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c _ 2 _ 19 February 1993 �- Memorandum Geweke, 16 S. Cherokee, Lodi June because the annual sampling occurs in January. Some wells have not been sampled for two years. The December 1992 quarterly report shows that the upgradient well MW6 contains contamination. In several previous quarters no contamination had been detected upgradient. The downgradient wells have shown no contamination for several quarters. The FRP was submitted on 2 January 1992. In a letter to the County, dated 31 March 1992, I stated that the FRP was incomplete and lacked the following: 1 . Maps showing the complete extent of soil and ground water contamination; 2. A complete discussion and description of the proposed soil vapor extraction system including a proposal to investigate and remediate soil layers previously in contact with ground water; 3. A complete discussion of the ground water extraction, treatment, and preinjection systems, including the location of the extraction well (they proposed to use MW4 which is often dry during the summer months) , the results of additional aquifer testing required for reinjection, the location of the reinjection well , and the proposed injection rate; and 4 Acomplete report of rf waste discharge faceor discharge of treated ground water by to In a letter from the County to Geweke' dated 29 May 1992, County staff attached my memo and required submittal of the information listed in the memo, by 29 June 1992. We received a copy of Geweke' s addendum on 30 July 1992. The addendum provided some of the missing information but also reported the following: 1 . The "lateral extent of the vadose zone contamination has not been fully delineated. Therefore, we could not provide you with maps or figures depicting the extent of this contamination. One of the objectives of the FRP is to further assess the extent of the impacted soil . " ; 2. The downgradient extent of ground water contamination has not been fully defined, the samples, and they ucould ltant notpprovide hthe RBoard swith more not erecent ct ur ground water data; 3. The consultants were not aware that MW4 was dry during December 1991, therefore they proposed to install a new extraction well ; and 4. The consultants proposed using MW2 for reinjection. Regional Board Comments: 1 . As defined in the Tri-Regional Recommendations and Appendix A which were recommended for use at this site in the cover letter to the C&A, the extent of both soil and ground water contamination are to be defined and reortein cross eweke is out ofpcompliancehwith RtheoC&A alng wbecause ith sthe dPAR and sFRP� G remain incomplete. 2. At the time the addendum to the FRP was submitted, the down-gradient ground water monitoring wells did not contain detectable hydrocarbons and the consultant was not aware that MW4 was dry. Apparently, consultant did not have access to the quarterly reports.