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30 August 2019 <br />AGE Project No. 19-4819 <br />Page 10 of 15 <br /> <br />8.0. GROUNDWATER ANALYSIS <br /> <br />The subject property is supplied with potable water by the onsite domestic water well <br />located in the northwest quadrant of the site (Figure 2). A groundwater sample was <br />collected from the well and analyzed for nitrates as part of this study. <br /> <br /> <br />8.1. DESCRIPTION OF LOCAL GROUNDWATER <br /> <br />According to the San Joaquin County Flood Control and Water Conservation District’s <br />Lines of Equal Depth to Groundwater Fall 2018 and the DWR Water Data Library, depth <br />to groundwater at the site is approximately 20 to 30 feet bsg. Groundwater flow direction <br />locally appears to be toward the north. Groundwater was not encountered in the 42-inch <br />deep percolation test hole on 22 August 2019. <br /> <br /> <br />8.2. EXISTING OR POTENTIAL GROUNDWATER CONTAMINATION <br /> <br />The immediately adjacent and outlying land use for the parcel is residential and <br />agricultural. Potential groundwater contamination can occur from several sources <br />including leaking underground storage tanks, septic systems, agricultural activities, <br />dairies, and stormwater infiltration. A review of the DTSC EnviroStor Database and the <br />Geotracker Web site did not reveal any sites of environmental concern within a half-mile <br />radius of the site. Based on the information reviewed, there is no existing or known <br />groundwater contamination at the site and the potential for groundwater contamination is <br />de minimis. <br /> <br /> <br />8.3. CURRENT AND FUTURE USE OF GROUNDWATER AT THE SITE <br /> <br />The existing water supply well at 17454 Von Sosten Road (site) conforms to DWR and <br />EHD standards and is used to supply the subject property with a domestic water source. <br /> <br /> <br />9.0. IMPACT OF NITRATE TO GROUNDWATER <br /> <br />Due to the residential use of the property and the potential for nitrate leaching into the <br />groundwater from the existing and proposed septic systems, a nitrate loading analysis for <br />the future use of the septic systems is required by the EHD. <br /> <br /> <br />9.1. CURRENT OFF-SITE SOURCES OF NITRATE <br /> <br />Septic systems and agriculture are sources of nitrates in the area of the site. The property <br />is bordered by agricultural and residential lands which might provide a nitrate source. <br />There are several residences within 1,000-feet of the site.