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

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 3 of 4 Bedrock The top of bedrock was encountered below the natural soils ranging from approximately 1 ft to 9 ft below surface grade in test pits TP-1, TP-7, TP-14, TP-15, TP-16, TP-18, TP-19, TP-20 and TP- 21. The remaining test pits were terminated prior to reaching the top of bedrock. Signs of Seasonal High Water Table The signs of Seasonal High Water Table (SHWT) as identified in the New Jersey Stormwater Best Practices Manual include visual observation of groundwater seepage and soil mottling. The location, depth and elevation of observed soil mottling and/or water seepage encountered in the profile test pits are summarized below. The determination of the SHWT elevation is provided in Table 1 – Summary of Profile Test Pits and Infiltration Testing Results. Soil Mottling Approximate Depth of Approximate Elevation Test Pit Observed Mottling of Observed Mottling TP-8 7 ft el 537 TP-10 2 ft el 535 TP-20 2 ft el 564.5 TP-21 6 ft el 533.5 Water Seepage Approximate Depth of Approximate Elevation Test Pit Observed Water of Observed Water Seepage Seepage TP-2 8 ft el 529 TP-8 6 ft el 538 TP-10 7.7 ft el 529.3 TP-13 3 ft el 548 TP-21 1 ft el

7.7 ft el 529.3 TP-13 3 ft el 548 TP-21 1 ft el 538.5 PERMEABILITY TESTING RESULTS AND HSG RECLASSIFICATION The hydraulic conductivity rates ranging from approximately 0.000417 to 0.0484 inches per hour were determined in the 20 samples taken as part of this subsurface investigation. = = =