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cleanup standards (and include the fact that there is also a cleanup standard for DCE set by the state MCL). 89. Section 7.4.2.2.1 This section erroneously implies that the OSHA requirements are ARARs. Corrective Action: Delete the OSHA requirements (as ARARs). 90. Section 7.4.2.3 The text indicates that cost-effectiveness is reevaluated at the 5 year review. However, the intent of the 5 year review is to evaluate the protectiveness of the remedial action. Corrective Action: Please cite the source of the assertion that the 5 year review is an opportunity to reevaluate the cost-effectiveness of the remedy, or delete the statement. 91. Section 7.4.2.3 While it is reassuring to state that effluent standards will be maintained that will not cause degradation of the aquifer, the ROD must explain how monitoring of the influent will be performed to assure that should other chemicals of concern be detected at levels which might cause degradation of the aquifer, it may be necessary to establish additional effluent standards. Corrective Action: Add to the text a commitment to monitor influent for all potential contamination and to establish additional effluent standards as necessary. 92. Section 7.4.2.3.2 The FS included a discussion concerning possible cross-contamination in wells screened in both the upper and middle horizons, however, this concern is not presented in the ROD. Corrective Action: Add the discussion regarding potential cross-contamination and include a statement which explains the actions DDRW-Tracy will take to address this concern. 93. Section 7.4.2.3.3 It is not correct to state that at the end of remediation there will be "no risk.", Corrective Action: Modify the text to state that at the end of remediation risks will be reduced to acceptable levels (i.e., to the range stated in the NCP, 1x10-* to 1x10-8). EPA/R9 June 7, 1993 21/40