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Nitrate Loading Study Ireirracon <br /> Morris Property r� Ripon, California <br /> September 12, 2018 a Terracon Project No. NA187039 <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 as N. The United States Environmental <br /> Protection Agency (EPA) maximum contaminant level (MCL) for nitrate as N in drinking water is <br /> 10 milligrams per liter (mg/Q. <br /> 1.0 CHEMICAL AND PHYSICAL SOIL PROPERTIES <br /> 1.1 Chemical and Physical Soil Properties <br /> Terracon reviewed the United States Department of Agriculture (USDA) Natural Resources <br /> Conversation Service (NRCS) Web Soil Survey and USDA Soil Survey of San Joaquin County <br /> (1992) for information regarding soil properties. Based on information obtained from the USDA <br /> sources, site soils consist of two soil types including Delhi loamy sand and Timor loamy sand. <br /> Selected physical and chemical properties for the soil types are listed in the following table. <br /> Table 1. <br /> Physical and Chemical Properties* <br /> Soil Septic <br /> Soil Salinity <br /> Name I Depth USDA Unified Soil Clay Permeability tank <br /> Map (in) Texture Classification (%) (in/hour) reaction (mmho absorption <br /> Symbol (pH) slcm) fields <br /> 0-16 loamy sand .........................._SM.....................................0.-5..........................._6 0-20..............................6.:_�..-7.:8.........................._.<..�................. <br /> Delhi/ _......................_...................... ..... Severe; <br /> 16-26 loamy sand sM...................................._0-5..........................._6:_0-20..............................6.:.1..-7.8........................._..<..�................. poor filter <br /> 142 26-60..............._._._..sand........................................SP-SM 0-5 6.0-20 6.1-7.8 <2 p <br /> 0-14 loamy sand ......................._SM................................._2.-.�_0........................_6.0-20............................._6.:6-7:8.........................__<..2................. <br /> Timor/ .............. ...... ......... Severe, <br /> 14-56 loamy sand SM 2-10 6.0-20 7.4-8.4 <2 <br /> 254 .................................._ . .... .... ........ ........._............ ........... poor filter <br /> 56-60 cemented --- --- --- --- --- <br /> 'Selected USDA physical and chemical properties <br /> 1.2 Mass Transport Soil Properties <br /> The below additional information pertaining to mass transport for each soil type was obtained <br /> from the USDA sources listed in Section 1.1. <br /> Delhi loamy sandy soils are located across approximately 45% of the southwestern portion of the <br /> site and consist of somewhat excessively drained soils. Delhi loamy sandy soils have rapid <br /> permeability and slow runoff. The rate of water in-take in irrigated areas is anticipated at 3.0 <br /> Responsive ■ Resourceful ■ Reliable 3 <br />