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Ferris Junkyard SPR Stormwater Pln I lo , Ig , 2c�� cenk[��1 �R�'iS �Jr�K�c�Rc� SP12 li r Stormwater - Management 1 Plan x J14 under the ! Massachusetts Stormwater Management Regulations 1 ! Residential Development 16, 18, & 20R Franklin Street Salem, MA August 2017 Applicant: 1 Juniper Point Investment Company, LLC Submitted to. DVED 1 � City of Salem, MA • �' 3120117 4w f ��T " PLANNING & ' COMMUNfTY DEVELOPMENT Prepared by.- Griffin Engineering ' Beverly, MA TABLE OF CONTENTS Stormwater Management Checklist Attachment A Project Description 1.0 INTRODUCTION ............................................................................................................A-1 ' 1.1 Existing Conditions................................................................................................A-1 1.2 Proposed Conditions.............................................................................................A-2 ' 2.0 STORMWATER MANAGEMENT STANDARDS ...........................................................A-3 2.1 Standard 1: No New Untreated Discharges...........................................................A-3 2.2 Standard 2: Peak Rate Attenuation .......................................................................A-3 2.3 Standard 3: Recharge ...........................................................................................A-3 2.4 Standard 4: Water Quality.....................................................................................A-4 2.5 Standard 5: Land Uses With Higher Potential Pollutant Loads ..............................A-4 2.6 Standard 6: Critical Areas......................................................................................A-4 ' 2.7 Standard 7: Redevelopment Projects and Other Projects Subject to the Standards only to the Maximum Extent Practicable..................A-5 2.8 Standard 8: Construction Period Pollution Prevention and Erosion and Sediment Control......................................................................A-5 2.9 Standard 9: Operation and Maintenance Plan.......................................................A-6 ' 2.10 Standard 10: Prohibition of Illicit Discharges........................................................A-6 3.0 SUMMARY.....................................................................................................................A-6 Attachment B Stormwater Computations B.1 -Water Quality Volume Calculations B.2 -Water Quality Flow Calculations ' B.3 -Test Borings August 2013 by SP Engineering, Inc BA -TSS Removal Calculation Worksheets B.5 -TSS Removal Efficiency Curve ' (by Hydro International) Attachment C Long-Term Pollution Prevention Plan ' Attachment D Operation and Maintenance Plan ' Attachment E Illicit Discharge Statement Attachment F Proprietary Separator Third-Party Evaluation STORMWATER MANAGEMENT CHECKLIST 1 1 ' Ma ssachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program Checklist for Stormwater Report 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, the Stormwater Report which should provide more substantive and detailed information but is offered use only the tab 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. i ' 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. t2 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. Stormwater-Checklist.doc-04/01/08 Stormwater Report Checklist•Page 1 of 8 1 Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program 1 Checklist for Stormwater Report 1 B. Stormwater Checklist and Certification The following checklist is intended to serve as a guide for applicants as to the elements that ordinarily 1 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. 1 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 1 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 1 Engineer who prepared the Stormwater Report. Registered Professional Engineer's Certification 1 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 1 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 1 Stormwater Report accurately reflects conditions at the site as of the date of this permit application. Registered Professional Engineer Block and Signature 1 1NOFM qss O=1 ROBERT G H. m o GRIFFIN y CIVIL #36686 1 a�7 1 Signature and Date ' Checklist Project Type: Is the application for new development, redevelopment, or a mix of new and ' redevelopment? ❑ New development ❑ Redevelopment ® Mix of New Development and Redevelopment Stormwater-Checklist.doc•04/01/08 Stormwater Report Checklist-Page 2 of 8 1 1 Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program 1Ll Checklist for Stormwater Report 1 Checklist (continued) LID Measures: Stormwater Standards require LID measures to be considered. Document what 1 environmentally sensitive design and LID Techniques were considered during the planning and design of the project: 1 ❑ No disturbance to any Wetland Resource Areas ® Site Design Practices(e.g. clustered development, reduced frontage setbacks) 1 ® Reduced Impervious Area (Redevelopment Only) ❑ Minimizing disturbance to existing trees and shrubs 1 ❑ LID Site Design Credit Requested: 1 ❑ Credit 1 ❑ Credit 2 1 ❑ Credit 3 ❑ Use of"country drainage"versus curb and gutter conveyance and pipe 1 ❑ Bioretention Cells(includes Rain Gardens) 1 ❑ Constructed Stormwater Wetlands (includes Gravel Wetlands designs) ❑ Treebox Filter 1 ❑ Water Quality Swale ❑ Grass Channel 1 ❑ Green Roof 1 ❑ Other(describe): 1 Standard 1: No New Untreated Discharges ® No new untreated discharges 1 ® 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. Stormwater-Checklist.doc-04/01/08 Stormwater Report Checklist-Page 3 of 8 1 1 Massachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program 1Ll Checklist for Stormwater Report 1 Checklist (continued) Standard 2: Peak Rate Attenuation 1 ® 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. 1 ❑ 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. 1 Standard 3: Recharge 1 ❑ Soil Analysis provided. ❑ Required Recharge Volume calculation provided.- No rtckwv +row _av� ko s. e sn;\z �01\ ❑ 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. 1 ❑ Static ❑ Simple Dynamic ❑ Dynamic Field' 1 ❑ 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 1 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. 1 ® Recharge BMPs have been sized to infiltrate the Required Recharge Volume only to the maximum extent practicable for the following reason: 1 ® 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 1 ® Solid Waste Landfill pursuant to 310 CMR 19.000 ❑ Project is otherwise subject to Stormwater Management Standards only to the maximum extent ' practicable. ❑ Calculations showing that the infiltration BMPs will drain in 72 hours are provided. ' ❑ Property includes a M.G.L. c. 21E site or a solid waste landfill and a mounding analysis is included. 80%TSS removal is required prior to discharge to infiltration BMP if Dynamic Field method is used. Stormwater-Checklist.doc•04/01/08 Stormwater Report Checklist•Page 4 of 8 1 1 Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program 1Ll Checklist for Stormwater Report 1 Checklist (continued) Standard 3: Recharge(continued) 1 ❑ 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 1 analysis is provided. ❑ Documentation is provided showing that infiltration BMPs do not adversely impact nearby wetland resource areas. ' 1 Standard 4:Water Quality The Long-Term Pollution Prevention Plan typically includes the following: 1 Good housekeeping practices; • Provisions for storing materials and waste products inside or under cover; • Vehicle washing controls; 1 Requirements for routine inspections and maintenance of stormwater BMPs; • Spill prevention and response plans; • Provisions for maintenance of lawns, gardens, and other landscaped areas; 1 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; 1 Snow disposal and plowing plans relative to Wetland Resource Areas; • Winter Road Salt and/or Sand Use and Storage restrictions; • Street sweeping schedules; 1 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; 1 • 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 1 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: 1 ❑ is within the Zone II or Interim Wellhead Protection Area ❑ is near or to other critical areas 1 ❑ 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. Stormwater-Checklist.doc•04/01/08 Stormwater Report Checklist•Page 5 of 8 1 LIMassachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program 1 Checklist for Stormwater Report ' 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 ® Q q tY provided showing that the BMP treats the required water quality volume. I ' ® 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. t Stormwater-Checklist.doc-04/01/08 Stormwater Report Checklist-Page 6 of 8 1 ' Massachusetts Department of Environmental Protection LJ Bureau of Resource Protection -Wetlands Program Checklist for Stormwater Report ' Checklist (continued) Standard 7: Redevelopments and Other Projects Subject to the Standards only to the maximum extent practicable ® The project is subject to the Stormwater Management Standards only to the maximum Extent Practicable as a: ' ❑ Limited Project ❑ Small Residential Projects: 5-9 single family houses or 5-9 units in a multi-family development provided there is no discharge that may potentially affect a critical area. ❑ Small Residential Projects: 2-4 single family houses or 2-4 units in a multi-family development with a discharge to a critical area ❑ Marina and/or boatyard provided the hull painting, service and maintenance areas are protected ' from exposure to rain, snow, snow melt and runoff ❑ Bike Path and/or Foot Path ❑ Redevelopment Project ® Redevelopment portion of mix of new and redevelopment. ' ® Certain standards are not fully met(Standard No. 1, 8, 9, and 10 must always be fully met)and an explanation of why these standards are not met is contained in the Stormwater Report. ® The project involves redevelopment and a description of all measures that have been taken to improve existing conditions is provided in the Stormwater Report. The redevelopment checklist found in Volume 2 Chapter 3 of the Massachusetts Stormwater Handbook may be used to document that the proposed stormwater management system (a)complies with Standards 2, 3 and the pretreatment and structural BMP requirements of Standards 4-6 to the maximum extent practicable and (b) ' improves existing conditions. Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control ' A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan must include the following information: • Narrative; • Construction Period Operation and Maintenance Plan; • Names of Persons or Entity Responsible for Plan Compliance; • Construction Period Pollution Prevention Measures; • Erosion and Sedimentation Control Plan Drawings; • Detail drawings and specifications for erosion control BMPs, including sizing calculations; • Vegetation Planning; ' • Site Development Plan; • Construction Sequencing Plan; • Sequencing of Erosion and Sedimentation Controls; ' • Operation and Maintenance of Erosion and Sedimentation Controls; • Inspection Schedule; • Maintenance Schedule; ' Inspection and Maintenance Log Form. ® A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan containing the information set forth above has been included in the Stormwater Report. Stormwater-Checklist.doc•04/01/08 Stormwater Report Checklist•Page 7 of 8 1 Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program 1 Checklist for Stormwater Report 1 Checklist (continued) Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control 1 (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 1 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. 1 ❑ 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 1 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. 1 Standard 9: Operation and Maintenance Plan ® The Post Construction Operation and Maintenance Plan is included in the Stormwater Report and includes the following information: 1 ® Name of the stormwater management system owners; ® Party responsible for operation and maintenance; 1 ® Schedule for implementation of routine and non-routine maintenance tasks; 1 ® Plan showing the location of all stormwater BMPs maintenance access areas; ® Description and delineation of public safety features; 1 ® Estimated operation and maintenance budget; and ® Operation and Maintenance Log Form. 1 ❑ The responsible party is not the owner of the parcel where the BM is located and the Stormwater Report includes the following submissions: 1 ❑ 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 1 ® The Long-Term Pollution Prevention Plan includes measures to prevent illicit discharges; ❑ An Illicit Discharge Compliance Statement is attached; 1 ® NO Illicit Discharge Compliance Statement is attached but will be submitted prior to the discharge of any stormwater to post-construction BMPs. Stormwater-Checklist.doc-04/01/08 Stormwater Report Checklist•Page 8 of 8 ' ATTACHMENT A ' PROJECT ' DESCRIPTION 1 ' 1.0 INTRODUCTION i ' This stormwater management report is prepared in support of the proposed site redevelopment and construction of a residential development at 16, 18, and 20R Franklin Street in Salem, MA. The drainage system has been designed in accordance with the Massachusetts Department of Environmental Protection (MassDEP) Stormwater Management Standards. 1.1 Existing Conditions The site is approximately 2.27-acres in size and is made up of three parcels. The project site has been used for automobile fueling, servicing and the Ferris Junkyard tsince the mid-1950's. The October 2013 Environmental Site Assessment (ESA) by SP Engineering, Inc.' states that the property was a municipal landfill prior to becoming a junkyard and that the site is largely filled tidelands. The landfill use is ' also described as occupying fifty-percent or more of the property and the adjacent park (Furlong Park; owned by the City of Salem); and was operated by the City of Salem between approximately 1906 and 1930. The landfill received wastes such as municipal ash, demolition debris, and leather wastes. ' The adjacent Furlong Park was remediated by the City of Salem as part of park improvements in approximately 2010. A Release Abatement Measure Plan (RAM) was submitted in February 2011 for park remediation under DEP Release Tracking Number (RTN) 3-29262.2 1 The site primarily has a gravel and dirt surface with little vegetation present. Some t on-site roadways are paved. The extent of pavement within the junkyard could not be precisely determined due to the stored vehicles. We estimated that 25% of the interior area was pavement. Mature deciduous trees (ash, oak, maple, and locust) ' exist along the southern property boundary and within the parcel near the northern parcel boundary. ' Stored vehicles were removed a few years ago from the approximately 50-ft wide strip of land along the North River. That area is now sparsely vegetated with grasses and weeds. A one-story garage and office structure is located on the west side of the project site adjacent to Franklin Street. The topography of the site is relatively level terrain with only two feet of grade ' change across the site above the coastal bank. The highest point lies at the northwest corner of the site which drains southeast towards the North River. A soil Phase Two Environmental Site Assessment at 18 Franklin Street, Salem,MA prepared by SP Engineering, Inc. of Salem,MA. October 2013. 2 Release Abatement Measure Plan for Furlong Park Soil Excavation and Removal at 20 Franklin Street, Salem MA prepared by TRC Environmental Corporation of Lowell,MA dated February 2011 (Mass DEP RTN 3- 29262). A-1 ' berm along the North River bank appears to prevent junkyard runoff from draining directly into the river. The FEMA Firm Flood Map shows that the site is located within a Zone "AU Flood Hazard area (Elevation 10-ft; NAVD 1988 datum, reference: FEMA FIRM Map No. ' 25009CO419G dated July 16, 2014). Zone "AE" Flood Hazards are defined as areas subject to inundation by the 100-year flood event, with known base flood elevations. The entire property is located within the AE flood zone. 1.2 Proposed Conditions The project involves redevelopment of the junkyard site located along the North ' River on the south side of Franklin Street between Furlong Park and the Burnham Dredging Company operation at 14 Franklin Street. The plans call for construction of six buildings —five residential structures and a garage structure— providing a total ' of 43 dwelling units. The proposed project includes site remediation as directed by the project Licensed Site Profession, and complete removal of the Ferris Junkyard and associated car repair and maintenance facilities within the property. Near the residential buildings, a gazebo, landscaping and on-site parking will be installed. The proposed project also includes construction of a public access walkway and ' landscaping along the North River waterfront. Site plans showing the proposed redevelopment and stormwater management system have been separately provided. ' The proposed project is a mixture of new development and redevelopment. When complete, there will be approximately 46,040 square feet of impervious surfaces at the site. This exceeds the current amount of impervious surfaces (26,480 square ' feet) by approximately 19,560 square feet. In other words, approximately 43% of the site impervious surfaces are considered "new" development and 57% are ' considered redevelopment. Stormwater runoff from the "new" development area will fully meet all 10 DEP Stormwater Management Standards except standard 3 (recharge). The project intentionally does not include a recharge component due to ' the site landfill and junkyard history. Stormwater runoff from the redevelopment portion of the site will meet the DEP Stormwater Standards to the maximum extent practicable. tThe proposed project significantly improves existing drainage conditions by capturing and treating runoff from approximately 81% of the proposed walkways and ' parking area (16,960 sq. ft.) prior to discharging to the municipal drainage pipe that discharges to the North River. Runoff from the proposed building roofs (25,000± sq. ft.) is considered clean and does not require treatment. Roof runoff is directed away ' from the municipal drain line where practicable. Approximately 91% of the impervious surfaces on-site are in full compliance with the Standards (except Standard 3, for reasons described above), which exceeds the requirement for ' redevelopment at this site. A-2 2.0 STORMWATER MANAGEMENT STANDARDS 2.1 Standard 1: No New Untreated Discharges No new untreated discharges to wetlands or waterways are proposed. ' 2.2 Standard 2: Peak Rate Attenuation A waiver from Standard 2 applies because the project is located in land subject to coastal storm flowage; the stormwater discharge is to the tidal North River. 2.3 Standard 3: Recharge tThe United States Department of Agriculture Natural Resources Conservation Service Soil Survey characterizes the soil as Urban Land, which indicates that the soils have been significantly altered or obscured by urban works and structures. Four soil borings installed in August 2013 by SP Engineering, Inc. confirmed the presence of fill materials in all of the soil borings. The fill contained ash, soil fill materials, brick and leather to approximately 4-ft to 7-ft below grade. This is ' consistent with the reported landfill use of the site. Natural soils found below the fill materials were described as grey-sand and silts which we classified in the "C" ' hydrologic soil group. Groundwater was encountered within the fill layer at 3-ft to 6- ft below grade. Due to the landfill and junkyard uses of the site, high groundwater table, and ' location adjacent to a site (Furlong Park) that is known to contain contaminated soils and has the same landfill history as the subject property, installing an infiltration ' device to meet the MassDEP recharge volume requirement number 3 seems potentially more harmful to the environment than beneficial. According to the 2013 ESA by SP Engineering, Inc., the site has been exposed to hazardous materials ' associated with its historical filling, use as a municipal landfill, and junkyard operations. Furlong Park has soils that were classified as contaminated and required remediation under the MCP program to reduce potential risks to park ' patrons from soils containing metals and PAHs associated with historical urban fill. Installing an infiltration device in on-site fill materials may mobilize pollutants in the fill and may cause or contribute to groundwater contamination. ' The potential loss of annual recharge associated with not meeting Standard number 3 at this site will not have a significant environmental effect: there are no ' downstream wetland areas that would benefit from additional recharge nor is there a need for additional groundwater contributions to this portion of the North River, as might exist in a non-tidal river or at a site that occupied a larger portion of a watershed. The adjacent Furlong Park is documented as containing contaminated soil conditions, so additional groundwater contribution from this site would not be beneficial to that property or its downstream areas. A-3 ill ' At this site, Standard No. 3 is met to the maximum extent practicable. For the reasons described above, and to the benefit of the local environment, recharge devices are not proposed. ' 2.4 Standard 4: Water Quali ty ty The minimum required water quality treatment volume for the project site is the first half inch of runoff from impervious surfaces. The proposed stormwater treatment system is designed to provide a weighted average of approximately 87.2% TSS removal. The reader is referred to Water Quality Volume Calculations provided in tAttachment B. The water quality volume is satisfied by a First Defense (FD) proprietary separator ' pretreatment device. The FD pretreatment device at the site is predicted to achieve an annual 96% TSS removal rate. The FD directs flow to the existing municipal drain pipe that discharges to the North River. The proprietary separator was sized to ' adequately treat the required water quality volume by converting the WQV to an equivalent peak flow rate. Additionally, existing catch basins adjacent to the site in Franklin Street will be cleaned and retrofitted with hoods to improve their ' performance. ' Computations for the proposed proprietary separator are provided in Attachment B. The equivalent Water Quality Flow (WQF) rate calculation was performed in accordance with MassDEP guidelines. The calculated WQF rate was used with the t manufacturer's TSS Removal Efficiency Curve to estimate the annual TSS removal. The efficiency calculations were based on third-party evaluations of the First Defense proprietary separators. The third-party evaluations are provided in ' Attachment F. As required by the Stormwater Management Standards, a Long-Term Pollution ' Prevention Plan has been prepared for the project and is provided in Attachment C. The plan identifies suitable practices for source control and pollution prevention throughout the useful life of the site. ' 2.5 Standard 5: Land Uses with Higher Potential Pollutant Loads In accordance with the Massachusetts Stormwater Management Standards, the ' proposed primary site use is not considered a Land Use with Higher Potential Pollutant Load (LUHPPL). Therefore, this standard does not apply. ' 2.6 Standard 6: Critical Areas The project site is not tributary to an environmentally-critical area as defined by the Massachusetts Stormwater Management Standards. Therefore, this standard does ' not apply to this project. ' A-4 2.7 Standard 7: Redevelopment and Other Projects Subject to the Standards only to the Maximum Extent Practicable The site has been v previously de eloped with aone-story garage and office structure, and the junkyard. Existing surfaces are primarily gravel, dirt, and pavement. The ' 19,560 sq. ft. increase in impervious surfaces at the site is considered new development and the remaining portion (26,480 sq. ft.) of the project site is redevelopment. ' The proposed project will improve existing conditions at the site. The project will remove the industrial use at the site eliminating several sources of pollutants. I ' Approximately 52,900 sq. ft. of junkyard will be replaced with vegetation such as lawn and planting beds. The stormwater management system will capture and treat approximately 16,800 sq. ft. of proposed parking and walkway surfaces prior to discharging to the North River. The proposed buildings will replace approximately ' 25,000 sq. ft. of junkyard and will have clean roof runoff discharging towards the q 1 Y 9 9 North River. In total, approximately 94,700 sq. ft. (96%) of the project site will be improved by eliminating pollutant sources and providing pretreatment to stormwater runoff. Additionally, existing catch basins in Franklin Street adjacent to the site will be cleaned and retrofitted with hoods and the existing 15-inch diameter discharge to the North River will be cleaned and a rip-rap apron will be installed. ' All of the proposed work area meets standards 1, 2, &4 through 10 except for approximately 3,885 sq. ft. of impervious area located adjacent to Franklin Street. This area is considered "de minimus" under the criteria listed in the Massachusetts Stormwater Management Handbook. Prior to site redevelopment, stormwater runoff from approximately 1,970 sq. ft. of existing pavement drains to the Franklin Street municipal drainage system. The project increases the amount of impervious area ' tributary to these Franklin Street municipal catchbasins by approximately 1,915 sq. ft. The existing catch basins in Franklin Street will be improved by cleaning and installing hoods to better provide stormwater treatment; however the improved ' catchbasins will not meet a 80% TSS removal standard. Due to the small size of this area, and its location downstream of the project, the de minimus provision applies. ' 2.8 Standard 8: Construction Period Pollution Prevention and Erosion and Sediment Control Consistent with the NPDES Construction General Permit requirements, a ' Stormwater Pollution Prevention Plan (SWPPP) is required for any project resulting in over 1-acre of land disturbance. The proposed project anticipates approximately ' 2.27-acres of land disturbance. Therefore, a SWPPP will be prepared and submitted to the issuing authority prior to land disturbance commencing. ' A-5 ',I 1 1 2.9 Standard 9: Operation and Maintenance Plan An Operations & Maintenance Plan has been provided in Attachment D. The 1 owners of the land are responsible for the system operation and maintenance. 