PB 22 10 Altera 769 LLC Filed Application with Exhibits Final Site Plan Phase 2

Based upon the Essex County Soil Survey the soil types native to the site include: HYDRAULIC SOIL TYPE SOIL TYPE NAME SOIL GROUP* BogB Boonton Loam, 3 to 8 percent slopes C Boonton Loam, 0 to 8 percent slopes, BogBc C extremely stony Boonton – Urban Land, Boonton BouB C Substratum Complex, 0 to 8 percent slopes Urban Land, Boonton Substratum, 0 to 8 URBONB C percent slopes *A field investigation of the existing on-site soils was performed by Dynamic Earth, LLC to evaluate subsoil conditions to estimate depth to the seasonal high groundwater levels and permeability rates. Based on laboratory testing, permeability rates were less than 0.06 inches per hour, which is consistent with a hydrologic soil group (HSG) D. For the purposes of the design, the site has been modeled as HSG D in the Runoff Curve Number calculations. A copy of the Runoff Curve Number calculations as well as the Stormwater Basin Area Investigation Report prepared by Dynamic Earth, LLC are provided within the Appendix of this report. The existing site conditions have been evaluated using the following drainage sub-watershed areas as depicted on the Existing Drainage Area Map included within the Appendix within this report: Existing DA-1: This area consists of the wooded area at the northern most part of the site. Stormwater runoff generated by this area sheet flows overland in a westerly direction, where it is collected by an existing stormwater pipe (POI-1) along the western property line. A time of concertation of 18.5 minutes has been calculated and utilized for this drainage area. Existing DA-2: This area consists of the northern portion of

(POI-1) along the western property line. A time of concertation of 18.5 minutes has been calculated and utilized for this drainage area. Existing DA-2: This area consists of the northern portion of the existing rear parking area and a portion of the wooded areas. Stormwater runoff generated by this area sheet flows overland to the west where it is collected by a series of existing inlets where is it ultimately conveyed to the existing stormwater management structure (POI-2). A time of concentration of 16.1 minutes has been calculated and utilized for this drainage area. Existing DA-3: This area consists of the remainder of the subject site which includes the existing office building, remaining parking areas and open space (lawn) areas. Stormwater runoff generated by this area sheet flows overland in a southerly direction where it is collected by a series of existing inlets. Ultimately, stormwater runoff is conveyed to the existing stormwater conveyance system within Northfield Avenue (CR 508) (POI-3). A minimum time of concentration of six (6) minutes has been utilized for this drainage area. Altera 769, LLC 4 Revised August 2022 DECPC #2530-99-006