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to the Upper Horizon (and Middle Horizon) and that additional extract and injection <br /> wells will be installed. <br /> Corrective Action: Revise this sentence to state " . . . and returned to the source <br /> aouifer via iniection wells and through the use of surface impoundments." <br /> 8. Declaration, Description of the Remedy <br /> This section appropriately contains signature spaces for the parties to the DDRW- <br /> Tracy FFA. However, DDRW-Tracy needs to identify those who sign. <br /> Corrective Action: For EPA, include under the signature block: John Wise, Acting <br /> Regional Administrator, Region IX, US Environmental Protection Agency. <br /> 9. Section 1.1.1 <br /> The ROD, a legally binding document, needs to be very clear on the definitions and <br /> decisions which are memorialized herein, and/or deferred. This ROD is complicated <br /> by the fact that the decision to set cleanup standards for some of the chemicals of <br /> concern is being deferred. This text, which presents a different definition for OU <br /> #1, inserts ambiguity into the ROD. (The definition in this section also erroneously <br /> omits that this ROD is addressing DCE.) The ROD needs to provide a careful and <br /> consistent explanation of the decisions (e.g., the cleanup standards being established) <br /> which are to be deferred to the Comprehensive RI/FS ROD. Refer the reader to a <br /> table to be included in Section 5.0 (see also subsequent EPA comments) which will <br /> help to clarify some of these issues. <br /> Corrective Action: Use the definition of OU #1 that is presented in the Declaration, <br /> as modified by EPA comments. <br /> 10. Section 1.2.2 <br /> By providing a detailed description of the current estimated boundary for OU #1, <br /> the text could erroneously be interpreted to mean this is a static definition regardless <br /> of possible future expansion of the groundwater plume. <br /> Corrective Action: Modify the description of the area of contamination to include <br /> the fact that the plume may continue to migrate prior to the time of remedial action <br /> and that the definition of OU #1 is not limited to the boundaries described herein. <br /> 11. Section 1.4.3 <br /> The text in the last sentence is confusing. The text also states "investigations to date <br /> that . . . TCE and PCE presently detected . . . have not been associated with <br /> continuing sources such as buried tanks or similar major 'sources'." Given that the <br /> SWMU investigations are just initiated, this assertion is premature. Further, it is <br /> unclear what is meant by "similar major 'sources'." <br /> EPA/R9 June 7, 1993 3/40 <br />