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4.0 GROUNDWATER ANALYSIS 4.1 Description of the depth to groundwater, seasonal fluctuations of groundwater depth, directional flow and gradient: Description of depth to groundwater, seasonal fluctuations of groundwater, directional flow, and gradient are referred to in Section 4 of the Soil Suitability Report prepared by Dillon & Murphy that is attached in the Appendix. 4.2 Description/discussion of any existing and/or potential groundwater contamination issues in the general location of the site: Description of existing or potential groundwater contamination issues in the general location of the site are referred to in Section 4.2 of the Soil Suitability Report prepared by Dillon & Murphy that is attached in the Appendix. 4.3 Description of the current use of groundwater at the site and of the future expected use of groundwater as related to the proposed development project: The depth to ground water in this area is approximately 25 +/- feet according to the map of"Lines of Equal Depth to Groundwater" published Spring 2024, by the San Joaquin County Flood and Water Conservation District. The gradient descends from east to west. This was verified with the California Department of Water Resource's Water Data Library. The results of the historic depth to ground water show that the relative depth has not changed drastically throughout the years. The proposed improvements will not have a negative effect on the current depth to ground water. See appendix for the site's depth groundwater tables and diagrams. 5.0 SOURCES AND CALCULATED IMPACT OF NITRATE TO GROUNDWATER 5.1 Description of all current off-site sources of nitrate to soil and groundwater in the general up gradient area and the contribution of nitrate load from these sources to the project site: Current off-site source of nitrate to soil and groundwater in the general up gradient area are increased by the contribution of nitrate loads from agricultural and residential sites with septic systems with minimal impact to the site. The neighboring sites are all residential or agricultural with no major sources of pollution that could affect this project site. The nearest major source of pollution is the Sharpe Army Depot located 0.6 miles south of this project. There is no record of past contamination reaching this or neighboring parcels. 5.2 Description of impact of rainfall contribution of nitrate load to the project site: The impact of rainfall contribution on the project site was completed to determine the nitrate load. The average monthly precipitation and evapotranspiration are required to calculate the site nitrate load. These two values are used to estimate the deep percolation. The annual rainfall recharge is estimated by analyzing the difference between the monthly average precipitation and the evapotranspiration when the precipitation exceeds the monthly average evapotranspiration. These calculations are attached in the Appendix. 2