Laserfiche WebLink
Soil Suitability&Nitrate Loading Study Page 12 <br /> Proposed Oak Farm Vineyards Expansion.Lodi CA <br /> Pmject No. 670.IC <br /> June 17,2013 <br /> 7.2 Nitrate Loading Calculation <br /> The following discussion summarizes the total nitrate loading from the proposed new system <br /> as well as the existing systems. An estimate is made of total nitrate load as calculated from a <br /> simple mass-balance approach. The Hantzsche and Finnemore model is then used to <br /> estimate the nitrate concentration in groundwater. The calculation worksheets are in <br /> Appendix E. <br /> The following table summarizes the flow-rate calculation for the anticipated septic system. <br /> system Personnel Ave.Daily Ef twnt Vot Waloted <br /> I•low Conc. N Ave- <br /> Existing Res Residents 150 GPD 44 mg/L 10.4 m IL <br /> Productlon/ras in Pull Time Employees 43 GPD 60 m 4.1 m <br /> /Pronmd/ Part Time Employees; 29 GPD 60 mpJL 2.7 raL <br /> Tasting Room Visitors 285 GPD 80 nnWL 36.1 m /L <br /> Events Full Time Employees 43 GPD 60 m L 4.1 mgiL <br /> (FWslinju Pan Ti mo Em to ms 29 GPD 60 mg/L 2.7 m L <br /> Guests 53 GPD 80 m L 6.7 m I. <br /> TOTALS 1 632 GPD 66.8 m <br /> The total load will be 632 GPD at 66.8 mg/L nitrate concentration. The Hantzsche and <br /> Finnemore model is then used to estimate the nitrate concentration in groundwater. The <br /> calculation worksheet(s)are in Appendix E. <br /> System Acres Dally Flow Effluent Denitnncadon Percolation N Loading <br /> Conc. N Factor d R <br /> 3 System Total 1 31 1 632 GPD 66.8 mgfL 25% 7.85 in. %lbs <br /> The existing and proposed septic systems will produce a total groundwater load of 96 pounds <br /> per year of nitrogen. This represents an average concentration at the groundwater surface <br /> 2.66 mg/L of nitrogen, or 27 percent of the established maximum contaminant limit of 10 <br /> mg/L. The future system is estimated to result in nitrate loading to groundwater that will not <br /> exceed the MCL limit. This calculation does not consider the dilution that occurs as newly <br /> introduced water mixes with the deeper groundwater. The calculated groundwater <br /> concentrations offer a "worst case" estimate. The existing nitrate level from the laboratory <br /> analysis of well water is 26 mg/L which converts to 5.9 mg/L of nitrogen. The total nitrogen <br /> as nitrogen. ll-three septic systems plus the existing groundwater nitrate would <br /> therefore"6 m (2. 5.9 hich is less than the MCL concentration of 10 mg/L. <br /> 2937 Veneman Ave..=112.10 Gen-1'hau Pmlronmental Inc. Phone: (209)569-0293 <br /> Modesto,CA 95311: Fax: (209)569-0293 <br />