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HomeMy WebLinkAbout24IWC9 - 2268-2284 Rte 32 Complete Stormwater Report 9-25-24 Stormwater Management Report Horizon View 2268-2284 Route 32 Montville CT 06353 Prepared for: Honeycomb Real Estate Partners 20 Avon Meadow Lane Avon, CT 06001 Prepared by: R.J. O’Connell & Associates, Inc. 80 Montvale Ave, Suite 201 Stoneham, MA 02180 Date: September 25, 2024 Page 1 Table of Contents I. Stormwater Report Narrative 1.0 Introduction ................................................................................................................... 3 2.0 Site Location and Description ....................................................................................... 3 3.0 Proposed Project ........................................................................................................... 3 4.0 Soil Data........................................................................................................................ 4 5.0 Hydrologic Methodology .............................................................................................. 4 6.0 Existing Drainage Conditions ....................................................................................... 5 6.1 On-Site Resources ................................................................................................... 5 6.2 Existing Hydrology ................................................................................................. 5 6.3 Pre-Development Hydrological Conditions ............................................................ 6 7.0 Proposed Drainage Conditions ..................................................................................... 6 7.1 Proposed Hydrology ............................................................................................... 6 Compliance with CT Stormater Manual Standards 7.2 Post-Development Hydrological Conditions .......................................................... 7 7.3 Catch Basin Grate Capacity Analysis ..................................................................... 8 7.4 Pipe Capacity Analysis ........................................................................................... 8 7.5 Groundwater Recharge ........................................................................................... 8 7.6 Stormwater Quality ................................................................................................. 8 7.7 Stormwater Calculations ....................................................................................... 10 8.0 Summary ..................................................................................................................... 13 Page 2 II. Figures Figure 1 – USGS Map Figure 2 – FEMA Flood Insurance Rate Map Figure 3 – NRCS Web Soil Survey Map Figure 4 – Off-Site Upstream Watershed Figure 5 – Existing Watershed Plan Figure 6 – Proposed Watershed Plan Figure 7 – Proposed Sub-catchment Plan III. Appendices Appendix A – Computations Pre-Development Hydrological Computations Post-Development Hydrological Computations Pipe/Inlet Capacity Analysis Level Spreader Swale Calculations Appendix B – Soil Report by NRCS Geotechnical Report by Whitestone Associates Inc Appendix C – Stormwater Pollution Control Plan (SWPCP) Appendix D – Operation and Maintenance Plan (O&M Plan) I. STORMWATER REPORT NARRATIVE Page 3 1.0 Introduction R.J. O’Connell & Associates, Inc. (RJOC) has prepared this Stormwater Management report on behalf of Steve Caprio of Honey Comb Real Estate Partners – 20 Avon Meadow Lane, Avon CT, for the proposed site improvements at 2268-2284 Route 32 located in Montville, Connecticut (refer to Figure 1, “USGS Map”). This study uses the computer program HydroCAD, version 10.10, to model existing and proposed hydrologic site conditions based on the Natural Resources Conservation Service (NRCS) TR-20 Computer Program for Project Formulation Hydrology. The study presents a comparative analysis of pre-development hydrologic conditions to post- development hydrologic conditions and demonstrates that the proposed condition will be an improvement over the existing stormwater management condition. 2.0 Site Location and Description The project site is a 3.4-acre parcel comprised entirely of open space located across from Fort Shantok Road in Montville, Connecticut. Existing conditions have been hydrologically analyzed for stormwater runoff generation. Currently there are two (2) existing sub-catchments; EX-1 & EX-OS1 refer to Figure 5 Existing Watershed Plan for details. Sub-catchment EX-1 is an open space area that discharges at the southwestern portion of the site onto Meadow Lane Road. EX- OS1 is the tributary off site areas that flows onto the property and also discharges at the Southwestern portion of the site onto Meadow Lane. 3.0 Proposed Project The proposed project consists of constructing a new 4 story, 60,000± square foot residential building with 57 units, parking, landscaping and appurtenances. Stormwater runoff collected from the roof will be conveyed through the main on-site stormwater system. Runoff from paved areas will be collected within 4-foot-deep sump catch basins, hydro dynamic particle separator, and sub-surface infiltration system, surface wet/detention pond prior to discharge offsite to Meadow Lane. The tributary up-stream offsite area stormwater runoff will be diverted to a proposed detention basin prior to discharge to the Meadow Lane. Hydrologic analysis was performed for the proposed conditions for the 2-year, 10-year, 25-year, and 100-year, 24-hour storm events. The site has been divided into three (3) sub-catchments, PR1-1, PR1-2, & PR-OS1. Sub-catchments PR1-1 and PR1-2 are the onsite areas located on the project parcel. Sub-catchment PR-OS-1 is the offsite upstream residential area that flows onto our site. Sub-catchment PR-1 is comprised of the proposed building, parking and accessway, and landscaped areas. Runoff from sub-catchment PR1-1 will be collected in deep sump catch basins with hoods and pre-treated within a hydro-dynamic particle separator before being directed to the proposed subsurface infiltration system and wet/detention basin prior to discharge to Meadow Lane. PR1-2 is the southern landscaped perimeter of site and shall sheet flow off the site to Meadow Lane. The PR-OS1 stormwater runoff shall be diverted to a proposed detention basin on site prior to discharge to Meadow Lane. The on-site stormwater management system has been designed to capture, detain, and treat stormwater runoff from the on-stormwater runoff while capturing and detaining stormwater runoff from the offsite tributary area, which will improve runoff conditions. The proposed stormwater system will comply with the CT Stormwater Management Standards as described Page 4 herein. Runoff control and water quality improvements will be accomplished by implementing the following practices: • Implement a Stormwater Pollution Prevention Plan (SWPPP) to control erosion sedimentation and other construction related impacts; • Install a sub-surface infiltration system to retain and recharge the water quality volume • Install detention/wet basins for peak flow mitigation • Collect storm runoff in catch basins with deep sumps and hooded outlets; • Install drainage manholes and a hydrodynamic particle separator • Implement an Operation and Maintenance Plan (O&M) for the proposed stormwater management system that describes the various components of the system, identifies inspection and maintenance tasks, and provides a schedule to follow, which will ensure the proper long-term performance of the system; The proposed stormwater management measures described above will result in an improvement to the overall stormwater management condition. Stormwater runoff will be reduced, and water quality enhanced, thereby providing and improvement compared to the existing conditions. 4.0 Soil Data Soil data was compiled using the Natural Resources Conservation Service (NRCS Web Soil Survey) located at URL: websoilsurvey.sc.egov.usda.gov/App/HomePage.htm. The soil survey identified the majority of the site to be 29B-Agawam fine sandy loam. Hydrologic soil group B has been identified in the NRCS Soils classification but further exploration will has been completed to ascertain the Hydologic Soils as per the CT Stormwater Manual. On July 23 and August 10, 2024 Whitestone Associates, Inc performed test pits and boring to ascertain the soils data. As per the CT Stormwater Manual, the soil classification given was a Rawls rate of 1.02 via soil classification for A soils. Refer to Figure 3 Soils map and Appendix A for Geotechnical report. 5.0 Hydrologic Methodology Pre- and post-development drainage analyses were performed for the 2, 10, 25 and 100-year storm events. Rainfall events have been compiled by NOAA Atlas for extreme precipitation for the region as noted below: County 2-year 10-year 25-year 100-year New London 3.46 in. 5.12 in. 6.16 in. 7.76 in. The NRCS method uses several parameters based on watershed characteristics and configuration to generate a curvilinear unit hydrograph and produce a runoff hydrograph for the watershed. Basic input data required to generate a hydrograph are the watershed area, storm frequency, time of concentration, 24-hour rainfall, and the watershed’s runoff curve number. Page 5 NRCS Technical Release 55 (TR-55) methodology was utilized to determine weighted runoff curve number (CN) for the pre- and post-development watershed areas. Inputs for obtaining the weighted CN were determined based on ground cover type and the Hydrological Soil Group (HSG), as described in the Soil Data section above. Time of concentration (Tc) was determined based on the most hydrologically distant point (time-wise) within the watershed. Watershed boundaries were established based on topography, storm drainage layouts, and the location of major drainage discharge points, or Point of Analysis (POA). An off-site watershed plan is attached to depict the offsite residential area tributary to the project parcel. The pre- development watershed boundaries can be seen in Figure 5, “Existing Watershed Plan.” The post-development boundaries can be seen on Figure 6, “Proposed Watershed Plan”. 6.0 Existing Drainage Conditions 6.1 On-Site Resources The site lies within flood Zone X per FEMA FIRM Map Number 09011C0351G effective date July 18, 2011. Though the proposed construction area lies outside of the flood zone. 6.2 Existing Hydrology The existing site has been analyzed under current extreme precipitation values for the 2-year, 10-year, 25-year, and 100-year 24-hour storm events. The Point of Analysis (POA-1) has been identified as the southwestern portion of the site at Meadow Lane. The existing stormwater runoff from both on and off-site discharge to the Point of Analysis (POA-1). Existing Sub-Catchment Area 1 (EX-1) This 3.58-acre sub-catchment area consists of the entire open space area on the proposed development parcel and overland flow to the rear tributary to the site. Stormwater sheet flows over the open space area and form shallow concentrated flow to the Point of Analysis (POA-1) Existing Sub-Catchment Area 1 (EX-OS1) This 16-acre sub-catchment area consists of the upstream area tributary to the proposed project site. The upstream residential area is a residential subdivision consisting of a portion of Ridge Drive, Walnut Drive, and Cedar Lane. Stormwater is collected by 3 catch basins and discharge via a 15” culvert an open space area prior to reaching the project parcel. Stormwater Runoff flows thru a ditch and silt filled wetland area. Stormwater runoff sheet flows over the open space area and from shallow concentrated flow to the Point of Analysis (POA-1). See Figure 4 Off-site Upstream Watershed Plan for additional information. Page 6 6.3 Pre-Development Hydrological Conditions Below is a summary of the pre-development hydrological conditions at the Point of analysis Pre-Development Peak Rates of Runoff in Cubic Feet per Second (cfs) Location 24-Hour Storm Events 1-year 2-year 10-year 25-year 100-year POA-1 0.59 1.47 7.53 13.08 23.12 Comprehensive hydrological computations for pre-development conditions are included in Appendix B. 7.0 Proposed Drainage Conditions 7.1 Application of Stormwater Management Standards and Performance Criteria The proposed development project is made up of three (3) sub-catchment areas for analysis (see Figure 5 – “Proposed Watershed Plan”). Stormwater runoff generated over paved areas will be captured by a deep sump catch basin with hooded outlets and routed through a hydrodynamic particle separator and a subsurface infiltration system prior to discharge to POA-1. Proposed Sub-Catchment Area 1 (PR1-1) This 3.4-acre sub-catchment area consists of the proposed residential building, parking area, access drive, associated landscaping and appurtenances. Stormwater runoff collected over the roof will be collected by roof drains flow to the proposed stormwater system. Stormwater runoff from paved surfaces will be collected in deep sump catch basins with hooded outlets, hydrodynamic particle separator, and subsurface infiltration system and detention basin prior to discharge to Meadow Lane POA-1. Proposed Sub-Catchment Area 2 (PR1-2) This 0.18-acre sub-catchment area consists of the southern perimeter of the site. The sub- catchment is entirely open space and runoff sheet off the site to the south to Meadow Lane POA- 1. Proposed Sub-Catchment Area 3 (PR-OS1) This 16-acre sub-catchment area consists of the upstream area tributary to the proposed project site. Stormwater runoff sheet is collected by a depression at the northern proposed head wall and is piped to a proposed wet basin. The wet basin discharges to the southwestern portion of the site to Meadow Lane at POA-1. Page 7 7.2 Post-Development Hydrological Conditions For the on-site stormwater management program, under proposed developed conditions, deep- sump catch basins with hooded outlets, hydrodynamic particle separator, subsurface infiltration, and detention basin will treat stormwater runoff before it is discharged off-site at Meadow Lane POA-1. The off-site stormwater management program consists of a wet basin to divert and mitigate peak flows prior to discharge to Meadow Lane POA-1. Below is a comparison summary table of the pre- and post-development peak rates of runoff at the point of analysis. The peak rates of stormwater discharged from the site for the storm events analyzed will be reduced under proposed conditions as compared to existing conditions. Pre- and Post-Development Peak Rates of Runoff in Cubic Feet per Second (cfs) Point of Analysis 1 Storm Frequency Existing Flow Rate (cfs) Proposed Flow Rate (cfs) Change (cfs) % Reduction 1-Year 0.59 0.31 -0.28 47% 2-Year 1.47 1.17 -0.30 20% 10-Year 7.53 7.23 -0.30 4% 25-Year 13.08 12.05 -1.03 8% 100-Year 23.12 16.46 -6.66 29% Pre- and Post-Development Volume of Runoff in Acre-Feet (af) Point of Analysis 1 Storm Frequency Existing Volume (ac-ft) Proposed Volume (ac-ft) Change (ac-ft) % Reduction 1-Year 0.268 0.180 -0.088 33% 2-Year 0.570 0.379 -0.148 28% 10-Year 1.659 1.412 -0.247 15% 25-Year 2.576 2.358 -0.218 8% 100-Year 4.206 4.001 -0.205 5% Page 8 Comprehensive hydrological computations for post-development conditions are included in Appendix A. 7.3 Catch Basin Grate Capacity Analysis Grate capacity calculations have been performed for the proposed inlet structures for the 25-year storm event. Refer to Appendix A for calculations. 7.4 Pipe Capacity and Level Spreader Analysis Pipe capacity calculations have been performed for the proposed inlet structures for the 10-year storm event. Level spreader calculations have been performed for the 100-yr storm event. Refer to Appendix A for calculations. 7.5 Groundwater Recharge As the site is comprised of Sandy Loam with a Hydrologic Soil Group A. See Section 7.7 below for calculations. 7.6 Stormwater Quality The development program includes suitable Best Management Practices (BMPs) to pre-treat runoff from paved parking lot areas prior to infiltration. Stormwater quality will be improved through the use of the following BMPs to remove 80% of TSS overall prior to discharge off-site. See below for TSS removal calculations. • Catch Basins with Deep Sumps and Hooded Outlets Stormwater runoff from pavement areas will be directed via curbing and site grading to catch basins with deep sumps and hooded outlets. Catch basins trap and remove sediments and larger particles from stormwater runoff and improve the performance of subsequent BMP’s. The catch basin sumps will be a minimum of 4 feet in depth, and a regular inspection and cleaning schedule will be followed to ensure optimal effectiveness. When properly constructed and maintained, catch basins with deep sumps and hooded outlets are effective in reducing the sediment and pollutant load in runoff. • Hydrodynamic Particle Separators The hydrodynamic particle separator is a precast concrete structure that uses a helical flow pattern that enhances trapping and containment of pollutants and provides effective removal of settleable solids and floating contaminants from stormwater runoff. Low storm flows are directed into a tangentially oriented downward pipe that induces a swirling motion in the treatment chamber that increases capture and containment abilities. Moderate storm flows are directed into the treatment chamber through a secondary inlet, which allows for capture of floating trash and debris. The secondary inlet also provides treatment of higher flows without significantly increasing the velocity or turbulence in the treatment chamber. This allows for a separation environment. Settleable solids and pollutants are captured and contained in the treatment chamber. Flow exits the treatment Page 9 chamber through the outlet flow control, which manages the amount of flow that is treated and helps maintain the helical flow patterns developed within the treatment chamber. Flows exceeding the system’s rated treatment flows are diverted away from the treatment chamber by the flow partition. Internal diversion of high flows eliminates the need for external by-pass structures. During by-pass, the head equalizing baffle applies head on the outlet flow control to limit the flow through the treatment chamber. This helps prevent the re-suspension of previously captured pollutants. Stormwater will be routed through the hydrodynamic separators prior to discharging into the surface infiltration system. • Subsurface Infiltration System The subsurface infiltration system is similar to a subsurface detention system although they have a perforated pipes set in crushed stone to promote infiltration into the groundwater Four (4) feet of separation from groundwater is required to install a subsurface infiltration system. The infiltration chambers are sized to store the recharge volume below the lowest outlet invert to retain and promote the infiltration of the recharge volume. • Detention Basin Detention Basins are designed to capture, temporarily hold, and gradually release a volume of stormwater runoff to attenuate and delay stormwater runoff peaks. Detention Basins are typically designed as on-line systems and provide stormwater quality control but only limited water quality benefits. The primary outlet of a detention basin is located at the bottom of the basin and is sized to limit the max flow rate from the basin for the water quality storm. The higher stages of the basin attenuate the peak rates of runoff from larger storm events. Detention Basins are designed to completely empty between storms, typically in 24 to 48 hours, resulting in limited settling of particulate matter and the potential for re-suspension of sediment by subsequent runoff events. Page 10 7.7 Stormwater Calculations 1. Water Quality Volume (PR-1): 𝑉𝑃𝑉=(𝑃)∗(𝑃)∗(𝐴)(1𝑒𝑞 12�ℎ𝑚) Where: WQV = Water Quality Volume R = Volumetric Runoff Coefficient (dimensionless) = 0.05+0.009(I) I = Percent Impervious Cover = 90,735 SF / 148,322 SF = 62 % A= Drainage Area in Acres = 148,322 SF 𝑃=0.05 +0.009(𝐼) 𝑃=0.05 +0.009(62) 𝑃=0.608 𝑉𝑃𝑉=1.30 ∗0.608 ∗148,322 (1𝑒𝑞 12�ℎ𝑚) 𝑉𝑃𝑉=9,770 𝐶𝐹=0.224 𝑎𝑐𝑞𝑒 𝑒𝑒𝑒𝑞 Proposed Volume provided 21,085 CF 2. Water Quality Flow (PR-1): 𝑉𝑃𝐹=𝑞𝑢∗𝐴𝑠𝑚∗𝑃 Where: WQF = Water Quality Flow (cfs) qu = Volumetric Runoff Coefficient from Exhibit 4-11 in Chp. 4 of TR-55 (csm/inch) Asm = Drainage Area in square miles = 3.41 acres * (1 sq. mi. / 640 acres) = 0.0053 acres Q = Runoff Depth (inches) a.) Compute the Runoff Depth (Q): 𝑃= 𝑉𝑃𝑉∗(12 𝐼𝑚𝑐�𝑒𝑞/𝑒𝑚𝑚𝑞) 𝐴 𝑃=0.224 𝑎𝑐𝑞𝑒−𝑒𝑒𝑒𝑞∗(12 �ℎ𝑚𝑐�𝑒𝑞/𝑒𝑚𝑚𝑞) 3.41 𝑎𝑐𝑞𝑒𝑞 𝑃=0.79 �ℎ𝑚𝑐�𝑒𝑞 Page 11 b.) Read Unit Peak Discharge, qu, from Exhibit 4-11 in Chp 4 of TR-55: Where: Tc = Time of Concentration in Hours: 6 minutes * (1 hour / 60 minutes) = 0.1 hours qu = Unit Peak Discharge (csm/in): 330 csm/in c.) Compute the Water Quality Flow: 𝑉𝑃𝐹=𝑞𝑢∗𝐴𝑠𝑚∗𝑃 𝑉𝑃𝐹=330 𝑐𝑞𝑚/�ℎ𝑚∗0.0053 𝑞𝑞.𝑚�ℎ.∗0.61 �ℎ𝑚𝑐�𝑒𝑞 𝑉𝑃𝐹=1.06 𝑐𝑒𝑞 Page 12 3. Groundwater Recharge Volume As the site has HSG A soils on site with a design infiltration volume 100% of the Water quality/Retention Volume plus additional runoff volume to attenuate peak runoff rates associated with the 2-year, 10-year, and 100-year storm. The required recharge volume is 9,770 cf. Total Recharge Volume Provided: The proposed infiltration system is designed to retain and infiltrate the water quality volume. Storm events greater than 1-inch shall be conveyed through the subsurface infiltration basin to the proposed detention basin then to Meadow Lane The total recharge volume provided is: Stormwater BMP Elevation Groundwater Elevation Recharge Volume (cf) Infiltration Basin 142.0 – 146.0 138.0 21,085 Total Volume Provided 21,085 Total Drain Time Td = (V/K x A) x 12 inches/foot Td = Drain time Hours V = Design Infiltration Volume or static storage volume = 21,085 cf K = Design infiltration rate (inches per hour) = 1.02 inches per hour A = Average surface area of infiltration system = 49 x 155 = 7,595 Td = (21,085/1.02 x 7,595) x 12 inches/foot Td = 33 hours 4. Static Storage/retention Volume The proposed static storage/retention volume is included in the stage storage table. The storage volume on-site is the volume of water stored in the proposed subsurface infiltration system below the low flow orifice. The total storage volume is 21,085 cf and can be found in appendix A Proposed HydroCAD Stage Storage Tables. 5. Stream Channel Protection (Not Applicable) 6. Conveyance Protection (Not Applicable) The proposed drainage conveyance system has been sized for the 25-year, 24-hour post development peak flow. Refer to Appendix A for the Pipe and Grate Capacity Analysis for additional information. Page 13 7. Peak Runoff Attenuation (DAA-1) Storm Event Pre-Development Flow (cfs) Post-Development Flow (cfs) Delta (cfs) 1-year, 24-hour 0.59 0.29 0.30 2-year, 24-hour 1.47 1.00 0.47 10-year, 24-hour 7.53 6.99 0.54 25-year, 24-hour 13.08 11.41 1.67 100-year, 24-hour 23.12 16.35 6.77 8. Emergency Outlet Sizing (PR-1) The proposed detention stormwater basin includes an emergency spillway but the peak elevation of the 100-year storm event is below the emergency spillway elevation. 9. Erosion Control/Scour Protection Erosion control or scour protection will be placed at all pipe and flume locations where erosion or scour may occur. 8.0 Summary This hydrologic analysis estimates peak storm runoff discharged from the site under both the existing and proposed conditions. The stormwater management system for the proposed development includes measures for collecting, controlling, and treating stormwater runoff from the site. The proposed measures comply with the stormwater management standards of the CT Stormwater Manual and represent an improvement over the existing conditions. The drainage improvements proposed herein will reduce stormwater runoff peak flow rates leaving the site and improve the overall water quality of stormwater runoff. An Operation and Maintenance Manual has been included as part of this report to ensure the long-term operation of the proposed stormwater management system. As part of the proposed Operation and Maintenance Manual, a Long-Term Pollution Prevention Plan (LTPPP) has been incorporated to ensure proper spill prevention and management materials area available on site and staff are properly trained to prevent additional pollutant loading. II. FIGURES Copyright © 2021 by R.J. O'Connell & Associates, Inc. RJO'CONNELL & ASSOCIATES, INC. CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS FIGURE 1 USGS MAP SCALE:DATE:07/18/2024 1"=1,000' 0 GRAPHIC SCALE IN FEET 1,000 500 1,000 2,000 N MONTVILLE, CT MONTVILLE, CTDrawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Reports\Stormwater Report\Figures\Figure 2 FEMA Flood Map.dwg Jul 18, 2024 - 13:27pm Copyright © 2023 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERSFIGURE 2FEMA FLOOD INSURANCE RATE MAPSCALE:DATE:07/18/20241"=300'0GRAPHIC SCALE IN FEET300150300600NSITE MONTVILLE, CTDrawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Reports\Stormwater Report\Figures\Figure 3 Soils Map.dwg Sep 23, 2024 - 13:10pm Copyright © 2023 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERSFIGURE 3NRCS SOILS MAPSSCALE:DATE:09/25/20241"=200'0GRAPHIC SCALE IN FEET200100200400NSITENRCS SOIL MAP LEGENDMAP UNITSYMBOLMAP UNIT NAMEHSG29BAGAWAM FINE SANDY LOAM3 TO 8 PERCENT SLOPESB62DCANTO AND CHARLTON FINESANDY LOAMS15 TO 35 PERCENT SLOPESEXTREMELY STONEYB73ECHARLTON-CHATFIELDCOMPLEX15 TO 45 PERCENT SLOPEB34BMERRIMAC FINE SANDY LOAM3 TO 8 PERCENT SLOPESA © 2024 Microsoft Corporation © 2024 Maxar ©CNES (2024) Distribution Airbus DS EX-OS1 TOTAL AREA = 17.070 ACRES CN = 53 Tc = 30 MINUTES SITE N 0 GRAPHIC SCALE IN FEET 250 125 250 500 ROUTE 32CEDAR LNRIDGE DRWALNUT DR WEBB DRCRESTV I E W D R BRO A D V I E W A V E RICHARD BROWN DR EX-OS1 TOTAL AREA = 17.070 ACRES CN = 53 Tc = 30 MINUTES 3 CATCH BASINS ON CEDAR LANE SEE PHOTO 1 & 2 EXISTING CULVERT SEE PHOTO 3 & 4 ACCUMULATED SEDIMENT IN WETLAND AT NORTH PROPERTY LINE SEE PHOTO 5 & 6 SITE N 0 GRAPHIC SCALE IN FEET 250 125 250 500 ROUTE 32CEDAR LNRIDGE DRWALNUT DR WEBB DRCRESTV I E W D R BRO A D V I E W A V E RICHARD BROWN DR OFF-SITE WATERSHED Photo #1Photo #2Photo #3Photo #4Catch basin on Cedar LaneCatch basins on Cedar laneCulvert from Catch bason from Cedar LaneCulvert from Catch bason from Cedar Lane Photo #5Photo #6Downstream Cedar Lane Culvert accumulated sediment  in Wetland at the northern property line.Downstream Cedar Lane Culvert accumulated sediment  in Wetland at the northern property line.Photo #7 Photo #8CMP pipeCMP pipe Copyright © 2022 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERSFIGURE 4EXISTING WATERSHED PLANSCALE:1"=50'0GRAPHIC SCALE IN FEET502550100N40 TUNXIS AVENUEBLOOMFIELD, CT 06002DATE:9/25/2024WATERSHED BOUNDARYLEGENDBUILDINGOPEN SPACE-GRASS/WOODSOPEN SPACE-WOODS/BRUSHPOINT OF ANALYSISPAVEMENT/IMPERVIOUSTc PATHwPOA-1 MM M VVVVVVT VANVANPR1-1 TOTAL AREA = 129,673 SF TOTAL IMP. = 90,734 SF CN = 87 Tc = 6.0 MINUTES PR1-2 TOTAL AREA = 13,857 SF TOTAL IMP. = 0 SF CN = 61 Tc = 6.0 MINUTES PR-OS-1 TOTAL AREA = 719,741 SF TOTAL AREA = 16 ACRE + 1046 + 18,705 SF CN = 53 Tc = 30.0 MINUTES (OFF-SITE) Tc = 1.3 MINUTES (ON-SITE) Tc = 31.3 MINUTES (COMBINED)wwwwwwPOA-1 (WITH COMMON LEVEL SPREADER) Q2 = 1.17 CFS Q10 = 7.23 CFS Q25 = 12.05 CFS Q100 = 16.46 CFSwwwwwwwwwwSUBSURFACE INFILTRATION SYSTEM Drawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Engineer\Drainage\Watershed\Proposed Watershed Plan.dwg Sep 23, 2024 - 13:17pmCopyright © 2022 by R.J. O'Connell & Associates, Inc. RJO'CONNELL & ASSOCIATES, INC. CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS FIGURE 6 PROPOSED WATERSHED PLAN SCALE:1"=60'0 GRAPHIC SCALE IN FEET 50 25 50 100 N WATERSHED BOUNDARY LEGEND BUILDING OPEN SPACE-GRASS/WOODS OPEN SPACE-WOODS/BRUSH DESIGN ANALYSIS AREA PAVEMENT/IMPERVIOUS Tc PATHww POA-1 DATE:09/25/2024 2268-2284 ROUTE 32 MONTVILLE, CT MM M VVVVVVT VANVANDAA-OS Q2 = 0.35 CFS Q10 = 2.69 CFS Q25 = 5.22 CFS Q100 = 8.48 CFS PR1-1 TOTAL AREA = 147,378 SF TOTAL IMP. = 90,734 SF CN = 87 Tc = 6.0 MINUTES PR1-2 TOTAL AREA = 13,857 SF TOTAL IMP. = 0 SF CN = 61 Tc = 6.0 MINUTES PR-OS-1 TOTAL AREA = 393,086 SF TOTAL AREA = 9 ACRE + 1046 SF CN = 53 Tc = 31.3 MINUTES wwwwwwDAA-1 Q2 = 0.07 CFS Q10 = 0.23 CFS Q25 = 0.65 CFS Q100 = 2.72 CFSwwwwwwwwwwSC-1 TOTAL AREA = 6,518 SF TOTAL IMP. = 5,913 SF CN = XX Tc = X.X MINUTES SC-2 TOTAL AREA = 13,942 SF TOTAL IMP. = 8,387 SF CN = XX Tc = X.X MINUTES SC-3 TOTAL AREA = 19,132 SF TOTAL IMP. = 13,793 SF CN = XX Tc = X.X MINUTES SC-4 TOTAL AREA = 8,894 SF TOTAL IMP. = 8,257 SF CN = XX Tc = X.X MINUTES SC-5 TOTAL AREA = 26,978 SF TOTAL IMP. = 22,384 SF CN = XX Tc = X.X MINUTES SC-6 TOTAL AREA = 7,719 SF TOTAL IMP. = 5,879 SF CN = XX Tc = X.X MINUTES SC-7 TOTAL AREA = 16,237 SF TOTAL IMP. = 11,870 SF CN = XX Tc = X.X MINUTES Drawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Engineer\Drainage\Watershed\Proposed Catchment Plan.dwg Sep 23, 2024 - 13:32pmCopyright © 2022 by R.J. O'Connell & Associates, Inc. RJO'CONNELL & ASSOCIATES, INC. CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS FIGURE 7 PROPOSED CATCHMENT PLAN SCALE:1"=60'0 GRAPHIC SCALE IN FEET 50 25 50 100NWATERSHED BOUNDARY LEGEND BUILDING OPEN SPACE-GRASS/WOODS OPEN SPACE-WOODS/BRUSH DESIGN ANALYSIS AREA PAVEMENT/IMPERVIOUS Tc PATHww MONTVILLE, CT DAA-1 DATE:09/25/2024 III. APPENDICIES APPENDIX A Computations Pre-Development Hydrological Computations EX-OS1 Off-Site Residential Area - 16 Acres EX1-1 Existing Site DAA-1 Galvin Lane Routing Diagram for Pre-DevelopmentPrepared by R J O'Connell & Associates Inc, Printed 9/19/2024 HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Subcat Reach Pond Link Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 2HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 3.587 61 >75% Grass cover, Good, HSG B (EX1-1) 16.070 53 OFF SITE RESIDENTIAL AREAS (EX-OS1) Type III 24-hr 2 Year Rainfall=3.46"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 3HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment EX-OS1: Off-Site Residential Area - 16 Acres Runoff = 1.09 cfs @ 12.92 hrs, Volume= 0.361 af, Depth= 0.27" Routed to Link DAA-1 : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 2 Year Rainfall=3.46" Area (ac) CN Description * 16.070 53 OFF SITE RESIDENTIAL AREAS 16.070 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, 10.3 100 0.0400 0.16 Sheet Flow, Grass: Dense n= 0.240 P2= 3.50" 3.9 287 0.0300 1.21 Shallow Concentrated Flow, ON SITE SHALLOW CONC. FLOW Short Grass Pasture Kv= 7.0 fps 44.2 387 Total Subcatchment EX-OS1: Off-Site Residential Area - 16 Acres Runoff Hydrograph Time (hours)3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 2 Year Rainfall=3.46" Runoff Area=16.070 ac Runoff Volume=0.361 af Runoff Depth=0.27" Flow Length=387' Tc=44.2 min CN=53 1.09 cfs Type III 24-hr 2 Year Rainfall=3.46"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 4HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment EX1-1: Existing Site Runoff = 1.32 cfs @ 12.22 hrs, Volume= 0.166 af, Depth= 0.55" Routed to Link DAA-1 : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 2 Year Rainfall=3.46" Area (sf) CN Description 156,264 61 >75% Grass cover, Good, HSG B 156,264 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.3 100 0.0400 0.16 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.50" 0.2 76 0.1300 5.80 Shallow Concentrated Flow, Shallow Flow through site to Galvin Unpaved Kv= 16.1 fps 1.9 316 0.0300 2.79 Shallow Concentrated Flow, Shallow Concentrated Flow on site Unpaved Kv= 16.1 fps 12.4 492 Total Subcatchment EX1-1: Existing Site Runoff Hydrograph Time (hours)3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 2 Year Rainfall=3.46" Runoff Area=156,264 sf Runoff Volume=0.166 af Runoff Depth=0.55" Flow Length=492' Tc=12.4 min CN=61 1.32 cfs Type III 24-hr 2 Year Rainfall=3.46"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 5HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Link DAA-1: Galvin Lane Inflow Area = 19.657 ac, 0.00% Impervious, Inflow Depth = 0.32" for 2 Year event Inflow = 1.47 cfs @ 12.86 hrs, Volume= 0.527 af Primary = 1.47 cfs @ 12.86 hrs, Volume= 0.527 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Link DAA-1: Galvin Lane Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=19.657 ac 1.47 cfs1.47 cfs Type III 24-hr 10 Year Rainfall=5.12"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 6HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment EX-OS1: Off-Site Residential Area - 16 Acres Runoff = 6.30 cfs @ 12.73 hrs, Volume= 1.228 af, Depth= 0.92" Routed to Link DAA-1 : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 10 Year Rainfall=5.12" Area (ac) CN Description * 16.070 53 OFF SITE RESIDENTIAL AREAS 16.070 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, 10.3 100 0.0400 0.16 Sheet Flow, Grass: Dense n= 0.240 P2= 3.50" 3.9 287 0.0300 1.21 Shallow Concentrated Flow, ON SITE SHALLOW CONC. FLOW Short Grass Pasture Kv= 7.0 fps 44.2 387 Total Subcatchment EX-OS1: Off-Site Residential Area - 16 Acres Runoff Hydrograph Time (hours)3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Type III 24-hr 10 Year Rainfall=5.12" Runoff Area=16.070 ac Runoff Volume=1.228 af Runoff Depth=0.92" Flow Length=387' Tc=44.2 min CN=53 6.30 cfs Type III 24-hr 10 Year Rainfall=5.12"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 7HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment EX1-1: Existing Site Runoff = 4.47 cfs @ 12.19 hrs, Volume= 0.431 af, Depth= 1.44" Routed to Link DAA-1 : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 10 Year Rainfall=5.12" Area (sf) CN Description 156,264 61 >75% Grass cover, Good, HSG B 156,264 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.3 100 0.0400 0.16 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.50" 0.2 76 0.1300 5.80 Shallow Concentrated Flow, Shallow Flow through site to Galvin Unpaved Kv= 16.1 fps 1.9 316 0.0300 2.79 Shallow Concentrated Flow, Shallow Concentrated Flow on site Unpaved Kv= 16.1 fps 12.4 492 Total Subcatchment EX1-1: Existing Site Runoff Hydrograph Time (hours)3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)5 4 3 2 1 0 Type III 24-hr 10 Year Rainfall=5.12" Runoff Area=156,264 sf Runoff Volume=0.431 af Runoff Depth=1.44" Flow Length=492' Tc=12.4 min CN=61 4.47 cfs Type III 24-hr 10 Year Rainfall=5.12"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 8HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Link DAA-1: Galvin Lane Inflow Area = 19.657 ac, 0.00% Impervious, Inflow Depth = 1.01" for 10 Year event Inflow = 7.53 cfs @ 12.64 hrs, Volume= 1.659 af Primary = 7.53 cfs @ 12.64 hrs, Volume= 1.659 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Link DAA-1: Galvin Lane Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 Inflow Area=19.657 ac 7.53 cfs7.53 cfs Type III 24-hr 25 Year Rainfall=6.16"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 9HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment EX-OS1: Off-Site Residential Area - 16 Acres Runoff = 11.09 cfs @ 12.70 hrs, Volume= 1.944 af, Depth= 1.45" Routed to Link DAA-1 : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 25 Year Rainfall=6.16" Area (ac) CN Description * 16.070 53 OFF SITE RESIDENTIAL AREAS 16.070 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, 10.3 100 0.0400 0.16 Sheet Flow, Grass: Dense n= 0.240 P2= 3.50" 3.9 287 0.0300 1.21 Shallow Concentrated Flow, ON SITE SHALLOW CONC. FLOW Short Grass Pasture Kv= 7.0 fps 44.2 387 Total Subcatchment EX-OS1: Off-Site Residential Area - 16 Acres Runoff Hydrograph Time (hours)3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25 Year Rainfall=6.16" Runoff Area=16.070 ac Runoff Volume=1.944 af Runoff Depth=1.45" Flow Length=387' Tc=44.2 min CN=53 11.09 cfs Type III 24-hr 25 Year Rainfall=6.16"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 10HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment EX1-1: Existing Site Runoff = 6.86 cfs @ 12.18 hrs, Volume= 0.632 af, Depth= 2.11" Routed to Link DAA-1 : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 25 Year Rainfall=6.16" Area (sf) CN Description 156,264 61 >75% Grass cover, Good, HSG B 156,264 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.3 100 0.0400 0.16 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.50" 0.2 76 0.1300 5.80 Shallow Concentrated Flow, Shallow Flow through site to Galvin Unpaved Kv= 16.1 fps 1.9 316 0.0300 2.79 Shallow Concentrated Flow, Shallow Concentrated Flow on site Unpaved Kv= 16.1 fps 12.4 492 Total Subcatchment EX1-1: Existing Site Runoff Hydrograph Time (hours)3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)7 6 5 4 3 2 1 0 Type III 24-hr 25 Year Rainfall=6.16" Runoff Area=156,264 sf Runoff Volume=0.632 af Runoff Depth=2.11" Flow Length=492' Tc=12.4 min CN=61 6.86 cfs Type III 24-hr 25 Year Rainfall=6.16"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 11HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Link DAA-1: Galvin Lane Inflow Area = 19.657 ac, 0.00% Impervious, Inflow Depth = 1.57" for 25 Year event Inflow = 13.08 cfs @ 12.61 hrs, Volume= 2.576 af Primary = 13.08 cfs @ 12.61 hrs, Volume= 2.576 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Link DAA-1: Galvin Lane Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=19.657 ac 13.08 cfs13.08 cfs Type III 24-hr 100 Year Rainfall=7.76"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 12HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment EX-OS1: Off-Site Residential Area - 16 Acres Runoff = 19.87 cfs @ 12.65 hrs, Volume= 3.231 af, Depth= 2.41" Routed to Link DAA-1 : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 100 Year Rainfall=7.76" Area (ac) CN Description * 16.070 53 OFF SITE RESIDENTIAL AREAS 16.070 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, 10.3 100 0.0400 0.16 Sheet Flow, Grass: Dense n= 0.240 P2= 3.50" 3.9 287 0.0300 1.21 Shallow Concentrated Flow, ON SITE SHALLOW CONC. FLOW Short Grass Pasture Kv= 7.0 fps 44.2 387 Total Subcatchment EX-OS1: Off-Site Residential Area - 16 Acres Runoff Hydrograph Time (hours)3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 100 Year Rainfall=7.76" Runoff Area=16.070 ac Runoff Volume=3.231 af Runoff Depth=2.41" Flow Length=387' Tc=44.2 min CN=53 19.87 cfs Type III 24-hr 100 Year Rainfall=7.76"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 13HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment EX1-1: Existing Site Runoff = 10.92 cfs @ 12.18 hrs, Volume= 0.975 af, Depth= 3.26" Routed to Link DAA-1 : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 100 Year Rainfall=7.76" Area (sf) CN Description 156,264 61 >75% Grass cover, Good, HSG B 156,264 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.3 100 0.0400 0.16 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.50" 0.2 76 0.1300 5.80 Shallow Concentrated Flow, Shallow Flow through site to Galvin Unpaved Kv= 16.1 fps 1.9 316 0.0300 2.79 Shallow Concentrated Flow, Shallow Concentrated Flow on site Unpaved Kv= 16.1 fps 12.4 492 Total Subcatchment EX1-1: Existing Site Runoff Hydrograph Time (hours)3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 100 Year Rainfall=7.76" Runoff Area=156,264 sf Runoff Volume=0.975 af Runoff Depth=3.26" Flow Length=492' Tc=12.4 min CN=61 10.92 cfs Type III 24-hr 100 Year Rainfall=7.76"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 14HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Link DAA-1: Galvin Lane Inflow Area = 19.657 ac, 0.00% Impervious, Inflow Depth = 2.57" for 100 Year event Inflow = 23.15 cfs @ 12.58 hrs, Volume= 4.206 af Primary = 23.15 cfs @ 12.58 hrs, Volume= 4.206 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Link DAA-1: Galvin Lane Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=19.657 ac 23.15 cfs23.15 cfs Type III 24-hr 1 Year Rainfall=2.90"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 15HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment EX-OS1: Off-Site Residential Area - 16 Acres Runoff = 0.30 cfs @ 13.41 hrs, Volume= 0.170 af, Depth= 0.13" Routed to Link DAA-1 : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 1 Year Rainfall=2.90" Area (ac) CN Description * 16.070 53 OFF SITE RESIDENTIAL AREAS 16.070 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, 10.3 100 0.0400 0.16 Sheet Flow, Grass: Dense n= 0.240 P2= 3.50" 3.9 287 0.0300 1.21 Shallow Concentrated Flow, ON SITE SHALLOW CONC. FLOW Short Grass Pasture Kv= 7.0 fps 44.2 387 Total Subcatchment EX-OS1: Off-Site Residential Area - 16 Acres Runoff Hydrograph Time (hours)3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type III 24-hr 1 Year Rainfall=2.90" Runoff Area=16.070 ac Runoff Volume=0.170 af Runoff Depth=0.13" Flow Length=387' Tc=44.2 min CN=53 0.30 cfs Type III 24-hr 1 Year Rainfall=2.90"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 16HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Subcatchment EX1-1: Existing Site Runoff = 0.59 cfs @ 12.33 hrs, Volume= 0.098 af, Depth= 0.33" Routed to Link DAA-1 : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 1 Year Rainfall=2.90" Area (sf) CN Description 156,264 61 >75% Grass cover, Good, HSG B 156,264 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.3 100 0.0400 0.16 Sheet Flow, Sheet Flow Grass: Dense n= 0.240 P2= 3.50" 0.2 76 0.1300 5.80 Shallow Concentrated Flow, Shallow Flow through site to Galvin Unpaved Kv= 16.1 fps 1.9 316 0.0300 2.79 Shallow Concentrated Flow, Shallow Concentrated Flow on site Unpaved Kv= 16.1 fps 12.4 492 Total Subcatchment EX1-1: Existing Site Runoff Hydrograph Time (hours)3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 1 Year Rainfall=2.90" Runoff Area=156,264 sf Runoff Volume=0.098 af Runoff Depth=0.33" Flow Length=492' Tc=12.4 min CN=61 0.59 cfs Type III 24-hr 1 Year Rainfall=2.90"Pre-Development Printed 9/19/2024Prepared by R J O'Connell & Associates Inc Page 17HydroCAD® 10.20-5b s/n 04881 © 2023 HydroCAD Software Solutions LLC Summary for Link DAA-1: Galvin Lane Inflow Area = 19.657 ac, 0.00% Impervious, Inflow Depth = 0.16" for 1 Year event Inflow = 0.59 cfs @ 12.34 hrs, Volume= 0.268 af Primary = 0.59 cfs @ 12.34 hrs, Volume= 0.268 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Link DAA-1: Galvin Lane Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=19.657 ac 0.59 cfs0.59 cfs Post-Development Hydrologic Computations PR-OS1 Off-Site Residential Area - 16 Acres PR1-1 Project Site PR1-2 South and Rear Grassed Area 1P Surface/Subsurface DetentionOS 1P Offsite Basin POA-1A Galvin Lane Routing Diagram for Post-Development Prepared by {enter your company name here}, Printed 9/23/2024 HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Subcat Reach Pond Link Existing Conditions Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 2HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 1.300 69 50-75% Grass cover, Fair, HSG B (PR-OS1, PR1-1) 0.204 61 >75% Grass cover, Good, HSG B (PR-OS1, PR1-2) 16.070 53 OFF SITE RESIDENTIAL AREAS (PR-OS1) 1.735 98 Paved parking, HSG B (PR1-1) 0.348 98 Roofs, HSG B (PR1-1) 19.657 59 TOTAL AREA Existing Conditions Type III 24-hr 1 Inch Rainfall=1.00"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 3HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Depth= 0.00" Routed to Pond OS 1P : Offsite Basin Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 1 Inch Rainfall=1.00" Area (ac) CN Description * 16.070 53 OFF SITE RESIDENTIAL AREAS 0.024 61 >75% Grass cover, Good, HSG B 0.429 69 50-75% Grass cover, Fair, HSG B 16.523 53 Weighted Average 16.523 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, 0.3 180 0.0070 9.24 16.32 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.007 1.0 98 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 31.3 278 Total Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 1 Inch Rainfall=1.00" Runoff Area=16.523 ac Runoff Volume=0.000 af Runoff Depth=0.00" Flow Length=278' Tc=31.3 min CN=53 0.00 cfs Existing Conditions Type III 24-hr 1 Inch Rainfall=1.00"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 4HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-1: Project Site Runoff = 0.90 cfs @ 12.10 hrs, Volume= 0.070 af, Depth= 0.28" Routed to Pond 1P : Surface/Subsurface Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 1 Inch Rainfall=1.00" Area (sf) CN Description 37,938 69 50-75% Grass cover, Fair, HSG B 75,564 98 Paved parking, HSG B 15,171 98 Roofs, HSG B 128,673 89 Weighted Average 37,938 29.48% Pervious Area 90,735 70.52% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR1-1: Project Site Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 1 Inch Rainfall=1.00" Runoff Area=128,673 sf Runoff Volume=0.070 af Runoff Depth=0.28" Tc=6.0 min CN=89 0.90 cfs Existing Conditions Type III 24-hr 1 Inch Rainfall=1.00"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 5HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-2: South and Rear Grassed Area Runoff = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Depth= 0.00" Routed to Link POA-1A : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 1 Inch Rainfall=1.00" Area (sf) CN Description 7,839 61 >75% Grass cover, Good, HSG B 7,839 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.8 100 0.1000 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.50" 1.4 263 0.0400 3.22 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 12.2 363 Total Subcatchment PR1-2: South and Rear Grassed Area Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 1 Inch Rainfall=1.00" Runoff Area=7,839 sf Runoff Volume=0.000 af Runoff Depth=0.00" Flow Length=363' Tc=12.2 min CN=61 0.00 cfs Existing Conditions Type III 24-hr 1 Inch Rainfall=1.00"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 6HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond 1P: Surface/Subsurface Detention Inflow Area = 2.954 ac, 70.52% Impervious, Inflow Depth = 0.28" for 1 Inch event Inflow = 0.90 cfs @ 12.10 hrs, Volume= 0.070 af Outflow = 0.19 cfs @ 12.59 hrs, Volume= 0.070 af, Atten= 79%, Lag= 29.3 min Discarded = 0.19 cfs @ 12.59 hrs, Volume= 0.070 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link POA-1A : Galvin Lane Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 142.28' @ 12.59 hrs Surf.Area= 7,595 sf Storage= 859 cf Plug-Flow detention time= 43.4 min calculated for 0.070 af (100% of inflow) Center-of-Mass det. time= 43.2 min ( 913.1 - 869.9 ) Volume Invert Avail.Storage Storage Description #1 146.00' 17,407 cf Detention Basin 1 (Irregular) Listed below (Recalc) #2A 142.00' 12,528 cf 49.00'W x 155.00'L x 8.00'H Field A 60,760 cf Overall - 29,441 cf Embedded = 31,319 cf x 40.0% Voids #3A 142.50' 29,441 cf CMP Round 84 x 35 Inside #2 Effective Size= 84.0"W x 84.0"H => 38.48 sf x 20.00'L = 769.7 cf Overall Size= 84.0"W x 84.0"H x 20.00'L Row Length Adjustment= +13.00' x 38.48 sf x 5 rows 59,375 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 146.00 991 163.0 0 0 991 147.00 1,528 186.0 1,250 1,250 1,653 148.00 2,135 209.0 1,823 3,073 2,403 150.00 3,553 254.0 5,628 8,701 4,124 151.00 4,345 273.0 3,942 12,643 4,963 152.00 5,194 292.0 4,763 17,407 5,863 Device Routing Invert Outlet Devices #1 Primary 146.00'12.0" Round Culvert L= 15.0' Ke= 0.500 Inlet / Outlet Invert= 146.00' / 145.70' S= 0.0200 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf #2 Device 1 146.00'6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 151.20'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #4 Discarded 142.00'1.020 in/hr Exfiltration over Surface area from 141.00' - 146.00' Conductivity to Groundwater Elevation = 136.00' Excluded Surface area = 0 sf Existing Conditions Type III 24-hr 1 Inch Rainfall=1.00"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 7HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.19 cfs @ 12.59 hrs HW=142.28' (Free Discharge) 4=Exfiltration ( Controls 0.19 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=142.00' (Free Discharge) 1=Culvert ( Controls 0.00 cfs) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond 1P: Surface/Subsurface Detention Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=2.954 ac Peak Elev=142.28' Storage=859 cf 0.90 cfs 0.19 cfs 0.19 cfs 0.00 cfs Existing Conditions Type III 24-hr 1 Inch Rainfall=1.00"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 8HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond OS 1P: Offsite Basin Inflow Area = 16.523 ac, 0.00% Impervious, Inflow Depth = 0.00" for 1 Inch event Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link POA-1A : Galvin Lane Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Pond 1P : Surface/Subsurface Detention Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 148.00' @ 0.00 hrs Surf.Area= 1,856 sf Storage= 0 cf Plug-Flow detention time= (not calculated: initial storage exceeds outflow) Center-of-Mass det. time= (not calculated: no inflow) Volume Invert Avail.Storage Storage Description #1 148.00' 21,446 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 148.00 1,856 257.0 0 0 1,856 150.00 3,729 332.0 5,477 5,477 5,420 151.00 4,768 354.0 4,238 9,715 6,669 152.00 5,860 373.0 5,305 15,020 7,827 153.00 7,009 392.0 6,426 21,446 9,045 Device Routing Invert Outlet Devices #1 Primary 148.00'18.0" Round Culvert L= 190.0' Ke= 0.500 Inlet / Outlet Invert= 148.00' / 142.00' S= 0.0316 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 1.77 sf #2 Device 1 148.00'20.0" W x 12.0" H Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 150.00'12.