SITE INFORMATION AND CORRESPONDENCE 1995-2004

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Ms. Frances E. Anderson Page 3 investigative fieldwork remaining should proceed as scheduled to provide additional information necessary to evaluate a cleanup to background alternative in the Feasibility Study." That investigative work pertained solely to groundwater, and was the subject of the Phase III Groundwater Investigation Workplan submitted to your agency on July 16, 1993, modified by letter addendum dated July 28, 1993, and approved by DTSC on August 18, 1993. Yet despite the remedial investigation approval (as it pertains to soil investigations in Area I), we continue to receive comments from the DTSC and RWQCB which question the adequacy of soil characterization in Area I. RWQCB comments in their letter dated April 6, 1995 contained a request that PG&E develop isoconcentration maps of soil contamination in Zones A, B and C to"identify data gaps". The perceived lack of characterization in areas critical to source area definition was the subject of several agency comments during our meeting of May 22, 1996, and most recently, in RWQCB comments dated July 2, 1996 on the Phase IV Groundwater Investigation Report, in which it is pointed out that the State has not"...agreed to allow no further definition in non-source areas". By dismantling the double negative, it becomes reasonable to assume that the State (in this case, the RWQCB) may require further characterization of soils in Area I. PG&E thus is led to question not only the validity of the October 21, 1993 approval, but also the timing of the RWQCB comments, given that at the time those comments were prepared,the RWQCB had been in possession of the data now being deemed incomplete for nearly three years. Our uncertainty regarding your expectations is not diminished by the language of your July 2 letter, which correctly points out that"...PG&E must ensure that the nature and extent of all releases or threatened releases of a hazardous substance are thoroughly investigated." The letter then describes in subjective fashion such an investigation: "...a thorough investigation would consist of..." and"characterization to background levels would be required...". It is unclear whether such references are meant to indicate that investigation is not complete; if this is so, your letter gives no clue as to what portion of the investigation bears supplementing. DTSC's July 9, 1996 comments on the draft Phase IV Groundwater Investigation Report emphasize the necessity to address data gaps, but beyond reference to the newly discovered material in Area II, no explanation of what those gaps may be is given. All of this points to the critical need to examine each area of the site with the intention of agreeing (among PG&E,DTSC and the RWQCB) where investigation to define the extent of hazardous substances is complete, and where it must be supplemented by additional investigation--for soils and for each of the defined groundwater zones. The recent discovery by PG&E of potential source areas in Area II of the site only adds to this imperative.