2026 02 12 Crestmont CC and Eagle Rock Ave Stormwater Management Report

59 NRCS Runoff PR-2C-D Open Space D 0.348 65 341 ---- 60 NRCS Runoff PR-2C-D Impervious 0.837 65 1,021 ---- 61 Junction PR-2C-D 1.186 65 1,362 59, 60 63 NRCS Runoff PR-2C-U Open Space C 0.081 79 182 ---- 64 NRCS Runoff PR-2C-U Woods C 0.034 87 92.0 ---- 65 NRCS Runoff PR-2C-U Gravel C 0.125 65 122 ---- 66 NRCS Runoff PR-2C-U Impervious 1.386 65 1,690 ---- 67 Junction PR-2C-U 1.517 65 2,086 63, 64, 65, 66 70 Junction POA-2 2.799 65 4,865 46, 57, 61, 67

= = = = = = SMALL-SCALE BIORETENTION BASIN DESIGN SUMMARY

CRESTMONT COUNTRY CLUB EAGLE ROCK AVE IMPROVEMENTS LANGAN PROJECT #101049802 TOWNSHIP OF WEST ORANGE, NJ SMALL-SCALE BIORETENTION BASIN DESIGN SUMMARY TABLE CRESTMONT COUNTRY CLUB & EAGLE ROCK AVE IMPROVEMENTS LANGAN PROJECT #101049802 BOTTOM OF TOTAL SOIL MEDIA OCS FIRST DESIGN 100-YR EMERGENCY SURFACE INFLOW UNDERDRAIN BOTTOM OF TOP OF CONTRIBUTING DESIGN BIORETENTION BASIN ORIFICE WATER SURFACE SPILLWAY AREA OF DRAINAGE STONE BEDDING STORAGE EL. BERM EL. WATERSHED PERCOLATION OPENING EL. EL. CREST EL. BASIN (AC) AREA (AC) EL. (AC) RATE (IN/HR) SSBB-1 530.50 534.00 534.60 536.73 537.75 539.00 1.56 0.15 1.41 1.50 SSBB-2 533.50 537.00 537.40 539.63 540.67 542.00 2.26 0.35

1.41 1.50 SSBB-2 533.50 537.00 537.40 539.63 540.67 542.00 2.26 0.35 1.91 1.50 NOTES: \\langan.com\data\PAR\data8\101049801\Project Data\_Discipline\Site Civil\Stormwater\Eagle Rock Bioretention Basin Summary

= = = = = = POROUS ASPHALT PAVEMENT DESIGN CALCULATIONS

POROUS PAVEMENT SYSTEM DESIGN CALCULATIONS Design Notes and Standards: 1. The NJDEP water quality design storm event is 1.25 inches over a period of 2 hours. 2. The maximum ratio of additional inflow drainage area to surface area of the porous pavement system is 3:1. 3. The storage bed of the porous pavement system must drain within 72 hours. 4. The void space of the stone storage bed is assumed to be 40%. 5. The seasonal high water table or bedrock must be a minimum of 1 foot below the bottom of the storage bed. 6. The proposed porous pavement system has been designed to allow for additional storage capacity for quanitity control measures for the larger storm events. An outlet control structure has been designed which will control the rate of discharge; the underdrain system has been provided to promote complete drainage of the system. POROUS PAVEMENT BED DEPTH STORAGE WQ STORM RUNOFF MIN. UNDERDRAIN PIPE DIA. MIN. UNDERDRAIN UNDERDRAIN BED AREA (SF) SYSTEM AREA (IN) VOLUME (CF) VOLUME (CF) (IN) PIPE SLOPE (FT/FT) CAPACITY (CFS) PAPS-1 6,586 36 7,903 1,511 4 0.005 0.15 Pavement Area Cover Type Soil Type Area (ac) Area (sf) CN S Q Runoff (in) Runoff Volume (CF) Open Space/Grass C 0.01 305 74 3.51 0.07 2 PAPS-1 Open Space/Grass D 0.03 1,485 80 2.50 0.17 21 Impervious - 0.40 17,262 98 0.20 1.03 1,488 TOTAL: 0.44 19,052

