1240815StormWaterManagementReportrcd 3 12 2026

Development Engineering, LLC 550 Colfax Road Wayne, NJ 07470 (973) 835-0340 The field test was performed Monday about 10:30 AM June 13, 2025 within the proposed area of the seepage pit, shown on the proposed Drainage Plan of the Site Plan, in accordance to the following steps: Step 1: Test Hole Excavated one hole in the proposed drywell area (desired soil percolation rate testing area). The hole measured about 4 feet wide by 7 feet long and about 10 feet deep. Since the proposed seepage pit area is about 8 feet x 10 feet wide, only one hole was dug in the center of the proposed seepage pit area. A soil sample was also collected from the bottom of the pit for libratory analysis. Step 2: Soil Saturation Attempted to completely fill the test hole with water, and waited several hours for the water to fill the hole so it subsequently drains into the soil but the water was draining very rapidly. Step 3: Refill Test Hole Ensured the water had drained completely, and refilled the hole with water up to within 10" inches of its bottom. Step 4: Measure Initial Water Level Laid a wood board across the top of the test hole as the measuring baseline. Then, inserted a tape measure to the test hole bottom and measured the distance from the measuring baseline (2x10 board) to the water level. Step 5: Measure Final Water Level Change Returned to the test hole, inserted a tape measure to the test hole's bottom, and after 7.5 minutes measured the new distance from the board to the water level. Step 6: Repeat Measurements Measured the distance between the water level and the board every 7.5 minutes three additional times. After taking four measurements, determined how much the water level had dropped between each measurement. The amount of change per hour is the soil's percolation rate. For the proposed seepage pit area, the water level dropped at the rate of more than 5.8 inches per hour. The water table was not encountered during the test hole excavation about 10.0 feet below the grade. 2 7