey handbook, title 430-VI. http://www.nres.usda.gov/wps/portal/ nres/detail/soils/scientists/?cid=nres142p2_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.nres.usda.gov/wps/portal/nres/detail/national/soils/? cid=nres142p2_053624 United States Department of Agriculture, Soil Conservation Service. 1961. Land capability classification. U.S. Department of Agriculture Handbook 210. http:H www.nres.usda.gov/lnternet/FSE_DOCUMENTS/nresl42p2_052290.pdf 21 Appendix B Test Pit Logs \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc _ 44 Stiles Road Suite One ® Salem, New Hampshire 03079 TEL (603) 893-0720 ® FAX(603) 893-0733 MHF Design Consultants, Inc. www.mhfdesign.com TEST PIT DATA Client: Enterprise Bank Project Address: 247 Chickering Road Town,State: North Andover,MA Job Number: 457019 Date: March 13,2019 Performed by: Diane Pantermoller(SE#1835) Test Pit No. 1 SCS Soil: Woodbridge ESHWT: 72" Standing Water: None Refusal: >96" Roots: None Depth Horizon Soil Texture Color Consistence Mottles; Quantity/Contrast 0-48" Fill Mixed Soils 48-56" A Loamy Sand l0yr 3/2 FR 56-96" C Loamy Sand 2.5y 6/4 FR @ 72"Distinct Test Pit No. 2 SCS Soil: Woodbridge ESHWT: 72" Standing Water: 72" Refusal: >78" Roots: None Depth Horizon Soil Texture Color Consistence Mottles; Quantity/Contrast 0-48" Fill Mixed Soils 48-56" A Loamy Sand 10yr 3/2 FR 56-78" C Loamy Sand 2.5y 6/4 FR @ 72"Distinct F:\Projects\Test Pit Logs\Massachusetts\457019\Test Pit Logs.docx Page 1 of 1 Appendix C Pre-Development Drainage Calculations \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc is RUNOFF TO ROUTE 125 SubCat Reach Pon Link Routing Diagram for 4570-Predrain-Rev1 Prepared by Microsoft, Printed 4/24/2019 HydroCAD®10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC 4570-Predrain-Reel Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10.00-20 s/n 01710 OU 2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (sq-ft) (subcatchment-numbers) 5,480 74 >75% Grass cover, Good, HSG C (1S) 19,959 98 Paved parking, HSG C (1S) 7,561 98 Roofs, HSG C (1S) 33,000 94 TOTAL AREA 4570-Predrain-Revl Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 3 Soil Listing (all nodes) Area Soil Subcatchment (sq-ft) Group Numbers 0 HSG A 0 HSG B 33,000 HSG C 1S 0 HSG D 0 Other 33,000 TOTAL AREA 4570-Predrain-Rev1 Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 4 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) Cover 0 0 5,480 0 0 5,480 >75% Grass cover, Good 0 0 19,959 0 0 19,959 Paved parking 0 0 7,561 0 0 7,561 Roofs 0 0 33,000 0 0 33,000 TOTAL AREA 4570-Predrain-Reel Type 11124-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10 00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 5 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: RUNOFF TO ROUTE 125Runoff Area=33,000 sf 83.39% Impervious Runoff Depth=2.48" Flow Length=310' Tc=6.0 min CN=94 Runoff=2.11 cfs 6,809 cf Total Runoff Area = 33,000 sf Runoff Volume= 6,809 cf Average Runoff Depth =2.48" 16.61% Pervious =5,480 sf 83.39% Impervious=27,520 sf 4570-Predrain-Rev1 Type/1/24-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 1S: RUNOFF TO ROUTE 125 Runoff = 2.11 cfs @ 12.08 hrs, Volume= 6,809 cf, Depth= 2.48" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-year Rainfall=3.13" Area (sf) CN Description 5,480 74 >75% Grass cover, Good, HSG C 7,561 98 Roofs, HSG C 19,959 98 Paved parking, HSG C 33,000 94 Weighted Average 5,480 16.61% Pervious Area 27,520 83.39% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.6 10 0.0200 0.11 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.8 130 0.0200 2.87 Shallow Concentrated Flow, Paved Kv= 20.3 fps 1.2 170 0.0140 2.40 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.6 310 Total, Increased to minimum Tc = 6.0 min 4570-Predrain-Rev1 Type 111 24-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 7 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: RUNOFF TO ROUTE 125Runoff Area=33,000 sf 83.39% Impervious Runoff Depth=4.10" Flow Length=310' Tc=6.0 min CN=94 Runoff=3.40 cfs 11,277 cf Total Runoff Area= 33,000 sf Runoff Volume= 11,277 cf Average Runoff Depth =4.10" 16.61% Pervious =5,480 sf 83.39% Impervious=27,520 sf 4570-Predrain-Rev1 Type 111 24-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroCADS 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 1S: RUNOFF TO ROUTE 125 Runoff = 3.40 cfs @ 12.08 hrs, Volume= 11,277 cf, Depth= 4.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-year Rainfall=4.79" Area (sf) CN Description 5,480 74 >75% Grass cover, Good, HSG C 7,561 98 Roofs, HSG C 19,959 98 Paved parking, HSG C 33,000 94 Weighted Average 5,480 16.61% Pervious Area 27,520 83.39% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.6 10 0.0200 0.11 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.8 130 0.0200 2.87 Shallow Concentrated Flow, Paved Kv= 20.3 fps 1.2 170 0.0140 2.40 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.6 310 Total, Increased to minimum Tc = 6.0 min 4570-Predrain-Revl Type ///24-hr 100-year Rainfall=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 9 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: RUNOFF TO ROUTE 125Runoff Area=33,000 sf 83.39% Impervious Runoff Depth=8.10" Flow Length=310' Tc=6.0 min CN=94 Runoff=6.46 cfs 22,269 cf Total Runoff Area=33,000 sf Runoff Volume= 22,269 cf Average Runoff Depth =8.10" 16.61% Pervious=5,480 sf 83.39% Impervious=27,520 sf 4570-Predrain-Rev1 Type III 24-hr 100-year Rainfall=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment 1S: RUNOFF TO ROUTE 125 Runoff = 6.46 cfs @ 12.08 hrs, Volume= 22,269 cf, Depth= 8.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-year Rainfall=8.82" Area (sf) CN Description 5,480 74 >75% Grass cover, Good, HSG C 7,561 98 Roofs, HSG C 19,959 98 Paved parking, HSG C 33,000 94 Weighted Average 5,480 16.61% Pervious Area 27,520 83.39% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.6 10 0.0200 0.11 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.8 130 0.0200 2.87 Shallow Concentrated Flow, Paved Kv= 20.3 fps 1.2 170 0.0140 2.40 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.6 310 Total, Increased to minimum Tc = 6.0 min Appendix D Post-Development Drainage Calculations \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc 12S —� 12P 10S 14P 4- 14S O 0 O RUNOFF TO CB-2 PROP CB-2 ROOF FUNOFF 6'x FTIBC Filters RUNOFF TO FT-2 DMH4 � INFIL /ROP.IDMH-4 U/G INFIL 11 S O 1 CB Q- — 13P 4 — 13S DMH2 O RUNOFF TO CB-1 PROP CB-1 P P DMH-1 PROP DMH-2 4'x4'FTIBC Filterra RUNOFF TO FT-1 ca DMH3 1 R PROP DMH-3 1 S O DESIGN POINT#1 RUNOFF TO ROUTE 125 Subcat Reach PonILinkl Routing Diagram for 4570-Postdrain-Rev1 Prepared by Microsoft, Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC 4570-Postdrain-Revl Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (sq-ft) (subcatchment-numbers) 10,188 74 >75% Grass cover, Good, HSG C (1S, 11S, 12S, 13S, 14S) 19,247 98 Paved parking, HSG C (IS, 11 S, 12S, 13S, 14S) 3,565 98 Roofs, HSG C (10S) 33,000 91 TOTAL AREA 4570-Postdrain-Reel Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 3 Soil Listing (all nodes) Area Soil Subcatchment (sq-ft) Group Numbers 0 HSG A 0 HSG B 33,000 HSG C 1 S, 10S, 11 S, 12S, 13S, 14S 0 HSG D 0 Other 33,000 TOTAL AREA 4570-Postd ra i n-Rev1 Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 4 Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) (sq-ft) Cover 0 0 10,188 0 0 10,188 >75% Grass cover, Good 0 0 19,247 0 0 19,247 Paved parking 0 0 3,565 0 0 3,565 Roofs 0 0 33,000 0 0 33,000 TOTAL AREA 4570-Postdrain-Rev1 Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Pape 5 Pipe Listing (all nodes) Line# Node In-Invert Out-Invert Length Slope n DiamMidth Height Inside-Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 lip 190.10 189.95 22.0 0.0068 0.013 12.0 0.0 0.0 2 12P 190.75 189.95 78.0 0.0103 0.013 12.0 0.0 0.0 3 13P 191.94 191.84 5.0 0.0200 0.013 6.0 0.0 0.0 4 14P 191.14 190.43 70.0 0.0101 0.013 10.0 0.0 0.0 5 DMH1 189.76 189.31 23.0 0.0196 0.013 12.0 0.0 0.0 6 DMH2 190.33 189.86 95.0 0.0049 0.013 12.0 0.0 0.0 7 DMH3 189.21 188.99 45.0 0.0049 0.013 12.0 0.0 0.0 8 DMH4 189.95 189.86 10.0 0.0090 0.013 12.0 0.0 0.0 9 INFIL 190.10 189.95 12.0 0.0125 0.013 12.0 0.0 0.0 4570-Postdrain-Rev1 Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 6 Notes Listing (all nodes) Line# Node Notes Number 1 INFIL RAWL'S RATE OF 1.02in/hr USED FOR FINE SANDY LOAM 4570-Postdrain-Rev1 Type 111 24-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 7 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 4 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1S: RUNOFF TO ROUTE 125 Runoff Area=9,500 sf 61.45% Impervious Runoff Depth=2.02" Flow Length=112' Tc=6.0 min CN=89 Runoff=0.51 cfs 1,597 cf Subcatchment 10S: ROOF RUNOFF Runoff Area=3,565 sf 100.00% Impervious Runoff Depth=2.90" Tc=0.0 min CN=98 Runoff=0.30 cfs 861 cf Subcatchment 11S: RUNOFF TO CB-1 Runoff Area=2,234 sf 66.11% Impervious Runoff Depth=2.10" Flow Length=35' Tc=6.0 min CN=90 Runoff=0.13 cfs 392 cf Subcatchment 12S: RUNOFF TO CB-2 Runoff Area=5,307 sf 76.69% Impervious Runoff Depth=2.28" Flow Length=87' Slope=0.0200 '/' Tc=6.0 min CN=92 Runoff=0.32 cfs 1,010 cf Subcatchment 13S: RUNOFF TO FT-1 Runoff Area=3,402 sf 55.17% Impervious Runoff Depth=1.85" Flow Length=60' Tc=6.0 min CN=87 Runoff=0.17 cfs 525 cf Subcatchment 14S: RUNOFF TO FT-2 Runoff Area=8,992 sf 66.56% Impervious Runoff Depth=2.10" Flow Length=75' Tc=6.0 min CN=90 Runoff=0.50 cfs 1,576 cf Reach 1 R: DESIGN POINT#1 Inflow=1.63 cfs 5,122 cf Outflow=1.63 cfs 5,122 cf Pond 11 P: PROP CB-1 Peak EIev=190.45' Inflow=0.13 cfs 392 cf 12.0" Round Culvert n=0.013 L=22.0' S=0.0068 '/' Outflow=0.13 cfs 392 cf Pond 12P: PROP CB-2 Peak EIev=191.05' Inflow=0.32 cfs 1,010 cf 12.0" Round Culvert n=0.013 L=78.0' S=0.0103 '/' Outflow=0.32 cfs 1,010 cf Pond 13P: 4'x4' FTIBC Filterra Peak EIev=194.81' Storage=10 cf Inflow=0.17 cfs 525 cf Outflow=0.17 cfs 526 cf Pond 14P: 6'x8' FTIBC Filterra Peak EIev=194.05' Storage=32 cf Inflow=0.50 cfs 1,576 cf Outflow=0.50 cfs 1,577 cf Pond DMH1: PROP DMH-1 Peak EIev=190.32' Inflow=1.12 cfs 3,525 cf 12.0" Round Culvert n=0.013 L=23.0' S=0.0196 '/' Outflow=1.12 cfs 3,525 cf Pond DMH2: PROP DMH-2 Peak EIev=190.83' Inflow=0.67 cfs 2,103 cf 12.0" Round Culvert n=0.013 L=95.0' S=0.0049 T Outflow=0.67 cfs 2,103 cf Pond DMH3: PROP DMH-3 Peak EIev=189.87' Inflow=1.12 cfs 3,525 cf 12.0" Round Culvert n=0.013 L=45.0' S=0.0049 '/' Outflow=1.12 cfs 3,525 cf Pond DMH4: PROP. DMH-4 Peak EIev=190.42' Inflow=0.44 cfs 1,422 cf 12.0" Round Culvert n=0.013 L=10.0' S=0.0090 '/' Outflow=0.44 cfs 1,422 cf Pond INFIL: U/G INFIL Peak EIev=193.46' Storage=366 cf Inflow=0.30 cfs 861 cf Discarded=0.02 cfs 841 cf Primary=0.01 cfs 20 cf Outflow=0.03 cfs 861 cf 4570-Postdrain-Rev1 Type 111 24-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 8 Total Runoff Area=33,000 sf Runoff Volume=5,962 cf Average Runoff Depth =2.17" 30.87% Pervious= 10,188 sf 69.13% Impervious =22,812 sf 4570-Postdrain-Rev1 Type ///24-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 1S: RUNOFF TO ROUTE 125 Runoff = 0.51 cfs @ 12.09 hrs, Volume= 1,597 cf, Depth= 2.02" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-year Rainfall=3.13" Area (sf) CN Description 3,662 74 >75% Grass cover, Good, HSG C 5,838 98 Paved parking HSG C 9,500 89 Weighted Average 3,662 38.55% Pervious Area 5,838 61.45% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.0 22 0.0200 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.6 90 0.0140 2.40 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.6 112 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 10S: ROOF RUNOFF [46] Hint: Tc=O (Instant runoff peak depends on dt) Runoff = 0.30 cfs @ 12.00 hrs, Volume= 861 cf, Depth= 2.90" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-year Rainfall=3.13" Area (sf) CN Description 3,565 98 Roofs, HSG C 3,565 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.0 Direct Entry, Summary for Subcatchment 11S: RUNOFF TO CB-1 Runoff = 0.13 cfs @ 12.09 hrs, Volume= 392 cf, Depth= 2.