2.10 Standard 10: Illicit Discharges j 1 The submitted Long-Term Pollution Prevention Plan (Attachment C) specifies measures to prevent illicit discharges from entering the stormwater management system. Source control and response plans are also specified to prevent illicit 1 discharges from being conveyed through the stormwater management system. Since the project site has been previously developed, a signed Illicit Discharge 1 Compliance Statement cannot be provided at this time. A component of the proposed project includes abandoning existing utilities from the industrial buildings and site. Consistent with the Massachusetts Stormwater Handbook, the property owner will submit a signed Illicit Discharge Compliance Statement prior to discharging any stormwater runoff to the post-construction stormwater BMP s. A draft copy of the Illicit Discharge Statement is provided in Attachment E. 1 3.0 SUMMARY ' The proposed drainage system and site redevelopment plans for the residential development at 16, 18 AND 20R Franklin Street conforms to MassDEP Stormwater 1 Management Regulations. The proposed drainage system will treat and remove TSS and other pollutants throughout the project area and minimize erosion. Proper construction and operation and maintenance of the proposed drainage system are 1 critical to its long-term performance. To that end, an Operations and Maintenance Plan and Long-Term Pollution Prevention Plan have been prepared and will be instituted throughout the facility's life. 1 1 A-6 I ATTACHMENT B ' STORMWATER COMPUTATIONS 1 t B.1 - Water Quality Volume Calculations ' B.2 - Water Quality Flow Calculations B.3 - Test Borings August 2013 by SP Engineering ' B.4 - TSS Removal Calculation Worksheets ' B.5 - TSS Removal Efficiency Curve (by Hydro International) 1 1 1 � Griffin Engineering Group, LLC 495 Cabot Street, Suite 2 ' Beverly, MA 01915 Phone:978-927-5111;Fax:978-927-5103 ' WATER QUALITY VOLUME CALCULATION ' Job Name: Tranos-Franklin Street Job No: 1573 Date 8/25/2017 Designer MBP Checked By: RHG REQ. WATER QUALITY VOLUME(WQV) DEPTH = 0.5 inch(s)of runoff ' WEIGHTED AVERAGE TSS REMOVAL CALCULATION ' Total Area Pavement Roof WQV %TSS Imp.Area x Tributary Subcatchments* Treatment Train s s s c Removal TSS P1 Series, P2A, P2B& P2C 34598 16795 10638 1,143 96% 26,336 First Defense ' P4 4,680 2,896 39 122 25% 734 We minimus Areas P5 1,412 955 0 1 40 1 25% 239 De minimus Areas Total: 40,690 20,646 10,677 1 1 87.2% 27,308 "See Subcatchment Plan DR-2 in Attachment D. ' Id Weighted Calculations: Average WQV= Imp.Area x 0.5-inch x 1-foot/12-inches ' Weighted Average%TSS Removal=Total Imp.Area x TSS/Total Imp.Area Notes: 1 1.)Stormwater runoff from the roof(Subcatchments R1, R2A, R3A, R4A, R413,&P3) is omitted from the weighted average calculations unless routed through the Water Quality Structure. MassDEP considers roof runoff to be clean. 2.) Subcatchments P1 &P2 contain no significant impervious surfaces so they were omitted in the weighted average calculation 3.)The WQV for the First Defense Proprietary Separator(WQS#1 &#2)was converted to a WQF per MassDEP requirements. (See Water Quality Flow Calculations) 4.) Refer to Attached TSS Removal Efficiency Curve Prepared by the Manufacturer, Hydro International for the First Defense Proprietary Separator. Removal efficency is calculated based on the WQF. 5.)The proposed impervious areas from Subcatchments P4 is considered"de minimus"under the criteria listed in the Massachusetts Stormwater Management Handbook. i 1 1 Page 1 of 1 B.1 Griffin Engineering Group, LLC 495 Cabot Street, Suite 2 Beverly, MA 01915 ' Phone:978-927-5111;Fax.978-927-5103 WATER QUALITY FLOW CALCULATIONS t Job Name: Tranos- Franklin Street ' Job No: 1573 Date: 8/25/2017 Designer: MBP ' Checked By: RHG PROPRIETARY SEPARATORS ' REQ. WATER QUALITY VOLUME (WQV) DEPTH = 0.5 inch(s)of runoff ' Structure Name Imp. Area A s tc(min.) t,(hrs.) qu Q1.0 Proposed Proposed (sf) (miles ) (csm/in) (cfs) Device Configuration DMH3(FD#1) 27,433 0.00098 6.0 0.10 774 0.381 4' FD Online Notes: Qo.s= (gc)(A)(WQV) where: Qo.5= flow rate associated with first 0.5-inch of runoff(WQF) qu =the unit peak discharge in csm/in A= impervious surface drainage area in square miles WQV=water quality volume in watershed inches (0.5) ' DMH3 (FD#1) -FIRST DEFENSE PROPRIETARY SEPARATOR Internal Bypass Configuration ' Bypass Flowrate= 0.7 cfs (Per Manufacturer) WQF=0.38 cfs-> OK Page 1 of 1 B.2 FRANKLIN N- .�." Former Tannery. �`y�\ ST REE T / Truck Fence Parking OMW-t Gar a Parking / _ ` r fence City of Salem Burnham Marine �YY White � �i Liner Metal ti C0ntr0Ctar5 Truck with / _ X r 0MW-2 waste oiler _ SS=1-, r- — �{ ,,// gas tanks/ -' J (� and antifreezes O (Liner t BalIfield/Playground Foreba ', , Car / /` Stripping Rack 1 y oo�' MW-6 // Starag/ ---� // !: It t Fm / fit°oo,�.` / � \ ! r i TS= TEST BORE j Grassy-,.AY-�' MW=MONITORING Swale Low Spot �! t t. tt d ! WELL /-' ✓� ei r I t SS=SURFACE /<\`10i ,/ t/ �I�� ! % ! r✓ ence SAMPLE ✓X / Trees ( Prop.Line \ SS-2 t I ! F/W/ �� .\\ �\ow3pot M 5 Access RoadC) Q� _ iTrees I��_40� TB=2 _ _ _ —� \ Sep ` ~ 1�W�3 ` ` r� Storm Drain. NORTH XSS T<o� t SITE. PLAN . RIVER %e FERRIS. AUTO SERVICE (Tidal ) <I\ Top o1 Bank 16-20 FRANKLIN ST. SALEM,MA ~FIGURE TWO SP,INC. 9- 10-13 ' DEPTH TB-1 West Burnham LOCATION TB-2 center property (Feet) MW-5 56' from River MW-3 54' from River HNu HNu Coarse gravel, 0 Coar a gravel 0 ' Small rock y Grey stone, glass 0 1 Gravel, red fiber ' 2 Grey stone ash + gravel 0 1 3 orange ash, grey ash ' coal cinders, wet 0 2 Blk/ grey ash, wet 0 4 ' S brick then loose, 0 Blk silt, ash, sand, rock 1 Blk silt oily smell 1 6 7 $ Blk silt + sand 0 Grey ash wood 0 j 9 Green clay y MW-5 ' 10 grey/green uniform sand 5 solid screen MW-3 10' screen Riser 5' solid 11 15 Riser z 15 Soil Logs ' Ferris Auto Services 18 Franklin St. Salem, MA ' DEPTH TB-3 Ballpark NE LOCATION TB-4 waste fluid storage (Feet) MW-4 52' from River MW-6 center west property ' HNu HNu 0 Tan, brown gravel 0 Pave I + stone 0 1 Tan sand + rock, concrete ' 0 2 Blk grit, 0 Grey fine sand 0 Brick and concrete 1 W 3 Blk sand and silt 0 4 Blk silt + filer 0 ' Red bark 1 5 Blk silt, wood, 0 Red bark 0 Ash, cinder 1 6 $ Gravel, Blk stone, wet 0 fine/med sand rocc�k wet U 0 9 MW-4 ' 10 10' screen Fine grey sand 5' solid Riser I MW-6 11 1 10' screen Grey silt + clay Grey clay 5' solid Z12 I 15 y 15 Roadbox W Soil Logs ' Ferris Auto Services- 18 Franklin St. Salem, MA INSTRUCTIONS: Nonautomated.,Mar.4,2008 1. Sheet is nonautomated. Print sheet and complete using hand calculations. Column A and B: See MassDEP Structural BMP Table 2.The calculations must be completed using the Column Headings specified in Chart and Not the Excel Column Headings 3.To complete Chart Column D, multiple Column B value within Row x Column C value within Row 4.To complete Chart Column E value,subtract Column D value within Row from Column C within Row 5.Total TSS Removal=Sum All Values in Column D Locationd Between Bldgs#2 &#5(DMH4) A B C D E TSS Removal Starting TSS Amount Remaining BMP' Rate' Load* Removed B*C Load C-D First Defense Proprietary Separator 96% 1.00 0.96 0.04 > i O O � O U) co cv t� Separate Form Needs to be Completed for Each Total TSS Removal = 96% Outlet or BMP Train Project: Trano.a-9 S.Mason Street: Prepared By: MBP *Equals remaining load from previous BMP (E) Date: August 2017 which enters the BMP Hydro International stormwater 4-ft Diameter First Defense 100"/0 Removal Efficiency Curve* 96% 90% -------- ------- -------- ------ -+-------- -------- ----- -- -------- --------1--------- 1 1 I 1 I I I I , I I I 1 I I ° , I ' 1 I I 1 I I I 1 I I L1 I 1 1 1 1 1 1 I 1 1 1 1 I 1 1 I 1 50% 1 , 1 1 I 1 1 <ti 1 1 1 By ass fl�rate=OJCIS40% _____--_L_____-- L__ L _ __ ___i___-- cz I I 1 I 1 I 1 I 1 I 1 1 1 1 1 1 1 1 30°/O --------' 1 I I I 1 1 1 1 1 1 I I 1 1 1 1 1 1 1 I I 1 I 1 1 1 1 20% -----_-- 'Note: R ults arc based on the M inc ; Der artment of Environmenta I Protection , Tes Jng Protocols-(Available Upon Request) 10% -------- ------- +--------+------ -+-------- II , M--___-_-+___-_ __.�--_-----y______--1____-�-__ 1 1 ( 1 1 1 1 1 I 1 1 1 1 1 1 I 1 1 I 1 I 1 1 1 0% I I I I 1 I I I I 0 0.1 2 0.3 0.4 0.5 0.0 0.7 0.8 0.9 1 I ow rate Ws) Q = 0.19cfs Q = 0.67cfs Hydro International - 94 Hutchins Drive- Portland, ME 04102 Tel: (207) 756-6200 - Fax: (207) 756-6212 www.Hydro-International.biz Q � i 1 1 1 1 1 1 1 1 ATTACHMENT C ' LONG TERM POLLUTION ' PREVENTION PLAN 1 1 1 ' Long Term Pollution Prevention Plan ' Standard #4 of the MA DEP Stormwater Management Handbook requires that a Long Term Pollution Prevention Plan (LTPPP) be prepared and incorporated into the long term ' operation and maintenance plan of the projects stormwater management system. The purpose of the LTPPP is to identify potential sources of pollution that may affect the quality of stormwater discharges and to describe suggested practices to reduce pollutants in stormwater discharges. Good housekeeping practices- The subject property owner is to keep the site in a neat J p p Y p ' and orderly condition so that pollutants are not conveyed to the storm drainage system or the North River. Materials swept, blown or washed into the storm drains or can decrease the system's effectiveness and could eventually be conveyed into the North River. ' Some examples of good housekeeping practices are pavement sweeping, litter control, contained outdoor waste and cigarette disposal receptacles, and protected material storage areas. The property owner should provide proper training and assign ' responsibilities to personnel to keep the site in a neat and orderly condition. Provisions for storing materials and waste products inside or under cover—A trash and ' recycling disposal company(s) hired by the owner will pick up waste materials and properly dispose of them at a state approved disposal facility. The proposed trash and recycling receptacles located within the first floor garage areas will be properly ' maintained and emptied at least once a week. The stormwater drainage system has catchbasins with hooded outlets and deep sumps designed to capture and retain trash, debris, oils, and sediments. Downstream of the catchbasins but before the stormwater outfalls, proprietary separator is also installed to further intercept trash, debris, oils, and sediments that might have entered the stormwater ' drainage system. Vehicle washing controls— Outdoor vehicle washing has the potential of conveying wash ' water with heavy concentrations of detergents and sediments into the stormwater drainage system. The project site does not include any designated vehicle washing areas, nor is it expected that vehicle washing will take place on-site. Requirements for routine inspections and maintenance of stormwaterBMP's- Consistent with Standard 9 of the Massachusetts Stormwater Management Regulations, an, Operation and Maintenance Plan has been provided in the Stormwater Management Report. The plan details routine inspection and maintenance of the stormwater BMP's along with associated record keeping forms. ' Spill prevention and response plans— Sources of potential spill hazards include vehicle 16, 18, & 20R Franklin St. August 2017 LTPPP-1 ' fluids and fuels, pesticides, paints, solvents, and liquid cleaning products. These exterior spill hazards have the potential to enter the stormwater drainage system and are ' to be addressed as follows: 1) Spill hazards of pesticides, paints, and solvents shall be remediated using the ' Manufacturers' recommended spill cleanup protocol. 2) Vehicle fluid and fuel spills shall be remediated according to local and state regulations governing fuel spills. 3) The property owners shall have the following equipment and materials on hand to address a spill clean-up: brooms, dust-pans, mops, rags, gloves, trash bags, trash containers, and absorptive materials such as sand, sawdust, or kitty litter. 4) Spills of toxic or hazardous materials shall be reported to the Massachusetts Department of Environmental Protection at 1-888-304-1133. ' Provisions for maintenance of lawns, garden, and other landscaped areas- It should be a general goal of the subject property owner to achieve a high-quality, well-groomed and stable landscape that evolves throughout the seasons and protects the overall condition ' of the property. All landscaped areas are to be maintained with dense vegetative growth or a layer of mulch so as to minimize sediment transport. Litter and waste is to be t removed weekly from the landscaped areas and adjoining parking lots and disposed of properly. ' Requirements for storage and use of fertilizer, herbicides, and pesticides - Fertilizers, herbicides, and pesticides are not to be stored on site or within the buildings. Should use of some become necessary, application should be performed by a state licensed contractor in accordance with the manufacturer's label instruction and when environmental conditions are conducive to product application ' Pet waste management provisions-All pet waste is to be scooped up, sealed in a plastic bag, and disposed of properly in the garbage. Pet waste should never be deposited in the stormwater management system for it contains high level of fecal coliform bacteria. ' Provisions for operation and management of septic systems— There are no septic systems associated with the project site. The sanitary sewer is proposed to be ' connected to the city sewer main in South Mason Street & Buffum Street Extension. Snow disposal and deicing chemicals— Snow will be stockpiled on site within open space ' areas until the stockpile areas become a hazard to the daily operation of the site. At that point, snow is to be disposed of at an off-site location. It will be the responsibility of the hired snow removal contractor to properly dispose of transported snow according to the ' Massachusetts DEP, Snow Disposal Guidelines. It is the responsibility of the snow removal contractor to follow these guidelines and all applicable laws and regulations. ' 16, 18, & 20R Franklin St. August 2017 ' LTPPP-2 � 1 1 The property owners, or hired building maintenance company, will be responsible for the clearing of the sidewalks and building entrances. The owner may be required to use a de-icing agent such as salt or potassium chloride to maintain a safe walking surface. The de-icing agent for the walkways and building entrances may be kept on site in a ' designated storage room within the building. De-icing agents are not to be stored outside. I� 1 16, 18, & 20R Franklin St. August 2017 LTPPP-3 ATTACHMENT D OPERATION & MAINTENANCE PLAN 1 1 1 1 I � ' OPERATION & MAINTENANCE PLAN iSystem Owner: Juniper Point Investment Co., LLC ' Pa Res on i Party p s ble for O&M: The owner shall be responsible for the construction phase and the long-term operation and maintenance of the stormwater management system as outlined in this Operation and Maintenance (O&M) Plan. Should ownership of the property change, the ' succeeding owner shall assume all responsibilities for implementing this Operation and Maintenance Plan. Emergency Contact Information: • Salem Fire & Police (Emergency) 911 • Salem Fire Department (Business) 1-978-744-6990 ' • Salem Police Department (Business) 1-978-744-0171 • Salem Conservation Commission 1-978-619-5685 • Salem Health Department 1-978-741-1800 ' • Salem Public Works Department 1-978-744-3302 • Salem Engineering Department 1-978-619-5673 • Mass DEP (Emergency Response) 1-888-304-1133 ' • Mass DEP (Northeast Regional Office) 1-978-694-3200 Note: The system inspectors should note that drainage pipes, catchbasin, manholes, ' and treatment devices are considered "confined spaces"subject to strict OSHA standards regarding safe entry. Confined spaces present inherent hazards to workers. Only appropriately trained staff with appropriate safety equipment and monitors may ' enter confined spaces, and then only with a specific entry permit. Also, this work may pose hazards to workers, such as soft ground, flowing or standing water, snakes and rodents. Again, only appropriately trained staff with the necessary safety equipment should undertake such work. ' Phase I: Construction Period Operation and Maintenance Plan ' Following is the general sequence of anticipated construction events: 1) Install proposed erosion controls and construction entrance(s). ' 2) Abandon all existing on-site utilities, demolish existing building, and perform any required clean-up on-site such as removing litter, automobile parts, etc. O&Mplan August 2017 1 3) Clear site and grub areas as they become necessary. ' 4) Perform all remediation activities on-site such as removal of all landfill material from the proposed building footprints. ' 5) Excavate and install the Building #2 foundation. Backfill foundation to bring site to rough grade. Repeat for Buildings #3 through #5. 6) Install all water, sewer, and drainage lines and structures within the parking area. Install conduit for electrical service. Abandon the existing drainage line within Building #1 footprint. (Note: Do not install frame and grates/covers on the sewer drainage structures until the fine grading phase. Provide large metal plates over the precast openings and bury as required.) 7) Excavate and install the Building #1 foundation. Backfill foundation to bring site to rough grade. ' 8) Install building utility services. Gas company to install gas main, services, & meters. ' 9) Bring site to finish grade. Install frame and grates/covers to finish grade. Vacuum all precast drainage structures and install and maintain geotextile filter fabric in all catchbasin grates until final paving. ' 10)Install bituminous pavement binder course. 11)Install curbing, sidewalks, and landscaping. ' 12) Install final pavement, signage and striping. ' Installing and maintaining comprehensive erosion controls during construction is critical to the protection of the environment and the proposed drainage system. Following is a list of erosion control measures to be taken to protect the existing Salem drainage system and the proposed drainage system during construction. 1) Install haybales and silt fence downhill of all proposed work area as shown on ' the Grading and Drainage Plan (Sheet C-5). 2) Install the construction entrance(s) at entrance off of Franklin Street. ' 3) Temporary soil stockpiles shall be encircled with haybales and stabilized with erosion control matting or temporary seeding, depending upon the proposed ' duration. 4) Stabilize all disturbed areas as soon as practicable. Provide temporary ' stabilization of soil to be exposed for a long period of time (i.e. one month). O&Mplan August 2017 2 5) Install erosion control matting on all proposed vegetated slopes greater than ' 3:1 (H:V). 6) All erosion control measures are to be inspected weekly and after each rainfall ' event. Additional erosion control materials (i.e. haybales, silt fence, filter fabric) are to be kept on site and readily accessible as required. ' 7) Sediment accumulation up-gradient of the haybales and silt fence greater than 6" in depth shall be removed and disposed of in accordance with all applicable regulations. ' 8) The stabilized construction entrance(s) shall be inspected weekly. The entrance(s) shall be maintained by adding additional clean, angular stone to ' remove the soil from the construction vehicle tires. If soil is still observed leaving the site from construction vehicle tires, adjacent roadways shall be kept clean by street sweeping. ' 9) Dust shall be controlled using on-site water trucks as required. ' 10) All erosion control measures shall be maintained, repaired or replaced as required or directed by the owner's engineer, the City Engineer, or the City Conservation Agent. ' 11) The contractor shall comply will the Erosion Control Notes listed on the project drawings (Sheet C-1). ' Part II: Long Term Operation and Maintenance Plan The stormwater management system is a series of catch basins located at low points ' within the paved parking lot. Stormwater collected by the catch basins is conveyed through a proprietary stormwater device prior to discharging to the existing municipal drainage pipe that crosses the subject site. ' Stormwater runoff from the building rooftop is collected by gutters and/or scuppers and conveyed by downspouts and roof leaders to the sites drainage system. Roof runoff ' from a portion of Buildings #2, #3 & #4 are discharged overland within areas of lawn. To ensure optimal performance of the stormwater management system, routine ' inspections and maintenance should be done at frequencies specified below. An Operation and Maintenance Plan Schedule form is attached documenting compliance. ' Paved Parking Surfaces—As part of normal site clean-up and as discussed in the Long Term Pollution Prevention Plan, debris is to be removed from the parking lots as it accumulates. Weekly patrolling for litter is recommended. Sand from winter ' ice and traction control should be removed semi-annually (ie. during early spring O&Mplan August 2017 3 1 it ' and late fall). Significant oil leaks should be swept up and disposed of using oil-absorbent materials as they are discovered. Any oil spills or leaks that reach ' the catchbasins must be reported to the Massachusetts DEP oil spill hotline. Catchbasins & Drain Manholes - Remove the grate or cover and visually inspect ' for corrosion and structural damage. Inspect pipe inlets and bottoms for signs of infiltration or inflow. The grate or cover and hoods on the catchbasins should be inspected on a quarterly basis during the first and year and semi-annual thereafter. ' Cleaning of the catchbasins should be done on a yearly basis and by a vacuum truck or clamshell. The contractor is to take care to avoid damaging the ' catchbasin hood. While cleaning, if a layer of oil is observed floating on the water surface, place an oil-absorbent pillow on the surface, allow to soak and remove. Repeat this process until the oil layer is removed. Alternatively, have the oil layer ' pumped out by a licensed disposal contractor and appropriately disposed of. The oil absorbent pillows must be drummed for disposal by a licensed disposal contractor. ' Area Drains— Remove the grate and visually inspect for corrosion and structural damage. The grate and replaceable filter bags should be inspected on a monthly ' basis during the first year and quarterly thereafter. Cleaning the area drain sumps should be done on a yearly basis. The contractor is to take care to avoid damaging the area drain. ' First Defense Stormwater Treatment Device—A copy of the manufacturer's Operation & Maintenance Manual is provided at the end of this section which ' contains the required operation and maintenance procedures for the treatment devices. The devices should be inspected for corrosion and structural damage on a quarterly basis during the first year and semi-annually thereafter. The device ' also should be cleaned on a yearly basis and in accordance with the manufacturer's procedural recommendations. ' Snow Storage Area—The parking lot has been designed with snow storage areas along the edges while maintaining reasonable travel lanes and parking areas. In the event of significant snow accumulation, snow can be placed in the grassed ' area in the southerly portion of the site. Debris from melted snow shall be cleared form the site and properly disposed of at the end of the snow season or no later than May 15tn. O&Mplan August 2017 ' 4 v H dro Awswoft.