SITE INFORMATION AND CORRESPONDENCE FILE 2

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George's Service August 2014 1600 West Durham Ferry Road, Tracy Claim No: 8475 Rationale for Closure under the Policy • General Criteria: The case does not meet all eight Policy general criteria. The case is not in the service area of a public water system. • Groundwater Specific Criteria: The case does not meet Policy criteria because the contaminant plume that exceeds water quality objectives is greater than 100 feet in length and the nearest water supply well is less than 250 feet from the Site. • Vapor Intrusion to Indoor Air: The case meets Policy Criterion 2a by Scenario 3b. The maximum benzene concentration in groundwater is less than 1,000 micrograms per liter (pg/L). The minimum depth to groundwater is greater than 10 feet, overlain by soil containing less than 100 milligrams per kilogram (mg/kg) of TPH. • 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. Approximately 500 cubic yards of impacted soil were excavated to a depth of 8 feet bgs and disposed offsite in July 2001. The Site is paved and accidental exposure to site soils is prevented. Objections to Closure and Responses According to the Path to Closure page in GeoTracker, finalized on May 22, 2014, the County opposes closure because: • Not in the service area of a public water system. RESPONSE: We concur. • Secondary source remains. RESPONSE: Secondary source as defined by the Policy was removed by excavation in 2001. • The case does not meet Policy groundwater criteria. RESPONSE: We concur. • The case does not meet Policy vapor criteria. RESPONSE: The case meets Policy Criterion 2a by Scenario 3b. • The case does not meet Policy direct contact criteria. RESPONSE: This case meets Policy Criterion 3b. Recommendation The Fund recommends that the County direct the responsible party to conduct targeted groundwater remediation in the vicinity of MW-2. KiA Larson, 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 2