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18 September 2020 AdvancedGeo Project N o. 20-6116 An Employee-Owned Company Page 10 of 15 The USDASGD soil survey indicates the soil type for the western portion of the subject property is predominantly composed of Veritas fine sandy loam having 0 to 2 percent slopes (#266). The Veritas fine sandy loam is composed of alluvium derived from mixed rock sources. Soils are described as moderately well drained, with low permeability, and salinity ranging from 0.0 to 4.0 millimhos per centimeter (mmhos/cm). The Veritas fine sandy loam typically has the same chemical properties between surface grade and 54 inches bsg 7.2. MASS TRANSPORT PROPERTIES OF UNDERLYING SITE SOILS The percolation test and dominant soil type at the site indicates that the soils are semi- permeable to permeable and have low to moderate water storage. These soils will allow moderate infiltration of water through the surface soils. The longer the effluent remains near the surface, the more treatment is enhanced due to natural processes within the soil. If the permeable soils exist to the depth of the groundwater table, it is possible that surface contaminants may be transported fairly rapidly. 8.0. GROUNDWATER ANALYSIS The subject property is supplied with potable and irrigation water by DW-1 (Figure 3). A groundwater sample was collected from the well and analyzed for nitrates as part of this study. 8.1. DESCRIPTION OF LOCAL GROUNDWATER According to the San Joaquin County Flood Control and Water Conservation District's Lines of Equal Depth to Groundwater Fall 2018 and the DWR SGMA Data Viewer, depth to groundwater at the site is approximately 20 to 30 feet bsg. Between 2011 and 2018, depth to groundwater at the site has fluctuated between 15 and 30 feet bsg. Groundwater flow direction locally appears to be toward the northwest. Groundwater was not encountered in the 42-inch deep percolation test hole advanced on 09 September 2020. 8.2. EXISTING OR POTENTIAL GROUNDWATER CONTAMINATION The immediately adjacent and outlying land use for the parcel is mostly agricultural with minor residential land use. Potential groundwater contamination can occur from several sources including leaking underground storage tanks, septic systems, agricultural activities, dairies, and stormwater infiltration. A review of the DTSC EnviroStor Database and the Geotracker Web site did not reveal any properties of environmental concern within a half-mile radius of the site.