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-year Rainfall=3.13" 4570-Postdrain-Rev1 Type ///24-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 10 Area (sf) CN Description 757 74 >75% Grass cover, Good, HSG C 1,477 98 Paved parking, HSG C 2,234 90 Weighted Average 757 33.89% Pervious Area 1,477 66.11% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.2 15 0.0200 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.1 20 0.0400 4.06 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.3 35 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 12S: RUNOFF TO CB-2 Runoff = 0.32 cfs @ 12.09 hrs, Volume= 1,010 cf, Depth= 2.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-year Rainfall=3.13" Area (sf) CN Description 1,237 74 >75% Grass cover, Good, HSG C 4,070 98 Paved parking, HSG C 5,307 92 Weighted Average 1,237 23.31% Pervious Area 4,070 76.69% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.2 7 0.0200 0.10 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.5 80 0.0200 2.87 Shallow Concentrated Flow, Paved Kv= 20.3 fps 1.7 87 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 13S: RUNOFF TO FT-1 Runoff = 0.17 cfs @ 12.09 hrs, Volume= 525 cf, Depth= 1.85" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-year Rainfall=3.13" Area (sf) CN Description 1,525 74 >75% Grass cover, Good, HSG C 1,877 98 Paved parking, HSG C 3,402 87 Weighted Average 1,525 44.83% Pervious Area 1,877 55.17% Impervious Area 4570-Postdrain-Rev1 Type 1/124-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 11 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.3 25 0.0200 0.13 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.3 20 0.0200 0.99 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.1 15 0.0400 4.06 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.7 60 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 14S: RUNOFF TO FT-2 Runoff = 0.50 cfs @ 12.09 hrs, Volume= 1,576 cf, Depth= 2.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 2-year Rainfall=3.13" Area (sf) CN Description 3,007 74 >75% Grass cover, Good, HSG C 5,985 98 Paved parking HSG C 8,992 90 Weighted Average 3,007 33.44% Pervious Area 5,985 66.56% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.7 20 0.0200 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.2 55 0.0400 4.06 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.9 75 Total, Increased to minimum Tc = 6.0 min Summary for Reach 1R: DESIGN POINT#1 (40] Hint: Not Described (Outflow=Inflow) Inflow Area = 33,000 sf, 69.13% Impervious, Inflow Depth = 1.86" for 2-year event Inflow = 1.63 cfs @ 12.09 hrs, Volume= 5,122 cf Outflow = 1.63 cfs @ 12.09 hrs, Volume= 5,122 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Summary for Pond 11 P: PROP CB-1 Inflow Area = 2,234 sf, 66.11% Impervious, Inflow Depth = 2.10" for 2-year event Inflow = 0.13 cfs @ 12.09 hrs, Volume= 392 cf Outflow = 0.13 cfs @ 12.09 hrs, Volume= 392 cf, Atten= 0%, Lag= 0.0 min Primary = 0.13 cfs @ 12.09 hrs, Volume= 392 cf 4570-Postdrain-Rev1 Type 111 24-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 U 2017 HydroCAD Software Solutions LLC Page 12 Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 190.45' @ 12.09 hrs Flood Elev= 194.10' Device Routing Invert Outlet Devices #1 Primary 190.10' 12.0" Round Culvert L= 22.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 190.10'/ 189.95' S= 0.0068 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.13 cfs @ 12.09 hrs HW=190.45' TW=190.42' (Dynamic Tailwater) L1=Culvert (Outlet Controls 0.13 cfs @ 0.77 fps) Summary for Pond 12P: PROP CB-2 Inflow Area = 5,307 sf, 76.69% Impervious, Inflow Depth = 2.28" for 2-year event Inflow = 0.32 cfs @ 12.09 hrs, Volume= 1,010 cf Outflow = 0.32 cfs @ 12.09 hrs, Volume= 1,010 cf, Atten= 0%, Lag= 0.0 min Primary = 0.32 cfs @ 12.09 hrs, Volume= 1,010 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 191.05' @ 12.09 hrs Flood Elev= 194.75' Device Routing Invert Outlet Devices #1 Primary 190.75' 12.0" Round Culvert L= 78.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 190.75' / 189.95' S= 0.0103 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.32 cfs @ 12.09 hrs HW=191.05' TW=190.42' (Dynamic Tailwater) L1=Culvert (Outlet Controls 0.32 cfs @ 2.39 fps) Summary for Pond 13P: 4'x4' FTIBC Filterra [87] Warning: Oscillations may require smaller dt or Finer Routing (severity=574) Inflow Area = 3,402 sf, 55.17% Impervious, Inflow Depth = 1.85" for 2-year event Inflow = 0.17 cfs @ 12.09 hrs, Volume= 525 cf Outflow = 0.17 cfs @ 12.09 hrs, Volume= 526 cf, Atten= 0%, Lag= 0.1 min Primary = 0.17 cfs @ 12.09 hrs, Volume= 526 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 194.81' @ 12.09 hrs Surf.Area= 16 sf Storage= 10 cf Flood Elev= 195.40' Surf.Area= 16 sf Storage= 16 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.7 min ( 820.5 - 819.8 ) 4570-Postdrain-Rev1 Type ///24-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10 00-20 s/n 01710 02017 HydroCAD Software Solutions LLC Page 13 Volume Invert Avail.Storage Storage Description #1 194.19' 16 cf 4.00'W x 4.00'L x 1.00'H Prismatoid Device Routing Invert Outlet Devices #1 Primary 191.94' 6.0" Round Culvert L= 5.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 191.94' / 191.84' S= 0.0200 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.20 sf #2 Device 1 194.19' 140.000 in/hr Exfiltration over Surface area #3 Device 1 194.73' 6.0" Horiz. Overflow Bypass C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.17 cfs @ 12.09 hrs HW=194.81' TW=190.83' (Dynamic Tailwater) L1=Culvert (Passes 0.17 cfs of 1.53 cfs potential flow) �__3=Overflow 2=Exfiltration (Exfiltration Controls 0.05 cfs) Bypass (Weir Controls 0.12 cfs @ 0.93 fps) Summary for Pond 14P: 6'x8' FTIBC Filterra [87] Warning: Oscillations may require smaller dt or Finer Routing (severity=574) Inflow Area = 8,992 sf, 66.56% Impervious, Inflow Depth = 2.10" for 2-year event Inflow = 0.50 cfs @ 12.09 hrs, Volume= 1,576 cf Outflow = 0.50 cfs @ 12.09 hrs, Volume= 1,577 cf, Atten= 0%, Lag= 0.2 min Primary = 0.50 cfs @ 12.09 hrs, Volume= 1,577 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 194.05' @ 12.09 hrs Surf.Area=48 sf Storage= 32 cf Flood Elev= 194.60' Surf.Area=48 sf Storage=48 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.7 min ( 808.5 - 807.8 ) Volume Invert Avail.Storage Storage Description #1 193.39' 48 cf 8.00'W x 6.00'L x 1.00'H Prismatoid Device Routing Invert Outlet Devices #1 Primary 191.14' 10.0" Round Culvert L= 70.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 191.14' / 190.43' S= 0.0101 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.55 sf #2 Device 1 193.39' 140.000 in/hr Exfiltration over Surface area #3 Device 1 193.93' 10.0" Horiz. Overflow Bypass C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.50 cfs @ 12.09 hrs HW=194.05' TW=190.83' (Dynamic Tailwater) t- =Culvert (Passes 0.50 cfs of 3.52 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.16 cfs) 3 Overflow Bypass (Weir Controls 0.35 cfs @ 1.12 fps) 4570-Postdrain-Rev1 Type 111 24-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10.00-20 s/n 01710 C 2017 HydroCAD Software Solutions LLC Page 14 Summary for Pond DMH1: PROP DMH-1 Inflow Area = 23,500 sf, 72.23% Impervious, Inflow Depth = 1.80" for 2-year event Inflow = 1.12 cfs @ 12.09 hrs, Volume= 3,525 cf Outflow = 1.12 cfs @ 12.09 hrs, Volume= 3,525 cf, Atten= 0%, Lag= 0.0 min Primary = 1.12 cfs @ 12.09 hrs, Volume= 3,525 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 190.32' @ 12.09 hrs Flood Elev= 195.20' Device Routing Invert Outlet Devices #1 Primary 189.76' 12.0" Round Culvert L= 23.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 189.76'/ 189.31' S= 0.0196 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.12 cfs @ 12.09 hrs HW=190.32' TW=189.87' (Dynamic Tailwater) t-1=Culvert (Outlet Controls 1.12 cfs @ 3.54 fps) Summary for Pond DMH2: PROP DMH-2 Inflow Area = 12,394 sf, 63.43% Impervious, Inflow Depth = 2.04" for 2-year event Inflow = 0.67 cfs @ 12.09 hrs, Volume= 2,103 cf Outflow = 0.67 cfs @ 12.09 hrs, Volume= 2,103 cf, Atten= 0%, Lag= 0.0 min Primary = 0.67 cfs @ 12.09 hrs, Volume= 2,103 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 190.83' @ 12.09 hrs Flood Elev= 195.90' Device Routing Invert Outlet Devices #1 Primary 190.33' 12.0" Round Culvert L= 95.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 190.33' / 189.86' S= 0.0049 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.67 cfs @ 12.09 hrs HW=190.83' TW=190.32' (Dynamic Tailwater) t-1=Culvert (Outlet Controls 0.67 cfs @ 2.47 fps) Summary for Pond DMH3: PROP DMH-3 Inflow Area = 23,500 sf, 72.23% Impervious, Inflow Depth = 1.80" for 2-year event Inflow = 1.12 cfs @ 12.09 hrs, Volume= 3,525 cf Outflow = 1.12 cfs @ 12.09 hrs, Volume= 3,525 cf, Atten= 0%, Lag= 0.0 min Primary = 1.12 cfs @ 12.09 hrs, Volume= 3,525 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 189.87' @ 12.09 hrs Flood Elev= 194.10' 4570-Postdrain-Rev1 Type/1/24-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 15 Device Routing Invert Outlet Devices #1 Primary 189.21' 12.0" Round Culvert L=45.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 189.21' / 188.99' S= 0.0049 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.12 cfs @ 12.09 hrs HW=189.87' TW=0.00' (Dynamic Tailwater) L1=Culvert (Barrel Controls 1.12 cfs @ 2.90 fps) Summary for Pond DMH4: PROP. DMH-4 Inflow Area = 11,106 sf, 82.05% Impervious, Inflow Depth = 1.54" for 2-year event Inflow = 0.44 cfs @ 12.09 hrs, Volume= 1,422 cf Outflow = 0.44 cfs @ 12.09 hrs, Volume= 1,422 cf, Atten= 0%, Lag= 0.0 min Primary = 0.44 cfs @ 12.09 hrs, Volume= 1,422 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 190.42' @ 12.09 hrs Flood Elev= 194.85' Device Routing Invert Outlet Devices #1 Primary 189.95' 12.0" Round Culvert L= 10.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 189.95'/ 189.86' S= 0.0090 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.44 cfs @ 12.09 hrs HW=190.42' TW=190.32' (Dynamic Tailwater) L1=Culvert (Outlet Controls 0.44 cfs @ 1.80 fps) Summary for Pond INFIL: U/G INFIL RAWL'S RATE OF 1.02in/hr USED FOR FINE SANDY LOAM Inflow Area = 3,565 sf,100.00% Impervious, Inflow Depth = 2.90" for 2-year event Inflow = 0.30 cfs @ 12.00 hrs, Volume= 861 cf Outflow = 0.03 cfs @ 12.64 hrs, Volume= 861 cf, Atten= 91%, Lag= 38.3 min Discarded = 0.02 cfs @ 12.64 hrs, Volume= 841 cf Primary = 0.01 cfs @ 12.64 hrs, Volume= 20 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 193.46' @ 12.64 hrs Surf.Area=433 sf Storage= 366 cf Flood Elev= 194.33' Surf.Area=433 sf Storage= 528 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 209.9 min ( 961.2 - 751.3 ) t 4570-Postdrain-Rev1 Type ///24-hr 2-year Rainfall=3.13" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10 00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 16 Volume Invert Avail.Storage Storage Description #1A 192.00' 322 cf 8.17'W x 53.04%x 2.33'H Field A 1,011 cf Overall -206 cf Embedded = 804 cf x 40.0% Voids #2A 192.50' 206 cf ADS StormTech RC-310 +Cap x 14 Inside#1 Effective Size= 28.9"W x 16.0"H => 2.07 sf x 7.12'L = 14.7 cf Overall Size= 34.0"W x 16.0"H x 7.561 with 0.44' Overlap 2 Rows of 7 Chambers 528 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 192.00' 1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 189.00' #2 Primary 190.10' 12.0" Round Culvert L= 12.