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #4 Secondary 151.50'20.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Existing Conditions Type III 24-hr 1 Inch Rainfall=1.00"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 9HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=148.00' (Free Discharge) 1=Culvert ( Controls 0.00 cfs) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=148.00' (Free Discharge) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond OS 1P: Offsite Basin Inflow Outflow Primary Secondary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=16.523 ac Peak Elev=148.00' Storage=0 cf 0.00 cfs 0.00 cfs 0.00 cfs 0.00 cfs Existing Conditions Type III 24-hr 1 Inch Rainfall=1.00"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 10HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Link POA-1A: Galvin Lane Inflow Area = 19.657 ac, 10.60% Impervious, Inflow Depth = 0.00" for 1 Inch event Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Link POA-1A: Galvin Lane Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=19.657 ac 0.00 cfs 0.00 cfs Existing Conditions Type III 24-hr 1 Year Rainfall=2.90"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 11HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff = 0.33 cfs @ 13.05 hrs, Volume= 0.175 af, Depth= 0.13" Routed to Pond OS 1P : Offsite Basin Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 1 Year Rainfall=2.90" Area (ac) CN Description * 16.070 53 OFF SITE RESIDENTIAL AREAS 0.024 61 >75% Grass cover, Good, HSG B 0.429 69 50-75% Grass cover, Fair, HSG B 16.523 53 Weighted Average 16.523 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, 0.3 180 0.0070 9.24 16.32 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.007 1.0 98 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 31.3 278 Total Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type III 24-hr 1 Year Rainfall=2.90" Runoff Area=16.523 ac Runoff Volume=0.175 af Runoff Depth=0.13" Flow Length=278' Tc=31.3 min CN=53 0.33 cfs Existing Conditions Type III 24-hr 1 Year Rainfall=2.90"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 12HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-1: Project Site Runoff = 6.21 cfs @ 12.09 hrs, Volume= 0.445 af, Depth= 1.81" Routed to Pond 1P : Surface/Subsurface Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 1 Year Rainfall=2.90" Area (sf) CN Description 37,938 69 50-75% Grass cover, Fair, HSG B 75,564 98 Paved parking, HSG B 15,171 98 Roofs, HSG B 128,673 89 Weighted Average 37,938 29.48% Pervious Area 90,735 70.52% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR1-1: Project Site Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)6 5 4 3 2 1 0 Type III 24-hr 1 Year Rainfall=2.90" Runoff Area=128,673 sf Runoff Volume=0.445 af Runoff Depth=1.81" Tc=6.0 min CN=89 6.21 cfs Existing Conditions Type III 24-hr 1 Year Rainfall=2.90"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 13HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-2: South and Rear Grassed Area Runoff = 0.03 cfs @ 12.32 hrs, Volume= 0.005 af, Depth= 0.33" Routed to Link POA-1A : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 1 Year Rainfall=2.90" Area (sf) CN Description 7,839 61 >75% Grass cover, Good, HSG B 7,839 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.8 100 0.1000 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.50" 1.4 263 0.0400 3.22 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 12.2 363 Total Subcatchment PR1-2: South and Rear Grassed Area Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.032 0.03 0.028 0.026 0.024 0.022 0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0 Type III 24-hr 1 Year Rainfall=2.90" Runoff Area=7,839 sf Runoff Volume=0.005 af Runoff Depth=0.33" Flow Length=363' Tc=12.2 min CN=61 0.03 cfs Existing Conditions Type III 24-hr 1 Year Rainfall=2.90"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 14HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond 1P: Surface/Subsurface Detention Inflow Area = 2.954 ac, 70.52% Impervious, Inflow Depth = 1.81" for 1 Year event Inflow = 6.21 cfs @ 12.09 hrs, Volume= 0.445 af Outflow = 0.25 cfs @ 15.47 hrs, Volume= 0.445 af, Atten= 96%, Lag= 203.1 min Discarded = 0.25 cfs @ 15.47 hrs, Volume= 0.445 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link POA-1A : Galvin Lane Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 144.38' @ 15.47 hrs Surf.Area= 7,595 sf Storage= 11,059 cf Plug-Flow detention time= 466.7 min calculated for 0.445 af (100% of inflow) Center-of-Mass det. time= 466.7 min ( 1,281.7 - 815.1 ) Volume Invert Avail.Storage Storage Description #1 146.00' 17,407 cf Detention Basin 1 (Irregular) Listed below (Recalc) #2A 142.00' 12,528 cf 49.00'W x 155.00'L x 8.00'H Field A 60,760 cf Overall - 29,441 cf Embedded = 31,319 cf x 40.0% Voids #3A 142.50' 29,441 cf CMP Round 84 x 35 Inside #2 Effective Size= 84.0"W x 84.0"H => 38.48 sf x 20.00'L = 769.7 cf Overall Size= 84.0"W x 84.0"H x 20.00'L Row Length Adjustment= +13.00' x 38.48 sf x 5 rows 59,375 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 146.00 991 163.0 0 0 991 147.00 1,528 186.0 1,250 1,250 1,653 148.00 2,135 209.0 1,823 3,073 2,403 150.00 3,553 254.0 5,628 8,701 4,124 151.00 4,345 273.0 3,942 12,643 4,963 152.00 5,194 292.0 4,763 17,407 5,863 Device Routing Invert Outlet Devices #1 Primary 146.00'12.0" Round Culvert L= 15.0' Ke= 0.500 Inlet / Outlet Invert= 146.00' / 145.70' S= 0.0200 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf #2 Device 1 146.00'6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 151.20'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #4 Discarded 142.00'1.020 in/hr Exfiltration over Surface area from 141.00' - 146.00' Conductivity to Groundwater Elevation = 136.00' Excluded Surface area = 0 sf Existing Conditions Type III 24-hr 1 Year Rainfall=2.90"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 15HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.25 cfs @ 15.47 hrs HW=144.38' (Free Discharge) 4=Exfiltration ( Controls 0.25 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=142.00' (Free Discharge) 1=Culvert ( Controls 0.00 cfs) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond 1P: Surface/Subsurface Detention Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)6 5 4 3 2 1 0 Inflow Area=2.954 ac Peak Elev=144.38' Storage=11,059 cf 6.21 cfs 0.25 cfs 0.25 cfs 0.00 cfs Existing Conditions Type III 24-hr 1 Year Rainfall=2.90"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 16HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond OS 1P: Offsite Basin Inflow Area = 16.523 ac, 0.00% Impervious, Inflow Depth = 0.13" for 1 Year event Inflow = 0.33 cfs @ 13.05 hrs, Volume= 0.175 af Outflow = 0.31 cfs @ 13.87 hrs, Volume= 0.175 af, Atten= 7%, Lag= 48.7 min Primary = 0.31 cfs @ 13.87 hrs, Volume= 0.175 af Routed to Link POA-1A : Galvin Lane Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Pond 1P : Surface/Subsurface Detention Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 148.24' @ 13.87 hrs Surf.Area= 2,047 sf Storage= 468 cf Plug-Flow detention time= 33.9 min calculated for 0.175 af (100% of inflow) Center-of-Mass det. time= 34.2 min ( 1,060.2 - 1,026.0 ) Volume Invert Avail.Storage Storage Description #1 148.00' 21,446 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 148.00 1,856 257.0 0 0 1,856 150.00 3,729 332.0 5,477 5,477 5,420 151.00 4,768 354.0 4,238 9,715 6,669 152.00 5,860 373.0 5,305 15,020 7,827 153.00 7,009 392.0 6,426 21,446 9,045 Device Routing Invert Outlet Devices #1 Primary 148.00'18.0" Round Culvert L= 190.0' Ke= 0.500 Inlet / Outlet Invert= 148.00' / 142.00' S= 0.0316 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 1.77 sf #2 Device 1 148.00'20.0" W x 12.0" H Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 150.00'12.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #4 Secondary 151.50'20.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Existing Conditions Type III 24-hr 1 Year Rainfall=2.90"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 17HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Primary OutFlow Max=0.30 cfs @ 13.87 hrs HW=148.24' (Free Discharge) 1=Culvert (Inlet Controls 0.30 cfs @ 1.67 fps) 2=Orifice/Grate (Passes 0.30 cfs of 0.63 cfs potential flow) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=148.00' (Free Discharge) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond OS 1P: Offsite Basin Inflow Outflow Primary Secondary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=16.523 ac Peak Elev=148.24' Storage=468 cf 0.33 cfs 0.31 cfs 0.31 cfs 0.00 cfs Existing Conditions Type III 24-hr 1 Year Rainfall=2.90"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 18HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Link POA-1A: Galvin Lane Inflow Area = 19.657 ac, 10.60% Impervious, Inflow Depth > 0.11" for 1 Year event Inflow = 0.31 cfs @ 13.83 hrs, Volume= 0.180 af Primary = 0.31 cfs @ 13.83 hrs, Volume= 0.180 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Link POA-1A: Galvin Lane Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Inflow Area=19.657 ac 0.31 cfs 0.31 cfs Existing Conditions Type III 24-hr 2 Year Rainfall=3.46"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 19HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff = 1.31 cfs @ 12.70 hrs, Volume= 0.371 af, Depth= 0.27" Routed to Pond OS 1P : Offsite Basin Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 2 Year Rainfall=3.46" Area (ac) CN Description * 16.070 53 OFF SITE RESIDENTIAL AREAS 0.024 61 >75% Grass cover, Good, HSG B 0.429 69 50-75% Grass cover, Fair, HSG B 16.523 53 Weighted Average 16.523 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, 0.3 180 0.0070 9.24 16.32 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.007 1.0 98 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 31.3 278 Total Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Type III 24-hr 2 Year Rainfall=3.46" Runoff Area=16.523 ac Runoff Volume=0.371 af Runoff Depth=0.27" Flow Length=278' Tc=31.3 min CN=53 1.31 cfs Existing Conditions Type III 24-hr 2 Year Rainfall=3.46"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 20HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-1: Project Site Runoff = 7.92 cfs @ 12.09 hrs, Volume= 0.571 af, Depth= 2.32" Routed to Pond 1P : Surface/Subsurface Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 2 Year Rainfall=3.46" Area (sf) CN Description 37,938 69 50-75% Grass cover, Fair, HSG B 75,564 98 Paved parking, HSG B 15,171 98 Roofs, HSG B 128,673 89 Weighted Average 37,938 29.48% Pervious Area 90,735 70.52% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR1-1: Project Site Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 Type III 24-hr 2 Year Rainfall=3.46" Runoff Area=128,673 sf Runoff Volume=0.571 af Runoff Depth=2.32" Tc=6.0 min CN=89 7.92 cfs Existing Conditions Type III 24-hr 2 Year Rainfall=3.46"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 21HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-2: South and Rear Grassed Area Runoff = 0.07 cfs @ 12.22 hrs, Volume= 0.008 af, Depth= 0.55" Routed to Link POA-1A : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 2 Year Rainfall=3.46" Area (sf) CN Description 7,839 61 >75% Grass cover, Good, HSG B 7,839 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.8 100 0.1000 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.50" 1.4 263 0.0400 3.22 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 12.2 363 Total Subcatchment PR1-2: South and Rear Grassed Area Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.07 0.065 0.06 0.055 0.05 0.045 0.04 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 Type III 24-hr 2 Year Rainfall=3.46" Runoff Area=7,839 sf Runoff Volume=0.008 af Runoff Depth=0.55" Flow Length=363' Tc=12.2 min CN=61 0.07 cfs Existing Conditions Type III 24-hr 2 Year Rainfall=3.46"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 22HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond 1P: Surface/Subsurface Detention Inflow Area = 2.954 ac, 70.52% Impervious, Inflow Depth = 2.32" for 2 Year event Inflow = 7.92 cfs @ 12.09 hrs, Volume= 0.571 af Outflow = 0.27 cfs @ 15.84 hrs, Volume= 0.532 af, Atten= 97%, Lag= 224.9 min Discarded = 0.27 cfs @ 15.84 hrs, Volume= 0.532 af Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Link POA-1A : Galvin Lane Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 145.04' @ 15.84 hrs Surf.Area= 7,595 sf Storage= 15,050 cf Plug-Flow detention time= 561.7 min calculated for 0.532 af (93% of inflow) Center-of-Mass det. time= 525.9 min ( 1,333.9 - 808.0 ) Volume Invert Avail.Storage Storage Description #1 146.00' 17,407 cf Detention Basin 1 (Irregular) Listed below (Recalc) #2A 142.00' 12,528 cf 49.00'W x 155.00'L x 8.00'H Field A 60,760 cf Overall - 29,441 cf Embedded = 31,319 cf x 40.0% Voids #3A 142.50' 29,441 cf CMP Round 84 x 35 Inside #2 Effective Size= 84.0"W x 84.0"H => 38.48 sf x 20.00'L = 769.7 cf Overall Size= 84.0"W x 84.0"H x 20.00'L Row Length Adjustment= +13.00' x 38.48 sf x 5 rows 59,375 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 146.00 991 163.0 0 0 991 147.00 1,528 186.0 1,250 1,250 1,653 148.00 2,135 209.0 1,823 3,073 2,403 150.00 3,553 254.0 5,628 8,701 4,124 151.00 4,345 273.0 3,942 12,643 4,963 152.00 5,194 292.0 4,763 17,407 5,863 Device Routing Invert Outlet Devices #1 Primary 146.00'12.0" Round Culvert L= 15.0' Ke= 0.500 Inlet / Outlet Invert= 146.00' / 145.70' S= 0.0200 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf #2 Device 1 146.00'6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 151.20'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #4 Discarded 142.00'1.020 in/hr Exfiltration over Surface area from 141.00' - 146.00' Conductivity to Groundwater Elevation = 136.00' Excluded Surface area = 0 sf Existing Conditions Type III 24-hr 2 Year Rainfall=3.46"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 23HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.27 cfs @ 15.84 hrs HW=145.04' (Free Discharge) 4=Exfiltration ( Controls 0.27 cfs) Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=142.00' (Free Discharge) 1=Culvert ( Controls 0.00 cfs) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond 1P: Surface/Subsurface Detention Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 Inflow Area=2.954 ac Peak Elev=145.04' Storage=15,050 cf 7.92 cfs 0.27 cfs 0.27 cfs 0.00 cfs Existing Conditions Type III 24-hr 2 Year Rainfall=3.46"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 24HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond OS 1P: Offsite Basin Inflow Area = 16.523 ac, 0.00% Impervious, Inflow Depth = 0.27" for 2 Year event Inflow = 1.31 cfs @ 12.70 hrs, Volume= 0.371 af Outflow = 1.15 cfs @ 12.90 hrs, Volume= 0.371 af, Atten= 12%, Lag= 12.0 min Primary = 1.15 cfs @ 12.90 hrs, Volume= 0.371 af Routed to Link POA-1A : Galvin Lane Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Pond 1P : Surface/Subsurface Detention Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 148.48' @ 12.90 hrs Surf.Area= 2,246 sf Storage= 981 cf Plug-Flow detention time= 23.8 min calculated for 0.371 af (100% of inflow) Center-of-Mass det. time= 23.7 min ( 1,003.0 - 979.3 ) Volume Invert Avail.Storage Storage Description #1 148.00' 21,446 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 148.00 1,856 257.0 0 0 1,856 150.00 3,729 332.0 5,477 5,477 5,420 151.00 4,768 354.0 4,238 9,715 6,669 152.00 5,860 373.0 5,305 15,020 7,827 153.00 7,009 392.0 6,426 21,446 9,045 Device Routing Invert Outlet Devices #1 Primary 148.00'18.0" Round Culvert L= 190.0' Ke= 0.500 Inlet / Outlet Invert= 148.00' / 142.00' S= 0.0316 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 1.77 sf #2 Device 1 148.00'20.0" W x 12.0" H Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 150.00'12.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #4 Secondary 151.50'20.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Existing Conditions Type III 24-hr 2 Year Rainfall=3.46"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 25HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Primary OutFlow Max=1.15 cfs @ 12.90 hrs HW=148.48' (Free Discharge) 1=Culvert (Inlet Controls 1.15 cfs @ 2.36 fps) 2=Orifice/Grate (Passes 1.15 cfs of 1.77 cfs potential flow) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=148.00' (Free Discharge) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond OS 1P: Offsite Basin Inflow Outflow Primary Secondary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=16.523 ac Peak Elev=148.48' Storage=981 cf 1.31 cfs 1.15 cfs 1.15 cfs 0.00 cfs Existing Conditions Type III 24-hr 2 Year Rainfall=3.46"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 26HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Link POA-1A: Galvin Lane Inflow Area = 19.657 ac, 10.60% Impervious, Inflow Depth = 0.23" for 2 Year event Inflow = 1.17 cfs @ 12.90 hrs, Volume= 0.379 af Primary = 1.17 cfs @ 12.90 hrs, Volume= 0.379 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Link POA-1A: Galvin Lane Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)1 0 Inflow Area=19.657 ac 1.17 cfs 1.17 cfs Existing Conditions Type III 24-hr 10 Year Rainfall=5.12"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 27HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff = 7.68 cfs @ 12.54 hrs, Volume= 1.262 af, Depth= 0.92" Routed to Pond OS 1P : Offsite Basin Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 10 Year Rainfall=5.12" Area (ac) CN Description * 16.070 53 OFF SITE RESIDENTIAL AREAS 0.024 61 >75% Grass cover, Good, HSG B 0.429 69 50-75% Grass cover, Fair, HSG B 16.523 53 Weighted Average 16.523 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, 0.3 180 0.0070 9.24 16.32 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.007 1.0 98 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 31.3 278 Total Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 Type III 24-hr 10 Year Rainfall=5.12" Runoff Area=16.523 ac Runoff Volume=1.262 af Runoff Depth=0.92" Flow Length=278' Tc=31.3 min CN=53 7.68 cfs Existing Conditions Type III 24-hr 10 Year Rainfall=5.12"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 28HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-1: Project Site Runoff = 12.98 cfs @ 12.09 hrs, Volume= 0.957 af, Depth= 3.89" Routed to Pond 1P : Surface/Subsurface Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 10 Year Rainfall=5.12" Area (sf) CN Description 37,938 69 50-75% Grass cover, Fair, HSG B 75,564 98 Paved parking, HSG B 15,171 98 Roofs, HSG B 128,673 89 Weighted Average 37,938 29.48% Pervious Area 90,735 70.52% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR1-1: Project Site Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 10 Year Rainfall=5.12" Runoff Area=128,673 sf Runoff Volume=0.957 af Runoff Depth=3.89" Tc=6.0 min CN=89 12.98 cfs Existing Conditions Type III 24-hr 10 Year Rainfall=5.12"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 29HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-2: South and Rear Grassed Area Runoff = 0.23 cfs @ 12.19 hrs, Volume= 0.022 af, Depth= 1.44" Routed to Link POA-1A : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 10 Year Rainfall=5.12" Area (sf) CN Description 7,839 61 >75% Grass cover, Good, HSG B 7,839 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.8 100 0.1000 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.50" 1.4 263 0.0400 3.22 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 12.2 363 Total Subcatchment PR1-2: South and Rear Grassed Area Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.25 0.24 0.23 0.22 0.21 0.2 0.19 0.18 0.17 0.16 0.15 0.14 0.13 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 Type III 24-hr 10 Year Rainfall=5.12" Runoff Area=7,839 sf Runoff Volume=0.022 af Runoff Depth=1.44" Flow Length=363' Tc=12.2 min CN=61 0.23 cfs Existing Conditions Type III 24-hr 10 Year Rainfall=5.12"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 30HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond 1P: Surface/Subsurface Detention Inflow Area = 2.954 ac, 70.52% Impervious, Inflow Depth = 3.89" for 10 Year event Inflow = 12.98 cfs @ 12.09 hrs, Volume= 0.957 af Outflow = 0.76 cfs @ 13.93 hrs, Volume= 0.777 af, Atten= 94%, Lag= 110.9 min Discarded = 0.34 cfs @ 13.93 hrs, Volume= 0.649 af Primary = 0.42 cfs @ 13.93 hrs, Volume= 0.128 af Routed to Link POA-1A : Galvin Lane Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 146.45' @ 13.93 hrs Surf.Area= 8,813 sf Storage= 24,287 cf Plug-Flow detention time= 514.3 min calculated for 0.777 af (81% of inflow) Center-of-Mass det. time= 441.5 min ( 1,235.0 - 793.6 ) Volume Invert Avail.Storage Storage Description #1 146.00' 17,407 cf Detention Basin 1 (Irregular) Listed below (Recalc) #2A 142.00' 12,528 cf 49.00'W x 155.00'L x 8.00'H Field A 60,760 cf Overall - 29,441 cf Embedded = 31,319 cf x 40.0% Voids #3A 142.50' 29,441 cf CMP Round 84 x 35 Inside #2 Effective Size= 84.0"W x 84.0"H => 38.48 sf x 20.00'L = 769.7 cf Overall Size= 84.0"W x 84.0"H x 20.00'L Row Length Adjustment= +13.00' x 38.48 sf x 5 rows 59,375 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 146.00 991 163.0 0 0 991 147.00 1,528 186.0 1,250 1,250 1,653 148.00 2,135 209.0 1,823 3,073 2,403 150.00 3,553 254.0 5,628 8,701 4,124 151.00 4,345 273.0 3,942 12,643 4,963 152.00 5,194 292.0 4,763 17,407 5,863 Device Routing Invert Outlet Devices #1 Primary 146.00'12.0" Round Culvert L= 15.0' Ke= 0.500 Inlet / Outlet Invert= 146.00' / 145.70' S= 0.0200 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf #2 Device 1 146.00'6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 151.20'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #4 Discarded 142.00'1.020 in/hr Exfiltration over Surface area from 141.00' - 146.00' Conductivity to Groundwater Elevation = 136.00' Excluded Surface area = 0 sf Existing Conditions Type III 24-hr 10 Year Rainfall=5.12"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 31HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.34 cfs @ 13.93 hrs HW=146.45' (Free Discharge) 4=Exfiltration ( Controls 0.34 cfs) Primary OutFlow Max=0.42 cfs @ 13.93 hrs HW=146.45' (Free Discharge) 1=Culvert (Passes 0.42 cfs of 0.78 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.42 cfs @ 2.28 fps) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond 1P: Surface/Subsurface Detention Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=2.954 ac Peak Elev=146.45' Storage=24,287 cf 12.98 cfs 0.76 cfs 0.34 cfs 0.42 cfs Existing Conditions Type III 24-hr 10 Year Rainfall=5.12"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 32HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond OS 1P: Offsite Basin Inflow Area = 16.523 ac, 0.00% Impervious, Inflow Depth = 0.92" for 10 Year event Inflow = 7.68 cfs @ 12.54 hrs, Volume= 1.262 af Outflow = 7.02 cfs @ 12.67 hrs, Volume= 1.262 af, Atten= 9%, Lag= 8.0 min Primary = 7.02 cfs @ 12.67 hrs, Volume= 1.262 af Routed to Link POA-1A : Galvin Lane Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Pond 1P : Surface/Subsurface Detention Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 149.42' @ 12.67 hrs Surf.Area= 3,120 sf Storage= 3,495 cf Plug-Flow detention time= 13.3 min calculated for 1.261 af (100% of inflow) Center-of-Mass det. time= 13.5 min ( 935.2 - 921.8 ) Volume Invert Avail.Storage Storage Description #1 148.00' 21,446 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 148.00 1,856 257.0 0 0 1,856 150.00 3,729 332.0 5,477 5,477 5,420 151.00 4,768 354.0 4,238 9,715 6,669 152.00 5,860 373.0 5,305 15,020 7,827 153.00 7,009 392.0 6,426 21,446 9,045 Device Routing Invert Outlet Devices #1 Primary 148.00'18.0" Round Culvert L= 190.0' Ke= 0.500 Inlet / Outlet Invert= 148.00' / 142.00' S= 0.0316 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 1.77 sf #2 Device 1 148.00'20.0" W x 12.0" H Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 150.00'12.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #4 Secondary 151.50'20.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Existing Conditions Type III 24-hr 10 Year Rainfall=5.12"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 33HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Primary OutFlow Max=7.02 cfs @ 12.67 hrs HW=149.42' (Free Discharge) 1=Culvert (Inlet Controls 7.02 cfs @ 4.06 fps) 2=Orifice/Grate (Passes 7.02 cfs of 7.59 cfs potential flow) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=148.00' (Free Discharge) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond OS 1P: Offsite Basin Inflow Outflow Primary Secondary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 Inflow Area=16.523 ac Peak Elev=149.42' Storage=3,495 cf 7.68 cfs 7.02 cfs 7.02 cfs 0.00 cfs Existing Conditions Type III 24-hr 10 Year Rainfall=5.12"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 34HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Link POA-1A: Galvin Lane Inflow Area = 19.657 ac, 10.60% Impervious, Inflow Depth = 0.86" for 10 Year event Inflow = 7.23 cfs @ 12.68 hrs, Volume= 1.412 af Primary = 7.23 cfs @ 12.68 hrs, Volume= 1.412 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Link POA-1A: Galvin Lane Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)8 7 6 5 4 3 2 1 0 Inflow Area=19.657 ac 7.23 cfs 7.23 cfs Existing Conditions Type III 24-hr 25 Year Rainfall=6.16"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 35HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff = 13.55 cfs @ 12.50 hrs, Volume= 1.999 af, Depth= 1.45" Routed to Pond OS 1P : Offsite Basin Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 25 Year Rainfall=6.16" Area (ac) CN Description * 16.070 53 OFF SITE RESIDENTIAL AREAS 0.024 61 >75% Grass cover, Good, HSG B 0.429 69 50-75% Grass cover, Fair, HSG B 16.523 53 Weighted Average 16.523 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, 0.3 180 0.0070 9.24 16.32 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.007 1.0 98 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 31.3 278 Total Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25 Year Rainfall=6.16" Runoff Area=16.523 ac Runoff Volume=1.999 af Runoff Depth=1.45" Flow Length=278' Tc=31.3 min CN=53 13.55 cfs Existing Conditions Type III 24-hr 25 Year Rainfall=6.16"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 36HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-1: Project Site Runoff = 16.14 cfs @ 12.09 hrs, Volume= 1.204 af, Depth= 4.89" Routed to Pond 1P : Surface/Subsurface Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 25 Year Rainfall=6.16" Area (sf) CN Description 37,938 69 50-75% Grass cover, Fair, HSG B 75,564 98 Paved parking, HSG B 15,171 98 Roofs, HSG B 128,673 89 Weighted Average 37,938 29.48% Pervious Area 90,735 70.52% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR1-1: Project Site Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25 Year Rainfall=6.16" Runoff Area=128,673 sf Runoff Volume=1.204 af Runoff Depth=4.89" Tc=6.0 min CN=89 16.14 cfs Existing Conditions Type III 24-hr 25 Year Rainfall=6.16"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 37HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-2: South and Rear Grassed Area Runoff = 0.35 cfs @ 12.18 hrs, Volume= 0.032 af, Depth= 2.11" Routed to Link POA-1A : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 25 Year Rainfall=6.16" Area (sf) CN Description 7,839 61 >75% Grass cover, Good, HSG B 7,839 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.8 100 0.1000 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.50" 1.4 263 0.0400 3.22 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 12.2 363 Total Subcatchment PR1-2: South and Rear Grassed Area Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.38 0.36 0.34 0.32 0.3 0.28 0.26 0.24 0.22 0.2 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 Type III 24-hr 25 Year Rainfall=6.16" Runoff Area=7,839 sf Runoff Volume=0.032 af Runoff Depth=2.11" Flow Length=363' Tc=12.2 min CN=61 0.35 cfs Existing Conditions Type III 24-hr 25 Year Rainfall=6.16"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 38HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond 1P: Surface/Subsurface Detention Inflow Area = 2.954 ac, 70.52% Impervious, Inflow Depth = 4.89" for 25 Year event Inflow = 16.14 cfs @ 12.09 hrs, Volume= 1.204 af Outflow = 1.22 cfs @ 13.23 hrs, Volume= 1.007 af, Atten= 92%, Lag= 68.7 min Discarded = 0.36 cfs @ 13.23 hrs, Volume= 0.680 af Primary = 0.86 cfs @ 13.23 hrs, Volume= 0.327 af Routed to Link POA-1A : Galvin Lane Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 147.08' @ 13.23 hrs Surf.Area= 9,168 sf Storage= 29,059 cf Plug-Flow detention time= 436.9 min calculated for 1.007 af (84% of inflow) Center-of-Mass det. time= 369.7 min ( 1,157.1 - 787.3 ) Volume Invert Avail.Storage Storage Description #1 146.00' 17,407 cf Detention Basin 1 (Irregular) Listed below (Recalc) #2A 142.00' 12,528 cf 49.00'W x 155.00'L x 8.00'H Field A 60,760 cf Overall - 29,441 cf Embedded = 31,319 cf x 40.0% Voids #3A 142.50' 29,441 cf CMP Round 84 x 35 Inside #2 Effective Size= 84.0"W x 84.0"H => 38.48 sf x 20.00'L = 769.7 cf Overall Size= 84.0"W x 84.0"H x 20.00'L Row Length Adjustment= +13.00' x 38.48 sf x 5 rows 59,375 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 146.00 991 163.0 0 0 991 147.00 1,528 186.0 1,250 1,250 1,653 148.00 2,135 209.0 1,823 3,073 2,403 150.00 3,553 254.0 5,628 8,701 4,124 151.00 4,345 273.0 3,942 12,643 4,963 152.00 5,194 292.0 4,763 17,407 5,863 Device Routing Invert Outlet Devices #1 Primary 146.00'12.0" Round Culvert L= 15.0' Ke= 0.500 Inlet / Outlet Invert= 146.00' / 145.70' S= 0.0200 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf #2 Device 1 146.00'6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 151.20'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #4 Discarded 142.00'1.020 in/hr Exfiltration over Surface area from 141.00' - 146.00' Conductivity to Groundwater Elevation = 136.00' Excluded Surface area = 0 sf Existing Conditions Type III 24-hr 25 Year Rainfall=6.16"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 39HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.36 cfs @ 13.23 hrs HW=147.08' (Free Discharge) 4=Exfiltration ( Controls 0.36 cfs) Primary OutFlow Max=0.86 cfs @ 13.23 hrs HW=147.08' (Free Discharge) 1=Culvert (Passes 0.86 cfs of 2.88 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.86 cfs @ 4.39 fps) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond 1P: Surface/Subsurface Detention Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=2.954 ac Peak Elev=147.08' Storage=29,059 cf 16.14 cfs 1.22 cfs 0.36 cfs0.86 cfs Existing Conditions Type III 24-hr 25 Year Rainfall=6.16"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 40HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond OS 1P: Offsite Basin Inflow Area = 16.523 ac, 0.00% Impervious, Inflow Depth = 1.45" for 25 Year event Inflow = 13.55 cfs @ 12.50 hrs, Volume= 1.999 af Outflow = 11.15 cfs @ 12.71 hrs, Volume= 1.999 af, Atten= 18%, Lag= 12.3 min Primary = 11.15 cfs @ 12.71 hrs, Volume= 1.999 af Routed to Link POA-1A : Galvin Lane Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af Routed to Pond 1P : Surface/Subsurface Detention Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 150.47' @ 12.71 hrs Surf.Area= 4,197 sf Storage= 7,324 cf Plug-Flow detention time= 12.3 min calculated for 1.999 af (100% of inflow) Center-of-Mass det. time= 12.1 min ( 917.0 - 904.8 ) Volume Invert Avail.Storage Storage Description #1 148.00' 21,446 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 148.00 1,856 257.0 0 0 1,856 150.00 3,729 332.0 5,477 5,477 5,420 151.00 4,768 354.0 4,238 9,715 6,669 152.00 5,860 373.0 5,305 15,020 7,827 153.00 7,009 392.0 6,426 21,446 9,045 Device Routing Invert Outlet Devices #1 Primary 148.00'18.0" Round Culvert L= 190.0' Ke= 0.500 Inlet / Outlet Invert= 148.00' / 142.00' S= 0.0316 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 1.77 sf #2 Device 1 148.00'20.0" W x 12.0" H Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 150.00'12.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #4 Secondary 151.50'20.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Existing Conditions Type III 24-hr 25 Year Rainfall=6.16"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 41HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Primary OutFlow Max=11.14 cfs @ 12.71 hrs HW=150.46' (Free Discharge) 1=Culvert (Inlet Controls 11.14 cfs @ 6.30 fps) 2=Orifice/Grate (Passes < 11.22 cfs potential flow) 3=Broad-Crested Rectangular Weir (Passes < 10.38 cfs potential flow) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=148.00' (Free Discharge) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond OS 1P: Offsite Basin Inflow Outflow Primary Secondary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=16.523 ac Peak Elev=150.47' Storage=7,324 cf 13.55 cfs 11.15 cfs 11.15 cfs 0.00 cfs Existing Conditions Type III 24-hr 25 Year Rainfall=6.16"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 42HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Link POA-1A: Galvin Lane Inflow Area = 19.657 ac, 10.60% Impervious, Inflow Depth = 1.44" for 25 Year event Inflow = 12.05 cfs @ 12.71 hrs, Volume= 2.358 af Primary = 12.05 cfs @ 12.71 hrs, Volume= 2.358 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Link POA-1A: Galvin Lane Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=19.657 ac 12.05 cfs 12.05 cfs Existing Conditions Type III 24-hr 100 Year Rainfall=7.76"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 43HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff = 24.28 cfs @ 12.48 hrs, Volume= 3.322 af, Depth= 2.41" Routed to Pond OS 1P : Offsite Basin Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 100 Year Rainfall=7.76" Area (ac) CN Description * 16.070 53 OFF SITE RESIDENTIAL AREAS 0.024 61 >75% Grass cover, Good, HSG B 0.429 69 50-75% Grass cover, Fair, HSG B 16.523 53 Weighted Average 16.523 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 30.0 Direct Entry, 0.3 180 0.0070 9.24 16.32 Pipe Channel, 18.0" Round Area= 1.8 sf Perim= 4.7' r= 0.38' n= 0.007 1.0 98 0.0100 1.61 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 31.3 278 Total Subcatchment PR-OS1: Off-Site Residential Area - 16 Acres Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type III 24-hr 100 Year Rainfall=7.76" Runoff Area=16.523 ac Runoff Volume=3.322 af Runoff Depth=2.41" Flow Length=278' Tc=31.3 min CN=53 24.28 cfs Existing Conditions Type III 24-hr 100 Year Rainfall=7.76"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 44HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-1: Project Site Runoff = 20.96 cfs @ 12.09 hrs, Volume= 1.588 af, Depth= 6.45" Routed to Pond 1P : Surface/Subsurface Detention Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 100 Year Rainfall=7.76" Area (sf) CN Description 37,938 69 50-75% Grass cover, Fair, HSG B 75,564 98 Paved parking, HSG B 15,171 98 Roofs, HSG B 128,673 89 Weighted Average 37,938 29.48% Pervious Area 90,735 70.52% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment PR1-1: Project Site Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 100 Year Rainfall=7.76" Runoff Area=128,673 sf Runoff Volume=1.588 af Runoff Depth=6.45" Tc=6.0 min CN=89 20.96 cfs Existing Conditions Type III 24-hr 100 Year Rainfall=7.76"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 45HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Subcatchment PR1-2: South and Rear Grassed Area Runoff = 0.55 cfs @ 12.18 hrs, Volume= 0.049 af, Depth= 3.26" Routed to Link POA-1A : Galvin Lane Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Type III 24-hr 100 Year Rainfall=7.76" Area (sf) CN Description 7,839 61 >75% Grass cover, Good, HSG B 7,839 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.8 100 0.1000 0.15 Sheet Flow, Woods: Light underbrush n= 0.400 P2= 3.50" 1.4 263 0.0400 3.22 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 12.2 363 Total Subcatchment PR1-2: South and Rear Grassed Area Runoff Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 100 Year Rainfall=7.76" Runoff Area=7,839 sf Runoff Volume=0.049 af Runoff Depth=3.26" Flow Length=363' Tc=12.2 min CN=61 0.55 cfs Existing Conditions Type III 24-hr 100 Year Rainfall=7.76"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 46HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond 1P: Surface/Subsurface Detention Inflow Area = 2.954 ac, 70.52% Impervious, Inflow Depth = 7.14" for 100 Year event Inflow = 20.96 cfs @ 12.09 hrs, Volume= 1.757 af Outflow = 2.05 cfs @ 12.94 hrs, Volume= 1.538 af, Atten= 90%, Lag= 51.2 min Discarded = 0.43 cfs @ 12.94 hrs, Volume= 0.738 af Primary = 1.62 cfs @ 12.94 hrs, Volume= 0.800 af Routed to Link POA-1A : Galvin Lane Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 149.20' @ 12.94 hrs Surf.Area= 10,535 sf Storage= 45,356 cf Plug-Flow detention time= 368.0 min calculated for 1.537 af (87% of inflow) Center-of-Mass det. time= 314.4 min ( 1,092.4 - 777.9 ) Volume Invert Avail.Storage Storage Description #1 146.00' 17,407 cf Detention Basin 1 (Irregular) Listed below (Recalc) #2A 142.00' 12,528 cf 49.00'W x 155.00'L x 8.00'H Field A 60,760 cf Overall - 29,441 cf Embedded = 31,319 cf x 40.0% Voids #3A 142.50' 29,441 cf CMP Round 84 x 35 Inside #2 Effective Size= 84.0"W x 84.0"H => 38.48 sf x 20.00'L = 769.7 cf Overall Size= 84.0"W x 84.0"H x 20.00'L Row Length Adjustment= +13.00' x 38.48 sf x 5 rows 59,375 cf Total Available Storage Storage Group A created with Chamber Wizard Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 146.00 991 163.0 0 0 991 147.00 1,528 186.0 1,250 1,250 1,653 148.00 2,135 209.0 1,823 3,073 2,403 150.00 3,553 254.0 5,628 8,701 4,124 151.00 4,345 273.0 3,942 12,643 4,963 152.00 5,194 292.0 4,763 17,407 5,863 Device Routing Invert Outlet Devices #1 Primary 146.00'12.0" Round Culvert L= 15.0' Ke= 0.500 Inlet / Outlet Invert= 146.00' / 145.70' S= 0.0200 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 0.79 sf #2 Device 1 146.00'6.0" Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 151.20'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 #4 Discarded 142.00'1.020 in/hr Exfiltration over Surface area from 141.00' - 146.00' Conductivity to Groundwater Elevation = 136.00' Excluded Surface area = 0 sf Existing Conditions Type III 24-hr 100 Year Rainfall=7.76"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 47HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Discarded OutFlow Max=0.43 cfs @ 12.94 hrs HW=149.20' (Free Discharge) 4=Exfiltration ( Controls 0.43 cfs) Primary OutFlow Max=1.62 cfs @ 12.94 hrs HW=149.20' (Free Discharge) 1=Culvert (Passes 1.62 cfs of 6.21 cfs potential flow) 2=Orifice/Grate (Orifice Controls 1.62 cfs @ 8.26 fps) 3=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) Pond 1P: Surface/Subsurface Detention Inflow Outflow Discarded Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=2.954 ac Peak Elev=149.20' Storage=45,356 cf 20.96 cfs 2.05 cfs 0.43 cfs1.62 cfs Existing Conditions Type III 24-hr 100 Year Rainfall=7.76"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 48HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Pond OS 1P: Offsite Basin Inflow Area = 16.523 ac, 0.00% Impervious, Inflow Depth = 2.41" for 100 Year event Inflow = 24.28 cfs @ 12.48 hrs, Volume= 3.322 af Outflow = 22.91 cfs @ 12.58 hrs, Volume= 3.322 af, Atten= 6%, Lag= 6.2 min Primary = 14.87 cfs @ 12.58 hrs, Volume= 3.153 af Routed to Link POA-1A : Galvin Lane Secondary = 8.04 cfs @ 12.58 hrs, Volume= 0.169 af Routed to Pond 1P : Surface/Subsurface Detention Routing by Stor-Ind method, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Peak Elev= 151.80' @ 12.58 hrs Surf.Area= 5,635 sf Storage= 13,883 cf Plug-Flow detention time= 12.0 min calculated for 3.322 af (100% of inflow) Center-of-Mass det. time= 11.8 min ( 899.9 - 888.1 ) Volume Invert Avail.Storage Storage Description #1 148.00' 21,446 cf Custom Stage Data (Irregular) Listed below (Recalc) Elevation Surf.Area Perim. Inc.Store Cum.Store Wet.Area (feet) (sq-ft) (feet) (cubic-feet) (cubic-feet) (sq-ft) 148.00 1,856 257.0 0 0 1,856 150.00 3,729 332.0 5,477 5,477 5,420 151.00 4,768 354.0 4,238 9,715 6,669 152.00 5,860 373.0 5,305 15,020 7,827 153.00 7,009 392.0 6,426 21,446 9,045 Device Routing Invert Outlet Devices #1 Primary 148.00'18.0" Round Culvert L= 190.0' Ke= 0.500 Inlet / Outlet Invert= 148.00' / 142.00' S= 0.0316 '/' Cc= 0.900 n= 0.010 PVC, smooth interior, Flow Area= 1.77 sf #2 Device 1 148.00'20.0" W x 12.0" H Vert. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 150.00'12.0' long x 1.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 Coef. (English) 2.69 2.72 2.75 2.85 2.98 3.08 3.20 3.28 3.31 3.30 3.31 3.32 #4 Secondary 151.50'20.0' long x 5.