- y International 1 1 z yy 9 f6 r, E N { Operation and Maintenance Manual First° Defense Stormwater Solutions Vortex Separator for Stormwater Treatment Turning Water Around ...8 ' 2 Page s I First DefenseO Operation and Maintenance Manual Table of Contents ' 3 First Defense®by Hydro International -Benefits of the First Defense® ' -Applications -First Defense®Components ' 4 Operation -Introduction ' -Pollutant Capture and Retention -Wet Sump -Blockage Protection 4 Maintenance -Overview -Determining Your Maintenance Schedule ' 5 Maintenance Procedures -Inspection -Floatables and Sediment Cleanout 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 pic 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 plc'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 First DefenseO bvy Hydro International ' Capturing more than 25 years of separation design Benefits of the First Defense® experience,the First Defense®is Hydro International's latest • Compact and flexible design addition to its family of hydrodynamic vortex separators -Can be used as a catch basin inlet and directional intended for stormwater applications. It has been developed change manhole with ease of installation and maintenance at the forefront -Optional one or two inlets without sacrificing performance or design flexibility. - Does not require a bypass structure ' •Hydrodynamic Vortex Separation All internal components are housed in either a Oft or 6-ft -Extended and structured flow path ' diameter precast manhole that is designed to withstand traffic -Minimal headloss -Reduces turbulence and re-suspension loads. Each model can be used as a catch basin inlet or -Reverse-flow outlet intake prevents short-circuiting standard manhole with solid cover so that runoff can enter -Improved efficiency for all flows ' from an overhead grate, inlet pipe or both without diminishing • Delivered Pre-assembled for easy and fast installation performance. • Simple to inspect and maintain • Independently verified ' The First Defense®has internal components that are designed to generate rotational flow within the device Applications without requiring a tangential inlet. Flow within the precast - New developments and retrofits chamber is controlled to prevent turbulence and its unique • Utility yards reverse-flow outlet intake ensures a longer retention time - Streets and roadways by preventing short-circuiting. An internal bypass prevents • Parking lots ' high flow re-suspension and washout and eliminates the - Pre-treatment for filters, infiltration and storage need for additional bypass structures. The internals can - Industrial and commercial facilities easily be adjusted to change the angle between the inlet • Wetlands protection ' and outlet for storm drain directional changes and dual inlets can be accomodated in most cases. This simplifies grading and site design so that flow can be conveyed from isolated locations within the same site without increasing the number of structures. ' For removal of fine sediment and associated pollutants, y< , oil spills, trash and debris,the first choice in stormwaterla treatment systems is the First Defense®. ' .., . First Defense®Components u ry 1. Built-In Bypass �F ' 2. Inlet Pipe 3. Inlet Chute u 4. Floatables Draw-off Port(not pictured) i 5. Outlet Pipe ' 6. Floatables Storage 7, Outlet Chute ' 8. Sediment Storage ' Page 4 s I First DefenseO Operation and Maintenance Manual s r f ' w Operation Maintenance ' Introduction Overview The First Defense®operates on simple fluid hydraulics. It is self- The First Defense®protects the environment by removing a wide ' activating, has no moving parts,no external power requirement range of pollutants from stormwater runoff. Periodic removal of and is fabricated with durable non-corrosive components. these captured pollutants is essential to the continuous, long- No manual procedures are required to operate the unit and term functioning of the First Defense®. The First Defense®will maintenance is limited to monitoring accumulations of stored capture and retain sediment and oil until the sediment and oil pollutants and periodic clean-outs. The First Defense®has storage volumes are full to capacity. When sediment and oil been designed to allow for easy and safe access for inspection, storage capacities are reached,the First Defense®will no longer ' monitoring and clean-out procedures. Neither entry into the be able to store removed sediment and oil. Maximum pollutant unit nor removal of the internal components is necessary for storage capacities are provided in Table 1. maintenance, thus safety concerns related to confined-space- entry are avoided. ' Pollutant Capture and Retention "NEW. 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 are stored on the water surface in the inner volume. The pollutant ..F , storage volumes are isolated from the built-in bypass chamber to prevent washout during high-flow internally-bypassed storm «wMW events. Accessories such as oil absorbant pads are available for Max Oil Oil' Storage Depth 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 is minimized. Wet Sump The sump of the First Defense®retains a standing water level between storm events. The water in the sump prevents stored Sediment sediment from solidifying in the base of the unit. The clean- Storage Storage out procedure becomes more difficult and labor intensive if the ' system allows fine sediment to dry-out and consolidate. Dried sediment must be manually removed by maintenance crews. This is a labor intensive operation in a hazardous environment. ' Fig.1 Pollutant storage volumes in the First Defense®. Hydro International (Stormwater), 94 Hutchins Drive, Portland ME 04102 ' Tel: (207) 756-6200 Fax: (207) 756-6212 Web:www.hydro-int.com ' 5 Page g I First DefenseO Operation and Maintenance Manual ' The First Defense®allows for easy and safe inspection,monitoring Inspection and clean-out procedures. A commercially or municipally owned Inspection is a simple process that does not involve entry into the ' sump-vac is used to remove captured sediment and floatables. First Defense®. Maintenance crews should be familiar with the Access ports are located in the top of the manhole. First Defense®and its components prior to inspection. Maintenance events may include Inspection, Oil & Floatables ' Removal, and Sediment Removal. Maintenance events do not Scheduling require entry into the First Defense®, nor do they require the • It is important to inspect your First Defense®every six months internal components of the First Defense®to be removed. In the during the first year of operation to determine your site-specific ' case of inspection and floatables removal, a vactor truck is not rate of pollutant accumulation. required. However, a vactor truck is required if the maintenance event is to include oil removal and/or sediment removal. • Typically, inspection may be conducted during any season ' of the year. Determining Your Maintenance Schedule The frequency of ceanout is determined in the field after Recommended Equipment installation. During the first year of operation, the unit should be • Safety Equipment and Personal Protective Equipment inspected every six months to determine the rate of sediment and (traffic cones,work gloves, etc.) floatables accumulation. A simple probe such as a Sludge Judge® ' can be used to determine the level of accumulated solids stored in • Crow bar or other tool to remove grate or lid the sump. This information can be recorded in the maintenance log(see page 9)to establish a routine maintenance schedule. • Pole with skimmer or net ' The vactor procedure, including both sediment and oil/flotables • Sediment probe(such as a Sludge Judge®) removal, for a 6-ft First Defense® typically takes less than 30 ' minutes and removes a combined water/oil volume of about 800 • Trash bag for removed floatables gallons. • First Defense®Maintenance Log ' Table 1. First Defense®Pollutant Storage Capacities and Maximum Cleanout Depths ' !- !. !. 4 180 <23.5 202 26 202-342 6 420 <23.5 626 36 626 1,046 ' NOTE The total volume removed will depend on the oil accumulation level. Oil accumulation is typically much less than sediment, however removal of oil and sediment during the same service is recommended. 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. rF j 2. Remove the grate or lid to the manhole. I 3. Without entering the vessel, look down into the chamber to ' inspect the inside. Make note of any irregularities. Fig.2 shows the standing water level that should be observed. 4. Without entering the vessel, use the pole with the skimmer net oP ' to remove floatables and loose debris from the outer annulus of the chamber. 5. Using a sediment probe such as a Sludge Judge®, measure CAUTIONI AVOID INLET CHUTE the depth of sediment that has collected in the sum of the P P � vessel. 6. On the Maintenance Log(see page 9), record the date, unit I ' location, estimated volume of floatables and gross debris j removed, and the depth of sediment measured. Also note ` any apparent irregularities such as damaged components or v , blockages. 7. Securely replace the grate or lid. 8. Take down safety equipment. 9. Notify Hydro International of any irregularities noted during .._..............___..........................................___.._..................._................_....._._.._.............._..........____.._...._........_.._._..._...._......._.._. ' inspection. Fig.2 Floatables are removed with a vactor hose. ' Floatables and Sediment Cleanout Floatables cleanout is typically done in conjunction with sediment Recommended Equipment removal. A commercially or municipally owned sump-vac is used . Safety Equipment(traffic cones, etc) ' to remove captured sediment and floatables(Fig.2). • 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 cleanout are typically conducted once a year during any season. • First Defense®Maintenance Log • Floatables and sump cleanout 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 j pedestrian and road traffic that work is being done. n... ..� 2. Remove the grate or lid to the manhole. 3. Without entering the vessel,look down into the chamber to g inspect the inside. Make note of any irregularities. I �a 4. Remove oil and floatables stored on the surface of the water ' with the vactor hose(Fig.2)or with the skimmer or net(not pictured). j ' 5. Using a sediment probe such as a Sludge Judge®, measure CAUTION! ' the depth of sediment that has collected in the sump of the AVOID INLET CHUTE 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.3). 7. Retract the vactor hose from the vessel. k`; ' 8. On the Maintenance Log provided by Hydro International, , record the date, unit location,estimated volume of floatables r ' 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.3 Sediment is removed with a vactor hose 9. Securely replace the grate or lid. Maintenance at a Glance ' Activity equency 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 cleanouts it is not necessary to remove the entire volume of liquid in the vessel. Only removing the first few inches of oils/floatables and the sediment storage volume is required. H d y ro 4119T!,ow, International First Defense® Installation Log ' HYDRO INTERNATIONAL REFERENCE NUMBER: ' SITE NAME: ' SITE LOCATION: ' OWNER: ONTR T C AC OR. 1 CONTACT NAME: CONTACT NAME: COMPANY NAME: COMPANY NAME: ADDRESS: ADDRESS: ' TELEPHONE: TELEPHONE: FAX: FAX: ' INSTALLATION DATE: MODEL SIZE (CIRCLE ONE): 4-FT 6-FT ' INLET (CIRCLE ALL THAT APPLY): GRATE 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 dro International First Defense® Inspection and Maintenance Log 9 ' Date Initials Depth of Sediment Volume of Site Activity and Floatables Depth Sediment Comments ' and Oils Measured Removed 1 t 1 Hydro International (Stormwater), 94 Hutchins Drive, Portland ME 04102 Tel: (207)756-6200 Fax: (207)756-6212 Web:www.hydro-int.com 1 1 1 Hydro International (Stormwater), 94 Hutchins Drive, Portland ME 04102 ' Tel: (207) 756-6200 Fax: (207) 756-6212 Web:www.hydro-int.com d 1 1 1 1 1 1 1 1 1 1 1 1 1 1 � �a Hydro International CR 1 What is HX? ' HX is Hydro Experience, it is the essence of Hydro. It's interwoven into every strand of Hydro's story,from our products ' to our people,our engineering pedigree to our approach to business and problem-solving. ' HX is a stamp of quality and a mark of our commitment to optimum process performance.A Hydro solution is tried, tested and proven. ' There is no equivalent to Hydro HX. 18 Stormwater Solutions - - - 94 H utchins Drive _._sue-_s., '� !✓ _� , g'sr'__y''x�. n - _�y�� 4r Portland, ME 04102 � ';_ E»= Tel: (207)756-6200 _ 3� Fax: (207)756-6212 stormwaterinquiry@hydro-int.com www.hydro-int.com Turning Water Around...® FD O+M B120S OPERATION & MAINTENANCE PLAN SCHEDULE Project: Tranos- Franklin Street Project Address: 16, 18, &20R Franklin Street Date: 8/25/2017 Party Responsible: Juniper Point Investment Co., LLC Annual Maint. Budget: $5,200 Task Description/Schedule Maintenance Est. Annual Inspection Activity Maint. Cost Date: Inspector: Perform sweeping of paved parking areas and walkways Sweep, power Street Sweeping after spring thaw to remove any traction sand applied broom, or vacuum $2,000 during the winter months. Also, perform sweeping during paved parking lots late fall to remove any leaf litter and debris. and walkways Inspect grates, covers and hoods quarterly for the first Catchbasins& Drain Vacuum Deep Manholes year and semi-annual thereafter. Also, inspect pipe inlets Sump Annually $1,250 and precast structures for infiltration and inflow. First Defense Water Inspect covers, inlets, and plastic insert quarterly for the Vacuum Deep Quality Treatment first year and semi-annual thereafter. Clean yearly per Sump Annually $350 Devices Manufacturers' recommendations n Inspect grates and replace able filter bags are to be None unless Insp. Area Drains inspected monthly during the first year and quarterly Warrants $600 thereafter. Also, inspect pipe inlets and structures for Otherwise infiltration and inflow. Debris from melted snow shall be cleaned form the site Snow Storage Area(s) and properly disposed of at the end of the snow season Clean Annually $1,000 (by May 15th). ATTACHMENT E ' ILLICIT DISCHARGE STATEMENT 1 1 ILLICIT DISCHARGE COMPLIANCE STATEMENT ' I verify that no illicit discharges exist on the 16, 18, & 20R Franklin Street properties. Through the implementation of Long Term Pollution Prevention Plan and Operation and ' Maintenance Plan, measures are set forth to prevent illicit discharges from entering the stormwater management drainage system. Signature Print Name Date Title Company Signature Print Name Date Title Company Note: This certification must be signed before stormwater is conveyed to the proposed stormwater drainage system in accordance with Standard 10 of the Massachusetts Stormwater Management Standards. ' ATTACHMENT ' PROPRIETARY SEPARATOR THIRD-PARTY EVALUATION FOR FIRST DEFENSE 1 1 1 1 1 1 Hyd ro International stormwater S t o r m w a t e r 01; www . hydro - internationaI biz 1 1 First DefenseO Performance Evaluation 1 1 For submission to the Massachusetts Stormwater Technology Evaluation Project (MASTEP) 1 Stormwater Technology Clearinghouse 1 February, 2011 1 1 1 1 Hydro In 1 stormwater 1 First Defense® Performance Evaluation Summary 1 Hydro International successfully completed First Defense® laboratory testing to assess washout retention and SSC/TSS removal efficiency. Test procedures were based on NJDEP and WI DNR protocols. Performance evaluation included varying flow rates up to 200% of the 1 Maximum Treatment Flow Rate (MTFR) and varying influent concentrations using OK-110 silica sand, with 50% pre-loaded sediment sump. 1 Positive removals were achieved for all flows and concentrations, with greater than 70% SSC/TSS efficiency based on the NJDEP weighted removal efficiency calculation method. Non- detectable (<4 mg/L) SSC and TSS effluent concentrations and over 90% sediment retention ' indicated that no detectable washout had occurred. These findings indicate that washout would be minimal even with a larger MTFR or a shallower 1 sump design. Alternatively, it is reasonable to expect that finer particle sizes with lower settling velocities would be retained and not washed out at the tested flow rates. 1 1 1 BYPASS — OUTLET INLET 1 N9^f ? r 9 ) FLOATABI ES STORAGE INLET ' CHUTE OUTLET CHUTE 1 P'LOATABLES '1¢ ` DRAW-OFF-PORT �'}P y �,s SEDIMENT STORAGE Figure 1: First Defense®- Internal components and flow path ' ©2011 Hydro International Performance Evaluation — First Defense® f tnte�afivnal ' stormwater ' Introduction The First Defense® is an enhanced vortex separator designed to remove floating and settleable pollutants commonly found in stormwater runoff. A key feature of the First Defense is an 1 internal Bypass Chute (Figure 1) that allows treatment without requiring additional flow-diversion structures and prevents scour velocities from re-suspending captured pollutants. The MTFRs ' are 0.7 cfs and 2.2 cfs for the 4-ft and 6-ft diameter models, respectively. Internal weirs are set to ensure all flows up to the MTFRs can be treated without bypass. This laboratory-based test program was conducted to evaluate the overall system performance while accounting for variable inlet concentrations and sediment retention over a wide range of loading rates. Test Objectives ' The First Defense was tested utilizing protocols that met or exceeded the most recent recommendations by testing authorities, including NJDEP and WIDNR. Objectives included: ' • Determine the MTFR using washout as the limiting factor. • Quantify washout at 125% and 200% of the MTFR by measuring the maximum effluent concentration and maximum allowable reduction in sump load. • Determine the Suspended Sediment Concentration (SSC) and Total Suspended Solids (TSS) removal efficiency for inlet concentrations of 50 mg/L, 100 mg/L, and 200 mg/L at ' 25%, 50%, 75%, 100%, and 125% of the MTFR, with the sump filled to 50% of the maximum storage volume. • Determine the weighted removal efficiency based on the calculation method described in the NJDEP protocol for laboratory testing of hydrodynamic sedimentation devices. • Provide independent witnessing during testing to validate and confirm procedures ' described and followed in this report. • Validate TSS and SSC analytics by outsourcing samples to an independent, state- certified laboratory. In an effort to satisfy regulations that require results reported according to TSS procedures, ' results of this study included both TSS and SSC analysis. Recent settleable solids performance evaluations are reporting percent removal of SSC with a general consensus that SSC methods can improve the accuracy and repeatability of measurements for samples that have relatively ' high sediment settling velocities. ©2011 Hydro International Performance Evaluation — First Defense® y Page 2 of 8 Hydra ' International stormwater ' Test System Description The distribution of the test material, US Silica OK-110, is shown in Figure 2. Approximately ' 20% of the particles are less than 75 pm with the remaining 80% are between 75 and 150 pm. 100 1 0 80 c M ' 60 L 80% 75-150 microns ' 40 c a� v L a 20 20% <75 microns 0 ' 0 50 100 150 200 250 Particle Size µm ................................. ................................................. .......................... .............I................... ............_ . .............. Figure 2: Test sand particle size gradation (OK-110) ' A full-scale First Defense with 4-ft diameter vortex chamber was tested at Hydro International's state-of-the-art hydraulics laboratory in Portland, ME. Clean water from a 23,000-gallon reservoir was pumped using an 8-inch variable Flygt pump at targeted flow rates through a pipe ' network to the First Defense (see Figure 3). Dosing equipment delivered a slurry of the OK-110 test material to the First Defense. Grab samples were collected at the inlet sampling point and effluent pipe. Effluent was discharged back into the reservoir. ' © 2011 Hydro International Performance Evaluation— First Defense® Page 3 of 8 H Y International stormw ater iSediment Probe ' Slurry Mix Bypass Chute ,�—Effluent Sample Point Outlet Chute Influent Sample Point ' s Inlet Chute 3"Sediment ' False Bottom 10"Support f Figure 3: Cutaway diagram of test setup with false bottom, sediment probe and internal components Washout Test Procedure ' The sediment storage sump was pre-loaded to 50% maximum storage volume by depositing greater than three inches of OK-1 10 on a false floor 10 inches from the sump bottom (Figure 3). ' The sediment depth was measured with a sediment probe at thirteen locations, evenly spaced over the sump bottom, and averaged to determine initial sediment depth. Clean water from the reservoir was pumped to the First Defense vortex chamber at the target flow rate of 0.88 cfs for 125% of the MTFR. After the flow had stabilized, water was pumped to the test unit for a period of 15-minutes. At the conclusion of the test period, the sediment depth ' was re-measured and compared to the initial depth. After determining that greater than 90% of the pre-loaded volume remained in the sump, ' washout testing using effluent sampling was initiated. The pump was restarted at the target flow rate of 0.88 cfs, and influent and effluent samples were collected after the flow rate had stabilized. For a test period of 25 minutes, influent and effluent samples were collected at five- minute intervals, resulting in six paired samples, which were analyzed for SSC by ASTM D3977 Method B and TSS by APHA SM2540D. The test was repeated for the flow rate of 1.4 cfs or 200% of the MTFR. A representative from the University of New Hampshire Stormwater Center observed all of the tests as an independent witness and reviewed data analysis and quality control procedures of the external laboratory used for sample analysis. ©2011 Hydro International Performance Evaluation — First Defense® Page 4 of m8 H E r( International s t o r m w a t e r ' Removal Efficiency Test Procedure The sediment storage sump was pre-loaded to 50% maximum storage volume by depositing ' greater than three inches of the test sand on a false floor 10 inches from the sump bottom. Clean water from the reservoir was pumped to the First Defense vortex chamber. The five target flow rates were 25%, 50%, 75%, 100%, and 125% of the MTFR. Background influent and effluent samples were collected to ensure clean water supplied from the reservoir did not exceed non-detect concentrations of 4 mg/L for SSC/TSS. A slurry mixture dosing system (see Figure 4) was used to obtain the variable influent ' concentrations of 50 mg/L, 100 mg/L and 200 mg/L for the target flow rates. The required mass of test sand was mixed with clean water in a 60-gallon barrel to form the slurry, which was continually stirred to keep the mixture in suspension. The slurry was pumped at a constant rate ' from the mixing barrel to a dosing port located upstream of the First Defense using a peristaltic pump. The first influent sample was collected after displacing three test volumes, or three residence times within the vessel. Four additional influent samples were collected at one- minute intervals. ./ Slurry Mixer ' 60 Gallon Mixing Barrel Peristaltic Pump ti Figure 4: Slurry Mixture Dosing System The first effluent sample was collected one residence time after collection of the first influent sample. Four additional effluent samples were collected at the same time interval, for a total of five repeats. The test was repeated for three influent concentrations at five flow rates, for a total of 150 influent and effluent samples collected for 15 test runs. Dosing was ceased after collection of the last effluent sample. Another set of influent and effluent background samples was collected one residence time after the peristaltic pump had stopped and sediment was no longer entering the system. The influent and effluent samples ' were analyzed for SSC by ASTM D3977 Method B and TSS by APHA SM2540D. ' © 2011 Hydro International Performance Evaluation — First Defense® Page 5 of 8 HW d ro International ' stormwoter ' A representative from the University of New Hampshire Stormwater Center observed 20% of the tests as an independent witness.and reviewed data analysis and quality control procedures of the external laboratory used for sample analysis. Twenty percent of the SSC samples for the ' removal efficiency testing were analyzed by an external laboratory and all TSS samples were analyzed by an external laboratory. Washout Test Results and Discussion The ability of the First Defense to retain sediment solids was evaluated in two ways: ' 1. Measure the reduction in the sediment sump level prior to and following testing at operating rates of 125% and 200% of the MTFR with the sump 50% pre-loaded, and ' 2. Measure the effluent concentrations with the sump 50% pre-loaded with sediment at operating rates 125% and 200% of the MTFR. The goal of the first part of the washout testing was to demonstrate that less than 10% of the ' sediment was reduced (i.e. show greater than 90% of the sediment was retained). Sediment depths were determined by averaging the depth measurements taken from 13 sampling locations within the sump. Sampling locations were replicated for each flow rate with the intent ' of monitoring changes in depths throughout the sump. Although the initial sediment depth was approximately three inches as measured from the false floor, additional sediment was deposited throughout the test program resulting in sediment depths greater than three inches. However, ' for both flow rate tests, the difference in average sediment depth prior to and following testing remained the same and all measurements were greater than three inches. The goal of the second part of the test was to demonstrate that effluent concentrations did not exceed 10 mg/L at operating