Laserfiche WebLink
ENV,o RECEIVECI <br /> A M E R I CA � <br /> 244 California Street,Suite 500 SEP 2 9 2004 <br /> San Francisco,CA 94111 <br /> (415)989-9933 ENVIRONMENI-HEALTH <br /> Fax(415)989-9934 PERMIT/SERVICES <br /> w envannerica.com <br /> September 24, 2004 <br /> Mr. Duane White <br /> Department of Toxic Substances Control <br /> 8800 Cal Center Drive <br /> Sacramento, California 95826-3200 <br /> RE: Response to September 7, 2004, DTSC Letter <br /> Former Manufactured Gas Plant Site <br /> Stockton, California <br /> Dear Mr. White: <br /> ENV America Incorporated (ENV America) has prepared this letter on behalf of Pacific Gas <br /> and Electric Company (PG&E) for the former manufactured gas plant (MGP) site (Site) <br /> located in Stockton, California. This letter has been prepared in response to a September <br /> 7, 2004, letter from the California Department of Toxic Substances Control (DTSC) to <br /> PG&E. <br /> BACKGROUND <br /> ENV America recently prepared two reports' for the Site on behalf of PG&E and submitted <br /> to the DTSC. Evaluations in the two reports conclude that natural attenuation (NA) of <br /> constituents of concern (CDCs) in groundwater is occurring at the Site. Based on the <br /> evaluations, site closure was requested from the DTSC. DTSC reviewed the reports and <br /> provided comments in a September 7, 2004, letter to PG&E indicating that: <br /> 1. The groundwater monitoring program for the Site cannot be terminated until the <br /> remedial action objectives (RAOs) are met. The RAOs were discussed in the <br /> March 1998 Final Remedial Action Plan (RAP; prepared by CH2M Hill). <br /> 2. Proposed modification to the groundwater monitoring program needs to be <br /> supported by an evaluation using the Groundwater Monitoring Decision Tree <br /> included in the Final RAP. <br /> ENV America and PG&E responses to these two DTSC comments are described in the <br /> following sections. In summary, even though COC concentrations in some of the <br /> groundwater samples collected from the Site exceed the numerical RAOs, the Site can be <br /> ENV America Incorporated, June 2004, Analysis of Groundwater Monitored Natural Attenuation. <br /> ENV America Incorporated, July 2004, 2004 Semiannual Groundwater Monitoring Report, First and <br /> Second Quarter. <br />