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Page 4 September 10,2012 DBrusca Project No. 114-001.01 1813 Moffat Boulevard Property,Manteca Teflon tape and plastic end caps, labeled, placed on ice, and transported under chain-of-custody documentation to a State-certified laboratory for analysis. Following the drilling and sampling activities, each boring was back-filled with neat-cement grout, and the pavements were patched at the boring locations. LABORATORY ANALYSIS The collected soil samples were submitted to a State-certified laboratory (Sunstar Laboratories, Inc.; ELAP No. 2250) for analysis for gasoline-, diesel-, and motor oil-range petroleum hydrocarbons, as well as volatile organic compounds (VOCs). Selected samples also were tested for CAMS metals or Title 22 metals. The results of the soil analyses are summarized on Table 1. The laboratory report and chain-of-custody documentation are attached. RESULTS AND DISCUSSION The laboratory results are favorable. None of the soil samples tested contained VOCs at concentrations above the laboratory reporting limits. Only two of the 13 soil samples tested contained petroleum hydrocarbons at concentrations above the laboratory reporting limit. The five-foot deep soil sample from Boring BI (situated near the sump) contained a very low concentration of motor oil-range petroleum hydrocarbons (110 mg/kg). The five-foot deep sample from Boring B3 (also situated near the sump) contained very low concentrations of diesel-and motor oil-range petroleum hydrocarbons(130 mg/kg and 56 mg/kg, respectively). To evaluate the significance of the petroleum hydrocarbons detected in the soil samples collected near the sump, we have compared the analytical results to Environmental Screening Levels (ESLs) developed by the California Water Quality Control Board? The ESL values published by the Water Board were developed for common contaminants considering protection of human health, drinking water resources, vapor intrusion into buildings, aquatic habitats, and terrestrial biota. The referenced screening values are neither regulations nor clean-up standards; rather the screening levels are advisory values above which the agencies suggest additional site evaluation. As such, the referenced screening values are considered conservative for use for screening-level evaluation. The applicable petroleum hydrocarbon ESL values for residential and commercial/industrial exposure scenarios are shown on Table I along with the soil analytical data from the site. As shown, none of the detected concentrations of petroleum hydrocarbons detected in the soil samples exceeds the ESL values for commercial/industrial sites. As such, the very minor and localized petroleum hydrocarbons in shallow soils near the sump are not considered a significant environmental concern. It is noted that the concentration of diesel-range petroleum hydrocarbons detected in the five-foot deep soil sample from Boring B3 slightly exceeds the ESL value for residential sites; however, future residential use of the property seems unlikely. 2 California Regional Water Quality Control Board, San Francisco Bay Region; "Screening for Environmental Concerns at Sites with Contaminated Soil and Groundwater";Interim Final—November 2007(Revised May 2013).