rates of 125% and 200% of the MTFR. As seen in Table 1, at 50% of the sediment capacity, the effluent concentrations were below the analytical detention limit of 4 mg/L for both TSS and SSC for flow rates of 125% and 200% of the MTFR. Table 1: Washout I test results for First Defenseo at 125% and 200% MTFR iPercent of Influent Flow Effluent EMC m /L MTFR cfs SSC TSS ' 125 0.88 Non detect Non detect 200 1.4 Non detect Non detect Overall, the First Defense met or exceeded the test requirements to show no measurable effluent TSS or SSC concentrations, as well as retaining greater than 90% of the pre-loaded sediment, at both 125% and 200% of the MTFR. ' ©N2011 Hydro International Performance Evaluation— First Defense® Page 6 of 8 H Iff `d r` "� International 4910--7 ' stormwater ' Removal Efficiency Test Results and Discussion Removal efficiency data was based on a total of 150 influent and effluent samples collected ' from 15 test runs at five target flow rates and three target inlet concentrations. Each test run included five influent and effluent samples that were averaged to determine the test run "event mean concentrations" (EMC) and resulting removal efficiencies for SSC and TSS. All tests ' were run with sediment pre-loaded to 50% of the sump volume. ' D- OK-1 10 % Removal Percent Target Target EMC m /L Efficienc ' Test of Flow EMC Influent Effluent Run MTFR cfs m /L SSC TSS SSC TSS SSC TSS 1 25 0.18 50 43 20 2.7 0 94 100 ' 2 25 0.18 100 103 49 6.2 0 94 100 3 25 0.18 200 216 114 7.8 10 96 91 ' 4 50 0.35 50 55 33 11 6 80 82 5 50 0.35 100 107 52 28 14 74 73 6 50 0.35 200 232 98 50 29 78 70 ' 7 75 0.53 50 47 25 23 11 52 56 8 75 0.53 100 105 57 37 26 65 54 9 75 0.53 200 192 126 81 41 58 67 ' 10 100 0.71 50 62 37 28 15 55 59 11 100 0.71 100 123 67 58 33 53 51 ' 12 100 0.71 200 196 ill 107 54 45 51 13 125 0.88 50 39 16 21 13 44 19 14 125 0.88 100 112 50 66 36 41 28 ' 15 125 0.88 200 190 1 104 99 58 48 44 Note: All TSS samples analyzed by external state-certified laboratory. The results from all SSC and TSS test runs with the sump volume greater than 50% full are shown in Table 2. Target flow rates ranged from 25% of the MTFR (0.18 cfs) to 125% of the ' MTFR (0.88 cfs) and target influent EMC concentrations ranged from 50 mg/L to 200 mg/L. Consistent with flow-based separation systems, the results indicate that system performance was dependent on flow rate, with higher removal efficiencies achieved at lower flow rates. In general, the discrete removal efficiencies for the 15 test runs remained positive for flow rates up ' to 125% of the MTFR, at which point bypass would be occurring. This demonstrates better control over the tested loading rates than conventional gravity-based separators with internal bypass. © 2011 Hydro International Performance Evaluation — First Defense® Page 7 of 8 r Nydr+ International tstorrnwater ' All samples were included in calculating the removal rates, as there were no observed outliers. Minimal variation was measured between the SSC target influent concentration and the measured SSC concentrations. Measured influent TSS concentrations were approximately ' 50% lower than the target EMC. However, lower TSS measurements are expected for particles having high settling velocities due to the TSS analytical method, and both the TSS influent and effluent measurements were consistent with this trend. As a result, the variation of TSS influent ' concentration relative to the target EMC did not have a significant effect on removal efficiencies. The annual system performance was calculated using the NJDEP method for weighting removal ' efficiency data. The results in Table 3 show that the First Defense will achieve approximately 70% removal of SSC/TSS based on the NJDEP weighted removal efficiency calculation. ' . . Defense ' Target NJDEP Average Removal Weighted Removal Flow Weight Efficiency Efficient % MTFR cfs Factor SSC TSS SSC TSS ' 25 0.18 0.25 95% 94% 24% 23% 50 0.35 0.30 77% 79% 23% 24% 75 0.53 0.20 58% 63% 12% 13% ' 100 0.71 0.15 51% 47% 8% 7% 125 0.88 0.10 44% 32% 4% 3% ' Treatment Efficient = 71% 70% Washout Testing Conclusions ' The washout test results showed no measurable washout from the First Defense when 50% of the sump was pre-loaded with OK-110 at flow rates of 125% and 200% of the MTFR. ' Additionally, washout test results showed sediment retention greater than 90% of the pre-loaded sediment for both 125% and 200% of the MTFR. ' Washout testing results also met the NJDEP protocol requirement of less than 10 mg/L effluent concentration for both 125% and 200% of the MTFR. In conclusion, the First Defense met or exceeded the test requirements to show no measurable effluent TSS or SSC levels. This ' implies that a larger MTFR or a shallower sump is possible. Alternatively, it is reasonable to expect that finer particle sizes with lower settling velocities are likely to be retained and not washed out at the tested flow rates. ' Removal Efficiency Testing Conclusions Removal efficiency results from 15 test runs, operating within a flow range of 0.18 — 0.88 cfs showed good correlation between flow rate and removal efficiency for both SSC and TSS. In general, removal efficiencies were independent of the inlet concentrations, which ranged from 50 to 200 mg/L. The NJDEP weighted TSS/SSC removal efficiency calculation showed that ' overall performance was 70% for the First Defense with sediment pre-loaded in the sump to reduce the sump volume by 50%. t ©2011 Hydro International Performance Evaluation — First Defense® Page 8~of 8 �MGriffin Engineering Group,LLC May 21, 2018 Ms. Amanda Chiancola, Staff Planner Salem Planning & Community Development 120 Washington Street, Td Floor Salem, MA 01970 Subject: Juniper Point Investment Co, LL MAY 2 3 2018 r Site Plan Review Application � 4§ "t Ha and Overlay District Special Permit-North R er&NabWnium 16, 18 & 20R Franklin Street Dear Ms. Chiancola: I This letter responds to the October 16t" comments from Mr. William Ross, P.E., of the New England Civil Engineering Corp(NECE) regarding the subject application. Updated project plans have been submitted on April 26t" incorporating our responses as described below. A copy of the NECE comment letter is also enclosed; we have condensed their comments below (the italicized text)to assist the reader. 1) Submittal Package. Response: No response required. 2) Flood Hazard Overlay District Special Permit. 1. Proposed use will comply to the uses and provisions of the underlying district. Response: Multi-family residential use associated with newly constructed buildings is permitted in the North River Canal Corridor NRCC i( ) district provided that each unit located within 100-feet of a residentiallyused parcel has a p separate exterior first floor entrance. The proposed project satisfies this requirement. Zoning relief is required for the project as proposed. Such relief will be applied for as the Planning Board permit process concludes. 2. Adequate convenience and safety of vehicles and pedestrian movement within the site and adjacent street or properties in the event of flooding. Response; The entire site and the public way adjacent to the site are in a FEMA mapped flood hazard area (Zone AE; base flood elevation Phone 978-927-5111 Fax 978-927-5103 1 www.griffineng.com �- 49S Cabot_Street 2nd Floor Beverly;N1A 01915 Ms. Amanda Chiancola Re: Juniper Point Investment Co., LLC Page 2 May 21, 2016 10'). Existing site elevations vary from approximately 7 to 9 feet. The Franklin Street roadway elevation at the site ranges from elevation 8.6' to 7.6'. Proposed grades within the site have been modified to provide safe pedestrian movement above elevation 10.0' from each dwelling unit to Franklin Street. All proposed building garage slab elevations are at or above elevation 11.0'. The lowest CB rims within the site are elevation 9.0 feet, except along Franklin Street. This creates vehicle pathway above elevation 9.0' (i.e., 12-inch maximum floodwater depth in the 100-yeas storm event). The attached Figure 1 shows the portion of the post-development site that is located above flood waters. The duration of flooding at this site is expected to be short due to tidal influence. 3. Utilities shall be located and constructed so as to protect against flooding. Permit narrative refers to development plans and narrative that utilities are above flood elevation Response: The ground elevation at the proposed transformer is approximately 11.4' which is above the base flood elevation. Spot elevations on plans clarify proposed grades. The ground elevations where the gas meters will be installed are above elevation 10.0'. HVAC equipment will be installed on the roofs of the proposed buildings per Architect. 3) Proposed Conditions— Grading-provide more grading details; identify area below base flood elevation. Response: Top and bottom of curb elevations and spot grades at building entrances/exists have been provided on Sheet C-5. Figure 1 delineates the portions of the site above the base flood elevation in post-development conditions and shows walks, parking spaces, building. entrances, and contours: 4) Provide a Demolition Plan, Response: Demolition Plan attached (Sheet C-10). Ms. Amanda Chiancola Re: Juniper Point Investment Co., LLC Page 3 May 21, 2016 5) Contamination— Monitoring Well; provide additional information on any related contamination/mitigation on the site and impacts on proposed groundwater infiltration. Response: Collected runoff will not be directed towards infiltration structures due to the landfill and junkyard uses of the site, high groundwater table, and location adjacent to a site (Furlong Park) that is known to contain contaminated soils and has the same landfill history as the subject property. Installing an infiltration device seems potentially more harmful to the environment than beneficial. Refer to the 2013 Environmental Site Assessment Report by SP Engineering, Inc. 6) Sanitary Sewer- Provide projected post-development sanitary flows for the development and evaluate downstream sewer manholes for evidence of surcharge or accumulated debris that may result in capacity concern. Response: No surcharge or significant debris accumulation was found in the existing sewer manholes located in front of the site and downstream of the project. These sewer manholes were inspected on May 1, 2018. The proposed residential development (123 bedrooms) sanitary design flow is approximately 13,530 gallons/day (9.4 gallons per minute) per Title 5. The daily peak flow rate (hourly maximum) is estimated to be 40 gallons per minute. 7) Garage Drainage— Provide additional detail on oil/water traps and garage drains. Response: The locations of the vents for the proposed MDC traps have been added to Sheet C-4 The vents will be underground into the building and then extend to the roof. Drainage within the multi-car garages will consist of floor drains with 6-inch diameter C.I. pipe capturing and directing any runoff to the MDC traps. 8) Existing Drain— Confirm the size of the drain pipe on the property in buried manhole and/or at outfall, and consider adding a tide gate to outlet to improve performance for tidally influenced drain line. Response: Griffin Engineering verified that the existing drain line upstream of EDMH2 is an 18-inch VC pipe. The existing drain pipes from EDMH2 to the outfall are 15-inch VC pipe. Ms. Amanda Chiancola Re: Juniper Point Investment Co., LLC Page 4 May 21, 2016 The proposed connection to the existing 15-inch VC pipe that is located on the project site has been eliminated. A separate outfall is proposed for the on-site drainage system (Refer to Grading and Drainage Plan last revised 5/21/18). The project proposes to clean and clear the existing 15-inch VC discharge and install a rip-rap apron to reduce erosion. A tide gate on this municipal drain line is not proposed. 9) Proposed Drainage— Recommend Applicant complete exploratory excavation to determine the reason for the existing siphon and if proposed. drain can be installed as designed. Applicant to provide a drain easement. Response: We believe the reason for the existing siphon is to avoid the existing 12-inch diameter water main. The proposed connection to the existing drain manhole EDMH2 has been eliminated from the project. A 40-foot wide drainage easement is proposed and shown on sheets C-3 (Site Layout) and C-5 (Grading and Drainage Plan). 10)Proposed Roof and Area Drains— Revise the Stormwater narrative in EIS to reflect the plans and confirm that the new proposed outfalls will not change the stormwater management plan and narrative. Applicant to clarify whether and where roof drainage is proposed to be infiltrated and revise plans and narrative to be in agreement. Response: The Stormwater narrative in the EIS has been. Please find attached page 12 of the EIS and the revised Stormwater Management Report. Proposed roof drains for Building C will discharge directly to the North River via an 8-inch PVC pipe (Outfalis #1). Roof drainage from Buildings A, B, D, and E will discharge to the proposed on-site drainage system. 11)Water— Request Applicant to provide additional.information regarding proposed peak domestic water use, clarification on required fire flows for each building and complex, and condition and capacity of existing water main and proposed water feed. Response: The proposed peak domestic water use for the 48 unit project is approximately 83 gpm based on the International Associations of Plumbing & Mechanical Officials (IAPMO) Water Demand Calculator spreadsheet that uses fixture count and estimated fixture flow rate. We note that this rate is Ms. Amanda Chiancola Re: Juniper Point Investment Co., LLC Page 5 May 21, 2016 somewhat higher than the peak sewage generator rate estimated above. The difference is attributed to the different calculation methods. The 1,500 gpm estimated peak demand for fire protection provided in the Environmental Impact Statement was referring to the site. We have requested information from the City regarding the 12-inch water main in Franklin Street and are awaiting their response. If the City is unable to provide flow test data near the project site, then a hydrant flow test will be conducted and used by fire protection engineer to design the a fire suppression system. A water line looped system will be provided if necessary to provide adequate water supply to the site. 12)Water Valves and Irrigation— Meet with City Engineer to discuss number and condition of existing valves to isolate Franklin Street and incorporate new three-valve connection to Franklin Street. Confirm there is no irrigation planned or provide information about irrigation. Response: A three-valve connection is shown on the revised plans. A water valve is proposed on the new water main and on the north side of the connection on the existing water main. The existing water valve located adjacent to the Franklin Street and Franklin Court intersection will be the third valve. A third water valve can be installed south of the connection if the City prefers that over using the existing valve at the Franklin Street/Franklin Court intersection. A 12-inch by 12-inch by 8-inch cast iron tee will be installed between the water valves. Lawn and landscape areas around the buildings will have a conventional landscape irrigation system, with soil moisture and rainfall sensors. 13)Utility Ownership and Maintenance -Applicant to clarify the statement about private versus public utilities serving the site. Response: The property owner will be responsible for maintenance of the water and sewer service lines located within the Franklin Street right-of-way that serve the property from the main to the property line. The City will be responsible for the maintenance of the existing drain line located on the subject site servicing Franklin Street. A drainage easement is proposed to allow the City to access, maintain or replace this drain line in the future. 14)Sidewalks—Applicant to provide additional information on scope of work for proposed sidewalks on Franklin Street including identifying curb and Ms. Amanda Chiancola Re: Juniper Point Investment Co., LLC Page 6 May 21, 2016 sidewalk material to be used. Applicant to clarify proposed sidewalk width on-site and confirm with City Engineer that 4-foot width is acceptable on Franklin Street. Response: The proposed walkway on Franklin Street will be a 6-foot wide concrete walkway with vertical granite curbing. See Sheet C-3 for the revised sidewalk and curb layout along Franklin Street. 15)Snow Storage. Address potential conflict at fire hydrant. Response: Snow storage is no longer proposed at the location of the proposed hydrant. See Sheet C-3. We trust the above is satisfactory. Should you have any further questions or comments, or require additional information, please do not hesitate to contact the undersigned'. Very truly yours, GRIFFIN ENY. . ROUP, LLC a Robert H. Gri , Cc: D. Knowlton, P.E., City Engineer J. Correnti, Esq. Serafini, Darling & Correnti W. Ross, P.E., New England Civil Engineering, Inc. Enclosures: -Revised Grading and Drainage Plan -Figure 1 Limits of Site Above Flood Waters -Page 12 of Environmental Impact Statement -Water Demand Calculator Spreadsheet -Revised Stormwater Management Report -Environmental Site Assessment by SP Engineering, Inc dated October 2013 (Sent Electronically). 3.0 Public Facilities 3.1 Water Supply Flow Pressure and Distribution. 3.1.a Describe the groundwater and/or surface water supply to be used. Response: Municipal water will be used. Salem obtains water from surface water supplies (Wenham Lake & Ipswich River). 3.1.b Discuss the demands of the project for consumption and fire protection. Response: Assuming full occupancy of the residential buildings, the design demand flow for water consumption is estimated to be approximately 13,200 gallons per day. The peak demand for fire protection for the building is estimated to be approximately 1,500 gallons per minute. The buildings will be equipped with fire suppression sprinklers and hard-wired fire alarm systems. 3.2 Sanitary Sewerage Connection Distribution and Facilities. 3.2.a Discuss the quantity and type of sewage which will be generated by the project. Response: The estimated maximum-day domestic sewage generation is approximately 13,200 gallons/day. 3.2.b Describe the method of sewage which will be generated by the project. Response: Domestic sanitary sewage from the residential units. 3.3 Storm Drainage Facilities 3.3.a Describe where connection to the City system is proposed. Response: The proposed stormwater management system will connect to the existing Salem drainage system, which drains to the North River Canal. 3.4 Disposition of Stormwater 3.4.a Indicate the location of all proposed outfalls. Response: Two new outfalls are proposed to discharge to the North River. Outfall #1 is an 8-inch diameter outfall which discharges clean roof runoff. Outfall #2 is a 15-inch diameter outfall which discharges treated runoff from the site's stormwater management system. Both outfalls will be equipped with rip-rap aprons and tide gates. 3.4.b Describe the effect of the outfalls and their discharge on the receiving waters, i.e., increased flows, pollution etc. Juniper Point Investment Co, LLC Page 12 of 17 August 17,2017 16, 18&20R Franklin Street Redevelopment Rev: May 21,2018 Water Demand Calculator for Estimating Peak Water Demand for Indoor Residential Water Use t, Select Units GPM [H] LPS (A) [B] [Cl [D] [E] FIXTURE ENTER NUMBER PROBABILITY ENTER FIXTURE MAXIMUM RECOMMENDED OF FIXTURES OF USE(%) FLOW RATE(GPM) FIXTURE FLOW RATE(GPM) 1 Bar Sink 0 2.0 1.50 1.50 2 Bathtub 0 1.0 5.50 5.50 3 Bidet 0 1.0 2.00 2.00 4 Clothes Washer 48 5.5 3.50 3.50 5 Combination Bath/Shower 96 5.5 5.50 5.50 6 IDishwasher 48 0.5 1.30 1.30 7 Kitchen Faucet 48 2.0 2.20 2.20 8 Laundry Faucet 0 2.0 2.00 2.00 9 Lavatory Faucet 144 2.0 1.50 1.50 10 Shower,per head 0 4.5 2.00 2.00 11 Water Closet,1.28 GPF Gravity Tank 144 1.0 3.00 3.00 12 Other Fixture 1 0 0.0 0.00 6.00 13 Other Fixture 2 0 0.0 0.00 6.00 14 10ther Fixture 3 0 0.0 0.00 6.00 :Total Number of Fixtures 528 � RfUN�W�ATER� � 90 h.P:ERCENTILE DEMAND FLOW 82 70'' GPM: RESET DEMAND ,rtit �.CAtCULATOR'� Project Name: Tranos- Franklin Street Job No: 1573 Calculated By: M. Paige Date: 5/21/18 (a Authors: Steven Buchberger,(PE), Ph.D.-Professor and Head of Department of Civil Engineering,.Architectural Engineering and.Construction Management, University of Cincinnati Toritseju Omaghomi,PhD Candidate in Environmental Engineering, University of Cincinnati Timothy Wolfe(PE)-Senior Mechanical Engineer,TRC Worldwide Engineering—MEP,LLC Jason Hewitt(PE) -Seattle Office Manager,CB Engineers-P.E.,CPD, LEED AP Daniel Cole -Chair-Sr. Director of Technical Services, International Association of Plumbing and Mechanical Officials(IAPMO). Acknowledgments: Sponsors-International Association of Plumbing and Mechanical Officials(IAPMO),Water Quality Association(WQA),American Society of Plumbing Engineers (ASPE) Code: Developed By Toritseju Omaghomi System Requirements: The Water Demand Calculator is a Microsoft Office Excel file and requires a compatible version of Excel 2009 or later to prevent loss of functionality.This file also uses active content(macros).When downloading this file, Microsoft Office has security features causing a message bar to appear warning that the active content may contain viruses and other security hazards that could harm your computer or your organization's network and that the macros have been disabled. This does not mean that viruses have been detected. It only means that active content has been detected and the user is being warned.Since the source file comes from IAPMO,the file can be trusted and the macros can be enabled.You may need to change the settings in the Trust Center on your computer(find this in the Options section of Microsoft Office applications).Once the file is trusted,the warning will no longer appear.You may also need to check with your company's System's Administrator for security permission to download a file with macros. Disclaimer: Although care has been taken to ensure the accuracy,completeness and reliability of the Water Demand Calculator("Calculator"), IAPMO makes no warranties, express or implied,or representations as to the accuracy of the Calculator. IAPMO assumes no liability or responsibility for any error or omissions in the information contained in or output by the Calculator. IAPMO assumes no responsibility for the consequences of use of such information,nor for any infringement of third party intellectual property rights which may result from its use. Visit IAPMO web site for more information at http://www.iapmo.org/WEStand/Pages/WaterDemandCalculator.aspx MEAN HIGH WATER ELEV. 4.0 NORTH RIVER '2" . J _- y`_2.- - TOP OF COASTAL BANK / (TIDAL) _ - 3— - A,tiW -- / DISCHARGE o j �,\O� . /i % ..�' i1�.�' `� ° \ \ INV=-1.2t/ CB/D it /� / /� /I:' /%"- ��/�� ♦� - ''� � rya. � /� \ rp 11x0 \ �� 0 14 UNITS (FLATS) 1 ..�• B 11x20 /4// 14 UNITS,`(FLATS) 11z20 BTC 9x85 C 9x35 - / /' �\ 11 x3 QSLAB EL. 2.0 I SLAB EL. _'TC lox5o ec loxoo ' '•y No Date Description GRAPHIC SCALE Revisions 11p / 10x5 io eo °°� 10x00 1 r !. - - IN FEET) \ \9x67 - qP%ti, REDUCED SIZE 10xl7' rt . q P I V TC 11 z50 BC 11xo0 SLAB EL. 1 \o TC IOz35 11.3t / 11\.. 10 UNITS (FLATS) ry '� I BC 9x8$ I 'i \�9 Y I N 11 10x7'� \ ,.1.. 35t TALL 3 ,u -. R T. WALL \1 Ot Oy 10x75 ITS +� - , f J % TOW. VARIES i 1 \1 0 5 UN USESL- - x r\77��\ TO`1H� ,� TC 11z30 '/ pt 4 \ `O SLAB EL. ( /� BC 10.80 2-STORY MAP 2N,/F T 471 i�/� '�g°I• 11 E 11.2t I _ - 11 3 TC ltx4 / METAL FRAME CITY OF SALEM �..�4/ a11:,0' 10z33 ` TC 11x22 BC IOx9 BUILDING Griffin l or FURLONG PARK" 1 O 1005 - \ BC to>a72 i -. Engineering 20 FRANKLIN ST 1 c `TC 11.t4 t O• .' / 1 _. � � / Group, LLC ZONE: CONSERVATION \ \\5� ?° ��m BC IOx64-. , USE. PUBLIC PARK 1 11 �,9 I � _ _- 2.0% 1.5% � MAP 26, LOT 403 1 1� N/F 495 Cabot Street 2nd Floor m iox75 q•f / '1. °1• TC 11 z37 CRAIG C. BURNHAM, TRUSTEE BC IOx87 FRANKLIN STREET REALTY TRUST BeveAy,MA 01915 11�\ J o z59, o I0x75 o \� 'N _\se e"'S-- ' : / 14 FRANKLIN ST ZONE: NRCC Tel:978927-5111 USE: COMMERCIAL Fax:978-927-5103 pp I SLAB EL.I I Y p JUNIPER POINT 1'11i� INVESTMENT CO, LLC I I 16-18-20R FRANKLIN ST TC 9x57. = 0 LL---ijl j I\ 5 UNITS D I ' I(b)=4.0s :1 \ ` � ec 9xo7 '...1 I (TOWNHO SES� , II_ SALEM, MA EDMH? \\ p- = 10x4 EC82 R=8.28 v\ 1"' - ' - _ .J .__. _ \_ x - I X4 R 7.64 I(a)=0.0 D •x o m. _ _x -, 1-5,14 1(6)-Lao ', E8C31x3 �is"ca`P--`--r - �L� "_I r.� __ FIGURE 1 TC 8z3 EDMH2 y" 8z73 H?