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NitrateLoadingStudy lrerracon <br /> Rowe Property r Lodi, CA <br /> November 6, 2017 ■ Terracon Project No. NA177059 <br /> The Hantzsche and Finnemore 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 B. The units <br /> of nitrate used in the mass balance equation are nitrate-N, whose maximum drinking water <br /> contaminant level (MCL) is 10 mg/L. <br /> 1.0 CHEMICAL AND PHYSICAL SOIL PROPERTIES <br /> 1.1 Chemical and Physical Soil Properties <br /> Based on a review of the United States Department of Agriculture (USDA) Natural Resources <br /> Conversation Service (NRCS) Web Soil Survey (https://websoilsurvev.sc.egov.usda.gov), site <br /> soils consist of the following two soil types: <br /> Tokay fine sandy loam <br /> Tokay fine sandy loam soils are located across the site and consist of well drained soils with 0 to <br /> 2 percent slopes. Parent materials consist of alluvium derived from granitic rock sources. Typical <br /> soil profiles consist of 0 to 19 inches fine sandy loam, 19 to 45 inches fine sandy loam, and 45 to <br /> 60 inches sandy loam. <br /> 1.2 Mass Transport Soil Properties <br /> Based on a review of the USDA Soil Survey of San Joaquin County California (Issued 1992), <br /> Tokay fine sandy loam soils are very deep, well drained soils which have moderately rapid <br /> permeability. <br /> The longer the effluent remains near the surface, the more treatment is enhanced due to natural <br /> processes within the soil. If permeable soils exist to the depth of the groundwater table, it is <br /> possible that surface contaminants may be transported fairly rapidly; however, the groundwater <br /> depth is relatively deep and the near surface permeable soils are likely underlain by interstratified <br /> finer grained soils. <br /> 2.0 GROUNDWATER ANALYSIS <br /> 2.1 Regional Groundwater <br /> According to the California Department of Water Resources Groundwater Information Center <br /> (https://gis.water.ca.aov) Spring 2017 to Spring 2015 groundwater depth and elevation maps, <br /> groundwater depth lies between approximately 90 and 110 feet below grade surface (bgs) with <br /> Responsive ■ Resourceful ■ Reliable 3 <br />