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03 June 2021 A d vr,- r, Project No. 21-6431 ""E"'"°y" Page 10 of 15/� clay loam from 37 to 42 inches bsg, and cemented soils from 42 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 the onsite domestic water well located to the southeast 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 75 feet bsg. Between 2011 and 2019, depth to groundwater at the site has fluctuated between 55 and 95 feet bsg. Groundwater flow direction locally appears to be toward the northeast. Groundwater was not encountered in the 42 -inch - deep percolation test hole advanced on 17 May 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 did not reveal any LUST sites within 0.5 miles of the site. 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.