�' O Bc 7xa sx - -Q---��-�-� LIMITS OF SITE ABOVE Bz9 ._ / ° / _ -' - NOTE FLOOD WATERS ~� 8z8' '' b ` ' I— Highlighted Area is above E'0M S \t / 1 Datum. _ _ =elevotion 10-ft NAVD88 POEp p55 EDMH1 �D FRANKLIN _ EDMH ° D ,Bv D D® STREET sr ;N.T.s. '" \\ EDMH' __ _ -�D�_, / s"co'u- / R=7.96 I - .. _ - .c = ._ D D-_�- RD 8.85 VC Job No. _ I P/Pro/salem RCIR--37,69 69 Dat9:4 30 18 / / 120 VVASHINGTON STREET,SUIT£20H P.o:'EOX 3(l26,sALEM;MA 01570 PH:9,78-741.7401. fAk 978:441.7402—VVNlVO:€NGINEERINGCpRPORATIOPa.COM October'l6_2'017 Amanda Chiancoa Staff Planner Office of Plan ning'and Community Development 120 Washington Street Salem, MA 01970 'Re: City of Salem RFQ R-50—On-Call Civil Engineering Support:Services, Task Order No. 29 - Peer Review Services,North River Condo Review, 16, 18,,and20R Franklin Street, Salem;MA Dear Amanda:_ We are pleased tosupport the Salem Planning Board with peer review services for the above referenced Project. We understand the project will be discussed at the upcoming October 19,2017 meeting of your Board and we have prepared-this project status letter for your use at the meeting. Project Understanding The:developer(Juniper Point Investment Company,LLC) proposes a develo,,pmentlredevelopment project at the current site at 16, 18, and.'2OR Franklin Street. The project will involve construction of several buildings;parking lots, and related site work.and utilities. The City of Salem requested an independent peer review of the proposed development plans and documentation including stormwater management, drainage, and on-site engineering issues covered by the Environmental Impact Statement.including garbage, snow storage, etc.. • Included in the peer review will be consideration of existing and proposed utilities, sewer separation and infiltration issues, and adequacy of existing utilities to serve the project. • Peer review will also consider compliance with requirements of the Stormwater Management Permit,North River Canal Corridor Neighborhood Mixed Use District, Flood Hazard Overlay District,special permit. • Specific documents to be reviewed include a Environmental Impact Statement, Stormwater Management Plan and report dated August 2017,a set of Design Drawings (dated 08/17/17. 14 sheets); a set of Architectural Drawings (dated 8/16/17, 9 sheets); and an Application Form for - Flood Hazard Overlay District Special.Permit, Site.Plan Review Application, and Site Plan Review Narrative(none of which have been submitted'for review). The City of Salem has retained a traffic engineer to review the traffic access, egress; and site circulation issues as well as parking so those elements are not inc review. luded as part of this peer WATER RESOURCES - BURIED INFRASTRUCTURE-PUBLIC WORKS - CONSTRUCTION ADMINISTRATION - LAND DEVELOPMENT 1 f Review Comments 1} Submittal Package To date the,following.information has been provided for review: • 08/17/17 set of design drawings(14 Sheets) • 08/16/:17 set of,architectural=drawings (9 Sheets) Flood Hazard Overlay District.Special Permit(3 pages) Stormwater management plan and report dated August2017 Environmental lmpact Statement(EIS) Initial'subriuttal package did not:include site plan review narrative, in support of NRCCNMUD application.:: Status= Ongoing,,Applicahuhas indicated the:set of design drawings.and stormwater management plan will change and final review of these documents relative.to storrnevater should be postponed.. - 2)Flood.Hazard Overlay District Special Permit I. .Proposed use will,comply,to the uses and provisions of the.underlying district Permit narrative indicates"No 2. Adequ'We convenience and safety of vehicular and pedestrian movement within the site and adjacent streets or properties in the event:of flooding. Permit narrative states'`Yes'',however the narrative acknowledges portions of the site and adjacent street will be under water during a 100 year flood event. All proposed building.garage slabs and all parking spaces A411 be at or belowflood elevation 10.0'. All walkways will also beat or below flood elevation 10.0'. We acknowledge that the:adjacent street is also below flood elevation 10.0'. however it is not clear how adequate convenience.for pedestrian and vehicular movement is provided. ® 3. Utilities shrill he located and constructed so as to protect against flooding.. The plans identify a location of proposed transfon-ner near Franklin Street but no spot grades are indicated. Narrative states that transformer will be mounted above flood elevation and all equipment will be located:above:flood elevation. Plans identify locations for gas meters.and HVAC equipment and indicate that the 1 VAC equipment will be located above flood elevations. Request Applicant provide additional information to demonstrate compliance with requirement 2 of the Flood hazard Overlay District Special Permit and revise Sheet C-6 to in clutie spot grades on transformer pad and,building entrance/exit slabs. 3) Proposed Conditions Grading The plans include topographic contours and limited spot grades. However, it is di cult o review the grading relative to proposed walkways and base flood elevation because it is not clear if spot grades :represent top or bottom of curb elevation.. Request applicant provide additional spot grades to identify top and bottom of curb line in areas where they abut walks and structures and spot grades for all slabs at building entrances/exits, and NEW ENGIAND C-ML ENGINEERING CORP. Page 2 of 6 i prepare a plan delineating the limits of the area under'the base flood elevation(6r.confirmation that entire post-development site Will.be at or under flood elevation), 4)Demolition Plan A Demolition Plan was not provided. There are notes on?Shee"t11g...Conditions Plan that identify existing commercial building;pavements,fences, and util.ities".but.there are'"no plans to identify demolition. Request applicant prepare demolition plan"to identify;the.extent of buildings,.foundations; and utilities to be deolished or abandoned on one.draaing"which willfacilitate demolition rarit filing. 5).Contamination-Monitoring Wells There are a number of monitoring wells:shown on Sheet" Section 1.3.a.of`EIS states that some, building roof runoff may be captured and directed into infiltration structures. Request additional information on any related centaniinationlmitigation on the site and impacts on proposed groundwater infiltration. 6) SanitM Sewer Existing serer on.Franklin Street is identified as a 24"RCP sewer that,discharges to North Street. The pipe is:relatively large in diameter but is laid at an extremely flat slope"(05°10 or .0005), so potential. for sedimentation and capacity concerns may exist. Applicant has not provided existing sewer flows (which are likely minimal). Applicant has provided post-development flows of 13",200"gallons per,day in EIS, but has not provided peak post_development sewer flows. Request applicant provide projected post-development sanitary flows for the development(and pfe-development flows if available) and evaluate downstream sewer manholes for evidence of surcharge or accumulated debris that may result,in capacit<ti concerns. 7) Garage Drainage Sheet C-4 identifies five sewer service pipes (garage drains) discharging from garage"levels that connect to four MDC oil/water separator traps. Details for MDC traps identify two exterior vent pipes from each trap but vent locations are not identified on the plans. Request additional information about vent locations because traps are all located within the proposed parking areas or travel lanes and may be in. conflict. Request details on garage drains and vent traps to prevent inundation of City sewer system during extreme flood event when garages are predicted to be under water. Applicant to provide additional detail on oil/water traps and garage drains. 8) Existing Drain An existing drain outfall serving Franklin Street drainage discharges through a portion of the property to the North River. There are no easement.lines indicated on the plans. The plans on C-2 Existing Conditions identify the drain as an.18 VC drain that discharges to a 15"Cl drain downstream which is unconventional and should be confirmed. The next manhole downstream was not opened by the :surveyor and the outfall pipe was not measured so there is some question about the diameter of the pipe to be relocated through the development. A rip rap apron is proposed at the end of the existing drain NEW ENGI.AND C1171L.ENGINEERING C01.1p. Page 3of6 M1 outfall to reduce'erosion of'river bank,but no tide gate is proposed on the existing>drain outfall. Recommend a tide gate be installed to improve drain functionality and reduce sedimentation, to match the controls proposed at the three new dram outfalls.which have rip rap aprons and tide gates proposed. Paragraph I c $ confirms that peak,rate o`f stormwater discharge through existing drain'outfall will increase, and it is,,.n,6ti clear if the increased flaw,rate will:adversely.impact the upstream drainage catchment that also utilizes Ili, & in,9utfail: Request applicazat,confirm the size.of tlie'rain pipe on the property in buried manhole and/or at outfall .and consi'der adding fide gate to outlet to improve performance f . tidally influence drann me. 9)Proposed.Dxain' Based on elevations provided on the plans,the existing City drain -to be relocated)appears to have been constructed-as an inverted siphon bettueen.manholes EDMH1 and EDMH2;presumably"to avoid existing util=ides that are in conflict.. Proposed drain to be rerouted through property as part of this project begins from EDIYIH2.at11 a higher elevationthan the existing discharge pipe from.EDMH2 (.90 versus 2$ feet) Since.the proposed drain rriust cross under or through the utilities that are presumed.to be in conflict with existing drain grade,the,proposed drain grade may also be in cordlct with`the existing utility. Recommend Applicant coin to exploratory excavation to determinethe reason for the existing siphon and i :,proposed',drain;can be installed as designed: Applicant to provide dr"gin easement plan through the development for City, to access, maintain;. or replace the drain ari:the future. 10) Proposed Roof,and.Area Drains Paragraph 3,4.a of EIS states that"1�10 new outfalls are proposed.",however sheet C-.5 identifies three new proposed drain outfalls serving arear drains,,each with proposed rip rap aprons and tide gates. Sheet'C-S ideas#if"ies a number of roof drains that will discharge to the closed drainage syste in, and.a number of additional roof drains that are assumed to discharge onto or into the ground. Paragraph 1.3.a states that some of the roof runoff may be captured and directed into infiltration structures to recharge groundwater,but infiltration structures are not identified on the plans. Further; paragraph 1.3.c.$ states that on-site infiltration of stormwater may not be feasible or advisable due to previous landfill and junkyard activities on site: Applicant to revise Stormwater narrative in, I✓IS to B•etleet plans and confirm that the new proposed outfa"S will not change the stormwater management plan and narrative. Applicant to clarify whether and where roof drainage is proposed to be infiltrated and revise.plans and narrative to be in agreement. Il) Water The plan proposes to utilize an existing 12-inch water main on Franklin Street. Proposed water mains to serve.the five proposed buildings include five new 6=inch fire.services and a new fire hydrant; as well.as three 2-inch and two 4-inch domestic water service feeds. Proposed water use is identified in EIS as 13,200 gallons per day, but peak water demand is not provided. The EIS states that"The peak demand NEW ENGLAND CFVrL ENGINEERING CORP'. Page 4of6 i 1 for.fire protectron,for the building is..estirnated to be approximately 1,500 gallons per minute"; although it is not clear—if this refers to each building or the site. The water main,serving.the property is a 12-inch w. er main from,, 'h Street side,but is connected to smaller 6 inch mains on the Osborne.:Street side, as a result it is not.clear that 1,500 gallons per minute will be available if necessary,particularly when the flow will be needed at the end of a single nori- looped 8-inch water rriaia feed to entire complex. City Engineer requests confirmation that the existing water main has eV40ty19 serve the proposed demands,by-completing fie flow tests or other acceptable means. Recommend 84ineh water main to be looped to Frardcl n to provide increased fire flows if.required. Request applicant to provide additional info rmatton.regarding-proposed peak doanestie water use, clarification on required fire flows for each building and complex,-and condition and capacity of existing water main and proposed water feed,. 12)Water Valves and Irr ation Proposed connection to City water line on Franldiz Street is a:12x8,ztapping sleeve and valve. City typically does not allow tapping sleeves and valves unless.there is.adequate, operable val'ving on each side of proposed connection to allow, development to be isolated from water,service interruption..from either side. 'Plans do not identify irrigation lines or valves, request confirmation there is no proposed irrigation,, Applicant to meet with City Engineer to discuss number and condition o#'existing valves to isolate Franklin Street and incorporate new three=valve connection to Franklin Stree#if recommended. Applicant to confirm there is no,irri", gation planned or provide information about irrigat on. 13.)Utility Ownership and Maintenance Paragraph 4.5;b states that"Approximately 20' to 30' of publicly maintained sewer and water service pipes will run into site from Franklin Street.". Water and sewer services in the street,are owned and maintained by fire properties they serve and not by the City. The only publicly maintained utility on the property would be the main drain serving Franklin Street,after the drainage:easement is established. It is not clear what is the intent of this statement: Applicant to clarify the statement about private versus public utilities servitrg the site. 1:4) Sidewalks Paragraph 4.2.b of EIS states that development will incorporate new four-foot sidewalks with curbing on Franklin Street to,improve consistency of sidewalk and preverit cars from parking on them. Limits of proposed sidewalks are not identified on the plans, request plarrtdentf}ring the proposed sidewalk work including materials used for curbs and sidewalks. City typically requires 5-foot sidewalks where feasible. Plans identify 4-foot and 5-foot sidewalk widths on Sheet C-4 but 4-foot and l0-foot sidewalk Widths on other sheets. Applicant to provide additional information on scope of work for proposed sidewalks on Franklin Street including identifying curb and sidewalk materials to be used. Applicant to clarify proposed sidewalk width on site and confirm vvrthi ,Engineer that 4-foot width is acceptable on Franklin Street. NEW E GLAND CrVIL ENGINEERING CORP. Page 5of6 15) Snow.Storage' On Sheet C-3, snow storage area ,s identified in same location.as proposed fire hvdrarit on Sheet C-4: Applicant'to;revise plans t© address conflict. if you have any°questions or require"additional information,please do not"hesitate to contact me at any hme on my"cell.phone aV978-T67 5415oatm c 401r : f 9 17 . Sincerely, William M.;Ross;P.E. Project"Manager7Pr4ncipal Engineer Ne,w'E and Civil Engineering".Corp; Cc: David Knowlton, City of Salem NEWENGLAND CIATIL ENGINEERING CoRp. Page 6of6 MEAN HIGH WATER OUTFALL #1 / �- - - - - - - -- ELEV. 4.0 W/ DUCKBILL NORTH RIVER -2' - -- � TIDE GATE DRAIN LINE TABLE / _ f - 2 ^INV==4.0t TOP OF COASTAL BANK - _ LINE LENGTH, SLOPE, SIZE, MATERIAL (TIDAL) EROSION / / MNw 3 - FTt % INCH CONTROL - _ - \ FROM TO 5 = - -�\ 5 -= \ \ CB1 DMH1 63.0 1.0 12 RCP g -��_ - - = ��-moons C62 DMH1 2.80 2.0 12 RCP 4-_ -�- \ DMH1 DMH4 23.4 2.0 12 RCP OUTFALL #2 / / /�/` �� / �� _ �� ` \�\S 3\ \ CB3 DMH2 33.7 1.2 12 RCP W/ DUCKBILL nfx / TIDE GATE / / �� //!� / �. J -- --V� �� 6�� \ \ \ CB4 DMH2 2.0 2.5 12 RCP INV=2.4f gxo �, \ GV � ___. ____ �� , y \ \ DMH2 DMH3 54.8 1.0 12 RCP _7 .. �` \ \ \ \ C135 DMH3 2.0 2.5 12 RCP 6»PVC `� � "� �`� \ '�- \� DMH3 DMH4 46.5 1.2 12 RCP CLEAN & CLEAR �--- S=2.4% kQ Io \ 3�2\ DMH4 DMH6 76.8 1.0 15 RCP 8 � DISCHARGE. / --G i �''"--�-� 8 \ INSTALL RIP-RAP 2� /� , - \ (/ AREA DRAIN AD1 �144. �� `\�5 CB6 DMH5 68.3 0.7 12 RCP Jc��l /� \\ RIM=6.5 \ �STge \� Z\\ CB7 DMH5 9.3 3.0 12 RCP 15"VC / "� ��f �O i l / INV(6»PVC)=4.5 ��F \ DMH5 DMH6 57.0 0.7 12 RCP DISCHARGE h p� i �R� DRAIN (AD2) / _� ' ''-- - .� O \ INV=-1.2t / / �% '� `�� 0 /ice RIM=6.5 �� `STQ� \\\ �\ \ C88 DMH6 25.3 1.0 12 RCP cp INV(6»PVC)=4.5 ,� ///� r 9 - 'ROOF DRAIN o "�"SDR21 PVC `� �O�ST \ �} DMH6 DMH7 65.0 0.5 15 RCP s PVC , -- -- J 1 �� / _ •/ / i , L=107.0'f C81 o DMH7 18.0 2.0 12 RCP S-1.0% \ DMH7 DMH8 4.0 2.0 15 RCP DMH8 DMH9 95.9 0.5 15 RCP yx % �// �/ / / / DMH9 OUTFALL 41.0 1.0 15 RCP / // -.- -----f \ �- ._ / CB9 EDMH 37.8 1.0 12 RCP , / O �' 8 // SDR21 PV / C / / ------ -:' -r-- / ROOF DRAIN S=1.0% �� • Z A- of DRAIN ELEVATION TABLE it / .>✓ •/ ♦ / \ ` \\ , ^ STRUCT. RIM, INV.-IN, FT INV.- \ 8 + �� i ,� �� ♦ 11xp �. `, \ `. / FT a b c OUT, FT i xo INV. 5.0t / � ♦ 11 �� Qp, C81 10.35 --- --- --- 6.85 ;_-------_; , `0 �' ,�i` \ I ,` DMH1 10.80 6.22 7.00 7.30* 6.14 \,Qo ��A C62 10.65 --- --- --- 7.06 3 5/21/18 Rev. Drain System from 1 8 INV. 4.7t i _ \�?�,O �9P�q� I j CB3 10.35 --- --- --- 7.35 // DMH6 to River I // / '. / 11x0 ` �.. 1 ,�' i, 14 UNITS FLATS \ys� �' / // CB4 10.30 --- --- --- 7.00 2 4/26/18 Rev. Site Layout DMH8 (FD) ,. / �X'6 - ----'' ( ) \ \9� DMH2 10.44 6.95 6.95 --- 6.87 0 RIM=9.2 I / /` 1 0 l/. I �p 7 \� j CB5 10.50 --- --- --- 7.00 p' 1 8/30/17 Add Grading East of Bldgs; /* ,♦ B 11x20 \ 1 /�/� DMH3 10.64 6.95 6.32 --- 6.24 r DMH7 ( ♦ i' RIM=9.5 / ( 14 UNITS)(FLATS) 11 x20 11 / / �. °' / DMH4 11.30 5.65 5.65 --- 5.57 Add Area Drains AD1, AD2, y / D 1 i DMH1 /� �\ _ �, / CB6 8.43 --- --- --- 4.93 & All Add Outfalls #1, - -- .{_ TC 9x85 RIM=10.8 / \ 11x3 �, (�/ BC 9x35 C87 9.00 --- --- --- 5.50 P-5 --- - I #2, #3; Rev. Roof Leader DMH4 X40 / DMH5 9.20 4.45 5.22 4.37 C810 d'\. �.! ' RIM=11.3 I/ \' - SLAB EL- l� °' Rev. from EDMH1 RIM=8.65 X i I 1 11.3f CB8 9.00 --- --- --- 5.57 Layout, fjt �.• I \ SLAB EL. I D C81 2.0 / DMH6 9.67 4.76 3.97 5.06 3.89 1 to DMH5 to 15" to Match o �,C 10x50 11.5t ` 0 D RIM=10.3 �� / / // DMH7 9.50 3.56 4.79 --- 3.48 Exist. ° \\ B 10x00 D --- ___ „aQ C\ •1bx / ° / / / DMH8 9.20 3.40 3.40 p 1 CB9 8.50 5.0 4.60 No Date Description 1x i b , IM=10 65 I� 11 0' -`' "�� // / CB10 8.65 --- --- --- 5.15 Revisions ° �Al. Vic,•' r DMH9 6.90 4.40 4.00 2.92 2.84 c° �10x50 \ ---'-`D b •M \�e� 8 PVC `��. .---` /, * 8»PVC ROOF DRAIN INVERT-IN ELEV. o p i �\ %, p � +`� i 2� ROOF DRAIN9 ll -o �Oxoo o g L=32.7 r / goo, / / GRAPHIC SCALE R+f' \\ MH6 , ''' Z.p% S=3.0% / / �jA 20 0 to 20 40 so M - RIM 9.67 9x67 / `Oc / / q P qs \ I a ` 10x 7- �i 'x / A / :l / �iq��F M, ROGER � N TC 11 x50 C_5 _ ; GR FFW + 3\- BC MOO SLAB lA 3fL. / ( IN FEET CIVIL y 1 I ♦ B5 10 UNITS FLAT / ' / / 1 inch - 20 , ft. #36686 Q ♦. ° 2M=10.5�CBS ;` : V3 1ox75 RIM=9.0 \ o �-� \ / 3.5 t TALL %1 .` \ �,•� \ 3�% p° o DMH3 / :/ � ' / 1\\ RET. WALL p, 2O9' oD 10x75N,.�s xJ \ ''� b -� RIM=10.6 / // / TOW. VARIES } NOTES: 150 USES"-,- O /� 11x5 1 REFER TO SHEET C-1 FOR NOTES AND C-4 FOR LEGEND. o H.P• ,, OP ,�OwNH� �° TC 11 x30 / / #14 } \� ' \ - \ SLAB EL. I �,� BC 10x80 / 11x / 4� 2-STORY MAP 26, LOT 471 11.2f / � TC 11x4 / METAL FRAME N/F %�°'� 'j � `L• \\� 'r - - BC 10x9 BUILDING CITY OF SALEM d ' �n 10x33 ' CB4 TC 11 22 uriffin "FURLONG PARK» RIM M9 �p \ x o 10x75 / RIM=10.3 BC 1472 /� / off, f �/ Engineering 20 FRANKLIN ST 1 -�'. �1N r - ZONE: CONSERVATION - b� 1 1.5 - - / .2 BC 10x64 \\ �� Group, LLC USE: PUBLIC PARK 1 \ _ _ - - _ • =.0,. 1.5ga \ / MAP 26, LOT 403 _CB7 I as 1 x?5- p 2 D ,D CB3 \ N/F RIM-9.0 �) _ ��: 495 Cabot Street, 2nd Floor ,ate N / �,`.L�: c, p RIM=10. 5 TC 11x37 CRAIG C. BURNHAM, TRUSTEE Beverly, MA 01915 ri 0, ° t / I Bc 1ox87 FRANKLIN STREET REALTY TRUST 40' WIDE JO 1 C-' 25g -8-0 o < �� _�g 1 / 14 FRANKLIN ST '\ "en 10x75 \ _ DRAINAGE I o O EASEMENT H P• I \; \ 1x0 ZONE: NRCC Tel: 978-927-5111 �j 1 , \ `i 1 p \ 1 �` USE: COMMERCIAL PLANTING BED 4� 20' 5' - ENTRANCE BLDG Fax: 978-927-5103 \ � D(�4H2 � N �-'RL Rill=10.44�� / I 1�x 16 BLDG- - -••- ----- =........_ WALK = ROADWAY...... _. CROSS-WALK A.... 1 SLAB EL. .., .. �. \ �0 �" 6 PVC ROOF I 11B �_ I 14 --••••-•-- . -•-.•- = ....... ................. ........ _.......... JUNIPER POINT „ ..__. . 1 ECB1 - �'` \ !� d, LEADER (TYP)\ I +-8 -i ...--•.... ........................ .... s�oPE- O� Q. INVESTMENT CO, LLC 1 I ,. 12 SLOPE R=7.6o \\ MIN S=1.0% y I I ,$ X F- ______ _ ---- CB2 16-18-.20R FRANKLIN ST I(a)=4.15 v` \ - -.- I I \ 5 UNITS p I ..................... ............• -••...... -•-• ................................-•-- •-••••..-z... ...........................-••••-•-••..... .. .... _.. .. ;.. �o TC \ ► `" SALEM MA I(b)=4.05 / , BC 9x07 I (T�WNHbUSES --- \ L - - - -=� , 8 0 8 .....-•-••-••-•••--•-...•. ............. ... .... . .. 1 EDMH1 CB6 1\ -_..--- --'---• � G� X 8x20 - 10x4 I EC62 _ - - . .. .1.2„RCP PIPE.• ._ _. ..: . . � .... : ....... . ._........__...------._..__.._..._._ _...---••--•----.............-----........ .. R=8.28 RIM=8.43 x2� R=7.64 F- -------- _ APPROX. EXIST. GRADE \ -�\ _ .. •• •..... ............. ......-•............ .............................................................. ---- _ x I(0)-00 - _ p °� � ,_•�-- '° -�5;,°��-_:--- .. _.� _- _ __ I- . 4 s .......................................... ............................ ----.... .... _....... . PROPOSED i(b)=1.40 --I- X / ECB1 CPP fix- - - J 8" WATER 8" SEWER....._... TC 8x3 - S - - - 8_ - _ 4 -•---........•-•.................... :�x� ... 4 GRADING & EDMH2 8x73 H.P• 8x9 = O 7C-_7xs - Li-lR=8.28 � ................•--..._..._.....------. - •....................•••......----••----• - -••••--••••----- -- ----- I(a)=3.13 �" . a�./ 8x8 V �� -` DRAINAGE I(b)=2.0 �Sy \ / / 0 I(I()a 28 ' ==' CB9 PGCES R 0+10 0+20 0+30 0+40 0+50 0+54 i RIM=8.5 NO 0� EDMH1 ° �e D � �- ' \ � / FRANKLIN S TR 0+00 sc�1% 1'=20' EDMHZ c 18 p c p ,� \ EET _- - - -9 _ _ _ ° D 1� VC SECTION A-A Job o _ 1 "=5' R=7.96 - '- - -- _ ..-_ -._. D R=8.85 C- 5 File Name: PAP ro/solem I(a)=2.17 D ro salem CON C•51D EC 3 / B� I(b)--3.5 R=7.69 R 7.75 - _________ _ D� 8/17/17 / 1 3.50 I(c}=2.96 I=3.69 - ______-- 1 Stormwa ter 1 Management 44�� Plan under the Massachusetts Stormwater Management Regulations 9 g Residential Development 1 16, 18, & 20R Franklin Street Salem, MA 1 � G Ss -4Y ,rs.}` August 2017 REVISED: May 2018 Rim Applicant: Juniper Point Investment Company, LLC r t r IRECE,IVE 1 Submitted to: MAY 23 18 E �A City of Salem, MAC DEFT. OF PIANNLNC & COMMUNlry pEVELyp r f DO Prepared by: Griffin Engineering d. , M 3 °� � :. Beverly, MA �. f 1 TABLE OF CONTENTS ' Stormwater Management Checklist ' Attachment A Project Description 1.0 INTRODUCTION............................................................................................................ A-1 ' 1.1 Existing Conditions................................................................................................ A-1 1.2 Proposed Conditions...........:................................................................................. A-2 ' 2.0 STORMWATER MANAGEMENT STANDARDS ........................................................... A-3 2.1 Standard 1: No New Untreated Discharges........................................................... A-3 2.2 Standard 2: Peak Rate Attenuation....................................................................... A-3 2.3 Standard 3: Recharge........................................................................................... A-3 2.4 Standard 4: Water Quality..................................................................................... A-4 2.5 Standard 5: Land Uses With Higher Potential Pollutant Loads.............................. A-4 2.6 Standard 6: Critical Areas ..................................................................................... A-4 ' 2.7 Standard 7: Redevelopment Projects and Other Projects Subject to the Standards only to the Maximum Extent Practicable.................. A-5 2.8 Standard 8: Construction Period Pollution Prevention and Erosion and ' Sediment Control...................................................................... A-5 2.9 Standard 9: Operation and Maintenance Plan....................................................... A-6 2.10 Standard 10: Prohibition of Illicit Discharges ....................................................... A-6 ' 3.0 SUMMARY..................................................................................................................... A-6 ' Attachment B Stormwater Computations B.1 -Water Quality Volume Calculations B.2 -Water Quality Flow Calculations B.3 -Test Borings August 2013 by SP Engineering, Inc B.4 -TSS Removal Calculation Worksheets B.5 -TSS Removal Efficiency Curve (by Hydro International) Attachment C Long-Term Pollution Prevention Plan ' Attachment D Operation and Maintenance Plan Attachment E Illicit Discharge Statement ' Attachment F Proprietary Separator Third-Party Evaluation 1 STORMWATER MANAGEMENT ' CHECKLIST t 1 1 1 1 1 ' Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program Checklist for Stormwater Report ' 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,use only the tab p ort(the Stormwater Re which should provide more substantive and detailed information) but is offered 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. re 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. ' Z 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. Stormwater-Checklist.