ARCHIVED REPORTS_XR0011160 - Laserfiche WebLink

Home Browse Search

CAMBRIA • Table 1 Site Conceptual Model,Shell-branded Service Station,2494 East Fremont Street,Stockton,California 3 1 Remediation Status 31 Remedial Actions Taken During the 1996 tank removal activities, approximately 15 cubic yards of soil were overexcavated from the UST pit, and 20 cubic yards of soil were overexcavated from the northwestern dispenser island Interim remedial measures were conducted in March/April 2004 Groundwater was extracted from wells S-1 and S-1-85 over a period of 10 days in an attempt to reduce 1,2-DCA concentrations A total of approximately 6,672 gallons of water were removed during this remediation effort 3 2 Area Remediated Overexcavation was performed in the areas beneath the former USTs and dispensers Interim groundwater extraction was performed in wells 1 and S-1-85 3 3 Remediation Effectiveness It is unknown how effective the overexcavation activities were The interim groundwater extraction activities removed an estimated 1 88 pounds of TPHg, 010 pounds of benzene, and 0 02 pounds of 1,2-DCA Ongoing evaluation of 1,2-DCA concentrations will be performed to determine the effectiveness of this interim remedial measure 4 Well and Sensitive Receptor Sure 41 Designated Beneficial Water Existing and potential beneficial uses include municipal and domestic . Use water supply, agricultural supply, industrial service supply, and industrial process supply(CVRWQCB Basin Plan) 4 2 Shallow Groundwater Use A well survey conducted by Cambria in 2001 did not identify wells screened in shallow groundwater within a 2,000 foot radius of the site 4 3 Deep Groundwater Use A well survey conducted by Cambria in 2001 identified three water supply wells within a 2,000 foot radius of the site The closest well,which is located approximately 600 feet southeast of the subject site, is screened from 165 to 176 fbg 4 4 Well Survey Results A well survey conducted by Cambria in 2001 identified three water supply wells within a 2,000 foot radius of the site The closest well,which is located approximately 600 feet southeast of the subject site, is screened from 165 to 176 fbg A second well was identified that is 900 feet south of the site, and the third well is located approximately 1,950 feet west of the site 4 5 Likelihood of Impact to Wells It is unlikely TPHg and BTEX have impacted water supply wells due to the limited extent of their plumes 1,2-DCA concentrations show significant attenuation between the suspected source area and the southeast corner of the site, which suggest the plume likely does not extend very far to the southeast The private well located 600 feet southeast of the site has been sampled (8120103) and it did not contain TPHg, BTEX, lead scavengers, or any of the 7 fuel oxygenates 46 Likelihood of Impact to Surface Impact of surface waters due to the release at the subject site is highly Water unlikely due to the fact that groundwater occurs at 46 fbg or greater Na surface water bodies have been identified in the vicinity of the site i 0955 Page 4 of 5 Date Modified 12/16/2004