SR2501037 (2) - Laserfiche WebLink

Home Browse Search

Addendum to Proposed Remediation Well Installation Work Plan Stockton Charter Way Commingled Plume #CP0057 May 2, 2025 • Former Chevron facility #92033, located at 508 West Charter Way in Stockton, • Former ARCO (ARC) service station no. 2168, located at 441 West Charter Way in Stockton, • Former Texaco (Equilon), located at 440 West Charter Way in Stockton, and, • Former Colombo/Toscana Bakery (Sara Lee; now BBU), located at 1444 South Lincoln Street in Stockton. In April 2010, the CRWQCB-CVR classified the Site as a commingled plume and since then, the JC have been working cooperatively to address environmental cases. In 2003, the City of Stockton changed the name of a portion of West Charter Way to Dr. Martin Luther King Jr. Boulevard. For reporting purposes, the Site has continued to be referred to as the Stockton Charter Way Commingled Plume Site and the historical Charter Way addresses are used. 1.2 CURRENT STATUS In a letter dated November 7, 2024 (Appendix A), the CRWQCB-CVR requested a meeting to discuss remedial options for two separate areas of the Site where residual concentrations remain over California Low Threat Closure Policy (LTCP) criteria. In the letter,the CRWQCB-CVR noted that Phase I Air Sparge (AS) and Soil vapor Extraction (SVE) have been effective in the former Bimbo Bakeries USA (BBU) area of well SLUE-1 and the Accelerated Remediation Technology (ART) wells installed to remediate benzene, toluene, ethylbenzene, and xylenes (collectively BTEX) and methyl tert-butyl ether(MTBE) in groundwater primarily associated with the former Texaco property have been effective at significantly reducing chemical concentrations in the areas and depths where the wells were designed to address. LTCP criteria have been reached in groundwater areas across the Site that require active remediation apart from the two areas noted. Per November 7, 2024, directive, Stantec submitted a Proposed Remediation Well Installation Work Plan dated February 24, 2025. The CRWQCB-CVR reviewed the Work Plan and requested a brief Work Plan Addendum in a letter dated March 6, 2025 (Appendix A). Per the March 6,2025,directive,this document is presented to propose additional remedial action to achieve groundwater remediation goals. With regulatory and JC approval, Stantec proposes additional remedial measures via an additional ART well installation to address deeper residual MTBE in well SMW-10-1 17. Per the CRWQCB-CVR directive, the following sections present a Work Plan Addendum to describe and detail the additional proposed scope of work. For reference, Figure 1 presents a Site Location Map and Figure 2 presents a Site Plan with Proposed ART Well Locations. A figure showing the current and proposed ART remediation wells and piping layout is provided as Figure 3. Proposed Soil Boring and Well Construction Details are summarized in Table 1. Regulatory correspondence is provided in Appendix A. 2.0 ADDITIONAL PROPOSED ART WELL INSTALLATION in accordance with the CRWQCB-CVR letter (Appendix A), one additional ART well is proposed to further assist in remediating residual MTBE in deeper groundwater beneath the Site to meet 5 Stantec 2