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. rRegistered Professional Engineer Block and Signature OF MqS S ROBERT �y o H. En CIVIL #36686 � 57 Z/-i�f ' Signature and Date ' Checklist Project Type: Is the application for new development, redevelopment, or a mix of new and redevelopment? ' ❑ New development ❑ Redevelopment ® Mix of New Development and Redevelopment Stormwater-Checklist.doc•04/01/08 Stormwater Report Checklist•Page 2 of 8 ' Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program Ll Checklist for Stormwater Report Checklist (continued) LID Measures: Stormwater Standards require LID measures to be considered. Document what environmentally sensitive design and LID Techniques were considered during the planning and design of I ' the project: ❑ No disturbance to any Wetland Resource Areas ® Site Design Practices(e.g. clustered development, reduced frontage setbacks) I ' ® 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. Stormwater-Checklist.doc•04/01/08 Stormwater Report Checklist•Page 3 of 8 ' Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program Checklist for Stormwater Report ' Checklist (continued) Standard 2: Peak Rate Attenuation ' ® Standard 2 waiver requested because the project is located in land subject to coastal storm flowage and stormwater discharge is to a wetland subject to coastal flooding. ❑ Evaluation provided to determine whether off-site flooding increases during the 100-year 24-hour storm. ❑ Calculations provided to show that post-development peak discharge rates do not exceed pre- development rates for the 2-year and 10-year 24-hour storms. If evaluation shows that off-site flooding increases during the 100-year 24-hour storm, calculations are also provided to show that post-development peak discharge rates do not exceed pre development rates for the 100-year 24- hour storm. ' Standard 3: Recharge ' ❑ Soil Analysis provided. ❑ Required Recharge Volume calculation provided. - No ' ❑ 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 I ❑ 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. Stormwater-Checklist.doc•04/01/08 Stormwater Report Checklist•Page 4 of 8 ' Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program Ll Checklist for Stormwater Report Checklist (continued) Standard 3: Recharge (continued) ❑ The infiltration BMP is used to attenuate peak flows during storms greater than or equal to the 10- year 24-hour storm and separation to seasonal high groundwater is less than 4 feet and a mounding ' analysis is provided. ❑ Documentation is provided showing that infiltration BMPs do not adversely impact nearby wetland resource areas. Standard 4: Water Quality The Long-Term Pollution Prevention Plan typically includes the following: • Good housekeeping practices; • Provisions for storing materials and waste products inside or under cover; • Vehicle washing controls; ' Requirements for routine inspections and maintenance of stormwater BMPs; • Spill prevention and response plans; • Provisions for maintenance of lawns, gardens, and other landscaped areas; • Requirements for storage and use of fertilizers, herbicides, and pesticides; ' Pet waste management provisions; • Provisions for operation and management of septic systems; • Provisions for solid waste management; • Snow disposal and plowing plans relative to Wetland Resource Areas; • Winter Road Salt and/or Sand Use and Storage restrictions; • Street sweeping schedules; • Provisions for prevention of illicit discharges to the stormwater management system; • Documentation that Stormwater BMPs are designed to provide for shutdown and containment in the event of a spill or discharges to or near critical areas or from LUHPPL; • Training for staff or personnel involved with implementing Long-Term Pollution Prevention Plan; • List of Emergency contacts for implementing Long-Term Pollution Prevention Plan. ® A Long-Term Pollution Prevention Plan is attached to Stormwater Report and is included as an attachment to the Wetlands Notice of Intent. ❑ Treatment BMPs subject to the 44%TSS removal pretreatment requirement and the one inch rule for calculating the water quality volume are included, and discharge: ❑ is within the Zone II or Interim Wellhead Protection Area ❑ is near or to other critical areas ' ❑ is within soils with a rapid infiltration rate(greater than 2.4 inches per hour) ❑ involves runoff from land uses with higher potential pollutant loads. ❑ The Required Water Quality Volume is reduced through use of the LID site Design Credits. ® Calculations documenting that the treatment train meets the 80%TSS removal requirement and, if applicable, the 44%TSS removal pretreatment requirement, are provided. Stormwater-Checklist.doc•04/01/08 Stormwater Report Checklist•Page 5 of 8 LIMassachusetts Department of Environmental Protection Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 4: Water Quality (continued) ' ® The BMP is sized (and calculations provided) based on: ❑ The '/2" 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 Lhas approved for stormwater discharges to or near that particular class of critical area. ❑ Critical areas and BMPs are identified in the Stormwater Report.. Stormwater-Checklist.doc•04/01/08 Stormwater Report Checklist•Page 6 of 8 ' Massachusetts Department of Environmental Protection Bureau of Resource Protection -Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 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. ',I , ❑ 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. t ® A Construction Period Pollution Prevention and Erosion and Sedimentation Control Plan containing the information set forth above has been included in the Stormwater Report. Stormwater-Checklist.doc•04/01/08 Stormwater Report Checklist•Page 7 of 8 i ' Massachusetts Department of Environmental Protection Ll Bureau of Resource Protection - Wetlands Program Checklist for Stormwater Report Checklist (continued) Standard 8: Construction Period Pollution Prevention and Erosion and Sedimentation Control (continued) ❑ The project is highly complex and information is included in the Stormwater Report that explains why it is not possible to submit the Construction Period Pollution Prevention and Erosion and ' Sedimentation Control Plan with the application. A Construction Period Pollution Prevention and Erosion and Sedimentation Control has not been included in the Stormwater Report but will be submitted before land disturbance begins. ❑ The project is not covered by a NPDES Construction General Permit. ❑ The project is covered by a NPDES Construction General Permit and a copy of the SWPPP is in the Stormwater Report. ® The project is covered by a NPDES Construction General Permit but no SWPPP been submitted. The SWPPP will be submitted BEFORE land disturbance begins. Standard 9: Operation and Maintenance Plan ® The Post Construction Operation and Maintenance Plan is included in the Stormwater Report and includes the following information: ' ® Name of the stormwater management system owners; ® Party responsible for operation and maintenance; ® Schedule for implementation of routine and non-routine maintenance tasks; ® Plan showing the location of all stormwater BMPs maintenance access areas; ® Description and delineation of public safety features; ® Estimated operation and maintenance budget; and ® Operation and Maintenance Log Form. ❑ The responsible party is not the owner of the parcel where the BMP is located and the Stormwater Report includes the following submissions: ❑ A copy of the legal instrument(deed, homeowner's association, utility trust or other legal entity) ' that establishes the terms of and legal responsibility for the operation and maintenance of the project site stormwater BMPs; ❑ A plan and easement deed that allows site access for the legal entity to operate and maintain BMP functions. Standard 10: Prohibition of Illicit Discharges ® The Long-Term Pollution Prevention Plan includes measures to prevent illicit discharges; ❑ An Illicit Discharge Compliance Statement is attached; i ® NO Illicit Discharge Compliance Statement is attached but will be submitted prior to the discharge of any stormwater to post-construction BMPs. Stormwater-Checklist.doc•04/01/08 Stormwater Report Checklist•Page 8 of 8 f 1 1 1 1 ATTACHMENT A PROJECT DESCRIPTION 1 1 1 1 1 1.0 INTRODUCTION This stormwater management report is prepared in support of the proposed site redevelopment and construction of a residential development at 16, 18, and 20R Franklin Street in Salem, MA. The drainage system has been designed in accordance with the Massachusetts Department of Environmental Protection (MassDEP) Stormwater Management Standards. 1.1 Existing Conditions The site is approximately 2.27-acres in size and is made up of three parcels. The project site has been used for automobile fueling, servicing and the Ferris Junkyard since the mid-1950's. The October 2013 Environmental Site Assessment (ESA) by SP Engineering, Inc.' states that the property was a municipal landfill prior to becoming a junkyard and that the site is largely filled tidelands. The landfill use is ' also described as occupying fifty-percent or more of the property and the adjacent park (Furlong Park; owned by the City of Salem); and was operated by the City of Salem between approximately 1906 and 1930. The landfill received wastes such as municipal ash, demolition debris, and leather wastes. The adjacent Furlong Park was remediated by the City of Salem as part of park improvements in approximately 2010. A Release Abatement Measure Plan (RAM) was submitted in February 2011 for park remediation under DEP Release Tracking Number (RTN) 3-29262.2 The site primarily has a gravel and dirt surface with little vegetation present. Some on-site roadways are paved. The extent of pavement within the junkyard could not be precisely determined due to the stored vehicles. We estimated that 25% of the interior area was pavement. Mature deciduous trees (ash, oak, maple, and locust) exist along the southern property boundary and within the parcel near the northern parcel boundary. Stored vehicles were removed a few years ago from the approximately 50-ft wide strip of land along the North River. That area is now sparsely vegetated with grasses and weeds. A one-story garage and office structure is located on the west side of the project site adjacent to Franklin Street. ' The topography of the site is relatively level terrain with only two feet of grade change across the site above the coastal bank. The highest point lies at the northwest corner of the site which drains southeast towards the North River. A soil 1 Phase Two Environmental Site Assessment at 18 Franklin Street, Salem,MA prepared by SP Engineering, ' Inc. of Salem,MA. October 2013. z Release Abatement Measure Plan for Furlong Park Soil Excavation and Removal at 20 Franklin Street, Salem MA prepared by TRC Environmental Corporation of Lowell,MA dated February 2011 (Mass DEP RTN 3- 29262). ' A-1 berm along the North River bank appears to prevent junkyard runoff from draining directly into the river. iThe FEMA Firm Flood Map shows that the site is located within a Zone "AE" Flood Hazard area (Elevation 10-ft; NAVD 1988 datum, reference: FEMA FIRM Map No. 25009CO419G dated July 16, 2014). Zone "AE" Flood Hazards are defined as areas subject to inundation by the 100-year.flood event, with known base flood elevations. The entire property is located within the AE flood zone. 1.2 Proposed Conditions The project involves redevelopment of the junkyard site located along the North River on the south side of Franklin Street between Furlong Park and the Burnham Dredging Company operation at 14 Franklin Street. The plans call for construction of five residential buildings providing a total of 48 dwelling units. The proposed project includes site remediation as directed by the project Licensed Site Profession, and complete removal of the Ferris Junkyard and associated car repair and maintenance facilities within the property. Near the residential buildings, a pergola/patio, landscaping and on-site parking will be installed. The proposed project also includes construction of a public access walkway and landscaping along the North River waterfront. Site plans showing the proposed redevelopment and stormwater management system have been separately provided. The proposed project is a mixture of new development and redevelopment. When complete, there will be approximately 52,620 square feet of impervious surfaces at the site. This exceeds the current amount of impervious surfaces (26,480 square feet) by approximately 26,140 square feet. In other words, approximately 50% of the site impervious surfaces are considered "new" development and 50% are considered redevelopment. Stormwater runoff from the "new" development area will fully meet all 10 DEP Stormwater Management Standards except standard 3 (recharge). The project intentionally does not include a recharge component due to the site landfill and junkyard history. Stormwater runoff from the redevelopment portion of the site will meet the DEP Stormwater Standards to the maximum extent practicable. The proposed project significantly improves existing drainage conditions by capturing and treating runoff from approximately 81% of the proposed walkways and parking area (23,413 sq. ft.) prior to discharging to the North River. Runoff from the proposed building roofs (23,600± sq. ft.) is considered clean and does not require ttreatment. Roof runoff is directed away from the municipal drain line where practicable. Approximately 88% of the impervious surfaces on-site are in full compliance with the Standards (except Standard 3, for reasons described above), which exceeds the requirement for redevelopment at this site. ' A-2 r 2.0 STORMWATER MANAGEMENT STANDARDS 2.1 Standard 1: No New Untreated Discharges No new untreated discharges to wetlands or waterways are proposed. Two new outfalls are proposed to discharge to the North River. Outfall #1 is an 8-inch diameter outfall which discharges clean roof runoff. Outfall #2 is a 15-inch diameter outfall which discharges treated runoff from the stormwater management system on- site. Both outfalls will be equipped with rip-rap aprons and tide gates. 2.2 Standard 2: Peak Rate Attenuation A waiver from Standard 2 applies because the project is located in land subject to coastal storm flowage; the stormwater discharge is to the tidal North River. 2.3 Standard 3: Recharge The United States Department of Agriculture Natural Resources Conservation Service Soil Survey characterizes the soil as Urban Land, which indicates that the soils have been significantly altered or obscured by urban works and structures. Four soil borings installed in August 2013 by SP Engineering, Inc. confirmed the presence of fill materials in all of the soil borings. The fill contained ash, soil fill materials, brick and leather to approximately 4-ft to 7-ft below grade. This is consistent with the reported landfill use of the site. Natural soils found below the fill materials were described as grey-sand and silts which we classified in the "C" hydrologic soil group. Groundwater was encountered within the fill layer at 3-ft to 6- ft below grade. Due to the landfill and junkyard uses of the site, high groundwater table, and ' location adjacent to a site (Furlong Park) that is known to contain contaminated soils and has the same landfill history as the subject property, installing an infiltration device to meet the MassDEP recharge volume requirement number 3 seems tpotentially more harmful to the environment than beneficial. According to the 2013 ESA by SP Engineering, Inc., the site has been exposed to hazardous materials associated with its historical filling, use as a municipal landfill, and junkyard operations. Furlong Park has soils that were classified as contaminated and required remediation under the MCP program to reduce potential risks to park patrons from soils containing metals and PAHs associated with historical urban fill. Installing an infiltration device in on-site fill materials may mobilize pollutants in the fill and may cause or contribute to groundwater contamination. The potential loss of annual recharge associated with not meeting Standard number 3 at this site will not have a significant environmental effect: there are no downstream wetland areas that would benefit from additional recharge nor is there a need for additional groundwater contributions to this portion of the North River, as might exist in a non-tidal river or at a site that occupied a larger portion of a watershed. The adjacent Furlong Park is documented as containing contaminated A-3 r soil conditions, so additional groundwater contribution from this site would not be beneficial to that property or its downstream areas. ' At this site, Standard No. 3 is met to the maximum extent practicable. For the reasons described above, and to the benefit of the local environment, recharge devices are not proposed. 2.4 Standard 4: Water Quality The minimum required water quality treatment volume for the project site is the first half inch of runoff from impervious surfaces. The proposed stormwater treatment system is designed to provide a weighted average of approximately 85.2% TSS removal. The reader is referred to Water Quality Volume Calculations provided in Attachment B. The water quality volume is satisfied by a First Defense (FD) proprietary separator pretreatment device. The FD pretreatment device at the site is predicted to achieve an annual 96% TSS removal rate. The FD directs flow to the North River. The ' proprietary separator was sized to adequately treat the required water quality volume by converting the WQV to an equivalent peak flow rate. Additionally, existing catch basins adjacent to the site in Franklin Street will be cleaned and retrofitted with hoods to improve their performance. Computations for the proposed proprietary separator are provided in Attachment B. The equivalent Water Quality Flow (WQF) rate calculation was performed in accordance with MassDEP guidelines. The calculated WQF rate was used with the manufacturer's TSS Removal Efficiency Curve to estimate the annual TSS removal. The efficiency calculations were based on third-party evaluations of the First Defense proprietary separators. The third-party evaluations are provided in Attachment F. As required by the Stormwater Management Standards, a Long-Term Pollution Prevention Plan has been prepared for the project and is provided in Attachment C. The plan identifies suitable practices for source control and pollution prevention throughout the useful life of the site. 2.5 Standard 5: Land Uses with Higher Potential Pollutant Loads In accordance with the Massachusetts Stormwater Management Standards, the proposed primary site use is not considered a Land Use with Higher Potential Pollutant Load (LUHPPL). Therefore, this standard does not apply. 2.6 Standard 6: Critical Areas The project site is not tributary to an environmentally-critical area as defined by the Massachusetts Stormwater Management Standards. Therefore, this standard does not apply to this project. A-4 r 2.7 Standard 7: Redevelopment and Other Projects Subject to the Standards only to the Maximum Extent Practicable The site has been previously developed with a one-story garage and office structure, and the junkyard. Existing surfaces are primarily gravel, dirt, and pavement. The 26,140 sq. ft. increase in impervious surfaces at the site is considered new development and the remaining portion (26,480 sq. ft.) of the project site is redevelopment. The proposed project will improve existing conditions at the site. The project will remove the industrial use at the site eliminating several sources of pollutants. Approximately 43,700 sq. ft. of junkyard will be replaced with vegetation such as lawn and planting beds. The stormwater management system will capture and treat approximately 23,400 sq. ft. of proposed parking and walkway surfaces prior to discharging to the North River. The proposed buildings will replace approximately 23,600 sq. ft. of junkyard and will have clean roof runoff discharging towards the North River. In total, approximately 90,700 sq. ft. (92%) of the project site will be improved by eliminating pollutant sources and providing pretreatment to stormwater runoff. Additionally, existing catch basins in Franklin Street adjacent to the site will be cleaned and retrofitted with hoods and the existing 15-inch diameter discharge to the North River will be cleaned and a rip-rap apron will be installed. All of the proposed work area meets standards 1, 2, & 4 through 10 except for approximately 6,144 sq. ft. of proposed walkways and roof area located adjacent to Franklin Street and North River. These areas are considered "de minimus" under the criteria listed in the Massachusetts Stormwater Management Handbook. Prior to site redevelopment, stormwater runoff from approximately 1,970 sq. ft. of existing pavement drains to the Franklin Street municipal drainage system. The project increases the amount of impervious area tributary to these Franklin Street municipal catchbasins by approximately 886 sq. ft. The existing catch basins in Franklin Street will be improved by cleaning and installing hoods to better provide stormwater treatment; however the improved catchbasins will not meet a 80% TSS removal standard. Due to the small size of this area, and its location downstream of the project, the de minimus provision applies. 2.8 Standard 8: Construction Period Pollution Prevention and Erosion and Sediment Control Consistent with the NPDES Construction General Permit requirements, a Stormwater Pollution Prevention Plan (SWPPP) is required for any project resulting in over 1-acre of land disturbance. The proposed project anticipates approximately 2.27-acres of land disturbance. Therefore, a SWPPP will be prepared and submitted to the issuing authority prior to land disturbance commencing. A-5 2.9 Standard 9: Operation and Maintenance Plan An Operations & Maintenance Plan has been provided in Attachment D. The owners of the land are responsible for the system operation and maintenance. 2.10 Standard 10: Illicit Discharges ' The submitted Long-Term Pollution Prevention Plan (Attachment C) specifies measures to prevent illicit discharges from entering the stormwater management system. Source control and response plans are also specified to prevent illicit discharges from being conveyed through the stormwater management system. Since the project site has been previously developed, a signed Illicit Discharge Compliance Statement cannot be provided at this time. A component of the proposed project includes abandoning existing utilities from the industrial buildings and site. Consistent with the Massachusetts Stormwater Handbook, the property owner will submit a signed Illicit Discharge Compliance Statement prior to discharging any stormwater runoff to the post-construction stormwater BMP's. A draft copy of the Illicit Discharge Statement is provided in Attachment E. 3.0 SUMMARY The proposed drainage system and site redevelopment plans for the residential development at 16, 18 AND 20R Franklin Street conforms to MassDEP Stormwater Management Regulations. The proposed drainage system will treat and remove TSS and other pollutants throughout the project area and minimize erosion. Proper construction and operation and maintenance of the proposed drainage system are critical to its long-term performance. To that end, an Operations and Maintenance Plan and Long-Term Pollution Prevention Plan have been prepared and will be instituted throughout the facility's life. I 1 A-6 L 1 1. 1 1 1 ATTACHMENT B STORMWATER COMPUTATIONS 1 1 1 � 1. 1 B.1 - Water Quality Volume Calculations B.2 - Water Quality Flow Calculations B.3 - Test Borings August 2013 by SP Engineering B.4 - TSS Removal Calculation Worksheets B.5 - TSS Removal Efficiency Curve (by Hydro International) r Griffin Engineering Group, LLC 495 Cabot Street, Suite 2 Beverly, MA 01915 Phone:978-927-5111;Fax:978-927-5103 WATER QUALITY VOLUME CALCULATION Job Name: Tranos-Franklin Street Job No: 1573 Date 8/25/2017 Revision: 5/18/18 Designer MBP Checked By: RHG REQ. WATER QUALITY VOLUME(WQV) DEPTH= 0.5 inch(s)of runoff WEIGHTED AVERAGE TSS REMOVAL CALCULATION Total Area Pavement Roof WQV %TSS Imp.Area x Tributary Subcatchments* Treatment Train (so (sf) (socf) Removal TSS P1 to P8, P10, Bldg A, Bldg D, &Bldg E 39,336 23,413 11,560 1,457 96% 33,574 First Defense P9 1 3,859 1 2,123 1 733 1 119 1 25% 714 jDe minimus Areas P11 &P12 33,355 3,288 1 98 141 25% 847 IDe minimus Areas Total: 76,550 28,824 1 12,391 85.2% 35,135 See Subcatchment Plan DR-2 in Attachment D. 1 Weighted Calculations: Average WQV= Imp.Area x 0.5-inch x 1-foot/1 2-inches Weighted Average%TSS Removal=Total Imp.Area x TSS/Total Imp,Area Notes: 1)Stormwater runoff from the roof(Subcatchments Bldg B&Bldg C) is omitted from the weighted average calculations unless routed through the Water Quality Structure. MassDEP considers roof runoff to be clean. 2)The WQV for the First Defense Proprietary Separator was converted to a WQF per MassDEP requirements. (See Water Quality Flow Calculations) 3) Refer to Attached TSS Removal Efficiency Curve Prepared by the Manufacturer, Hydro International for the First Defense Proprietary Separator. Removal efficency is calculated based on the WQF. 4)The proposed impervious areas from Subcatchments P9, P11, &P12 are considered"de minimus" under the criteria listed in the Massachusetts Stormwater Management Handbook. 