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 190.10'/ 189.95' S= 0.0125 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #3 Device 2 193.45' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.02 cfs @ 12.64 hrs HW=193.46' (Free Discharge) L1=Exfiltration ( Controls 0.02 cfs) Primary OutFlow Max=0.01 cfs @ 12.64 hrs HW=193.46' TW=190.09' (Dynamic Tailwater) Z2=Culvert (Passes 0.01 cfs of 6.40 cfs potential flow) t3=Orifice/Grate (Weir Controls 0.01 cfs @ 0.34 fps) 4570-Postdrain-Reel Type Ill 24-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroC:Ann 10 nn-20 can 01710 ©2017 HydroCAD Software Solutions LLC Page 17 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 4 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1S: RUNOFF TO ROUTE 125 Runoff Area=9,500 sf 61.45% Impervious Runoff Depth=3.57" Flow Length=112' Tc=6.0 min CN=89 Runoff=0.89 cfs 2,827 cf Subcatchment 10S: ROOF RUNOFF Runoff Area=3,565 sf 100.00% Impervious Runoff Depth=4.55" Tc=0.0 min CN=98 Runoff=0.47 cfs 1,353 cf Subcatchment 11S: RUNOFF TO CB-1 Runoff Area=2,234 sf 66.11% Impervious Runoff Depth=3.67" Flow Length=35' Tc=6.0 min CN=90 Runoff=0.21 cfs 684 cf Subcatchment 12S: RUNOFF TO CB-2 Runoff Area=5,307 sf 76.69% Impervious Runoff Depth=3.88" Flow Length=87' Slope=0.0200 '/' Tc=6.0 min CN=92 Runoff=0.53 cfs 1,718 cf Subcatchment 13S: RUNOFF TO FT-1 Runoff Area=3,402 sf 55.17% Impervious Runoff Depth=3.37" Flow Length=60' Tc=6.0 min CN=87 Runoff=0.30 cfs 955 cf Subcatchment 14S: RUNOFF TO FT-2 Runoff Area=8,992 sf 66.56% Impervious Runoff Depth=3.67" Flow Length=75' Tc=6.0 min CN=90 Runoff=0.86 cfs 2,753 cf Reach 1R: DESIGN POINT#1 Inflow=3.05 cfs 9,289 cf Outflow=3.05 cfs 9,289 cf Pond 11P: PROP CB-1 Peak EIev=190.79' Inflow=0.21 cfs 684 cf 12.0" Round Culvert n=0.013 L=22.0' S=0.0068 '/' Outflow=0.21 cfs 684 cf Pond 12P: PROP CB-2 Peak EIev=191.20' Inflow=0.53 cfs 1,718 cf 12.0" Round Culvert n=0.013 L=78.0' S=0.0103 '/' Outflow=0.53 cfs 1,718 cf Pond 13P: 4'x4' FTIBC Filterra Peak EIev=194.86' Storage=11 cf Inflow=0.30 cfs 955 cf Outflow=0.30 cfs 956 cf Pond 14P: 6'x8' FTIBC Filterra Peak EIev=194.12' Storage=35 cf Inflow=0.86 cfs 2,753 cf Outflow=0.86 cfs 2,753 cf Pond DMH1: PROP DMH-1 Peak EIev=190.67' Inflow=2.17 cfs 6,462 cf 12.0" Round Culvert n=0.013 L=23.0' S=0.0196 '/' Outflow=2.17 cfs 6,462 cf Pond DMH2: PROP DMH-2 Peak EIev=191.09' Inflow=1.16 cfs 3,709 cf 12.0" Round Culvert n=0.013 L=95.0' S=0.0049 T Outflow=1.16 cfs 3,709 cf Pond DMH3: PROP DMH-3 Peak EIev=190.21' Inflow=2.17 cfs 6,462 cf 12.0" Round Culvert n=0.013 L=45.0' S=0.0049 '/' Outflow=2.17 cfs 6,462 cf Pond DMH4: PROP. DMH-4 Peak EIev=190.78' Inflow=1.03 cfs 2,753 cf 12.0" Round Culvert n=0.013 L=10.0' S=0.0090 '/' Outflow=1.03 cfs 2,753 cf Pond INFIL: U/G INFIL Peak EIev=193.56' Storage=389 cf Inflow=0.47 cfs 1,353 cf Discarded=0.02 cfs 1,001 cf Primary=0.37 cfs 351 cf Outflow=0.39 cfs 1,353 cf 4570-Postdrain-Rev1 Type III 24-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 18 Total Runoff Area=33,000 sf Runoff Volume= 10,290 cf Average Runoff Depth =3.74" 30.87% Pervious = 10,188 sf 69.13% Impervious=22,812 sf 4570-Postdrain-Rev1 Type/1/24-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment 1S: RUNOFF TO ROUTE 125 Runoff = 0.89 cfs @ 12.09 hrs, Volume= 2,827 cf, Depth= 3.57" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-year Rainfall=4.79" Area (sfl CN Description 3,662 74 >75% Grass cover, Good, HSG C 5,838 98 Paved parking HSG C 9,500 89 Weighted Average 3,662 38.55% Pervious Area 5,838 61.45% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.0 22 0.0200 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.6 90 0.0140 2.40 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.6 112 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 105: ROOF RUNOFF [46] Hint: Tc=O (Instant runoff peak depends on dt) Runoff = 0.47 cfs @ 12.00 hrs, Volume= 1,353 cf, Depth= 4.55" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-year Rainfall=4.79" Area (sfl CN Description 3,565 98 Roofs, HSG C 3,565 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.0 Direct Entry, Summary for Subcatchment 11S: RUNOFF TO CB-1 Runoff = 0.21 cfs @ 12.09 hrs, Volume= 684 cf, Depth= 3.67" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-year Rainfall=4.79" 4570-Postdrain-Rev1 Type 111 24-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 20 Area (sf) CN Description 757 74 >75% Grass cover, Good, HSG C 1,477 98 Paved parking, HSG C 2,234 90 Weighted Average 757 33.89% Pervious Area 1,477 66.11% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.2 15 0.0200 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.1 20 0.0400 4.06 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.3 35 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 12S: RUNOFF TO CB-2 Runoff = 0.53 cfs @ 12.08 hrs, Volume= 1,718 cf, Depth= 3.88" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-year Rainfall=4.79" Area (sf) CN Description 1,237 74 >75% Grass cover, Good, HSG C 4,070 98 Paved parking, HSG C 5,307 92 Weighted Average 1,237 23.31% Pervious Area 4,070 76.69% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.2 7 0.0200 0.10 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.5 80 0.0200 2.87 Shallow Concentrated Flow, Paved Kv= 20.3 fps 1.7 87 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 13S: RUNOFF TO FT-1 Runoff = 0.30 cfs @ 12.09 hrs, Volume= 955 cf, Depth= 3.37" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-year Rainfall=4.79" Area (sf) CN Description 1,525 74 >75% Grass cover, Good, HSG C 1,877 98 Paved parking, HSG C 3,402 87 Weighted Average 1,525 44.83% Pervious Area 1,877 55.17% Impervious Area 4570-Postdrain-Rev1 Type Ill 24-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 21 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.3 25 0.0200 0.13 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.3 20 0.0200 0.99 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.1 15 0.0400 4.06 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.7 60 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 14S: RUNOFF TO FT-2 Runoff = 0.86 cfs @ 12.09 hrs, Volume= 2,753 cf, Depth= 3.67" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 10-year Rainfall=4.79" Area (sf) CN Description 3,007 74 >75% Grass cover, Good, HSG C 5,985 98 Paved parking, HSG C 8,992 90 Weighted Average 3,007 33.44% Pervious Area 5,985 66.56% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.7 20 0.0200 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.2 55 0.0400 4.06 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.9 75 Total, Increased to minimum Tc = 6.0 min Summary for Reach 1 R: DESIGN POINT#1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 33,000 sf, 69.13% Impervious, Inflow Depth = 3.38" for 10-year event Inflow = 3.05 cfs @ 12.08 hrs, Volume= 9,289 cf Outflow = 3.05 cfs @ 12.08 hrs, Volume= 9,289 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Summary for Pond 11 P: PROP CB-1 Inflow Area = 2,234 sf, 66.11% Impervious, Inflow Depth = 3.67" for 10-year event Inflow = 0.21 cfs @ 12.09 hrs, Volume= 684 cf Outflow = 0.21 cfs @ 12.09 hrs, Volume= 684 cf, Atten= 0%, Lag= 0.0 min Primary = 0.21 cfs @ 12.09 hrs, Volume= 684 cf 4570-Postdrain-Rev1 Type/1/24-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 22 Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 190.79' @ 12.07 hrs Flood Elev= 194.10' Device Routing Invert Outlet Devices #1 Primary 190.10' 12.0" Round Culvert L= 22.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 190.10' / 189.95' S= 0.0068 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.21 cfs @ 12.09 hrs HW=190.78' TW=190.77' (Dynamic Tailwater) t-1=Culvert (Outlet Controls 0.21 cfs @ 0.53 fps) Summary for Pond 12P: PROP CB-2 Inflow Area = 5,307 sf, 76.69% Impervious, Inflow Depth = 3.88" for 10-year event Inflow = 0.53 cfs @ 12.08 hrs, Volume= 1,718 cf Outflow = 0.53 cfs @ 12.08 hrs, Volume= 1,718 cf, Atten= 0%, Lag= 0.0 min Primary = 0.53 cfs @ 12.08 hrs, Volume= 1,718 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 191.20' @ 12.08 hrs Flood Elev= 194.75' Device Routing Invert Outlet Devices #1 Primary 190.75' 12.0" Round Culvert L= 78.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 190.75' / 189.95' S= 0.0103 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.53 cfs @ 12.08 hrs HW=191.19' TW=190.77' (Dynamic Tailwater) L1=Culvert (Outlet Controls 0.53 cfs @ 2.30 fps) Summary for Pond 13P: 4'x4' FTIBC Filterra [87] Warning: Oscillations may require smaller dt or Finer Routing (severity=566) Inflow Area = 3,402 sf, 55.17% Impervious, Inflow Depth = 3.37" for 10-year event Inflow = 0.30 cfs @ 12.09 hrs, Volume= 955 cf Outflow = 0.30 cfs @ 12.09 hrs, Volume= 956 cf, Atten= 0%, Lag= 0.1 min Primary = 0.30 cfs @ 12.09 hrs, Volume= 956 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 194.86' @ 12.09 hrs Surf.Area= 16 sf Storage= 11 cf Flood Elev= 195.40' Surf.Area= 16 sf Storage= 16 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.6 min ( 803.4- 802.8 ) 4570-Postdrain-Rev1 Type ///24-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10.00-20 s/n 01710 0 2017 HydroCAD Software Solutions LLC Page 23 Volume Invert Avail.Storage Storage Description #1 194.19' 16 cf 4.00'W x 4.001 x 1.00'H Prismatoid Device Routing Invert Outlet Devices #1 Primary 191.94' 6.0" Round Culvert L= 5.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 191.94' / 191.84' S= 0.0200 7 Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.20 sf #2 Device 1 194.19' 140.000 in/hr Exfiltration over Surface area #3 Device 1 194.73' 6.0" Horiz. Overflow Bypass C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.30 cfs @ 12.09 hrs HW=194.86' TW=191.09' (Dynamic Tailwater) t1=Culvert (Passes 0.30 cfs of 1.55 cfs potential flow) �2=Exfiltration (Exfiltration Controls 0.05 cfs) 3=Overflow Bypass (Weir Controls 0.25 cfs @ 1.20 fps) Summary for Pond 14P: 6'x8' FTIBC Filterra [87] Warning: Oscillations may require smaller dt or Finer Routing (severity=567) Inflow Area = 8,992 sf, 66.56% Impervious, Inflow Depth = 3.67" for 10-year event Inflow = 0.86 cfs @ 12.09 hrs, Volume= 2,753 cf Outflow = 0.86 cfs @ 12.09 hrs, Volume= 2,753 cf, Atten= 0%, Lag= 0.1 min Primary = 0.86 cfs @ 12.09 hrs, Volume= 2,753 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 194.12' @ 12.09 hrs Surf.Area=48 sf Storage= 35 cf Flood Elev= 194.60' Surf.Area=48 sf Storage=48 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.6 min (792.8 - 792.2 ) Volume Invert Avail.Storage Storage Description #1 193.39' 48 cf 8.00'W x 6.00'L x 1.00'H Prismatoid Device Routing Invert Outlet Devices #1 Primary 191.14' 10.0" Round Culvert L= 70.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 191.14'/ 190.43' S= 0.0101 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.55 sf #2 Device 1 193.39' 140.000 in/hr Exfiltration over Surface area #3 Device 1 193.93' 10.0" Horiz. Overflow Bypass C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.86 cfs @ 12.09 hrs HW=194.12' TW=191.09' (Dynamic Tailwater) L =Culvert (Passes 0.86 cfs of 3.57 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.16 cfs) 3 Overflow Bypass (Weir Controls 0.70 cfs @ 1.42 fps) 4570-Postdrain-Rev1 Type/1/24-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 O 2017 HydroCAD Software Solutions LLC Page 24 Summary for Pond DMH1: PROP DMH-1 Inflow Area = 23,500 sf, 72.23% Impervious, Inflow Depth = 3.30" for 10-year event Inflow = 2.17 cfs @ 12.08 hrs, Volume= 6,462 cf Outflow = 2.17 cfs @ 12.08 hrs, Volume= 6,462 cf, Atten= 0%, Lag= 0.0 min Primary = 2.17 cfs @ 12.08 hrs, Volume= 6,462 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 190.67' @ 12.08 hrs Flood Elev= 195.20' Device Routing Invert Outlet Devices #1 Primary 189.76' 12.0" Round Culvert L= 23.