The subject property is located almost at the end of Sams Road. The site contains one building with a gravel driveway providing access to Sams Road, a woodland or heavy vegetation area with some dirt roads crossing the property. The site exhibits environmental constraint in the southernmost corner of the property. Runoff from the site flows to the rear site of the lot (POA).
Based on the NRCS Soil Survey the site is mapped as Downer Loamy Sand, Mullica Sandy Loam and Sassafras sandy loam (HSG A). Preliminary Soil evaluations were conducted on the site including test pits and field percolations tests. The site had a tested permeability rate ranging from 12.2 and 14.5 inches/hr which results in a design permeability rate ranging from 6.1 and 7.25 in/hr. Groundwater table or signs of SHWT were encountered at 7.1 feet below grade (el. 89.0). Test pit logs and infiltration test results are included in the appendix. Additional soil testing shall be undertaken as part of resolution compliance.
The applicant proposes to construct a Major Subdivision, along with associated site improvements such as new roadway, landscape, lighting, and stormwater management.
The stormwater management system consists of 2 surface infiltration basins and individual subsurface basins for each dwelling. Surface runoff from the site is partially directed to the 2 surface basins for water quality treatment and attenuation. Runoff from remaining woodland area of the property is not captured in the proposed stormwater facilities. Each proposed roof runoff is directed to the individual lot subsurface basin. An outlet control structure is proposed in each surface basin which will direct runoff in excess of the water quality storm via a 15" (Surface #1) and 6" (Surface #2) outlet pipe to convey excess runoff beyond required reductions to a swale near the property limit.
The system was routed using HydroCAD software for the 2, 10, 25, and 100 year events. Calculations are included in the appendix.