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from b.0 to 11 mg/kg. No lead was detected in the groundwater samples. Lead was used as a gasoline additive for many years in the form of tetraethyl lead. According to the American Society for Testing and Materials (ASTM) Guidance Document for Risk-Based Corrective Action Applied at Petroleum Release Sites (ASTM E1739-95), tetraethyl lead decomposes to inorganic lead in dilute aqueous solutions and in contact with other environmental media. It remains as organic lead in free gasoline product; however, no free product was observed at the site. Since no organic compounds (petroleum hydrocarbons) were found at the locations where lead concentrations were detected, it is reasoned that the lead is in an inorganic state. US EPA Region IX.Preliminary Remediation Goals (May 1998) for inorganic lead in soil are .130 mg/kg for residential soils and 1,000 mg/kg for industrial soils. The.lead concentrations. found at the site are much lower than these remediation goals. Published background data for lead in soils in the western United States has an arithmetic mean of 20 mg/kg with a concentration range from less than 10 to 700 mg/kg (based on "Element Concentrations in Soils and Other Surficial Materials of the Conterminous United States", U.S. Geological Survey Professional Paper 1270, 1984). Since the soil samples were collected in an area peripheral to the former excavation and no PHCs were detected in these soils, it is reasoned that the lead concentrations detected are background levels for the area. In addition, lead concentration in all samples are far below total threshold limit concentration (TTLC) value of 1,000 mg/kg. The TTLC value, per Title 22 of the California Code of Regulations (CCR), is the concentration of a solubilized, extractable and nonextractable bioaccumulative or persistent toxic substance which, if equaled or exceeded in a waste, renders. the waste j hazardous. 5.0 CONCLUSIONS AND RECOMAMNDATIONS No indications of PHCs in soils or groundwater were found at this site. The total lead concentrations found in soils are within the range of background levels for the area and well below the TTLC values set by the State and the preliminary remediation goals set by the US EPA. Based on the results of this investigation, there is no recognized environmental condition which might constitute a :threat to human health and safety. It is therefore B&Rs recommendation that no further site investigation or remedial action is necessary at .this site. 6 981 MNvRPTsls4usrINv.RPT