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 Coef. (English) 2.34 2.50 2.70 2.68 2.68 2.66 2.65 2.65 2.65 2.65 2.67 2.66 2.68 2.70 2.74 2.79 2.88 Existing Conditions Type III 24-hr 100 Year Rainfall=7.76"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 49HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Primary OutFlow Max=14.86 cfs @ 12.58 hrs HW=151.80' (Free Discharge) 1=Culvert (Inlet Controls 14.86 cfs @ 8.41 fps) 2=Orifice/Grate (Passes < 14.56 cfs potential flow) 3=Broad-Crested Rectangular Weir (Passes < 95.89 cfs potential flow) Secondary OutFlow Max=7.94 cfs @ 12.58 hrs HW=151.80' (Free Discharge) 4=Broad-Crested Rectangular Weir (Weir Controls 7.94 cfs @ 1.32 fps) Pond OS 1P: Offsite Basin Inflow Outflow Primary Secondary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=16.523 ac Peak Elev=151.80' Storage=13,883 cf 24.28 cfs 22.91 cfs 14.87 cfs 8.04 cfs Existing Conditions Type III 24-hr 100 Year Rainfall=7.76"Post-Development Printed 9/23/2024Prepared by {enter your company name here} Page 50HydroCAD® 10.10-7a s/n 04881 © 2021 HydroCAD Software Solutions LLC Summary for Link POA-1A: Galvin Lane Inflow Area = 19.657 ac, 10.60% Impervious, Inflow Depth = 2.44" for 100 Year event Inflow = 16.46 cfs @ 12.60 hrs, Volume= 4.001 af Primary = 16.46 cfs @ 12.60 hrs, Volume= 4.001 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-36.00 hrs, dt= 0.03 hrs Link POA-1A: Galvin Lane Inflow Primary Hydrograph Time (hours) 3635343332313029282726252423222120191817161514131211109876543210Flow (cfs)18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=19.657 ac 16.46 cfs 16.46 cfs Pipe Capacity Analysis Page 1 Name:Horizon View Proj. No.:24029 Design Parameters: Date: 10 Year Storm 80 Montvale Ave Client:Honeycomb Partners Computed by: MAP Stoneham MA 02180 Checked by: RWS ke=0.5 P 781.279.0173 LOCATION AREA Cn Cn x A SUM TIME OF INTENSITY DESIGN CAPACITY DESCRIPTION FROM TO (AC.)Cn x A CONCENTRATION IDF CURVE Q V n PIPE SLOPE Q full V full cfs fps SIZE ft^3/s ft/s To SSIB CB-1 DMH-1 0.32 0.90 0.29 0.29 6.0 5.1 1.47 3.35 0.011 12 0.006 3.21 4.08 CB-2 DMH-1 0.15 0.90 0.14 0.14 6.0 5.1 0.69 3.41 0.011 12 0.012 4.61 5.87 DMH-1 CDS-1 ---0.42 -5.1 2.16 4.51 0.011 12 0.010 4.17 5.31 CDS-1 SSIB ---0.42 -5.1 2.16 3.66 0.011 12 0.005 3.09 3.94 CB-3 DMH-2 0.44 0.90 0.40 0.40 6.0 5.1 2.02 3.59 0.011 12 0.005 3.09 3.94 CB4 DMH-2 0.20 0.90 0.18 0.18 6.0 5.1 0.92 3.32 0.011 12 0.008 3.84 4.88 DMH-2 DMH-3 ---0.58 -5.1 2.94 3.75 0.011 15 0.005 5.34 4.35 CB-5 DMH-3 0.62 0.90 0.56 1.13 6.0 5.1 5.78 4.60 0.011 18 0.005 9.04 5.11 DMH-3 CDS-2 ---1.13 -5.1 5.78 4.73 0.011 18 0.006 9.29 5.26 CB-6 CDS-2 0.18 0.90 0.16 0.16 6.0 5.1 0.83 3.07 0.011 12 0.007 3.60 4.58 CDS-2 SSIB ---1.13 -5.1 5.78 5.27 0.011 18 0.008 10.96 6.20 CB-7 SSIB 0.37 0.90 0.33 0.33 6.0 5.1 1.70 4.54 0.011 12 0.012 4.57 5.82 To ON-SITE DB SSIB SSI-OCS-1 1.69 0.90 1.52 1.52 6.0 5.1 7.76 1.94 0.011 30 0.000 9.69 1.98 SSI-OCS-1 OSDB ---1.52 -5.1 7.76 1.94 0.011 30 0.000 9.69 1.98 SSIB SSI-OCS-2 1.69 0.90 1.52 1.52 6.0 5.1 7.76 1.94 0.011 30 0.000 9.69 1.98 SSI-OCS-2 OSDB ---1.52 -5.1 7.76 1.94 0.011 30 0.000 9.69 1.98 To LS OCS-OFF OS-DMH-1 14.86 9.89 0.011 18 0.020 17.47 9.89 OS-DMH-1 OS-DMH-2 14.86 9.84 0.011 18 0.020 17.38 9.84 OCS-1 OS-DMH-2 1.62 7.42 0.011 18 0.086 36.41 20.60 OS-DMH-2 OS-DMH-3 16.48 11.21 0.011 18 0.026 20.02 11.33 OS-DMH-3 OS-FES1 16.48 10.95 0.011 18 0.024 19.35 10.95 FLOW RATE BASED ON STORMWATER MODEL POND DISCHARGE RATE FLOW RATE BASED ON STORMWATER MODEL POND DISCHARGE RATE 9/25/2024 Storm Drainage Computations FLOW RATE BASED ON STORMWATER MODEL POND DISCHARGE RATE FLOW RATE BASED ON STORMWATER MODEL POND DISCHARGE RATE FLOW RATE BASED ON STORMWATER MODEL POND DISCHARGE RATE Page 2 Name:Horizon View Proj. No.:24029 Design Parameters: Date: 10 Year Storm 80 Montvale Ave Client:Honeycomb Partners Computed by: MAP Stoneham MA 02180 Checked by: RWS ke=0.5 P 781.279.0173 LOCATION AREA Cn Cn x A SUM TIME OF INTENSITY DESIGN CAPACITY DESCRIPTION FROM TO (AC.)Cn x A CONCENTRATION IDF CURVE Q V n PIPE SLOPE Q full V full cfs fps SIZE ft^3/s ft/s 9/25/2024 Storm Drainage Computations Level Spreader Swale Calculations Level Spreader Calculation Continuity Equation Q=VA Q = Weir Discharge Rate (cfs) C = Runoff Coefficient (3.2) H = Height of Water over Weir (ft) L = Length of Level Spreader Required (ft) V = Velocity over Level Spreader (fps) Q =11.1 cfs (From HydroCAD routing data - 100yr 24hr) C =3.2 (Runoff Coefficient) V =2 fps (Max Velocity Allowed over Spreader Swale) H =0.1 ft (Max Height of Water) Q =VA cfs A = Q/V sf A =5.55 sf A =LH sf (Area = Length x Height) L =A / H ft L =55.5 ft @ 2 fps Minimum Required Length APPENDIX B Soil Report by NRCS 16 OLD FORGE ROAD SUITE A ROCKY HILL, CT 06067 860.726.7889 whitestoneassoc.com Office Locations:    NEW JERSEY PENNSYLVANIA MASSACHUSETTS CONNECTICUT FLORIDA NEW HAMPSHIRE NEW YORK August 15, 2024 via email R.J. O’CONNELL & ASSOCIATES, INC. 80 Montvale Avenue Suite 201 Stoneham, Massachusetts 02180 Attention: Mr. Roy W. Smith Vice President Regarding: STORMWATER MANAGEMENT AREA EVALUATION PROPOSED APARTMENT BUILDING 2268 - 2284 CONNECTICUT ROUTE 32 MAP 106, LOTS 34, 35, & 36 MONTVILLE, NEW LONDON COUNTY, CONNECTICUT WHITESTONE PROJECT NO.: GM2422090.000 Dear Mr. Smith: Whitestone Associates, Inc. (Whitestone) is pleased to submit the results of a stormwater management (SWM) area evaluation in support of the proposed development referenced above. Services were provided in general accordance with Whitestone’s May 10, 2024 proposal. Whitestone also issued an August 14, 2024 Report of Geotechnical Investigation for the above-referenced project. 1.0 PROJECT DESCRIPTION 1.1 Site Location & Existing Conditions The 3.36-acre site is located at 2268 - 2284 Connecticut Route 32 (Norwich New London Turnpike) in the Town of Montville, New London County, Connecticut. At the time of Whitestone’s investigation, the subject site was vacant, with brush and mature trees. The site was previously developed with residences and outbuildings, since demolished. Existing fill from this previous development was encountered in several explorations. A buried asphaltic concrete driveway was encountered in one boring. Limited asphalt-paved driveways were noted around the site. Low stone walls and concrete rubble were noted within the western portion of the site. There appears to be a former well within the eastern/central portion of the site. 1.2 Site Geology On the Surficial Materials Map of Connecticut (1992), the site is shown underlain by glacial till. The Bedrock Geologic Map of Connecticut (1985) indicates that the site is primarily underlain by the Proterozoic Z-age Waterford Group, consisting of gneiss with minor amphibolite, and in the northeastern corner by Proterozoic Z-age Hope Valley Alaskite Gneiss, consisting of gneiss, both part of the Eastern Uplands; Avalonian (Continental) Terrane; Avalonian Anticlinorium. R.J. O’Connell & Associates, Inc. SWM Area Evaluation 2268 - 2284 Connecticut Route 32 Montville, Connecticut August 15, 2024 Page 2 Environmental & Geotechnical Engineers & Consultants  1.3 Proposed Construction Based on a March 15, 2010 Conceptual Site Plan prepared by R.J. O’Connell & Associates, Inc. (RJO), the proposed development will include the construction of a three-story apartment building with a footprint of approximately 20,500-square feet and associated pavements, landscaping, and utilities. Stormwater detention basins planned on the western side of the site. 2.0 FIELD & LABORATORY WORK 2.1 Field Exploration Field exploration consisted of excavating eight test pits (identified as TP-1 through TP-8). The test pits subsequently were backfilled to the surface with excavated soils from the investigation after observing soil conditions. The locations of the test pits are shown on the accompanying Test Location Plan included as Figure 1. Records of Subsurface Exploration for the test pits are provided in Appendix A. The subsurface tests were conducted in the presence of a Whitestone engineer who conducted field tests, recorded visual classifications, and collected samples of the various strata encountered. Test locations were surveyed by others. Groundwater was not encountered in the test pits during field operations and prior to backfilling. Seasonal variations, temperature effects, man-made effects, and recent rainfall conditions may influence the levels of the groundwater. The levels will also depend on the permeability of the soils. Groundwater elevations derived from sources other than seasonally observed groundwater monitor wells may not be representative of true groundwater levels. 2.2 Laboratory Testing Laboratory testing was conducted to provide data for a US Department of Agriculture (USDA) textural analysis. The laboratory testing was conducted in general accordance with applicable ASTM standard test methods and included physical/textural testing of representative samples of the natural soils. Quantitative test results are provided in Appendix B. Physical and Textural Analysis: Representative samples were subjected to laboratory testing that included moisture content determinations (ASTM D2216) and washed gradation analyses (ASTM D422). The soil stratum tested was classified by the Unified Soil Classification System (USCS). The results of the laboratory testing are summarized in the following table. PHYSICAL/TEXTURAL ANALYSES SUMMARY Exploration Sample Depth (fbgs) Moisture Content (%) % Passing No. 200 Sieve USCS Classification B-5 S-2 2.0 - 4.0 11.6 20.8 SM B-8 S-3 5.0 - 7.0 3.2 12.1 SM TP-6 S-1 3.5 18.2 44.9 SM TP-7 S-1 3.5 4.6 12.7 SM TP-8 S-1 4.5 9.2 26.2 SM R.J. O’Connell & Associates, Inc. SWM Area Evaluation 2268 - 2284 Connecticut Route 32 Montville, Connecticut August 15, 2024 Page 3 Environmental & Geotechnical Engineers & Consultants  Based on the results of the gradation testing, the United States Department of Agriculture (USDA) textural analysis classifies the glacial till as “sand” and “sandy loam”, which implies USDA Natural Resources Conservation Service (NRCS) Hydrological Soil Group (HSG) “A” or “B”. 2.3 Infiltration Testing Because of the above soil classification (HSG “A” and “B”), infiltration testing was omitted from the scope. A Rawls infiltration rate of 1.02 inches per hour is appropriate for each test pit location. 3.0 SUBSURFACE CONDITIONS The soil conditions encountered within the subsurface tests conducted by Whitestone consisted of the following generalized strata in order of increasing depth. Records of Subsurface Exploration are provided in Appendix A. Surface Cover Materials: The test pits encountered four inches to 30 inches of topsoil at the ground surface, underlain by six inches to 36 inches of subsoil with roots. Glacial Till: Beneath the surface cover materials, the test pits encountered glacial till, consisting of gray to brown, silty sand with gravel (USCS: SM), frequent cobbles and boulders. Where penetrated, the glacial till extended to depths of eight fbgs to 9.5 fbgs. Test pits TP-5 and TP-8 terminated in the glacial till at depths of 10 fbgs and nine fbgs, respectively. Bedrock: Test pits TP-1 through TP-4, TP-6, and TP-7 encountered excavator refusal on bedrock at depths of eight fbgs to 9.5 fbgs. The bedrock was not sampled through rock coring efforts but was inferred by excavator bucket refusal. Rock coring techniques would be required to further characterize the nature and extent of the bedrock. Groundwater: Groundwater was not encountered within the test pits during the exploration. Minor mottling was noted on the sidewalls of test pit TP-6 at a depth of three fbgs. Whitestone does not consider this mottling to be a true indication of an estimated seasonal groundwater high (ESGWH) but is perhaps indicative of a brief high-water event associated with localized perched conditions. Groundwater levels should be expected to fluctuate seasonally and following periods of precipitation. Whitestone appreciates being of continued service to R.J. O’Connell & Associates, Inc. Please do not hesitate to contact us with any questions regarding this letter. Sincerely, WHITESTONE ASSOCIATES, INC. Richard W.M. McLaren, PE Ryan R. Roy, PE Senior Consultant Vice President RWM/th N:\Job Folders\2024\2422090GM\Reports and Submittals\RJO Montville CT GM2422090 SWM 8-15-24 (Rev. 1).docx Enclosures FIGURE 1 Test Location Plan JB-12JB-9JB-5JB-13JB-1JB-8JB-4JB-2JB-6JB-10JB-3JB-11TP-4B-2B-10B-9B-5B-7B-4B-3B-6TP-1TP-2TP-3TP-5B-1TP-6TP-8TP-7B-8JTP-1JTP-3JTP-216 OLD FORGE ROAD, SUITE A, ROCKY HILL, CT 06067 860.726.7889 WHITESTONEASSOC.COMFIGURE:DATE:PROJECT #:SCALE:CLIENT:DESIGNED BY:PROJ. MGR.:PROJECT: DRAWING TITLE:LEGENDPREVIOUS BORING LOCATIONREFERENCESUBJECT PROPERTY BOUNDARYTHIS PLAN IS BASED ON A 7/19/24 TEST PIT & BUILDING CORNERLOCATION EXHIBIT PREPARED BY RJ O'CONNELL & ASSOCIATES, INC.1" = 50'8/12/241RRMRGM2422090.000 TEST LOCATION PLANNOTE: ALL LOCATIONS ARE APPROXIMATE.WHITESTONE An Employee-Owned CompanyR.J. O’CONNELL & ASSOCIATES, INC. PROPOSED APARTMENT BUILDING 2268 - 2284 ROUTE 32 MONTVILLE, NEW LONDON COUNTY, CONNECTICUTTEST PIT LOCATIONBORING LOCATIONPREVIOUS TEST PIT LOCATION APPENDIX A Records of Subsurface Exploration TP-1 of 1 Project: Location: Surface Elevation:±149.9 feet NAVD88 || Termination Depth:9.0 || Proposed Location:Logged By:|-- Contractor:At Completion:|----| Rig Type:|-- Depth (ft.)Type 0.0 5.0 10.0 15.0 3.5 1 Grab 7.5 2 Grab RECORD OF Test Pit No.: SUBSURFACE EXPLORATION Page 1 Date Started:7/22/2024 Water Depth Elevation Cave-In Depth Elevation Proposed Apartment Building WAI Project No.:GM2422090.000 2268 - 2284 Connecticut Route 32, Montville, New London County, Connecticut Client:R.J. O'Connell & Associates, Inc. -- feet bgs Date Completed:7/22/2024 (feet bgs)(ft NAVD88)(feet bgs) Test Method:Visual Observation Caterpillar 314 24 Hours: -- Excavating Method:Midi Excavator CL --At Completion:-- (ft NAVD88) SWM Area JB During: SAMPLE INFORMATION DEPTH STRATA DESCRIPTION OF MATERIALS REMARKS Number (feet)(Classification) No indication of ESGWH TOPSOIL 4" Topsoil SUBSOIL 20" Subsoil, Roots GLACIAL TILL Gray-Brown, Silty Sand with Gravel, Cobbles, Boulders (SM) Test Pit TP-1 Terminated upon Refusal at Depth of 9.0 Feet Below Ground Surface. NOTES: bgs = below ground surface, msl = mean sea level, NA = Not Applicable, NE = Not Encountered, NS = Not Surveyed, P = Perched RECORD OF SUBSURFACE EXPLORATION RJO Apartment Montville CT GM2422090 Test Pit Logs 7-22 and 8-10-24 FOR SWM REPORT 8/15/2024 TP-2 of 1 Project: Location: Surface Elevation:±148.2 feet NAVD88 || Termination Depth:9.0 || Proposed Location:Logged By:|-- Contractor:At Completion:|----| Rig Type:|-- Depth (ft.)Type 0.0 5.0 10.0 15.0 Test Pit TP-2 Terminated upon Refusal at Depth of 9.0 Feet Below Ground Surface. TILL GLACIAL Gray, Silty Sand with Gravel, Cobbles, Boulders (SM) SUBSOIL 30" Subsoil, Roots TOPSOIL 30" Topsoil (feet)(Classification) No indication of ESGWH SAMPLE INFORMATION DEPTH STRATA DESCRIPTION OF MATERIALS REMARKS Number Test Method:Visual Observation Caterpillar 314 24 Hours: -- Excavating Method:Midi Excavator CL --At Completion:-- (ft NAVD88) SWM Area JB During:-- feet bgs Date Completed:7/22/2024 (feet bgs)(ft NAVD88)(feet bgs) RECORD OF Test Pit No.: SUBSURFACE EXPLORATION Page 1 Date Started:7/22/2024 Water Depth Elevation Cave-In Depth Elevation Proposed Apartment Building WAI Project No.:GM2422090.000 2268 - 2284 Connecticut Route 32, Montville, New London County, Connecticut Client:R.J. O'Connell & Associates, Inc. NOTES: bgs = below ground surface, msl = mean sea level, NA = Not Applicable, NE = Not Encountered, NS = Not Surveyed, P = Perched RECORD OF SUBSURFACE EXPLORATION RJO Apartment Montville CT GM2422090 Test Pit Logs 7-22 and 8-10-24 FOR SWM REPORT 8/15/2024 TP-3 of 1 Project: Location: Surface Elevation:±147.1 feet NAVD88 || Termination Depth:8.0 || Proposed Location:Logged By:|-- Contractor:At Completion:|----| Rig Type:|-- Depth (ft.)Type 0.0 5.0 10.0 15.0 5.5 2 Grab Test Pit TP-3 Terminated upon Refusal at Depth of 8.0 Feet Below Ground Surface. GLACIAL TILL Brown, Silty Sand with Gravel, Cobbles, Boulders (SM) SUBSOIL 30" Subsoil, Roots 3 1 Grab TOPSOIL 24" Topsoil (feet)(Classification) No indication of ESGWH SAMPLE INFORMATION DEPTH STRATA DESCRIPTION OF MATERIALS REMARKS Number Test Method:Visual Observation Caterpillar 314 24 Hours: -- Excavating Method:Midi Excavator CL --At Completion:-- (ft NAVD88) SWM Area JB During:-- feet bgs Date Completed:7/22/2024 (feet bgs)(ft NAVD88)(feet bgs) RECORD OF Test Pit No.: SUBSURFACE EXPLORATION Page 1 Date Started:7/22/2024 Water Depth Elevation Cave-In Depth Elevation Proposed Apartment Building WAI Project No.:GM2422090.000 2268 - 2284 Connecticut Route 32, Montville, New London County, Connecticut Client:R.J. O'Connell & Associates, Inc. NOTES: bgs = below ground surface, msl = mean sea level, NA = Not Applicable, NE = Not Encountered, NS = Not Surveyed, P = Perched RECORD OF SUBSURFACE EXPLORATION RJO Apartment Montville CT GM2422090 Test Pit Logs 7-22 and 8-10-24 FOR SWM REPORT 8/15/2024 TP-4 of 1 Project: Location: Surface Elevation:±150.6 feet NAVD88 || Termination Depth:8.0 || Proposed Location:Logged By:|-- Contractor:At Completion:|----| Rig Type:|-- Depth (ft.)Type 0.0 5.0 10.0 15.0 7.5 1 Grab Test Pit TP-4 Terminated upon Refusal at Depth of 8.0 Feet Below Ground Surface. GLACIAL Gray-Brown, Silty Sand with Gravel, Cobbles, Boulders (SM) TILL SUBSOIL 36" Subsoil, Roots TOPSOIL 12" Topsoil (feet)(Classification) No indication of ESGWH SAMPLE INFORMATION DEPTH STRATA DESCRIPTION OF MATERIALS REMARKS Number Test Method:Visual Observation Caterpillar 314 24 Hours: -- Excavating Method:Midi Excavator CL --At Completion:-- (ft NAVD88) SWM Area JB During:-- feet bgs Date Completed:7/22/2024 (feet bgs)(ft NAVD88)(feet bgs) RECORD OF Test Pit No.: SUBSURFACE EXPLORATION Page 1 Date Started:7/22/2024 Water Depth Elevation Cave-In Depth Elevation Proposed Apartment Building WAI Project No.:GM2422090.000 2268 - 2284 Connecticut Route 32, Montville, New London County, Connecticut Client:R.J. O'Connell & Associates, Inc. NOTES: bgs = below ground surface, msl = mean sea level, NA = Not Applicable, NE = Not Encountered, NS = Not Surveyed, P = Perched RECORD OF SUBSURFACE EXPLORATION RJO Apartment Montville CT GM2422090 Test Pit Logs 7-22 and 8-10-24 FOR SWM REPORT 8/15/2024 TP-5 of 1 Project: Location: Surface Elevation:±146.3 feet NAVD88 || Termination Depth:10.0 || Proposed Location:Logged By:|-- Contractor:At Completion:|----| Rig Type:|-- Depth (ft.)Type 0.0 5.0 10.0 15.0 Test Pit TP-5 Terminated at Depth of 10.0 Feet Below Ground Surface. GLACIAL TILL Brown to Gray-Brown, Silty Sand with Gravel, Cobbles, Boulders (SM) 5.5 1 Grab SUBSOIL 30" Subsoil, Roots TOPSOIL 24" Topsoil (feet)(Classification) No indication of ESGWH SAMPLE INFORMATION DEPTH STRATA DESCRIPTION OF MATERIALS REMARKS Number Test Method:Visual Observation Caterpillar 314 24 Hours: -- Excavating Method:Midi Excavator CL --At Completion:-- (ft NAVD88) SWM Area JB During:-- feet bgs Date Completed:7/22/2024 (feet bgs)(ft NAVD88)(feet bgs) RECORD OF Test Pit No.: SUBSURFACE EXPLORATION Page 1 Date Started:7/22/2024 Water Depth Elevation Cave-In Depth Elevation Proposed Apartment Building WAI Project No.:GM2422090.000 2268 - 2284 Connecticut Route 32, Montville, New London County, Connecticut Client:R.J. O'Connell & Associates, Inc. NOTES: bgs = below ground surface, msl = mean sea level, NA = Not Applicable, NE = Not Encountered, NS = Not Surveyed, P = Perched RECORD OF SUBSURFACE EXPLORATION RJO Apartment Montville CT GM2422090 Test Pit Logs 7-22 and 8-10-24 FOR SWM REPORT 8/15/2024 TP-6 of 1 Project: Location: Surface Elevation:±150.0 feet NAVD88 || Termination Depth:9.5 || Proposed Location:Logged By:|-- Contractor:At Completion:|----| Rig Type:|-- Depth (ft.)Type 0.0 5.0 10.0 15.0 RECORD OF Test Pit No.: SUBSURFACE EXPLORATION Page 1 Date Started:8/10/2024 Water Depth Elevation Cave-In Depth Elevation Proposed Apartment Building WAI Project No.:GM2422090.000 2268 - 2284 Connecticut Route 32, Montville, New London County, Connecticut Client:R.J. O'Connell & Associates, Inc. (ft NAVD88) SWM Area JB During:-- feet bgs Date Completed:8/10/2024 (feet bgs)(ft NAVD88)(feet bgs) Test Method:Visual Observation Caterpillar 430 24 Hours: -- Excavating Method:Backhoe CL --At Completion:-- (feet)(Classification) No indication of ESGWH SAMPLE INFORMATION DEPTH STRATA DESCRIPTION OF MATERIALS REMARKS Number SUBSOIL 6" Subsoil, Roots Minor mottling @ 3 fbgs GLACIAL Brown, Silty Sand with Gravel, Cobbles, Boulders (SM) TILL Test Pit TP-6 Terminated upon Refusal at Depth of 9.5 Feet Below Ground Surface. 3.5 1 Grab TOPSOIL 12" Topsoil NOTES: bgs = below ground surface, msl = mean sea level, NA = Not Applicable, NE = Not Encountered, NS = Not Surveyed, P = Perched RECORD OF SUBSURFACE EXPLORATION RJO Apartment Montville CT GM2422090 Test Pit Logs 7-22 and 8-10-24 FOR SWM REPORT 8/15/2024 TP-7 of 1 Project: Location: Surface Elevation:±146.0 feet NAVD88 || Termination Depth:9.5 || Proposed Location:Logged By:|-- Contractor:At Completion:|----| Rig Type:|-- Depth (ft.)Type 0.0 5.0 10.0 15.0 RECORD OF Test Pit No.: SUBSURFACE EXPLORATION Page 1 Date Started:8/10/2024 Water Depth Elevation Cave-In Depth Elevation Proposed Apartment Building WAI Project No.:GM2422090.000 2268 - 2284 Connecticut Route 32, Montville, New London County, Connecticut Client:R.J. O'Connell & Associates, Inc. (ft NAVD88) SWM Area JB During:-- feet bgs Date Completed:8/10/2024 (feet bgs)(ft NAVD88)(feet bgs) Test Method:Visual Observation Caterpillar 430 24 Hours: -- Excavating Method:Backhoe CL --At Completion:-- SAMPLE INFORMATION DEPTH STRATA DESCRIPTION OF MATERIALS REMARKS Number TOPSOIL 24" Topsoil (feet)(Classification) No indication of ESGWH SUBSOIL 6" Subsoil, Roots 3.5 1 Grab TILL GLACIAL Brown, Silty Sand with Gravel, Cobbles, Boulders (SM) Test Pit TP-7 Terminated upon Refusal at Depth of 9.5 Feet Below Ground Surface. NOTES: bgs = below ground surface, msl = mean sea level, NA = Not Applicable, NE = Not Encountered, NS = Not Surveyed, P = Perched RECORD OF SUBSURFACE EXPLORATION RJO Apartment Montville CT GM2422090 Test Pit Logs 7-22 and 8-10-24 FOR SWM REPORT 8/15/2024 TP-8 of 1 Project: Location: Surface Elevation:±148.0 feet NAVD88 || Termination Depth:9.0 || Proposed Location:Logged By:|-- Contractor:At Completion:|----| Rig Type:|-- Depth (ft.)Type 0.0 5.0 10.0 15.0 RECORD OF Test Pit No.: SUBSURFACE EXPLORATION Page 1 Date Started:8/10/2024 Water Depth Elevation Cave-In Depth Elevation Proposed Apartment Building WAI Project No.:GM2422090.000 2268 - 2284 Connecticut Route 32, Montville, New London County, Connecticut Client:R.J. O'Connell & Associates, Inc. (ft NAVD88) SWM Area JB During:-- feet bgs Date Completed:8/10/2024 (feet bgs)(ft NAVD88)(feet bgs) Test Method:Visual Observation Caterpillar 430 24 Hours: -- Excavating Method:Backhoe CL --At Completion:-- SAMPLE INFORMATION DEPTH STRATA DESCRIPTION OF MATERIALS REMARKS Number TOPSOIL 12" Topsoil (feet)(Classification) No indication of ESGWH SUBSOIL 6" Subsoil, Roots GLACIAL 4.5 1 Grab TILL Brown, Silty Sand with Gravel, Cobbles, Boulders (SM) Test Pit TP-8 Terminated upon Refusal at Depth of 9.0 Feet Below Ground Surface. NOTES: bgs = below ground surface, msl = mean sea level, NA = Not Applicable, NE = Not Encountered, NS = Not Surveyed, P = Perched RECORD OF SUBSURFACE EXPLORATION RJO Apartment Montville CT GM2422090 Test Pit Logs 7-22 and 8-10-24 FOR SWM REPORT 8/15/2024 APPENDIX B Laboratory Test Results MM RWM PL= LL= PI= D90= D85= D60=D50= D30= D15=D10= Cu= Cc= USCS= AASHTO= *PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.0010.010.11101006 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200 MM RWM PL= LL= PI= D90= D85= D60=D50= D30= D15=D10= Cu= Cc= USCS= AASHTO= *PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.0010.010.11101006 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200 MM RWM PL= LL= PI= D90= D85= D60=D50= D30= D15=D10= Cu= Cc= USCS= AASHTO= *PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.0010.010.11101006 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200 MM RWM PL= LL= PI= D90= D85= D60=D50= D30= D15=D10= Cu= Cc= USCS= AASHTO= *PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.0010.010.11101006 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200 MM RWM PL= LL= PI= D90= D85= D60=D50= D30= D15=D10= Cu= Cc= USCS= AASHTO= *PERCENT FINER0 10 20 30 40 50 60 70 80 90 100 GRAIN SIZE - mm. 0.0010.010.11101006 in.3 in.2 in.1½ in.1 in.¾ in.½ in.3/8 in.#4#10#20#30#40#60#100#140#200 APPENDIX C Supplemental Information (USCS, Terms & Symbols) 16 OLD FORGE ROAD SUITE A ROCKY HILL, CT 06067 860.726.7889 whitestoneassoc.com Office Locations: NEW JERSEY PENNSYLVANIA MASSACHUSETTS CONNECTICUT FLORIDA NEW HAMPSHIRE NEW YORK UNIFIED SOIL CLASSIFICATION SYSTEM SOIL CLASSIFICATION CHART MAJOR DIVISIONS LETTER SYMBOL TYPICAL DESCRIPTIONS COARSE GRAINED SOILS MORE THAN 50% OF MATERIAL IS LARGER THAN NO. 200 SIEVE SIZE GRAVEL AND GRAVELLY SOILS MORE THAN 50% OF COARSE FRACTION RETAINED ON NO. 4 SIEVE CLEAN GRAVELS (LITTLE OR NO FINES) GW WELL-GRADED GRAVELS, GRAVEL-SAND MIXTURES, LITTLE OR NO FINES GP POORLY-GRADED GRAVELS, GRAVEL-SAND MIXTURES, LITTLE OR NO FINES GRAVELS WITH FINES (APPRECIABLE AMOUNT OF FINES) GM SILTY GRAVELS, GRAVEL-SAND-SILT MIXTURES GC CLAYEY GRAVELS, GRAVEL-SAND-CLAY MIXTURES SAND AND SANDY SOILS MORE THAN 50% OF COARSE FRACTION PASSING NO. 4 SIEVE CLEAN SAND (LITTLE OR NO FINES) SW WELL-GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO FINES SP POORLY-GRADED SANDS, GRAVELLY SANDS, LITTLE OR NO FINES SANDS WITH FINES (APPRECIABLE AMOUNT OF FINES) SM SILTY SANDS, SAND-SILT MIXTURES SC CLAYEY SANDS, SAND-CLAY MIXTURES FINE GRAINED SOILS MORE THAN 50% OF MATERIAL IS SMALLER THAN NO. 200 SIEVE SIZE SILTS AND CLAYS LIQUID LIMITS LESS THAN 50 ML INORGANIC SILTS AND VERY FINE SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYEY SILTS WITH SLIGHT PLASTICITY CL INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS OL ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY SILTS AND CLAYS LIQUID LIMITS GREATER THAN 50 MH INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SAND OR SILTY SOILS CH INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTS HIGHLY ORGANIC SOILS PT PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC CONTENTS NOTE: DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS FOR SAMPLES WITH 5% TO 12% FINES GRADATION* COMPACTNESS* Sand and/or Gravel CONSISTENCY* Clay and/or Silt % FINER BY WEIGHT RELATIVE DENSITY RANGE OF SHEARING STRENGTH IN POUNDS PER SQUARE FOOT TRACE........... 1% TO 10% LITTLE.......... 10% TO 20% SOME............ 20% TO 35% AND............... 35% TO 50% LOOSE. .................. 0% TO 40% MEDIUM DENSE.... 40% TO 70% DENSE................... 70% TO 90% VERY DENSE........ 90% TO 100% VERY SOFT....... LESS THAN 250 SOFT.................... ..... 250 TO 500 MEDIUM................... 500 TO 1000 STIFF..................... 1000 TO 2000 VERY STIFF.......... 2000 TO 4000 HARD...... GREATER THAN 4000 * VALUES ARE FROM LABORATORY OR FIELD TEST DATA, WHERE APPLICABLE. WHEN NO TESTING WAS PERFORMED, VALUES ARE ESTIMATED. L:\Geotechnical Forms and References\Reports\USCSTRMSSYM CT.docx 16 OLD FORGE ROAD SUITE A ROCKY HILL, CT 06067 860.726.7889 whitestoneassoc.com Office Locations: NEW JERSEY PENNSYLVANIA MASSACHUSETTS CONNECTICUT FLORIDA NEW HAMPSHIRE NEW YORK GEOTECHNICAL TERMS AND SYMBOLS SAMPLE IDENTIFICATION The Unified Soil Classification System is used to identify the soil unless otherwise noted. SOIL PROPERTY SYMBOLS N: Standard Penetration Value: Blows per ft. of a 140 lb. hammer falling 30" on a 2" O.D. split-spoon. Qu: Unconfined compressive strength, TSF. Qp: Penetrometer value, unconfined compressive strength, TSF. Mc: Moisture content, %. LL: Liquid limit, %. PI: Plasticity index, %. δd: Natural dry density, PCF. ▾: Apparent groundwater level at time noted after completion of boring. DRILLING AND SAMPLING SYMBOLS NE: Not Encountered (Groundwater was not encountered). SS: Split-Spoon - 1 ⅜” I.D., 2" O.D., except where noted. ST: Shelby Tube - 3” O.D., except where noted. AU: Auger Sample. OB: Diamond Bit. CB: Carbide Bit WS: Washed Sample. RELATIVE DENSITY AND CONSISTENCY CLASSIFICATION Term (Non-Cohesive Soils) Standard Penetration Resistance Very Loose 0-4 Loose 4-10 Medium Dense 10-30 Dense 30-50 Very Dense Over 50 Term (Cohesive Soils) Qu (TSF) Very Soft 0 - 0.25 Soft 0.25 - 0.50 Firm (Medium) 0.50 - 1.00 Stiff 1.00 - 2.00 Very Stiff 2.00 - 4.00 Hard 4.00+ PARTICLE SIZE Boulders 8 in.+ Coarse Sand 5mm-0.6mm Silt 0.074mm-0.005mm Cobbles 8 in.-3 in. Medium Sand 0.6mm-0.2mm Clay -0.005mm Gravel 3 in.-5mm Fine Sand 0.2mm-0.074mm L:\Geotechnical Forms and References\Reports\USCSTRMSSYM CT.docx APPENDIX C Stormwater Pollution Control Plan (SWPCP) To be submitted prior to construction Stormwater Pollution Control Plan (SWPCP) Residential Development 2268-2284 Connecticut Route 32 Montville, CT 06353 Prepared for: Honeycomb Real Estate Partners 20 Avon Meadow Lane Montville, CT 06001 Prepared by: RJOC R.J. O’Connell & Associates, Inc. 80 Montvale Ave, Suite 201 Stoneham, MA 02180 Date: September 25, 2024 STORMWATER POLLUTION CONTROL PLAN SWPCP Horizon View Montville, CT State Project No. TBD EzFile No. TBD Connecticut Department of Transportation October 2024 This Stormwater Pollution Control Plan (SWPCP) is prepared to comply with the requirements for the General Permit for Stormwater Discharges from Construction Activities and the 2024 Connecticut Guidelines for Soil Erosion and Sediment Control (2024 E&S Guidelines). 2 Stormwater Pollution Control Plan Connecticut Department of Transportation Table of Contents Development & Contents of Plan .................................................................................................4 Site Description ..............................................................................................................................4 Site Description ................................................................................................................................ 4 Estimated Disturbed Area ................................................................................................................ 5 Estimated Runoff Coefficient .......................................................................................................... 5 Receiving Waters ............................................................................................................................. 5 Extent of Wetlands on Site .............................................................................................................. 5 Construction Sequencing ..............................................................................................................6 Control Measures ...........................................................................................................................7 Erosion and Sedimentation Controls ............................................................................................... 7 Soil Stabilization and Protection ...................................................................................................... 8 Temporary Stabilization Practices ................................................................................................... 9 Permanent Stabilization Practices .................................................................................................. 10 Structural Measures ....................................................................................................................... 11 Maintenance ................................................................................................................................... 12 Dewatering Wastewaters .............................................................................................................12 Dewatering Guidelines................................................................................................................... 12 Post-Construction Stormwater Management............................................................................13 Post-Construction Guidelines ........................................................................................................ 13 Post Construction Performance Standards and Control Measure .................................................. 13 Redevelopment: ............................................................................................................................. 13 Other Development: ....................................................................................................................... 16 Runoff Reduction and LID Practices ............................................................................................. 16 Suspended Solids and Floatable Removal ..................................................................................... 16 Velocity Dissipation: ..................................................................................................................... 16 Other Controls (Non-Structural)................................................................................................17 Waste Disposal .............................................................................................................................. 17 Washout Areas ............................................................................................................................... 17 Anti-tracking Pads and Dust Control ............................................................................................. 17 Maintaining and Storing Vehicles and Equipment- Storage of Chemicals & Petroleum Products ............................................................................................................................ 18 Cold Water Stream Habitat ............................................................................................................ 18 3 Inspections ....................................................................................................................................19 Plan Implementation Inspections ................................................................................................... 19 Post-Construction Inspection ......................................................................................................... 20 Final Stabilization Inspection ........................................................................................................ 20 Keeping Plans Current ................................................................................................................21 Revisions to Stormwater Pollution Control Plans .......................................................................... 21 Contractors ...................................................................................................................................22 Certification Statement .................................................................................................................. 22 List of applicable Figures / Plans: ..............................................................................................24 Appendix A – Figures .................................................................................................................... 24 Appendix B – Plan Sheets.............................................................................................................. 24 Appendix C- Connecticut DEEP General Permit for the Discharge of Stormwater and Dewatering Wastewaters from Construction Activities .................................................... 24 Appendix D- CTDOT MS4 Project Design Maximum Extent Practicable Worksheet ................. 24 Appendix E- Construction Site Environmental Inspection Report (CSEIR) ................................. 24 Appendix F – Notice of Termination Form ................................................................................... 24 4 Development & Contents of Plan The Plan shall consist of site plan drawings and a narrative. The Plan shall be prepared in accordance with sound engineering practices, and shall be consistent with the 2024 Connecticut Guidelines for Soil Erosion and Sediment Control (2024 E&S Guidelines), the 2024 Connecticut Stormwater Quality Manual (2024 SWQ Manual), and any applicable requirements of this general permit. Site Description Site Description The proposed project site, referred herein as the “Site”, is located at 2268-2248 Norwich-New London Turnpike (Route 32) in Montville, CT. The Site totals approximately 3.4 acres in area, located in the Commercial 1 (C-1) district and the Route 32 Overlay District (OZ) and is bound by residential properties to the north and west, Route 32 to the east, and Shantok Motors commercial property to the south. The existing Site is currently an undeveloped open space area. The purpose of this project is to construct a new four-story, 60,000 sf, 57-unit residential building with an approximate 15,000 sf footprint. Substantial new landscaping along the perimeter and within the development is proposed, along with a stormwater management system providing water quality treatment and peak flow mitigation. • Stormwater from the Site flows off the property in one location and onto Meadow Lane. Runoff from the Site flows into Shantok Brook. Shantok Brook is not identified as an impaired water body per the 2022 State of Connecticut Integrated Water Quality Report. o 2022 Integrated Water Quality Report – List of Impaired Waters for CT • The project is not within an Aquifer Protection Area (APA) per the online Connecticut Aquifer Protection Areas map. The project is not located within a public water supply watershed per the online DPH Connecticut Public Water Supply Map. o Aquifer Protection Area Interactive Map o Public Water Supply Map (ct.gov) • The outfall from the project does not discharge to a river within the National Wild and Scenic Rivers System Connecticut per the online National Wild and Scenic Rivers System mapping tool. o National Wild & Scenic River System • There are no endangered or threatened species and critical habitats on or near the project area per the Natural Diversity Data Base Areas – Montville, CT Map. 5 Estimated Disturbed Area The total area for this project site is 3.4 acres. Of this area, 3.4 acres will be disturbed by construction activities. Total project area: 3.4 acres Construction site area to be disturbed: 3.4 acres Percentage impervious (pre-development): 0% Percentage impervious (post-development): 61% Effective impervious cover (pre-development) = 0% Effective impervious cover (post-development) = 62% Estimated Runoff Coefficient As depicted in the calculations below, the runoff coefficient for pre- and post-construction is 0.77 and 0.75 (respectively). The runoff coefficient assumed for pavement is 0.9 and for gravel roads is 0.7. For the pervious areas, a coefficient of 0.3 was assumed. Pre-Construction _________(0 ac. x 0.9)+(3.4 ac. x 0.3)_______ = 0.30 0 ac. + 3.4 ac. Pre-Construction _________(2.1 ac. x 0.9)+(1.3 ac. x 0.3)_______ = 0.67 2.1 ac. + 1.3 ac. Receiving Waters Stormwater from the Site flows off the property at one location. Runoff from the Site flows onto Meadow Lane and eventually discharges to Shantok Brook and the Thames River. The Shantok Brook is not identified as an impaired water body per the 2022 State of Connecticut Integrated Water Quality Report. Extent of Wetlands on Site There is one small wetland located at the north property line of the Site. The Site is located outside the 100-year flood zone according to the Federal Emergency management Agency (FEMA) FIRM panel 357 of 554 on map number 09011C0351G last revised July 18, 2011. 6 Construction Sequencing The proposed project will be constructed in one phase. Construction is anticipated to take one year from the completion of permitting. The contractor will be responsible for implementing the following erosion and sediment controls and storm water management control measures. The contractor shall comply with the Connecticut Department of Energy & Environmental Protection (DEEP) 2024 Stormwater Quality Manual and the most recent edition of the Connecticut Erosion and Sediment Guidelines. The contractor may designate these tasks to certain subcontractors as he sees fit, but the ultimate responsibility for implementing these controls and ensuring their proper functioning remains with the contractor. The order of activities will be as follows: 1. Install perimeter straw wattles in the locations shown on DWG. C-1 titled “Demolition and Erosion Control Plan”. Straw wattles to be installed per detail shown on detail sheets. 2. Install inlet/outlet protection at the locations of all existing grate inlets, curb inlets and at the ends of all exposed storm water drainage pipes. 3. Begin termination of existing utility services in accordance with the requirements of the utility company having authority. 4. Commence clearing and grubbing activities. 5. Excavate temporary sediment basin and temporary drainage swale per the C-1 plan and as needed to collect any silt laden runoff. 6. The temporary sediment basin and temporary drainage swale shown on the plan depict one point in time during earthwork construction. The temporary basins as shown are sized to hold a volume of 134 cy/ac based on contributing area. Catchment areas to sediment traps shall be kept as small as possible. Installation of the infiltration system will be kept as small as possible. 7. Installation of the infiltration system will commence once temporary drainage swales and sediment basins are in place. 8. Commence site grading activities (rough grade site). During grading activities perform erosion and sediment control inspections as required this Stormwater Pollution Control Plan. 9. Fill slopes shall be compacted and stabilized with vegetation and erosion control blankets as quickly as possible during the initial site earthwork. 10. At all times during grading activities, verify stability of perimeter controls and repair where necessary. Clean and re-install all inlet and outlet protection. Cover stockpiles to minimize erosion by wind or rainfall. Complete final sweeping of all existing paved surfaces to remove any remaining sediment. 11. Inspect the entire site to verify that no areas remain that are susceptible to allowing sediment and/or hazardous materials to be discharged from the project Site. 12. Disturbed areas of the Site where construction activity has, or will, cease for more than 7 days shall be temporarily stabilized. 13. Install site utilities. Inlet protection must be installed at all existing and new drain inlets. Place rip-rap and outlet protection at all drain outlets at locations shown on the plans. 14. Finalize pavement and building subgrade preparation. 15. Remove inlet protection around inlets and manholes no more than 48 hours prior to placing stabilized base course. 7 16. Install and compact pavement gravel. 17. Install binder and finish course pavement. 18. Install silt bags in catch basins until the site is vegetated and stabilized. 19. Fine grade landscape areas and install landscape plantings. 20. Install traffic control signage and parking lot striping. 21. Complete outstanding punch list items and perform final clean-up activities. 22. Remove and dispose of all accumulated sands and sediment to design grades, stabilize and revegetate disturbed areas. 23. Remove perimeter controls after paving operations are complete and all disturbed areas are stabilized, only upon approval of the Town of Waterford. 24. Clean all stormwater structures and devices that collected and conveyed stormwater from the construction area. Control Measures _____________________________________________________________________________ This section describes the minimum measures required to control soil erosion during and after construction of the proposed sitework. The soil erosion and sediment control measures depicted herein are designed in accordance with a document entitled “Connecticut Guidelines for Soil Erosion and Sediment Control” published by the Connecticut Council on Soil and Water Conservation in 2024. The contractor may be required to implement additional measures to prevent site erosion and sedimentation of downstream waterways. For those areas for which construction activity will be temporarily suspended for a period of greater than 14 days, temporary stabilization measures shall be implemented within 3 days of such suspension of activity. For all areas, permanent stabilization shall be implemented within 30 days of disturbance: Erosion and Sedimentation Controls The Department of Transportation (STET) will have a Qualified Inspector assigned to the project to oversee the Contractor’s operations and to ensure compliance with the provisions of the Contract. Further Department oversight is provided by the Eastern District Environmental Coordinator and the Office of Environmental Planning. The following timelines will be followed for the proposed construction activities: • The Contractor shall stabilize disturbed areas with temporary or permanent measures as quickly as possible after the land is disturbed. Requirements for soil stabilization are detailed in Form 818 Section 1.10, Environmental Compliance. • Areas that remain disturbed but inactive for at least 30 days shall receive temporary seeding or soil protection within seven (7) days. • Areas that will be disturbed past the planting season will be covered with a long-term, non- vegetative stabilization method that will provide protection through the winter. 