complete drainage report rev 9

NJ DEP 2-hr WQ Rainfall=1.25" Combined FT (8-22-24) Prepared by Contech Engineered Solutions HydroCAD® 10.20-3f s/n 00447 © 2023 HydroCAD Software Solutions LLC Printed 8/26/2024 Page 48 Summary for Pond 21FT: 6x4 FT Inflow Area = Inflow = Outflow = Primary = 2,320 sf, 88.36% Impervious, Inflow Depth = 0.93" for WQ event 0.15 cfs @ 1.08 hrs, Volume= 181 cf 0.15 cfs @ 1.08 hrs, Volume= 181 cf, Atten= 0%, Lag= 0.0 min 0.15 cfs @ 1.08 hrs, Volume= 181 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 0.01' @ 1.08 hrs Surf.Area= 24 sf Storage= 0 cf Plug-Flow detention time= 0.0 min calculated for 181 cf (100% of inflow) Center-of-Mass det. time= 0.0 min ( 66.2 - 66.2 ) Volume #1 Device #1 Invert 0.00' Routing Primary Avail.Storage 18 cf Invert 0.00' Storage Description 6.00'W x 4.00'L x 0.75'H Prismatoid Outlet Devices 300.000 in/hr Exfiltration over Surface area Primary OutFlow Max=0.17 cfs @ 1.08 hrs HW=0.01' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.17 cfs @ 0.01 fps) Pond 21FT: 6x4 FT Hydrograph 0.16 0.15 0.14 0.13 0.12 Flow (cfs) 0.11 0.15 cfs 0.15 cfs Inflow Primary Inflow Area=2,320 sf Peak Elev=0.01' Storage=0 cf 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)

NJ DEP 2-hr WQ Rainfall=1.25" Combined FT (8-22-24) Prepared by Contech Engineered Solutions HydroCAD® 10.20-3f s/n 00447 © 2023 HydroCAD Software Solutions LLC Printed 8/26/2024 Page 49 Summary for Pond 22FT: 8x6 FT Inflow Area = Inflow = Outflow = Primary = 9,140 sf, 42.59% Impervious, Inflow Depth = 0.54" for WQ event 0.36 cfs @ 1.08 hrs, Volume= 411 cf 0.33 cfs @ 1.06 hrs, Volume= 405 cf, Atten= 7%, Lag= 0.0 min 0.33 cfs @ 1.06 hrs, Volume= 405 cf Routing by Stor-Ind method, Time Span= 0.00-72.00 hrs, dt= 0.01 hrs / 2 Peak Elev= 0.05' @ 1.09 hrs Surf.Area= 48 sf Storage= 3 cf Plug-Flow detention time= 0.8 min calculated for 405 cf (98% of inflow) Center-of-Mass det. time= 0.0 min ( 68.3 - 68.2 ) Volume #1 Device #1 Invert 0.00' Routing Primary Avail.Storage 36 cf Invert 0.00' Storage Description 8.00'W x 6.00'L x 0.75'H Prismatoid Outlet Devices 300.000 in/hr Exfiltration over Surface area Primary OutFlow Max=0.33 cfs @ 1.06 hrs HW=0.01' (Free Discharge) 1=Exfiltration (Exfiltration Controls 0.33 cfs @ 0.01 fps) Pond 22FT: 8x6 FT Hydrograph 0.4 0.36 cfs 0.38 0.36 0.33 cfs 0.34 0.32 Flow (cfs) 0.3 0.28 0.26 Inflow Primary Inflow Area=9,140 sf Peak Elev=0.05' Storage=3 cf 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 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours)