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 189.76'/ 189.31' S= 0.0196 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=2.16 cfs @ 12.08 hrs HW=190.67' TW=190.21' (Dynamic Tailwater) Z1=Culvert (Outlet Controls 2.16 cfs @ 3.77 fps) Summary for Pond DMH2: PROP DMH-2 Inflow Area = 12,394 sf, 63.43% Impervious, Inflow Depth = 3.59" for 10-year event Inflow = 1.16 cfs @ 12.09 hrs, Volume= 3,709 cf Outflow = 1.16 cfs @ 12.09 hrs, Volume= 3,709 cf, Atten= 0%, Lag= 0.0 min Primary = 1.16 cfs @ 12.09 hrs, Volume= 3,709 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 191.09' @ 12.08 hrs Flood Elev= 195.90' Device Routing Invert Outlet Devices #1 Primary 190.33' 12.0" Round Culvert L= 95.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 190.33' / 189.86' S= 0.0049 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.16 cfs @ 12.09 hrs HW=191.09' TW=190.67' (Dynamic Tailwater) L1=Culvert (Outlet Controls 1.16 cfs @ 2.53 fps) Summary for Pond DMH3: PROP DMH-3 Inflow Area = 23,500 sf, 72.23% Impervious, Inflow Depth = 3.30" for 10-year event Inflow = 2.17 cfs @ 12.08 hrs, Volume= 6,462 cf Outflow = 2.17 cfs @ 12.08 hrs, Volume= 6,462 cf, Atten= 0%, Lag= 0.0 min Primary = 2.17 cfs @ 12.08 hrs, Volume= 6,462 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 190.21' @ 12.08 hrs Flood Elev= 194.10' 4570-Postdrain-Revl Type 11124-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 25 Device Routing Invert Outlet Devices #1 Primary 189.21' 12.0" Round Culvert L= 45.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 189.21'/ 188.99' S= 0.0049 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=2.16 cfs @ 12.08 hrs HW=190.21' TW=0.00' (Dynamic Tailwater) L1=Culvert (Barrel Controls 2.16 cfs @ 3.41 fps) Summary for Pond DMH4: PROP. DMH-4 Inflow Area = 11,106 sf, 82.05% Impervious, Inflow Depth = 2.97" for 10-year event Inflow = 1.03 cfs @ 12.06 hrs, Volume= 2,753 cf Outflow = 1.03 cfs @ 12.06 hrs, Volume= 2,753 cf, Atten= 0%, Lag= 0.0 min Primary = 1.03 cfs @ 12.06 hrs, Volume= 2,753 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 190.78' @ 12.07 hrs Flood Elev= 194.85' Device Routing Invert Outlet Devices #1 Primary 189.95' 12.0" Round Culvert L= 10.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 189.95' / 189.86' S= 0.0090 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.03 cfs @ 12.06 hrs HW=190.77' TW=190.66' (Dynamic Tailwater) L1=Culvert (Outlet Controls 1.03 cfs @ 2.02 fps) Summary for Pond INFIL: U/G INFIL RAWL'S RATE OF 1.02in/hr USED FOR FINE SANDY LOAM Inflow Area = 3,565 sf,100.00% Impervious, Inflow Depth = 4.55" for 10-year event Inflow = 0.47 cfs @ 12.00 hrs, Volume= 1,353 cf Outflow = 0.39 cfs @ 12.03 hrs, Volume= 1,353 cf, Atten= 17%, Lag= 1.9 min Discarded = 0.02 cfs @ 12.03 hrs, Volume= 1,001 cf Primary = 0.37 cfs @ 12.03 hrs, Volume= 351 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 193.56' @ 12.03 hrs Surf.Area=433 sf Storage= 389 cf Flood Elev= 194.33' Surf.Area= 433 sf Storage= 528 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 168.6 min ( 911.7- 743.2 ) 4570-Postdrain-Rev1 Type 111 24-hr 10-year Rainfall=4.79" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 0 2017 HydroCAD Software Solutions LLC Page 26 Volume Invert Avail Storage Storage Description #1A 192.00' 322 cf 8.17'W x 53.04'L x 2.33'H Field A 1,011 cf Overall - 206 cf Embedded = 804 cf x 40.0%Voids #2A 192.50' 206 cf ADS StormTech RC-310+Cap x 14 Inside#1 Effective Size= 28.9"W x 16.0"H => 2.07 sf x 7.121 = 14.7 cf Overall Size= 34.0"W x 16.0"H x 7.561 with 0.44' Overlap 2 Rows of 7 Chambers 528 cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 192.00' 1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 189.00' #2 Primary 190.10' 12.0" Round Culvert L= 12.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 190.10' / 189.95' S= 0.0125 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #3 Device 2 193.45' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Discarded OutFlow Max=0.02 cfs @ 12.03 hrs HW=193.56' (Free Discharge) t-1=Exfiltration ( Controls 0.02 cfs) Primary OutFlow Max=0.37 cfs @ 12.03 hrs HW=193.56' TW=190.70' (Dynamic Tailwater) t-tCulvert (Passes 0.37 cfs of 6.39 cfs potential flow) 3=Orifice/Grate (Weir Controls 0.37 cfs @ 1.08 fps) 4570-Postdrain-Revl Type 11124-hr 100-year Rainfall=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 27 Time span=0.00-30.00 hrs, dt=0.01 hrs, 3001 points x 4 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Dyn-Stor-Ind method - Pond routing by Dyn-Stor-Ind method Subcatchment 1S: RUNOFF TO ROUTE 125 Runoff Area=9,500 sf 61.45% Impervious Runoff Depth=7.49" Flow Length=112' Tc=6.0 min CN=89 Runoff=1.79 cfs 5,932 cf Subcatchment 10S: ROOF RUNOFF Runoff Area=3,565 sf 100.00% Impervious Runoff Depth=8.58" Tc=0.0 min CN=98 Runoff=0.86 cfs 2,549 cf Subcatchment 11S: RUNOFF TO CB-1 Runoff Area=2,234 sf 66.11% Impervious Runoff Depth=7.61" Flow Length=35' Tc=6.0 min CN=90 Runoff=0.43 cfs 1,417 cf Subcatchment 12S: RUNOFF TO CB-2 Runoff Area=5,307 sf 76.69% Impervious Runoff Depth=7.86" Flow Length=87' Slope=0.0200 '/' Tc=6.0 min CN=92 Runoff=1.03 cfs 3,474 cf Subcatchment 13S: RUNOFF TO FT-1 Runoff Area=3,402 sf 55.17% Impervious Runoff Depth=7.25" Flow Length=60' Tc=6.0 min CN=87 Runoff=0.63 cfs 2,055 cf Subcatchment 14S: RUNOFF TO FT-2 Runoff Area=8,992 sf 66.56% Impervious Runoff Depth=7.61" Flow Length=75' Tc=6.0 min CN=90 Runoff=1.71 cfs 5,705 cf Reach 1R: DESIGN POINT#1 Inflow=6.05 cfs 19,868 cf Outflow=6.05 cfs 19,868 cf Pond 11P: PROP CB-1 Peak Elev=192.86' Inflow=0.43 cfs 1,417 cf 12.0" Round Culvert n=0.013 L=22.0' S=0.0068 '/' Outflow=0.43 cfs 1,417 cf Pond 12P: PROP CB-2 Peak Elev=192.96' Inflow=1.03 cfs 3,474 cf 12.0" Round Culvert n=0.013 L=78.0' S=0.0103 '/' Outflow=1.03 cfs 3,474 cf Pond 13P: 4'x4' FTIBC Filterra Peak EIev=195.10' Storage=15 cf Inflow=0.63 cfs 2,055 cf Outflow=0.63 cfs 2,055 cf Pond 14P: 6'x8' FTIBC Filterra Peak EIev=194.28' Storage=43 cf Inflow=1.71 cfs 5,705 cf Outflow=1.71 cfs 5,705 cf Pond DMH1: PROP DMH-1 Peak EIev=192.59' Inflow=4.26 cfs 13,937 cf 12.0" Round Culvert n=0.013 L=23.0' S=0.0196 '/' Outflow=4.26 cfs 13,937 cf Pond DMH2: PROP DMH-2 Peak EIev=193.19' Inflow=2.33 cfs 7,761 cf 12.0" Round Culvert n=0.013 L=95.0' S=0.0049 '/' Outflow=2.33 cfs 7,761 cf Pond DMH3: PROP DMH-3 Peak EIev=191.32' Inflow=4.26 cfs 13,937 cf 12.0" Round Culvert n=0.013 L=45.0' S=0.0049 '/' Outflow=4.26 cfs 13,937 cf Pond DMH4: PROP. DMH-4 Peak EIev=192.85' Inflow=1.98 cfs 6,176 cf 12.0" Round Culvert n=0.013 L=10.0' S=0.0090 '/' Outflow=1.98 cfs 6,176 cf Pond INFIL: U/G INFIL Peak EIev=193.64' Storage=405 cf Inflow=0.86 cfs 2,549 cf Discarded=0.02 cfs 1,265 cf Primary=0.83 cfs 1,284 cf Outflow=0.84 cfs 2,549 cf 4570-Postdrain-Reel Type 11124-hr 100-year Rainfall=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 28 Total Runoff Area= 33,000 sf Runoff Volume=21,133 cf Average Runoff Depth =7.68" 30.87% Pervious= 10,188 sf 69.13% Impervious=22,812 sf 4570-Postdrain-Rev1 Type 111 24-hr 100-year Rainfall=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 29 Summary for Subcatchment 1S: RUNOFF TO ROUTE 125 Runoff = 1.79 cfs @ 12.08 hrs, Volume= 5,932 cf, Depth= 7.49" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-year Rainfall=8.82" Area (sf) CN Description 3,662 74 >75% Grass cover, Good, HSG C 5,838 98 Paved parking HSG C 9,500 89 Weighted Average 3,662 38.55% Pervious Area 5,838 61.45% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.0 22 0.0200 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.6 90 0.0140 2.40 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.6 112 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 10S: ROOF RUNOFF [46] Hint: Tc=O (Instant runoff peak depends on dt) Runoff = 0.86 cfs @ 12.00 hrs, Volume= 2,549 cf, Depth= 8.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-year Rainfall=8.82" Area (sf) CN Description 3,565 98 Roofs, HSG C 3,565 100.00% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 0.0 Direct Entry, Summary for Subcatchment 115: RUNOFF TO CB-1 Runoff = 0.43 cfs @ 12.08 hrs, Volume= 1,417 cf, Depth= 7.61" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-year Rainfall=8.82" 4570-Postdrain-Rev1 Type ///24-hr 100-year Rainfall=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10.00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 30 Area (sf) CN Description 757 74 >75% Grass cover, Good, HSG C 1,477 98 Paved parking HSG C 2,234 90 Weighted Average 757 33.89% Pervious Area 1,477 66.11% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.2 15 0.0200 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.1 20 0.0400 4.06 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.3 35 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 12S: RUNOFF TO CB-2 Runoff = 1.03 cfs @ 12.08 hrs, Volume= 3,474 cf, Depth= 7.86" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-year Rainfall=8.82" Area (sf) CN Description 1,237 74 >75% Grass cover, Good, HSG C 4,070 98 Paved parking HSG C 5,307 92 Weighted Average 1,237 23.31% Pervious Area 4,070 76.69% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 1.2 7 0.0200 0.10 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.5 80 0.0200 2.87 Shallow Concentrated Flow, Paved Kv= 20.3 fps 1.7 87 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 13S: RUNOFF TO FT-1 Runoff = 0.63 cfs @ 12.08 hrs, Volume= 2,055 cf, Depth= 7.25" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-year Rainfall=8.82" Area (sf) CN Description 1,525 74 >75% Grass cover, Good, HSG C 1,877 98 Paved parking, HSG C 3,402 87 Weighted Average 1,525 44.83% Pervious Area 1,877 55.17% Impervious Area 4570-Postdrain-Rev1 Type/1/24-hr 100-year Rainfall=8.82" Prepared by Microsoft 'Printed 4/24/2019 HvdroCAD® 10.00-20 s/n 01710 0 2017 HvdroCAD Software Solutions LLC Page 31 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 3.3 25 0.0200 0.13 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.3 20 0.0200 0.99 Shallow Concentrated Flow, Short Grass Pasture Kv= 7.0 fps 0.1 15 0.0400 4.06 Shallow Concentrated Flow, Paved Kv= 20.3 fps 3.7 60 Total, Increased to minimum Tc = 6.0 min Summary for Subcatchment 14S: RUNOFF TO FT-2 Runoff = 1.71 cfs @ 12.08 hrs, Volume= 5,705 cf, Depth= 7.61" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs Type III 24-hr 100-year Rainfall=8.82" Area (sf) CN Description 3,007 74 >75% Grass cover, Good, HSG C 5,985 98 Paved parking HSG C 8,992 90 Weighted Average 3,007 33.44% Pervious Area 5,985 66.56% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 2.7 20 0.0200 0.12 Sheet Flow, Grass: Short n= 0.150 P2= 3.13" 0.2 55 0.0400 4.06 Shallow Concentrated Flow, Paved Kv= 20.3 fps 2.9 75 Total, Increased to minimum Tc = 6.0 min Summary for Reach 1 R: DESIGN POINT#1 [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 33,000 sf, 69.13% Impervious, Inflow Depth = 7.22" for 100-year event Inflow = 6.05 cfs @ 12.08 hrs, Volume= 19,868 cf Outflow = 6.05 cfs @ 12.08 hrs, Volume= 19,868 cf, Atten= 0%, Lag= 0.0 min Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Summary for Pond 11 P: PROP CB-1 Inflow Area = 2,234 sf, 66.11% Impervious, Inflow Depth = 7.61" for 100-year event Inflow = 0.43 cfs @ 12.08 hrs, Volume= 1,417 cf Outflow = 0.43 cfs @ 12.08 hrs, Volume= 1,417 cf, Atten= 0%, Lag= 0.0 min Primary = 0.43 cfs @ 12.08 hrs, Volume= 1,417 cf 4570-Postdrain-Rev1 Type/1/24-hr 100-year Rainfall=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10 00-20 s/n 01710 O 2017 HydroCAD Software Solutions LLC Page 32 Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 192.86' @ 12.08 hrs Flood Elev= 194.10' Device Routing Invert Outlet Devices #1 Primary 190.10' 12.0" Round Culvert L= 22.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 190.10' / 189.95' S= 0.0068 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=0.42 cfs @ 12.08 hrs HW=192.84' TW=192.82' (Dynamic Tailwater) L1=Culvert (Inlet Controls 0.42 cfs @ 0.54 fps) Summary for Pond 12P: PROP CB-2 Inflow Area = 5,307 sf, 76.69% Impervious, Inflow Depth = 7.86" for 100-year event Inflow = 1.03 cfs @ 12.08 hrs, Volume= 3,474 cf Outflow = 1.03 cfs @ 12.08 hrs, Volume= 3,474 cf, Atten= 0%, Lag= 0.0 min Primary = 1.03 cfs @ 12.08 hrs, Volume= 3,474 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 192.96' @ 12.08 hrs Flood Elev= 194.75' Device Routing Invert Outlet Devices #1 Primary 190.75' 12.0" Round Culvert L= 78.