8 • If construction activities are completed to final grade, permanent seeding shall take place within seven (7) days. (Review Chapter 5 of the 2022 E&S Guidelines) The following note (below) appears on the project Construction Plans; Department projects are required to have Preconstruction Meetings with the Contractor. The Contractor is required to review and understand the Contract Plans and Specifications and to develop an E&S Plan for review and approval by the Engineer. In the review of the Contractor’s E&S plan at all disturbed locations for compliance with the Stormwater Permit requirements for a double row of sediment control barriers. Double Row of Erosion and Sediment Control Barriers (SCS) • Additional erosion control barriers (double row of SCS) may be required within the project area. Factors to be reviewed by the Engineer include but are not limited to: the contributing disturbed area, drainage area, slope, length of slope, and flow conditions to maintain sheet flow. If determined necessary, the Engineer will direct the Contractor to install and maintain additional rows of erosion control barrier (or equivalent). Soil Stabilization and Protection The project erosion and sediment control monitor shall supervise the layout of sediment and erosion control measures to ensure maximum protection of existing native trees and shrubs. Erosion and sediment control measures shall be installed prior to any fill being placed and shall be modified as required during earthwork operations to control and divert surface runoff from fill slopes and exposed soil surfaces. The erosion and sediment control measures shall include silt fences and staked straw wattles at bottom of fill slopes. erosion control blankets shall be placed on completed slopes steeper than 3:1 as soon as possible. When necessary, seeding with temporary grasses may be required. use berms and temporary drainage swales to divert runoff from slopes prior to final stabilization. Bring all excavated, filled, or disturbed areas to final grade as soon as possible and stabilize areas with loam, seed and mulch immediately. Keep erosion control measures in place until the site is stabilized with pavement and/or vegetation. Reverse Slope Benches A reverse slope bench is required for any slope steeper than 3:1 (horizontal: vertical) that exceeds 15 feet vertically, except when engineered slope stabilization structures or measures are included or a detailed soil mechanics analysis has been conducted to verify stability. Engineered analyses and measures must be designed by a Connecticut licensed Professional Engineer with experience in geotechnical engineering or soil mechanics. Reverse Slope Benches have not been incorporated into the project since there are no slopes steeper than 3H:1V that exceed 15’ tall. Therefore, there is no need to lessen the erosive potential of surface water and subsequent rilling and rutting. 9 Temporary Stabilization Practices Temporary grass cover: Provide temporary grass cover where indicated on the plans or where temporary land grading will be unaltered for more than one month but less than 12 months. The contractor shall loosen the soil to a depth of two inches before seeding. If existing soil is not capable of growing grass, the contractor shall spread at least two inches of topsoil over the loosened surface. If seeding commences during the summer or early autumn, annual or perennial rye grass seed shall be used. If seeding commences in spring or late autumn, winter rye grass seed shall be used. Seeding rates shall be 5 lbs./1000 s.f. Hay mulch shall be spread at the rate of 100 lbs/1000 s.f. The contractor shall irrigate the grass until an acceptable stand of grass is established. Stockpiling or storage of excavated materials: Completely surround all temporary (2-4 weeks) material stockpiles with silt fence to prevent transportation of sediment. Seed stockpiles what will remain for a longer duration with a quick growing rye grass. Fabric slope protection: Install fabric slope protection on slopes steeper than 3:1. The contractor shall select a fabric from the Connecticut department of transportation's approved product list. Curlex erosion control matting by American Excelsior company or approved equal. The contractor will submit a filter fabric shop drawing for engineer and municipality review and approval. The fabric shall meet the requirements of class 1 type c slope protection. The fabric shall be installed in accordance with the manufacturer's instructions and guidelines. The contractor shall maintain the fabric until a stand of grass, acceptable to the engineer, is established. Temporary mulch: Mulch all disturbed areas with hay or straw at the rate of 2 tons per acre. Spread mulch by hand or mulch blower to provide a uniform distribution. Anchor the mulch by tracking with tracked construction equipment so cleat marks are parallel to the contour. Mulch nettings, applied in accordance with the manufacturer's recommendations, may be used as an alternate to tracking. Restore any areas where mulch is washed away or blown away by the wind. This activity shall be used to stabilize areas where construction is suspended during the winter months. Once the appropriate dates for seeding are reached, the contractor shall complete the seeding operations. Dust control: Take precautions to prevent dust from becoming a nuisance to abutting property owners and streets. Broom off pavements adjoining the excavation on a daily basis. Cover and/or keep all earth stockpiles moist at all times. Use calcium chloride to control dust over certain areas of the site, as directed by the engineer or shown on the plans, calcium chloride shall conform to ASTM d-98, type I. The contractor shall maintain and inspect, on a daily basis, the adequacy of dust control measures and correct any deficiencies immediately. Tree protection: The contractor shall provide snow fencing, board fencing, or rope fencing around trees or groups of trees that are to remain, to protect them against damage. The contractor shall be responsible for selecting and installing the protection measures most appropriate for the conditions present. 10 The contractor shall repair and/or replace tree protection measures immediately if damaged during construction. Stabilization practices shall be implemented after completion, as final grades are reached, within seven (7) days. Temporary seeding shall be spread over any disturbed areas which will remain inactive for at least 30 days. Areas to remain disturbed through winter shall be protected with non-vegetative stabilization measures. The Contractor must provide an Erosion and Sedimentation Control plan for each winter season during construction operations. The Contractor may elect to utilize other controls in conformance with the 2024 E&S Guidelines, as approved by the Qualified Inspector. The Contractor will be required to provide the necessary details for any erosion controls not specifically called for on the project plans. During construction, all areas disturbed by the construction activity that have not been stabilized, structural control measures, and locations where vehicles enter or exit the site shall be inspected at least once a week and within 24 hours of the end of a storm that generates a discharge. For storms that end on a weekend, holiday, or other time in which normal working hours will not commence within 24 hours, an inspection is required within 24 hours following any storm in which 0.1 inches or greater of rain occurs. For lesser storms, inspection shall occur immediately upon the start of subsequent normal working hours. Permanent Stabilization Practices During construction, the following methods of permanent stabilization shall be installed: • Topsoiling: In conjunction with permanent seeding, once final grades have been established, topsoil shall be applied to provide a suitable growth medium for vegetation. • Permanent Seeding: Once soils have been brought to final grade; permanent seeding shall be used to stabilize the soil with a vegetative cover. Disturbed areas below the wetland limit shall be seeded with the appropriate seed mix. Once the site has achieved final stabilization for at least one full growing season (April – October) in the year following the end of construction, the Contractor shall have the site inspected by a Qualified Inspector to confirm such stabilization is maintained. The Qualified Inspector shall indicate compliance with this requirement on the Notice of Termination form. • Landscaping: Wood chip mulch shall be placed around the plants. Plantings (trees, shrubs, etc.) and permanent seeding may be established together. Wood chip mulch shall NOT be utilized in wetland areas. All new embankments and unpaved areas that are graded or disturbed by construction will receive erosion control matting, topsoil and/or turf establishment. The Contractor may use other permanent stabilization practices approved by the Qualified Inspector and in conformance with the 2024 E&S Guidelines. 11 Structural Measures Temporary structural measures: Catch basin protection, filter fabric and stone filter: Use filter fabric and stone filter for protection of catch basins in a low point as shown and detailed on DWG. C-1 and C-5. Firmly stake filter fabric into the pavement base material. Wrap the entire grate with Mirafi 140n filter fabric or approved equal. Remove sediment from around the inlet protection once levels reach 1/4 the effective height. Replace the inlet protection immediately if they are damaged or deteriorated. The fabric shall be replaced immediately if its permeability is impeded by sediment. Catch basin protection, straw wattle check dams, type 5: Use straw wattle check dams for protection of catch basins in a swale. Place staked barriers in the swale in at least two locations upstream of the basin as shown on the plans and details. Monitor the barriers to ensure that runoff either filters through the barrier or goes over the top. Do not allow runoff to bypass the side of the barrier. Remove the sediment when it reaches 1/4 of the height of the barrier. Temporary sediment trap: Install temporary sediment trap in the locations shown on the plans. Construct the trap to the length, width, and depth shown on the plans. Inspect the sediment trap at least once per week and within 24 hours of the end of a storm with a rainfall amount of 0.5 inches or greater. Remove sediment once levels reach 50 percent of the trap's wet storage volume. Backfill the temporary sediment trap only after the site has been stabilized in a fashion that provides adequate sediment control through permanent devices prior to stormwater reaching the infiltration basin. Temporary swales: If runoff becomes channelized, install temporary swales and direct runoff to a temporary sediment trap. Modify and install additional swales as required during construction to direct runoff from fill slopes and exposed soil surfaces toward temporary sediment traps. Permanent structural measures: Land grading: Proposed grades are shown in detail on civil drawing C-2. Bring all excavated, filled, or disturbed areas to final grade as soon as possible and stabilize areas with loam, seed and mulch immediately. Keep erosion control measures in place until the site is stabilized with pavement and/or vegetation. Infiltration system: An infiltration system is required, as shown on the plans and details, to reduce the peak rate of runoff leaving the site. Construct the infiltration system according to the plans and details. Minimize the amount of sediment flowing into the underground system by temporarily capping the inlet pipe to the system until final catch basins and pavement courses have been installed. Additionally, install silt sacks or approved equivalent until construction is completed, in order to minimize sediment entering the infiltration chamber system. Following construction and site stabilization, the contractor shall remove sediment as required. 12 Maintenance The narrative shall include the procedures to maintain, in good and effective operating conditions, all erosion and sediment control measures, including vegetation, and all other protective measures identified in the Plan. All construction activities and related activities shall conform to the requirements of Section 1.10 "Environmental Compliance" of Form 818, the Department's Standard Specifications for Roads, Bridges, Facilities, and Incidental Construction. In general, all construction activities shall proceed in such a manner so as not to pollute any wetlands, watercourses, water body, and conduit carrying stormwater. The Contractor shall limit, in so far as possible, the surface area of earthen materials exposed by construction activity and immediately provide temporary and permanent pollution control to prevent soil erosion and contamination on the site. Water pollution control provisions and Required Best Management Practices per Section 1.10, Environmental Compliance of the Standard Specifications shall be administered during construction. Control measures shall be inspected and maintained in accordance with the 2024 E&S Guidelines and as directed by the Qualified Inspector . Dewatering Wastewaters Dewatering Guidelines When dewatering is necessary, pumps used shall not be allowed to discharge directly into a wetland, watercourse, or stormwater drainage system. Prior to any dewatering, the Contractor must prepare a written proposal for specific methods and devices to be used, including, but not limited to, the pumping of water into a temporary sedimentation basin, providing surge protection at the inlet or outlet of pumps, floating the intake of a pump, or any other method for minimizing and retaining the suspended solids. If the Qualified Inspector determines that a pumping operation is causing turbidity problems, the Contractor shall halt said operation until a means of controlling the turbidity is submitted by the Contractor in writing to the Engineer, approved in writing by the Engineer and implemented by the Contractor. No discharge of dewatering wastewater shall contain or cause a visible oil sheen, floating solids or foaming in the receiving water. If required, all activities are to be performed in compliance with the Department’s Standard Specifications. 13 Post-Construction Stormwater Management (All controls in this section must be in conformance with the 2024 SWQ Manual and the Department's qualified product list. Be sure to use the same call outs for structures as in the manual) The Qualified Inspector may consider BMP’s to be installed during the construction process to minimize the discharge of pollutants, and stormwater discharges that will occur after construction operations have been completed. • Minimal Curbing: Curbing shall be avoided wherever possible to maximize overland sheet flow and encourage infiltration. See if this can be moved elsewhere • Outlet Protection: Riprap outlet protection shall be used at the proposed outlet to decrease velocity and the potential for erosion. (i.e. apron, splash pad…) • Catch Basins w/ 4 ft. Sumps and Hoods: Catch basins shall be used, especially adjacent to outlets, to intercept pollutants and debris. • Street Sweeping: Street sweeping shall be performed as required to clean debris/sediment prior to leaving the site. • Hydrodynamic Particle Separator: Hydrodynamic Particle Separators shall be installed and cleaned as required to reduce the levels of TSS and provide treatment to stormwater prior to continuing to downstream drainage systems. Post-Construction Guidelines After the project is complete, the Department will perform the following maintenance and restorative measures: • Litter/debris and sweepings will be removed from the site regularly. • Mowing and maintenance of the turf areas and vegetated areas will occur, as needed. • Riprap outlet protection will be inspected and repaired, as needed. • Stormwater drainage system will be cleaned of sediment/debris, as directed by the Qualified Inspector . • Identify, inspect, and maintain all stormwater quality BMP’s included within the project, as per the MS4 or manufacturer recommendations. Post Construction Performance Standards and Control Measure Redevelopment: For sites that are already developed where there is more than 40% effective impervious cover, the site must be designed to retain on-site half the water quality volume for the site and provide 14 additional stormwater treatment without retention for discharges up to the full water quality volume for sediment, floatables and nutrients to the maximum extent achievable using control measures that are technologically available and economically practicable and achievable in light of best industry practice. If this retention and treatment cannot be achieved, describe: • The measures taken to maximize runoff reduction on site. • The reasons those are the maximum extent achievable. • The alternative retention volume you are providing; and • A description of the measures used to provide additional treatment above the alternative volume. For Roadway and other linear redevelopment projects: • For the developed portion of the ROW: o If the full retention standard cannot be met; describe the alternative retention provided and the treatment measures provided. If the effective impervious cover will not be increased within a given watershed, stormwater treatment measures must be provided, but retention of half the water quality volume is NOT required. Permit says implement additional stormwater treatment. In order to comply with the Department’s MS4 Permit requirements. projects shall seek to reduce the effective impervious cover (as defined in 12/31/20 Construction SW Permit) to the maximum extent practicable. “Effective Impervious Cover” is the area of impervious cover that is hydraulically connected to a water or wetland by means of continuous paved surfaces, gutters, swales, ditches, drain pipes or other conventional conveyance and detention structures that do not reduce runoff volume. Impervious cover is a surface composed of any material that impedes or prevents infiltration of water into the soil. Impervious surfaces shall include, but are not limited to, roofs, solid decks, driveways, patios, sidewalks, parking areas, tennis courts, concrete or asphalt streets, or compacted soils or compacted gravel surfaces. Pre-Development: Effective impervious cover = Impervious cover hydraulically connected to water/wetlands All area hydraulically connected to water/wetlands Effective impervious cover = . 0 acres (pavement) 0 acres Effective impervious cover (pre-development) = 0% Post-Development: Effective impervious cover = Impervious cover hydraulically connected to water/wetlands All area hydraulically connected to water/wetlands 15 Effective impervious cover = . 2.1 acres . 3.4 acres Effective impervious cover (post-development) = 62% Required Water Quality Volume (WQV) Subsurface Infiltration Field #1 (PSIS-1) This subsurface infiltration field is located in the proposed landscape area and pavement, west of the proposed residential building. It collects and provides treatment for all the stormwater runoff from the roof, as well as the parking area. The system utilizes 84” perforated CMP pipes configured in five rows. The proposed bottoms of the field and pipe inverts are 142’. The dimensions of the field is 155-feet x 49-feet for a total bottom area of 7,595 Square Feet. The volume provided is 29,441 Cubic Feet in the chambers and 12,518 Cubic Feet in the stone voids for a total volume of 41,968 Cubic Feet. The system is designed to store and infiltrate up to the required treatment amount. The on-site stormwater management system has been designed to capture, detain, and treat stormwater runoff from the on-stormwater runoff while capturing and detaining stormwater runoff from the offsite tributary area, which will improve runoff conditions. A hydrodynamic particle separator (CDS Unit) has been provided to minimize the number of contaminants that may flow into the system. The subsurface infiltration system has three inlets from CDS Units, which directs flow into the system.. 𝑉𝑃𝑉=(𝑃)∗(𝑃)∗(𝐴)(1𝑐𝑟/12�ℎ𝑙) 𝑉�𝑐𝑟𝑐: 𝑉𝑃𝑉 = 𝑉𝑎𝑟𝑐𝑟 𝑃𝑟𝑎𝑙�ℎ𝑟𝑦 𝑉𝑙𝑙𝑟𝑙𝑐 𝑃 = 𝑉𝑙𝑙𝑟𝑙𝑐𝑟𝑟�ℎ𝑐 𝑃𝑟𝑙𝑙𝑐𝑐 𝐶𝑙𝑐𝑐𝑐�ℎ𝑐�ℎ𝑐𝑙𝑟 (𝑐�ℎ𝑙𝑐𝑙𝑟�ℎ𝑙𝑙𝑙𝑐𝑟𝑟) = 0.05 +0.009(𝐼) 𝐼 = 𝑃𝑐𝑟𝑐𝑐𝑙𝑟 𝐼𝑙𝑙𝑐𝑟𝑟�ℎ𝑙𝑟𝑟 𝐶𝑙𝑟𝑐𝑟 = 90,735 𝑃𝐹 / 148,322 𝑃𝐹 = 62 % 𝐴= 𝐶𝑟𝑎�ℎ𝑙𝑎𝑐𝑐 𝐴𝑟𝑐𝑎 �ℎ𝑙 𝐴𝑐𝑟𝑐𝑟 = 148,322 𝑃𝐹=3.4 𝐴𝐶 𝑃=0.05 +0.009(𝐼) 𝑃=0.05 +0.009(62) 𝑃=0.608 𝑉𝑃𝑉=1.30 ∗0.608 ∗148,322 (1𝑐𝑟/12�ℎ𝑙) 𝑉𝑃𝑉=9,770 𝐶𝐹=0.224 𝑎𝑐𝑟𝑐 𝑐𝑐𝑐𝑟 𝑃𝑟𝑙𝑙𝑙𝑟𝑐𝑐 𝑉𝑙𝑙𝑟𝑙𝑐 𝑙𝑟𝑙𝑟�ℎ𝑐𝑐𝑐 41,968 𝐶𝐹 16 Other Development: A stormwater management system has been designed consistent with the Connecticut Stormwater Quality Manual that will improve upon the current stormwater runoff conditions in terms of peak flow control, recharge, and water quality from pre-development conditions. Runoff control, water quality improvement, and groundwater recharge will be accomplished by implementing the following drainage improvements: • Collect storm runoff in catch basins with deep sumps and hooded outlets, • Route runoff through hydrodynamic particle separators for additional removal of Total Suspended Solids (TSS), • Construction of a subsurface infiltration systems designed to retain and recharge runoff, thereby reducing the hydraulic burden on the existing drainage system. Runoff Reduction and LID Practices The proposed stormwater management measures described above will not have any adverse impacts to the adjacent properties. Runoff generated from storms up to the 100-year storm will be mitigated through the various on-site closed drainage systems prior to discharging offsite. Water quality will be enhanced over existing conditions, resulting in an overall improvement in storm runoff from the Site compared to pre-development conditions. Suspended Solids and Floatable Removal The onsite stormwater management system has been designed to collect, treat and infiltrate the first inch of rain on-site via deep sump catch basins, hydrodynamic particle separators, and subsurface infiltration system, achieving greater than 80% Total Suspended Solids (TSS) pollutant removal rates. Therefore, the stormwater management system will minimize the discharge of suspended solids and floatable (e.g., oil and grease, other floatable liquids, floatable solids, trash, etc.) Velocity Dissipation: Velocity dissipation devices shall be placed at discharge locations and along the length of any outfall channel as necessary to provide a non-erosive velocity flow offsite so that the existing, downstream characteristics and functions are maintained and protected. 17 Other Controls (Non-Structural) Waste Disposal Construction site waste shall be properly managed and disposed of during the entire construction period. The following is applicable: • A waste collection area will be designated. The selected area will minimize truck travel through the site and will not drain directly to the adjacent wetlands. • Waste collection shall be scheduled regularly to prevent the containers from overfilling. • Spills shall be cleaned up immediately. • Defective containers that may cause leaks or spills will be identified through regular inspection. Any found to be defective will be repaired or replaced immediately. • Any stockpiling of materials should be confined to the designated area as approved by the Qualified Inspector . Washout Areas Washout of applicators, containers, vehicles, and equipment for concrete shall be conducted in a designated washout area. No surface discharge of washout wastewaters from the area will be allowed. All concrete wash water will be directed into a container or pit such that no overflows can occur. Washout shall be conducted in an entirely self-contained system and will be clearly designed and flagged or signed where necessary. The washout area shall be located outside of any buffers and at least 50 feet from any stream, wetland or other sensitive water or natural resources as determined or designated by the Department’s Office of Environmental Planning or the project Qualified Inspector . Washout Area(s) will be site located by the Contractor, approved by the Qualified Inspector and the SWPCP revised, as appropriate. The “Concrete Washout Area” detail Concrete Washout Detail shows the recommended method of construction for the washout area. The designated area shall be designed and maintained such that no overflows can occur during rainfall or after snowmelt. Anti-tracking Pads and Dust Control (Form 818- Sections 2.11, 9.39, 9.42, and 9.43) Off –site vehicle tracking of sediments and the generation of dust shall be minimized. Temporary anti-tracking pads from the active work site to the existing pavement will be installed and maintained at the locations shown on the plans. The Contractor shall: • Maintain the entrance in a condition which will prevent tracking and washing of sediment onto paved surfaces. 18 • Provide periodic top dressing with additional stone or additional length as conditions demand. • Repair any measures used to trap sediment as needed. • Immediately remove all sediment spilled, dropped, washed or tracked onto paved surfaces. • Ensure roads adjacent to a construction site are left clean at the end of each day. If the construction entrance is being properly maintained and the action of a vehicle traveling over the stone pad is not sufficient to remove the majority of the sediment, then the contractor shall either: • Increase the length of the construction entrance, • Modify the construction access road surface, or • Install washing racks and associated settling area or similar devices before the vehicle enters a paved surface. For construction activities which cause airborne particulates, wet dust suppression shall be utilized. Construction site dust will be controlled by sprinkling the ground surface with water until it is moist on an as-needed basis. The volume of water sprayed shall be such that it suppresses dust yet also prevents the runoff of water. Maintaining and Storing Vehicles and Equipment- Storage of Chemicals & Petroleum Products The Contractor shall take measures to prevent any contamination to wetlands and watercourses while maintaining and storing construction equipment on the site. All chemical and petroleum containers stored on site shall be provided with impermeable containment which will hold at least 110% of the volume of the largest container, or 10% of the total volume of all containers in the area, whichever is larger, without overflow from the containment area. All chemicals and their containers shall be stored under a roofed area except for those stored in containers of 100-gallon capacity or more, in which case double-walled tanks will suffice. Accumulation of rainwater within secondary containment must be visually inspected for sheen prior to being discharged. If any sheen is identified; the accumulated water must be removed by the Contractor to an appropriate off-site location. Cold Water Stream Habitat For construction activities within a Cold-Water Stream Habitat watershed, the one hundred (100) foot undisturbed buffer specified is that section must be verified post-construction and, where such buffer is located within the boundaries of the construction site, supplemented with additional plantings as necessary to maintain canopy/stream cover. • The construction activities associated with the project are not within a Cold-Water Stream Habitat watershed per the online CT Dept. of Energy and Environmental Protection Cold Water Habitat mapping tool. o Cold Water Stream Habitat Map Application 19 Inspections The Qualified Inspector will conduct site inspections once a week or after any rain event of 0.1” or greater. The Qualified Inspector conducting inspections shall fill out a Construction Site Environmental Inspection Report (CSEIR) for each inspection described below. Each report shall be retained as a part of the SWPCP. The report shall include a statement that, in the judgment of the Qualified Inspector(s) conducting the site inspection, the site is either in compliance or out of compliance with the terms and conditions of the Plan and permit. If the site inspection indicates that the site is out of compliance, the inspection report shall include a summary of the remedial actions required to bring the site back into compliance, review Keeping Plans Current. Plan Implementation Inspections For each phase of construction, the site shall be inspected at least once within the first 30 days of construction activity and at least three times, with 7 or more days between inspections, within the first 90 days of construction activity to confirm compliance and proper initial implementation of all control measures. Routine Inspections The Permittee will maintain a rain gauge on-site to document rainfall amounts. During construction, all areas disturbed by the construction activity that have not been stabilized, all erosion and sediment control measures, structural control measures, soil stockpile areas, washout areas, and locations where vehicles enter or exit the site shall be inspected for evidence of or the potential for pollutant entering the drainage systems and impacts to the receiving waters at least every seven (7) calendar days and within 24 hours of the end of a storm that generates a discharge. For storms that end on a weekend, holiday, or other time in which normal working hours will not commence within 24 hours, an inspection is required within 24 hours following any storm in which 0.1 inches or greater of rain occurs. For lesser storms, inspection shall occur immediately upon the start of subsequent normal working hours. Where sites have been temporarily or finally stabilized, such inspection shall be conducted at least weekly until final stabilization has been achieved. Qualified Inspectors provided by the Department’s Eastern District Office shall conduct inspections. The following items shall be inspected as described below: Item Procedure Parking Lot & Roadways The parking lot and roadways in and around the project site should be inspected weekly to find if any trash or debris is present. 20 Landscaped areas Landscaped areas within the project site should be inspected weekly for any trash or debris. Compactor/Dumpster The compactor/dumpster area should be inspected weekly for any trash or debris in and around the area. Property Perimeter The property perimeter should be inspected weekly for any trash or debris. Catch Basins Catch basins should be inspected semi-annually for any trash, oil sheen, hood (securely fastened), and excessive sediment. Catch basins should be cleaned annually. Curbing Curbing should be inspected semi-annually for structural conditions. Hydrodynamic Particle Separators (CDS Units) Hydrodynamic Particle Separators (CDS Units) should be inspected semi-annually for trash, excessive sediment, structural condition. Post-Construction Inspection Upon completion of construction activities and stabilization of the site, all post-construction stormwater structures, including catch basins, hydrodynamic particle separators, StormTech Isolator Rows, shall be cleaned of construction sediment or debris and the site inspected to confirm compliance with all post-construction stormwater management requirements. Sediment shall be properly disposed of in accordance with all applicable laws, regulations and guidelines. Any remaining sediment control system(s) SCS shall be removed prior to acceptance of the project by the Department. Final Stabilization Inspection Once the site has achieved final stabilization, the site shall be inspected to confirm stabilization is maintained, and a Notice of Termination Form shall be submitted. 21 Keeping Plans Current Revisions to Stormwater Pollution Control Plans The Department shall amend the Plan if the actions required by the Plan fail to prevent pollution or otherwise comply with provisions of the General Permit. The Plan shall also be amended whenever there is a change in contractors or sub-contractors at the site, or a change in design, construction, operation, or maintenance at the site which has not otherwise been addressed in the plan. Resubmission is for extenuating circumstance in which new calculations are required such as the addition a new outfall or a modification to a stormwater quality structure within the project limits and not for modifications such as staging/access road relocations. Additionally, resubmission is applicable if there is a change in run off or discharge of pollutants. If the results of the inspections require modifications to the Stormwater Pollution Control Plan, the plans shall be revised as soon as practicable after the inspection. Such modifications shall provide for a timely implementation of any changes to non-engineered controls on the site within 24 hours and implementation of any changes to the plan within 3 (three) calendar days following the inspection. For Engineered measures, corrective actions shall be implemented on site within 7 (seven) days and incorporated into a revised Plan within 10 (ten) days of the date of inspection. In no event shall the requirements to keep the Plan current or update a Plan, relieve the permittee and their contactor(s) of the responsibility to properly implement any actions required to protect the waters of the State and to comply with all conditions of the permit. 22 Contractors General This section identifies all Contractors and Subcontractors who will perform on site actions which may reasonably be expected to cause or have the potential to cause pollution of the waters of the State. Certification Statement All contractors and subcontractors must sign the attached statement. All certifications will be included in the Stormwater Pollution Control Plan. State Project No. TBD Residential Development Montville, CT “I certify under penalty of law that I have read and understand the terms and conditions of the General Permit for the Discharge of Stormwater and Dewatering Wastewaters from Construction Activities. I understand that as Contractor on the project, I am covered by this General Permit, and must comply with the terms and conditions of this permit, including, but not limited to, the requirements of the Stormwater Pollution Control Plan prepared for this project.” GENERAL CONTRACTOR Signed:________________________ Date:_______________________ Title: TBD Firm: TBD Telephone: __________________ Address: _TBD______ ________TBD_______ SUBCONTRACTOR Signed: ___TBD_________________ Date:__________________________ Title:_____TBD__________________ Firm:_____TBD__________________ Telephone:_____________________ Address:___TBD_________________ _______________________________ 23 General: This Stormwater Pollution Control Plan (SWPCP) is prepared to comply with the requirements for the General Permit for the Discharge of Stormwater and Dewatering Wastewaters from Construction Activities. Also, to be considered part of the SWPCP are the proposed construction plans, special provisions, and the Connecticut Department of Transportation’s “Standard Specifications for Roads, Bridges and Incidental Construction” (Form 818) including supplements thereto and the 2024 Connecticut Guidelines for Erosion and Sediment Control (2002 E&S Guidelines) and 2024 Stormwater Quality Manual (2024 SWQ Manual). 24 List of applicable Figures / Plans: Appendix A – Figures • USGS Map • Soils Map • FEMA Flood Insurance Map • Existing Watershed Plan • Proposed Watershed Plan • Natural Diversity Data Base Areas Map – Montville, CT Appendix B – Plan Sheets • Demolition and Erosion Control Plan • Demolition and Erosion Control Notes • Grading and Drainage Plan • Erosion Control Details • Applicable Stormwater details • Overall Landscape Plan Appendix C- Connecticut DEEP General Permit for the Discharge of Stormwater and Dewatering Wastewaters from Construction Activities Appendix D- CTDOT MS4 Project Design Maximum Extent Practicable Worksheet o CTDOT MS4 Maximum Extent Possible (MEP) sheet Appendix E- Construction Site Environmental Inspection Report (CSEIR) o CSEIR Form Appendix F – Notice of Termination Form o General Permit for the Discharge of Stormwater & Dewatering Wastewaters from Construction Activities – Notice of Termination Form APPENDIX A - FIGURES • USGS Map • Soils Map • FEMA Flood Insurance Map • Existing Watershed Plan • Proposed Watershed Plan • Natural Diversity Data Base Areas Map – Montville, CT SITE Copyright © 2024 by R.J. O'Connell & Associates, Inc. RJO'CONNELL & ASSOCIATES, INC. CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS FIGURE 1 USGS MAP SCALE:DATE:08/27/2024 1"=1000' 0 GRAPHIC SCALE IN FEET 1,000 500 1,000 2,000 N 2268-2284 CONN. ROUTE 32 MONTVILLE, CT 06382 HYDROLOGIC SOIL GROUP MAP UNIT SYMBOL MAP UNIT NAME RATING 29B AGAWAM FINE SANDY LOAM, 3 TO 8 PERCENT SLOPES B 34B MERRIMAC FINE SANDY LOAM, 3 TO 8 PERCENT SLOPES A 62D CANTON AND CHARLTON FINE SANDY LOAMS, 15 TO 35 PERCENT SLOPES, EXTREMELY STONY B 73E CHARLTON-CHATFIELD COMPLEX, 15 TO 45 PERCENT SLOPES, VERY ROCKY B 306 UDORTHENTS-URBAN LAND COMPLEX B (UDORTHENTS) D (URBAN) Copyright © 2024 by R.J. O'Connell & Associates, Inc. RJO'CONNELL & ASSOCIATES, INC. CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS FIGURE 2 NRCS WEB SOIL SURVEY MAP SCALE:DATE:08/27/2024 AS SHOWN N 2268-2284 CONN. ROUTE 32 MONTVILLE, CT 2268-2284 CONN. ROUTEMONTVILLE, CT 06382Drawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Reports\Stormwater Pollution Control Plan\Figures\24029_FIG-2 FEMA Firm Map.dwg Aug 27, 2024 - 15:09pm Copyright © 2024 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERSFIGURE 3FEMA FLOOD INSURANCE RATE MAPSCALE:DATE:08/27/20241"=500'0GRAPHIC SCALE IN FEET5002505001,000NSITEREFERENCE: FEMA FLOOD INSURANCE RATE MAP, NEW LONDONCOUNTY, CONNECTICUT PANEL 351 OF 554, MAP NUMBER 09011C0351GEFFECTIVE DATE JULY 18, 2011 MMMwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwDAA-OSQ2 = 0.72 CFSQ10 = 3.65 CFSQ25 = 7.75 CFSQ100 = 9.77 CFSEX1-1TOTAL AREA = 156,264 SFTOTAL IMP. = 0 SFCN = 61Tc = 12.4 MINUTESEX-OS1TOTAL AREA = ±9 ACRESCN = 53Tc = 35.3 MINUTESDAA-1Q2 = 1.38 CFSQ10 = 4.21 CFSQ25 = 7.44 CFSQ100 = 8.97 CFSCopyright © 2022 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERSFIGURE 4EXISTING WATERSHED PLANSCALE:1"=50'0GRAPHIC SCALE IN FEET603060120N40 TUNXIS AVENUEBLOOMFIELD, CT 06002DATE:08/27/2024WATERSHED BOUNDARYLEGENDBUILDINGOPEN SPACE-GRASS/WOODSOPEN SPACE-WOODS/BRUSHDISCHARGE ANALYSIS AREAPAVEMENT/IMPERVIOUSTc PATHwwDAA-1 2268-2284 CONN. ROUTE 32MONTVILLE, CTCopyright © 2024 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERSNATURAL DIVERSITY DATABASESCALE:DATE:08/27/20241"=6000'N APPENDIX B - PLAN SHEETS • Demolition and Erosion Control Plan • Demolition and Erosion Control Notes • Grading and Drainage Plan • Erosion Control Details • Applicable Stormwater details • Overall Landscape Plan G50' WETLANDREVIEW AREAAPPROXIMATE LIMITSOF PROPOSEDBUILDING PADX X X X X XXXXXXXXXXXXXXXXXXTEMPORARY DRAINAGE SWALEWITH CHECK DAMS (TYP.)INSTALL WATTLEPROTECTION ANDFILTER BAG (TYP.)INSTALL WATTLEPROTECTION ANDFILTER BAG (TYP.)COMPOSTFILTER SOCKWITH SILTFENCE (TYP.)30'x50' TEMPORARYVEHICLE TRACKING PADCONSTRUCTION ENTRANCECONSTRUCTIONFENCE GATECOMPOSTFILTER SOCKWITH SILTFENCE (TYP.)COMPOST FILTERSOCK WITH SILTFENCE (TYP.)INSTALL TEMPORARYCONSTRUCTIONFENCE IF NEEDED (TYP.)INSTALLTEMPORARYCONSTRUCTIONFENCE IFNEEDED (TYP.)CLEAR ANDGRUB EXISTINGSITE (TYP)CLEAR ANDGRUB EXISTINGSITE (TYP)CLEAR ANDGRUB EXISTINGSITE (TYP)CLEAR ANDGRUB EXISTINGSITE (TYP)TEMPORARY DRAINAGE SWALEWITH CHECK DAMS (TYP.)TEMPORARY DRAINAGESWALE WITH CHECKDAMS (TYP.)CATCH BASIN/SEDIMENTTRAP AND BEEHIVE FRAMEAND GRATE W/4 FT. SUMP18" D18" DOS-DMH2OS-FESI=142.00TEMPORARY LEVEL SPREADER WITHCURB EDGE. CONTRACTOR TOINSPECT AND MAINTAINTHROUGHOUT CONSTRUCTION (TYP.)OS-DMH1TEMPORARY RISERWITH STONE BERM(SEE DWG. C-5 FORDETAILS)FES-1I=148.00DMH-OS2 W/ DEEP SUMPR=152.00I=148.30(DMH-OS1)I=1148.20(FES-18" D18" D 18" DEXISTING UTILITY POLE TO REMAINCONTRACTOR TO COORDINATEMODIFYING GUY WIRES WITH THEUTILITY COMPANY (TYP)TEMPORARY SEDIMENTATION BASIN.BOTTOM OF TEMPORARY SEDIMENT BASINS TO BEONE (1') FOOT ABOVE THE PROPOSED BASIN BOTTOMUNTIL AREAS ARE PERMANENTLY STABILIZED. UPONSTABILIZATION OF THE TRIBUTARY AREAS, THEBOTTOM OF BASINS CAN BE EXCAVATED TO THEPROPOSED ELEVATIONS AND STABILIZED.SEE DWG. C-2 FOR DETAILSTEMPORARY SEDIMENTATION BASIN.BOTTOM OF TEMPORARY SEDIMENT BASINS TO BEONE (1') FOOT ABOVE THE PROPOSED BASIN BOTTOMUNTIL AREAS ARE PERMANENTLY STABILIZED. UPONSTABILIZATION OF THE TRIBUTARY AREAS, THEBOTTOM OF BASINS CAN BE EXCAVATED TO THEPROPOSED ELEVATIONS AND STABILIZED.SEE DWG. C-2 FOR DETAILSDMH-OS1 W/ DEEP SUMPR=153.10I=149.40(HW-1)I=149.30(DMH-OS2)TEMPORARY RISERWITH STONE BERM(SEE DWG. C-5 FORDETAILS)TEMPORARY DISTURBEDAREA = ±432 SFAPPROXIMATELY 9,770 SFOF 50' UPLAND REVIEWAREA BEING DISTURBEDPERMANENTDISTURBEDAREA = ±636 SFEXISTING VEGETATION TO REMAINAND BE PROTECTED THROUGHOUTCONSTRUCTION (TYP.)EXISTING VEGETATION TO REMAINAND BE PROTECTED THROUGHOUTCONSTRUCTION (TYP.)18" DEXISTINGGUIDE RAILTO REMAINREMOVEEXISTINGGUIDE RAILEXISTING ADARAMP TO REMAINDrawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Main\24029_C-1 Demolition and Erosion Control Plan.dwg Sep 25, 2024 - 16:08pm 24029HORIZON VIEWMONTVILLE, CT20 AVON MEADOW LANEAVON, CT 06001DRAWING NUMBER:PROJECT NUMBER:Copyright © 2024 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS80 MONTVALE AVENUE , SU ITE 201 STONEHAM, MA 02180PHONE: 781 .279.0180 RJOCONNELL.COM NO.DATEREVISIONDRAWING NAME:PREPARED FOR:DESIGNED BY:DRAWN BY:REVIEWED BY:DATE:PROJECT NAME:SCALE:PREPARED BY:SEAL:NO.DATEREVISION 1.09/25/2024SUBMITTED TO INLAND WETLANDS COMMISSIONC-1DEMOLITION ANDEROSION CONTROLPLANRWSWJHBPD/RWS09/25/20241" = 30'0GRAPHIC SCALE IN FEET30153060RJOCNWATTLE INLET (SINGLE CB)WATTLE INLET (DOUBLE CB)EXISTING VEGETATION TO REMAINSTRAW WATTLECONSTRUCTION FENCESILT FENCELIMIT OF WORKPROPOSED BUILDING PADEXISTING LANDSCAPE AREA TOBE REMOVEDLEGENDNOTES:1.SEE DRAWING N-1 FOR GENERAL NOTES,EROSION CONTROL NOTES, DEMOLITIONNOTES, GRADING & DRAINAGE NOTES,UTILITY NOTES, AND PARKING ANDTRAFFIC CONTROL SIGN SCHEDULE.2.SEE DRAWING C-5 THROUGH C-10 FORDETAILS. N-1GENERALNOTESRWSWJHBPD/RWS09/25/2024NOT TO SCALEI.GENERAL NOTES:1.THE CONTRACTOR IS SPECIFICALLY ADVISED THAT THE LOCATION AND/OR ELEVATION OF EXISTING UTILITIES ANDSTRUCTURES AS SHOWN ON THESE PLANS IS BASED ON RECORDS OF VARIOUS UTILITY COMPANIES AND WHEREPOSSIBLE, MEASUREMENTS TAKEN IN THE FIELD. THIS INFORMATION IS NOT TO BE RELIED ON AS BEING EXACT ORCOMPLETE. THE LOCATION OF ALL UNDERGROUND UTILITIES AND STRUCTURES ESPECIALLY WHERE NEW UTILITIESCONNECT TO OR CROSS EXISTING, SHALL BE VERIFIED IN THE FIELD BY THE CONTRACTOR PRIOR TO THE START OFCONSTRUCTION. THE CONTRACTOR MUST CONTACT THE APPROPRIATE UTILITY COMPANY, ANY GOVERNING PERMITTINGAUTHORITY, AND "CALL BEFORE YOU DIG" (1-800-922-4455 OR 811) AT LEAST 72 HOURS PRIOR TO ANY EXCAVATION WORKTO REQUEST EXACT FIELD LOCATION OF UTILITIES AND THE ENGINEER SHALL BE NOTIFIED IN WRITING OF ANY UTILITIESINTERFERING WITH THE PROPOSED CONSTRUCTION AND APPROPRIATE REMEDIAL ACTION TAKEN BEFORE PROCEEDINGWITH THE WORK. IT SHALL BE THE RESPONSIBILITY OF THE CONTRACTOR TO RELOCATE ALL EXISTING UTILITIES WHICHCONFLICT WITH THE PROPOSED IMPROVEMENTS SHOWN ON THE PLANS.2.THE EXISTING INFORMATION INCLUDING BUT NOT LIMITED TO: BOUNDARY LINE, UTILITY INFORMATION ANDTOPOGRAPHY HAS BEEN TAKEN FROM PLANS ENTITLED "PROPERTY/TOPOGRAPHIC SURVEY", PREPARED BY F.A.HESKETH & ASSOCIATES, DATED SEPTEMBER 5, 2024.3.THE CONTRACTOR SHALL BE RESPONSIBLE FOR ESTABLISHING AND MAINTAINING ALL HORIZONTAL CONTROL POINTSAND VERTICAL BENCH MARKS NECESSARY FOR THE WORK.4.THE CONTRACTOR IS RESPONSIBLE FOR OBTAINING AND PAYING FOR ANY PERMITS AND/ORCONNECTION/DISCONNECTION FEES REQUIRED TO CARRY OUT THE WORK INCLUDING BUT NOT LIMITED TO DEMOLITION.5.DISPOSAL OF ALL DEMOLISHED MATERIALS IS THE RESPONSIBILITY OF THE CONTRACTOR AND MUST BE DISPOSED OFOFF-SITE IN ACCORDANCE WITH ALL FEDERAL, STATE AND MUNICIPAL REQUIREMENTS. NO ON-SITE BURIAL PITS AREALLOWED.6.THE CONTRACTOR SHALL BE RESPONSIBLE FOR VERIFICATION OF ALL INFORMATION SHOWN ON THESE PLANS PRIORTO THE START OF CONSTRUCTION. THE CONTRACTOR SHALL NOTIFY THE ENGINEER IN WRITING IMMEDIATELY OF ANYDISCREPANCIES BETWEEN ACTUAL FIELD CONDITIONS AND THE EXISTING FIELD CONDITIONS AS SHOWN ON THESEPLANS.7.THE CONTRACTOR SHALL REFER TO THE ARCHITECTURAL/BUILDING PLANS FOR ITEMS SUCH AS: BUILDING LOCATIONSAND DIMENSIONS, EXIT PORCHES, TRUCK DOCKS, UTILITY PENETRATIONS AND SIDEWALK LAYOUT. THE CONTRACTORSHALL NOTIFY THE OWNER/ENGINEER IN WRITING OF ANY DISCREPANCIES ENCOUNTERED.8.ALL CONSTRUCTION DUMPSTERS SHALL BE PROPERLY MAINTAINED. ALL DUMPSTERS SHALL BE LOCATED ON ABITUMINOUS CONCRETE OR CONCRETE SURFACE. THE CONTRACTOR SHALL BE RESPONSIBLE FOR TRASH DISPOSAL ONA REGULAR BASIS AND SHALL ENSURE THAT THE DUMPSTER AREAS ARE PROPERLY MAINTAINED.9.THE CONTRACTOR WILL BE RESPONSIBLE FOR THE GENERAL UPKEEP AND ROUTINE MAINTENANCE OF THE ENTIRE SITETO ENSURE AN AESTHETICALLY PLEASING APPEARANCE DURING ALL PHASES OF CONSTRUCTION.10.UNLESS OTHERWISE INDICATED, AREAS DISTURBED BY CONSTRUCTION SHALL BE RESTORED TO ITS ORIGINALCONDITION.11.EXISTING LANDSCAPE AREAS SHALL BE KEPT FREE OF DEBRIS AND SHALL BE MAINTAINED FREE OF PHYSICAL DAMAGE.DAMAGED PLANTS SHALL BE REPLACED IN KIND.12.THE CONTRACTOR SHALL FURNISH, INSTALL AND MAINTAIN ALL MATERIAL AND LABOR ASSOCIATED WITH TEMPORARYTRAFFIC CONTROL DEVICES FOR ALL PHASES OF CONSTRUCTION IN ACCORDANCE WITH M.U.T.C.D. STANDARDS AND ASAPPROVED BY THE OWNER'S REPRESENTATIVE.13.NO AUTHORIZED CONSTRUCTION ACTIVITY SHALL OCCUR ON OR AFFECT ABUTTING PROPERTIES. IF THE CONTRACTORMUST WORK ON AN ABUTTING PROPERTY, WRITTEN AUTHORIZATION SHALL BE OBTAINED FROM THE OWNER OF SAIDPROPERTY AND SHALL BE PROVIDED TO THE OWNER AND/OR OWNER'S REPRESENTATIVE PRIOR TO THE START OFWORK.14.IN THE EVENT OF A HAZARDOUS LEAK AND/OR SPILL THE OWNER, OWNER'S REPRESENTATIVE AND/OR GENERALCONTRACTOR WILL CONTACT THE DEPARTMENT OF PUBLIC HEALTH, THE FIRE DEPARTMENT, AND DEEP EMERGENCYRESPONSE AND SPILL PREVENTION AT 860-424-3388 OR 1-866--337-7745.15.ALL TYPES OF FILL MATERIAL IMPORTED TO THE SITE MUST BE CLEAN AND SUITABLE FOR THE USE AS SPECIFIED IN THESITE WORK SPECIFICATIONS. THE CONTRACTOR WILL PROVIDE THE OWNER'S GEOTECHNICAL ENGINEER AND/ORREPRESENTATIVE WITH RECORDS INDICATING THE TYPE, QUANTITY, ORIGIN AND SOURCE OF ANY FILL MATERIALIMPORTED TO THE SITE.16.AT THE COMPLETION OF THE JOB, THE CONTRACTOR SHALL PROVIDE THE OWNER AND/OR OWNER'S REPRESENTATIVE ACOMPLETE SET OF AS-BUILT PLANS. THE AS-BUILT PLANS ARE TO BE PREPARED BY AND STAMPED BY A LICENSEDPROFESSIONAL SURVEYOR. THE AS-BUILT PLAN WILL INCLUDE BUILDING LOCATION AND DIMENSIONS, FINISH FLOORELEVATIONS, LOCATION OF UTILITIES (RIM, INVERT, PIPE SIZE AND TYPE TO BE PROVIDED FOR SANITARY AND STORMDRAIN STRUCTURES), CURBING, ABOVE GRADE FEATURES, STRIPING, SIGNAGE, LANDSCAPING, ETC. AS INSTALLED.17.THE TEST PITS AND/OR SOIL BORING LOCATIONS AS SHOWN ON DWG. C-2 WERE PERFORMED BY WHITESTONEASSOCIATES, INC.. SOIL BORINGS AND TEST PIT EXCAVATIONS WERE TAKEN FOR THE PURPOSE OF DESIGN.18.SITE WORK CONSTRUCTION SHALL MEET OR EXCEED MONTVILLE'S ENGINEERING AND/OR DPW SPECIFICATIONS.19.THE CONTRACTOR SHALL NOTIFY THE TOWN AT LEAST FORTY EIGHT (48) HOURS PRIOR TO THE COMMENCEMENT OFSITE WORK CONSTRUCTION ACTIVITIES.20.PRIOR TO THE START OF CONSTRUCTION, THE BOUNDARY OF THE WETLAND RESOURCE AREAS WITHIN THE VICINITY OFTHE PROPOSED WORK AREA SHALL BE DELINEATED WITH EITHER WOODEN STAKES AND/OR FLAGGING BY APROFESSIONAL WETLAND SCIENTIST. ONCE IN PLACE, THE WETLAND BOUNDARY MARKERS SHALL BE MAINTAINED UNTILA CERTIFICATE OF COMPLIANCE HAS BEEN ISSUED BY THE CONSERVATION COMMISSION.II.EROSION CONTROL NOTES:1.ALL EROSION AND SEDIMENTATION CONTROL MEASURES SHALL BE INSTALLED AND/OR CONSTRUCTED IN ACCORDANCEWITH THE 2024 CONNECTICUT GUIDELINES FOR SOIL EROSION AND SEDIMENT CONTROL, THE CONNECTICUT DEEPGENERAL PERMIT FOR THE DISCHARGE OF STORM WATER AND DE-WATERING WATER FROM CONSTRUCTION ACTIVITIES,AND ALL LOCAL MUNICIPAL REGULATIONS.2.EROSION AND SEDIMENTATION CONTROL BEST MANAGEMENT PRACTICES (BMP'S) SHALL BE IN PLACE AND FUNCTIONINGPRIOR TO THE COMMENCEMENT OF ANY DEMOLITION, CLEARING AND GRUBBING ACTIVITIES OR EARTHWORKOPERATIONS. LOCATION OF THE EROSION CONTROL BARRIER MUST BE STAKED BY THE SITE SURVEYOR AND/OR SITEENGINEER, AND MUST BE INSPECTED AND VERIFIED TO THE APPROPRIATE TOWN OFFICIALS, IN WRITING, BY THE SITESURVEYOR AND/OR SITE ENGINEER PRIOR TO CONSTRUCTION. THE EROSION CONTROL BMP'S SHALL BE MAINTAINEDDURING CONSTRUCTION, AND SHALL REMAIN IN PLACE UNTIL ALL SITE WORK IS COMPLETE AND FINISHED GROUNDCOVER IS ESTABLISHED. ALL EROSION CONTROL BMP'S SHALL BE INSTALLED ON-SITE AND NOT ENCROACH ONTOABUTTING PROPERTIES.3.PRIOR TO COMMENCEMENT OF CONSTRUCTION ACTIVITIES AT THE SITE, THE CONTRACTOR SHALL ENGAGE ANINDIVIDUAL WITH SPECIFIC PROFESSIONAL TRAINING AND EXPERTISE IN EROSION AND SEDIMENT CONTROL. THEEROSION CONTROL MONITOR SHALL PREPARE A WEEKLY REPORT WHICH SHALL BE KEPT ON-SITE AT ALL TIMES ANDSHALL BE SHOWN TO LOCAL, AND STATE AGENTS UPON REQUEST. THIS REPORT SHALL INDICATE THE STATUS OF THEEROSION CONTROLS AND ANY MAINTENANCE REQUIRED AND PERFORMED. THIS REPORT SHALL CONFORM TO THEREQUIREMENTS OF THE CONNECTICUT DEEP GENERAL PERMIT FOR THE DISCHARGE OF STORM WATER ANDDE-WATERING WATERS FROM CONSTRUCTION ACTIVITIES AND STORM WATER POLLUTION CONTROL PLAN (SWPCP).4.THE PROJECT REQUIRES AN PERMIT FOR STORMWATER DISCHARGES ASSOCIATED WITH CONSTRUCTION ACTIVITIES.THE CONTRACTOR SHALL PERFORM ALL WORK INCLUDING BUT NOT LIMITED TO INSTALLATION, INSPECTIONS, CLEANING,REPAIRING, ETC. OF EROSION CONTROL MEASURES INSTALLED IN ACCORDANCE WITH THE STORMWATER POLLUTIONCONTROL PLAN (SWPCP).5.ALL EROSION AND SEDIMENT CONTROL MEASURES SHALL BE INSPECTED DAILY AND CLEANED, REPAIRED OR REPLACEDAS NECESSARY THROUGH-OUT CONSTRUCTION. EROSION AND SEDIMENT CONTROL MEASURES SHALL BE INSPECTEDAFTER EACH STORM EVENT AS OUTLINED IN THE STORM WATER POLLUTION PREVENTION PLAN (SWPPP).. REFER TO THESTORM WATER POLLUTION PREVENTION PLAN (SWPPP) FOR DETAILS REGARDING THE TYPE, INSTALLATION, INSPECTIONAND MAINTENANCE OF EROSION AND SEDIMENT CONTROL MEASURES DURING CONSTRUCTION.6.THE CONTRACTOR SHALL BE AWARE THAT SOIL AT THIS SITE IS PARTICULARLY SUSCEPTIBLE TO SOIL EROSION ANDSENSITIVE TO ITS CONSEQUENCES. IT SHOULD BE NOTED THAT THE EROSION CONTROL MEASURES AS SHOWN ON THEDRAWINGS DEPICT THE MINIMUM REQUIRED AND ARE REPRESENTATIVE OF A SINGLE PHASE OF CONSTRUCTION. THECONTRACTOR SHALL BE RESPONSIBLE FOR THE SITING, RELOCATION AND AUGMENTATION OF EROSION CONTROL BMP'SAS THE PROJECT PROGRESSES AND SITE CONDITIONS CHANGE.7.THE LIMIT OF WORK LINE FOR THE SITE TO BE CLEARED AND GRUBBED SHALL BE WITH SAME AS THE LIMIT OF WORKLINE NECESSARY FOR GRADING PURPOSES (I.E. THE GRADING LIMITS AROUND THE PERIMETER OF THE PROJECT AREA).8.THE CONTRACTOR SHALL KEEP ON-SITE, AT ALL TIMES, ADDITIONAL WATTLES, FILTER BAGS, SILT FENCE, ETC. FORINSTALLATION TO MITIGATE ANY EMERGENCY CONDITION.9.THE PROPOSED ON-SITE DRAINAGE SYSTEM SHALL BE INSTALLED AS SOON AS PRACTICABLE AND ALL INLETSPROTECTED WITH FILTER BAGS (SEE DETAIL). NO SEDIMENT SHALL BE ALLOWED TO ENTER THE ON-SITE OR OFF-SITEDRAINAGE SYSTEM AT ANY TIME.10.EARTHWORK ACTIVITIES ON SITE SHALL BE PERFORMED IN SUCH A MANNER THAT DIRECTS RAINFALL RUNOFF TO THEAPPROPRIATE EROSION CONTROL BEST MANAGEMENT PRACTICE (BMP'S) AS DEPICTED ON DRAWING C-1 TITLEDDEMOLITION AND EROSION CONTROL PLAN.11.STOCKPILES SHALL BE SURROUNDED ON THEIR PERIMETER WITH STAKED WATTLES AND/OR SILTATION FENCING TOPREVENT AND/OR TO CONTROL SILTATION AND EROSION. THE LOCATION OF THE STOCKPILE MAY BE MOVED ASAPPROVED BY THE EROSION CONTROL MONITOR. STOCKPILES SHALL BE COVERED SO THAT STORMWATER CANNOTINFILTRATE MATERIALS AND THEREBY RENDER THE MATERIAL UNSUITABLE FOR USE AS FILL.12.THE CONSTRUCTION ENTRANCE/EXIT AREA TO AND FROM THE SITE SHALL BE MAINTAINED IN A CONDITION THATPREVENTS TRACKING AND DISCHARGE OF SEDIMENT OFF-SITE. ALL SEDIMENT SPILLED, DROPPED, TRACKED OROTHERWISE DEPOSITED ON THE PUBLIC RIGHT-OF-WAY SHALL BE REMOVED IMMEDIATELY.13.ALL DISTURBED OR EXPOSED AREAS SUBJECT TO EROSION SHALL BE STABILIZED WITH MULCH OR SEEDED FORTEMPORARY VEGETATIVE COVER WHERE CONSTRUCTION ACTIVITIES HAVE PERMANENTLY CEASED OR HAVETEMPORARILY BEEN SUSPENDED FOR MORE THAN THIRTY (30) DAYS. WHEN FINAL GRADES ARE ACHIEVED IN ANYPORTION OF THE SITE, STABILIZATION MEASURES SHALL BE IMPLEMENTED WITHIN SEVEN (7) DAYS. ALL DISTURBEDAREAS ON-SITE MUST BE PERMANENTLY STABILIZED AS SHOWN ON THE SITE LANDSCAPE PLAN. PERMANENTSTABILIZATION MUST BE UNIFORM AND COMPLETE. AREAS WHICH REMAIN DISTURBED BUT INACTIVE FOR AT LEASTFOURTEEN (14) DAYS SHALL RECEIVE TEMPORARY SEEDING IN ACCORDANCE WITH THE MASSACHUSETTS EROSION ANDSEDIMENT CONTROL GUIDELINES. IN ALL CASES, STABILIZATION MEASURES SHALL BE IMPLEMENTED AS SOON ASPOSSIBLE IN ACCORDANCE WITH THE MASSACHUSETTS EROSION AND SEDIMENT CONTROL GUIDELINES. THE EROSIONCONTROL BARRIER MUST BE MAINTAINED UNTIL SITE VEGETATION IS STABILIZED AND INSPECTED BY THE OWNER'SREPRESENTATIVE FOR SITE COMPLIANCE.14.ANY DE-WATERING ACTIVITIES SHALL BE IN ACCORDANCE WITH SWPCP AND DISCHARGE TO A TEMPORARY BASIN,SETTLING TANK OR OTHER MEASURE TO ALLOW SETTLING OF SEDIMENT BEFORE RELEASE TO THE DRAINAGE SYSTEM.A DEWATERING PIT MUST BE CONSTRUCTED A MINIMUM DISTANCE OF FIFTY (50) FEET ON THE UPLAND SIDE FROM THEEROSION CONTROL BARRIER. LOCATION TO BE CONFIRMED BY THE SITE ENGINEER.15.ALL PROPOSED SLOPES STEEPER THAN 3:1 SHALL BE STABILIZED WITH A CURLEX EROSION CONTROL MATTINGMANUFACTURED BY AMERICAN EXCELSIOR COMPANY (OR ENGINEER APPROVED EQUAL) AND PROTECTED FROMEROSION. ADDITIONALLY, THESE AREAS ARE TO BE HYDROSEEDED.16.THE CONTRACTOR SHALL CONSTRUCT AT THE END OF EACH WORK DAY A TEMPORARY DIVERSION SWALE WHICHOUTLETS INTO A TEMPORARY SEDIMENT BASIN. THE TEMPORARY DIVERSION SWALE SHALL BE RELOCATED ASREQUIRED TO ACCOMMODATE EARTH WORK ACTIVITIES PERFORMED. CONTRACTOR TO INSPECT, MAINTAIN AND CLEANTEMPORARY DIVERSION SWALE AND BASIN AS OUTLINED IN THE STORM WATER POLLUTION PREVENTION PLAN (SWPPP)AND THE NPDES PERMIT REQUIREMENTS.17.THE LOCATION OF TEMPORARY DRAINAGE SWALES AND SEDIMENTATION TRAPS SHALL BE RELOCATED AS REQUIRED ASCONSTRUCTION PROGRESSES.18.FILTER BAGS AND/OR HAYBALE/WATTLE DIKES ARE TO BE INSTALLED AT ALL NEW AND EXISTING CATCH BASINS ASINDICATED ON DWG. C-1, AND REMAIN IN PLACE UNTIL ALL DISTURBED AREAS ARE PERMANENTLY STABILIZED. FILTERBAGS AND/OR HAYBALE DIKES ARE TO BE MAINTAINED AS OUTLINED IN THE STORM WATER POLLUTION CONTROL PLAN(SWPCP). NO SEDIMENT SHALL BE ALLOWED TO ENTER THE ON-SITE OR OFF-SITE DRAINAGE SYSTEMS AT ANY TIME.19.TO MINIMIZE THE MIGRATION OF DUST AND SILT FROM THE CONSTRUCTION SITE, THE FOLLOWING MEASURES SHALL BEIMPLEMENTED AS REQUIRED:·SPRAY DISTURBED AREAS WITH WATER DURING DRY AND WINDY DAYS·WASH WHEELS OF VEHICLES BEFORE LEAVING THE SITE·PERIODICALLY CLEAN SURROUNDING ROADWAYS NEAR THE ENTRANCE TO THE SITE·ALL VEHICLES HAULING MATERIAL TO AND FROM THE SITE SHALL PLACE SECURE COVERS OVER THEIR LOADS20.THE CONTRACTOR SHALL ANTICIPATE AND MODIFY EROSION CONTROL MEASURES BASED ON PAST, CURRENT ANDFORECASTED WEATHER CONDITIONS, SEASON AND ANTICIPATED FUTURE CONSTRUCTION ACTIVITIES.21.UPON COMPLETION OF ALL SITE WORK CONSTRUCTION, THE SITE CONTRACTOR SHALL INSPECT ALL EROSIONCONTROLS, ON-SITE CATCH BASINS AND PARTICLE SEPARATORS AND REMOVE ALL SEDIMENT AND TRASH DEBRIS THATHAS ACCUMULATED WITHIN SAID BMP'S AND STRUCTURES DURING THE COURSE OF CONSTRUCTION. ALL ON-SITECATCH BASINS AND PARTICLE SEPARATORS SHALL BE PUMPED 'DRY' AT THE CONCLUSION OF SITEWORK ACTIVITIES.22.PRIOR TO THE START OF ANY AUTHORIZED ACTIVITY THE GENERAL CONTRACTOR SHALL PREPARE A DUST CONTROLPLAN. THE DUST CONTROL PLAN WILL OUTLINE MEASURES TO CONTROL AND MITIGATE DUST DURING ALL PHASES OFDEMOLITION AND CONSTRUCTION AND IN ALL TYPES OF WEATHER CONDITIONS. THE DUST CONTROL PLAN SHALL BEIMPLEMENTED DURING ALL PHASES OF CONSTRUCTION AND WILL CONTINUE UNTIL PROJECT COMPLETION.23.THE CONTRACTOR SHALL REMOVE SEDIMENT FROM TEMPORARY SEDIMENT BASIN WHEN THEY ARE 25% FULL. ALLACCUMULATED SEDIMENT SHALL BE REMOVED FROM SEDIMENT BASINS AT THE COMPLETION OF THE PROJECT.ACCUMULATED SEDIMENT SHALL BE REMOVED AND DISPOSED OF IN ACCORDANCE WITH FEDERAL, STATE AND LOCALREQUIREMENTS.24.WINTER CONSTRUCTION AND STABILIZATION: THE WINTER CONSTRUCTION PERIOD IS FROM NOVEMBER 1 THROUGHAPRIL 15SEDIMENT BARRIERS: DURING FROZEN CONDITIONS, SEDIMENT BARRIERS MAY CONSIST OF EROSION CONTROL MIXBERMS OR ANY OTHER RECOGNIZED SEDIMENT BARRIERS AS FROZEN SOIL PREVENTS THE PROPER INSTALLATION OFHAY BALES OR SILT FENCES.MULCHING: ALL AREAS SHALL BE CONSIDERED UNSTABLE UNTIL SEEDED AND MULCHED. HAY AND STRAW MULCH SHALLBE APPLIED AT A RATE OF 150 LB. PER 1000 SF OR 3 TONS/ACRE (TWICE THE NORMAL ACCEPTED RATE) AND SHALL BEPROPERLY ANCHORED. EROSION CONTROL MIX MUST BE APPLIED WITH A MINIMUM 4 INCH THICKNESS. MULCH SHALLNOT BE SPREAD ON TOP OF SNOW. THE SNOW WILL BE REMOVED DOWN TO A 1-INCH DEPTH OR LESS PRIOR TOAPPLICATION. AFTER EACH DAY OF FINAL GRADING, THE AREA WILL BE PROPERLY STABILIZED WITH ANCHORED HAY ORSTRAW OR EROSION CONTROL MATTING. AN AREA SHALL BE CONSIDERED TO HAVE BEEN STABILIZED WHEN EXPOSEDSURFACES HAVE BEEN EITHER MULCHED OR ADEQUATELY ANCHORED SO THAT GROUND SURFACE IS NOT VISIBLETHROUGH THE MULCH. BETWEEN NOVEMBER 1 AND APRIL 15, ALL MULCH SHALL BE ANCHORED BY EITHER MULCHNETTING, ASPHALT EMULSION CHEMICAL, OR WOOD CELLULOSE FIBER. THE COVER WILL BE CONSIDERED SUFFICIENTWHEN THE GROUND SURFACE IS NOT VISIBLE THROUGH THE MULCH. AFTER NOVEMBER 1ST, MULCH AND ANCHORINGOF ALL EXPOSED SOIL SHALL OCCUR AT THE END OF EACH WORKDAY DURING FINAL GRADING ACTIVITIES.SOIL STOCKPILING: STOCKPILES OF SOIL OR SUBSOIL WILL BE MULCHED FOR OVER WINTER PROTECTION WITH HAY ORSTRAW AT TWICE THE NORMAL RATE OR WITH A 4-INCH LAYER OF EROSION CONTROL MIX. THIS WILL BE DONE WITHIN 24HOURS OF STOCKING AND REESTABLISHED PRIOR TO ANY RAINFALL OR SNOWFALL.SEEDING: BETWEEN THE DATES OF OCTOBER 15 AND APRIL 1, LOAM OR SEED WILL NOT BE REQUIRED. DURING PERIODSOF ABOVE FREEZING TEMPERATURES FINISHED AREAS SHALL BE FINE GRADED AND EITHER PROTECTED WITH MULCHOR TEMPORARILY SEEDED AND MULCHED UNTIL SUCH TIME AS THE FINAL TREATMENT CAN BE APPLIED. IF THE DATE ISAFTER NOVEMBER 1ST AND IF THE EXPOSED AREA HAS BEEN LOOMED, FINAL GRADED WITH A UNIFORM SURFACE, THENTHE AREA MAY BE DORMANT SEEDED AT A RATE OF 3 TIMES HIGHER THAN SPECIFIED FOR PERMANENT SEED AND THENMULCHED. DORMANT SEEDING MAY BE PLACED PRIOR TO THE PLACEMENT OF MULCH OR EROSION CONTROL BLANKETS.IF DORMANT SEEDING IS USED FOR THE SITE, ALL DISTURBED AREAS SHALL RECEIVE 4" OF LOAM AND SEED AT ANAPPLICATION RATE OF 5 LBS/1000 SF. ALL AREAS SEEDED DURING THE WINTER WILL BE INSPECTED IN THE SPRING BYREPLACING LOAM, SEED AND MULCH. IF DORMANT SEEDING IS NOT USED FOR THE SITE, ALL DISTURBED AREAS SHALLBE RE-VEGETATED IN THE SPRING.WINTER STABILIZATION OF DITCHES AND CHANNELS: ALL STONE-LINED DITCHES AND CHANNELS MUST BECONSTRUCTED AND STABILIZED BY NOVEMBER 15. ALL GRASS-LINED DITCHES AND CHANNELS MUST BE CONSTRUCTEDAND STABILIZED BY SEPTEMBER 1. IF A DITCH OR CHANNEL IS NOT GRASS-LINED BY SEPTEMBER 1, THEN ONE OF THEFOLLOWING ACTIONS MUST BE TAKEN TO STABILIZE THE DITCH:INSTALL A SOD LINING IN THE DITCH: A DITCH MUST BE LINED WITH PROPERLY INSTALLED SOD BY OCTOBER 1. PROPERINSTALLATION INCLUDES: PINNING THE SOD ONTO THE SOIL WITH WIRE PINS, ROLLING THE SOD TO GUARANTEECONTACT BETWEEN THE SOD ONTO AND UNDERLYING SOIL, WATERING THE SOD TO PROMOTE ROOT GROWTH INTO THEDISTURBED SOIL, AND ANCHORING SOD AT THE BASE OF THE DITCH WITH JUTE OR PLASTIC MESH TO PREVENT THE SODFROM SLOUGHING DURING FLOW CONDITIONS.STALL A STONE LINING IN THE DITCH: A DITCH MUST BE LINED WITH STONE RIP RAP BY NOVEMBER 15. CONTACTREGISTERED PROFESSIONAL ENGINEER TO DETERMINE THE STONE SIZE AND LINING THICKNESS NEEDED TOWITHSTAND THE ANTICIPATED FLOW VELOCITIES AND FLOW DEPTHS WITHIN THE DITCH.WINTER STABILIZATION OF DISTURBED SLOPES: ALL STONE-COVERED SLOPES GREATER THAN 15% MUST BECONSTRUCTED AND STABILIZED BY NOVEMBER 15. AND ALL SLOPES TO BE VEGETATED MUST BE SEEDED AND MULCHEDBY SEPTEMBER 1. IF A SLOPE TO BE VEGETATED IS NOT STABILIZED BY SEPTEMBER 1, THEN ONE OF THE FOLLOWINGACTIONS MUST BE TAKEN TO STABILIZE THE SLOPE.TEMPORARY VEGETATION AND EROSION CONTROL MATS: BY OCTOBER 1 THE DISTURBED SLOPE MUST BE SEEDED WITHWINTER RYE AT A SEEDING RATE OF 3 LBS PER 1000 SF AND THEN INSTALL EROSION CONTROL MATS OR ANCHOREDMULCH OVER THE SEEDING. IF THE RYE FAILS TO GROW AT LEAST 3 INCHES OR FAILS TO COVER AT LEAST 75% OF THESLOPE BY NOVEMBER 1, THEN THE CONTRACTOR WILL COVER THE SLOPE WITH A LAYER OF EROSION CONTROL MIX ORWITH STONE RIP RAP.SOD:THE DISTURBED SLOPE MUST BE STABILIZED WITH PROPERLY INSTALLED SOD BY OCTOBER 1. PROPERINSTALLATION INCLUDES THE CONTRACTOR PINNING THE SOD ONTO THE SLOPE WITH WIRE PINS, ROLLING THE SOD TOGUARANTEE CONTACT BETWEEN THE SOD AND UNDERLYING SOIL, AND WATERING THE SOD TO PROMOTE ROOTGROWTH INTO THE DISTURBED SOIL. THE CONTRACTOR WILL NOT USE LATE-SEASON SOD INSTALLATION TO STABILIZESLOPES HAVING A GRADE GREATER THAN 33% OR HAVING GROUNDWATER SEEPS ON THE SLOPE FACE.EROSION CONTROL MIX: EROSION CONTROL MIX MUST BE PROPERLY INSTALLED BY NOVEMBER 15. THE CONTRACTORWILL NOT USE EROSION CONTROL MIX TO STABILIZE SLOPES HAVING GRADES GREATER THAN 50% OR HAVINGGROUNDWATER SEEPS ON THE SLOPE FACE.STONE RIP RAP: PLACE A LAYER OF STONE RIP RAP ON THE SLOPE BY NOVEMBER 15. CONTACT THE PROFESSIONALENGINEER TO DETERMINE THE STONE SIZE NEEDED FOR STABILITY ON THE SLOPE AND TO DESIGN A FILTER LAYER FORUNDERNEATH THE RIP RAP.WINTER STABILIZATION OF DISTURBED SOILS: BY SEPTEMBER 15, ALL DISTURBED SOILS ON AREAS HAVING A SLOPELESS THAN 15% MUST BE SEEDED AND MULCHED. IF THE DISTURBED AREAS ARE NOT STABILIZED BY THIS DATE, THENONE OF THE FOLLOWING ACTIONS MUST BE TAKEN:TEMPORARY VEGETATION: BY OCTOBER 1, SEED THE DISTURBED SOIL WITH WINTER RYE AT A SEEDING RATE OF 3 LBSPER 1000 SF, LIGHTLY MULCH THE SEEDED SOIL WITH HAY OR STRAW AT 75 POUNDS PER 1000 SF, AND ANCHOR THEMULCH WITH PLASTIC NETTING. MONITOR GROWTH OF THE RYE OVER THE NEXT 30 DAYS. IF THE RYE FAILS TO GROW ATLEAST 3 INCHES OR FAILS TO COVER AT LEAST 75% OF THE DISTURBED SOIL BEFORE NOVEMBER 1, THEN MULCH THEAREA FOR WINTER PROTECTION AS DESCRIBED BELOW.SOD:STABILIZE THE DISTURBED SOIL WITH PROPERLY INSTALLED SOD BY OCTOBER 1. PROPER INSTALLATIONINCLUDES PINNING THE SOD ONTO THE SOIL WITH WIRE PINS, ROLLING THE SOD TO GUARANTEE CONTACT BETWEENTHE SOD AND UNDERLYING SOIL, AND WATERING THE SOD TO PROMOTE ROOT GROWTH INTO THE DISTURBED SOIL.MULCH:BY NOVEMBER 15, MULCH THE DISTURBED SOIL BY SPREADING HAY OR STRAW AT A RATE OF AT LEAST 150LBS PER 1000 SF ON THE AREA SO THAT NO SOIL IS VISIBLE THROUGH THE MULCH. IMMEDIATELY AFTER APPLYING THEMULCH, ANCHOR THE MULCH WITH PLASTIC NETTING TO PREVENT WIND FROM MOVING THE MULCH OFF THE DISTURBEDSOIL.III.DEMOLITION NOTES:1.PRIOR TO THE START OF ANY DEMOLITION ACTIVITIES, ON-SITE EROSION AND SEDIMENT CONTROL MEASURES ASSHOWN ON DRAWING C-1 MUST BE INSTALLED AND APPROVED BY THE OWNER'S REPRESENTATIVE.2.THE CONTRACTOR IS SPECIFICALLY CAUTIONED THAT ALL UTILITY SERVICES TO EXISTING STRUCTURE(S) MAY NOT BESHOWN. CONTRACTOR TO VERIFY UTILITY LOCATIONS VIA "CALL BEFORE YOU DIG" PRIOR TO THE COMMENCEMENT OFANY DEMOLITION ACTIVITY. EXISTING WATER AND SEWER SERVICES WILL BE CUT AND CAPPED AT THE MAIN INACCORDANCE WITH THE DPW STANDARDS. EXISTING GAS, ELECTRICAL AND TELEPHONE SERVICES WILL BE REMOVEDPER UTILITY COMPANY SPECIFICATIONS. ALL UTILITIES SERVICING BUILDING(S) WILL BE DECOMMISSIONED PRIOR TOTHE COMMENCEMENT OF DEMOLITION ACTIVITIES.3.ANY REUSE OF EXISTING GRANULAR PAVEMENT SUBBASE MATERIAL AND EXCAVATED MATERIAL SHALL BE DETERMINEDBY THE GEOTECHNICAL ENGINEER.4.THE CONTRACTOR SHALL BE RESPONSIBLE FOR MAINTAINING AND PROTECTING ALL EXISTING AND NEW DRAINAGE ANDUTILITIES TO REMAIN AND/OR BE CONSTRUCTED.5.DURING ON-SITE DEMOLITION WORK, STORMWATER RUNOFF SHALL BE CONTROLLED AND DIRECTED TOWARDTEMPORARY SEDIMENT AND EROSION CONTROL MEASURES AS SHOWN ON DWG. C-1.6.SITE CONTRACTOR SHALL REMOVE EXISTING STRUCTURES INDICATED TO BE DEMOLISHED, INCLUDING BUT NOT LIMITEDTO FOUNDATIONS, UTILITIES, BUILDING RELATED APPURTENANCES, LANDSCAPED BEDS, BITUMINOUS PAVEMENT ANDALL OTHER UNSUITABLE MATERIAL TO FIRM NATURAL GROUND AND TO A HORIZONTAL DISTANCE OF TEN (10') FEETBEYOND THE PROPOSED BUILDING LINE.7.IF GROUNDWATER IS ENCOUNTERED DURING THE REMOVAL OF UNSUITABLE MATERIALS, THE CONTRACTOR SHALL LIMITTHE SIZE OF THE EXCAVATION TO THAT WHICH CAN BE ADEQUATELY MANAGED BY THE CONTRACTOR'S CHOSENDEWATERING METHOD.IV.GRADING AND DRAINAGE NOTES:1.SITE GRADING ACTIVITIES SHALL NOT PROCEED UNTIL APPROPRIATE EROSION AND SEDIMENT CONTROL MEASURESHAVE BEEN INSTALLED AND APPROVED BY THE OWNER'S REPRESENTATIVE AND/OR ENGINEER.2.THE EXISTING UTILITIES SHOWN HEREON SHALL BE CONSIDERED APPROXIMATE. THE CONTRACTOR SHALL VERIFY VIATEST PIT EXCAVATION THE LOCATION AND ELEVATION PRIOR TO THE COMMENCEMENT OF CONSTRUCTION. THECONTRACTOR SHALL IMMEDIATELY NOTIFY THE OWNER AND ENGINEER OF DISCREPANCIES ENCOUNTERED IN THEFIELD.3.ALL PROPOSED STORM DRAINAGE PIPES SHALL BE HIGH DENSITY POLYETHYLENE PIPE (HDPE) AND STRUCTURES SHALLBE PRECAST CONCRETE UNLESS NOTED OTHERWISE. HIGH DENSITY POLYETHYLENE PIPE (HDPE) SHALL CONFORM TOAASHTO DESIGNATIONS M294 AND M252, AND SHALL BE N-12 PIPE AS MANUFACTURED BY ADVANCED DRAINAGESYSTEMS (ADS) OR APPROVED EQUAL. PIPE JOINTS SHALL BE INTEGRAL BELL AND SPIGOT, SOIL TIGHT (ST) WITHFACTORY INSTALLED, O-RING RUBBER GASKETS CONFORMING TO ASTM F477.4.ALL CATCH BASINS AND OTHER DRAINAGE STRUCTURES TO BE INSTALLED NEW, REPLACED, OR RECONSTRUCTEDSHALL CONFORM TO CURRENT CONNECTICUT DEPARTMENT OF TRANSPORTATION (CTDOT) STANDARDS. ALL NEWCATCH BASINS SHALL BE EQUIPPED WITH APPROPRIATELY SIZED "TEE" OR HOODS AND A FOUR (4') FOOT SUMP.5.ALL MANHOLES, CATCH BASINS AND PARTICLE SEPARATORS SHALL BE PUMPED "DRY" AND CLEANED AT THE END OFCONSTRUCTION. SEDIMENT AND OTHER POLLUTANTS SHALL BE REMOVED OFF-SITE IN ACCORDANCE WITH ALLFEDERAL, STATE AND LOCAL REQUIREMENTS.6.EXISTING PIPES AND/OR CULVERTS THAT ARE TO REMAIN WITHIN THE LIMIT OF WORK AREA SHALL BE CLEANED OF ANYDEBRIS AND/OR SEDIMENTATION. SEDIMENTATION AND OTHER POLLUTANTS SHALL BE REMOVED OFF-SITE INACCORDANCE WITH ALL FEDERAL, STATE AND LOCAL REQUIREMENTS.7.ALL PROPOSED DRAINAGE STRUCTURES AND PIPES SHALL MEET HEAVY-DUTY TRAFFIC (H20) LOADING AND BEINSTALLED IN ACCORDANCE WITH CTDOT AND/OR MONTVILLE SPECIFICATIONS.8.RIP-RAP SPLASH APRONS SHALL BE PROVIDED AT ALL STORM WATER DISCHARGE POINTS AS SHOWN ON THEDRAWINGS.9.ALL ROOF DRAIN CONNECTIONS SHALL BE INSTALLED TO A POINT TEN (10') FEET FROM THE BUILDING WALL UNLESSOTHERWISE NOTED OR DETAILED.V.UTILITY NOTES:A.GENERAL NOTES1.PRIOR TO THE START OF ANY AUTHORIZED ACTIVITY THE SITE CONTRACTOR SHALL OBTAIN ALL NECESSARY PERMITSFROM THE TOWN OF MONTVILLE. THE CONTRACTOR SHALL OBTAIN FINAL CERTIFICATIONS AND/OR SIGN OFFS UPONMUNICIPALITY AND/OR UTILITY PROVIDER ACCEPTANCE OF WORK WITH COPIES OF FINAL ACCEPTANCE DOCUMENTATION PROVIDED TO THE OWNER.2.THE SITE CONTRACTOR IS RESPONSIBLE FOR OBTAINING AND PAYING FOR ALL PERMITS AND/OR CONNECTION FEESREQUIRED FOR THE INSTALLATION OF ALL SITE UTILITIES.3.DUE TO THE SCALE OF THE SITE WORK DRAWINGS, EXACT LOCATION OF UTILITY STUBS FOR BUILDING CONNECTIONSSHALL BE VERIFIED WITH THE BUILDING DRAWINGS. SERVICE STUBS TO THE BUILDINGS SHALL BE INSTALLED TO A POINTTEN FEET (10') FROM THE BUILDING WALL UNLESS OTHERWISE NOTED OR DETAILED AND SHALL BE PROVIDED WITH ATEMPORARY PLUG AT END.4.ALL UTILITIES, PIPE MATERIALS, STRUCTURES, AND INSTALLATION METHODS, SHALL CONFORM TO THE TOWN OFMONTVILLE'S DPW/ENGINEERING DEPARTMENT STANDARDS AND REQUIREMENTS, UNLESS OTHERWISE NOTED ORDETAILED.5.DIMENSIONS ARE SHOWN TO CENTERLINE OF PIPE OR FITTING.6.UTILITY CONTRACTOR MUST BE LICENSED TO PERFORM WORK IN THE MUNICIPALITY.7.ALL REQUIRED UTILITY CROSSING ENCASEMENTS (CONCRETE) SHALL EXTEND TEN FEET (10') FROM EITHER SIDE OF THECROSSING.8.EXISTING STRUCTURES, LIGHT POLE BASES, CONDUIT AND FIXTURES TO BE REMOVED ARE TO BE DISPOSED OFOFF-SITE IN ACCORDANCE WITH ALL FEDERAL, STATE AND LOCAL REGULATIONS.9.EXISTING UTILITY CASTINGS INDICATED TO REMAIN SHALL BE RESET TO FINISHED GRADE AS REQUIRED AND SHOWN ONDWG. C-2 GRADING AND DRAINAGE PLAN, AND C-3 UTILITY PLAN.10.DETECTABLE WARNING TAPE SHALL BE INSTALLED A MINIMUM ONE (1') FOOT ABOVE THE UTILITY IN ACCORDANCE WITHTHE APPROPRIATE UTILITY COMPANY'S REQUIREMENTS.B.WATER NOTES1.ALL WATER MAIN APPURTENANCES, MATERIALS, METHODS OF INSTALLATION AND TESTING REQUIREMENTS SHALL MEETOR EXCEED THE TOWN OF MONTVILLE'S WATER DEPARTMENT'S STANDARDS.2.ALL WATER MAINS SHALL BE INSTALLED WITH A MINIMUM OF 5'-0" AND MAXIMUM OF 6'-0" OF COVER EXCEPT AS NOTEDOR DETAILED OTHERWISE. GREATER DEPTHS ARE PERMITTED WHERE REQUIRED TO AVOID CONFLICTS WITH OTHERUTILITIES. DETECTABLE WARNING TAPE TO BE INSTALLED ABOVE THE WATER MAIN IN ACCORDANCE WITH THE WATERDEPARTMENT'S REQUIREMENTS.3.GENERALLY, WATER MAIN FITTINGS IDENTIFIED ON THIS DRAWING ARE SHOWN FOR INSTALLATION LOCATIONPURPOSES. THE CONTRACTOR SHALL NOTE THAT NOT ALL FITTINGS ARE NOTED, SHOWN OR INDICATED.4.ALL POTABLE WATER MAINS 3" OR LARGER SHALL BE CEMENT LINED DUCTILE IRON PIPE CLASS 52 AND SHALL BEINSTALLED WITH APPROPRIATELY SIZED FITTINGS AND GATE VALVES. FITTINGS SHALL BE MECHANICAL JOINT, DUCTILEIRON CLASS 350 WITH RESTRAINT DEVICES (MEGALUG) AS MANUFACTURED BY EBAA IRON, INC. OR APPROVED EQUAL.5.DOMESTIC WATER SERVICES 2-1/2" AND SMALLER SHALL BE TYPE K COPPER TUBING AND SHALL BE INSTALLED WITHAPPROPRIATELY SIZED CORPORATION STOP, APPROVED SADDLE, CURB STOP AND BOX.6.A MINIMUM DISTANCE OF TEN (10) FEET CLEAR HORIZONTALLY SHALL BE MAINTAINED BETWEEN SANITARY SEWER MAINSAND WATER MAINS. WHENEVER CONDITIONS PREVENT A LATERAL SEPARATION OF TEN (10) FEET TO A WATER MAIN, THEWATER MAIN SHALL BE LAID IN A SEPARATE TRENCH AND THE ELEVATION OF THE CROWN OF THE SEWER SHALL BE ATLEAST EIGHTEEN (18) INCHES BELOW THE INVERT OF THE WATER MAIN. A MINIMUM OF EIGHTEEN (18") INCHES VERTICALCLEARANCE SHALL BE MAINTAINED WHERE WATER MAINS CROSS STORM DRAIN LINES.7.MAINTAIN A MINIMUM SEPARATION OF THREE FEET (3') BETWEEN GAS AND WATER MAINS (MEASURED FROM THECENTER OF THE PIPE).8.ALL HYDRANTS SHALL MEET THE TOWN OF MONTVILLE'S WATER, UTILITY, AND FIRE DEPARTMENT REQUIREMENTS ANDSHALL BE INSTALLED IN ACCORDANCE WITH THE WATER AND FIRE DEPARTMENT REQUIREMENTS9.ALL NEW GATE VALVES INSTALLED FOR THIS PROJECT SHALL OPEN AS REQUIRED BY THE TOWN OF MONTVILLE.10.ALL WATER MAIN FITTINGS, TEES, HYDRANTS, ETC. SHALL BE RESTRAINED WITH APPROPRIATELY SIZED THRUST BLOCKSOR MECHANICAL JOINT RESTTRAINTS.11.WATER METERS AND BACK FLOW PREVENTERS SHALL BE LOCATED WITHIN THE BUILDING. ALL BACKFLOW PREVENTERSSHALL BE REGISTERED WITH THE DEPARTMENT OF PUBLIC WORKS.12.PRESSURE AND LEAKAGE TEST, DISINFECTION AND FLUSHING SHALL BE IN ACCORDANCE WITH THE TOWN'S WATERUTILITY REQUIREMENTS. IN THE ABSENCE OF STANDARDS, THEY SHALL CONFORM TO THE REQUIREMENTS IN THESITEWORK SPECIFICATIONS. THE CONTRACTOR SHALL BE RESPONSIBLE FOR ALL COSTS IN CONNECTION WITH UTILITYTESTS, FLUSHING AND INSPECTIONS AS REQUIRED BY THE TOWN'S WATER UTILITY. COPIES OF TEST RESULTS SHALL BESUBMITTED TO THE WATER DEPARTMENT.C.SEWER NOTES13.ALL GRAVITY SEWER PIPE SHALL BE POLYVINYL CHLORIDE PIPE (P.V.C.), S.D.R. 35 AND SHALL CONFORM WITHASTM-D3034 UNLESS NOTED OTHERWISE.14.WHERE SANITARY SEWERS CROSS WATER MAINS, THE SEWER SHALL BE LAID AT SUCH AN ELEVATION THAT THE CROWNOF THE SEWER IS AT LEAST EIGHTEEN INCHES BELOW THE INVERT OF THE WATER MAIN. IF THE ELEVATION OF THESEWER CANNOT BE VARIED TO MEET THIS REQUIREMENT, THE WATER MAIN SHALL BE RELOCATED TO PROVIDE THISSEPARATION OR CONSTRUCTED WITH MECHANICAL JOINT PIPE FOR A DISTANCE OF TEN FEET (10') ON EACH SIDE OFTHE SEWER. ONE FULL LENGTH OF WATER MAIN SHALL BE CENTERED OVER THE SEWER SO THAT BOTH JOINTS WILL BEAS FAR FROM THE SEWER AS POSSIBLE. IF MECHANICAL JOINT PIPE IS NOT USED THEN BOTH THE WATER MAIN ANDSANITARY SEWER SHALL BE ENCASED IN CONCRETE FOR A MINIMUM DISTANCE OF TEN (10') FEET FROM THE CROSSINGPOINT OF THE OTHER PIPE AS MEASURED NORMALLY FROM ALL POINTS ALONG THE PIPE.15.ALL SEWER MAIN APPURTENANCES, MATERIALS, METHODS OF INSTALLATION AND TESTING REQUIREMENTS SHALL MEETOR EXCEED THE TOWN'S SEWER DEPARTMENT'S STANDARDS.16.SANITARY SEWER SERVICE TO THE BUILDING WILL END TEN FEET (10') OUTSIDE THE BUILDING LIMITS AS SHOWN ON THEPLANS AND SHALL BE PROVIDED WITH A TEMPORARY PLUG AT THE END.17.DETECTABLE WARNING TAPE TO BE INSTALLED A MINIMUM ONE (1') FOOT ABOVE SEWER MAIN AND IN ACCORDANCEWITH THE MUNICIPALITY'S SEWER DEPARTMENT'S REQUIREMENTS.18.ALL SANITARY SEWER MANHOLE FRAME AND COVERS ARE TO BE HEAVY DUTY DESIGNED FOR H-20 LOADING.19.ALL NEW SEWER MAINS AND ASSOCIATED MANHOLES SHALL BE TESTED FOR WATER TIGHTNESS IN THE PRESENCE OFTHE AUTHORITY HAVING JURISDICTION.D.GAS NOTES1.THE CONTRACTOR IS RESPONSIBLE FOR THE LAYOUT, EXCAVATION AND BACKFILLING OF GAS MAIN TRENCH.EXCAVATION AND BACKFILLING REQUIREMENTS SHALL BE PERFORMED IN ACCORDANCE WITH THE GAS COMPANYREQUIREMENTS.2.THE GAS TRENCH SHALL BE LAID OUT SO AS TO PROVIDE A MINIMUM OFFSET OF THIRTY-SIX (36) INCHES FROM OTHERUTILITIES. NO TRENCHING SHALL BE STARTED UNTIL AN ON-SITE MEETING HAS BEEN HELD BETWEEN THE EXCAVATINGCONTRACTOR AND GAS COMPANY PERSONNEL. PRIOR TO THE MEETING, THE EXCAVATING CONTRACTOR MUST NOTIFYDIG SAFE OF THE PROPOSED WORK. THE FOLLOWING SHALL BE CONFIRMED AT THE MEETING:A. THE EXCAVATING CONTRACTOR MUST PAD THE TRENCH BOTTOM WITH SIX (6) INCHES OF SAND AND MUSTPROVIDE SAND SUFFICIENT TO PROVIDE A MINIMUM OF (6) INCHES OF COVER ABOVE THE GAS PIPE.B. THE ROUTE OF THE TRENCH.C. MINIMUM FOOTAGE OF THE TRENCH TO BE OPENED BEFORE GAS COMPANY MOBILIZES CREWS TO START INSTALLING THE GAS PIPE.D. MINIMUM TWO (2) WEEK NOTICE REQUIRED FOR GAS COMPANY TO START INSTALLING PIPE.VI. PARKING AND TRAFFIC CONTROL NOTES:1.ACCESSIBLE PARKING SPACES SHALL CONFORM TO THE REQUIREMENTS OF THE AMERICANS WITH DISABILITIES ACT(A.D.A.) ACCESSIBILITY GUIDELINES AND THE LATEST EDITIONS UNLESS OTHERWISE NOTED.3.VAN ACCESSIBLE HANDICAP PARKING SPACES SHALL BE SIGNED AS "VAN ACCESSIBLE" PER A.D.A. (SEE 4.1.2.5B).4.ALL PROPOSED CURBING SHALL BE BITUMINOUS BERM CURBING, UNLESS OTHERWISE NOTED. ALL SIDEWALKS SHALL BEMONOLITHIC CURB AND SIDEWALK.5.ALL PAVEMENT STRIPING SHALL BE PAINTED WITH 2 COATS OF PAINT. PARKING STALLS SHALL BE MARKED WITH FOUR(4") INCH WIDE PAINTED LINES.6.PARKING AND TRAFFIC CONTROL PLAN IS SCHEMATIC AND FOR LOCATION OF MARKINGS ONLY. SPECIFIC DETAILS OFPAVEMENT MARKINGS ARE PROVIDED AS PART OF THIS PLAN SET.7.THE CONTRACTOR SHALL REFER TO THE ARCHITECTURAL/BUILDING PLANS FOR EXACT BUILDING LOCATIONS, BUILDINGDIMENSIONS, EXACT UTILITY ENTRANCE LOCATIONS, TRUCK DOCKS, BUILDING SIDEWALKS AND DOOR LOCATIONS.8.FOR PAVEMENT SECTION SEE DWG. C-8.9.ALL LIMITS OF PAVEMENT SHALL BE CURBED UNLESS NOTED OR INDICATED OTHERWISE.10.THE CONTRACTOR SHALL ADJUST ALL UTILITY CASINGS TO THE PROPER LINE AND ELEVATION PRIOR TO THEPLACEMENT OF THE TOP COURSE OF PAVEMENT. NECESSARY ADJUSTMENTS SHALL BE MADE TO CASTINGS IFREQUIRED, TO MAKE THEM FLUSH WITH FINISHED GRADE. NO DEPRESSIONS OR MOUNDS TO ACCOMMODATE CASTINGSWILL BE PERMITTED.11.ALL ACCESSIBLE CURB RAMPS SHALL BE CONSTRUCTED OF CEMENT CONCRETE AND COMPLY WITH A.D.A.REQUIREMENTS.LEFT LANEMUSTTURN LEFTR1-130"30"CHANNEL7'-0"R3-7(L)30"30"CHANNEL7'-0"SIGNNUMBERSIGNSIZE OF SIGNWIDTHHEIGHTBACKGROUNDMOUNTTYPEMOUNTSIZESTOPRIGHT LANEMUSTTURN RIGHTR3-7(R)30"30"CHANNEL7'-0"LEGENDBORDERREDWHITEWHITEWHITEBLACKBLACKWHITEBLACKBLACKTRAFFIC CONTROL SIGN SCHEDULEVANACCESSIBLECHANNEL7'-0"12"6"CHANNEL6'-6"12"18"BLUEWHITEBLUEWHITE--R7-8R7-8ADrawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Main\24029_N-1 Notes and Legends.dwg Sep 25, 2024 - 16:10pm 24029HORIZON VIEWMONTVILLE, CT20 AVON MEADOW LANEAVON, CT 06001DRAWING NUMBER:PROJECT NUMBER:Copyright © 2024 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS80 MONTVALE AVENUE , SU ITE 201 STONEHAM, MA 02180PHONE: 781 .279.0180 RJOCONNELL.COM NO.DATEREVISIONDRAWING NAME:PREPARED FOR:DESIGNED BY:DRAWN BY:REVIEWED BY:DATE:PROJECT NAME:SCALE:PREPARED BY:SEAL:NO.DATEREVISION 1.09/25/2024SUBMITTED TO INLAND WETLANDS COMMISSIONVISITORPARKINGONLYX-1CHANNEL7'-0"12"18"WHITEBLACKBLACK TVAN VAN4 STORIESWITH 57 UNITSFFE=152.50GMMM18" D18" DCB-5R=148.50I=146.00(DMH-3)12" D151.0515" D 151.25151.05APPROXIMATELY 9,770 SFOF 50' UPLAND REVIEWAREA BEING DISTURBEDTC=152.40BC=152.00152.50TC=153.70BC=153.20TW=154.50BW=149.50CB-1R=151.50I=148.50(DMH-1)12" DTC=153.75BC=153.25DMH-OS2 W/ DEEP SUMPR=152.00I=148.30(DMH-OS1)I=148.20(FES-1)TW=155.50BW=153.20TW=155.80BW=155.50TW=154.25BW=149.50TW=153.75BW=153.00DMH-OS1W/ DEEP SUMPR=153.10I=149.40(HW-1)I=149.30(DMH-OS2)TW=149.30BW=MATCH EX. (±144.0)TW=150.00BW=MATCH EX. (±144.0)TW=150.25BW=MATCH EX. (±144.0)TW=150.75BW=MATCH EX. (±144.0)TW=151.25BW=MATCH EX. (±144.0)TW=151.75BW=MATCH EX. (±144.0)TW=154.50BW=MATCH EX. (±144.0)TW=150.250BW=MATCH EX. (±144.0)152.50152.30155'12" DTW=150.50BW=MATCH EX. (±144.0)TW=150.50BW=150.0049'TC=152.00BC=151.50SUBSURFACEINFILTRATIONBASINBOTTOM STONE = 142.00BOTTOM PIPE = 142.50TOP PIPE = 149.50TOP STONE = 150.005 ROW OF 84"PERFORATED CMP PIPEON-SITE DETENTION BASINCB-2R=151.50I=148.10(DMH-1)DMH-1R=151.60I=148.00(CB-1)I=148.00(CB-2)I=147.90(CDS-1)CDS-1R=151.90I=147.60(DMH-1)I=147.60(SSIS-I1)CB-7R=151.25I=147.25()CB-3R=150.50I=147.50(DMH-2)CB-4R=150.75I=147.50(DMH-2)DMH-2R=151.50I=147.20(CB-3)I=147.20(CB-4)I=147.10(DMH-3)DMH-3R=150.20I=145.40(CB-5)I=146.40(DMH-2)I=145.30(CDS-2)CDS-2R=150.60I=144.60(DMH-3)I=144.60(CB-6)I=144.60(SSIS-I2)CB-6R=149.75I=145.00(CDS-2)OCS-1ORIFICE WITH TRASH RACK = 146.0WEIR = 150.00PIPE = 146.00151.00TC=151.70BC=151.20TC=151.70BC=151.20152.50152.40TC=152.40BC=151.90TC=152.40BC=151.90TC=151.50BC=151.00TC=151.50BC=151.00TC=151.95BC=151.45TC=151.75BC=151.25151.85152.05151.8018" DPERMANENTDISTURBEDAREA = ±636 SF153.40153.40SSIS-O1 LEVEL SPREADERWITH CURB EDGE(MIN. 55'L)OCS-OFFSITE20"X12" ORIFICE WITH TRASH RACK = 148.0WEIR = 150.00PIPE = 146.40TEMPORARY DISTURBEDAREA = ±432 SF151.204' HIGH CHAIN LINKFENCE WITH ACCESSGATESTW=149.00BW=MATCH EX. (±144.0)TW=151.75BW=MATCH EX. (±144.0)OFFSITEDETENTIONBASIN151.502: 1 1. 5 : 12:13:13:13:12:1OS-DMH3R=146.20I=142.40(OS-DMH2)I=142.30(OS-FES1)OS-DMH1R=147.80I=145.90(OCS-OFFSITE)I=145.80(OS-DMH2)SSI-OCS-1R=152.00I=146.00(SSI-OUT 1)ORIFICE=146.00WEIR=149.50I=146.00(FES-2)SSI-OCS-2R=152.00I=146.00(SSI-OUT 2)ORIFICE=146.00WEIR=149.50I=146.00(FES-3)CATCH BASIN/ SEDIMENTTRAP AND BEEHIVE FRAMEAND GRATE W/ 4 FT SUMPR=149.00I=149.5018" DFES-1I=148.00(DMH-OS2)FES-2I=146.00(SSI-OCS-1)RIP RAP APRON (SEE DWG. C-7)FES-3I=146.00(SSI-OCS-2)RIP RAP APRON (SEE DWG. C-7)OS-FES1I=142.00(OS-DMH3)SEE DWG. C-6 FOR LEVEL SPREADER DETAILS12" D12" D12" D12" D18" D12" D18 " D 18" DOS-DMH2R=151.25I=143.60(OS-DMH1)I=143.60(OCS-1)I=143.50(OS-DMH3)18" D153 1541 5 1 151151 150 149 151150150 151151150 153 152 151151 151 1511541521521531551531521531521 5 1 152 15 2 152 149148147146 152151.5151.515215215 1 15015215315 3 152150155154 15315 3 145 148151150146 154158160158156154152158156154 16216 0 16 2 156150 153153 152 153 153 150 150148 148 146 146147 148 149 150 151 153153 153153 153 150 148151 151 154155156157158159160161162163164165155 156 157 158 158 160 162148146143144143144 165155 156158160162164159157156155 148 30" D30" D18" D18" DRIP RAP APRON(SEE DWG. C-7TYP.)142152 150 152 150 148 Drawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Main\24029_C-2 Grading and Drainage Plan.dwg Sep 25, 2024 - 16:25pm 24029HORIZON VIEWMONTVILLE, CT20 AVON MEADOW LANEAVON, CT 06001DRAWING NUMBER:PROJECT NUMBER:Copyright © 2024 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS80 MONTVALE AVENUE , SU ITE 201 STONEHAM, MA 02180PHONE: 781 .279.0180 RJOCONNELL.COM NO.DATEREVISIONDRAWING NAME:PREPARED FOR:DESIGNED BY:DRAWN BY:REVIEWED BY:DATE:PROJECT NAME:SCALE:PREPARED BY:SEAL:NO.DATEREVISION 1.09/25/2024SUBMITTED TO INLAND WETLANDS COMMISSIONC-2GRADING ANDDRAINAGE PLANMAP/RWSWJHBPD/RWS09/25/20241" = 30'0GRAPHIC SCALE IN FEET30153060PROPOSED CONTOUR ELEVATIONSPOT ELEVATIONDRAIN LINEDRAIN MANHOLELEGENDCATCH BASINDOUBLE CATCH BASINAREA DRAINDRAIN CLEAN OUTFLARED END SECTION33HEADWALLRIP RAP SPLASH PADROOF DRAINRDTRENCH DRAINBORINGTEST PITUNDISTURBED BUFFERRJOCNNOTES:1.SLOPES STEEPER THAN 3:1 REQUIRE EROSIONCONTROL MATTING FOR STABILIZATION.2.SEE DRAWING N-1 FOR GENERAL NOTES,EROSION CONTROL NOTES, DEMOLITION NOTES,GRADING & DRAINAGE NOTES, UTILITY NOTES,AND PARKING AND TRAFFIC CONTROL SIGNSCHEDULE.3.SEE DRAWING C-5 THROUGH C-10 FOR DETAILS. C-5 DEMOLITION AND EROSION CONTROL DETAILS RWS WJH BPD/RWS 09/25/2024 NOT TO SCALE Drawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Main\24029_C-5 Demolition and Erosion Control Details.dwg Sep 25, 2024 - 16:11pm24029 HORIZON VIEW MONTVILLE, CT 20 AVON MEADOW LANE AVON, CT 06001 DRAWING NUMBER: PROJECT NUMBER: Copyright © 2024 by R.J. O'Connell & Associates, Inc. RJO'CONNELL & ASSOCIATES, INC. CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS 80 MONTVALE AVENUE, SUITE 201 STONEHAM, MA 02180 PHONE: 781.279.0180 RJOCONNELL.COM NO.DATEREVISIONDRAWING NAME: PREPARED FOR: DESIGNED BY: DRAWN BY: REVIEWED BY: DATE: PROJECT NAME: SCALE: PREPARED BY: SEAL:NO.DATEREVISION1.09/25/2024SUBMITTED TO INLAND WETLANDS COMMISSIONSCALE: N.T.S. CONSTRUCTION ENTRANCE PERSPECTIVE VIEW 20' (MI N' ) 50' ( M I N . ) ROAD W A Y/ A C C E S S D R I V E FILTER FABRIC MIRAFI 140N (PLACED BENEATH FULL WIDTH AND FULL LENGTH OF CONSTRUCTION ENTRANCE) CRUSHED STONE (3"± IN SIZE) PER ASTM AGGREGATE GRADE NO. 1 6" MINIMUM THICKNESS NOTES: 1.ENTRANCE SHALL BE MAINTAINED IN A CONDITION THAT PREVENTS TRACKING OF SEDIMENT ONTO PUBLIC RIGHT-OF-WAY. 2.WHEN THE ENTRANCE PAD BECOMES INEFFECTIVE, THE STONE SHALL BE REMOVED WITH THE COLLECTED SOIL MATERIAL, REGRADED, STABILIZED AND THE CONSTRUCTION ENTRANCE RECONSTRUCTED. COMPACTED SUBGRADE COMPACTED SUBGRADE SCALE: N.T.S. NOTES: 1.PREPARE SOIL BEFORE INSTALLING BLANKETS, INCLUDING ANY NECESSARY APPLICATION OF LIME, FERTILIZER, AND SEED. NOTE: WHEN USING CELL-O-SEED DO NOT SEED PREPARED AREA. CELL-O-SEED MUST BE INSTALLED WITH PAPER SIDE DOWN. 2.BEGIN AT THE TOP OF THE SLOPE BY ANCHORING THE BLANKET IN A 6" (15cm) WIDE TRENCH WITH APPROXIMATELY 12" (30cm) OF BLANKET EXTENDED BEYOND THE UP-SLOPE PORTION OF THE TRENCH. ANCHOR THE BLANKET WITH A ROW OF STAPLES/STAKES APPROXIMATELY 12" (30cm) APART IN THE BOTTOM OF THE TRENCH. BACKFILL AND COMPACT THE TRENCH AFTER STAPLING. APPLY SEED TO COMPACTED SOIL AND FOLD REMAINING 12" (30cm) PORTION OF THE BLANKET BACK OVER SEED AND COMPACTED SOIL. SECURE BLANKET OVER COMPACTED SOIL WITH A ROW OF STAPLES/STAKES SPACED APPROXIMATELY 12" (30cm) APART ACROSS THE WIDTH OF THE BLANKET. 3.ROLL THE BLANKETS (A.) DOWN OR (B.) HORIZONTALLY ACROSS THE SLOPE. BLANKETS WILL UNROLL WITH THE APPROPRIATE SIDE AGAINST THE SOIL SURFACE. ALL BLANKETS MUST BE SECURELY FASTENED TO SOIL SURFACE BY PLACING STAPLES/STAKES IN APPROPRIATE LOCATIONS AS SHOWN IN THE STAPLE PATTERN GUIDE. WHEN USING OPTIONAL DOT SYSTEM, STAPLES/STAKES SHOULD BE PLACED THROUGH EACH OF THE COLORED DOTS CORRESPONDING TO THE APPROPRIATE STAPLE PATTERN. 4.THE EDGES OF PARALLEL BLANKETS MUST BE STAPLED WITH APPROXIMATELY 2"-5" (5cm-12.5cm) OVERLAP DEPENDING ON BLANKET TYPE. TO ENSURE PROPER SEAM ALIGNMENT, PLACE THE EDGE OF THE OVERLAPPING BLANKET (BLANKET BEING INSTALLED ON TOP) EVEN WITH THE COLORED SEAM STITCH ON THE PREVIOUSLY INSTALLED BLANKET. 5.CONSECUTIVE BLANKETS SPLICED DOWN THE SLOPE MUST BE PLACED END OVER END (SHINGLE STYLE) WITH AN APPROXIMATE 3" (7.5cm) OVERLAP. STAPLE THROUGH OVERLAPPED AREA, APPROXIMATELY 12" (30cm) APART ACROSS ENTIRE BLANKET WIDTH. 6.EROSION CONTROL BLANKET SHALL BE BIODEGRADABLE DOUBLE NET STRAW AS MANUFACTURED BY ACF ENVIRONMENTAL OR APPROVED EQUAL. 7.IN LOOSE SOIL CONDITIONS, THE USE OF STAPLE OR STAKE LENGTHS GREATER THAN 6" (15cm) MAY BE NECESSARY TO PROPERLY ANCHOR THE BLANKETS. EROSIONAL CONTROL BLANKET DETAIL (FOR SLOPE PROTECTION) 2"-5" (5cm-12.5cm)6"(15cm)12" (30cm) 6" (15 cm) 3" (7.5cm) 2 4 3B 3A 5 1 1 DUMP STRAPS (2 EACH) SCALE: N.T.S. TYPICAL FILTER BAG DETAIL NOTES: 1.INSTALL SILT SACK IN ACCORDANCE WITH MANUFACTURER'S INSTRUCTIONS. 2.SILT SACK SHALL BE INSPECTED AND CLEANED PER THE INSPECTION REQUIREMENTS AS OUTLINED IN THE STORMWATER POLLUTION PREVENTION PLAN (SWPPP). IN THE ABSENCE OF A SWPPP, SILT SACK SHALL BE CLEANED WHEN THE EXPANSION RESTRAINT CORD IS NO LONGER VISIBLE. 3.REMOVE SILT BAG PER MANUFACTURER'S INSTRUCTIONS. SILT BAG WOVEN POLYPROPYLENE GEOTEXTILE, HI-FLOW (TYPE A) SILK SACK AS MANUFACTURED BY ACF ENVIRONMENTAL OR APPROVED EQUAL EXPANSION RESTRAINT (1/4" NYLON ROPE, 2" FLAT WASHERS) RESTRAINT CORD HEAVY DUTY, CAST IRON FRAME AND GRATE SCALE: N.T.S. TYPICAL SINGLE ROW WATTLE INSTALLATION DETAIL 4'-0" MAX NOTES: 1.WATTLES SHALL BE A MACHINE PRODUCED TUBE THAT IS 100% STRAW FIBER THAT IS CERTIFIED WEED FREE FORAGE. 2.THE NETTING SHALL CONSIST OF SEAMLESS HIGH DENSITY POLYETHYLENE AND ETHYL VINYL ACETATE AND CONTAIN ULTRA VIOLET INHIBITORS. 3.WATTLE BARRIER TO BE INSPECTED PER THE INSPECTION REQUIREMENTS AS OUTLINED IN THE STORMWATER POLLUTION PREVENTION PLAN (SWPPP). IN THE ABSENCE OF A SWPPP, INSPECTIONS SHALL OCCUR WEEKLY AND AFTER EACH RAINFALL EVENT GREATER THAN 0.25 INCHES. 4.DAMAGED AND/OR DECOMPOSED WATTLES SHALL BE REPLACED IMMEDIATELY. TOP VIEW ELEVATION SECTION A-A A A 9" WATTLE BUTT WATTLE ENDS TIGHT, NO GAPS BUTT WATTLES TOGETHER 114" x 114" x 3' (NOMINAL) OAK OR HARDWOOD STAKE 114" x 114" x 3' (NOMINAL) OAK OR HARDWOOD STAKE (AS NEEDED) 11 4" x 11 4" x 3' (NOMINAL) OAK OR HARDWOOD STAKE (AS NEEDED) WATTLE TO BE SET FLUSH WITH GROUND (NO DAYLIGHT)24"TYPICAL CATCH BASIN WATTLE INLET PROTECTION DETAIL SCALE: N.T.S. NOTES: 1.WATTLES SHALL BE 12" DIAMETER, MACHINE PRODUCED THAT IS 100% STRAW FIBER AND CERTIFIED WEED FREE FORAGE. THE NETTING SHALL CONSIST OF SEAMLESS HIGH DENSITY POLYETHYLENE AND ETHYL VINYL ACETATE AND CONTAIN ULTRA VIOLET INHIBITORS. 2.WATTLES SHALL BE PLACED IN A ROW WITH THE ENDS TIGHTLY ABUTTING THE ADJACENT WATTLES. 3.WATTLES SHALL BE SECURELY ANCHORED IN PLACE BY STAKES DRIVEN THROUGH THE WATTLES. 4.WATTLES TO BE INSPECTED PER THE INSPECTION REQUIREMENTS AS OUTLINED IN THE STORMWATER POLLUTION PREVENTION PLAN (SWPPP). IN THE ABSENCE OF A SWPPP, INSPECTIONS SHALL OCCUR WEEKLY AND AFTER EACH RAINFALL EVENT GREATER THAN 0.25 INCHES. SEDIMENT DEPOSITS MUST BE REMOVED WHEN DEPOSITS REACH ONE HALF THE HEIGHT OF THE BARRIER. 5.THIS DETAIL IS TO BE USED WHEN PARKING AREAS ARE AT SUBGRADE ELEVATION DRAIN INLET FRAME AND GRATE 11 4"x11 4"x3' (NOMINAL) OAK OR HARDWOOD STAKE (TYP.) WATTLE SEAM 12" Ø WATTLE SILTATION FENCE DETAIL FINISH GRADE SCALE: N.T.S. TYPICAL TEMPORARY DRAINAGE SWALE DETAIL 3:1 SLOPE (TYP.)6" MINUM 12" MAXIMUM ℄ SWALE SUBGRADE FILL OR EXISTING EARTH 4' (MIN.) STAKED WATTLE BARRIER 40' O.C. (SEE STRAW WATTLE CHECK DAM DETAIL). SCALE: N.T.S. TEMPORARY RISER OUTLET DETAIL1'-0"MAX. SEDIMENT STORAGE PERMANENT OUTLET PIPE (SEE DWG. C-2) 3 1 TRASH RACK TOP OF RISER PERFORATED CORRUGATED METAL RISER PIPE (SIZE TO MATCH OUTLET PIPE) TOP OF BERM ELEVATION VARIES (SEE DWG. C-2) BOTTOM BASIN 2" MINUS WASHED CRUSHED STONE 2" MINUS WASHED CRUSHED STONE 90° CORRUGATED METAL ELBOW 50% SEDIMENT CLEAN OUT LEVEL (STAKE IN FIELD) NOTES: 1.PERFORATED CORRUGATED METAL RISER PIPE TO BE WRAPPED WITH FILTER FABRIC (MIRAFI 140N OR APPROVED EQUAL). 2.SEDIMENT BASINSTO BE INSPECTED THROUGHOUT CONSTRUCTION. SCALE: N.T.S. STRAW WATTLE CHECKDAM DETAIL NOTES: 1.STRAW WATTLE CHECK DAMS TO BE SECURED TO THE GROUND WITH 3' LONG GRADE STAKES DRIVEN THROUGH THE WATTLE AND PENETRATING AT LEAST 12-INCHES INTO THE GROUND. STAKES TO BE EXPOSED 3 INCHES (MAX.) ABOVE THE TOP OF THE WATTLE. 2.WATTLES SHALL BE MACHINE-PRODUCED THAT IS 100% STRAW FIBER AND CERTIFIED WEED FREE FORAGE. THE NETTING SHALL CONSIST OF SEAMLESS HIGH DENSITY POLYETHYLENE AND ETHYL VINYL ACETATE AND CONTAIN ULTRA VIOLET INHIBITORS. 3.WATTLES SHALL BE PLACED IN A ROW WITH THE ENDS TIGHTLY ABUTTING THE ADJACENT WATTLE. 40'± O. C . ( T Y P . ) 9-INCH DIAMETER (MIN.) STRAW WATTLE 114"x114"x3' (NOMINAL) OAK OR HARDWOOD STAKE SPACED 4'-0" O.C. (MAX.) SEDIMENT SWALE 2:1150151150146146 147 148148146143144143144148142152150148 C-6DRAINAGEDETAILS IMAP/RWSWJHBPD/RWS09/25/2024NOT TO SCALEDrawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Main\24029_C-6 Drainage Details I.dwg Sep 25, 2024 - 16:20pm 24029HORIZON VIEWMONTVILLE, CT20 AVON MEADOW LANEAVON, CT 06001DRAWING NUMBER:PROJECT NUMBER:Copyright © 2024 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS80 MONTVALE AVENUE , SU ITE 201 STONEHAM, MA 02180PHONE: 781 .279.0180 RJOCONNELL.COM NO.DATEREVISIONDRAWING NAME:PREPARED FOR:DESIGNED BY:DRAWN BY:REVIEWED BY:DATE:PROJECT NAME:SCALE:PREPARED BY:SEAL:NO.DATEREVISION 1.09/25/2024SUBMITTED TO INLAND WETLANDS COMMISSIONCONNECTICUT D.O.T. STANDARD CATCH BASINOUTLET CONTROL STRUCTURE DETAILCMPELEV. 142.00ELEV. 150.00TYPICAL 7' CMP SUBSURFACE INFILTRATION SYSTEMELEV. 149.50NOTE:1.FOR ELEVATIONS SEE GRADING & DRAINAGE PLAN (DWG. C-2)ELEV. 142.501.0'MIN. ATENDSANDSIDES(BOT. OF STONE)MIRAFI 140N FILTER FABRIC OVERSTONE AND PIPE.1 12" TO 2" UNIFORMLY SIZED ANGULARDOUBLE WASHED AASHTO M43 NO. 3 STONEPLACED IN 8" LIFTS AND HAND COMPACTED.SEE PAVEMENTSECTION DETAIL(DWG. C-9)WASHED STONETO TOP OF PIPE(TOP OF STONE)(TOP OF PIPE)UNDISTURBEDMATERIALAT GRADEPARKING ELEVATIONVARIES1'-0" FILTERFABRICPIPE SIZE 84" DIA.CMP (TYP.)PERFORATED 84"CMP PIPE (TYP.)SSI = 3'-0" (TYP)(BOT OF PIPE)PLAN VIEW B-BN.T.S.FIBERGLASS SEPARATIONCYLINDER AND INLETCENTER OF CDS STRUCTURE, SCREEN ANDSUMP OPENINGPVC HYDRAULIC SHEARPLATE1'-8" [507](2'-0" [610])1'-4" [406](4'-2" [1269])FIBERGLASS SEPARATIONCYLINDER AND INLETSOLIDS STORAGE SUMPSEPARATIONSCREENINLET PIPE(MULTIPLE INLET PIPESMAY BE ACCOMMODATED)OUTLET PIPEPVC HYDRAULICSHEAR PLATE(4'-0" [1219])MAY VARYFLOWOIL BAFFLE SKIRTCONTRACTOR TO GROUTTO FINISHED GRADEGRADERINGS/RISERSAA36" [914] I.D. MANHOLESTRUCTURETOP SLAB ACCESS(SEE FRAME AND COVERDETAIL)VARIES+/-135°MAX.FLOW+/-65°MAX.PERMANENT POOLELEV.CDS UNIT - WATER QUALITY UNIT - CDS-1515LEVEL SPREADER DETAILTC 144.00OS-DMH3R=146.20I=143.60(OS-DMH1)I=143.10(OS-FES-1)OS-FES1I=142.00(OS-DMH3)PROPOSED CURB LEVELSPREADER (SEE NOTE 1)OS-DMH2R=151.25I=143.60(OS-DMH1)I=143.10(OS-FES-1)OCS-1ORIFICE WITH TRASH RACK = 146.0WEIR = 150.00PIPE = 146.00PROPOSED CURBTC 144.0OUTLET CONTROL STRUCTURE (OCS) FOR BASINS8BOTTOM OF LEVEL SPREADERELEV. = 142.0EMERGENCY SPILLWAYELEV. = 151.20MATCH EXISTINGGRADE21EXISTING VEGETATION TO REMAINAND BE PROTECTED THROUGHOUTCONSTRUCTIONSECTIONNOTE:1.LEVEL SPREADER MINIMUMLENGTH = 56 FTCONCRETECOMPACTED SUBGRADEEROSION CONTROL MATTING(SEE DWG. C-5)151.20X C-7DRAINAGEDETAILS IIMAP/RWSWJHBPD/RWS09/25/2024NOT TO SCALEDrawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Main\24029_C-7 Drainage Details II.dwg Sep 25, 2024 - 16:15pm 24029HORIZON VIEWMONTVILLE, CT20 AVON MEADOW LANEAVON, CT 06001DRAWING NUMBER:PROJECT NUMBER:Copyright © 2024 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS80 MONTVALE AVENUE , SU ITE 201 STONEHAM, MA 02180PHONE: 781 .279.0180 RJOCONNELL.COM NO.DATEREVISIONDRAWING NAME:PREPARED FOR:DESIGNED BY:DRAWN BY:REVIEWED BY:DATE:PROJECT NAME:SCALE:PREPARED BY:SEAL:NO.DATEREVISION 1.09/25/2024SUBMITTED TO INLAND WETLANDS COMMISSION PRECAST CONCRETE DRAIN MANHOLE (DMH)NOTE:MANHOLES AND ALL COMPONENT PARTS SHALL BE OFSIZE, STRENGTH AND CONFIGURATION AS SHOWNEXCEPT THAT TOP SLABS MAYBE SUBSTITUTED FORECCENTRIC CONE SECTIONS. MANHOLES SHALL BE ANASSEMBLY OF REINFORCED, PRECAST CONCRETE BASERISER SECTIONS PER ASTM C478 OR MONOLITHICALLY,CAST-IN-PLACE REINFORCED CONCRETE. APPROVEDMANHOLE STRUCTURE SHALL BE DESIGNED ANDCONSTRUCTED TO MEET OR EXCEED H20 LOADING ANDPREVENT LEAKAGE IN EXCESS OF ONE (1) GALLON PERDAY PER VERTICAL FOOT OF MANHOLE.ECCENTRIC CONE SECTION 26"-48" RISER SECTION(S) BASE SECTION 8"24"DIA.OPENING* DMH DIA. ARE FOR STRAIGHTTHROUGH PIPE. DIAMETER MAYHAVE TO BE INCREASED TOACCOMMODATE ADDITIONALPIPES CONNECTING TOMANHOLE AT ANGLES48"DIA. (MIN)** DMH DIAMETER48" FOR PIPES UP TO 30"60" FOR 36" AND 42" PIPES72" FOR 48" PIPES84" FOR 54" AND 60" PIPES96" FOR 66" AND 72" PIPES5" (48" DIA.) 6"(60" DIA.) 6" (72"DIA.) 7" (84" DIA.)8" (96" DIA.)FLOWSECTIONADJUST TO GRADE WITH SEWER BRICKPER ASTM C32, GRADE SS SET IN FULLMORTAR BED OR PRECAST CONCRETERINGS MAX 12" ADJUSTMENT24" DIA. MANHOLE FRAME & COVER BYEAST JORDAN IRON WORKS CAT. NO.LA264-000 OR APPROVED EQUALCOVER TO BE LETTERED"DRAIN" (3" HIGH LETTERS)3/4" CRUSHED STONECOMPACTED SUBGRADENON-WOVENGEOTEXTILE MIRAFI140N OR APPROVEDEQUAL (SEE SPECIFICATIONS)STEPS12" O.C.WATERTIGHT NON-SHRINKGROUT (TYP.)O-RING RUBBER GASKET JOINTPER ASTM C443 OR BUTYL RUBBERFLEXIBLE ROPE JOINT SEALANTPER ASTM C 990/AASHTO M-198B12" MIN.12" MIN. (TYP)SCALE: N.T.S.TYPICAL DRAIN TRENCH DETAILNOTES:1.MATERIALS AND METHODS OFINSTALLATION SHALL CONFORM TOTHE MUNICIPAL DPW AND/ORENGINEERING DEPARTMENTSTANDARDS AND SPECIFICATIONS.MAX TRENCH WIDTH=12"PIPE O.D. + 2 FT.