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01 April 2021 AdvancedGeo Project No. 21-6365 An Employee-Owned Company Page 10 of 15 7.2. MASS TRANSPORT PROPERTIES OF UNDERLYING SITE SOILS The percolation test and dominant soil type at the site indicates that the soils are permeable and have low water storage. These soils will allow moderate to high 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 the onsite domestic water well located to the east of the existing residence (Figure 2). 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 DWR SGMA Data Viewer for Spring 2020, depth to groundwater at the site is approximately 25 to 30 feet bsg. Between 2011 and 2019, depth to groundwater at the site has fluctuated between 20 and 40 feet bsg. Groundwater flow direction locally appears to be toward the east. Groundwater was not encountered in the 42-inch-deep percolation test hole advanced on 22 March 2021. 8.2. EXISTING OR POTENTIAL GROUNDWATER CONTAMINATION The immediately adjacent and outlying land use for the parcel is residential. 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 four (4) LUST sites within a 2,000-foot radius of the subject property. The LUST sites have been closed since 1999 and based on the status of the site and the distance and direction from the subject property, the site should not impact the subject property. The review did not reveal any other sites of environmental concern within a half-mile radius of the site. Based on the information reviewed, there is no existing or known groundwater contamination at the site and the potential for groundwater contamination is de minimis. 8.3. CURRENT AND FUTURE USE OF GROUNDWATER AT THE SITE The existing water supply well at 2111 Waudman Avenue (site) likely conforms to DWR and EHD standards. Permits could not be located for the installation and construction