5)Subcatchments P13& P14 contain no significant impervious surfaces so they were omitted in the weighted average calculation III Page 1 of 1 B.1 Griffin Engineering Group, LLC ' 495 Cabot Street, Suite 2 Beverly, MA 01915 r Phone:978-927-5111;Fax: 978-927-5103 WATER QUALITY FLOW CALCULATIONS Job Name: Tranos- Franklin Street Job No: 1573 Date: 8/25/2017 Revision: 5/18/18 Designer: MBP Checked By: RHG PROPRIETARY SEPARATORS REQ. WATER QUALITY VOLUME (WQV) DEPTH = 0.5 inch(s) of runoff i Structure Name Imp. Area A z t,(min.) t,(hrs.) qu Q,.o Proposed Proposed (sf) (miles ) (csm/in) (cfs) Device Configuration DMH8(FD#1) 34,973 0.00125 6.0 0.10 774 0.485 4' FD Online Notes: Qo.5 = (qu)(A)(WQV) where: QO.5= flow rate associated with first 0.5-inch of runoff(WQF) qu =the unit peak discharge in csm/in A= impervious surface drainage area in square miles WQV=water quality volume in watershed inches (0.5) DMH3 (FD#1) - FIRST DEFENSE PROPRIETARY SEPARATOR Internal Bypass Configuration Bypass Flowrate= 0.7 cfs (Per Manufacturer) WQF = 0.49 cfs -> OK Page 1 of 1 B.2 <_ •: M tm LEW M3 M. FRANKL N-1""- r Former '+Y� Tannery yam rRL / TrucY. Parking Fence � OMw-I Garage Parking a ! g Fence t City of Salem Burnham Marine � �t ~ ' \ (Liner White �' Contractors Truck with �' _ \ iI Metal x _ u w-2 waste oil _ sS'I ., � ,_.�( M f gas tonksi � � I-1 and antifreeze 0 / / f O I (Liner i Ballfield/Playground — 1 o , �a`r1 � I . ForeGo TB $� / Car /' Stripping Rack I cG� o0 0 MW-6 // Storago !) t li e TB= TEST 80Re m � \�°one Grossy-� ,�' nC C 1 / i I j MW=MONITORING Swale �� l �ha�„ Low Spot 1, t I 0 WELL e/ ! �' i + SS= SURFACE < Oi �/ I/ ` / t ! Fence SAMPLE x ! / ()Tees I I Prop.Line SS-2 / 1 I 1 �\ow Spot *TB--{ MW-5 Access Road -+rg-3 i Buf er Storm 1 6. Drain NORTH Tf xsS-3 ' SITE PLAN RIVER ° 'q� FERRIS AUTO SERVICE (Tidal ) CT\ TOpofBank 16-20 FRANKLIN ST. SALEM,MA SPINC. 9 10-13 / �' FIGURE TWO i DEPTH TB-1 West Burnham LOCATION TB-2 center property (Feet) MW-5 56' from River MW-3 54' from River ' HNu HNu Coarse gravel, 0 Coar a gravel 0 Small rock 1 Gravel, red fiber Grey stone, glass 0 ' 2 Grey stone ash + gravel 0 ' 3 orange ash, grey ash coal cinders, wet 0 2 ' Blk/ re ash, wet 0 0 4 grey 5 brick then loose, 0 Blk silt, ash, sand, rock 1 Blk silt oily smell 6 1 7 1 8 Blk silt + sand 0 ' Greyash wood 0 9 Green clay ' ' 10 M 0' screen grey/green uniform sand 5' solid MW-3 10 screen ' Riser 5' solid 11 15 Riser z 15 Soil Logs ' Ferris Auto Services 18 Franklin St. Salem, MA DEPTH TB-3 Ballpark NE LOCATION TB-4 waste fluid storage (Feet) NM-4 52' from River MW-6 center west property ' HNu HNu 0 Tan, brown gravel 0 Pave I + stone 0 1 Tan sand + rock, concrete ' 0 ' 2 Blk grit, 0 Grey fine sand 0 Brick and concrete ' 3 Blk sand and silt 0 1 4 Blk silt + filer 0 Red bark ' S Blk silt, wood, 0 Red bark 0 Ash, cinder 6 7 8 fine/med sand + rook 9 Gravel, Blk stone, wet 0 0 wet !� 0 MW-4 10 10' screen Fine grey sand 5' solid Riser MW-6 ' 11 1 10' screen Grey silt + clay Grey clay 5' solid Z12 15 15 Roadbox Soil Logs ' Ferris Auto Services- 18 Franklin St. Salem, MA INSTRUCTIONS: Non-automated:Mar.4,2008 1. Sheet is nonautomated. Print sheet and complete using hand calculations. Column A and B: See MassDEP Structural BMP Table 2. The calculations must be completed using the Column Headings specified in Chart and Not the Excel Column Headings 3. To complete Chart Column D, multiple Column B value within Row x Column C value within Row 4. To complete Chart Column E value, subtract Column D value within Row from Column C within Row 5. Total TSS Removal=Sum All Values in Column D Location: North of"Bldg D;(DMH;8) A B C D E TSS Removal Starting TSS Amount Remaining BMP1 Rate' Load* Removed B*C) Load (C-D) First Defense:Proprietary:_! Separator 96% 1.00 0.96 0.04 � L 0 ?j Cn -E-+ C� V Separate Form Needs to be Completed for Each Total TSS Removal - 96% Outlet or BMP Train PrOjeCt: Tranos 9SiMasonStreet Prepared By: MiBP *Equals remaining load from previous BMP (E) Date May 20"18 which enters the BMP Hydro International s t o r m w a t e r 4-ft Diameter First Defense 100% Removal Efficiency Curve* 96%I1 90° --------' /o r------- r--------r------ I I 1 I 1 ° 1 1 1 I I 70°/O ' ' ' ' I I -__-____�_____-_ �_____---� -1___--_--� I I C I I I 1 v --------' 1 I I 1 I 60/o r------- r--------T------ -T--------4--------i----- ------ , 1 V1 ---------1--------- I I I 1 1 1 1 50% W ' 1 1 ? ' 1 By ass flow rate=0.7 cfs S40% ' ' ' I I I 1 1 1 1 1 , o 'Note: R utts are based on the M inc 20% -------- 1 ------------------ Der 2rtment of Environmenta I Protection Tes Jng Protocols-(Available Upon Request) I I 1 1 10% ----------------- «- *__---_ -+__-_-_-- _-----+- __�----_--- ___ ------_ -_-_ -------- I I 1 I 1 1 1 I I 0% I I I I I I I I I 0 0.1 2 0.3 0.4 0-5 0.0 0.7 0.8 0.9 1 � �� low rate(cfs) Q=0.19 cfs L_`1(3--6b T' Q = 0.67 cfs Hydro International • 94 Hutchins Drive • Portland, ME 04102 Tel: (207) 756-6200 • Fax: (207) 756-6212 www.Hydro-International.biz ATTACHMENT C LONG TERM POLLUTION ' PREVENTION PLAN 1 1 1 1 1 1 Long Term Pollution Prevention Plan Standard #4 of the MA DEP Stormwater Management Handbook requires that a Long ' Term Pollution Prevention Plan (LTPPP) be prepared and incorporated into the long term operation and maintenance plan of the projects stormwater management system. The ' purpose of the LTPPP is to identify potential sources of pollution that may affect the quality of stormwater discharges and to describe suggested practices to reduce pollutants in stormwater discharges. Good housekeeping practices-The subject property owner is to keep the site in a neat and orderly condition so that pollutants are not conveyed to the storm drainage system or ' the North River. Materials swept, blown or washed into the storm drains or can decrease the system's effectiveness and could eventually be conveyed into the North River. Some examples of good housekeeping practices are pavement sweeping, litter control, ' contained outdoor waste and cigarette disposal receptacles, and protected material storage areas. The property owner should provide proper training and assign responsibilities to personnel to keep the site in a neat and orderly condition. ' Provisions for storing materials and waste products inside or under cover—A trash and recycling disposal company(s) hired by the owner will pick up waste materials and properly dispose of them at a state approved disposal facility. The proposed trash and recycling receptacles located within the first floor garage areas will be properly maintained and emptied at least once a week. ' The stormwater drainage system has catchbasins with hooded outlets and deep sumps designed to capture and retain trash, debris, oils, and sediments. Downstream of the ' catchbasins but before the stormwater outfalls, proprietary separator is also installed to further intercept trash, debris, oils, and sediments that might have entered the stormwater drainage system. ' Vehicle washing controls—Outdoor vehicle washing has the potential of conveying wash water with heavy concentrations of detergents and sediments into the stormwater ' drainage system. The project site does not include any designated vehicle washing areas, nor is it expected that vehicle washing will take place on-site. ' Requirements for routine inspections and maintenance of stormwater BMP's- Consistent with Standard 9 of the Massachusetts Stormwater Management Regulations, an Operation and Maintenance Plan has been provided in the Stormwater Management ' Report. The plan details routine inspection and maintenance of the stormwater BMP's along with associated record keeping forms. ' Spill prevention and response plans— Sources of potential spill hazards include vehicle ' 16, 18, & 20R Franklin St. August 2017 LTPPP-1 1 fluids and fuels, pesticides, paints, solvents, and liquid cleaning products. These exterior spill hazards have the potential to enter the stormwater drainage system and are to be addressed as follows: 1) Spill hazards of pesticides, paints, and solvents shall be remediated using the Manufacturers' recommended spill cleanup protocol. ' 2) Vehicle fluid and fuel spills shall be remediated according to local and state regulations governing fuel spills. 3) The property owners shall have the following equipment and materials on hand to address a spill clean-up: brooms, dust-pans, mops, rags, gloves, trash bags, trash containers, and absorptive materials such as sand, sawdust, or kitty litter. ' 4) Spills of toxic or hazardous materials shall be reported to the Massachusetts Department of Environmental Protection at 1-888-304-1133. Provisions formaintenance of lawns garden and other landscaped areas- It should be a general goal of the subject property owner to achieve a high-quality, well-groomed and stable landscape that evolves throughout the seasons and protects the overall condition of the property. All landscaped areas are to be maintained with dense vegetative growth or a layer of mulch so as to minimize sediment transport. Litter and waste is to be removed weekly from the landscaped areas and adjoining parking lots and disposed of ' properly. Requirements for storage and use of fertilizer, herbicides and pesticides - Fertilizers, ' herbicides, and pesticides are not to be stored on site or within the buildings. Should use of some become necessary, application should be performed by a state licensed contractor in accordance with the manufacturer's label instruction and when ' environmental conditions are conducive to product application Pet waste management provisions-All pet waste is to be scooped up, sealed in a plastic bag, and disposed of properly in the garbage. Pet waste should never be deposited in the stormwater management system for it contains high level of fecal coliform bacteria. ' Provisions for operation and management of septic systems—There are no septic systems associated with the project site. The sanitary sewer is proposed to be connected to the city sewer main in South Mason Street & Buffum Street Extension. Snow disposal and deicing chemicals—Snow will be stockpiled on site within open space areas until the stockpile areas become a hazard to the daily operation of the site. At that ' point, snow is to be disposed of at an off-site location. It will be the responsibility of the hired snow removal contractor to properly dispose of transported snow according to the Massachusetts DEP, Snow Disposal Guidelines. It is the responsibility of the snow ' removal contractor to follow these guidelines and all applicable laws and regulations. ' 16, 18, & 20R Franklin St. August 2017 LTPPP-2 r The property owners, or hired,building maintenance company, will be responsible for the clearing of the sidewalks and building entrances. The owner may be required to use a rde-icing agent such as salt or potassium chloride to maintain a safe walking surface. The de-icing agent for the walkways and building entrances may be kept on site in a designated storage room within the building. De-icing agents are not to be stored outside. 1 1 r 1 r r r r r r r ' 16, 18, & 20R Franklin St. August 2017 LTPPP-3 1 r 1 1 1 1 1 1 1 ATTACHMENT D � ' OPERATION & MAINTENANCE t PLAN 1 1 1 1 1 1 1 1 OPERATION & MAINTENANCE PLAN System Owner: Juniper Point Investment Co., LLC r O&M: Party Responsible for The owner shall be responsible for the construction phase and the long-term operation and maintenance of the stormwater management system as outlined in this Operation and Maintenance (O&M) Plan. Should ownership of the property change, the succeeding owner shall assume all responsibilities for implementing this Operation and Maintenance Plan. Emergency Contact Information: • Salem Fire & Police (Emergency) 911 • Salem Fire Department (Business) 1-978-744-6990 ' • Salem Police Department (Business) 1-978-744-0171 • Salem Conservation Commission 1-978-619-5685 • Salem Health Department 1-978-741-1800 • Salem Public Works Department 1-978-744-3302 • Salem Engineering Department 1-978-619-5673 • Mass DEP (Emergency Response) 1-888-304-1133 ' • Mass DEP (Northeast Regional Office) 1-978-694-3200 Note: The system inspectors should note that drainage pipes, catchbasin, manholes, ' and treatment devices are considered "confined spaces"subject to strict OSHA standards regarding safe entry. Confined spaces present inherent hazards to workers. Only appropriately trained staff with appropriate safety equipment and monitors may enter confined spaces, and then only with a specific entry permit. Also, this work may pose hazards to workers, such as soft ground, flowing or standing water, snakes and rodents. Again, only appropriately trained staff with the necessary safety equipment should undertake such work. Phase I: Construction Period Operation and Maintenance Plan Following is the general sequence of anticipated construction events: 1) Install proposed erosion controls and construction entrance(s). ' 2) Abandon all existing on-site utilities, demolish existing building, and perform any required clean-up on-site such as removing litter, automobile parts, etc. ' O&Mplan.docx August 2017 Revised: May 2018 1 3) Clear site and grub areas as they become necessary. ' 4) Perform all remediation activities on-site such as removal of all landfill material from the proposed building footprints. i5) Excavate and install the Building A foundation. Backfill foundation to bring site to rough grade. Repeat for Buildings B through C. 6) Install all water, sewer, and drainage lines and structures within the parking area. Install conduit for electrical service. (Note: Do not install frame and grates/covers on the sewer drainage structures until the fine grading phase. Provide large metal plates over the precast openings and bury as required.) 7) Excavate and install the Building D & E foundations. Backfill foundations to bring site to rough grade. 8) Install building utility services. Gas company to install gas main, services, & meters. 9) Bring site to finish grade. Install frame and grates/covers to finish grade. Vacuum all precast drainage structures and install and maintain geotextile filter fabric in all catchbasin grates until final paving. ' 10)Install bituminous pavement binder course. 11)lnstall curbing, sidewalks, and landscaping. 12) Install final pavement, signage and striping. Installing and maintaining comprehensive erosion controls during construction is critical to the protection of the environment and the proposed drainage system. Following is a list of erosion control measures to be taken to protect the existing Salem drainage system and the proposed drainage system during construction. 1) Install haybales and silt fence downhill of all proposed work area as shown on the Grading and Drainage Plan (Sheet C-5). 2) Install the construction entrance(s) at entrance off of Franklin Street. i3) Temporary soil stockpiles shall be encircled with haybales and stabilized with erosion control matting or temporary seeding, depending upon the proposed duration. 4) Stabilize all disturbed areas as soon as practicable. Provide temporary O&Mplan.docx August 2017 Revised: May 2018 2 stabilization of soil to be exposed for a long period of time (i.e. one month). I ' 5) Install erosion control matting on all proposed vegetated slopes greater than 3:1 (H:V). 6) All erosion control measures are to be inspected weekly and after each rainfall event. Additional erosion control materials (i.e. haybales, silt fence, filter fabric) are to be kept on site and readily accessible as required. 7) Sediment accumulation up-gradient of the haybales and silt fence greater than 6" in depth shall be removed and disposed of in accordance with all applicable regulations. 8) The stabilized construction entrance(s) shall be inspected weekly. The entrance(s) shall be maintained by adding additional clean, angular stone to remove the soil from the construction vehicle tires. If soil is still observed leaving the site from construction vehicle tires, adjacent roadways shall be kept ' clean by street sweeping. 9) Dust shall be controlled using on-site water trucks as required. 10) All erosion control measures shall be maintained, repaired or replaced as required or directed by the owner's engineer, the City Engineer, or the City Conservation Agent. 11) The contractor shall comply will the Erosion Control Notes listed on the project drawings (Sheet C-1). Part II: Long Term Operation and Maintenance Plan The stormwater management system is a series of catch basins located at low points ' within the paved parking lot. Stormwater collected by the catch basins is conveyed through a proprietary stormwater device prior to discharging to the existing municipal drainage pipe that crosses the subject site. ' Stormwater runoff from the buildingrooftop is collected b utters and/or scuppers and p Yg conveyed by downspouts and roof leaders to the sites drainage system. Roof runoff from a portion of Buildings #2, #3 & #4 are discharged overland within areas of lawn. To ensure optimal performance of the stormwater management system, routine inspections and maintenance should be done at frequencies specified below. An Operation and Maintenance Plan Schedule form is attached documenting compliance. Paved Parking Surfaces—As part of normal site clean-up and as discussed in the Long Term Pollution Prevention Plan, debris is to be removed from the parking lots O&Mplan.docx August 2017 Revised: May 2018 3 1 as it accumulates. Weekly patrolling for litter is recommended. Sand from winter ice and traction control should be removed semi-annually (ie. during early spring and late fall). Significant oil leaks should be swept up and disposed of using oil-absorbent materials as they are discovered. Any oil spills or leaks that reach the catchbasins must be reported to the Massachusetts DEP oil spill hotline. Catchbasins & Drain Manholes - Remove the grate or cover and visually inspect for corrosion and structural damage. Inspect pipe inlets and bottoms for signs of infiltration or inflow. The grate or cover and hoods on the catchbasins should be inspected on a quarterly basis during the first and year and semi-annual thereafter. Cleaning of the catchbasins should be done on a yearly basis and by a vacuum truck or clamshell. The contractor is to take care to avoid damaging the catchbasin hood. While cleaning, if a layer of oil is observed floating on the water surface, place an oil-absorbent pillow on the surface, allow to soak and remove. ' Repeat this process until the oil layer is removed. Alternatively, have the oil layer pumped out by a licensed disposal contractor and appropriately disposed of. The oil absorbent pillows must be drummed for disposal by a licensed disposal ' contractor. Area Drains— Remove the grate and visually inspect for corrosion and structural damage. The grate and replaceable filter bags should be inspected on a monthly basis during the first year and quarterly thereafter. Cleaning the area drain sumps should be done on a yearly basis. The contractor is to take care to avoid damaging the area drain. First Defense Stormwater Treatment Device—A copy of the manufacturer's Operation & Maintenance Manual is provided at the end of this section which contains the required operation and maintenance procedures for the treatment devices. The devices should be inspected for corrosion and structural damage on ra quarterly basis during the first year and semi-annually thereafter. The device also should be cleaned on a yearly basis and in accordance with the manufacturer's procedural recommendations. Snow Storage Area—The parking lot has been designed with snow storage areas 9 p 9 9 g along the edges while maintaining reasonable travel lanes and parking areas. In the event of significant snow accumulation, snow can be placed in the grassed area in the southerly portion of the site. Debris from melted snow shall be cleared form the site and properly disposed of at the end of the snow season or no later ithan May 15rn O&Mplan.docx August 2017 Revised: May 2018 4 ' 1 lydro International w� a a Y� 5 Fr.La �4 Operation and Maintenance Manual r First° Defense Stormwater Solutions Vortex Separator for Stormwater Treatment Turning Water Around ...® 1 Page 2 First Defense®Operation and Maintenance Manual Table of Contents 3 First Defense®by Hydro International -Benefits of the First Defense® -Applications -First Defense®Components 4 Operation -Introduction -Pollutant Capture and Retention -Wet Sump ' -Blockage Protection 4 Maintenance -Overview -Determining Your Maintenance Schedule 5 Maintenance Procedures -Inspection -Floatables and Sediment Cleanout 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 plc'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 First Defense° by Hydro International Capturing more than 25 years of separation design Benefits of the First Defense® experience, the First Defense®is Hydro International's latest Compact and flexible design addition to its family of hydrodynamic vortex separators -Can be used as a catch basin inlet and directional intended for stormwater applications. It has been developed change manhole with ease of installation and maintenance at the forefront -Optional one or two inlets ' without sacrificing performance or design flexibility. -Does not require a bypass structure •Hydrodynamic Vortex Separation All internal components are housed in either a 4-ft or 6-ft -Extended and structured flow path diameter precast manhole that is designed to withstand traffic -Minimal headloss -Reduces turbulence and re-suspension loads. Each model can be used as a catch basin inlet or -Reverse-flow outlet intake prevents short-circuiting standard manhole with solid cover so that runoff can enter -Improved efficiency for all flows from an overhead grate, inlet pipe or both without diminishing Delivered Pre-assembled for easy and fast installation performance. Simple to inspect and maintain • Independently verified The First Defense®has internal components that are designed to generate rotational flow within the device Applications without requiring a tangential inlet. Flow within the precast New developments and retrofits chamber is controlled to prevent turbulence and its unique Utility yards reverse-flow outlet intake ensures a longer retention time Streets and roadways by preventing short-circuiting. An internal bypass prevents Parking lots high flow re-suspension and washout and eliminates the Pre-treatment for filters, infiltration and storage need for additional bypass structures. The internals can Industrial and commercial facilities easily be adjusted to change the angle between the inlet Wetlands protection and outlet for storm drain directional changes and dual inlets can be accomodated in most cases. This simplifies grading ' and site design so that flow can be conveyed from isolated locations within the same site without increasing the number of structures. ' For removal of fine sediment and associated pollutants, oil spills,trash and debris,the first choice in stormwater treatment systems is the First Defense®. ` R First Defense®Components 1. Built-In Bypass 2. Inlet Pipe 3. Inlet Chute 4. Floatables Draw-off Port(not pictured) 5. Outlet Pipe 6. Floatables Storage 7. Outlet Chute 8. Sediment Storage Page 14 First Defense®Operation and Maintenance Manual Sam Operation Maintenance Introduction Overview The First Defense®operates on simple fluid hydraulics. It is self- The First Defense®protects the environment by removing a wide activating,has no moving parts, no external power requirement range of pollutants from stormwater runoff. Periodic removal of and is fabricated with durable non-corrosive components. these captured pollutants is essential to the continuous, long- No manual procedures are required to operate the unit and term functioning of the First Defense®. The First Defense®will maintenance is limited to monitoring accumulations of stored capture and retain sediment and oil until the sediment and oil pollutants and periodic clean-outs. The First Defense®has storage volumes are full to capacity. When sediment and oil been designed to allow for easy and safe access for inspection, storage capacities are reached,the First Defense®will no longer monitoring and clean-out procedures. Neither entry into the be able to store removed sediment and oil. Maximum.pollutant unit nor removal of the internal components is necessary for storage capacities are provided in Table 1. maintenance,thus safety concerns related to confined-space- entry are avoided. Pollutant Capture and Retention The internal components of the First Defense®have been P designed to optimize pollutant capture. Sediment is captured �' s i and retained in the base of the unit,while oil and floatables are v= ' stored on the water surface in the inner volume. The pollutant storage volumes are isolated from the built-in bypass chamber MP to prevent washout during high-flow internally-bypassed storm - events. Accessories such as oil absorbant pads are available for Max Oil Oil enhanced oil removal and storage. Due to the separation of the . Storage Depth � N oil and floatable storage volume from the outlet,the potential for washout of stored pollutants between clean-outs is minimized. Wet Sump The sump of the First Defense®retains a standing water level between storm events. The water in the sump prevents stored Sediment l� Sediment sediment from solidifying in the base of the unit. The clean- Storage out procedure becomes more difficult and labor intensive if the system allows fine sediment to dry-out and consolidate. Dried sediment must be manually removed by maintenance crews. This is a labor intensive operation in a hazardous environment. Fig.1 Pollutant storage volumes in the First Defense®. 