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 190.75'/ 189.95' S= 0.0103 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.02 cfs @ 12.08 hrs HW=192.93' TW=192.83' (Dynamic Tailwater) Z1=Culvert (Outlet Controls 1.02 cfs @ 1.30 fps) Summary for Pond 13P: 4'x4' FTIBC Filterra [87] Warning: Oscillations may require smaller dt or Finer Routing (severity=529) Inflow Area = 3,402 sf, 55.17% Impervious, Inflow Depth = 7.25" for 100-year event Inflow = 0.63 cfs @ 12.08 hrs, Volume= 2,055 cf Outflow = 0.63 cfs @ 12.09 hrs, Volume= 2,055 cf, Atten= 0%, Lag= 0.3 min Primary = 0.63 cfs @ 12.09 hrs, Volume= 2,055 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 195.10' @ 12.09 hrs Surf.Area= 16 sf Storage= 15 cf Flood Elev= 195.40' Surf.Area= 16 sf Storage= 16 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.5 min ( 782.4- 781.9) 4570-Postdrain-Rev1 Type 111 24-hr 100-year Rainfaii=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 0 2017 HydroCAD Software Solutions LLC Page 33 Volume Invert Avail.Storage Storage Description #1 194.19' 16 cf 4.00'W x 4.00'L x 1.00'H Prismatoid Device Routing Invert Outlet Devices #1 Primary 191.94' 6.0" Round Culvert L= 5.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 191.94'/ 191.84' S= 0.0200 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.20 sf #2 Device 1 194.19' 140.000 in/hr Exfiltration over Surface area #3 Device 1 194.73' 6.0" Horiz. Overflow Bypass C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=0.63 cfs @ 12.09 hrs HW=195.10' TW=193.15' (Dynamic Tailwater) L =Culvert (Passes 0.63 cfs of 1.32 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.05 cfs) 3 Overflow Bypass (Orifice Controls 0.58 cfs @ 2.93 fps) Summary for Pond 14P: 6'x8' FTIBC Filterra [87] Warning: Oscillations may require smaller dt or Finer Routing (severity=539) Inflow Area = 8,992 sf, 66.56% Impervious, Inflow Depth = 7.61" for 100-year event Inflow = 1.71 cfs @ 12.08 hrs, Volume= 5,705 cf Outflow = 1.71 cfs @ 12.09 hrs, Volume= 5,705 cf, Atten= 0%, Lag= 0.4 min Primary = 1.71 cfs @ 12.09 hrs, Volume= 5,705 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 194.28' @ 12.09 hrs Surf.Area=48 sf Storage=43 cf Flood Elev= 194.60' Surf.Area=48 sf Storage=48 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 0.5 min ( 773.7 - 773.1 ) Volume Invert Avail.Storage Storage Description #1 193.39' 48 cf 8.00'W x 6.00'L x 1.00'H Prismatoid Device Routing Invert Outlet Devices #1 Primary 191.14' 10.0" Round Culvert L= 70.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 191.14' / 190.43' S= 0.0101 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.55 sf #2 Device 1 193.39' 140.000 in/hr Exfiltration over Surface area #3 Device 1 193.93' 10.0" Horiz. Overflow Bypass C= 0.600 Limited to weir flow at low heads Primary OutFlow Max=1.71 cfs @ 12.09 hrs HW=194.28' TW=193.16' (Dynamic Tailwater) L =Culvert (Passes 1.71 cfs of 2.24 cfs potential flow) 2=Exfiltration (Exfiltration Controls 0.16 cfs) 3 Overflow Bypass (Orifice Controls 1.55 cfs @ 2.84 fps) 4670-Postdrain-Rev1 Type H/24-hr 100-year Rainfall=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCAD® 10 00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 34 Summary for Pond DMH1: PROP DMH-1 Inflow Area = 23,500 sf, 72.23% Impervious, Inflow Depth = 7.12" for 100-year event Inflow = 4.26 cfs @ 12.08 hrs, Volume= 13,937 cf Outflow = 4.26 cfs @ 12.08 hrs, Volume= 13,937 cf, Atten= 0%, Lag= 0.0 min Primary = 4.26 cfs @ 12.08 hrs, Volume= 13,937 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 192.59' @ 12.08 hrs Flood Elev= 195.20' Device Routing Invert Outlet Devices #1 Primary 189.76' 12.0" Round Culvert L= 23.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 189.76' / 189.31' S= 0.0196 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=4.25 cfs @ 12.08 hrs HW=192.58' TW=191.32' (Dynamic Tailwater) L1=Culvert (Inlet Controls 4.25 cfs @ 5.42 fps) Summary for Pond DMH2: PROP DMH-2 Inflow Area = 12,394 sf, 63.43% Impervious, Inflow Depth = 7.51" for 100-year event Inflow = 2.33 cfs @ 12.09 hrs, Volume= 7,761 cf Outflow = 2.33 cfs @ 12.09 hrs, Volume= 7,761 cf, Atten= 0%, Lag= 0.0 min Primary = 2.33 cfs @ 12.09 hrs, Volume= 7,761 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 193.19' @ 12.08 hrs Flood Elev= 195.90' Device Routing Invert Outlet Devices #1 Primary 190.33' 12.0" Round Culvert L= 95.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 190.33'/ 189.86' S= 0.0049 7' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=2.33 cfs @ 12.09 hrs HW=193.16' TW=192.54' (Dynamic Tailwater) t-1=Culvert (Outlet Controls 2.33 cfs @ 2.97 fps) Summary for Pond DMH3: PROP DMH-3 Inflow Area = 23,500 sf, 72.23% Impervious, Inflow Depth = 7.12" for 100-year event Inflow = 4.26 cfs @ 12.08 hrs, Volume= 13,937 cf Outflow = 4.26 cfs @ 12.08 hrs, Volume= 13,937 cf, Atten= 0%, Lag= 0.0 min Primary = 4.26 cfs @ 12.08 hrs, Volume= 13,937 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 191.32' @ 12.08 hrs Flood Elev= 194.10' 4570-Postdrain-Rev1 Type 111 24-hr 100-year Rainfall=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 0 2017 HydroCAD Software Solutions LLC Page 35 Device Routing Invert Outlet Devices #1 Primary 189.21' 12.0" Round Culvert L= 45.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 189.21' / 188.99' S= 0.0049 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=4.25 cfs @ 12.08 hrs HW=191.32' TW=0.00' (Dynamic Tailwater) t-1=Culvert (Barrel Controls 4.25 cfs @ 5.42 fps) Summary for Pond DMH4: PROP. DMH-4 Inflow Area = 11,106 sf, 82.05% Impervious, Inflow Depth = 6.67" for 100-year event Inflow = 1.98 cfs @ 12.06 hrs, Volume= 6,176 cf Outflow = 1.98 cfs @ 12.06 hrs, Volume= 6,176 cf, Atten= 0%, Lag= 0.0 min Primary = 1.98 cfs @ 12.06 hrs, Volume= 6,176 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 192.85' @ 12.08 hrs Flood Elev= 194.85' Device Routing Invert Outlet Devices #1 Primary 189.95' 12.0" Round Culvert L= 10.0' CPP, square edge headwall, Ke= 0.500 Inlet/Outlet Invert= 189.95' / 189.86' S= 0.0090 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf Primary OutFlow Max=1.98 cfs @ 12.06 hrs HW=192.78' TW=192.50' (Dynamic Tailwater) L1=Culvert (Inlet Controls 1.98 cfs @ 2.52 fps) Summary for Pond INFIL: U/G INFIL RAWL'S RATE OF 1.02in/hr USED FOR FINE SANDY LOAM Inflow Area = 3,565 sf,100.00% Impervious, Inflow Depth = 8.58" for 100-year event Inflow = 0.86 cfs @ 12.00 hrs, Volume= 2,549 cf Outflow = 0.84 cfs @ 12.01 hrs, Volume= 2,549 cf, Atten= 3%, Lag= 0.5 min Discarded = 0.02 cfs @ 12.01 hrs, Volume= 1,265 cf Primary = 0.83 cfs @ 12.01 hrs, Volume= 1,284 cf Routing by Dyn-Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.01 hrs/4 Peak Elev= 193.64' @ 12.01 hrs Surf.Area=433 sf Storage=405 cf Flood Elev= 194.33' Surf.Area=433 sf Storage= 528 cf Plug-Flow detention time= (not calculated: outflow precedes inflow) Center-of-Mass det. time= 125.4 min ( 859.9- 734.5) 4570-Postdrain-Revl Type III24-hr 100-year Rainfall=8.82" Prepared by Microsoft Printed 4/24/2019 HydroCADO 10 00-20 s/n 01710 ©2017 HydroCAD Software Solutions LLC Page 36 Volume Invert Avail.Storage Storage Description #1 A 192.00' 322 cf 8.17'W x 53.04%x 2.33'H Field A 1,011 cf Overall - 206 cf Embedded = 804 cf x 40.0%Voids #2A 192.50' 206 cf ADS_StormTech RC-310+Cap x 14 Inside#1 Effective Size= 28.9"W x 16.0"H => 2.07 sf x 7.121 = 14.7 cf Overall Size= 34.0"W x 16.0"H x 7.561 with 0.44' Overlap 2 Rows of 7 Chambers 528.cf Total Available Storage Storage Group A created with Chamber Wizard Device Routing Invert Outlet Devices #1 Discarded 192.00' 1.020 in/hr Exfiltration over Surface area Conductivity to Groundwater Elevation = 189.00' #2 Primary 190.10' 12.0" Round Culvert L= 12.0' CPP, square edge headwall, Ke= 0.500 Inlet/ Outlet Invert= 190.10'/ 189.95' S= 0.0125 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf #3 Device 2 193.45' 12.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads Qiscarded OutFlow Max=0.02 cfs @ 12.01 hrs HW=193.64' (Free Discharge) 1=Exfiltration ( Controls 0.02 cfs) Primary OutFlow Max=0.82 cfs @ 12.01 hrs HW=193.64' TW=191.80' (Dynamic Tailwater) L2=Culvert (Passes 0.82 cfs of 5.12 cfs potential flow) L3=Orifice/Grate (Weir Controls 0.82 cfs @ 1.41 fps) Appendix E Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc CONSTRUCTION PERIOD POLLUTION PREVENTION AND EROSION AND SEDIMENTATION CONTROL PLAN In accordance with DEP Stormwater Standard #8 the following is the construction period pollution prevention and erosion and sedimentation control plan for the Enterprise Bank Redevelopment project: Narrative Enterprise Bank is proposing to raze the existing 2-story veterinary building and demolish the associated paved parking& site features. The proposal is to redevelop the entire parcel into a new Enterprise Bank facility including a 3,250 square foot, 1-story building with drive-thru along with associated paved driveways, access aisles, 20 striped parking spaces, and a new trash enclosure. Site improvements also include new utility connects to existing services located within Chickering Road as well as a new stormwater management system. Construction Period Operation and Maintenance Plan Operation and maintenance of the construction period BMP's will be performed in accordance with this document, the Massachusetts Stormwater Handbook, the Nonpoint Source Manual, the US EPA Stormwater Best Management Practices and the Site Re-Development Plans. Name of Persons or Entities Responsible for Plan Compliance Enterprise Bank Construction Period Pollution Prevention Measures • Silt fence and hay bale barriers • Protection of soil stockpiles • Designated staging and material storage areas Erosion and Sedimentation Control Plan Drawings This information is included in the Site Re-Development Plans. Details and Specifications for Erosion Control BMP's This information is included in the Site Re-Development Plans. Vegetation Planning This information is included in the Site Re-Development Plans. Site Re-Development Plan This information is included in the Site Development Plans. \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\Construction Period Erosion and Sedimentation Control Plan-Revl.doc Construction Sequencing Plan 1. Install silt fence and haybale barriers 2. Remove existing site improvements that are not to remain 3. Cut and stump trees 4. Strip and stockpile topsoil 5. Excavate for footings for new structures 6. Bring site to subgrade 7. Install site utilities 8. Install pavement base courses 9. Finish grade all areas 10. Install finish course pavement 11. Install landscaping 12. Loam and seed all other disturbed areas 13. Remove sediment control barriers once permanent vegetation is established Sequencing of Erosion and Sedimentation Controls As outlined above and as detailed in the Site Re-Development Plans. Operation and Maintenance of Erosion and Sedimentation Controls Operation and maintenance of the erosion and sedimentation controls shall be performed by Enterprise Bank or their designee. Maintenance shall be performed as outlined on the Site Re- Development Plans. Inspection Schedule Inspection of the erosion and sedimentation controls shall be performed as outlined on the Site Re-Development Plans. Maintenance Schedule The maintenance schedule for the erosion and sedimentation controls shall be performed as outlined on the Site Re-Development Plans. Inspection and Maintenance Log Form A Construction Period Stormwater Operation and Log form is included on the following page. \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\Construction Period Erosion and Sedimentation Control Plan-Revl.doc Construction Period Stormwater Operation and Maintenance Log General Information Project Name Enterprise Bank,North Andover,MA Date of Inspection Start/End Time Inspector's Name(s) Inspector's Title(s) Inspector's Contact Information Describe present phase of construction Type of Inspection ❑ Regular ❑Post-storm event Weather Information Current Conditions: Do you suspect that discharges may have occurred since the last inspection? ❑Yes ❑No Are there any discharges at the time of inspection? ❑Yes ❑No Site-specific BMPs Temporary BMP Installed Corrective Action Needed Party contacted/ (Construction Phase) and Operating Method of contact BMP Description Properly? A Overall Site Construction ❑ Yes ❑No Activities B Silt Fence ❑Yes ❑No C Stockpiles ❑Yes ❑No \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev BConstruction Period Inspection Log Template.doc Page 1 of 3 Overall Site Issues BMP/activity Implemented? Maintained? Corrective Action Party contacted/ Method of contact I Are all slopes and disturbed ❑Yes ❑No ❑Yes ❑No areas not actively being worked properly stabilized? 