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4.0 GROUNDWATER ANALYSIS <br /> 4.1 Description of the depth to groundwater, seasonal fluctuations of groundwater depth, <br /> directional flow and gradient: Description of depth to groundwater, seasonal fluctuations of <br /> groundwater,directional flow and gradient are referred to in Section 4 of the Soil Suitability Report <br /> prepared by Dillon& Murphy that is attached in the Appendix. <br /> 4.2 Description/discussion of any existing and/or potential groundwater <br /> 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(See 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 /> Based on the most recent results from San Joaquin County's "Flood Control and Water <br /> Conservation District" report on groundwater from Fall of 2017, the estimated depth to <br /> groundwater was determined to be 100 feet below the surface. This was verified with the California <br /> eepartment of Water Resource's Water Data Library. The results of the historic depth to ground <br /> water show that the relative depth has not changed drastically throughout the years. It fluctuates <br /> minimally on a yearly basis. The pro,posodimpmvements-will not-have-u-.negative-effecLon,tb , <br /> currentde <br /> site'septh groundwater tablesanddiagrams. <br /> proposed usage <br /> is less than thatof, agricu�,. See appendix <br /> for the <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. Both d_parcels d rLnt hwm an-� house but it was <br /> assumed that both lot, ae�raging e same acreage had a hous in,tbe.prep.aration-ok4i �e� <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 �-regional Climate C' •n x (Statiou.70) for the Staten-Island-regionau <br /> estimate of the deep percolation of rain for the project was determined. <br /> 2 <br />