SITE INFORMATION AND CORRESPONDENCE

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Super Center Mart April 2014 701 East Charter Way, Stockton Claim No: 12741 Water Service. The affected groundwater is not currently being used as a source of drinking water, and it is highly unlikely that the affected groundwater will be used as a source of drinking water in the foreseeable future. Other designated beneficial uses of impacted groundwater are not threatened, and it is highly unlikely that they will be, considering these factors in the context of the site setting. Remaining petroleum hydrocarbon constituents are limited and stable, and concentrations are decreasing. Corrective actions have been implemented and additional corrective actions are not necessary. Any remaining petroleum hydrocarbon constituents do not pose a significant risk to human health, safety or the environment. Rationale for Closure under the Policy • General Criteria: The case meets all eight Policy general criteria. • Groundwater Specific Criteria: The case meets Policy Criterion 1 by Class 2. The contaminant plume that exceeds water quality objectives is less than 250 feet in length. There is no free product. The nearest water supply well or surface water body is greater than 1,000 feet from the defined plume boundary. The dissolved concentration of benzene is less than 3,000 micrograms per liter(Ng/L), and the dissolved concentration of methyl tert-butyl ether(MTBE) is less than 1,000 pg/L. • Vapor Intrusion to Indoor Air The case meets the Policy Exclusion for Active Station. Soil vapor evaluation is not required because the Site is an active commercial petroleum fueling facility. • Direct Contact and Outdoor Air Exposure: This case meets Policy Criterion 3b. Although no document titled "Risk Assessment' was found in the files reviewed, a professional assessment of site-specific risk from exposure through the direct exposure pathway was performed by Fund staff. The assessment of site-specific risk from potential exposure to residual soil contamination found that maximum concentrations of petroleum constituents remaining in soil will have no significant risk of adversely affecting human health. The Site is paved and accidental exposure to site soils is prevented. As an active petroleum fueling facility, any construction worker working at the Site will be prepared for exposure in their normal daily work. Objections to Closure and Responses According to a January 22, 2014 letter, the County recommends that two additional rounds of groundwater monitoring be conducted to confirm the groundwater plume is stable following the ceasation of active remediation: RESPONSE: We concur. Recommendation The Fund concurs with the County that two additional rounds of groundwater monitoring should be conducted by the Responsible Party following the ceasation of active remediation. Z ' Kirk arson, P.G. Date Robert Trommer, C.H.G. Date Engineering Geologist Senior Engineering Geologist Technical Review Unit Chief, Technical Review Unit (916) 341-5663 (916) 341-5684 Page 2 of 13