Orange County NC Website
Browse       Search
134 <br /> future of this site. It is possible that additional soil evaluations will be required once lot <br /> layouts are considered and developed for this property so that septic system types and the <br /> location of a septic drainfield can be more fully and appropriately considered. <br /> Several areas (see map in Attachment 3) exhibited soil characteristics and soil depths <br /> (20" or greater)that are provisionally suitable for conventional or shallow conventional <br /> trench septic systems. These areas are approximately 80,418ft2, 1,613,285ft2, 96,442ft2, <br /> and 806,107ft2. <br /> Typical profile descriptions of the provisionally suitable soil for this property are in <br /> Attachment 4. Three distinct soil profiles were observed in the soil borings on the <br /> property: a deep red clay subsoil, a shallower reddish-yellow clay subsoil, and a very <br /> shallow reddish-yellow clay subsoil. <br /> The provisionally suitable soil borings had the following characteristics. No restrictive <br /> horizons were found in any provisionally soil borings within 24" of the soil surface. Soil <br /> texture was provisionally suitable and was estimated to be silt loam near the soil surface <br /> (A horizons) and clay loam to clay in the subsoil (B horizons). Soil structure was <br /> provisionally suitable and was estimated to be granular near the soil surface (A horizons) <br /> and subangular blocky in the subsoil (B horizons). Clay mineralogy was provisionally <br /> suitable with very friable to firm moist soil consistence and non-sticky to sticky and non- <br /> plastic to plastic wet soil consistence. Indications of saprolite were detected in some soil <br /> borings,but were not dominant in profiles. <br /> The major soil types on this property are Georgeville silt loam (map symbols GeB and <br /> GeQ, Herndon silt loam(map symbols HrB and HrQ, and Tarrus silt loam (map symbol <br /> Tal)). The Orange County Soil Survey indicates that moderate limitations exist for septic <br /> systems installed in these soil types (Attachment 5). <br /> The land area required for a conventional or shallow conventional septic system is <br /> calculated based on the size of the proposed home and the Long-Term Acceptance Rate <br /> (LTAR) of the soil. The LTAR range for the provisionally suitable soils on this property <br /> is 0.1 —0.4 GPD/ft2 based on the most restrictive soil texture in the subsoil. Table 1 <br /> below presents estimated conventional or shallow conventional septic system land area <br /> requirements for several home sizes and LTAR's on this property. The LTAR suggested <br /> by AWT for a majority of the provisionally suitable soil is 0.25 GPD/ft2,but the final <br /> LTAR for specific septic system types and septic drainfield locations will be set by the <br /> Orange County Health Department. The detailed computations are in Attachment 6. <br /> 2 <br />