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10) Page 6-7/Section 6. 2.4.4: The last sentence presumes that the cancer risks established in the risk assessment may be as low as zero. This sentence has no factual basis and should be deleted. 11) Pages 6-9 and 6-10/Section 6.2 .5. 1: This section provides an excellent definition of the constraints employed in the OU - 1 RA. It is recommended that this section be reiterated at the beginning of Section 6. 12) Page 7-2/Section 7 . 1. 1. 3 : The monitoring program outlined in the Draft ROD consists of two years of quarterly monitoring followed by bi-annual monitoring. For costing purposes, the bi-annual monitoring was extrapolated out for 28 additional years. A rigid monitoring program that does not take into account real time analysis of gathered data is unacceptable. The length and frequency of ground water monitoring should be based on the analysis of the data. It is recommended that the monitoring program be re- written to reflect this approach. 13) Page 7-3/Section 7. 1. 2. 3. 3: The section describes DDRW, Tracy's program to mitigate the impact to residents who's wells have been contaminated by TCE and PCE. To date, mitigating actions have consisted of a continuous supply of bottled water. The Department does not consider this to be a final mitigation response and recommends that DDRW, Tracy consider more appropriate long-term actions. 14) Page 7-10/Section 7 .3 . 1. 1. 1: The discussion of the ground water extraction system does not portray the remediation concept agreed to by the regulatory agencies. As depicted, the extraction system provides a fence line approach for ground water remediation. DDRW, Tracy has agreed with verbal regulatory comments to incorporate hot spot removal and total plume remediation into extraction system design. This should be reflected in the ROD presentation. Figures 7 . 3-1, 7. 3-2, and 7. 3-3 should also be adjusted. -3-