SITE INFORMATION AND CORRESPONDENCE 1995-2004

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James L. Tjosvold,P.E. July 24, 1996 Page 3 On May 22, 1996, a meeting between PG&E,DTSC and the RWQCB was conducted to discuss remedial objectives and goals for groundwater; the conceptual model of how constituents migrated to groundwater in the past; modeling results for evaluating current conditions and how long it takes for COPCs to migrate to groundwater; and treatability results for in-situ soil stabilization. The conceptual model was agreed on and further sensitivity analysis work was discussed with respect to the VLEACH model. The treatability study indicated mixed results for stabilization of the source area soils. At the meeting, it was recommended that the soil and groundwater feasibility studies be combined into one feasibility study and that a range of groundwater goals and points of compliance be used to evaluate the technologies in the combined feasibility study. This understanding was set forth in a June 6, 1996 letter submitted to DTSC by PG&E. In a July 2, 1996 letter,DTSC clarified that background or non-detect groundwater quality (where economically and technically feasible) is the starting point for evaluating alternatives in the feasibility study. The"Phase IV Groundwater Investigation Draft Report" describing the installation of six new groundwater monitoring wells at the site was submitted for DTSC and RWQCB review on June 11, 1996. On June 24, 1996, a conference call was conducted to review the results of the Phase IV groundwater investigation. PG&E also presented the proposed remedial objectives and goals for soils and groundwater and the proposed points of compliance to be used in the feasibility study during this conference call. Agency comments on the Phase IV Groundwater Investigation Draft Report were received by PG&E on July 9, 1996. PG&E will address these comments by letter addendum, rather than submitting a revised Phase IV report. The results of quarterly groundwater monitoring done in June, 1996 will be submitted to the agencies by July 31, 1996 in the"Quarterly Monitoring Report, PG&E Stockton Former MGP Site, Second Quarter 1996". The next quarterly groundwater monitoring will be conducted in September, 1996. III. Schedule Changes: During the May 22, 1996 meeting PG&E agreed to recombine the soil and groundwater into one feasibility study. Because of this, an updated project schedule incorporating a combined soil and groundwater feasibility study which evaluates a range of groundwater goals and points of compliance was submitted to DTSC on June 6, 1996. Periodic joint agency/PG&E meetings are also included in the schedule.