(MIN. = 3 FT.)HALF SECTIONIN EARTHHALF SECTIONIN ROCK12"*MIN. INROCK8" MIN.IN EARTH DIA.VA R I E S PLACE SHEETINGWHERE INDICATEDOR DIRECTEDCOMPACTED COMMON FILLFREE OF STONES LARGERTHAN 3" DIA. 8" MAX. LIFTS.EXCAVATED FLOWABLE FILLOR INFRA RED TREATMENTWITHIN TOWN RIGHT-OF-WAY,AT THE TOWN'S DISCRETION.LIMITS FOR NORMALEXCAVATIONUNDISTURBED MATERIALCOMPACTED PROCESSEDGRAVEL, MASSDOT M1.03.1AGAINST UNDISTURBEDMATERIAL OR SHEETING(8" MAX. LIFTS)NO LEDGE OR UNEXCAVATEDMATERIAL SHALL PROJECTBEYOND THIS LINELIMITS FOR ROCKEXCAVATION℄ PIPE℄PIPE6" MIN. W SLOPESECTION A-APLAN VIEW6"FLARED END SECTION WITH RIP RAP APRONFLARED ENDSECTION. SEENOTE 1LAA6" - 3/4" CRUSHED STONE BASE PERMassDOT SPEC M2.01.4STONE FOR PIPE ENDS(M.2.02.3) PER MassDOTSTD. SPECIFICATIONSFOR HIGHWAY ANDBRIDGES.BOTTOM OFSLOPEAAALL FILTER FABRIC TO BE 6" MIN. BELOWFINISH GRADEGRADE WRAPS AROUNDFLARED ENDNOTES:1.THE FLARED END SECTION (FES) AND THE LAST RUN OF PIPEOUTLETTING TO THE FES SHALL BE REINFORCED CONCRETE (RCP)DIA. (IN.)LA (FT.)WA (FT.)12810151012181214241416301620TAPER APRON TO MATCH FLARED END TAPER DIA.VARIESMIRAFI FABRIC 140N NON-WOVEN, WRAPUNDER EDGESUNDISTURBED OR COMPACTEDSUBGRADESLOPE APPENDIX C Connecticut DEEP General Permit for the Discharge of Stormwater and Dewatering Wastewaters from Construction Activities Note: The 2022 CGP is available at https://portal.ct.gov/-/media/deep/permits_and_licenses/water_discharge_general_permits/stormconstgppdf.pdf APPENDIX D CTDOT MS4 Project Design Maximum Extent Practicable Worksheet CTDOT MS4 Project Design MEP Worksheet Instructions CT DOT MS4 Project Design MEP Worksheet Instructions Page 1 of 7 Version 3_ 2020-02-26 The CTDOT MS4 Project Design MEP Worksheet is intended to be a living document that follows a project throughout its design. The primary intent of the Worksheet is to track the required metrics that must be reported to CT DEEP annually in order to comply with the DOT MS4 General Permit. It also serves as the required documentation to demonstrate that stormwater mitigation was pursued in a project’s design to the maximum extent practical. Section 1: Project Information Indicate the Project, Number, Title and Location. Section 2: Existing Conditions Before the end of Preliminary Design, fill out the requested information available regarding a project site’s existing conditions. As missing or updated information (e.g., soil infiltration potential, depth to groundwater, depth to bedrock) becomes available during later design phases, edit the Existing Conditions accordingly. EC1. Total Project Area – Total Project Area consists of all areas needed to complete the project which generally consists of the limits of disturbance with an appropriate buffer and includes any lay down areas. The project area could also include abutting DOT owned land where there are no proposed construction activities and areas that will not be impacted by the project. Designer Insight - Total project area will be used in subsequent calculations for Directly Connected Impervious Area (DCIA) and determining the project’s Water Quality Volume. (See instructions for EC2 and DC1, below.) EC2. Pre-Construction Directly Connected Impervious Area (DCIA) for the Project - Determine the amount of pre-construction DCIA in acres and as a percentage of the overall project area. DCIA is surface area within the project limits that a) is impervious, and b) drains to a wetland or watercourse either directly or via a storm sewer system discharge. Impervious cover includes pavement, sidewalks, roofs, exposed ledge, gravel roads/parking (C > 0.7). The %-DCIA will typically remain consistent as the design progresses unless the total project area changes. Designer Insight - The primary purpose of %-DCIA is to determine the WQV retention design goal, which will be the minimum goal for impervious area disconnections (see instructions for DC1, below.) EC3. Soil Infiltration Potential – Select either Existing Report/Soils Map or Field Verified as the source of the soils information. Choose from Good/Fair, Poor or Mixed as the best overall description of the project’s surficial geology ability to infiltrate. Generally, soils with an infiltration rate of at least 0.3 in/hr are considered as Good/Fair. Retention BMPs will need to be designed to infiltrate all of the ponded water within 48 hours. Select Mixed if the soil conditions vary throughout a large project area. Designer Insight - The soil infiltration potential will be used to inform whether infiltration Best Management Practices (BMPs) are feasible. Any existing information (such as prior soils reports) for the project area should be reviewed. If no prior, area-specific soil information is available, utilize the Soil Drainage Class map from CTECO to identify preliminary locations. http://www.cteco.uconn.edu/map_catalog.asp?. Areas classified as Somewhat Poorly Drained, Poorly Drained or Very Poorly Drained Areas can be noted as “Poor” on the Worksheet and do not warrant further consideration for infiltration BMPs. All other areas should be considered as “Good/Fair” and, unless other factors prohibit infiltration, actual infiltration rates will require field verification. CT DOT MS4 Project Design MEP Worksheet Instructions Page 2 of 7 Ver 3 .2020-02-26 Section 2: Existing Conditions (continued) EC4. Depth to Groundwater – At the start of design, check the “TBD” box unless existing data from a previous project or other sources is available. As design progresses and as subsurface investigations are completed, indicate the depth to maximum groundwater as a range over the entire project area. Maximum groundwater is the level to which groundwater rises for a duration of one month or longer during the wettest season of the year. Report zero as the low end of the range if wetlands or standing water are present within the project limits. If depth to groundwater is deeper than the depth to bedrock, indicate as “BR” (below rock). If seasonal variations in depth to groundwater are known, defer to the seasonal high for this Worksheet. EC5. Depth to Bedrock – At the start of design, check TBD unless existing data from a previous project or other sources is available. As design progresses and as subsurface investigations are completed, indicate the depth to bedrock as a range over the entire project area. Report zero as the low end of the range if bedrock outcrops are present within the project limits. Designer Insight - The purpose of the depth to groundwater and depth to bedrock is to inform and document whether shallow groundwater or shallow bedrock will make it unfeasible to include infiltration/retention BMPs (see page 2 of DOT MS4 Worksheet) as part of the design. EC6. Aquifer Protection Area - Indicate (Y/N) if any part of the project falls within an aquifer protection area. This information will be reported to the design unit on the PNDF provided by Office of Environmental Planning. Designer Insight – If the project is located within an Aquifer Protection Area, then this is a limiting condition to be documented with respect to the infiltration/retention BMPs listed on page 2. Infiltration/retention BMPs should not be pursued in these areas in order to protect groundwater quality from potential contaminants associated with transportation-related spills or other releases. EC7. MS4 Priority Area - Indicate (Y/N) if any part of the project falls within an “MS4 Priority Area.” If yes, indicate which of the three types of priorities (check all that apply). If “Impaired Waterbody” is checked, pick the impairment(s) from the list of drop down boxes. This information will be reported to the design unit on the PNDF provided by OEP. Designer Insight – Identifying the project’s location relative to MS4 Priority Areas is a requirement of the MS4 permit. If a receiving water is impaired, identifying the specific impairment will help inform the suitability of certain BMPs. Refer to the CTDOT BMP Matrix. EC8. Contamination known or suspected to be present? Indicate (Y/N) whether soil and/or groundwater contamination is known or suspected to be present. Check “Yes” if the Task 100 Environmental Hazardous Screening Form provided by DOT Environmental Compliance recommended that a Task 210 Subsurface Investigation be performed. Designer Insight – If contaminated soil and/or groundwater is known or suspected to be present, then careful consideration must be made before deciding whether infiltration/retention BMPs are feasible. If the surrounding land use is intensely developed and public drinking water is readily available, or if existing groundwater quality is known to be unsuitable for drinking water supply without treatment, or if remediation is planned as part of the project (for reasons other than BMP implementation), then an infiltration/retention BMP may still be appropriate. CT DOT MS4 Project Design MEP Worksheet Instructions Page 3 of 7 Ver 3 .2020-02-26 Section 2: Existing Conditions (continued) EC9. Adjoining DOT ROW beyond project limits available for stormwater quality management. Indicate the approximate acreage of potentially suitable DOT property that is laterally beyond the project limit. This can include:  Additional property in the DOT ROW that was not included in the Total Project Area;  Adjacent parcels presently owned by DOT;  Excess property from a parcel to be acquired for the project for reasons other than MS4. Include only the amount of undeveloped area beyond the project limits. Attach a sketch depicting these areas. Designer Insight – The available DOT-owned area surrounding a project is a general metric to help inform the possibility of locating stormwater BMPs near the project site if the area directly within the project limits is not sufficient. It is understood that the lateral distance from the project limit to the ROW limit can vary significantly, especially for linear projects that extend over a long distance. Include other relevant information related to additional area in the Notes box at the bottom of the page. Section 3: Designed Conditions This portion of the Worksheet was established based on a typical 30/60/90/FDP design process. At each phase, the progression of key metrics associated with a stormwater quality design are tracked by the Worksheet. It is understood that not every project will follow this exact design process. Any information that has not changed compared to what was recorded during the previous design phase review can be indicated as such (e.g., “no change” or “same”) However, the FDP column must contain the final values. Section 3 will rely heavily on the information recorded on Section 4: Stormwater BMP Selection Summary. As such, Section 4 will also need to be completed and updated with each corresponding milestone design review. Refer to the instructions below on how to complete Section 4. At Design Approval, complete Section 3’s 30%-Design Phase column based on the best available information. If a project is using intermediate design reviews, complete the 60%-Design Phase column and/or the 90%-Design Phase column during the respective milestone reviews. These are working-versions of the Worksheet. Save the working versions of the Worksheet to the project’s appropriate 310_Milestone_ Submissions folder in ProjectWise. Designer Insight – Data from a project’s drainage report should be used when available. Review the Worksheet to ensure the reported metrics are consistent with the drainage report. At the Final Design Plan milestone, complete the FDP Phase column. Upon completion of this column, this will be the record version of the project’s Worksheet. Save the Worksheet to the project’s ProjectWise 310_Milestone_ Submissions/100% folder. DC1. Water Quality Volume (WQV) retention design goal (acre-feet) – Determine the WQV retention design goal by first calculating the Water Quality Volume (WQV) for the project. The WQV is the volume of runoff generated across a site by one inch (1”) of rainfall. The proposed impervious area (C > 0.7) must be known to determine the WQV. WQV = (1-inch)(R)(A)/12 WQV = water quality volume (ac-ft) R = volumetric runoff coefficient = 0.05+0.009(I) I = percent impervious cover for post-construction condition as designed (C > 0.7). A = Total DOT-Owned Project Area in acres. Designer Insight - The percent impervious cover (I) in the calculation above is the total impervious area, not just that which is directly connected. This is different from the DCIA area computed for the existing condition (EC2), which excludes surfaces that do not drain to a wetland or watercourse directly or via a storm sewer discharge. CT DOT MS4 Project Design MEP Worksheet Instructions Page 4 of 7 Ver 3 .2020-02-26 Section 3: Designed Conditions (continued) The equation above calculates a retention volume based on 1” of rainfall. It is not necessarily the WQV goal for the project. The project’s WQV retention design goal is determined based on the percentage of DCIA at the pre-construction stage (EC2). If the pre- construction DCIA is greater or equal to 40% of the project area, then project’s retention goal will be ½ x Water Quality Volume (WQV). If the preconstruction DCIA is less than 40%, then the retention goal will be 1.0xWQV, or simply the WQV. For many redevelopment projects, the pre-construction DCIA percentage will be above 40% and the retention design goal will be equal to ½ the WQV. Designer insight – Designers should note that the Construction Stormwater General Permit bases the WQV goal on the project’s percentage of total impervious area. The DOT’s MS4 Permit uses the percentage of directly connected impervious area to determine the WQV goal. This difference means some projects will require retention/treatment of ½ the WQV for the Construction Permit but the full WQV for compliance with the MS4 Permit. If possible, an estimate of the retention goal should be calculated during preliminary design in order to approximate the extent of best management practices that will be needed. If the extent of impervious cover is not fully known by Design Approval, then the WQV cannot be calculated and the TBD box should be checked. Provide the information during a later design phase. An accurate value must always be provided for the FDP milestone. DC2. WQV Goal Retained – Copy the total WQV Retained value column in Section 4: Stormwater BMP Selection Summary. Refer to Section 4 of these instructions. DC3. WQV Goal Treated – Copy the total WQV Treated value column in Section 4: Stormwater BMP Selection Summary. Refer to Section 4 of these instructions. Designer insight – Incorporate run-off retention BMPs to the maximum extent practical as site conditions allow, documenting site constraints on page 2 that are consistent with the Existing Condition information provided on page 1. If the amount of run-off retained in the design condition fails to meet the WQV retention design goal (DC1), determine the shortfall and evaluate the use of treatment BMPs to make up the difference. Treatment without infiltration should only be incorporated into the design when runoff retention can be demonstrated to be unfeasible. Designer insight - It is acceptable to take credit for disconnecting off site DCIA areas that drain to on-site BMPs. DC4. Total WQV Retained or Treated – Add the WQV Retained per 1” of Rainfall (DC2) to the WQV Treated (DC3) and indicate the total. Designer insight – The Total WQV Retained or Treated is compared to the WQV retention design goal (DC1) to determine if the project has met the intended run-off reduction target. If DC4 is less than DC1, review any adjoining DOT ROW beyond the project limits (identified in EC9) where retention BMPs (primarily) or treatment BMPs (secondarily) could be constructed in order to meet the full WQV retention design goal (DC1). Incorporate the retention/treatment of the alternative site(s) and update page 2. If DC4 is still less than DC 1 after evaluating alternative sites and incorporating BMPs outside the project limits, then describe any limiting factors that make alternative locations unfeasible for BMPs in the Notes box on the bottom of page 1. Review the limiting site constraints in Section 4 with Section 1: Existing Conditions for accuracy and consistency. Designer insight – For projects that do not meet the required WQV retention design goal, the MS4 Program will be evaluating future water quality improvement projects within the same local drainage basins or in other priority areas to mitigate the shortfall from the original project. CT DOT MS4 Project Design MEP Worksheet Instructions Page 5 of 7 Ver 3 .2020-02-26 Section 3: Designed Conditions (continued) DC5. Post-construction DCIA (acres) – Determine the amount of post-construction DCIA. Here, DCIA is surface area within the project limits that a) is impervious and b) drains to a wetland or watercourse either directly or via a storm sewer system discharge. Impervious cover includes pavement, sidewalks, roofs (Facilities projects), exposed ledge, gravel roads/parking (C > 0.7). Do not include turf, temporary pavement areas or temporary access roads. If the post-construction DCIA is unknown during the Preliminary Design phase, check TBD and provide the information at a later design phase. Designer insight – For the Post-Construction DCIA value, do not count impervious areas that will drain to BMPs designed to retain and/or treat enough runoff for the area to have met the WQV retention design goal. Areas not directed to a qualifying BMP must be counted as DCIA. The goal is to reduce the amount of DCIA (see DC7 , below.) DC6. Pre-construction DCIA (acres) – Copy the Pre- Construction DOT-Owned Directly Connected Impervious Area (DCIA) from line EC2. DC7. Change in DCIA from pre- to post-construction (acres) - Subtract the Pre-construction DCIA (DC6) from the Post-construction directly connected impervious area (DC5). A negative value indicates that the amount of DCIA will decrease. A positive value indicates that the project will cause DCIA to increase. Review the limiting site constraints in Section 4 with the recorded existing conditions in Section 1 for accuracy and consistency. Designer insight – The DOT MS4 General Permit has a statewide compliance metric to reduce DOT DCIA by 2% within five years compared to a July 2019 baseline. While a project will not be in violation if the maximum extent practical falls short of the permit requirements for DCIA and runoff reductions, any additional DCIA added by projects will make meeting the 2%-reduction that much harder. Designer insight – Since BMPs may have drainage areas that extend beyond the chosen project area, it is acceptable to take credit for disconnecting off site DCIA areas that drain to on-site BMPs and compensate for DCIA remaining on-site. In rare cases it will be possible to disconnect more DCIA than exists within the project area. Section 4: Stormwater BMP Selection Summary This section of the Worksheet is intended to present the designer with several specific BMP types that are expected to be the most feasible for transportation- related projects. Refer to the CTDEEP’s 2004 Connecticut Stormwater Quality Manual for other acceptable BMPs and their respective design criteria. Innovative BMPs not listed in the Connecticut Stormwater Quality Manual are also encouraged so long as good engineering judgement is used when assigning retention and treatment capacities. Designer insight – Designers can refer to the BMP one pagers and the examples that have been prepared on various BMPs for guidance on their design. The examples include Natural Dispersion, Grass Channel , Check Dam (Supplemental), Infiltration Trench and Infiltration Basin. The key metrics associated with a stormwater quality design are tracked by the Worksheet as the project’s design progresses. Complete the Stormwater BMP Selection Summary at each milestone design review. Indicate the current design review phase by checking off the appropriate box in the upper left corner. Designer insight – While Section 3 (Design Conditions) and Section 4 (Stormwater BMP Selection Summary) were established based on a typical 30/60/90/FDP design process, it is understood that not every project will follow this exact design process and that a project’s metrics may not change from one phase to the next. At the project’s Design Approval, potential opportunities to improve water quality with stormwater BMPs should be identified with preliminary locations shown on project plans. Design phases after Design Approval will need to verify any preliminary assumptions used in siting and sizing BMPs. Examine all limiting factors for each BMP (see Site Constraints for each type of stormwater management measure listed on the designer worksheet). CT DOT MS4 Project Design MEP Worksheet Instructions Page 6 of 7 Ver 3 .2020-02-26 Section 4: Stormwater BMP Selection Summary (continued)  Permeability/percolation information  Depth to maximum groundwater  Depth to bedrock Update Section 1 as needed based on the field investigations. Designer insight – A best management practice that does not meet every design requirement listed in the Stormwater Quality Manual will still provide a benefit, albeit not the full possible extent. Document the assumptions used in determining the proportional amount of runoff retainage and/or treatment that the BMP will provide given its site constraints. The BMPs listed under the Stormwater BMP Selection Summary are grouped into four categories: 1. Disconnection BMPs promote flow dispersion and reduce flow velocities in order to allow the downstream terrain to absorb and/or filter the runoff. Consider the following factors of the downstream terrain when determining its capacity to retain or treat: slope, soil type, and distance to the nearest surface water or wetland. Consider augmenting the downstream terrain to retain or treat a greater volume of runoff. For example, soil amendments can be used to increase infiltration capacity or certain seed mixes could be specified to promote beneficial vegetation. 2. Conveyance & Disconnection BMPs remove pollutants from the runoff as it is collected and conveyed away from the transportation infrastructure. The slope, soil type, and length of the conveyance will generally dictate its capacity to retain and/or treat. Also consider the downstream terrain, if any, between the conveyance’s outfall and the nearest surface water or wetland. Designer insight – For a Disconnection BMPs and Conveyance & Disconnection BMPs to meet the WQV retention design goal, they may need to be coupled with one or more other BMPs designed per the criteria in the CT DEEP Stormwater Quality Manual. 3. Infiltration/Retention BMPs are practices that retain the WQV or a portion of the WQV, temporarily holding it before it infiltrates into the native soil. Any BMP that does not allow the WQV from entering a storm system or adjacent surface water body would qualify for infiltration/retention credit. 4. Treatment BMPs are practices that improve the water quality but do not reduce or retain the volume. WQV Retained – In this column, list the amount of the WQV retained by each BMP used in the design. For example, if a project uses three separate infiltration trenches then each trench should be individually listed (under in the infiltration/retention section) and the WQV retained by each recorded in the cell where the “infiltration trench” row and the “WQV Retained” column intersect. WQV Treated – In this column, list the amount of the WQV treated by each BMP used in the design. For example, if a project has incorporated two separate wet detention basins then each basin should be individually listed (under the “treatment” section) and the volume treated by each basin should be recorded in the cell where the “wet basin” row and the “WQV Treated” column intersect. Designer insight – The amount of water that a Disconnection BMP or a Conveyance & Disconnection BMP can infiltrate might be limited to only a portion of the WQV retention design goal. In additional to infiltration, consider the amount of treatment the BMP provides to the portion of the WQV that cannot be retained. Include the amount of treatment under the WQV Treated column. CT DOT MS4 Project Design MEP Worksheet Instructions Page 7 of 7 Ver 3 .2020-02-26 Section 4: Stormwater BMP Selection Summary (continued) DCIA Captured (acres) – In this column, list the amount of directly connected impervious area (DCIA) that is captured by the BMP being proposed. DCIA Captured is the amount of surface area within the project limits that a) is impervious and b) drains to a BMP for retention and/or treatment that would otherwise of drained to a wetland or watercourse either directly or via a storm sewer system discharge. DCIA Disconnection Credit (Percentage) – In this column, record the DCIA Disconnection Credit for the proposed BMP. DCIA Disconnection Credit is the percentage of DCIA directed to a BMP that can be considered disconnected. To find the DCIA Disconnection Credit percentage for different BMPs refer to the BMP one pagers which can be found on the CTDOT MS4 Webpage. (https://portal.ct.gov/DOT/PP_Envir/Water_Natural_Re sources/CTDOT-MS4) DCIA Disconnection Credit (Acres) – DCIA Disconnection Credit is the area directed to a BMP that can be considered disconnected. To find this number multiply the total amount of DCIA Captured (acres) by the DCIA Disconnection Credit percentage of the BMP. Site Constraints: For each of the four categories of BMPs, select one or more site constraint from the drop down boxes. Site constraints are characteristics of the project location that prevent the selection of the corresponding type of BMP in the project’s design. Selected site constraints must be consistent with the information provided in Section 2. Designer insight – If a BMP is included into a project, and if the WQV design retention goal is met (see Section 3), then a Site Constraint does not need to be selected for that BMP’s category. Every project that affects drainage shall at least have completed the Worksheet with its FDP. The FDP-version will be considered the final version of the worksheet. All metrics extracted for the annual DEEP reports will come from the final FDP Worksheet. Save the FDP version of the Worksheet to the project’s ProjectWise 310_Milestone_ Submissions/100% folder. Worksheet users should refer to the CT DOT MS4 Project Design MEP Worksheet Instructions CTDOT MS4 Design MEP Worksheet Version 3 Revised 2/26/2020 Page 1 of 2 CTDOT MS4 Project Design Maximum Extent Practicable (MEP) Worksheet Section 1: Project Information Project #: Title: Location: Section 2: Existing Conditions EC1 Total Project Area acres EC2 Pre-construction Directly Connected Impervious Area (DCIA): acres EC3 Soil Infiltration Potential Data Source: ☐Existing Report / Soils Map ☐Field Verified ☐Good/Fair ☐Poor ☐Mixed EC4 Depth to Maximum Groundwater ☐TBD to ft below grade EC5 Depth to Bedrock ☐TBD to ft below grade EC6 Aquifer Protection Area? (from PNDF) ☐Yes ☐No EC7 MS4 Priority Area? (from PNDF) ☐Yes (See Below) ☐No Check All That Apply ☐Urbanized Area ☐DCIA >11% ☐Impaired Waterbody (See Below) Select All Impairments That Apply EC8 Contamination known or suspected to be present? (From Environmental Compliance) ☐Yes ☐No EC9 Adjoining DOT ROW beyond project limits available for stormwater quality management acres Section 3: Designed Conditions Water Quality Calculations 30% Design 60% Design 90% Design FDP DC1 WQV retention design goal ac-ft ☐ TBD ac-ft ac-ft ac-ft DC2 WQV goal retained (refer to page 2) ac-ft ac-ft ac-ft ac-ft DC3 WQV goal treated (refer to page 2) ac-ft ac-ft ac-ft ac-ft DC Total WQV retained and treated ac-ft ac-ft ac-ft ac-ft DC5 Post-construction DCIA(acres) ac. ☐ TBD ac. ac. ac. DC6 Pre-construction DCIA (refer to EC2 above) ac. ac. ac. ac. DC7 Change in DCIA from pre- to post-construction Can be positive (DCIA gained) or negative (DCIA lost) ac. ☐ TBD ac. ac. ac. Date completed Completed by (initials) Reviewed by (initials) Notes: % 4 Full 1/2"-WQV Worksheet users should refer to the CT DOT MS4 Project Design MEP Worksheet Instructions. Refer to the 2004 CT Stormwater Quality Manual for more information on BMP criteria and limitations. CTDOT MS4 Design MEP Worksheet Version 3 Revised 2/26/2020 CTDOT MS4 Design MEP Worksheet Version 3 Revised 2/26/2020 Page 2 of 2 Section 4: Stormwater BMP Selection Summary Design Phase ☐30% ☐60% ☐90% ☐FDP WQV Retained (ac-ft) WQV Treated (ac-ft) DCIA Captured (Acres) DCIA Disconnection Credit (%) DCIA Disconnection Credit (acres) Site Constraints Disconnection (Dispersion) Conveyance (Swales / Channels) Infiltration / Retention Treatment TOTAL Notes: APPENDIX E Construction Site Environmental Inspection Report (CSEIR) State of Connecticut Department of Transportation Construction Site Environmental Inspection Report TThhiiss FFoorrmm MMuusstt BBee CCoommpplleetteedd AAtt LLeeaasstt OOnnccee AA WWeeeekk AAnndd WWiitthhiinn TTwweennttyy FFoouurr ((2244)) HHoouurrss OOff TThhee EEnndd OOff AA SSttoorrmm EEvveenntt TThhaatt IIss 00..11 iinncchheess OOrr GGrreeaatteerr General Information Project Number Date Permit Number(s) Location Phone No. Project Engineer Chief Inspector Contractor Describe present phase of construction/activities that are occurring Type of Inspection: Weekly Pre-storm event During storm event Post-storm event Weather Information Has there been a storm event since the last inspection? Yes No If yes, provide: Storm Start Date & Time: Storm Duration (hrs): Type and Approximate Amount of Precipitation (in): Weather at time of this inspection? Clear Cloudy Rain Sleet Fog Snowing High Winds Temperature: Site-specific BMPs  Number the structural and non-structural BMPs on your site map and list them below (add as many BMPs as necessary). Carry a copy of the numbered site map for reference with you during your inspections. BMP Maintenance BMP or Observation Site and Location BMPs Installed ? BMP Maintenance Required? Remedial Action Required and Date Contractor was Notified *ALL REMEDIAL ACTIONS MUST BE COMPLETED WITHIN 24 HOURS* Date Fixed Photo Taken ? Repeat Failure? 1 Yes No Yes No Yes No Yes No 2 Yes No Yes No Yes No Yes No 3 Yes No Yes No Yes No Yes No Environmental Inspector: Signature: Date: Reviewed by: Signature: Date: Are there any sediment discharges to a regulated area occurring or have any occurred since the last inspection? Yes No IIff yyeess,, ccoonnttaacctt tthhee DDiissttrriicctt EEnnvviirroonnmmeennttaall CCoooorrddiinnaattoorr iimmmmeeddiiaatteellyy.. Describe the discharge including location, time identified, and the approximate amount of sediment. (on back) APPENDIX F Notice of Termination Form Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 1 of 7 Rev. 01/05/2022 General Permit for the Discharge of Stormwater and Dewatering Wastewaters from Construction Activities Notice of Termination Form: Non-Solar Projects This Notice serves as a request to terminate the below listed permit as well as any applicable Letter(s) of Credit. Part I: Permittee Information The below information is required in accordance with Section 6(b) of the General Permit. 1. Permit Number: GSN 2. Registrant: 3. Site Address: City/Town: State: Zip Code: 4. Date of completion of construction: Date all storm drainage structures were cleared of construction sediment and debris: Beginning and Ending Dates of post-construction inspections: Date of final stabilization inspection(s)*: Qualified Inspector who conducted the Final Stabilization Inspection: (This person must sign Part III) 5. Check the post-construction activity(ies)** at the site (check all that apply): ☐Industrial ☐ Residential ☐ Capped Landfill ☐ Commercial ☐ Solar Array ☐ Other: * The Final Stabilization Inspection must occur at least one full growing season after final stabilization has been achieved. A full growing season is defined as the timeframe encompassed by two consecutive full seeding seasons: April 1 through June 15, and August 15 through October 1. If final stabilization is achieved during a seeding season, the following seeding season will be considered the first full seeding season after final stabilization has been achieved. ** If the post-construction activity involves solar arrays, the Department may require that the “Solar Projects: Notice of Termination Form” be used. Any questions regarding the necessity of such a form for the project can be sent via email to DEEP.StormwaterStaff@ct.gov. Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 2 of 7 Rev. 01/05/2022 Locally Approvable Projects Must Complete the following Part II - (Attach additional sheets as needed) Part II: Locally Approvable Post-Construction Inspection Certification The below information is required in accordance with Section 5(b)(4)(C)(i) of the General Permit. Certification by a Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional / District Representative “I hereby certify that I am a qualified professional engineer / a qualified soil erosion and sediment control professional / a representative of the District in which the site is located as defined in Section 2 of the General Permit for Discharge of Stormwater and Dewatering Wastewaters from Construction Activities (general permit). I am familiar with the site described in this Notice of Termination and the requirements of the general permit. I certify, based on my personal inspection of the site pursuant to Section 6(a) of the general permit that all post- construction measures have been installed as specified in the permittee’s Stormwater Pollution Control Plan and in accordance with Section 5(b)(2)(C) of the general permit and that all such measures have been cleaned of construction sediment and debris. I understand that this certification is part of a registration submitted in accordance with section 22a-430b of Connecticut General Statutes and is subject to the requirements and responsibilities for a qualified professional in such statute. I also understand that knowingly making any false statement in this certification may be punishable as a criminal offense, including the possibility of fine and imprisonment, under section 53a-157b of the Connecticut General Statutes and any other applicable law.” Signature of Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional / Representative of the District Date Printed Name of Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional / Representative of the District Title Check off the qualifications of the signatory of the above part: ☐ Qualified Professional Engineer ☐ Qualified Soil Erosion and Sediment Control Professional ☐ Representative of the District Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 3 of 7 Rev. 01/05/2022 Locally Exempt Projects Must Complete the following Part II - (Attach additional sheets as needed) Part II: Locally Exempt Post-Construction Inspection Certification The below information is required in accordance with Section 5(b)(4)(C)(ii) of the General Permit. Certification by a Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional “I hereby certify that I am a qualified professional engineer / a qualified soil erosion and sediment control professional as defined in Section 2 of the General Permit for Discharge of Stormwater and Dewatering Wastewaters from Construction Activities (general permit). I am familiar with the site described in this Notice of Termination and the requirements of the general permit. I certify, based on my personal inspection of the site pursuant to Section 6(a) of the general permit that all post-construction measures have been installed as specified in the permittee’s Stormwater Pollution Control Plan and in accordance with Section 5(b)(2)(C) of the general permit and that all such measures have been cleaned of construction sediment and debris. I understand that this certification is part of a registration submitted in accordance with section 22a-430b of Connecticut General Statutes and is subject to the requirements and responsibilities for a qualified professional in such statute. I also understand that knowingly making any false statement in this certification may be punishable as a criminal offense, including the possibility of fine and imprisonment, under section 53a-157b of the Connecticut General Statutes and any other applicable law.” Signature of Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional Date Printed Name of Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional Title Check off the qualifications of the signatory of the above part: ☐ Qualified Professional Engineer ☐ Qualified Soil Erosion and Sediment Control Professional Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 4 of 7 Rev. 01/05/2022 State Agency Projects Must Complete the following Part II - (Attach additional sheets as needed) Part II: State Agency Post-Construction Inspection Certification The below information is required in accordance with Section 5(b)(4)(C)(iii) of the General Permit. Certification by a DOT District Engineer or his/her designee / a DOT District Environmental Coordinator / a designated employee of another state agency “I hereby certify that I am a DOT District Engineer or his/her designee / a DOT District Environmental Coordinator / a designated employee of another state agency as defined in Section 2 of the General Permit for Discharge of Stormwater and Dewatering Wastewaters from Construction Activities (general permit). I am familiar with the site described in this Notice of Termination and the requirements of the general permit. I certify, based on my personal inspection of the site pursuant to Section 6(a) of the general permit that all post-construction measures have been installed as specified in the permittee’s Stormwater Pollution Control Plan and in accordance with Section 5(b)(2)(C) of the general permit and that all such measures have been cleaned of construction sediment and debris. I understand that this certification is part of a registration submitted in accordance with section 22a-430b of Connecticut General Statutes and is subject to the requirements and responsibilities for a qualified professional in such statute. I also understand that knowingly making any false statement in this certification may be punishable as a criminal offense, including the possibility of fine and imprisonment, under section 53a-157b of the Connecticut General Statutes and any other applicable law.” Signature Date Printed Name Title Check off the qualifications of the signatory of the above part: ☐ Qualified Professional Engineer ☐ Qualified Soil Erosion and Sediment Control Professional ☐ Representative of the District Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 5 of 7 Rev. 01/05/2022 All Projects Must Complete the following Part III - (Attach additional sheets as needed) Part III: Final Stabilization Inspection Certification The below information is required in accordance with Section 5(b)(4)(D) of the General Permit. Certification by a Qualified Inspector “I hereby certify that I am a qualified inspector as defined in Section 2 of the General Permit for Discharge of Stormwater and Dewatering Wastewaters from Construction Activities (general permit). I am familiar with the site described in this Notice of Termination and the requirements of the general permit. I certify, based on my personal inspection of the site pursuant to Section 6(a) of the general permit that the site has been stabilized, as defined in Section 2 of the general permit, for a period of no less than one full growing season following the cessation of construction activities. I further certify that there is no active erosion or sedimentation present on site and no disturbed areas remain exposed. I also understand that knowingly making any false statement in this certification may be punishable as a criminal offense, including the possibility of fine and imprisonment, under section 53a-157b of the Connecticut General Statutes and any other applicable law.” Signature of Qualified Inspector Date Printed Name of Qualified Inspector Title Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 6 of 7 Rev. 01/05/2022 All Projects Must Complete the following Part IV - (Attach additional sheets as needed) Part IV: Permittee Certification The below information is required in accordance with Section 5(b)(4)(D) of the General Permit. Certification by the Permittee “I have personally examined and am familiar with the information submitted in this document and all attachments thereto, and I certify that, based on reasonable investigation, including my inquiry of those individuals responsible for obtaining the information, the submitted information is true, accurate and complete to the best of my knowledge and belief. I understand that a false statement made in this document or its attachments may be punishable as a criminal offense, in accordance with section 22a-6 of the Connecticut General Statutes, pursuant to section 53a-157b of the Connecticut General Statutes, and in accordance with any other applicable statute.” Signature of Permittee Date Printed Name of Permittee Title Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 7 of 7 Rev. 01/05/2022 All Projects Must Complete the following Part V - (Attach additional documentation as needed) Part V: Additional Submittals The following attachments are required to be submitted along with the Notice of Termination Form: ☐ Post-Construction Inspection Report (must contain photos with time stamps) ☐ Final Stabilization Inspection Report (must contain photos with time stamps) Complete and submit this form in accordance with the general permit (DEEP-WPED-GP-015) to ensure the proper handling of the termination. Print or type unless otherwise noted. Submit this Notice of Termination Form to the address below, as well as via email to DEEP.StormwaterStaff@ct.gov: WATER PERMITTING AND ENFORCEMENT DIVISION/STORMWATER GROUP DEPARTMENT OF ENERGY & ENVIRONMENTAL PROTECTION 79 ELM STREET HARTFORD, CT 06106-5127 APPENDIX D CTDOT MS4 Project Design Maximum Extent Practicable Worksheet CTDOT MS4 Project Design MEP Worksheet Instructions CT DOT MS4 Project Design MEP Worksheet Instructions Page 1 of 7 Version 3_ 2020-02-26 The CTDOT MS4 Project Design MEP Worksheet is intended to be a living document that follows a project throughout its design. The primary intent of the Worksheet is to track the required metrics that must be reported to CT DEEP annually in order to comply with the DOT MS4 General Permit. It also serves as the required documentation to demonstrate that stormwater mitigation was pursued in a project’s design to the maximum extent practical. Section 1: Project Information Indicate the Project, Number, Title and Location. Section 2: Existing Conditions Before the end of Preliminary Design, fill out the requested information available regarding a project site’s existing conditions. As missing or updated information (e.g., soil infiltration potential, depth to groundwater, depth to bedrock) becomes available during later design phases, edit the Existing Conditions accordingly. EC1. Total Project Area – Total Project Area consists of all areas needed to complete the project which generally consists of the limits of disturbance with an appropriate buffer and includes any lay down areas. The project area could also include abutting DOT owned land where there are no proposed construction activities and areas that will not be impacted by the project. Designer Insight - Total project area will be used in subsequent calculations for Directly Connected Impervious Area (DCIA) and determining the project’s Water Quality Volume. (See instructions for EC2 and DC1, below.) EC2. Pre-Construction Directly Connected Impervious Area (DCIA) for the Project - Determine the amount of pre-construction DCIA in acres and as a percentage of the overall project area. DCIA is surface area within the project limits that a) is impervious, and b) drains to a wetland or watercourse either directly or via a storm sewer system discharge. Impervious cover includes pavement, sidewalks, roofs, exposed ledge, gravel roads/parking (C > 0.7). The %-DCIA will typically remain consistent as the design progresses unless the total project area changes. Designer Insight - The primary purpose of %-DCIA is to determine the WQV retention design goal, which will be the minimum goal for impervious area disconnections (see instructions for DC1, below.) EC3. Soil Infiltration Potential – Select either Existing Report/Soils Map or Field Verified as the source of the soils information. Choose from Good/Fair, Poor or Mixed as the best overall description of the project’s surficial geology ability to infiltrate. Generally, soils with an infiltration rate of at least 0.3 in/hr are considered as Good/Fair. Retention BMPs will need to be designed to infiltrate all of the ponded water within 48 hours. Select Mixed if the soil conditions vary throughout a large project area. Designer Insight - The soil infiltration potential will be used to inform whether infiltration Best Management Practices (BMPs) are feasible. Any existing information (such as prior soils