2 Are natural resource areas ❑Yes ❑No [:]Yes ❑No (e.g.,streams,wetlands, mature trees,etc.)protected with barriers or similar BMPs? 3 Are perimeter controls and ❑ Yes [:]No ❑Yes ❑No sediment barriers adequately installed(keyed into substrate)and maintained? 4 Are discharge points and ❑ yes ❑No ❑Yes ❑No receiving waters free of sediment deposits? 5 Are storm drain inlets ❑Yes ❑No [:] Yes ❑No properly protected? 6 Is there evidence of ❑Yes ❑No ❑ Yes ❑No sediment being tracked into the street? 7 Is trash/litter fi-om work ❑ Yes ❑No ❑ Yes ❑No areas collected and placed in covered dumpsters? 8 Are washout facilities(e.g., ❑yes ❑No ❑ Yes ❑No paint,stucco,concrete) available,clearly marked, and maintained? 9 Are vehicle and equipment ❑Yes ❑No ❑Yes ❑No fueling,cleaning,and maintenance areas free of spills,leaks,or any other deleterious material? 10 Are materials that are ❑Yes ❑No ❑Yes ❑No potential stormwater contaminants stored inside or under cover? I I Are non-stormwater ❑ Yes ❑No ❑Yes ❑No discharges(e.g.,wash water, dewatering)properly controlled? \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev I\Construction Period Inspection Log Template.doc Page 2 of 3 Certification statement: "I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations." Print name: Signature: Date: Copies to: ❑ Owner: ❑ Contractor: ❑ Conservation Commission: ❑ MHF Project Manager: ❑ Other: \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\Construction Period Inspection Log Template.doc Page 3 of 3 Appendix F Illicit Discharge Statement \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\4570-Stormwater Report-Revl.doc NNININEENNIEW ® e 44 Stiles Road ° Suite One^ Salem, New Hampshire 03079 TEL (603) 893-0720 ^ FAX (603) 893-0733 MHF Design Consultants, Inc. www.mhfdesign.com March 13,2019 Town of North Andover Planning Board 120 Main Street North Andover,MA 01845 Re: 247 Chickering Road Map 46 Lot 4 Sub: Illicit Discharge Statement Standard#10 Dear Board Members: On behalf of our client, Enterprise Bank,we hereby state that to the best of our knowledge, no illicit discharges exist on the above referenced site and none are proposed with the site re-development plans. Implementing the pollution prevention plan measures outlined in the site redevelopment plans will prevent illicit discharges to the stormwater management system, including wastewater discharges and discharges of stormwater contaminated by contact with process wastes,raw materials,toxic pollutants, hazardous substances, oil, or grease. Refer to the Grading&Drainage Plan from the site plan set for additional information. Sincerely, MHF sign Consultants,Inc. -4'e4'10 Patrick W. McLaughlin, PE Project Engineer F:\Projects\Eng\439818\DRAINAGE\4398-Illicit Discharge Statement Standardl0.doc ENGINEERS 0 PLANNERS 0 SURVEYORS LEGEND , VGC VERTICAL GRANITE CURB CCB CAPE COD BERM DSLY DOUBLE SOLID LINE YELLOW SSLw SINGLE SOLID LINE WHITE GAS LINE w WATER LINE o 0 CHAIN LINK FENCE 0 o STOCKADE FENCE CONTOUR ELEVATION ti TREE UTILITY POLE < GUY WIRE OVERHEAD WIRE TREELINE �— SIGN RON ROD F_D 0.2' x� SPOT ELEVATION Q DRAIN MANHOLE ❑ CATCH BASIN SQ SEWER MANHOLE wv x D4 WATER VALVE WATER SHUT OFF FIRE HYDRANT 0 BOLLARD EM ELECTRIC METER �x LIGHT POLE C.O. PROP. CLEANOUT CB-1 ` (®; PROP. CATCH BASIN DMH-1 PROP. DRAIN MANHOLE PRO SMH-1 ;O; PROP. SEWER MANHOLE MEG MEET EXISTING GRADE PROP. SPOT ELEVATION — PROP. CONTOUR ELEVATION MAP 46 LOT 3 N/F 99 REMAINDER II LLC -A A PROP. SILT FENCE _ 3038 SIDCO DRIVE NASHVILLE, TN 37204 T.W. TOP OF WALL ELEV. BOOK 6552 PAGE 25 B.W. BOTTOM OF WALL ELEV. (RESIDENTIAL 3 DISTRICT) 04 PROP. GATE VALVE LEGEND VGC VERTICAL GRANITE CURB CCB CAPE COD BERM DsLY DOUBLE SOLID LINE YELLOW ssLw SINGLE SOLID LINE WHITE G GAS LINE w WATER LINE o 0 CHAIN LINK FENCE o o STOCKADE FENCE —90— - CONTOUR ELEVATION C TREE UTILITY POLE < GUY WIRE OVERHEAD WIRE TREELINE �- SIGN SPOT ELEVATION 0 DRAIN MANHOLE ❑ CATCH BASIN OS SEWER MANHOLE wv D4 m WATER VALVE 4& WATER SHUT OFF FIRE HYDRANT o BOLLARD EM ELECTRIC METER �x LIGHT POLE C.O. PROP. CLEANOUT CB-1 ;®; PROP. CATCH BASIN DMH-1 PROP. DRAIN MANHOLE PROPER SMH-1 O; PROP. SEWER MANHOLE MEG MEET EXISTING GRADE 331.25 PROP. SPOT ELEVATION PROP. CONTOUR ELEVATION MAP 46 LOT 3 N/F 99 REMAINDER II LLC PROP. SILT FENCE 3038 SIDCO DRIVE NASHVILLE, TN 37204 T.W. TOP OF WALL ELEV. BOOK 6552 PAGE 25 B.W. BOTTOM OF WALL ELEV. (RESIDENTIAL 3 DISTRICT) PROP. GATE VALVE WIN OPERATION MAINTENANCE PLAN and LONG TERM POLLUTION PREVENTION PLAN for STORMWATER MANAGEMENT SYSTEMS Enterprise Bank 247 Chickering Road North Andover, MA 01845 Prepared For: Enterprise Bank 222 Merrimack Street Lowell, MA 01852 March 13, 2019 Revised March 25, 2019 Revised April 24, 2019 MHF Project#457019 f 1 wr ( � WF a4 frI I ! h PAVER WAX114Y it S k i $ .r I °� i 1 'tr —FC STOCKADE. I ` MAP 46 LOT , 20.573 Ac.* _ !f WF 7A —_ 196.05 ei� I i I l,l. � .795.40 I t� EJ169�NG 1i1 ! 195.31 ` ; \ y_ OVE'nWWG(TYA.) )- ;'I I I � waXWAv \ 195,30 I ( t MAP 46 LOT 103 100'BUFFER ZONE N/F COBBLESTONEREALTYTRUSTCROSSING I) GRADE TO 4 7 COPIE CIRCLE t9s.so DRAIN(TYP) !I \ 4 y !WF NORTH ANDOVER. RC ot9a5 194. 194.75 �,` , I 195.10 BOOK 3925 PAGE 197NTIAL PRQP. FlL7ERRA (RESIDE 3 DISTRICT) MAP 46 LOT 3 d`II )17- ' 1196 UNIT)2(Fr-2) -.rrR J/F 99 REMAINDER II LLC ��I _ "" - I t94•60 I 195.86 i 1 3038 SIDCO DRIVE ! Q i 50' NO BUILD ZONE NASHVILLE TN 37204 a Z BOOK 6552 PAGE 25 ii I ,I 195.45 .a I �-`-WF 5A MAO NAIL II (RESIDENTIAL 3 DISTRICT? -- I 2-STp{^1 W 0 i ,1 24'71iEE FRAMED E AY 195.60 I /'F t ei L I F1EV.�198.97 BLI G 25' NO DISTURBANCE ZONE ��{I 195.84 �I 7,5'0. q. FalvtEo d..3xlrci t § z __.t PROPOSED 3,250 SF FF=, lased s=xEs rP.) a_I CATCH BASIN I' 1-STORY BANK 19150 \' @� ;0 52 a:. W.1 is — 1ae.00 W/ DRIVE THRU c FILTERRA UNIT �I GRADE CC CRE E '�`c) I -eu� 195.60 FF=796.50 POS@ _J• I� "I .Y� i,, .I-WF 4A�-IYETLANDS DELINEATED BY VIRONIMENTAL It{ UNDERGROUND 98 4 S�RNCESRSE NON dA U.4RY ` ROOF INFILTRATION 195.50 1 _ I t i IS 19 4 195.02 195.84 `' 'S,1j1) SYSTEM (SEE DETAIL) _ _ .GRADE w, } 30, 2079 BREAK 199. I L S Q c `J -- I y CONCRETE ` I e 195.38 i / �' WF 3A(REV) a YYY � S� L WF 3A H`:h'.'/ '1 °'l / i } ; k PROP. 196.30 - r "-_---- j —\ ROOF '' 1995.55 19&45 � � j t DRAIN-4 --= - ota a^' .. _1a7_ �. } REVISED FLAG LOCATIONS PER I�!F.SYSTEM 19560 °+ G - I / NORTH M:ffJ'rER CONSERVATION 195.70 `3aX - 1 COMMISSION AGENT AS OF APRI, 2019 / GRADE. 195.40 ./ WF 2A(R -�. WF to BREAK" : l DMH-2 \ f } ,s5 FIRST DEFENSE UNIT I !1 ' 1 c 194.30 „*7 \ i �. ...I .96` GRAD 4� �r `� q �..,` �> vI !CBCI 506 / — 195.80 yg \ _! a ,n' �: DMH-tJ PROP.FlLTERRA_ 4 196.10 .3", MPINAGE ENTS / ---- NIT#i (FT-1) NUl IN O PER PLAN �°jh MAG MAOUnU M POLE h REFERENCE/2 a f aN.-i Day _�Y _ _ ost,. q�' er01 53+00 PROP.DRAIN LINE - - - - - - - 5+00\ MODIFICATIONS HICKERING ROAD - ROUTE 1 13 _ (TO BE COORDINATED 9 Icoo PUBLIC - 80 WIDE - 1931 LAYOUT —J-- �----/---- ------ - ssu+• MASSOOT) _.-'- --. ( ) 508 �`' ------ -_ ---'---—- _ - - - - - - - - - - - - - - - - - - - - - - _ - - - --- - -- ---._.--- PROP. DMH -------- 4 w \ ;�I DMH 114VFRT"_'FtR.9R 505 -RC:1495.o: rtnv OPERATION & MAINTENANCE PLAN The property owner shall be responsible for the operation and maintenance of all stormwater management systems after construction in accordance with the below criteria. Logs of inspections and cleanings shall be maintained by the owner and annual BMP inspection forms shall be filed with the Town of North Andover, as required. As required and authorized by the property owner, representatives from the Planning Board, Conservation Commission or other authorized Town Agents may enter the property for inspection of the stormwater management system as needed. As required by the MassDEP Stormwater Management Handbook, which serves as guidance on the Massachusetts Stormwater Policy, and in accordance with Stormwater Standard #9, the following post construction operation and maintenance plan has been prepared. Stormwater Management System Owner: Enterprise Bank Owners Signature: Party or Parties Responsible for Operation and Maintenance: Enterprise Bank Routine and Non-Routine Maintenance Tasks: The following maintenance tasks will be performed as described below. Documentation: A maintenance log shall be kept summarizing inspections, maintenance and any corrective actions taken. The log shall include the date on which each inspection or maintenance task was performed, a description of the inspection findings or maintenance completed, and the name of the inspector or maintenance personnel performing the task. If a maintenance task requires the clean out of any sediments or debris, the location where the sediment and debris was disposed after removal will be indicated. Disposal of the accumulated sediment and hydrocarbons must be in accordance with applicable local, state, and federal guidelines and regulations. The logs shall be made accessible to the Town of North Andover upon request. Inspection and Maintenance Frequency and Corrective Measures: The following areas, facilities and measures will be inspected, and any identified deficiencies will be corrected. Clean out must include the removal and legal disposal of any accumulated sediments and debris in accordance with applicable local, state, and federal guidelines and regulations. 1. Parking Lot Sweeping Sweeping shall be done once in the early fall and then immediately following spring snowmelt to remove sand and other debris and any time when visual buildup of debris is apparent. At a minimum, the schedule for street sweeping shall be done quarterly with a high efficiency vacuum sweeper. Pavement surfaces shall be swept at other times such as in the fall after leaves have dropped to remove accumulated debris. Since contaminants typically accumulate within 12 inches of the curbline, sweeping operations should concentrate on cleaning curb and gutter lines for maximum pollutant removal. Once removed from paved surfaces, the sweepings must be handled \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\457019 Operation And Maintenance Manual-Rev2.Doc 2 and disposed of properly. Disposal of the accumulated sediment and hydrocarbons must be in accordance with applicable local, state, and federal guidelines and regulations. 