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10 September 2020 AdvancedGeo <br /> An Employtt•Owned Company <br /> Project No. 20-6095 ...r <br /> Page 10 of 15 <br /> The Delhi-Urban land complex is composed of alluvium derived from granitic rock <br /> sources. Soils are described as somewhat excessively drained, with a high to very high <br /> permeability, and salinity ranging from 0.0 to 2.0 millimhos per centimeter (mmhos/cm). <br /> The Delhi-Urban land complex typically have the same chemical properties between <br /> surface grade and 60 inches bsg. <br /> 7.2. MASS TRANSPORT PROPERTIES OF UNDERLYING SITE SOILS <br /> The percolation test and dominant soil type at the site indicates that the soils are <br /> permeable and have low water storage. These soils will allow moderate to high infiltration <br /> of water through the surface soils. The longer the effluent remains near the surface, the <br /> more treatment is enhanced due to natural processes within the soil. If the permeable <br /> soils exist to the depth of the groundwater table, it is possible that surface contaminants <br /> may be transported fairly rapidly. <br /> 8.0. GROUNDWATER ANALYSIS <br /> The subject property is supplied with potable water by the onsite domestic water well <br /> located to the east of the existing residence (Figure 2). A groundwater sample was <br /> collected from the well and analyzed for nitrates as part of this study. <br /> 8.1. DESCRIPTION OF LOCAL GROUNDWATER <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 SGMA Data Viewer, depth <br /> to groundwater at the site is approximately 25 to 30 feet bsg. Between 2011 and 2018, <br /> depth to groundwater at the site has fluctuated between 20 and 30 feet bsg. Groundwater <br /> flow direction locally appears to be toward the north to northeast. Groundwater was not <br /> encountered in the 42-inch deep percolation test hole advanced on 02 September 2020. <br /> 8.2. EXISTING OR POTENTIAL GROUNDWATER CONTAMINATION <br /> The immediately adjacent and outlying land use for the parcel is residential. Potential <br /> groundwater contamination can occur from several sources including leaking <br /> underground storage tanks, septic systems, agricultural activities, dairies, and stormwater <br /> infiltration. <br /> A review of the DTSC EnviroStor Database and the Geotracker Web site revealed one <br /> (1) LUST site and one (1) former agricultural property with potential pesticide impact <br /> within a half-mile radius of the subject property. The LUST site has been closed since <br /> 2014 and the agricultural site has been closed since 2001. Based on the status of the <br /> sites and the distance and direction from the subject property, the sites should not impact <br />