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20 July 2021 AdvancedGeo Project No. 21-6486 An Employee-Owned Compony Page 10 of 15 Database (USDASGD). The USDASGD soil survey indicates the soil type for the property is predominantly composed of Tokay fine sandy loam having 0 to 2 percent slopes (#256). The Tokay fine sandy loam is composed of alluvium derived from granitic sources. Soils are described as well drained, with moderate permeability, and salinity ranging from 0.0 to 2.0 millimhos per centimeter (mmhos/cm). The Tokay fine sandy loam typically have similar chemical properties and soil profile between surface grade and 45 inches bsg. The Tokay fine sandy loam is slightly coarser from 45 to 60 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 and have 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 water by two (2) onsite domestic water wells located to the south of the larger residence and to the north of the smaller residence (Figure 2). A groundwater sample was collected from each well and analyzed for nitrates and DBCP as part of this study. 8.1. DESCRIPTION OF LOCAL GROUNDWATER According to the DWR SGMA Data Viewer for Spring 2020, depth to groundwater at the site is approximately 75 feet bsg. Between 2011 and 2019, depth to groundwater at the site has fluctuated between 75 and 95 feet bsg. Groundwater flow direction locally appears to be toward the east-southeast. Groundwater was not encountered in the 42-inch-deep percolation test hole advanced on 30 June 2021. 8.2. EXISTING OR POTENTIAL GROUNDWATER CONTAMINATION The immediately adjacent and outlying land use for the parcel is residential and agricultural. 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 revealed one (1) LUST site within a half-mile radius of the subject property. The LUST site has been closed since 1998 and based on the status of the site and the distance and direction from