2. Deep Sump Hooded Catch Basins Inspect catch basins at least 4 times per year including at the end of the foliage and snow removal seasons (late fall and early spring) to ensure that the catch basins are working in their intended fashion and that they are free of debris. Sediment must be removed whenever the depth of deposits is greater than or equal to one half the depth from the bottom of the invert of the lowest pipe in the basin. If the basin outlet is designed with a hood to trap floatable materials, check to ensure watertight seal is working. Damaged hoods shall be repaired or replaced. At a minimum, remove floating debris and hydrocarbons at the time of the inspection. Sediment and debris can be removed by a clamshell bucket; however a vacuum truck is preferred. Disposal of the accumulated sediment and hydrocarbons must be in accordance with applicable local, state, and federal guidelines and regulations. 3. Vegetated Areas Inspect slopes and embankments early in the growing season to identify active or potential erosion problems. Replant bare areas or areas with sparse growth. Where rill erosion is evident, armor the area with an appropriate lining or divert the erosive flows to on-site areas able to withstand the concentrated flows. 4. Snow Storage and Removal Proposed snow storage areas are show on the site plan. During the winter months all snow is to be stored such that snowmelt is controlled. In the event the amount of snow exceeds such capacity, it is to be removed off-site. The minimum amount of deicing chemicals needed is to be used. Do not dispose of snow on top of storm drain catch basins or in stormwater drainage swales or ditches. 5. Hydrodynamic Separator(First Defense Unit) Initial maintenance to be performed every six months for the first year after the unit is online and operational. A vacuum truck must be used at a minimum of once per year to remove floatables & sediment accumulation. Refer to the attached First Defense Owner's manual for operation and maintenance procedures and schedules thereafter. Additionally, the unit shall be inspected based on the below criteria: • Remove oil and floatables following a spill in the drainage areas. • Remove sediment following a spill in the drainage area. 6. Subsurface Stormwater Infiltration Systems All subsurface systems should initially be inspected within the first three months after completion of the site's construction. Preventive maintenance should be performed at least every six months and sediment shall be removed from pretreatment BMP's as necessary. The Infiltration System shall be inspected on regular bi-annual scheduled dates. During the first year of operation, the system shall be inspected after at least two large storm events (> 1 inch) to ensure that it is fully drained within 72 hours. If standing water is present more than 72 hours after a rainfall event, the infiltration system shall be cleaned. \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\457019 Operation And Maintenance Manual-ReQ.Doc 3 Ponded water in the system indicates potential infiltration failure in the bottom of the pipe and/or stone. In this case, accumulated sediment shall be removed from the bottom utilizing water jets and/or truck mounted vacuum equipment. Sediment and debris removal should be through the use of truck mounted vacuum equipment. Outlet pipes should be flushed to point of discharge on the same frequency as mentioned above. Disposal of the accumulated sediment and hydrocarbons must be in accordance with applicable local, state, and federal guidelines and regulations. The following is the recommended procedure to inspect the underground system in service: 1. Locate the riser or cleanout section of the system. The riser/cleanout will typically be 6 or 12" in diameter or larger. 2. Remove the lid from the riser/cleanout. 3. Measure the sediment buildup at each riser and cleanout location. Only certified confined space entry personnel having appropriate equipment should be permitted to enter the system. 4. Inspect each manifold, all laterals, and outlet pipes for sediment build up, obstructions, or other problems. Obstructions should be removed at this time. 5. If measured sediment build up is between 2" to 8", cleaning should be considered; if sediment build up exceeds 8", cleaning should be performed at the earliest opportunity. A thorough cleaning of the system (manifolds and laterals) shall be performed by water jets and/or truck mounted vacuum equipment. Pretreatment BMP's shall be inspected and cleaned during the regular bi-annual inspections. The inlet and outlet of the subsurface systems should be checked periodically to ensure that flow structures are not blocked by debris. All pipes connecting the structures to the system should be checked for debris that may obstruct flow. \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\457019 Operation And Maintenance Manual-RevlDoc 4 Long Term Pollution Prevention Plan In accordance with DEP Stormwater Standard #4 the development and implementation of suitable practices for source control and pollution prevention shall be incorporated in a Long Term Pollution Prevention Plan (LTPPP). The primary focus of the LTPPP is to establish procedures and controls for limiting the potential sources of pollutants, including nutrients that may contribute to excessive contaminant levels in the site's stormwater runoff. To this end the following source controls and procedures will be in place at the site: • Good House Keeping — It shall be the responsibility of the property owner to keep the site clean at all times. • Storing Material and waste products inside or under cover — No material storage is to take place on site. • Vehicle washing—Vehicle washing is not allowed to take place on premises. • Routine inspections and maintenance of stormwater BMP's —Refer to the Operation and Maintenance procedures for each BMP as described in the O&M Plan. • Maintenance of lawns, gardens and other landscaped areas — All landscaping and maintenance to be performed by an authorized company chosen by the property owner. • Storage and use of fertilizers, herbicides and pesticides —All landscape maintenance will be conducted by an authorized company chosen by the property owner. Any application of herbicides or pesticides will be applied by a licensed applicator. There will be no on-site storage of fertilizers, herbicides and pesticides. • Proper management of deicing chemicals and snow — Deicing chemicals and snow removal shall be conducted by an authorized company chosen by the property owner. • Nutrient management plan- The goal of the nutrient management plan is to minimize the potential sources of excess nutrients on the site and the release of nutrients in the stormwater from the site. In general, the nature of the site use will tend to reduce the nutrients in the stormwater. Further,procedures indicated above or in the O&M Plan related BMP maintenance procedures, and street sweeping will act to reduce the levels of nutrients in the stormwater, and the nutrients entering the adjacent wetland and the groundwater. \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\457019 Operation And Maintenance Manual-RevlDoc 5 Construction Period Stormwater Operation and Maintenance Log General Information Project Name Enterprise Bank,North Andover,MA Date of Inspection Start/End Time Inspector's Name(s) Inspector's Title(s) Inspector's Contact Information Describe present phase of construction Type of Inspection ❑Regular ❑Post-storm event Weather Information Current Conditions: Do you suspect that discharges may have occurred since the last inspection? ❑Yes ❑No Are there any discharges at the time of inspection? ❑ Yes ❑No Site-specific BMPs Temporary BMP Installed Corrective Action Needed Party contacted/ (Construction Phase) and Operating Method of contact BMP Description Properly? A Overall Site Construction ❑Yes ❑No Activities B Silt Fence ❑ Yes [:]No C Stockpiles ❑Yes ❑No \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\Construction Period Inspection Log Template.doc Page I of 3 Overall Site Issues BMP/activity Implemented? Maintained? Corrective Action Party contacted/ Method of contact I Are all slopes and disturbed ❑Yes ❑No ❑Yes ❑No areas not actively being worked properly stabilized? 2 Are natural resource areas ❑ Yes [—]No ❑Yes ❑No (e.g.,streams,wetlands, mature trees,etc.)protected with barriers or similar BMPs? 3 Are perimeter controls and ❑Yes ❑No ❑Yes ❑No sediment barriers adequately installed(keyed into substrate)and maintained? 4 Are discharge points and ❑Yes ❑No ❑Yes ❑No receiving waters free of sediment deposits? 5 Are storm drain inlets ❑ Yes ❑No ❑Yes ❑No properly protected? 6 Is there evidence of ❑Yes ❑No ❑ Yes ❑No sediment being tracked into the street? 7 Is trash/litter from work ❑Yes ❑No ❑Yes ❑No areas collected and placed in covered dumpsters? 8 Are washout facilities(e.g., ❑ Yes ❑No ❑Yes ❑No paint,stucco,concrete) available, clearly marked, and maintained? 9 Are vehicle and equipment ❑yes [—]No ❑Yes ❑No fueling,cleaning,and maintenance areas free of spills, leaks,or any other deleterious material? 10 Are materials that are ❑ Yes ❑No ❑ Yes ❑No potential stormwater contaminants stored inside or under cover? I 1 Are non-stormwater ❑Yes ❑No ❑Yes ❑No discharges(e.g.,wash water, dewatering)properly controlled? \\ IFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\Construction Period Inspection Log Template.doc Page 2 of 3 Certification statement: "I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations." Print name: Signature: Date: Copies to: ❑ Owner: ❑ Contractor: ❑ Conservation Commission: ❑ MHF Project Manager: ❑ Other: \\MFS\Company_Data\Projects\Eng\457019\Drainage\Rev 1\Construction Period Inspection Log Template.doc Page 3 of 3 Hydro International F , �r d Operation and Maintenance Manual First Defense°and First Defense°-Hc Stormwater Solutions Vortex Separator for Stormwater Treatment Turning Water Around ...® Page 12 First Defense°Operation and Maintenance Manual Table of Contents 3 First Defense®by Hydro International -Introduction -Operation -Pollutant Capture and Retention 4 Model Sizes&Configurations -First Defense®Components 5 Maintenance -Overview -Maintenance Equipment Considerations -Determining Your Maintenance Schedule 6 Maintenance Procedures -Inspection -Floatables and Sediment Clean Out 8 First Defense®Installation Log 9 First Defense®Inspection and Maintenance Log COPYRIGHT STATEMENT:The contents of this manual, including the graphics contained herein, are intended for the use of the recipient to whom the document and all associated information are directed. Hydro International plc owns the copyright of this document,which is supplied in confidence. It must not be used for any purpose other than that for which it is supplied and must not be reproduced,in whole or in part stored in a retrieval system or transmitted in any form or by any means without prior permission in writing from Hydro International plc. First Defense®is a trademarked hydrodynamic vortex separation device of Hydro International plc.A patent covering the First Defense®has been granted. DISCLAIMER: Information and data contained in this manual is exclusively for the purpose of assisting in the operation and maintenance of Hydro International pic's First Defense®.No warranty is given nor can liability be accepted for use of this information for any other purpose.Hydro International plc has a policy of continuous product development and reserves the right to amend specifications without notice. Hydro International(Stormwater), 94 Hutchins Drive, Portland ME 04102 Tel: (207)756-6200 Fax: (207)756-6212 Web:www.hydro-int.com Page 13 First Defense®Operation and Maintenance Manual I. First Defense° by Hydro International Introduction Applications The First Defense® is an enhanced vortex separator •Stormwater treatment at the point of entry into the drainage line that combines an effective and economical stormwater •Sites constrained by space,topography or drainage profiles treatment chamber with an integral peak flow bypass. It with limited slope and depth of cover efficiently removes total suspended solids (TSS), trash and •Retrofit installations where stormwater treatment is placed