Orange County NC Website
Browse       Search
194 <br />Five categories of soil and landscape characteristics are evaluated to determine soil suitability for <br />domestic sewage treatment and disposal systems and include: topography and landscape <br />position, soil morphological characteristics, soil wetness conditions, soil depth, and restrictive <br />horizons. The soil and landscape characteristics found in a particular location dictate the type(s) <br />of domestic sewage treatment and disposal system that can be used on a parcel of land. The <br />detailed rules can be found in Section .1900 — Sewage Treatment and Disposal Systems as <br />Amended by the Orange County Board of Health, but a general review of the five categories and <br />other relevant rules can be found in the sections below. <br />.1940 TOPOGRAPHY AND LANDSCAPE POSITION <br />Uniform slopes less than 15 percent are considered suitable, uniform slopes between 15 and 30 <br />percent are considered provisionally suitable, and slopes greater than 30 percent are considered <br />unsuitable for domestic sewage treatment and disposal systems. Complex slope patterns and <br />slopes dissected by gullies and ravines are considered unsuitable for domestic sewage treatment <br />and disposal systems. Depressions and wetlands are also considered unsuitable for domestic <br />sewage treatment and disposal systems. <br />.1941 SOIL MORPHOLOGICAL CHARACTERISTICS <br />Sandy and coarse loamy textured soils (sand, loamy sand, sandy loam, and loam) are considered <br />suitable for domestic sewage treatment and disposal systems. Fine loamy and clayey textured <br />soils (silt, silt loam, sandy clay loam, clay loam, silty clay loam, sandy clay, silty clay, and clay) <br />are considered provisionally suitable for domestic sewage treatment and disposal systems. <br />Crumb, granular, and single - grained soil structures are considered suitable for domestic sewage <br />treatment and disposal systems. Blocky soil structures are considered provisionally suitable for <br />domestic sewage treatment and disposal systems. Platy, prismatic, and massive soil structures <br />are considered unsuitable for domestic sewage treatment and disposal systems. <br />Slightly expansive clay mineralogy is considered suitable for domestic sewage treatment and <br />disposal systems. Slightly expansive clay minerals exhibit loose, very friable, friable, or firm <br />moist soil consistence. Expansive clay mineralogy is considered unsuitable for domestic sewage <br />treatment and disposal systems. Expansive clay minerals exhibit very firm or extremely firm <br />moist soil consistence. Organic soils are considered unsuitable for domestic sewage treatment <br />and disposal systems. <br />.1942 SOIL WETNESS CONDITIONS <br />Soil wetness conditions are caused by seasonal high water table, perched water table, tidal water, <br />seasonally saturated soils, or lateral water movement. Soil wetness conditions are indicated by <br />soil colors, either in mottles or mass, with a chroma of 2 or less according to the Munsell color <br />charts. Soil wetness conditions detected 48 inches in depth or deeper are considered suitable for <br />domestic sewage treatment and disposal systems. Soil wetness conditions detected between 36 <br />to 48 inches in depth are considered provisionally suitable for domestic sewage treatment and <br />disposal systems. Soil wetness conditions detected 36 inches in depth or shallower are <br />considered unsuitable for domestic sewage treatment and disposal systems. <br />