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WF� <br /> ver City Petroleum 3 - 29 January 2008 <br /> onnell Motor Lift Truck <br /> ockton, San Joaquin County <br /> $110,000, although the CAP suggests using monitoring wells as injection points to <br /> reduce costs. <br /> The CAP also recommends continuing the SVE/AS in soil and shallow groundwater, with an <br /> expansion of the SVE/AS system under the tire warehouse (Figure 12) to address the lateral <br /> extent of the shallow groundwater plume and soil contamination; and the removal of the <br /> current SVE internal combustion (natural gas powered) vapor treatment unit, with replacement <br /> by a more cost effective granulated activated carbon treatment unit. <br /> 10 January 2008 Meeting <br /> At your request, Regional Board staff met with you and your consultant AGE at the site, to <br /> discuss the CAP and provide direction to you. You expressed concerns with the amount of <br /> remaining State Water Resources Control Board UST Cleanup Funds. Regional Board staff <br /> were concerned that the cost for ISCR was underestimated, due to the complexity of the <br /> injection delivery system and our experience that shows the reductive dechlorinization process <br /> is extremely slow even when a treatment compound is effectively injected. Pilot studies of a <br /> year or longer are not uncommon. Staff asked for additional case studies to support the ISCR <br /> proposal, and received a response by email from AGE. I reviewed those cases studies, as <br /> well as additional similar case studies found on the Internet. Although I have concerns that <br /> the time frame for complete remediation may, after initial inoculation, be on the order of <br /> decades, and the delivery of the HRCTM may be problematic due to the contaminant depths <br /> (80 to 120 feet bgs) in fine sediments, I recognize that remediation options for the deeper <br /> plume are limited or not cost effective. The deeper groundwater plume is well characterized in <br /> all directions except to the south, while monitoring shows the deeper plume does not exhibit a <br /> declining concentrations trend to the south and east at this time, making MNA questionable as <br /> a remedial option. At the meeting we agreed to conduct a pilot study for ISCR, due to the <br /> extensive monitoring well network that will provide adequate data sample points to track the <br /> progress of the pilot study. If ISCR is found effective at reducing concentrations and not <br /> detrimental long-term to water quality during the pilot study, we will concur to the full-scale <br /> ISCR remediation of the deeper aquifer. We also concurred with the proposed expansion of <br /> the current SVE/AS system for soil and shallow groundwater remediation, as this is a cost <br /> effective and proven technology. Additionally, we requested that the pilot study report include <br /> a comparison of the current MNA concentration trend with a trend for the active ISCR <br /> remediation, to determine the effectiveness of the ISCR treatment versus MNA and to <br /> estimate when water quality objectives would be met. <br /> Comments <br /> The following CAP submittals are necessary and appropriate for the remediation of petroleum <br /> hydrocarbons in soil and groundwater at your site. <br /> 1) A workplan to expand the current SVE/AS system is due 11 April 2008. Installation <br /> and operation of the expanded SVE/AS system will be accomplished no later than <br /> 1 July 2008. A report of the installation of the upgrades to the SVE/AS system is due <br /> 1 September 2008. <br />