ie) State of New Jersey DEPARTMENT OF ENVIRONMENTAL PROTECTION DIVISION OF WATER QUALITY Bureau of Stormwater Permitting 401 East State Street JI PHILIP D. MURPHY : SHAWN M. LATOURETTE Governor P.O. Box 420 Mail Code 401-02B Acting Commissioner Trenton, NJ 08625-0420 SHEILA Y. OLIVER Tel. (609) 633-7021 * Fax (609) 777-0432 www.nj.gov/dep/dwa/bnpc_home.htm Lt. Governor February 12, 2021 Derek M. Berg Director — Stormwater Regulatory Management - East Contech Engineered Solutions LLC 71 US Route 1, Suite F Scarborough, ME 04074 Re: MTD Lab Certification Filterra® HC Bioretention System Off-line Installation Approved TSS Removal Rate 80% Dear Mr. Berg: The Stormwater Management rules under N.J.A.C. 7:8-5.5(b) and 5.7(c) allow the use of manufactured treatment devices (MTDs) for compliance with the design and performance standards at N.J.A.C. 7:8-5 if the pollutant removal rates have been verified by the New Jersey Corporation for Advanced Technology (NJCAT) and have been certified by the New Jersey Department of Environmental Protection (NJDEP). Contech Engineered Solutions LLC has requested a Laboratory Certification for the Filterra® HC Bioretention System (Filterra® HC.) The project falls under the “Procedure for Obtaining Verification of a Stormwater Manufactured Treatment Device from New Jersey Corporation for Advance Technology” dated January 25, 2013. The applicable protocol is the “New Jersey Department of Environmental Protection Laboratory Protocol to Assess Total Suspended Solids Removal by a Filtration Manufactured Treatment Device” dated January 25, 2013. NIJCAT verification documents submitted to the NJDEP indicate that the requirements of the aforementioned protocol have been met or exceeded. The NJCAT letter also included a recommended certification TSS removal rate and the required maintenance plan. The NJCAT Verification Report with the Verification Appendix (dated January 2021) for this device is published online at http://www.njcat.org/uploads/newDocs/NJCATFilterraTechnology VerificationReportFinal._.pdf. New Jersey is an Equal Opportunity Employer. Printed on Recycled Paper and Recyclable.

The NJDEP certifies the use of the Filterra® HC stormwater treatment unit by Contech Engineered Solutions LLC at a TSS removal rate of 80% when designed, operated, and maintained in accordance with the information provided in the Verification Appendix and the following conditions: 1. The maximum treatment flow rate (MTFR) for the manufactured treatment device (MTD) is calculated using the New Jersey Water Quality Design Storm (1.25 inches in 2 hrs) in N.J.A.C. 7:8-5.5. The MTER is calculated based on a verified loading rate of 3.12 gpm/ft” of effective filtration treatment area. The Filterra® HC stormwater treatment unit shall be installed using the same configuration reviewed by NJCAT, and sized in accordance with the criteria specified in item 7 below. This device cannot be used in series with another MTD or a media filter (such as a sand filter) to achieve an enhanced removal rate for total suspended solids (TSS) removal under N.J.A.C. 7:8-5.5. Additional design criteria for MTDs can be found in the New Jersey Stormwater Best Management Practices (NJ Stormwater BMP) Manual, which can be found online at www.njstormwater.org. The maintenance plan for a site using this device shall incorporate, at a minimum, the maintenance requirements for the Filterra® HC. A copy of the maintenance plan is attached to this certification. However, it is recommended to review the maintenance website at https://www.conteches.com/Portals/0/Documents/Maintenance%20Guides/Filterra%20H C%200M%20Packet.pdf for any changes to the maintenance requirements. For an MTD to be considered “green infrastructure” (GI) in accordance with the March 2, 2020 amendments to the Stormwater Management rules at N.J.A.C. 7:8, the MTD must meet the GI definition noted at amended N.J.A.C. 7:8-1.2. Specifically, the MTD shall (1) treat stormwater runoff through infiltration into subsoil; and/or (2) treat stormwater runoff through filtration by vegetation or soil; or (3) store stormwater runoff for reuse. The Filterra® HC filters stormwater runoff through an engineered biofiltration soil media and, thus, meets the definition of GI. Filterra® HC can be configured with or without a precast vault. Installations that will not include a precast vault will additionally need to comply the NJDEP Stormwater BMP Manual conditions regarding separation from the seasonal high water table and, if

t vault. Installations that will not include a precast vault will additionally need to comply the NJDEP Stormwater BMP Manual conditions regarding separation from the seasonal high water table and, if infiltration is proposed as an outlet, minimum vertical saturated hydraulic conductivity of the subsoil. Installations without a precast vault that do not rely on infiltration are required to maintain at least a one-foot separation from the seasonal high water table measured from the lowest point of the system. Installations without a precast vault that utilize infiltration are required to have the most hydraulically restrictive soil layer below the MTD meet the minimum tested vertical saturated hydraulic conductivity of one inch per hour and have at least two feet of separation from the seasonal high water table measured from the lowest point of the system.

