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5.2 Laboratory Results , Analytical results for soil and groundwater samples collected from this investigation are summarized in , Table 1. Reported concentrations reviewed from the laboratory report were compared to the US Environmental Protection Agency-Region 9, Regional Screening Levels (RSLs) and the California Human Health Screening Levels (CHHSL). Reported concentrations were also compared to the ' California Regional Water Quality Control Board, San Francisco Bay Region in Screening for Environmental Concerns at Sites with Contaminated Soil and Groundwater; Volume 1: Summary Tier 1 Lookup Tables, November 2007 Updated May 2008, Table B, shallow soil (<3M BGS), Table D, Deep ' Soil (>3M BGS) — Water is not a Current or Potential Source of Drinking Water ("Environmental Screening Level's" [ESLs] for Industrial Soils). The ESLs were used as a comparative general reference. Review of the analytical data for analyzed soil samples indicates the following: ' • Laboratory analysis of soil samples identified various metals in soil samples collected from the site ' and analyzed, including; arsenic, barium, chromium, lead, and selenium. With the exception of arsenic,the reported metal concentrations were below the regulatory RSLs and comparative ESLs. The concentrations of arsenic in the analyzed soil samples from Boring Bl and Boring 136 ranged ' from 5.3 to 17 mg/kg. The specific concentrations of each sample are noted in Table 1 of this report. The identified concentrations of arsenic in soil samples from the site were compared to reported background levels of arsenic in soil across California as stated in Element Concentration in Soils and ' Other Surficial Materials of the Conterminous United State written by Hansford T. Shacklette and Josephine G. Boerngen. Background levels for arsenic in the general area were reported in this document at a mean concentration of 5.5 mg/kg with an observed range of<0.10 to 97 mg/kg. The ' reported concentrations of arsenic in soil samples from the site are near and slightly above the reported mean concentration of Shacklette and Boerngen, but within reported background levels. In addition, the concentrations of arsenic in the soil samples from various locations across the site appear to be more or less consistent without significant variation suggestive of a potential source(s)of ' contaminant or primary area(s) of concern. Additionally, the entirety of the subject property is covered by buildings, concrete foundations, and/or asphalt, which generally serves as a confining cap and preventing direct exposure. As such, arsenic in the soil samples from the site appeared to be ' within background concentrations; and relatively immobile in the subsurface due to the presence of a confining cap,which also prevents direct contact and exposure to soils at the site. • Laboratory analysis of soil samples identified concentrations of TPH-DRO at 2,900 mg/kg in B3-Sl; ' 1,700 mg/kg in B3-S2; 12 mg/kg in B3-S3; and 410 mg/kg in B4-S1. The detected concentrations of TPH-DRO, with the exception of B3-S3, were reported at concentrations above the comparative ESL of 183 mg/kg for industrial sites where groundwater is not a current or potential source of drinking ' water. The RSLs do not include a regulatory level for TPH-DRO. • Analysis of soil sample B4-S1 identified acetone at a concentration of 0.025 mg/kg which is ' significantly below the RSL of 630,000 mg/kg and ESL of 0.50 mg/kg. Laboratory analysis of the remaining soil samples did not identify any other concentrations of VOCs above the LLD. In addition, no soil samples collected and analyzed identified concentrations of TPH-GRO above the ' LLD. Limited Subsurface Investigation (J8D Trust)J&D Auto Body 7 f�UCfl� 1011 Cherokee Lane, Lodi, California