ARCHIVED REPORTS_XR0013021 - Laserfiche WebLink

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Ultramar/former Beacon #12474 page 2 3440 E. Main St., Stockton. Additionally, the occurrence of 1,2-DCA (reported as EDC) is not well monitored or characterized at this site. The last groundwater-sampling event that analyzed for 1,2 DCA was on June 27 2001 and detected 240 ugll in the deepest well, "MW-12", and 370 ug/1 in the shallower, 'wet', vapor well, "VW-4". Based on the comments noted above, EHD cannot accept the PAR and the site investigation phase is not complete. Further investigation is required to define the extent of petroleum contamination. E The Corrective Action Plan (CAP) portion of ,,h`s combination report listed multiple alternatives for both soil and groundwater remediation. In considering possible alternatives for soil remediation, this report listed soil vapor extraction (SVE), over-excavation, and passive remediation. As EHD has stated in recent correspondence regarding another ULTRAMAR site (Beacon #419, EHD letter dated 4-23-02) with a PAR/CAP submittal in San ,Joaquin County, it is the purpose of the 'feasibility' portion of the CAP to evaluate the cost-effectiveness, viability, and actual feasibility of each alternative. Site- io.� specific data is required for each alternative evaluated in order to successfully conclude that a remedial alternative is feasible. The CAP did not include a full evaluation, including costs and time allotment estimates for each of the remedial alternatives listed. With 'aver-excavation' as an example, a discussion should have included the method of soil removal, the calculated amount of soil to be removed, storage and disposition of the soil, a time requirement for the start-to-finish process, cost estimates, and a discussion of the 'down-time' for the currently active gas station located at this site. SVE was the only alternative discussed beyond the general principles involved for each alternative, and still did not include costs or duration. However, EHD questions the validity of even including 'over-excavation' as a remedial alternative for this site. Over-excavation at an active, pumping, gas service station, owned by others, and at a site with contamination deep in the saturated zone (>80' bgs) cannot be considered a feasible option for this site. Additionally, listing 'passive remediation' as a feasible remedial alternative for a site with elevated levels of fuel contaminants stili present after ten years of investigation may not be relevant, except as a follow-up technique after completion of an active remediation. Remedial alternatives for groundwater corrective actions included air sparging, above ground treatment (groundwater extraction?), in-situ bio, and passive remediation and also did not include site-specific field tested data or estimates of cost or time requirements.