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13. Page 4-1, Section 4.3.3.1 Many exposure pathways have been examined and exposure parameters presented. This site-specific information should be used to compute preliminary remediation goals (PRGs) for the site replacing the generic PRGs developed by EPA Region IX. 14. Page 4-1, Section 4.3.3.1, Sentences 5 and 6 The text states "However, in certain (rare) instances there are alternative analytical methods that could be used to lower the detection limits a small amount, but only at a high cost. The method that would obtain the lower detection limits was rejected oily whet? the lower limits would not significantly improve the risk assessment." • These sentences are not relevant to the BRA work plan; they represent opinion and should be deleted. 15. Page 4-2, Section 4.3.3.2 The text refers to the "recalculation" of some PRGs but is silent on the exposure scenario used. • Include an explanation of the exposure scenario in the document. 16. Page 4-2, Section 4.3.3.2 The last sentence of this section indicates a lack of information prevented a reevaluation of organics. However, information regarding Henry's law constants (H) and organic carbon partition coefficients (Kee) can be found in the RI report for Operable Unit No. I (OU No. 1).* • Please explain in the Amendment why this information is not sufficient or explain more completely why the organics were not reevaluated. 17. Page 4-3, Section 4.3.3.4.2, Sentence 2 State the text the risk at the proposed detection limits for arsenic, beryllium, and thallium. 18. Page 4-3, Section 4.3.3.4.2, Sentence 3 State, in the text, the numerical difference in risk between the detection limits. 19. Page 4-3, Section 4.3.3.5.1, Sentence 3 f i This sentence should read "there is no significant risk reduction with this alternative method." USEPA/R9 12 Apr 93 6/19