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NAr. Jack Badey - 3 - 2 August 2010 <br /> In addition, US Environmental Protection Agency (EPA) and Interstate Technical and <br /> Regulatory Council (ITRC) guidance require source area and primary plume treatment before <br /> considering Monitored Natural Attenuation as a viable path to meeting cleanup objectives. <br /> Unifirst must implement a cleanup technology to reduce the mass of contaminant before the <br /> Central Valley Water Board can concur that monitored natural attenuation will meet cleanup <br /> objectives in a reasonable period of time. In addition to PCE in groundwater, there is also a <br /> mass of PCE in the vadose zone beneath the Unifirst structure that is contributing to PCE in <br /> groundwater. <br /> Unifirst needs to implement a remediation strategy that will reduce the bulk of the pollutant <br /> mass in the vadose zone and in groundwater. The Central Valley Water Board has adopted a <br /> General Order for Insitu Groundwater Remediation at Sites with Volatile Organic Compounds <br /> (Order No. R5-2008-0149). This General Order is designed to streamline the regulatory <br /> permitting process for implementing in situ biodegradation, in situ chemical oxidation, and <br /> recirculation of amendments to degrade PCE, TCE and other compounds from groundwater. <br /> If Unifirst wishes to apply for coverage under this General Order for a proposed insitu <br /> amendment, it should perform a bench test to verify that the proposed amendment will <br /> effectively remove the constituents of concern under the site conditions, and to identify specific <br /> geochemical alterations that would be likely to occur. <br /> Conclusion <br /> Central Valley Water Board concur with Unifirst that biodegradation is taking place. However, <br /> relying on intrinsic degradation will not result in the restoration of the groundwater to its <br /> beneficial uses in a reasonable amount of time given the existing mass of PCE and TCE that <br /> is present in unsaturated soil and in the groundwater plume downgradient of the former <br /> Parisian Industrial Laundry facility. Unifirst needs to provide a remediation proposal to reduce <br /> these constituents of concern in groundwater more quickly. <br /> By 29 October 2010 please provide a remedial action plan for groundwater remediation. If <br /> you have any, questions, you may contact me by telephone at (916) 464-4680, by email at <br /> atgrrell@wa#erboards.ca.gov, or by mail to the letterhead address. <br /> 1 r <br /> 1 ,1' <br /> , MY TER EL <br /> Private Sites Cleanup Unit <br /> cc: Mr. Michael Infurna, San Joaquin County Environmental Health Department, Stockton <br /> Mr. William Pipes, AMEC Geomatrix Consultants, Fresno <br />