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4 <br /> James L. Tjosvold, P.E. <br /> April 12, 1995 <br /> Page 2 <br /> On February 28, 1995, PG&E met with DTSC and the RWQCB to discuss the January, <br /> 1995 Technical Memorandum; PG&E's proposed remediation approach; and PG&E's <br /> requested modifications to the groundwater monitoring program. At the meeting, DTSC <br /> and the RWQCB verbally presented PG&E with their comments on the Technical <br /> Memorandum(which they later submitted in writing in a letter dated March 8, 1995). <br /> PG&E agreed to revise the Technical Memorandum to incorporate DTSC and RWQCB <br /> comments and submit a new Technical Memorandum by March 14, 1995. <br /> At the February 28, 1995 meeting, PG&E also briefly presented for discussion a <br /> preliminary remediation approach for this site. PG&E plans to incorporate this approach <br /> into the Feasibility Study. The approach includes remediation of soils with higher levels of <br /> contamination to eliminate them as potential sources of groundwater degradation and <br /> continuation of groundwater monitoring to demonstrate that natural groundwater <br /> attenuation is occurring. <br /> DTSC and the RWQCB both requested that PG&E fully delineate the extent of <br /> groundwater contamination as a prerequisite for the agencies' consideration of PG&E's <br /> proposed remediation approach. At the meeting, the following was agreed to as the steps <br /> that PG&E would take for the Feasibility Study: <br /> • Installation of additional A and B Zone groundwater monitoring wells to further <br /> define the groundwater plume, in particular, to delineate the nondetect <br /> groundwater contour and evaluate the potential for a vertical downward <br /> groundwater gradient. <br /> • Inclusion of remediation of soils with higher levels of contamination to eliminate <br /> them as potential sources to groundwater. <br /> • Inclusion of a range of groundwater treatment options in the feasibility study, from <br /> natural attenuation to pump and treat (and an evaluation of possible pump and <br /> treat options), including groundwater control as a remedial option in the event that <br /> natural attenuation is not effective. <br /> • Evaluation of historic land uses on neighboring parcels (e.g. at the neighboring Fire <br /> Station) and any historic pumping activity (to evaluate whether groundwater <br /> direction may have changed over time). <br /> PG&E will submit a Phase IV Groundwater Investigation Work Plan (identifying <br /> additional A and B Zone groundwater monitoring wells) to DTSC and the RWQCB. The <br /> purpose of the Phase IV Work Plan will be to identify well locations at the edge of the <br />