reports) for the project area should be reviewed. If no prior, area-specific soil information is available, utilize the Soil Drainage Class map from CTECO to identify preliminary locations. http://www.cteco.uconn.edu/map_catalog.asp?. Areas classified as Somewhat Poorly Drained, Poorly Drained or Very Poorly Drained Areas can be noted as “Poor” on the Worksheet and do not warrant further consideration for infiltration BMPs. All other areas should be considered as “Good/Fair” and, unless other factors prohibit infiltration, actual infiltration rates will require field verification. CT DOT MS4 Project Design MEP Worksheet Instructions Page 2 of 7 Ver 3 .2020-02-26 Section 2: Existing Conditions (continued) EC4. Depth to Groundwater – At the start of design, check the “TBD” box unless existing data from a previous project or other sources is available. As design progresses and as subsurface investigations are completed, indicate the depth to maximum groundwater as a range over the entire project area. Maximum groundwater is the level to which groundwater rises for a duration of one month or longer during the wettest season of the year. Report zero as the low end of the range if wetlands or standing water are present within the project limits. If depth to groundwater is deeper than the depth to bedrock, indicate as “BR” (below rock). If seasonal variations in depth to groundwater are known, defer to the seasonal high for this Worksheet. EC5. Depth to Bedrock – At the start of design, check TBD unless existing data from a previous project or other sources is available. As design progresses and as subsurface investigations are completed, indicate the depth to bedrock as a range over the entire project area. Report zero as the low end of the range if bedrock outcrops are present within the project limits. Designer Insight - The purpose of the depth to groundwater and depth to bedrock is to inform and document whether shallow groundwater or shallow bedrock will make it unfeasible to include infiltration/retention BMPs (see page 2 of DOT MS4 Worksheet) as part of the design. EC6. Aquifer Protection Area - Indicate (Y/N) if any part of the project falls within an aquifer protection area. This information will be reported to the design unit on the PNDF provided by Office of Environmental Planning. Designer Insight – If the project is located within an Aquifer Protection Area, then this is a limiting condition to be documented with respect to the infiltration/retention BMPs listed on page 2. Infiltration/retention BMPs should not be pursued in these areas in order to protect groundwater quality from potential contaminants associated with transportation-related spills or other releases. EC7. MS4 Priority Area - Indicate (Y/N) if any part of the project falls within an “MS4 Priority Area.” If yes, indicate which of the three types of priorities (check all that apply). If “Impaired Waterbody” is checked, pick the impairment(s) from the list of drop down boxes. This information will be reported to the design unit on the PNDF provided by OEP. Designer Insight – Identifying the project’s location relative to MS4 Priority Areas is a requirement of the MS4 permit. If a receiving water is impaired, identifying the specific impairment will help inform the suitability of certain BMPs. Refer to the CTDOT BMP Matrix. EC8. Contamination known or suspected to be present? Indicate (Y/N) whether soil and/or groundwater contamination is known or suspected to be present. Check “Yes” if the Task 100 Environmental Hazardous Screening Form provided by DOT Environmental Compliance recommended that a Task 210 Subsurface Investigation be performed. Designer Insight – If contaminated soil and/or groundwater is known or suspected to be present, then careful consideration must be made before deciding whether infiltration/retention BMPs are feasible. If the surrounding land use is intensely developed and public drinking water is readily available, or if existing groundwater quality is known to be unsuitable for drinking water supply without treatment, or if remediation is planned as part of the project (for reasons other than BMP implementation), then an infiltration/retention BMP may still be appropriate. CT DOT MS4 Project Design MEP Worksheet Instructions Page 3 of 7 Ver 3 .2020-02-26 Section 2: Existing Conditions (continued) EC9. Adjoining DOT ROW beyond project limits available for stormwater quality management. Indicate the approximate acreage of potentially suitable DOT property that is laterally beyond the project limit. This can include:  Additional property in the DOT ROW that was not included in the Total Project Area;  Adjacent parcels presently owned by DOT;  Excess property from a parcel to be acquired for the project for reasons other than MS4. Include only the amount of undeveloped area beyond the project limits. Attach a sketch depicting these areas. Designer Insight – The available DOT-owned area surrounding a project is a general metric to help inform the possibility of locating stormwater BMPs near the project site if the area directly within the project limits is not sufficient. It is understood that the lateral distance from the project limit to the ROW limit can vary significantly, especially for linear projects that extend over a long distance. Include other relevant information related to additional area in the Notes box at the bottom of the page. Section 3: Designed Conditions This portion of the Worksheet was established based on a typical 30/60/90/FDP design process. At each phase, the progression of key metrics associated with a stormwater quality design are tracked by the Worksheet. It is understood that not every project will follow this exact design process. Any information that has not changed compared to what was recorded during the previous design phase review can be indicated as such (e.g., “no change” or “same”) However, the FDP column must contain the final values. Section 3 will rely heavily on the information recorded on Section 4: Stormwater BMP Selection Summary. As such, Section 4 will also need to be completed and updated with each corresponding milestone design review. Refer to the instructions below on how to complete Section 4. At Design Approval, complete Section 3’s 30%-Design Phase column based on the best available information. If a project is using intermediate design reviews, complete the 60%-Design Phase column and/or the 90%-Design Phase column during the respective milestone reviews. These are working-versions of the Worksheet. Save the working versions of the Worksheet to the project’s appropriate 310_Milestone_ Submissions folder in ProjectWise. Designer Insight – Data from a project’s drainage report should be used when available. Review the Worksheet to ensure the reported metrics are consistent with the drainage report. At the Final Design Plan milestone, complete the FDP Phase column. Upon completion of this column, this will be the record version of the project’s Worksheet. Save the Worksheet to the project’s ProjectWise 310_Milestone_ Submissions/100% folder. DC1. Water Quality Volume (WQV) retention design goal (acre-feet) – Determine the WQV retention design goal by first calculating the Water Quality Volume (WQV) for the project. The WQV is the volume of runoff generated across a site by one inch (1”) of rainfall. The proposed impervious area (C > 0.7) must be known to determine the WQV. WQV = (1-inch)(R)(A)/12 WQV = water quality volume (ac-ft) R = volumetric runoff coefficient = 0.05+0.009(I) I = percent impervious cover for post-construction condition as designed (C > 0.7). A = Total DOT-Owned Project Area in acres. Designer Insight - The percent impervious cover (I) in the calculation above is the total impervious area, not just that which is directly connected. This is different from the DCIA area computed for the existing condition (EC2), which excludes surfaces that do not drain to a wetland or watercourse directly or via a storm sewer discharge. CT DOT MS4 Project Design MEP Worksheet Instructions Page 4 of 7 Ver 3 .2020-02-26 Section 3: Designed Conditions (continued) The equation above calculates a retention volume based on 1” of rainfall. It is not necessarily the WQV goal for the project. The project’s WQV retention design goal is determined based on the percentage of DCIA at the pre-construction stage (EC2). If the pre- construction DCIA is greater or equal to 40% of the project area, then project’s retention goal will be ½ x Water Quality Volume (WQV). If the preconstruction DCIA is less than 40%, then the retention goal will be 1.0xWQV, or simply the WQV. For many redevelopment projects, the pre-construction DCIA percentage will be above 40% and the retention design goal will be equal to ½ the WQV. Designer insight – Designers should note that the Construction Stormwater General Permit bases the WQV goal on the project’s percentage of total impervious area. The DOT’s MS4 Permit uses the percentage of directly connected impervious area to determine the WQV goal. This difference means some projects will require retention/treatment of ½ the WQV for the Construction Permit but the full WQV for compliance with the MS4 Permit. If possible, an estimate of the retention goal should be calculated during preliminary design in order to approximate the extent of best management practices that will be needed. If the extent of impervious cover is not fully known by Design Approval, then the WQV cannot be calculated and the TBD box should be checked. Provide the information during a later design phase. An accurate value must always be provided for the FDP milestone. DC2. WQV Goal Retained – Copy the total WQV Retained value column in Section 4: Stormwater BMP Selection Summary. Refer to Section 4 of these instructions. DC3. WQV Goal Treated – Copy the total WQV Treated value column in Section 4: Stormwater BMP Selection Summary. Refer to Section 4 of these instructions. Designer insight – Incorporate run-off retention BMPs to the maximum extent practical as site conditions allow, documenting site constraints on page 2 that are consistent with the Existing Condition information provided on page 1. If the amount of run-off retained in the design condition fails to meet the WQV retention design goal (DC1), determine the shortfall and evaluate the use of treatment BMPs to make up the difference. Treatment without infiltration should only be incorporated into the design when runoff retention can be demonstrated to be unfeasible. Designer insight - It is acceptable to take credit for disconnecting off site DCIA areas that drain to on-site BMPs. DC4. Total WQV Retained or Treated – Add the WQV Retained per 1” of Rainfall (DC2) to the WQV Treated (DC3) and indicate the total. Designer insight – The Total WQV Retained or Treated is compared to the WQV retention design goal (DC1) to determine if the project has met the intended run-off reduction target. If DC4 is less than DC1, review any adjoining DOT ROW beyond the project limits (identified in EC9) where retention BMPs (primarily) or treatment BMPs (secondarily) could be constructed in order to meet the full WQV retention design goal (DC1). Incorporate the retention/treatment of the alternative site(s) and update page 2. If DC4 is still less than DC 1 after evaluating alternative sites and incorporating BMPs outside the project limits, then describe any limiting factors that make alternative locations unfeasible for BMPs in the Notes box on the bottom of page 1. Review the limiting site constraints in Section 4 with Section 1: Existing Conditions for accuracy and consistency. Designer insight – For projects that do not meet the required WQV retention design goal, the MS4 Program will be evaluating future water quality improvement projects within the same local drainage basins or in other priority areas to mitigate the shortfall from the original project. CT DOT MS4 Project Design MEP Worksheet Instructions Page 5 of 7 Ver 3 .2020-02-26 Section 3: Designed Conditions (continued) DC5. Post-construction DCIA (acres) – Determine the amount of post-construction DCIA. Here, DCIA is surface area within the project limits that a) is impervious and b) drains to a wetland or watercourse either directly or via a storm sewer system discharge. Impervious cover includes pavement, sidewalks, roofs (Facilities projects), exposed ledge, gravel roads/parking (C > 0.7). Do not include turf, temporary pavement areas or temporary access roads. If the post-construction DCIA is unknown during the Preliminary Design phase, check TBD and provide the information at a later design phase. Designer insight – For the Post-Construction DCIA value, do not count impervious areas that will drain to BMPs designed to retain and/or treat enough runoff for the area to have met the WQV retention design goal. Areas not directed to a qualifying BMP must be counted as DCIA. The goal is to reduce the amount of DCIA (see DC7 , below.) DC6. Pre-construction DCIA (acres) – Copy the Pre- Construction DOT-Owned Directly Connected Impervious Area (DCIA) from line EC2. DC7. Change in DCIA from pre- to post-construction (acres) - Subtract the Pre-construction DCIA (DC6) from the Post-construction directly connected impervious area (DC5). A negative value indicates that the amount of DCIA will decrease. A positive value indicates that the project will cause DCIA to increase. Review the limiting site constraints in Section 4 with the recorded existing conditions in Section 1 for accuracy and consistency. Designer insight – The DOT MS4 General Permit has a statewide compliance metric to reduce DOT DCIA by 2% within five years compared to a July 2019 baseline. While a project will not be in violation if the maximum extent practical falls short of the permit requirements for DCIA and runoff reductions, any additional DCIA added by projects will make meeting the 2%-reduction that much harder. Designer insight – Since BMPs may have drainage areas that extend beyond the chosen project area, it is acceptable to take credit for disconnecting off site DCIA areas that drain to on-site BMPs and compensate for DCIA remaining on-site. In rare cases it will be possible to disconnect more DCIA than exists within the project area. Section 4: Stormwater BMP Selection Summary This section of the Worksheet is intended to present the designer with several specific BMP types that are expected to be the most feasible for transportation- related projects. Refer to the CTDEEP’s 2004 Connecticut Stormwater Quality Manual for other acceptable BMPs and their respective design criteria. Innovative BMPs not listed in the Connecticut Stormwater Quality Manual are also encouraged so long as good engineering judgement is used when assigning retention and treatment capacities. Designer insight – Designers can refer to the BMP one pagers and the examples that have been prepared on various BMPs for guidance on their design. The examples include Natural Dispersion, Grass Channel , Check Dam (Supplemental), Infiltration Trench and Infiltration Basin. The key metrics associated with a stormwater quality design are tracked by the Worksheet as the project’s design progresses. Complete the Stormwater BMP Selection Summary at each milestone design review. Indicate the current design review phase by checking off the appropriate box in the upper left corner. Designer insight – While Section 3 (Design Conditions) and Section 4 (Stormwater BMP Selection Summary) were established based on a typical 30/60/90/FDP design process, it is understood that not every project will follow this exact design process and that a project’s metrics may not change from one phase to the next. At the project’s Design Approval, potential opportunities to improve water quality with stormwater BMPs should be identified with preliminary locations shown on project plans. Design phases after Design Approval will need to verify any preliminary assumptions used in siting and sizing BMPs. Examine all limiting factors for each BMP (see Site Constraints for each type of stormwater management measure listed on the designer worksheet). CT DOT MS4 Project Design MEP Worksheet Instructions Page 6 of 7 Ver 3 .2020-02-26 Section 4: Stormwater BMP Selection Summary (continued)  Permeability/percolation information  Depth to maximum groundwater  Depth to bedrock Update Section 1 as needed based on the field investigations. Designer insight – A best management practice that does not meet every design requirement listed in the Stormwater Quality Manual will still provide a benefit, albeit not the full possible extent. Document the assumptions used in determining the proportional amount of runoff retainage and/or treatment that the BMP will provide given its site constraints. The BMPs listed under the Stormwater BMP Selection Summary are grouped into four categories: 1. Disconnection BMPs promote flow dispersion and reduce flow velocities in order to allow the downstream terrain to absorb and/or filter the runoff. Consider the following factors of the downstream terrain when determining its capacity to retain or treat: slope, soil type, and distance to the nearest surface water or wetland. Consider augmenting the downstream terrain to retain or treat a greater volume of runoff. For example, soil amendments can be used to increase infiltration capacity or certain seed mixes could be specified to promote beneficial vegetation. 2. Conveyance & Disconnection BMPs remove pollutants from the runoff as it is collected and conveyed away from the transportation infrastructure. The slope, soil type, and length of the conveyance will generally dictate its capacity to retain and/or treat. Also consider the downstream terrain, if any, between the conveyance’s outfall and the nearest surface water or wetland. Designer insight – For a Disconnection BMPs and Conveyance & Disconnection BMPs to meet the WQV retention design goal, they may need to be coupled with one or more other BMPs designed per the criteria in the CT DEEP Stormwater Quality Manual. 3. Infiltration/Retention BMPs are practices that retain the WQV or a portion of the WQV, temporarily holding it before it infiltrates into the native soil. Any BMP that does not allow the WQV from entering a storm system or adjacent surface water body would qualify for infiltration/retention credit. 4. Treatment BMPs are practices that improve the water quality but do not reduce or retain the volume. WQV Retained – In this column, list the amount of the WQV retained by each BMP used in the design. For example, if a project uses three separate infiltration trenches then each trench should be individually listed (under in the infiltration/retention section) and the WQV retained by each recorded in the cell where the “infiltration trench” row and the “WQV Retained” column intersect. WQV Treated – In this column, list the amount of the WQV treated by each BMP used in the design. For example, if a project has incorporated two separate wet detention basins then each basin should be individually listed (under the “treatment” section) and the volume treated by each basin should be recorded in the cell where the “wet basin” row and the “WQV Treated” column intersect. Designer insight – The amount of water that a Disconnection BMP or a Conveyance & Disconnection BMP can infiltrate might be limited to only a portion of the WQV retention design goal. In additional to infiltration, consider the amount of treatment the BMP provides to the portion of the WQV that cannot be retained. Include the amount of treatment under the WQV Treated column. CT DOT MS4 Project Design MEP Worksheet Instructions Page 7 of 7 Ver 3 .2020-02-26 Section 4: Stormwater BMP Selection Summary (continued) DCIA Captured (acres) – In this column, list the amount of directly connected impervious area (DCIA) that is captured by the BMP being proposed. DCIA Captured is the amount of surface area within the project limits that a) is impervious and b) drains to a BMP for retention and/or treatment that would otherwise of drained to a wetland or watercourse either directly or via a storm sewer system discharge. DCIA Disconnection Credit (Percentage) – In this column, record the DCIA Disconnection Credit for the proposed BMP. DCIA Disconnection Credit is the percentage of DCIA directed to a BMP that can be considered disconnected. To find the DCIA Disconnection Credit percentage for different BMPs refer to the BMP one pagers which can be found on the CTDOT MS4 Webpage. (https://portal.ct.gov/DOT/PP_Envir/Water_Natural_Re sources/CTDOT-MS4) DCIA Disconnection Credit (Acres) – DCIA Disconnection Credit is the area directed to a BMP that can be considered disconnected. To find this number multiply the total amount of DCIA Captured (acres) by the DCIA Disconnection Credit percentage of the BMP. Site Constraints: For each of the four categories of BMPs, select one or more site constraint from the drop down boxes. Site constraints are characteristics of the project location that prevent the selection of the corresponding type of BMP in the project’s design. Selected site constraints must be consistent with the information provided in Section 2. Designer insight – If a BMP is included into a project, and if the WQV design retention goal is met (see Section 3), then a Site Constraint does not need to be selected for that BMP’s category. Every project that affects drainage shall at least have completed the Worksheet with its FDP. The FDP-version will be considered the final version of the worksheet. All metrics extracted for the annual DEEP reports will come from the final FDP Worksheet. Save the FDP version of the Worksheet to the project’s ProjectWise 310_Milestone_ Submissions/100% folder. Worksheet users should refer to the CT DOT MS4 Project Design MEP Worksheet Instructions CTDOT MS4 Design MEP Worksheet Version 3 Revised 2/26/2020 Page 1 of 2 CTDOT MS4 Project Design Maximum Extent Practicable (MEP) Worksheet Section 1: Project Information Project #: Title: Location: Section 2: Existing Conditions EC1 Total Project Area acres EC2 Pre-construction Directly Connected Impervious Area (DCIA): acres EC3 Soil Infiltration Potential Data Source: ☐Existing Report / Soils Map ☐Field Verified ☐Good/Fair ☐Poor ☐Mixed EC4 Depth to Maximum Groundwater ☐TBD to ft below grade EC5 Depth to Bedrock ☐TBD to ft below grade EC6 Aquifer Protection Area? (from PNDF) ☐Yes ☐No EC7 MS4 Priority Area? (from PNDF) ☐Yes (See Below) ☐No Check All That Apply ☐Urbanized Area ☐DCIA >11% ☐Impaired Waterbody (See Below) Select All Impairments That Apply EC8 Contamination known or suspected to be present? (From Environmental Compliance) ☐Yes ☐No EC9 Adjoining DOT ROW beyond project limits available for stormwater quality management acres Section 3: Designed Conditions Water Quality Calculations 30% Design 60% Design 90% Design FDP DC1 WQV retention design goal ac-ft ☐ TBD ac-ft ac-ft ac-ft DC2 WQV goal retained (refer to page 2) ac-ft ac-ft ac-ft ac-ft DC3 WQV goal treated (refer to page 2) ac-ft ac-ft ac-ft ac-ft DC Total WQV retained and treated ac-ft ac-ft ac-ft ac-ft DC5 Post-construction DCIA(acres) ac. ☐ TBD ac. ac. ac. DC6 Pre-construction DCIA (refer to EC2 above) ac. ac. ac. ac. DC7 Change in DCIA from pre- to post-construction Can be positive (DCIA gained) or negative (DCIA lost) ac. ☐ TBD ac. ac. ac. Date completed Completed by (initials) Reviewed by (initials) Notes: % 4 Full 1/2"-WQV Worksheet users should refer to the CT DOT MS4 Project Design MEP Worksheet Instructions. Refer to the 2004 CT Stormwater Quality Manual for more information on BMP criteria and limitations. CTDOT MS4 Design MEP Worksheet Version 3 Revised 2/26/2020 CTDOT MS4 Design MEP Worksheet Version 3 Revised 2/26/2020 Page 2 of 2 Section 4: Stormwater BMP Selection Summary Design Phase ☐30% ☐60% ☐90% ☐FDP WQV Retained (ac-ft) WQV Treated (ac-ft) DCIA Captured (Acres) DCIA Disconnection Credit (%) DCIA Disconnection Credit (acres) Site Constraints Disconnection (Dispersion) Conveyance (Swales / Channels) Infiltration / Retention Treatment TOTAL Notes: APPENDIX E Construction Site Environmental Inspection Report (CSEIR) State of Connecticut Department of Transportation Construction Site Environmental Inspection Report TThhiiss FFoorrmm MMuusstt BBee CCoommpplleetteedd AAtt LLeeaasstt OOnnccee AA WWeeeekk AAnndd WWiitthhiinn TTwweennttyy FFoouurr ((2244)) HHoouurrss OOff TThhee EEnndd OOff AA SSttoorrmm EEvveenntt TThhaatt IIss 00..11 iinncchheess OOrr GGrreeaatteerr General Information Project Number Date Permit Number(s) Location Phone No. Project Engineer Chief Inspector Contractor Describe present phase of construction/activities that are occurring Type of Inspection: Weekly Pre-storm event During storm event Post-storm event Weather Information Has there been a storm event since the last inspection? Yes No If yes, provide: Storm Start Date & Time: Storm Duration (hrs): Type and Approximate Amount of Precipitation (in): Weather at time of this inspection? Clear Cloudy Rain Sleet Fog Snowing High Winds Temperature: Site-specific BMPs  Number the structural and non-structural BMPs on your site map and list them below (add as many BMPs as necessary). Carry a copy of the numbered site map for reference with you during your inspections. BMP Maintenance BMP or Observation Site and Location BMPs Installed ? BMP Maintenance Required? Remedial Action Required and Date Contractor was Notified *ALL REMEDIAL ACTIONS MUST BE COMPLETED WITHIN 24 HOURS* Date Fixed Photo Taken ? Repeat Failure? 1 Yes No Yes No Yes No Yes No 2 Yes No Yes No Yes No Yes No 3 Yes No Yes No Yes No Yes No Environmental Inspector: Signature: Date: Reviewed by: Signature: Date: Are there any sediment discharges to a regulated area occurring or have any occurred since the last inspection? Yes No IIff yyeess,, ccoonnttaacctt tthhee DDiissttrriicctt EEnnvviirroonnmmeennttaall CCoooorrddiinnaattoorr iimmmmeeddiiaatteellyy.. Describe the discharge including location, time identified, and the approximate amount of sediment. (on back) APPENDIX F Notice of Termination Form Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 1 of 7 Rev. 01/05/2022 General Permit for the Discharge of Stormwater and Dewatering Wastewaters from Construction Activities Notice of Termination Form: Non-Solar Projects This Notice serves as a request to terminate the below listed permit as well as any applicable Letter(s) of Credit. Part I: Permittee Information The below information is required in accordance with Section 6(b) of the General Permit. 1. Permit Number: GSN 2. Registrant: 3. Site Address: City/Town: State: Zip Code: 4. Date of completion of construction: Date all storm drainage structures were cleared of construction sediment and debris: Beginning and Ending Dates of post-construction inspections: Date of final stabilization inspection(s)*: Qualified Inspector who conducted the Final Stabilization Inspection: (This person must sign Part III) 5. Check the post-construction activity(ies)** at the site (check all that apply): ☐Industrial ☐ Residential ☐ Capped Landfill ☐ Commercial ☐ Solar Array ☐ Other: * The Final Stabilization Inspection must occur at least one full growing season after final stabilization has been achieved. A full growing season is defined as the timeframe encompassed by two consecutive full seeding seasons: April 1 through June 15, and August 15 through October 1. If final stabilization is achieved during a seeding season, the following seeding season will be considered the first full seeding season after final stabilization has been achieved. ** If the post-construction activity involves solar arrays, the Department may require that the “Solar Projects: Notice of Termination Form” be used. Any questions regarding the necessity of such a form for the project can be sent via email to DEEP.StormwaterStaff@ct.gov. Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 2 of 7 Rev. 01/05/2022 Locally Approvable Projects Must Complete the following Part II - (Attach additional sheets as needed) Part II: Locally Approvable Post-Construction Inspection Certification The below information is required in accordance with Section 5(b)(4)(C)(i) of the General Permit. Certification by a Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional / District Representative “I hereby certify that I am a qualified professional engineer / a qualified soil erosion and sediment control professional / a representative of the District in which the site is located as defined in Section 2 of the General Permit for Discharge of Stormwater and Dewatering Wastewaters from Construction Activities (general permit). I am familiar with the site described in this Notice of Termination and the requirements of the general permit. I certify, based on my personal inspection of the site pursuant to Section 6(a) of the general permit that all post- construction measures have been installed as specified in the permittee’s Stormwater Pollution Control Plan and in accordance with Section 5(b)(2)(C) of the general permit and that all such measures have been cleaned of construction sediment and debris. I understand that this certification is part of a registration submitted in accordance with section 22a-430b of Connecticut General Statutes and is subject to the requirements and responsibilities for a qualified professional in such statute. I also understand that knowingly making any false statement in this certification may be punishable as a criminal offense, including the possibility of fine and imprisonment, under section 53a-157b of the Connecticut General Statutes and any other applicable law.” Signature of Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional / Representative of the District Date Printed Name of Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional / Representative of the District Title Check off the qualifications of the signatory of the above part: ☐ Qualified Professional Engineer ☐ Qualified Soil Erosion and Sediment Control Professional ☐ Representative of the District Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 3 of 7 Rev. 01/05/2022 Locally Exempt Projects Must Complete the following Part II - (Attach additional sheets as needed) Part II: Locally Exempt Post-Construction Inspection Certification The below information is required in accordance with Section 5(b)(4)(C)(ii) of the General Permit. Certification by a Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional “I hereby certify that I am a qualified professional engineer / a qualified soil erosion and sediment control professional as defined in Section 2 of the General Permit for Discharge of Stormwater and Dewatering Wastewaters from Construction Activities (general permit). I am familiar with the site described in this Notice of Termination and the requirements of the general permit. I certify, based on my personal inspection of the site pursuant to Section 6(a) of the general permit that all post-construction measures have been installed as specified in the permittee’s Stormwater Pollution Control Plan and in accordance with Section 5(b)(2)(C) of the general permit and that all such measures have been cleaned of construction sediment and debris. I understand that this certification is part of a registration submitted in accordance with section 22a-430b of Connecticut General Statutes and is subject to the requirements and responsibilities for a qualified professional in such statute. I also understand that knowingly making any false statement in this certification may be punishable as a criminal offense, including the possibility of fine and imprisonment, under section 53a-157b of the Connecticut General Statutes and any other applicable law.” Signature of Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional Date Printed Name of Qualified Professional Engineer / Qualified Soil Erosion and Sediment Control Professional Title Check off the qualifications of the signatory of the above part: ☐ Qualified Professional Engineer ☐ Qualified Soil Erosion and Sediment Control Professional Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 4 of 7 Rev. 01/05/2022 State Agency Projects Must Complete the following Part II - (Attach additional sheets as needed) Part II: State Agency Post-Construction Inspection Certification The below information is required in accordance with Section 5(b)(4)(C)(iii) of the General Permit. Certification by a DOT District Engineer or his/her designee / a DOT District Environmental Coordinator / a designated employee of another state agency “I hereby certify that I am a DOT District Engineer or his/her designee / a DOT District Environmental Coordinator / a designated employee of another state agency as defined in Section 2 of the General Permit for Discharge of Stormwater and Dewatering Wastewaters from Construction Activities (general permit). I am familiar with the site described in this Notice of Termination and the requirements of the general permit. I certify, based on my personal inspection of the site pursuant to Section 6(a) of the general permit that all post-construction measures have been installed as specified in the permittee’s Stormwater Pollution Control Plan and in accordance with Section 5(b)(2)(C) of the general permit and that all such measures have been cleaned of construction sediment and debris. I understand that this certification is part of a registration submitted in accordance with section 22a-430b of Connecticut General Statutes and is subject to the requirements and responsibilities for a qualified professional in such statute. I also understand that knowingly making any false statement in this certification may be punishable as a criminal offense, including the possibility of fine and imprisonment, under section 53a-157b of the Connecticut General Statutes and any other applicable law.” Signature Date Printed Name Title Check off the qualifications of the signatory of the above part: ☐ Qualified Professional Engineer ☐ Qualified Soil Erosion and Sediment Control Professional ☐ Representative of the District Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 5 of 7 Rev. 01/05/2022 All Projects Must Complete the following Part III - (Attach additional sheets as needed) Part III: Final Stabilization Inspection Certification The below information is required in accordance with Section 5(b)(4)(D) of the General Permit. Certification by a Qualified Inspector “I hereby certify that I am a qualified inspector as defined in Section 2 of the General Permit for Discharge of Stormwater and Dewatering Wastewaters from Construction Activities (general permit). I am familiar with the site described in this Notice of Termination and the requirements of the general permit. I certify, based on my personal inspection of the site pursuant to Section 6(a) of the general permit that the site has been stabilized, as defined in Section 2 of the general permit, for a period of no less than one full growing season following the cessation of construction activities. I further certify that there is no active erosion or sedimentation present on site and no disturbed areas remain exposed. I also understand that knowingly making any false statement in this certification may be punishable as a criminal offense, including the possibility of fine and imprisonment, under section 53a-157b of the Connecticut General Statutes and any other applicable law.” Signature of Qualified Inspector Date Printed Name of Qualified Inspector Title Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 6 of 7 Rev. 01/05/2022 All Projects Must Complete the following Part IV - (Attach additional sheets as needed) Part IV: Permittee Certification The below information is required in accordance with Section 5(b)(4)(D) of the General Permit. Certification by the Permittee “I have personally examined and am familiar with the information submitted in this document and all attachments thereto, and I certify that, based on reasonable investigation, including my inquiry of those individuals responsible for obtaining the information, the submitted information is true, accurate and complete to the best of my knowledge and belief. I understand that a false statement made in this document or its attachments may be punishable as a criminal offense, in accordance with section 22a-6 of the Connecticut General Statutes, pursuant to section 53a-157b of the Connecticut General Statutes, and in accordance with any other applicable statute.” Signature of Permittee Date Printed Name of Permittee Title Bureau of Materials Management & Compliance Assurance DEEP-WPED-NOT-015a Page 7 of 7 Rev. 01/05/2022 All Projects Must Complete the following Part V - (Attach additional documentation as needed) Part V: Additional Submittals The following attachments are required to be submitted along with the Notice of Termination Form: ☐ Post-Construction Inspection Report (must contain photos with time stamps) ☐ Final Stabilization Inspection Report (must contain photos with time stamps) Complete and submit this form in accordance with the general permit (DEEP-WPED-GP-015) to ensure the proper handling of the termination. Print or type unless otherwise noted. Submit this Notice of Termination Form to the address below, as well as via email to DEEP.StormwaterStaff@ct.gov: WATER PERMITTING AND ENFORCEMENT DIVISION/STORMWATER GROUP DEPARTMENT OF ENERGY & ENVIRONMENTAL PROTECTION 79 ELM STREET HARTFORD, CT 06106-5127 APPENDIX D Operation and Maintenance Plan (O & M Plan) Operation & Maintenance Plan Horizon View 2268-2284 Route 32 Montville CT 06353 Prepared for: Honeycomb Real Estate Partners 20 Avon Meadow Lane Avon, CT 06001 Prepared by: R.J. O’Connell & Associates, Inc. 80 Montvale Ave, Suite 201 Stoneham, MA 02180 Date: September 25, 2024 TABLE OF CONTENTS Introduction Section 1 – Stormwater Management System - Operations and Maintenance Section 2 – Long Term Pollution Prevention Plan (LTPPP) A. Materials Covered B. Materials Management Practices C. Spill Prevention and Response Procedures Section 3 – Illicit Discharge Statement Section 4 – Snow Management Appendices Appendix A – Maintenance and Inspection Forms Activity Guide Comprehensive Annual Evaluation and Inspection Report Annual Training Signoff Sheet Weekly Inspection Checklist Monthly Inspection Checklist Quarterly Inspection Checklist Semi-Annual Inspection Checklist Spill and Leak History Appendix B – C-2 – Grading and Drainage Plan BMP-1 - BMP Location Plan Appendix C – CDS Stormwater Treatment Unit Operation and Maintenance Guidelines Operations and Maintenance Plan INTRODUCTION This Operations and Maintenance Plan has been prepared to ensure that the stormwater management system implemented at 2268-2284 Route 32 located in Montville, Connecticut functions as designed. It will develop and carry out suitable practices for source control and pollution prevention. It describes the various components of the stormwater management system, identifies the inspection and maintenance tasks to be undertaken after construction is complete, and establishes a schedule for implementing these tasks to ensure the proper, long-term operation of the system. SECTION 1 - STORMWATER MANAGEMENT SYSTEM- OPERATION AND MAINTENANCE The objectives of the stormwater management system are to effectively control and treat stormwater runoff from the site in accordance with the Connecticut stormwater management standards. To accomplish this objective, the following Best Management Practices (BMP’s) are included in the stormwater management system: BMPs • Installation and maintenance of the catch basins with deep sumps and hoods to reduce the discharge of sediment and pollutants. • Installation of a subsurface infiltration system to provide the required recharge of groundwater. In consideration of the foregoing, it is the ongoing responsibility of the landowner, their successors and assignees, to adequately maintain the on-site stormwater management BMPs. Adequate maintenance is herein defined as good working condition so that these BMPs are performing their design functions. Based on this, the landowner, successors and assignees are required to create a Pollution Prevention Team (PPT) that will be responsible for implementing this Operations and Maintenance Plan. Upon transfer of ownership of the property, the landowner is required to notify the new owner of the presence of the stormwater management system and the requirements of this Operations and Maintenance Plan. Property Information Address: 2268-2284 Route 32 Montville, Connecticut Landowner and Pollution Prevention Team Leader Owners Name: TBD Owner Contact: TBD Title: Owner and Operator: TBD Phone: TBD Email: TBD Responsibilities: Coordinate all aspects of the Operations and Maintenance Plan, coordinate and hire the other Pollution Prevention team members in order to conduct inspections, keep all records, and coordinate with contractors for maintenance and repair of the stormwater management system. Spill Prevention & Control Contractor The following contacts shall be notified only in those instances identified within Connecticut General Statutes (CGS) Chapter 446K Section 22a-450 (see Section 2 - Long-Term Pollution Prevention Plan).: Primary Contact: Office Phone: Emergency Contact: Company Name: Contact Name: Emergency Phone: Consultant Contact: Company Name: Contact Name: Phone: CT Department of Energy and Environmental Protection (DEEP) Emergency Response Triage Contact Name: Phone: Municipal Contacts Montville Fire Department Contact Name: Paul Barnes, Fire Marshal Phone: (860) 848-6781 Montville Public Works Contact Name: John Carlson, Public Works Director Phone: (860) 848-7473 Other Pollution Prevention Team Members Member: Responsibilities: Conduct scheduled inspections, maintain records, advise the Team Leader of maintenance needs, ensure inspection maintenance and repairs are completed and keep and maintain all records and inspection reports. Company Name(s): Address: Office Phone: Team Member Training The Pollution Prevention Team Leader will coordinate an annual in-house training session with the qualified Engineering and/or Environmental Consulting Firm to discuss the Operations and Maintenance Plan, ongoing inspection and maintenance and preventative maintenance procedures. Annual training session will generally include the following: • Discuss the Operations and Maintenance Plan o What it is- identify potential sources of stormwater pollution and methods of reducing or eliminating that pollution o What it contains- emphasize good housekeeping measures and location of potential pollution sources. o Pollution Prevention Team- introduce the team and explain their responsibilities, explain the operations and continuous monitoring of the stormwater management system and encourage input and assistance from all. • Review and explain the storm drainage system, how it works and its components, note the receiving resource area in which the storm drainage system discharges into and the role each component plays. • Emphasize the importance of maintaining current and up-to-date inspection reports and maintenance records of BMPs. Documentation shall include any changes to the O&M Plan’s procedures to accommodate changes and revisions to BMPs. The components of the stormwater management system must be inspected, monitored, and maintained in accordance with the following to ensure that the on-site stormwater management BMPs are functioning as designed. Routine inspection and proper maintenance of these individual components is essential to providing the long-term enhancement of both the quality and quantity of the runoff from the properties. Deep Sump Catch Basins: Stormwater runoff from pavement areas is directed to catch basins via site grading and curbing. Catch basins are equipped with a deep (4 ft) sump and a hood. The sumps are designed to capture sediment and coarse particles, and the hoods prevent hydrocarbons and other floatable debris from entering the drainage system. To ensure proper functioning of catch basins, each will be inspected and maintained as follows: Inspection: Beginning of March, June, September, December and after major storm events. Structural damage and other malfunctions are to be noted and reported. Basins shall also be inspected during every major rain event (3.1 inches or greater in 24 hours) to ensure the grates are not clogged and are functioning properly. Maintenance: Catch basins are to be pumped and cleaned at a minimum once a year in the springtime, or when the sumps are half full. The cleaning shall be performed by a licensed contractor. Sediment and hydrocarbons will be properly handled and legally disposed of off-site in accordance with local, state, and federal guidelines and regulations. Any structural damage to catch basins and/or castings will be repaired upon discovery. Subsurface Infiltration System A subsurface infiltration system consists of perforated corrugated metal pipes (CMPs) placed underground that temporarily retain a portion of stormwater runoff and allow it to infiltrate into the ground thereby recharging the groundwater. Inspection: Inspect inlets twice annually for sediment accumulation, trash and clogging. Remove any sediment and/or debris buildup at the inlet and outlet of the system during each inspection. Maintenance: The subsurface retention system shall be maintained once a year. Remove any debris and sediment that might clog the system. Outlet Control Structures: The outlet control structures are pre-cast concrete manholes located downstream of the subsurface infiltration system and contains various configurations of orifices that regulate the rate of stormwater discharge from the subsurface infiltration system. The outlet control structure shall be inspected and maintained as follows: Inspection: Structures must be inspected annually. Check the outlet control structures for sediment and debris accumulation and any structural damage. Maintenance: Structures must be jet vacuumed and power washed by a licensed contractor at least once per year. Accumulated sediment will be disposed on in accordance with applicable local, state and federal guidelines and regulations. Wetland Maintenance Activities: Maintenance activities such as sediment removal, mowing, and repairs should be performed with rakes and light-weight equipment rather than heavy construction equipment to avoid soil compaction and damage to vegetation. Heavy equipment may be used for sediment removal and other maintenance activities if the equipment is positioned outside the limits of the system. Heavy construction equipment should not be allowed within the limits of the system for maintenance purposes. Recommended wetland maintenance activities should include the following: • Inspect after major storms (1 inch or more of precipitation) in the first few months following construction. • Inspect sediment forebay twice per year and the rest of the system annually, including inlet and outlet control structures. • Refer to Appendix B for maintenance inspection checklists, including items to focus on during the inspection. • Remove trach and organic debris (leaves) in the spring and fall. • Remove sediment from the forebay or other pretreatment areas when it accumulates to a depth of more than 24 inches or 50% of the design depth. • Remove sediment from the permanent pool when volume has become reduced significantly, or when significant algal growth is observed. • The vegetative cover should be maintained at 85%. If vegetation has damage, the area should be reestablished in accordance with the original specifications. • Prune wetland vegetation on a regular schedule. Inspect wetland plants and manage/harvest dead or dying plants as necessary. Plant reinforcement plantings as necessary. • Periodically mow perimeter grass during the growing season. Maintain perimeter grass at 6 inches or higher. High grass along the wetland edge will discourage waterfowl from taking up residence and serve to filter pollutants. • Inspect and remove invasive vegetation as necessary. • Remove trees and woody vegetation within 25 feet of all risers, pipe outlet structures, spillways, and downstream embankments that hold back water. • Prune other woody vegetation where dead or dying branches are observed. Please refer to Appendix A for the Inspection Forms, which are to be used by the Pollution Prevention Team member responsible for conducting the scheduled inspections. SECTION 2 - LONG TERM POLLUTION PREVENTION PLAN (LTPPP) A. MATERIALS COVERED The following materials or substances are expected to be present onsite after construction: Cleaning solvents Petroleum based products Detergents Pesticides/Insecticides Paints/Solvents Fertilizers/Herbicides Acids Contaminated Soil Solid Waste B. MATERIALS MANAGEMENT PRACTICES The following are the material management practices that will be used to reduce the risk of spills or other accidental exposure of materials and substances to stormwater runoff. The Pollution Prevention Team Leader will be responsible for ensuring that these procedures are followed: 1. Good Housekeeping The following good housekeeping practices will be followed onsite after construction: a) An effort will be made to store only enough products required to do the job. b) All materials stored onsite will be stored in a neat, orderly manner and, if possible, under a roof or in a containment area. At a minimum, all containers will be stored with their lids on when not in use. Drip pans shall be provided under all dispensers. c) Products will be kept in their original containers with the original manufacturer's label in legible condition. d) Substances will not be mixed with one another unless recommended by the manufacturer. e) Whenever possible, the product will be used up entirely before disposing of the container. f) Manufacturer's recommendations for proper use and disposal will be followed. g) A Pollution Prevention Team Member will be responsible for daily inspections to ensure proper use and disposal of materials. h) The storage of all deicing materials on the site shall be covered and not be exposed to precipitation. 