SITE INFORMATION AND CORRESPONDENCE

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--- - .....---- ...__. ..., Philip Isorena Jim Carlisle May 7, 2004 Page 2 has previouslybeen concerned about gradient and off-site migration and has requested that Chevron conduct further investigation to delineate the extent of the sub-surface crude oil detected on the water table. In addition, the Hoff'mans remain very concerned as to the distribution of the residual crude oil leftover from the station's closure in 1957. Although the Board has developed a protocol for handling oil line pumping stations,the Lyoth Loading Station is different. The fact that the ponded crude was burned off and then essentially buried across the property further raises questions as to the extent of the investigation conducted to date to ascertain the existence of additional pockets of known carcinogens. The two areas identified by Geomatrix as the problem areas at the site could adversely affect the development of the property as a residential site. The risk assessment performed by Geomatrix indicated that risks in excess of 10 are present as the result of benzene and benzo(a)pyrene in soil sampled in the former"GP-3"tank pit area. Risks in excess of 10'8 are present in the subsurface soil in the pipeline area. Chevron claimed in a February 26, 2002 correspondence to Jim Carlisle at the Office of Environmental Health Hazard Assessment that the Health and Risk Assessment(HRA) has stated that the results of the HRA conclude no action is necessary to meet a residential scenario, but this is a claim unsupported by regulatory concurrence. Chevron,in the February 26,2002 memorandum to Mr. Carlisle, is essentially claiming that any risk under 10'is acceptable. Given the potential for a residential scenario,a 10"threshold is not appropriate. in many situations, risks in excess of 10"or 10.6 mayrequire remedial or other corrective action and it is within DTSC's discretion to determine the appropriate level for acceptable risk. Gvcn the foregoing circumstances,the Hoffmans are requesting a concurrent investigation tinder the respective jurisdictions of the Regional Water Quality Control Board,as well as the Department of Toxic Substances Control, to ensure that a full and complete characterization of the potential threat to public health, safety and the environment posed by the historic activities of Standard Oil and Chevron Oil companies on their property is conducted. Sincerely, Jeffery J. Scharff JJS1hv cc: Clients NftCUCMN Ac¢WNMr, 0IV.V004\Rrp IAWr IU Oi306i.npd 5594455910 => CHEVRON EMC TEL=9258420213 05/11 '04 15:25