7. Sizing Requirement: The example below demonstrates the sizing procedure for the Filterra® HC: Example: A 0.25-acre impervious site is to be treated to 80% TSS removal using the Filterra® HC. The impervious site runoff (Q) based on the New Jersey Water Quality Design Storm was determined to be 0.79 cfs. The selection of the appropriate model of Filterra® HC is based upon both the maximum inflow drainage area and the MTFR. It is necessary to calculate the required model using both methods and to use the largest model determined by the two methods. Inflow Drainage Area Evaluation: The drainage area to the Filterra® HC in this example is 0.25 acres. Included in Table 1 below, all of the Filterra® HC models are designed with a maximum allowable drainage area greater than 0.25 acres. Specifically, the Filterra® HC with a 4’x4’ media bay and a maximum allowable drainage area of 0.40 acres would be the smallest model able to treat runoff without exceeding the maximum allowable drainage area. Maximum Treatment Flow Rate (MTFR) Evaluation: The site runoff (Q) was based on the following: time of concentration = 10 minutes i= 3.2 in/hr (page 5-8, Fig. 5-3 of the NJ Stormwater BMP Manual) c = 0.99 (runoff coefficient for impervious) Q=ciA = 0.99 x 3.2 x 0.25 = 0.79 cfs Given the site runoff is 0.79 cfs and based on the MTFR’s listed in Table 1 below, the Filterra®” HC with a 16’x8’ media bay and an MTFR of 0.889 cfs would be the smallest model that could be used to treat the impervious area without exceeding the MTFR. If using more than one unit for treating runoff, the units should be configured such that the flowrate to each unit does not exceed the design MTFR for each unit and ensuring the entire 0.25 acre area is treated. The MTFR evaluation results will be used since that method results in the highest minimum configuration determined by the two methods.

The sizing table corresponding to the available system models is noted below: Table 1. Filterra® HC MTFRs and Maximum Allowable Drainage Areas Available Fiterra® Media Bay Sizes | Effective Filtration | Treatment Flow Rate | Maximum Allowable (Feet) Treatment Area (ft) (c6) Drainage Area (ac) axd 16 oul 040 4x6 or 6x4 4 0167 0.60 | 451783 0r783x45 (Nominal 4x8814) 3524 0.45 099 z 6x6 %6 0280 091 5 : 4 6x8 or 8x6 8 0333 121 i da 6x10 oF 10x6 0 o4l7 1sI ts a 6x2 or 1246 n 0.500 181 ge TaL3 or 7 41 0632 29 2? a Laxg 112 078 22 E Lx 128 0.889 32 E 1x8 4 1.000 36 2x8 16 ul 403 od 16 1m 48 44 16 onl 040 4.5x5.83 (Nominal 4x6) 264 0.182 0.6 6x4 4 0.167 0.60 gs 23 6x6 % 0250 091 2> 4 Kt x m4 aE 6x8 8 0333 121 5 qe 6x10 or 10x6 ry o4i7 151 ff 1x10 0 0.486 1%6 axl05 4 0583 2 sxl25 100 0.64 232 Custom and/or Filtera Bioscape Media Area in ft” [0.00694 * (Media Area in ft)} 0.0252 * (Media Area in ft?)

Be advised a detailed maintenance plan is mandatory for any project with a Stormwater BMP subject to the Stormwater Management rules, N.J.A.C. 7:8. The plan must include all of the items identified in the Stormwater Management rules, N.J.A.C. 7:8-5.8. Such items include, but are not limited to, the list of inspection and maintenance equipment and tools, specific corrective and preventative maintenance tasks, indication of problems in the system, and training of maintenance personnel. Additional information can be found in Chapter 8: Maintenance and Retrofit of Stormwater Management Measures. If you have any questions regarding the above information, please contact me at (609) 633-7021. Sincerely, - l f fl A ’ UY Ww Malek W ahs Gabriel Mahon, Chief Bureau of Stormwater Permitting Attachment: Maintenance Plan ce: Chron File Richard Magee, NJCAT Vince Mazzei, NJDEP — Water & Land Management Nancy Kempel, NJDEP- BSTP Keith Stampfel, NIDEP — DLRP Dennis Contois, NJDEP — DLRP

Filterra HC Owner’s Manual rilterra Bioretention Systems S% ° a ENGINEERED SOLUTIONS

2) filterra Bioretention Systems Table of Contents Warranty Overview Routine Maintenance Guidelines. Maintenance Visit Procedure. Appendix 1 — Activation Checklist Appendix 2 — Planting Requirements for Filterra HC Systems.......... 13 s% ° «sNTECH ENGINEERED SOLUTIONS www.ContechES.com/filterra | 800-338-1122