1 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 The First Defense®allows for easy and safe inspection,monitoring Inspection and clean-out procedures. A commercially or municipally owned Inspection is a simple process that does not involve entry into the sump-vac is used to remove captured sediment and floatables. First Defense®. Maintenance crews should be familiar with the Access ports are located in the top of the manhole. First Defense"and its components prior to inspection. Maintenance events may include Inspection, Oil & Floatables Removal, and Sediment Removal. Maintenance events do not Scheduling require entry into the First DefenseO, nor do they require the • It is important to inspect your First Defense"every six months internal components of the First Defense"to be removed. In the during the first year of operation to determine your site-specific case of inspection and floatables removal, a vactor truck is not rate of pollutant accumulation. required. However, a vactor truck is required if the maintenance event is to include oil removal and/or sediment removal. • Typically, inspection may be conducted during any season of the year. Determining Your Maintenance Schedule ' The frequency of cleanout is determined in the field after Recommended Equipment installation. During the first year of operation, the unit should be ° Safety Equipment and Personal Protective Equipment inspected every six months to determine the rate of sediment and (traffic cones,work gloves, etc.) floatables accumulation. A simple probe such as a Sludge Judge" can be used to determine the level of accumulated solids stored in - Crow bar or other tool to remove grate or lid the sump. This information can be recorded in the maintenance log (see page 9)to establish a routine maintenance schedule. • Pole with skimmer or net The vactor procedure, including both sediment and oil/flotables - Sediment probe(such as a Sludge Judge") ' removal, for a 6-ft First Defense" typically takes less than 30 minutes and removes a combined water/oil volume of about 800 • Trash bag for removed floatables gallons. First DefenseO Maintenance Log Table 1.First Defense"Pollutant Storage Capacities and Maximum Cleanout Depths 4 180 <23.5 202 26 202-342 6 420 <23.5 626 36 626-1,046 NOTE The total volume removed will depend on the oil accumulation level. Oil accumulation is typically much less than sediment, however removal of oil and sediment during the same service is recommended. Page 16 First Defense®Operation and Maintenance Manual Inspection Procedures kg .. 1. Set up any necessary safety equipment around the access port or grate of the First Defense®as stipulated by xq local ordinances. Safety equipment should notify passing � $ 'pedestrian and road traffic that work is being done. . A4 �� 2. Remove the grate or lid to the manhole. F. � J . 3. Without entering the vessel, look down into the chamber to inspect the inside. Make note of any irregularities. Fig.2 shows the standing water level that should be observed. ` 4. Without entering the vessel, use the pole with the P skimmer net k to remove floatables and loose debris from the outer annulus b of the chamber. 5. Using a sediment probe such as a Sludge Judge®, measure CAUTIONI r the depth of sediment that has collected in the sump of the AVOID INLET CHUTE �v vessel. �E 6. On the Maintenance Log(see page 9), record the date, unit t location, estimated volume of floatables and gross debris gym: removed, and the depth of sediment measured. Also note P<� any apparent irregularities such as damaged components or blockages. 7. Securely replace the grate or lid. .N 8. Take down safety equipment. xis : 9. Notify Hydro International of any irregularities noted during ........ inspection. Fig.2 Floatables are removed with a vactor hose. Floatables and Sediment Cleanout Floatables cleanout is typically done in conjunction with sediment removal. A commercially or municipally owned sump-vac is used Recommended Equipment to remove captured sediment and floatables(Fig.2). • Safety Equipment(traffic cones, etc) Floatables and loose debris can also be netted with a skimmer ' Crow bar or other tool to remove grate or lid ' and pole. The access port located at the top of the manhole I ' 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 • Floatables typically and sump cleanout are conducted once Vactor truck(flexible hose recommended) Y a year during any season. • First Defense®Maintenance Log • Floatables and sump cleanout 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. 4. Remove oil and floatables stored on the surface of the watery with the vactor hose(Fig.2)or with the skimmer or net(not pictured). 5. Using a sediment probe such as a Sludge Judge®, measure CAUTION! the depth of sediment that has collected in the sump of the AVOID INLET CHUTE . vessel and record it in the Maintenance Log(page 9). Kee yv 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.3). z ' 7. Retract the vactor hose from the vessel. 8. On the Maintenance Log provided by Hydro International, 1 record the date, unit location,estimated volume of floatables and gross debris removed,and the depth of sediment z , measured. Also note any apparent irregularities such as damaged components, blockages,or irregularly high or low ................................................................................_._._.._.._.....__....----..__.....---..._...._..-----..__._._...__....-.._...---- water levels. Fig.3 Sediment is removed with a vactor hose 9. Securely replace the grate or lid. Maintenance at a Glance 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 cleanouts it is not necessary to remove the entire volume of liquid in the vessel. Only removing the first few inches of oils/floatables and the sediment storage volume is required. Hydrom 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: i. INSTALLATION DATE: MODEL SIZE (CIRCLE ONE): 4-FT 6-FT INLET(CIRCLE ALL THAT APPLY): GRATE 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 Hydro First Defense° Inspection and International 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 i f 1 1 1 1 1 1 1 1 1 1 1 i ' Hydro International(Stormwater), 94 Hutchins Drive, Portland ME 04102 Tel: (207)756-6200 Fax: (207)756-6212 Web:www.hydro-int.com 1 1 1 1 1 1 1 1 ydro :�� International What is HX? HX is Hydro Experience, it is the essence of Hydro. It's ' interwoven into every strand of Hydro's story, from our products to our people,our engineering pedigree to our approach to business and problem-solving. HX is a stamp of quality and a mark of our commitment to optimum process performance.A Hydro solution is tried, tested and proven. There is no equivalent to Hydro HX. R,- 1 -:i��ltl ,ice,I�aSs'�:. mwater v � = � Stor Solutions 94 Hutchins Drive Portland, ME 04102 Tel: (207)756-6200 Fax: (207)756-6212 stormwaterinquiry@hydro-int.com www.hydro-int.com q Turning Water Around...® FD_O+M_B1209 OPERATION & MAINTENANCE PLAN SCHEDULE Project: Tranos- Franklin Street Project Address: 16, 18, &20R Franklin Street Date: 8/25/2017 Party Responsible: Juniper Point Investment Co., LLC Annual Maint. Budget: $5,200 Task Description/Schedule Maintenance Est. Annual Inspection Activity Maint. Cost Date: Inspector: Perform sweeping of paved parking areas and walkways Sweep, power Street Sweeping after spring thaw to remove any traction sand applied broom, or vacuum during the winter months. Also, perform sweeping during paved parking lots $2,000 late fall to remove any leaf litter and debris. and walkways Catchbasins & Drain Inspect grates, covers, and hoods quarterly for the first year and semi-annual thereafter. Also, inspect pipe ipe inlets Vacuum Deep Manholes and precast structures for infiltration and inflow. Sump Annually $1,250 First Defense Water Inspect covers, inlets, and plastic insert quarterly for the Quality Treatment first year and semi-annual thereafter. Clean yearly per Vacuum Deep $350 Devices Manufacturers' recommendations Sump Annually Inspect grates and replaceable filter bags are to be None unless Insp. Area Drains inspected monthly during the first year and quarterly Warrants $600 thereafter. Also, inspect pipe inlets and structures for Otherwise infiltration and inflow. Debris from melted snow shall be cleaned form the site Snow Storage Area(s) and properly disposed of at the end of the snow season Clean Annually $1,000 (by May 15th). ATTACHMENT E ' ILLICIT DISCHARGE STATEMENT 1 1 1 1 1 1 1 1 f ' ILLICIT DISCHARGE COMPLIANCE STATEMENT I verify that no illicit discharges exist on the 16, 18, & 20R Franklin Street properties. Through the implementation of Long Term Pollution Prevention Plan and Operation and Maintenance Plan, measures are set forth to prevent illicit discharges from entering the ' stormwater management drainage system. ' Signature Print Name Date Title Company Signature Print Name Date Title Company ' Note: This certification must be signed before stormwater is conveyed to the proposed stormwater drainage system in accordance with Standard 10 of the Massachusetts Stormwater Management Standards. r t ' ATTACHMENT PROPRIETARY SEPARATOR THIRD-PARTY EVALUATION FOR FIRST DEFENSE 1 i i i 1 1 1 Hydroil 1 International r m w a Stormwater S t te r www . h y d ro - international . biz 1 First DefenseO 1 Performance Evaluation i 1 For submission to the Massachusetts Stormwater 1 TechnologyEvaluation Project MASTEP J � ) 1 Stormwater Technology Clearinghouse 1 February, 2011 1 1 1 Hydro International stormw ate r First Defense° Performance Evaluation Summar y Hydro International successfully completed First Defense® laboratory testing to assess washout retention and SSC/TSS removal efficiency. Test procedures were based on NJDEP and WI DNR protocols. Performance evaluation included varying flow rates up to 200% of the Maximum Treatment Flow Rate (MTFR) and varying influent concentrations using OK-110 silica sand, with 50% pre-loaded sediment sump. Positive removals were achieved for all flows and concentrations, with greater than 70% ' SSC/TSS efficiency based on the NJDEP weighted removal efficiency calculation method. Non- detectable (<4 mg/L) SSC and TSS effluent concentrations and over 90% sediment retention indicated that no detectable washout had occurred. These findings indicate that washout would be minimal even with a larger MTFR or a shallower sump design. Alternatively, it is reasonable to expect that finer particle sizes with lower settling ' velocities would be retained and not washed out at the tested flow rates. BYPASS OUTLET k �l Iq d INLET iFLOATABLES STORAGE INLET' ` CHUTE OUTLET CHUTE FLOATABLi S DRAW-OFF-PORT 4 ar SEDIMENT STORAGE ' Figure 1: First Defense®- Internal components and flow path 9 p ©2011 Hydro International Performance Evaluation— First Defense® Internati ro onal storinwater Introduction The First Defense® is an enhanced vortex separator designed to remove floating and settleable pollutants commonly found in stormwater runoff. A key feature of the First Defense is an internal Bypass Chute (Figure 1) that allows treatment without requiring additional flow-diversion structures and prevents scour velocities from re-suspending captured pollutants. The MTFRs are 0.7 cfs and 2.2 cfs for the 4-ft and 6-ft diameter models, respectively. Internal weirs are set to ensure all flows up to the MTFRs can be treated without bypass. This laboratory-based test program was conducted to evaluate the overall system performance while accounting for variable inlet concentrations and sediment retention over a wide range of loading rates. Test Objectives The First Defense was tested utilizing protocols that met or exceeded the most recent recommendations by testing authorities, including NJDEP and WIDNR. Objectives included: • Determine the MTFR using washout as the limiting factor. • Quantify washout at 125% and 200% of the MTFR by measuring the maximum effluent concentration and maximum allowable reduction in sump load. • Determine the Suspended Sediment Concentration (SSC) and Total Suspended Solids (TSS) removal efficiency for inlet concentrations of 50 mg/L, 100 mg/L, and 200 mg/L at 25%, 50%, 75%, 100%, and 125% of the MTFR, with the sump filled to 50% of the 1 maximum storage volume. • Determine the weighted removal efficiency based on the calculation method described in the NJDEP protocol for laboratory testing of hydrodynamic sedimentation devices. • Provide independent witnessing during testing to validate and confirm procedures described and followed in this report. ' • Validate TSS and SSC analytics by outsourcing samples to an independent, state- certified laboratory. In an effort to satisfy regulations that require results reported according to TSS procedures, results of this study included both TSS and SSC analysis. Recent settleable solids performance ' evaluations are reporting percent removal of SSC with a general consensus that SSC methods can improve the accuracy and repeatability of measurements for samples that have relatively high sediment settling velocities. ' ©2011 Hydro International Performance Evaluation— First Defense® Page 2 of 8 ro !F International Storrnwater Test System Description ' The distribution of the test material, US Silica OK-110, is shown in Figure 2. Approximately 20% of the particles are less than 75 pm with the remaining 80% are between 75 and 150 pm. ._._........ ........... _.. ' 100 80 =-------------- --- s �- 60 -...-—--- 80% 75-150 microns 40aj - -----—------ c a 20 ------ ' — — — 20% <75 microns 0 —---r _ 0 50 100 150 200 250 ' Particle Size µm Figure 2: Test sand particle size gradation (OK-110) A full-scale First Defense with 4-ft diameter vortex chamber was tested at Hydro International's state-of-the-art hydraulics laboratory in Portland, ME. Clean water from a 23,000-gallon reservoir was pumped using an 8-inch variable Flygt pump at targeted flow rates through a pipe network to the First Defense (see Figure 3). Dosing equipment delivered a slurry of the OK-110 test material to the First Defense. Grab samples were collected at the inlet sampling point and effluent pipe. Effluent was discharged back into the reservoir. ©2011 Hydro International Performance Evaluation- First Defense® Page 3 of 8 ro Xional S10r "11Wo1er I. ' Sediment Probe Slurry Mix m Bypass Chute Effluent Sample Point Y , r�& x Outlet Chute Influent Sample Point y Inlet Chute 3"Sediment False Bottom 10"Support Figure 3: Cutaway diagram of test setup with false bottom, sediment probe and internal components Washout Test Procedure The sediment storage sump was pre-loaded to 50% maximum storage volume by depositing greater than three inches of OK-1 10 on a false floor 10 inches from the sump bottom (Figure 3). The sediment depth was measured with a sediment probe at thirteen locations, evenly spaced over the sump bottom, and averaged to determine initial sediment depth. Clean water from the reservoir was pumped to the First Defense vortex chamber at the target flow rate of 0.88 cfs for 125% of the MTFR. After the flow had stabilized, water was pumped to the test unit for a period of 15-minutes. At the conclusion of the test period, the sediment depth was re-measured and compared to the initial depth. After determining that greater than 90% of the pre-loaded volume remained in the sump, washout testing using effluent sampling was initiated. The pump was restarted at the target flow rate of 0.88 cfs, and influent and effluent samples were collected after the flow rate had stabilized. For a test period of 25 minutes, influent and effluent samples were collected at five- minute intervals, resulting in six paired samples, which were analyzed for SSC by ASTM D3977 ' Method B and TSS by APHA SM2540D. The test was repeated for the flow rate of 1.4 cfs or 200% of the MTFR. A representative from the University of New Hampshire Stormwater Center observed all of the tests as an independent witness and reviewed data analysis and quality control procedures of the external laboratory used for sample analysis. 1 ©2011 Hydro International Performance Evaluation—First Defense@ Page 4 of 8 ro!F I nternationa) SiormWC, Irer Removal Efficiency Test Procedure The sediment storage sump was pre-loaded to 50% maximum storage volume by depositing greater than three inches of the test sand on a false floor 10 inches from the sump bottom. Clean water from the reservoir was pumped to the First Defense vortex chamber. The five target flow rates were 25%, 50%, 75%, 100%, and 125% of the MTFR. Background influent and effluent samples were collected to ensure clean water supplied from the reservoir did not exceed non-detect concentrations of 4 mg/L for SSC/TSS. A slurry mixture dosing system (see Figure 4) was used to obtain the variable influent concentrations of 50 mg/L, 100 mg/L and 200 mg/L for the target flow rates. The required mass of test sand was mixed with clean water in a 60-gallon barrel to form the slurry, which was continually stirred to keep the mixture in suspension. The slurry was pumped at a constant rate from the mixing barrel to a dosing port located upstream of the First Defense using a peristaltic pump. The first influent sample was collected after displacing three test volumes, or three residence times within the vessel. Four additional influent samples were collected at one- minute intervals. 1 Slurry Mixer 60 Gallon Mixing Barrel Peristaltic Pump Figure 4: Slur Mixture g Slurry Dosing System ' The first effluent sample was collected one residence time after collection of the first influent sample. Four additional effluent samples were collected at the same time interval, for a total of five repeats. The test was repeated for three influent concentrations at five flow rates, for a total ' of 150 influent and effluent samples collected for 15 test runs. Dosing was ceased after collection of the last effluent sample. Another set of influent and effluent background samples was collected one residence time after the peristaltic pump had stopped and sediment was no longer entering the system. The influent and effluent samples were analyzed for SSC by ASTM D3977 Method B and TSS by APHA SM2540D. ©2011 Hydro International Performance Evaluation— First Defense® Page 5 of 8 Hydroll International storm oter A representative from the University of New Hampshire Stormwater Center observed 20% of the tests as an independent witness and reviewed data analysis and quality control procedures of the external laboratory used for sample analysis. Twenty percent of the SSC samples for the removal efficiency testing were analyzed by an external laboratory and all TSS samples were analyzed by an external laboratory. Washout Test Results and Discussion The ability of the First Defense to retain sediment solids was evaluated in two ways: 1. Measure the reduction in the sediment sump level prior to and following testing at operating rates of 125% and 200% of the MTFR with the sump 50% pre-loaded, and 2. Measure the effluent concentrations with the sump 50% pre-loaded with sediment at operating rates 125% and 200% of the MTFR. The goal of the first part of the washout testing was to demonstrate that less than 10% of the sediment was reduced (i.e. show greater than 90% of the sediment was retained). Sediment depths were determined by averaging the depth measurements taken from 13 sampling locations within the sump. Sampling locations were replicated for each flow rate with the intent of monitoring changes in depths throughout the sump. Although the initial sediment depth was approximately three inches as measured from the false floor, additional sediment was deposited throughout the test program resulting in sediment depths greater than three inches. However, for both flow rate tests, the difference in average sediment depth prior to and following testing ' remained the same and all measurements were greater than three inches. The goal of the second part of the test was to demonstrate that effluent concentrations did not exceed 10 mg/L at operating rates of 125% and 200% of the MTFR. As seen in Table 1, at 50% of the sediment capacity, the effluent concentrations were below the analytical detention limit of 4 mg/L for both TSS and SSC for flow rates of 125% and 200% of the MTFR. Percent of Influent Flow Effluent EMC m /L MTFR cfs SSC TSS 125 0.88 Non detect Non detect 200 1.4 Non detect Non detect ' Overall, the First Defense met or exceeded the test requirements to show no measurable effluent TSS or SSC concentrations, as well as retaining greater than.90% of the pre-loaded sediment, at both 125% and 200% of the MTFR. ©2011 Hydro International Performance Evaluation — First Defense® Page 6 of 8 Hydrol International Oorrnwc. Ier ' Removal Efficiency Test Results and Discussion Removal efficiency data was based on a total of 150 influent and effluent samples collected from 15 test runs at five target flow rates and three target inlet concentrations. Each test run ' included five influent and effluent samples that were averaged to determine the test run "event mean concentrations" (EMC) and resulting removal efficiencies for SSC and TSS. All tests were run with sediment pre-loaded to 50% of the sump volume. % Removal 7Percent Target Target EMC m /L Efficiency Test of Flow EMC Influent Effluent Run MTFR (cfs) m /L SSC TSS SSC TSS (SSC) TSS 1 25 0.18 50 43 20 2.7 0 94 100 2 25 0.18 100 103 49 6.2 0 94 100 3 25 0.18 200 216 114 7.8 10 96 91 4 50 0.35 50 55 33 11 6 80 82 5 50 0.35 100 107 52 28 14 74 73 6 50 0.35 200 232 98 50 29 78 70 7 75 0.53 50 47 25 23 11 52 56 8 75 0.53 100 105 57 37 26 65 54 9 75 0.53 200 192 126 81 41 58 67 10 100 0.71 50 62 37 28 15 55 59 11 100 0.71 100 123 67 58 33 53 51 12 100 0.71 200 196 ill 107 54 45 51 13 125 0.88 50 39 16 21 13 44 19 14 125 0.88 100 112 50 66 36 41 28 ' 15 125 0.88 200 190 104 99 58 48 44 Note: All TSS samples analyzed by external state-certified laboratory. The results from all SSC and TSS test runs with the sump volume greater than 50% full are shown in Table 2. Target flow rates ranged from 25% of the MTFR (0.18 cfs) to 125% of the MTFR (0.88 cfs) and target influent EMC concentrations ranged from 50 mg/L to 200 mg/L. Consistent with flow-based separation systems, the results indicate that system performance was dependent on flow rate, with higher removal efficiencies achieved at lower flow rates. In general, the discrete removal efficiencies for the 15 test runs remained positive for flow rates up to 125% of the MTFR, at which point bypass would be occurring. This demonstrates better control over the tested loading rates than conventional gravity-based separators with internal bypass. ©2011 Hydro International Performance Evaluation— First Defense® Page 7 of 8 r Hydrol, International storm water ' All samples were included in calculating the removal rates, as there were no observed outliers. Minimal variation was measured between the SSC target influent concentration and the o measured SSC concentrations. Measured influent TSS concentrations were approximately 50% lower than the target EMC. However, lower TSS measurements are expected for particles having high settling velocities due to the TSS analytical method, and both the TSS influent and effluent measurements were consistent with this trend. As a result, the variation of TSS influent concentration relative to the target EMC did not have a significant effect on removal efficiencies. The annual system performance was calculated using the NJDEP method for weighting removal efficiency data. The results in Table 3 show that the First Defense will achieve approximately ' 70% removal of SSC/TSS based on the NJDEP weighted removal efficiency calculation. Target NJDEP Average Removal Weighted Removal Flow Weight Efficienc Efficiency % MTFR (cfs) Factor SSC TSS SSC TSS 25 0.18 0.25 95% 94% 24% 23% 50 0.35 0.30 77% 79% 23% 24% 75 0.53 0.20 58% 63% 12% 13% 100 0.71 0.15 51% 47% 8% 7% 125 0.88 0.10 1 44% 32% 4% 3% Treatment Efficiency = 71% 70% Washout Testing Conclusions The washout test results showed no measurable washout from the First Defense when 50% of the sump was pre-loaded with OK-110 at flow rates of 125% and 200% of the MTFR. Additionally, washout test results showed sediment retention greater than 90% of the pre-loaded sediment for both 125% and 200% of the MTFR. Washout testing results also met the NJDEP protocol requirement of less than 10 mg/L effluent ' concentration for both 125% and 200% of the MTFR. In conclusion, the First Defense met or exceeded the test requirements to show no measurable effluent TSS or SSC levels. This implies that a larger MTFR or a shallower sump is possible. Alternatively, it is reasonable to expect that finer particle sizes with lower settling velocities are likely to be retained and not washed out at the tested flow rates. Removal Efficiency Testing Conclusions Removal efficiency results from 15 test runs, operating within a flow range of 0.18 — 0.88 cfs showed good correlation between flow rate and removal efficiency for both SSC and TSS. In general, removal efficiencies were independent of the inlet concentrations, which ranged from 50 to 200 mg/L. The NJDEP weighted TSS/SSC removal efficiency calculation showed that overall performance was 70% for the First Defense with sediment pre-loaded in the sump to reduce the sump volume by 50%. ,' ©2011 Hydro International Performance Evaluation— First Defense® Page 8 of 8