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Ms. Dink Mather <br /> March 8, 2000 <br /> Page 3 <br /> 2. Text states petroleum-affected soils were observed from 7 to 14 feet bgs. However, the ta- <br /> bles reflect the depths as 8.5 to 11 feet bgs. The text should be revised appropriately. <br /> 3. HERD reproduced the risk screening calculations. The risk calculated for the property was <br /> at 1 x 10-6, which is within the range that is, considered acceptable (1 x 106 to 1 x 10-4). The <br /> risk calculations were based on the use of the equivalent of"J" qualified (estimated) data. <br /> The risks were calculated fora hypothetical, future resident at the site. <br /> Conclusions and Recommendations <br /> The analytical data supporting this investigation appear adequate both in quantity and quality. <br /> Detection limits were sufficiently low to support the intended end-use of the data. The screening <br /> risk evaluation used the methodology and equations presented in the PEA. <br /> The residual soil contamination appears to be a small layer of soil approximately 2 feet thick at <br /> approximately 8 feet bgs. The residual levels of petroleum-related hydrocarbons in the soils at <br /> the site are below levels that would constitute an unacceptable risk to human health and the en- <br /> vironment as evidenced by a cancer risk of less than 1 x 10-6 and a hazard index of less than <br /> 1.0. This meets the criteria for a "no further action" determination as outlined in the PEA man- <br /> ual. <br /> Please contact me at [(916) 327-2510] or e-mail at dberry@dtsc.ca.gov if you have any ques- <br /> tions regarding the evaluation of the above document. <br /> Reviewed by: Stephen DiZio, Ph.D. <br /> Senior Toxicologist, HERD <br /> i <br /> i <br /> s <br /> F <br /> i <br />