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contamination issues in the general location of the site: Description of existing or potential <br />groundwater contamination issues in the general location of the site are referred to in Section 4.2 <br />of the Soil Suitability Report prepared by Dillon & Murphy that is attached in the Appendix. <br />4.3 Description of the current use of groundwater at the site and of the future expected use <br />of groundwater as related to the proposed development project: <br />The depth to ground water in this area is approximately 75 feet according to the map of "Lines of <br />Equal Depth to Groundwater" published Fall, 2021, by the San Joaquin County Flood and Water <br />Conservation District. The gradient descends from east to west. This was verified with the <br />California Department of Water Resource's Water Data Library. The results of the historic depth <br />to ground water show that the relative depth has not changed drastically throughout the years. The <br />proposed improvements will not have a negative effect on the current depth to ground water. See <br />appendix for the site's depth groundwater tables and diagrams. <br />5.0 SOURCES AND CALCULATED IMPACT OF NITRATE TO <br />GROUNDWATER <br />5.1 Description of all current off-site sources of nitrate to soil and groundwater in the general <br />up gradient area and the contribution of nitrate load from these sources to the project site: <br />Current off-site source of nitrate to soil and groundwater in the general up gradient area and the <br />contribution of nitrate loads are agriculture and neighboring sites with septic systems with minimal <br />to no current impact to the site. The neighboring sites are all residential/agricultural with no major <br />sources of pollution that could affect this project site. <br />5.2 Description of impact of rainfall contribution of nitrate load to the project site: The <br />impact of rainfall contribution on the project site was completed to determine the nitrate load. The <br />average monthly precipitation and evotranspiration are required to calculate the site nitrate load. <br />These two values are used to estimate the deep percolation. The deep percolation is estimated by <br />analyzing the difference between the monthly average precipitation and the evotranspiration, when <br />the evotranspiration exceeds the monthly average precipitation. These calculations are attached in <br />the Appendix. <br />The data for the potential evotranspiration water was obtained from the California Irrigation <br />Management Information System (CIMIS). The project is located within an area designated as <br />Zone 12. Based on the values for this area along with the average monthly precipitation values <br />obtained from the Western regional Climate Center for the Lodi region an estimate of the deep <br />percolation of rain for the project was determined. Station 262 in Linden had the most similar <br />weather and soil conditions to our project site. <br />The results for the deep percolation at the site were 7.94 in./year. The nitrate concentration is <br />estimated to be about 1 mg/L-N. (Hantzche and Finnemore, 1992). <br />5.3 Description of all current on-site sources of nitrate to soil and groundwater and the <br />contribution of nitrate load from these sources to the project site: The only source of nitrates <br />are the existing septic system in use by an existing parcel for residential uses. The existing septic <br />system was considered for when determining the approximate nitrate concentration, the site could <br />expect with the proposed development. <br />M <br />