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3. Section 4.3.4.2,Pesticides,Page 4-30: This section notes that U.S.Environmental Protection <br /> Agency(EPA)Region 9 preliminary remediation goals (PRGs) from 1991 were used as the basis <br /> for the final remediation goals derived for the Pesticide Mix Area,but the PRGs evolve <br /> continually based on new risk assumptions and toxicity data.For example,the PRGs from 2002 <br /> (EPA,2002)use a new value for outdoor worker soil ingestion rate that is twice as high as the <br /> previous rate(100 milligrams [mg]/day vs. 50 mg/day). In light of the continual change in risk <br /> assumptions used in the PRGs,please explain in the appropriate sections of the Report whether <br /> the toxicity data used at the time of remedy selection are still protective for the Pesticide Mix <br /> Area or other areas that may have had cleanup levels based on older PRGs. <br /> 4. Section 6.4.2.5,TCE and PCE in Potable Water Wells,Page 6-4: This section states that 0.5 <br /> micrograms per liter(ug/L)is the Maximum Contaminant Level (MCL) for tetrachloroethylene <br /> (PCE),but 0.5 ug/L is the Aquifer Cleanup Level (ACL)for PCE and 5 ug/L is the MCL for <br /> PCE. Please revise the section to clarify the distinction between the MCL and the ACL for PCE. <br /> 5. Section 6.5, Site Inspection,Page 6-7,and Attachment 4,Photograph Log: The text in this <br /> section cites Attachment 4 in the single-paragraph discussion of the site inspection,but it is not <br /> clear that the site inspection followed the Guidance. The Guidance states that,the site inspection <br /> should be "recent"and defines recent as no more than nine months before the expected signature <br /> date of the Five-Year Review(EPA,2001, Section 3.5.3,Page 3-5).The text does not state the <br /> date of the site inspection, include the names of those conducting the site inspection or discuss <br /> any specific findings from the site inspection.In addition,the color photographs in Attachment 4 <br /> are undated and the black and white photographs are dated 1994 and 1995.Please revise this <br /> section to provide additional discussion of the site inspection, including dates to document that <br /> the site inspection was recent as defined by Guidance. In addition,please provide the site <br /> inspection report as an attachment to the next version of the Report,including dates,names of <br /> inspectors, and additional photographs in Attachment 4 to document the current condition of the <br /> remedies at DDJC-Sharpe,including the ICs in the South Balloon area. <br /> 6. Section 7.2.1,OU 2 Soil Remedial Actions(VOCs),Page 7-10: The ROD and the Report both <br /> clearly state that volatile organic compound(VOC) soil remedial actions at DDJC-Sharpe were <br /> implemented to prevent impacts to groundwater,but toxicity data have changed recently for TCE <br /> that should be addressed in the Report to demonstrate that the VOC soil remedy is still protective <br /> of human health via the inhalation pathway. Specifically,the 2002 Region 9 PRG for TCE(EPA, <br /> 2002)uses provisional cancer slope factors developed by the EPA's National Center for <br /> Environmental Assessment(NCEA)in their recently released toxicity assessment for TCE. <br /> These slope factors are an order of magnitude higher than the previous slope factors from the <br /> California Office of Environmental Health Hazard Assessment(OEHHA),which have typically <br /> been the basis for risk assessments done in California. Please revise the Report to discuss the <br /> 2 <br />