Laserfiche WebLink
December 30, 1994 • • <br /> Page 3 <br /> the maximum contaminant levels presented in A Compilation of Water Quality Goals <br /> (Marshack, 1993). The aforementioned concentrations constitute acceptable compound <br /> levels. <br /> Response Actions <br /> The general response actions necessary to achieve the soil and groundwater-based remedial <br /> objectives are: (1) monitor dissolved-phase plume movement, (2) develop and maintain <br /> institutional controls, and (3) reduce the mass of petroleum hydrocarbons in the capillary <br /> fringe and vadose zone, saturated soils, and groundwater. Response actions land 2 are <br /> elements common to each of the alternatives and are discussed below. Response action 3 is <br /> addressed in the Alternative Evaluation section. <br /> Elements Common to Alternatives <br /> Remediation Monitoring. Remediation monitoring is an aspect of the existing site <br /> remediation program, and will continue to be a key aspect of any remedial alternative. In <br /> addition to the current monitoring program, remediation monitoring will be performed to <br /> maintain compliance with any implementation permits, and to evaluate progress toward <br /> attaining the remedial objectives. Additionally, monitoring will be will be used as a tool to <br /> manage the dissolved hydrocarbon plume. <br /> Institutional Controls. This management technology will be used to reduce the possibility of <br /> exposure to petroleum hydrocarbon-affected media at, or from, the site. Generally, this is <br /> accomplished by restricting access to impacted media. Since impacted groundwater will <br /> persist for some time during remediation, use will be restricted by prohibiting installation of <br /> drinking water wells at, or near, the site. Additionally, groundwater pumping that may draw <br /> affected groundwater away from the site will be restricted. Site use restrictions may be <br /> imposed to ensure that the effectiveness of the recommended remedial alternative is not <br /> compromised. Specific restrictions will depend on the site use, but restrictions may include <br /> access restrictions, deed restrictions, zoning, or lease restrictions. Institutional controls <br /> achieve the remedial objectives by reducing exposure to all the media of concern. Finally, a <br /> migration control contingency plan will be prepared for implementation in the event specific <br /> triggers are activated (e.g. the location of the dissolved hydrocarbon plume edge). <br /> Remedial Alternatives <br /> Initially, the focus will concentrate on petroleum hydrocarbon mass removal. Alternatives <br /> were designed to mitigate nuisance conditions,reduce the risk of fire or explosion, and protect <br /> beneficial uses of water. The proposed alternatives are described below. <br /> • Alternative 1: Initially, use an intensive SVE program to remove <br /> petroleum hydrocarbon mass. Once petroleum hydrocarbon mass has been <br /> significantly diminished, use air sparging in conjunction with S VE to further <br /> 3 10001I b/wkpin <br />