on or hydrocarbons from stormwater runoff without washing out tied into an existing storm drain line previously captured pollutants.The First Defense®is available • Pretreatment for filters, infiltration and storage in several model configurations (refer to Section ll. Model Sizes & Configurations, page 4) to accommodate a wide Advantages range of pipe sizes, peak flows and depth constraints. • Inlet options include surface grate or multiple inlet pipes • Integral high capacity bypass conveys large peak flows without the need for"offline"arrangements using separate junction Operation manholes The First Defense®operates on simple fluid hydraulics. It is self- •Proven to prevent pollutant washout at up to 500%of its activating,has no moving parts,no external power requirement treatment flow and is fabricated with durable non-corrosive components. • Long flow path through the device ensures a long residence No manual procedures are required to operate the unit and time within the treatment chamber, enhancing pollutant settling maintenance is limited to monitoring accumulations of stored • Delivered to site pre-assembled and ready for installation pollutants and periodic clean-outs. The First Defense® has been designed to allow for easy and safe access for inspection, monitoring and clean-out procedures. Neither entry into the unit nor removal of the internal components is necessary for maintenance,thus safety concerns related to confined-space- entry are avoided. Pollutant Capture and Retention r The internal components of the First Defense® have been designed to optimize pollutant capture. Sediment is captured � �� and retained in the base of the unit, while oil and floatables t are stored on the water surface in the inner volume(Fig.1). The pollutant storage volumes are isolated from the built-in Oil Max oil Storage Depth bypass chamber to prevent washout during high-flow storm events. The sump of the First Defense® retains a standing water level between storm events. This ensures a quiescent flow regime at the onset of a storm, preventing resuspension and washout of pollutants captured during previous events. Sediment Sediment Storage Accessories such as oil absorbent pads are available for enhanced oil removal and storage. Due to the separation of the oil and floatable storage volume from the outlet, the potential for washout of stored pollutants between clean-outs Fig.1 Pollutant storage volumes in the First Defense®. is minimized. Page 14 First Defense®Operation and Maintenance Manual II. Model Sizes & Configurations The First Defense®inlet and internal bypass arrangements are available in several model sizes and configurations.The components of the First Defense0-4HC and First Defense®-6HC have modified geometries as to allow greater design flexibility needed to accommodate various site constraints. All First Defense'models include the internal components that are designed to remove and retain total suspended solids(TSS), gross solids, floatable trash and hydrocarbons (Fig.2a - 2b). First Defense® model parameters and design criteria are shown in Table 1. First Defense° Components 1. Built-in Bypass 4. Floatables Draw-off Port 7. Sediment Storage 2. Inlet Pipe 5. Outlet Pipe 8. Inlet Grate or Cover 3. Inlet Chute 6. Floatables Storage (not pictured) r a. b. Fig.2a)First Defense®-4 and First Defense®-6,b)First Defense®-4HC and First Defense®-6HC, with higher capacity dual internal bypass and larger maximum pipe diameter. Table 1. First Defense®Pollutant Storage Capacities and Maximum Clean out Depths 00' 0- 0. 0 0 FD-4 180/681 <23.5/60 4/1.2 1.3/1.0 33/84 0.7/0.5 18/46 FD-4HC 191 /723 <24.4/62 FD-6 420/1,590 <23.5/60 6 /1.8 3.3/2.5 37.5/95 1.3/1.0 15/38 FD-6HC 496/1,878 <28.2/72 NOTE Sediment storage capacity and clean out depth may vary, as larger sediment storage sump volumes are provided when required. Hydro International(Stormwater), 94 Hutchins Drive, Portland ME 04102 Tel: (207)756-6200 Fax: (207)756-6212 Web:www.hydro-int.com Page 15 First Defense®Operation and Maintenance Manual III. Maintenance Overview The First Defense®protects the environment by removing a wide range of pollutants from stormwater runoff. Periodic removal of these captured pollutants is essential to the continuous,long-term functioning of the First Defense®. The First Defense'will capture and retain sediment and oil until the sediment and oil storage volumes are full to capacity. When sediment and oil storage capacities are reached,the First Defense®will no longer be able to store removed sediment and oil. Maximum pollutant storage capacities are provided in Table 1. The First Defense"allows for easy and safe inspection, monitoring and clean-out procedures. A commercially or municipally owned sump-vac is used to remove captured sediment and floatables. Access ports are located in the top of the manhole. Maintenance events may include Inspection,Oil&Floatables Removal,and Sediment Removal. Maintenance events do not require entry into the First Defense®, nor do they require the internal components of the First Defense®to be removed. In the case of inspection and floatables removal,a vactor truck is not required. However, a vactor truck is required if the maintenance event is to include oil removal and/or sediment removal. Maintenance Equipment Considerations The internal components of the First Defense®-HC have a centrally located circular shaft through which the sediment storage sump can be accessed with a sump vac hose.The open diameter of this access shaft is 15 inches in diameter(Fig.3).Therefore,the nozzle fitting of any vactor hose used for maintenance should be less than 15 inches in diameter. 15-in Maintenance Access tl �d Fig.3 The central opening to the sump of the First Defense LHC is 15 inches in diameter. Determining Your Maintenance Schedule The frequency of clean out is determined in the field after installation. During the first year of operation,the unit should be inspected every six months to determine the rate of sediment and floatables accumulation. A simple probe such as a Sludge-Judge®can be used to determine the level of accumulated solids stored in the sump. This information can be recorded in the maintenance log(see page 9)to establish a routine maintenance schedule. The vactor procedure,including both sediment and oil/flotables removal,for a 6-ft First Defense®typically takes less than 30 minutes and removes a combined water/oil volume of about 765 gallons. 7710 �mr Page 16 First Defense'Operation and Maintenance Manual Inspection Procedures 1. Set up any necessary safety equipment around the access port or grate of the First Defense®as stipulated by local ordinances. Safety equipment should notify passing pedestrian and road traffic that work is being done. 2. Remove the grate or lid to the manhole. 3. Without entering the vessel, look down into the chamber to inspect the inside. Make note of any irregularities. Fig.4 shows the standing water level that should be observed. y 4. Without entering the vessel, use the pole with the skimmer net to remove floatables and loose debris from the components and water surface. 5. Using a sediment probe such as a Sludge Judge®, measure � , the depth of sediment that has collected in the sump of the i vessel. 6. On the Maintenance Log(see page 9), record the date, unit , location, estimated volume of floatables and gross debris removed, and the depth of sediment measured. Also note any apparent irregularities such as damaged components or blockages. 7. Securely replace the grate or lid. i 8. Take down safety equipment. 9. Notify Hydro International of any irregularities noted during - inspection. Fig.4 Floatables are removed with a vactor hose(First Defense model FD-4, shown). Floatables and Sediment Clean Out Floatables clean out is typically done in conjunction with Recommended Equipment sediment removal. A commercially or municipally owned sump- . Safety Equipment(traffic cones, etc) vac is used to remove captured sediment and floatables(Fig.5). • Crow bar or other tool to remove grate or lid Floatables and loose debris can also be netted with a skimmer and pole. The access port located at the top of the manhole . Pole with skimmer or net(if only floatables are being removed) provides unobstructed access for a vactor hose and skimmer pole to be lowered to the base of the sump. • Sediment probe(such as a Sludge Judge®) Scheduling • Vactor truck(flexible hose recommended) • Floatables and sump clean out are typically conducted once a year during any season. • First Defense®Maintenance Log • Floatables and sump clean out should occur as soon as possible following a spill in the contributing drainage area. Hydro International(Stormwater), 94 Hutchins Drive, Portland ME 04102 Tel: (207)756-6200 Fax: (207)756-6212 Web:www.hydro-int.com Page 17 First Defense®Operation and Maintenance Manual Floatables and sediment Clean Out Procedures 1. Set up any necessary safety equipment around the access port or grate of the First Defense®as stipulated by local ordinances. Safety equipment should notify passing pedestrian and road traffic that work is being done. 2. Remove the grate or lid to the manhole. 3. Without entering the vessel, look down into the chamber to inspect the inside. Make note of any irregularities. f 4. Remove oil and floatables stored on the surface of the water with the vactor hose(Fig.5)or with the skimmer or net(not ' f;, a pictured). 5. Using a sediment probe such as a Sludge Judge®, measure r �� the depth of sediment that has collected in the sump of the a' vessel and record it in the Maintenance Log (page 9). 6. Once all floatables have been removed,drop the vactor hose to the base of the sump. Vactor out the sediment and gross debris off the sump floor(Fig.5). i �f 7. Retract the vactor hose from the vessel. % 8. On the Maintenance Log provided by Hydro International, record the date, unit location, estimated volume of floatables and gross debris removed,and the depth of sediment measured. Also note any apparent irregularities such as . damaged components, blockages, or irregularly high or low water levels. Fig.5 Sediment is removed with a vactor hose(First Defense model FD-4, shown). 9. Securely replace the grate or lid. Maintenance at a Glance illi-I NO le'llillIllij:11111111; ;1 11 MINES, .® Inspection -Regularly during first year of installation -Every 6 months after the first year of installation Oil and Floatables -Once per year,with sediment removal Removal -Following a spill in the drainage area Sediment Removal -Once per year or as needed - Following a spill in the drainage area NOTE: For most clean outs the entire volume of liquid does not need to be removed from the manhole. Only remove the first few inches of oils and floatables from the water surface to reduce the total volume of liquid removed during a clean out. Hyoro'm International First Defense® Installation Log HYDRO INTERNATIONAL REFERENCE NUMBER: SITE NAME: SITE LOCATION. OWNER: CONTRACTOR: CONTACT NAME: CONTACT NAME: COMPANY NAME: COMPANY NAME: ADDRESS: ADDRESS: TELEPHONE: TELEPHONE: FAX: FAX: INSTALLATION DATE: MODEL SIZE (CIRCLE ONE): FD-4 FD-4HC FD-6 FD-6HC INLET(CIRCLE ALL THAT APPLY): GRATED INLET(CATCH BASIN) INLET PIPE (FLOW THROUGH) Hydro International (Stormwater),94 Hutchins Drive, Portland ME 04102 Tel: (207)756-6200 Fax: (207)756-6212 Web:www.hydro-int.com � � InternationalHydro First Defense° Inspection and Maintenance Log Date Initials Depth of Sediment Volume of Site Activity and Floatables Depth Sediment Comments and Oils Measured Removed Hydro International (Stormwater), 94 Hutchins Drive, Portland ME 04102 Tel: (207)756-6200 Fax: (207)756-6212 Web:www.hydro-int.com 's w Hydro International (Stormwater), 94 Hutchins Drive, Portland ME 04102 Tel: (207)756-6200 Fax: (207)756-6212 Web:www.hydro-int.com Notes