0.20 1.03 1,488 TOTAL: 0.44 19,052 1,511 ADDITIONAL INFLOW DRAINAGE AREA RATIO (X:1) 1.89 ADDITIONAL INFLOW IMPERVIOUS AREA RATIO (X:1) 1.62

= = = = = = APPENDIX F GEOTECHNICAL INVESTIGATION INFORMATION

Memorandum 300 Kimball Drive Parsippany, NJ 07054 T: 973.560.4900 F: 973.560.4901 To: Mark Hoffman/ Garden Homes From: Adam Yoda / Langan Bhumi Peer / Langan Info: Michael Vitello / Langan Date: 25 August 2025 Revised: 12 February 2026 Re: Stormwater Management Field Testing Results Eagle Rock Ave & Oval Road Improvements 750 Eagle Rock Avenue West Orange, New Jersey Langan Project No.: 101049802 This memorandum presents the results of the field investigation and associated tube permeameter testing performed by Langan Engineering and Environmental Services, LLC (Langan) for the proposed Eagle Rock Ave and Oval Road road widening project site in West Orange, New Jersey. The elevations given in this memorandum are referenced to the surface contours provided in the drawing entitled “Right of Way & Partial Site Survey” dated 11 February 2026, prepared by Langan. The proposed stormwater management system information provided in this memorandum is referenced to the drawings entitled “Partial Grading Plan” dated 12 February, 2026, prepared by Langan. PROJECT DESCRIPTION The site is located immediately south of Eagle Rock Avenue between Laurel Avenue and Wakeman Street in West Orange, New Jersey. The site is currently occupied by wooded areas, landscape areas and paved areas associated with the Crestmont Country Club (CCC). Surface grades vary across the proposed project site, typically sloping downward from elevation (el) 570 at the existing parking area to el 530 at Eagle Rock Avenue. The proposed road widening project will also include the construction of site features at the CCC property. The proposed new site features will include additional parking lots, new roadways, site retaining walls and two (2) stormwater bioretention basins. Our field investigation was performed to support the design of the stormwater management systems for the project. FIELD INVESTIGATIONS The stormwater field investigation included excavating exploratory profile test pits under full-time observation of Langan and performing laboratory tube permeameter tests. The profile test pit locations and proposed target elevations were identified by Langan during the field investigation.

Stormwater Management Field Testing Results MEMO Eagle Rock Ave and Oval Road Improvements 750 Eagle Rock Avenue, West Orange, New Jersey Langan Project No. - 101049802 25 August 2025 - Page 2 of 4 The locations of all test pits are shown on Figures 1A and 1B. Logs of the profile test pits and test pit photographs are provided in Appendix A and B, respectively. Profile Test Pits A total of twenty-one (21) exploratory profile test pits were excavated by Frank Semeraro Construction, Inc. throughout the project site. Profile test pits identified as TP-1 through TP-10 were excavated between 25 and 26 April 2024 using a CAT 306 excavator. Profile test pits identified as TP-11 through TP-21 were excavated between 14 and 15 April 2025 using a Hitachi Excavator 7X85. The profile test pits extended between 1.75 ft and 12 ft below existing surface grade. Upon completion, the profile test pits were backfilled with excavated materials and compacted with the excavator bucket. Laboratory Tube Permeameter Tests A total of twenty (20) tube permeameter samples were collected and tested during the 2024 and 2025 subsurface investigation. These samples were collected within the upper 40 inches of the existing surface grade in compliance with the latest version of the New Jersey Stormwater Best Management Practices Manual, Chapter 12, Subsection A2: Tube Permeameter Test. The tube permeameter samples, identified using the corresponding profile test pit identification number, were collected in close proximity to the respective profile test pit location. The samples were tested to determine the soil hydraulic conductivity, which was used to determine the Hydrologic Soil Group (HSG). SUBSURFACE CONDITIONS The generalized subsurface conditions consist of surficial materials over sand and silt material underlain by bedrock. Significant amounts of gravel and cobbles were observed to be intermixed in the overburden soil layer. A generalized description of the subsurface conditions is provided below. Surficial Material Surficial materials consisted of grass and topsoil. An approximately 0.5-ft to 3-ft-thick