Laserfiche WebLink
Soil Suitability J Nitrate Loading Study Irerracon <br /> Whitlow Property ■ Stockton, CA <br /> November 20, 2019 r Terracon Project No. NA197078 <br /> The Hantzsche and Finnemgre approach is "...a conservative (worst case)first approximation of <br /> groundwater nitrate-nitrogen concentration resulting from the combined effect of on-site sewage <br /> disposal systems and precipitation. This {the equation and approach) is for estimation of long- <br /> term effect(i.e., over years) on groundwater quality, and is not intended for prediction of seasonal <br /> changes" (Hantzsche and Finnemore, 1992). <br /> The method takes into account the development area. soil denitrification factor, rainfall Volume, <br /> rainfall nitrate concentration, waste effluent quantity, and waste effluent nitrate concentration. The <br /> formula, assumptions and calculations used for the analysis are shown in Appendix F. The units <br /> of nitrate used in the mass balance equation are nitrate-N, whose maximum drinking water <br /> contaminant level (MCL) is 10 mgfL. <br /> 2.1 Chemical and Physical Properties of Soil <br /> 2.1.1 Chemical and Physical Soil Properties <br /> Terracon reviewed the USDA NRCS Web Sail Survey and USDA Soil Survey of San Joaquin <br /> County (1992) for information regarding Hoilenbeck silty clay soils (Section 1.5). Selected <br /> physical and chemical properties for the soil types are listed in the following table. <br /> Table 8. <br /> Physical and Chemical Properties* <br /> Soil Name l depth USDA Unified Sol Clay Permeability SOO salinity Septic tank <br /> Map reaction absorption <br /> Symbol tin} Texture Classification (rite} (In1l�aur)Symbol (pH) (mmhaslcm) fields <br /> 4-i0 Silty clay CH,CL 0 0.14-0.16 6.6.8.4 <2 <br /> 60 <br /> Hdienbeck 10-37 Clay,silty CH.CL 40- 0.14-0.16 6.6-8.4 <2 <br /> slllyclay clay Be severe pens <br /> 173 Silly clay 30- 0.17-0.20 6.6-0.4 c2 slowly <br /> 37.42 loam,clay GL 40 <br /> loam <br /> 4i-s oemenled <br /> 'Selected USDA physical and chemical properties <br /> 2.1.2 Mass Transport Soil Properties <br /> The longer the effluent remains near the surface, the more treatment is enhanced due to natural <br /> processes within the soil. Based on the relatively slow percolation rates and stiffness of the soils <br /> at depth (25 feet tags), effluent is anticipated to remain within the soil column. <br /> Responsive r Resourceful a Reliable 14 <br />