2. Hazardous Substances These practices will be used to reduce the risks associated with hazardous substances. Material Safety Data Sheets (MSDS's) for each product with hazardous characteristics that are used on the property will be obtained and used for the proper management of potential wastes that may result from these products. An MSDS will be posted in the immediate area where such product is stored and/or used and another copy of each MSDS will be maintained on-site, in the management office. Each employee who must handle a hazardous substance will be instructed on the use of MSDS sheets and the specific information in the applicable MSDS for the product they are using, particularly regarding spill control techniques. a) Products will be kept in original containers with the original labels in legible condition. b) Original labels and MSDS's will be procured and used for each product. c) If surplus product must be disposed of, the manufacturer's and local/state/federal required methods for proper disposal must be followed. 3. Hazardous Waste It is imperative that all hazardous waste be properly identified and handled in accordance with all applicable hazardous waste standards, including the storage, transport and disposal of the hazardous wastes. There are significant penalties for the improper handling of hazardous waste. It is important that the Pollution Prevention Team Leader seeks appropriate assistance in making the determination of whether a substance or material is a hazardous waste. For example, hazardous waste may include certain hazardous substances, as well as pesticides, paints, paint solvents, cleaning solvents, contaminated soils, and other materials, substances or chemicals that have been discarded (or are to be discarded) as being out-of-date, contaminated, or otherwise unusable. The Pollution Prevention Team Leader is responsible for ensuring that all Pollution Prevention Team Members are instructed as to these hazardous waste requirements as well as that the requirements for handling and disposal are being followed. 4. Product Specific Practices The following product specific practices will be followed on the job site: a) Petroleum Products Petroleum products will be stored in tightly sealed containers which are clearly labeled. Petroleum storage tanks shall be located a minimum of 100 linear feet from wetland resource areas, drainage ways, inlets and surface waters unless stored within a building. Any petroleum storage tanks stored onsite will be located within a containment area that is designed with an impervious surface between the tank and the ground. The secondary containment must be designed to provide a containment volume that is equal to 110% of the volume of the largest tank. Drip pans shall be provided for all dispensers. Any asphalt substances used onsite will be applied according to the manufacturer's recommendations. The location of any fuel tanks and/or equipment storage areas must be identified on the Erosion Control Plan by the Contractor once the locations have been determined. b) Fertilizers, Herbicides, Pesticides, and Insecticides Fertilizers, herbicides, pesticides, and insecticides shall be applied only in the minimum amounts recommended by the manufacturer. Once applied, they shall be utilized so as to limit exposure to stormwater. Storage will be in a covered shed. The contents of any partially used bags or containers will be transferred to a sealable plastic bin to avoid spills. Fertilizers shall not be applied within resource areas. Refer to Drawing C-2, Grading and Drainage Plan, for location of resource areas and buffer zones. c) Paints, Paint Solvents, and Cleaning Solvents All containers will be tightly sealed and stored when not in use. Excess paint and solvents will not be discharged to the storm sewer system but will be properly disposed of according to manufacturer's instructions or state and federal regulations. 5. Solid Waste All waste materials will be collected and stored in an appropriately covered container and/or securely contained metal dumpster rented from a local waste management company which must be a licensed solid waste management company. The dumpster will comply with all local and state solid waste management regulations. All trash and debris from the site will be deposited in dumpsters. The dumpsters will be emptied a minimum of once per week or more often if necessary. All personnel will be instructed regarding the correct procedures for waste disposal. All waste dumpsters and roll-off containers shall be located in an area where the likelihood of the containers contributing to stormwater discharges is negligible. 6. Contaminated Soils Any contaminated soils resulting from spills of hazardous substances or oil shall be contained and cleaned up immediately in accordance with the procedures given in the Materials Management Plan and in accordance with applicable state and federal regulations. If there is a release, it should be reported as a spill, if it otherwise meets the requirements for a reportable spill. C. SPILL PREVENTION AND RESPONSE PROCEDURES The Pollution Prevention Team Leader will train all personnel in the proper handling and cleanup of spilled hazardous substances or oil. No spilled hazardous substances or oil will be allowed to come in contact with stormwater discharges. If such contact occurs, the storm water discharge will be contained on site until appropriate measures in compliance with state and federal regulations are taken to dispose of such contaminated storm water. It shall be the responsibility of the Pollution Prevention Team Leader to be properly trained, and to train all personnel in spill prevention and clean up procedures. 1. In order to prevent or minimize the potential for a spill of hazardous substances or oil to come into contact with stormwater, the following steps shall be implemented: a) All hazardous substances or oil (such as pesticides, petroleum products, fertilizers, detergents, acids, paints, paint solvents, cleaning solvents, etc.) shall be stored in a secure location, with their lids on, preferably under cover, when not in use. b) The minimum practical quantity of all such materials shall be kept on site. c) A spill control and containment kit (containing, for example, absorbent materials, acid neutralizing powder, brooms, dust pans, mops, rags, gloves, goggles, plastic and metal trash containers, etc.) shall be provided on site. d) Manufacturer’s recommended methods for spill cleanup shall be clearly posted and site personnel shall be trained regarding these procedures and the location of the information and cleanup supplies. e) It is the Pollution Prevention Team Leader’s responsibility to ensure that all hazardous waste on site is disposed of properly by a licensed hazardous material disposal company. The Pollution Prevention Team Leader is responsible for not exceeding hazardous waste storage requirements mandated by the EPA or state and local authority. 2. In the event of a spill of hazardous substances or oil, the following procedures must be followed: a) All measures must be taken to contain and abate the spill and to prevent the discharge of the hazardous substance or oil to stormwater or off-site. (The spill area must be kept well ventilated and personnel must wear appropriate protective clothing to prevent injury from contact with the hazardous substances.) b) For spills of less than five (5) gallons of material, proceed with source control and containment, clean-up with absorbent materials or other applicable means unless an imminent hazard or other circumstances dictate that the spill should be treated by a professional emergency response contractor. c) For spills greater than five (5) gallons of material immediately contact the CT DEEP Emergency Response and Spill Prevention at (860) 424-3338, and an approved emergency response contractor. Provide information on the type of material spilled, the location of the spill, the quantity spilled, and the time of the spill to the emergency response contractor or coordinator, and proceed with prevention, containment and/or clean-up as safely deemed necessary. d) If there is a Reportable Quantity (RQ) release, then the National Response Center shall be notified immediately at (800) 424-8802; within 14 days a report will be submitted to the EPA regional office describing the release, the date and circumstances of the release and the steps taken to prevent another release. This Pollution Prevention Plan must be updated to reflect any such steps or actions taken and measures to prevent the same from reoccurring. 3. The Pollution Prevention Team Leader shall be the spill prevention and response coordinator. The Leader will designate the individuals who will receive spill prevention and response training. These individuals will each become responsible for a particular phase of prevention and response. The names of these personnel will be posted in the material storage area and in the management office. SECTION 3 - ILLICIT DISCHARGE STATEMENT Certain types of discharges are allowable under the U.S. Environmental Protection Agency Construction General Permit, and it is the intent of this Long Term Pollution Prevention Plan (LTPPP) to allow such discharges. These types of discharges will be allowed under the conditions that no pollutants will be allowed to come in contact with the water prior to, or after its discharge. The control measures which have been outlined previously in this LTPPP will be strictly followed to ensure that no contamination of these non-storm water discharges takes place. Illicit discharges, if they exist currently, shall be contained and eliminated in the manner specified by local, state and federal regulations, and will be prohibited in the proposed development. SECTION 4 – SNOW MANAGEMENT Snow management will be overseen by the Property Manager who will implement this plan and be authorized to utilize additional resources should unusual events occur. The Snow Management Contractor (SMC) shall be responsible for maintaining all roads, driveways, parking lots, sidewalks and pedestrian access areas for clear and safe travel. The SMC shall report directly to the Property Manager and maintain communication via cell phone 24 hours per day, 7 days per week. During extreme events, the first priority will be to clear and maintain proper access for residents and public safety vehicles. The next priority is parking areas, sidewalks, and fire hydrants. Snow shall not be piled around light bases or fire hydrants and handicap parking areas shall be cleared frequently. The anti-icing operations typically precede snow plowing and will be provided when conditions warrant. Within 12 months of concrete walks, pads, or other features being poured, no salt shall be placed on those surfaces. After the materials have cured for 12 months, a combination of calcium chloride deicers and sand (“washed”, fine to medium grade) shall be utilized. Parking areas shall receive spot treatment only when and where needed in a similar manner. Snow plowing shall commence upon accumulation of two (2”) inches or more. Snow shall be deposited in appropriate snow storage areas outside of the 100-foot wetland buffer and in locations that will minimize the impact to pedestrian access, vehicle circulation, and parking spaces. During extreme events, excess snow will be removed offsite as necessary. The SMC shall keep existing catch basins open for drainage or water resulting from melting. Once the storm is over, the SMC shall monitor all areas on-site for icy spots and snowdrifts. If necessary, an application of salt/sand mixture will be applied to all pavement areas so that the riding surface remains drivable. When the ambient temperature drops below 25 degrees Fahrenheit, all major areas shall receive an application of pre-wetted salt with calcium chloride to maintain melting action and ice-free surfaces for as long as possible. Salt loses its effectiveness as temperatures drop below 25 degrees Fahrenheit. De-icing chemicals shall be kept in original containers with the original product label in legible condition. When not in use, de-icing materials shall be stored in a neat, orderly manner under cover with the container lids on. Appendix A Maintenance and Inspection Forms Horizon View 2268-2284 Route 32 Montville CT 06353 Operation and Maintenance Plan Task Guide The table below is a list of the minimum inspection and maintenance activities the Pollution Prevention Team needs to conduct for the Stormwater Operations and Management Plan and who is responsible for the activity. The task Guide is provided to assist the Pollution Prevention Team Leader and ensure that the activities are being conducted as scheduled. Timing Task Responsible Party Weekly Inspect Lot/Land PPT Quarterly (March, June, September, December) Inspect Catch Basins PPT/Contractor Semi-Annually (March and September) Inspect Subsurface Systems Inlets, Outlets and overflow. Inspect sedimentation levels, remove as necessary PPT/Contractor Annually Pollution Prevention Team training Comprehensive Annual Stormwater Evaluation and Inspection Report Clean Catch Basins Inspect outlet control structure and power wash and jet vacuum PPT Leader PPT Leader PPT/Contractor PPT/Contractor April Spring clean-up PPT/Contractor Between November 14 and December 15 Fall clean-up PPT/Contractor Horizon View 2268-2284 Route 32 Montville CT 06353 Operations and Maintenance Plan Comprehensive Annual Evaluation and Inspection Report Once a year, the Pollution Prevention Team Leader must inspect and evaluate all aspects and provisions of the Operations and Maintenance Plan, complete the following report and keep a copy on file at the site. Inspector/Reviewers:________________________________________________________________ Date of Inspection/Review: __________________________________________________________ Note any changes to the Plan in the space below and in the appropriate section of the Plan. 1. Review the Pollution Prevention Team list and update if necessary. Does the Pollution Prevention Team list need updating: (circle one) Yes No 2. Review the Operations and Maintenance Plan (O&M Plan). Are there sections of the O&M Plan that need updating? (circle one) Yes No 3. Review Monthly and Weekly Checklists. Update these as necessary - Are there any updates needed to Spill and Leak History and/or the checklists? (circle one) Yes No 4. Review site drawings and update if necessary - Are there updates needed to any of the drawings? (circle one) Yes No Requested Changes (attach revisions) Horizon View 2268-2284 Route 32 Montville CT 06353 Operations and Maintenance Plan Annual Training Sign-off Sheet For each Operations and Maintenance Plan training session, the Team Leader should keep records of all attending Team Members using the signoff sheet below, as well as the training agenda, notes, etc. Training Date: _____________________________ Topic: Trainer: _____________________________________ Team Member Name Team Member Signature Horizon View 2268-2284 Route 32 Montville CT 06353 Operations & Maintenance Plan Weekly Task Checklist The site will be checked each week for trash and debris by a member of the Pollution Prevention Team. If any trash or debris is observed in the specified area, write “yes” in the 2nd column and note the problem and corrective measures taken in the appropriate space. Make a new copy of this checklist each week. Date: _________________________________ Checklist completed by: _______________________________________ GROUNDS AREA TO CHECK TASK DESCRIPTION OF PROBLEM CORRECTIVE MEASURES TAKEN Parking Lot & Roadways Pickup and Dispose of Litter Landscaped Areas Pickup and Dispose of Litter Compactor/Dumpster Areas Check for Leaking Liquid Pickup and Dispose of Litter Perimeter of Property Pickup and Dispose of Litter Horizon View 2268-2284 Route 32 Montville CT 06353 Operations & Maintenance Plan Quarterly Task Checklist (March, June, September, December) The following will be checked each month for sources of pollutants by a member of the Pollution Prevention Team. If the condition in the “check for” column is observed, note the problem and corrective measures taken in the appropriate space. Make a new copy of the checklist each month. Date: _________________________________ Checklist completed by: _______________________________________ BMP TASK DESCRIPTION OF PROBLEM (IF PRESENT) CORRECTIVE MEASURES TAKEN Catch Basins Inspect for Sediment, Trash, and Oil. Horizon View 2268-2284 Route 32 Montville CT 06353 Operations & Maintenance Plan Semi-Annual Task Checklist (March, September) The site will be checked semi-annually four sources of pollutants by a member of the Pollution Prevention Team. If the condition in the “check for” column is observed, note the problem and corrective measures taken in the appropriate space. Make a new copy of the checklist each month. Date: _________________________________ Checklist completed by: _______________________________________ BMP TASK DESCRIPTION OF PROBLEM (IF PRESENT) CORRECTIVE MEASURES TAKEN Subsurface Systems Inspect inlets, outlets, and overflow. Inspect sedimentation levels and remove as necessary. Horizon View 2268-2284 Route 32 Montville CT 06353 Operations & Maintenance Plan Annual Task Checklist The following will be check each year for sources of pollutant by a member of the Pollution Prevention Team. If a problem is observed, note the problem and corrective measures take in the appropriate space. Make a new copy of the checklist each year. Date: _________________________________ Checklist completed by: _______________________________________ BMP TASK DESCRIPTION OF PROBLEM (IF PRESENT) CORRECTIVE MEASURES TAKEN Pollution Prevention Team Training Pollution Prevention Team Training. Catch Basins Remove sediment and debris from sump and power wash. Outlet Control Structure Inspect, power wash and jet vacuum. Comprehensive Annual Stormwater Evaluation and Inspection Report Compile the comprehensive annual stormwater evaluation and inspection report and file for future reference. Horizon View 2268-2284 Route 32 Montville CT 06353 Long Term Pollution Prevention Plan Spill and Leak History (____ to _____) Date Spill Leak Location Description Response Procedures Measures to Prevent Reoccurrence Reporting Pollution Prevention Team Member (MM/DD/YY) (check one) (as indicated on Site Map) Type of Material Quantity Source, if known Reason Appendix B C-2 – Grading and Drainage Plan TVAN VAN4 STORIESWITH 57 UNITSFFE=152.50GMMM18" D18" DCB-5R=148.50I=146.00(DMH-3)12" D151.0515" D 151.25151.05APPROXIMATELY 9,770 SFOF 50' UPLAND REVIEWAREA BEING DISTURBEDTC=152.40BC=152.00152.50TC=153.70BC=153.20TW=154.50BW=149.50CB-1R=151.50I=148.50(DMH-1)12" DTC=153.75BC=153.25DMH-OS2 W/ DEEP SUMPR=152.00I=148.30(DMH-OS1)I=148.20(FES-1)TW=155.50BW=153.20TW=155.80BW=155.50TW=154.25BW=149.50TW=153.75BW=153.00DMH-OS1W/ DEEP SUMPR=153.10I=149.40(HW-1)I=149.30(DMH-OS2)TW=149.30BW=MATCH EX. (±144.0)TW=150.00BW=MATCH EX. (±144.0)TW=150.25BW=MATCH EX. (±144.0)TW=150.75BW=MATCH EX. (±144.0)TW=151.25BW=MATCH EX. (±144.0)TW=151.75BW=MATCH EX. (±144.0)TW=154.50BW=MATCH EX. (±144.0)TW=150.250BW=MATCH EX. (±144.0)152.50152.30155'12" DTW=150.50BW=MATCH EX. (±144.0)TW=150.50BW=150.0049'TC=152.00BC=151.50SUBSURFACEINFILTRATIONBASINBOTTOM STONE = 142.00BOTTOM PIPE = 142.50TOP PIPE = 149.50TOP STONE = 150.005 ROW OF 84"PERFORATED CMP PIPEON-SITE DETENTION BASINCB-2R=151.50I=148.10(DMH-1)DMH-1R=151.60I=148.00(CB-1)I=148.00(CB-2)I=147.90(CDS-1)CDS-1R=151.90I=147.60(DMH-1)I=147.60(SSIS-I1)CB-7R=151.25I=147.25()CB-3R=150.50I=147.50(DMH-2)CB-4R=150.75I=147.50(DMH-2)DMH-2R=151.50I=147.20(CB-3)I=147.20(CB-4)I=147.10(DMH-3)DMH-3R=150.20I=145.40(CB-5)I=146.40(DMH-2)I=145.30(CDS-2)CDS-2R=150.60I=144.60(DMH-3)I=144.60(CB-6)I=144.60(SSIS-I2)CB-6R=149.75I=145.00(CDS-2)OCS-1ORIFICE WITH TRASH RACK = 146.0WEIR = 150.00PIPE = 146.00151.00TC=151.70BC=151.20TC=151.70BC=151.20152.50152.40TC=152.40BC=151.90TC=152.40BC=151.90TC=151.50BC=151.00TC=151.50BC=151.00TC=151.95BC=151.45TC=151.75BC=151.25151.85152.05151.8018" DPERMANENTDISTURBEDAREA = ±636 SF153.40153.40SSIS-O1 LEVEL SPREADERWITH CURB EDGE(MIN. 55'L)OCS-OFFSITE20"X12" ORIFICE WITH TRASH RACK = 148.0WEIR = 150.00PIPE = 146.40TEMPORARY DISTURBEDAREA = ±432 SF151.204' HIGH CHAIN LINKFENCE WITH ACCESSGATESTW=149.00BW=MATCH EX. (±144.0)TW=151.75BW=MATCH EX. (±144.0)OFFSITEDETENTIONBASIN151.502: 1 1. 5 : 12:13:13:13:12:1OS-DMH3R=146.20I=142.40(OS-DMH2)I=142.30(OS-FES1)OS-DMH1R=147.80I=145.90(OCS-OFFSITE)I=145.80(OS-DMH2)SSI-OCS-1R=152.00I=146.00(SSI-OUT 1)ORIFICE=146.00WEIR=149.50I=146.00(FES-2)SSI-OCS-2R=152.00I=146.00(SSI-OUT 2)ORIFICE=146.00WEIR=149.50I=146.00(FES-3)CATCH BASIN/ SEDIMENTTRAP AND BEEHIVE FRAMEAND GRATE W/ 4 FT SUMPR=149.00I=149.5018" DFES-1I=148.00(DMH-OS2)FES-2I=146.00(SSI-OCS-1)RIP RAP APRON (SEE DWG. C-7)FES-3I=146.00(SSI-OCS-2)RIP RAP APRON (SEE DWG. C-7)OS-FES1I=142.00(OS-DMH3)SEE DWG. C-6 FOR LEVEL SPREADER DETAILS12" D12" D12" D12" D18" D12" D18 " D 18" DOS-DMH2R=151.25I=143.60(OS-DMH1)I=143.60(OCS-1)I=143.50(OS-DMH3)18" D153 1541 5 1 151151 150 149 151150150 151151150 153 152 151151 151 1511541521521531551531521531521 5 1 152 15 2 152 149148147146 152151.5151.515215215 1 15015215315 3 152150155154 15315 3 145 148151150146 154158160158156154152158156154 16216 0 16 2 156150 153153 152 153 153 150 150148 148 146 146147 148 149 150 151 153153 153153 153 150 148151 151 154155156157158159160161162163164165155 156 157 158 158 160 162148146143144143144 165155 156158160162164159157156155 148 30" D30" D18" D18" DRIP RAP APRON(SEE DWG. C-7TYP.)142152 150 152 150 148 Drawing name: G:\CT\Montville\Honeycomb Real Estate Partners\2268-2284 Route 32\Main\24029_C-2 Grading and Drainage Plan.dwg Sep 25, 2024 - 16:25pm 24029HORIZON VIEWMONTVILLE, CT20 AVON MEADOW LANEAVON, CT 06001DRAWING NUMBER:PROJECT NUMBER:Copyright © 2024 by R.J. O'Connell & Associates, Inc.RJO'CONNELL& ASSOCIATES, INC.CIVIL ENGINEERS, SURVEYORS & LAND PLANNERS80 MONTVALE AVENUE , SU ITE 201 STONEHAM, MA 02180PHONE: 781 .279.0180 RJOCONNELL.COM NO.DATEREVISIONDRAWING NAME:PREPARED FOR:DESIGNED BY:DRAWN BY:REVIEWED BY:DATE:PROJECT NAME:SCALE:PREPARED BY:SEAL:NO.DATEREVISION 1.09/25/2024SUBMITTED TO INLAND WETLANDS COMMISSIONC-2GRADING ANDDRAINAGE PLANMAP/RWSWJHBPD/RWS09/25/20241" = 30'0GRAPHIC SCALE IN FEET30153060PROPOSED CONTOUR ELEVATIONSPOT ELEVATIONDRAIN LINEDRAIN MANHOLELEGENDCATCH BASINDOUBLE CATCH BASINAREA DRAINDRAIN CLEAN OUTFLARED END SECTION33HEADWALLRIP RAP SPLASH PADROOF DRAINRDTRENCH DRAINBORINGTEST PITUNDISTURBED BUFFERRJOCNNOTES:1.SLOPES STEEPER THAN 3:1 REQUIRE EROSIONCONTROL MATTING FOR STABILIZATION.2.SEE DRAWING N-1 FOR GENERAL NOTES,EROSION CONTROL NOTES, DEMOLITION NOTES,GRADING & DRAINAGE NOTES, UTILITY NOTES,AND PARKING AND TRAFFIC CONTROL SIGNSCHEDULE.3.SEE DRAWING C-5 THROUGH C-10 FOR DETAILS. Appendix C CDS Stormwater Treatment Unit Operation and Maintenance Guidelines CDS Guide Operation, Design, Performance and Maintenance ENGINEERED SOLUTIONS 2 CDS® Using patented continuous deflective separation technology, the CDS system screens, separates and traps debris, sediment, and oil and grease from stormwater runoff. The indirect screening capability of the system allows for 100% removal of floatables and neutrally buoyant material without blinding. Flow and screening controls physically separate captured solids, and minimize the re-suspension and release of previously trapped pollutants. Inline units can treat up to 6 cfs, and internally bypass flows in excess of 50 cfs (1416 L/s). Available precast or cast-in- place, offline units can treat flows from 1 to 300 cfs (28.3 to 8495 L/s). The pollutant removal capacity of the CDS system has been proven in lab and field testing. Operation Overview Stormwater enters the diversion chamber where the diversion weir guides the flow into the unit’s separation chamber and pollutants are removed from the flow. All flows up to the system’s treatment design capacity enter the separation chamber and are treated. Swirl concentration and screen deflection force floatables and solids to the center of the separation chamber where 100% of floatables and neutrally buoyant debris larger than the screen apertures are trapped. Stormwater then moves through the separation screen, under the oil baffle and exits the system. The separation screen remains clog free due to continuous deflection. During the flow events exceeding the treatment design capacity, the diversion weir bypasses excessive flows around the separation chamber, so captured pollutants are retained in the separation cylinder. Design Basics There are three primary methods of sizing a CDS system. The Water Quality Flow Rate Method determines which model size provides the desired removal efficiency at a given flow rate for a defined particle size. The Rational Rainfall Method™ or the and Probabilistic Method is used when a specific removal efficiency of the net annual sediment load is required. Typically in the Unites States, CDS systems are designed to achieve an 80% annual solids load reduction based on lab generated performance curves for a gradation with an average particle size (d50) of 125 microns (μm). For some regulatory environments, CDS systems can also be designed to achieve an 80% annual solids load reduction based on an average particle size (d50) of 75 microns (μm) or 50 microns (μm). Water Quality Flow Rate Method In some cases, regulations require that a specific treatment rate, often referred to as the water quality design flow (WQQ), be treated. This WQQ represents the peak flow rate from either an event with a specific recurrence interval, e.g. the six-month storm, or a water quality depth, e.g. 1/2-inch (13 mm) of rainfall. The CDS is designed to treat all flows up to the WQQ. At influent rates higher than the WQQ, the diversion weir will direct most flow exceeding the WQQ around the separation chamber. This allows removal efficiency to remain relatively constant in the separation chamber and eliminates the risk of washout during bypass flows regardless of influent flow rates. Treatment flow rates are defined as the rate at which the CDS will remove a specific gradation of sediment at a specific removal efficiency. Therefore the treatment flow rate is variable, based on the gradation and removal efficiency specified by the design engineer. Rational Rainfall Method™ Differences in local climate, topography and scale make every site hydraulically unique. It is important to take these factors into consideration when estimating the long-term performance of any stormwater treatment system. The Rational Rainfall Method combines site-specific information with laboratory generated performance data, and local historical precipitation records to estimate removal efficiencies as accurately as possible. Short duration rain gauge records from across the United States and Canada were analyzed to determine the percent of the total annual rainfall that fell at a range of intensities. US stations’ depths were totaled every 15 minutes, or hourly, and recorded in 0.01-inch increments. Depths were recorded hourly with 1-mm resolution at Canadian stations. One trend was consistent at all sites; the vast majority of precipitation fell at low intensities and high intensity storms contributed relatively little to the total annual depth. These intensities, along with the total drainage area and runoff coefficient for each specific site, are translated into flow rates using the Rational Rainfall Method. Since most sites are relatively small and highly impervious, the Rational Rainfall Method is appropriate. Based on the runoff flow rates calculated for each intensity, operating rates within a proposed CDS system are GRATE INLET(CAST IRON HOOD FORCURB INLET OPENING) CREST OF BYPASS WEIR(ONE EASH SIDE) INLET(MULTIPLE PIPES POSSIBLE) OIL BAFFLE SUMP STORAGESEPARATION SLAB TREATMENT SCREEN OUTLET INLET FLUME SEPARATION CYLINDER CLEAN OUT(REQUIRED) DEFLECTION PAN, 3 SIDED(GRATE INLET DESIGN) 3 determined. Performance efficiency curve determined from full scale laboratory tests on defined sediment PSDs is applied to calculate solids removal efficiency. The relative removal efficiency at each operating rate is added to produce a net annual pollutant removal efficiency estimate. Probabilistic Rational Method The Probabilistic Rational Method is a sizing program Contech developed to estimate a net annual sediment load reduction for a particular CDS model based on site size, site runoff coefficient, regional rainfall intensity distribution, and anticipated pollutant characteristics. The Probabilistic Method is an extension of the Rational Method used to estimate peak discharge rates generated by storm events of varying statistical return frequencies (e.g. 2-year storm event). Under the Rational Method, an adjustment factor is used to adjust the runoff coefficient estimated for the 10-year event, correlating a known hydrologic parameter with the target storm event. The rainfall intensities vary depending on the return frequency of the storm event under consideration. In general, these two frequency dependent parameters (rainfall intensity and runoff coefficient) increase as the return frequency increases while the drainage area remains constant. These intensities, along with the total drainage area and runoff coefficient for each specific site, are translated into flow rates using the Rational Method. Since most sites are relatively small and highly impervious, the Rational Method is appropriate. Based on the runoff flow rates calculated for each intensity, operating rates within a proposed CDS are determined. Performance efficiency curve on defined sediment PSDs is applied to calculate solids removal efficiency. The relative removal efficiency at each operating rate is added to produce a net annual pollutant removal efficiency estimate. Treatment Flow Rate The inlet throat area is sized to ensure that the WQQ passes through the separation chamber at a water surface elevation equal to the crest of the diversion weir. The diversion weir bypasses excessive flows around the separation chamber, thus preventing re-suspension or re-entrainment of previously captured particles. Hydraulic Capacity The hydraulic capacity of a CDS system is determined by the length and height of the diversion weir and by the maximum allowable head in the system. Typical configurations allow hydraulic capacities of up to ten times the treatment flow rate. The crest of the diversion weir may be lowered and the inlet throat may be widened to increase the capacity of the system at a given water surface elevation. The unit is designed to meet project specific hydraulic requirements. Performance Full-Scale Laboratory Test Results A full-scale CDS system (Model CDS2020-5B) was tested at the facility of University of Florida, Gainesville, FL. This CDS unit was evaluated under controlled laboratory conditions of influent flow rate and addition of sediment. Two different gradations of silica sand material (UF Sediment & OK-110) were used in the CDS performance evaluation. The particle size distributions (PSDs) of the test materials were analyzed using standard method “Gradation ASTM D-422 “Standard Test Method for Particle-Size Analysis of Soils” by a certified laboratory. UF Sediment is a mixture of three different products produced by the U.S. Silica Company: “Sil-Co-Sil 106”, “#1 DRY” and “20/40 Oil Frac”. Particle size distribution analysis shows that the UF Sediment has a very fine gradation (d50 = 20 to 30 μm) covering a wide size range (Coefficient of Uniformity, C averaged at 10.6). In comparison with the hypothetical TSS gradation specified in the NJDEP (New Jersey Department of Environmental Protection) and NJCAT (New Jersey Corporation for Advanced Technology) protocol for lab testing, the UF Sediment covers a similar range of particle size but with a finer d50 (d50 for NJDEP is approximately 50 μm) (NJDEP, 2003). The OK-110 silica sand is a commercial product of U.S. Silica Sand. The particle size distribution analysis of this material, also included in Figure 1, shows that 99.9% of the OK-110 sand is finer than 250 microns, with a mean particle size (d50) of 106 microns. The PSDs for the test material are shown in Figure 1. Figure 1. Particle size distributions Tests were conducted to quantify the performance of a specific CDS unit (1.1 cfs (31.3-L/s) design capacity) at various flow rates, ranging from 1% up to 125% of the treatment design capacity of the unit, using the 2400 micron screen. All tests were conducted with controlled influent concentrations of approximately 200 mg/L. Effluent samples were taken at equal time intervals across the entire duration of each test run. These samples were then processed with a Dekaport Cone sample splitter to obtain representative sub-samples for Suspended Sediment Concentration (SSC) testing using ASTM D3977-97 “Standard Test Methods for Determining Sediment Concentration in Water Samples”, and particle size distribution analysis. Results and Modeling Based on the data from the University of Florida, a performance model was developed for the CDS system. A regression analysis was used to develop a fitting curve representative of the scattered data points at various design flow rates. This model, which demonstrated good agreement with the laboratory data, can then be used to predict CDS system performance with respect 4 to SSC removal for any particle size gradation, assuming the particles are inorganic sandy-silt. Figure 2 shows CDS predictive performance for two typical particle size gradations (NJCAT gradation and OK-110 sand) as a function of operating rate. Figure 2. CDS stormwater treatment predictive performance for various particle gradations as a function of operating rate. Many regulatory jurisdictions set a performance standard for hydrodynamic devices by stating that the devices shall be capable of achieving an 80% removal efficiency for particles having a mean particle size (d50) of 125 microns (e.g. Washington State Department of Ecology — WASDOE - 2008). The model can be used to calculate the expected performance of such a PSD (shown in Figure 3). The model indicates (Figure 4) that the CDS system with 2400 micron screen achieves approximately 80% removal at the design (100%) flow rate, for this particle size distribution (d50 = 125 μm). Figure 3. WASDOE PSD Figure 4. Modeled performance for WASDOE PSD. Maintenance The CDS system should be inspected at regular intervals and maintained when necessary to ensure optimum performance. The rate at which the system collects pollutants will depend more heavily on site activities than the size of the unit. For example, unstable soils or heavy winter sanding will cause the grit chamber to fill more quickly but regular sweeping of paved surfaces will slow accumulation. Inspection Inspection is the key to effective maintenance and is easily performed. Pollutant transport and deposition may vary from year to year and regular inspections will help ensure that the system is cleaned out at the appropriate time. At a minimum, inspections should be performed twice per year (e.g. spring and fall) however more frequent inspections may be necessary in climates where winter sanding operations may lead to rapid accumulations, or in equipment washdown areas. Installations should also be inspected more frequently where excessive amounts of trash are expected. The visual inspection should ascertain that the system components are in working order and that there are no blockages or obstructions in the inlet and separation screen. The inspection should also quantify the accumulation of hydrocarbons, trash, and sediment in the system. Measuring pollutant accumulation can be done with a calibrated dipstick, tape measure or other measuring instrument. If absorbent material is used for enhanced removal of hydrocarbons, the level of discoloration of the sorbent material should also be identified 5 during inspection. It is useful and often required as part of an operating permit to keep a record of each inspection. A simple form for doing so is provided. Access to the CDS unit is typically achieved through two manhole access covers. One opening allows for inspection and cleanout of the separation chamber (cylinder and screen) and isolated sump. The other allows for inspection and cleanout of sediment captured and retained outside the screen. For deep units, a single manhole access point would allows both sump cleanout and access outside the screen. The CDS system should be cleaned when the level of sediment has reached 75% of capacity in the isolated sump or when an appreciable level of hydrocarbons and trash has accumulated. If absorbent material is used, it should be replaced when significant discoloration has occurred. Performance will not be impacted until 100% of the sump capacity is exceeded however it is recommended that the system be cleaned prior to that for easier removal of sediment. The level of sediment is easily determined by measuring from finished grade down to the top of the sediment pile. To avoid underestimating the level of sediment in the chamber, the measuring device must be lowered to the top of the sediment pile carefully. Particles at the top of the pile typically offer less resistance to the end of the rod than consolidated particles toward the bottom of the pile. Once this measurement is recorded, it should be compared to the as-built drawing for the unit to determine weather the height of the sediment pile off the bottom of the sump floor exceeds 75% of the total height of isolated sump. Cleaning Cleaning of a CDS systems should be done during dry weather conditions when no flow is entering the system. The use of a vacuum truck is generally the most effective and convenient method of removing pollutants from the system. Simply remove the manhole covers and insert the vacuum hose into the sump. The system should be completely drained down and the sump fully evacuated of sediment. The area outside the screen should also be cleaned out if pollutant build-up exists in this area. In installations where the risk of petroleum spills is small, liquid contaminants may not accumulate as quickly as sediment. However, the system should be cleaned out immediately in the event of an oil or gasoline spill. Motor oil and other hydrocarbons that accumulate on a more routine basis should be removed when an appreciable layer has been captured. To remove these pollutants, it may be preferable to use absorbent pads since they are usually less expensive to dispose than the oil/water emulsion that may be created by vacuuming the oily layer. Trash and debris can be netted out to separate it from the other pollutants. The screen should be cleaned to ensure it is free of trash and debris. Manhole covers should be securely seated following cleaning activities to prevent leakage of runoff into the system from above and also to ensure that proper safety precautions have been followed. Confined space entry procedures need to be followed if physical access is required. Disposal of all material removed from the CDS system should be done in accordance with local regulations. In many jurisdictions, disposal of the sediments may be handled in the same manner as the disposal of sediments removed from catch basins or deep sump manholes. Check your local regulations for specific requirements on disposal. 6 CDS Diameter Distance from Water Surface Sediment Model to Top of Sediment Pile Storage Capacity ft m ft m yd3 m3 CDS2015-4 4 1.2 3.0 0.9 0.5 0.4 CDS2015 5 1.5 3.0 0.9 1.3 1.0 CDS2020 5 1.5 3.5 1.1 1.3 1.0 CDS2025 5 1.5 4.0 1.2 1.3 1.0 CDS3020 6 1.8 4.0 1.2 2.1 1.6 CDS3030 6 1.8 4.6 1.4 2.1 1.6 CDS3035 6 1.8 5.0 1.5 2.1 1.6 CDS4030 8 2.4 4.6 1.4 5.6 4.3 CDS4040 8 2.4 5.7 1.7 5.6 4.3 CDS4045 8 2.4 6.2 1.9 5.6 4.3 Table 1: CDS Maintenance Indicators and Sediment Storage Capacities Note: To avoid underestimating the volume of sediment in the chamber, carefully lower the measuring device to the top of the sediment pile. Finer silty particles at the top of the pile may be more difficult to feel with a measuring stick. These finer particles typically offer less resistance to the end of the rod than larger particles toward the bottom of the pile. 7 CDS Inspection & Maintenance Log CDS Model: Location: Water Floatable Describe Maintenance Date depth to Layer Maintenance Personnel Comments sediment1 Thickness2 Performed —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— —————————————————————————————————————————————————————————— 1. The water depth to sediment is determined by taking two measurements with a stadia rod: one measurement from the manhole opening to the top of the sediment pile and the other from the manhole opening to the water surface. If the difference between these measurements is less than the values listed in table 1 the system should be cleaned out. Note: to avoid underestimating the volume of sediment in the chamber, the measuring device must be carefully lowered to the top of the sediment pile. 2. For optimum performance, the system should be cleaned out when the floating hydrocarbon layer accumulates to an appreciable thickness. In the event of an oil spill, the system should be cleaned immediately.