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DBCP is a nematocide and soil fumigant for vegetables and grapes. It is known to cause male reproductive effects and is classified as a probable human carcinogen. Most domestic use of DBCP was discontinued in 1977 through 1979. The US EPA set the MCL at 0.2 parts per billion (ppb, equivalent to ug/L) because it believes that given present technology and resources, this is the lowest level to which water systems can reasonably be required to remove this contaminant should it occur in drinking water. The Maximum Contaminant Level Goal (MCLG) for DBCP is zero. Soil Profile and Geologic Information The Site is mapped on the Preliminary geologic map of Cenozoic deposits of the Bellota quadrangle, California (Marchand, D.E., and Bartow, J.A., 1979). It is depicted within a map unit of the Modesto formation lower member, defined as "basin alluvium derived from the Mokelumne and Calaveras Rivers; includes arkosic alluvium, probably glacial outwash, and locally-derived materials; chiefly fine sand and silt" (Plate 11). The surface and near surface soils located at the Site are reported by the USDA Web Soil Survey to be composed of Jacktone clay (Plate 12) (USDA, 2019). The table below presents some selected properties of this soil: Table 1. Selected Properties of On-Site Soils (USDA, 1992) Soil Name Depth Unified Soil Salinity Soil Perme- Septic tank and Map /cm Reaction ability absorption Symbol (in) Classification mmhos pH (in/hr) fields Jacktone 0-22 Clay; CL, CH <2 6.6-8.4 0.06-0.2 Severe: clay, 0-2% 22-34 Clay loam, clay, silty <2 7.9-9.0 0.06-0.2 cemented slopes, clay; CL, CH pan, peres 180 34-37 Indurated --- --- --- slowly 37-46 Loam, clay loam; CL- <2 7.9-9.0 0.2-0.6 ML, CL 46-60 Cemented --- --- --- Note: The table descriptions do not necessarily reflect site-specific soil properties. See description of the map unit for composition and behavior characteristics of the map unit. Soil Borings On April 22, 2019, Live Oak excavated shallow soil borings near the proposed septic disposal areas of the Site for the purpose of conducting percolation tests. The borings were four inches in diameter, 3.29 and 3.32 feet deep, and were excavated by hand auger (Table 2). The locations of-fhe borings are indicated on Plate 13. The soil in the borings was similar to that described by the Soil Survey. Clayey silt was encountered to approximately 10 inches depth, followed by silty clay to the full depth of the hole. The soil log is presented on Plate 14. LOGE 1919 Page 5