ARCHIVED REPORTS_XR0003771 - Laserfiche WebLink

Home Browse Search

_ L I I I 15 February 2000 AGE-NC Project No 98-0448 Page 32 of 33 I with soil vapor extraction) described an this CAP could be effective to remediate the site In-situ bioremediation or natural attenuation of ground water may not be the most cost-effective or feasible remedial alternatives at the site due to laboratory analysis of ground water and soil samples that suggested little, if any at all, bioremediation has taken place over the last 20 years Although the ' laboratory indicated that necessary baonutnents and physicochemical characteristics were adequate at the site to sustain microbial growth,the laboratory also indicated the lack of selected hydrocarbon- degrading macro-organisms was probably due to an alternative food sources existing in the native soil and ground water(a a organic debris) Petroleum hydrocarbon-impacted ground water appears to be limited to the area containing wells EW-1, MW-1, MW-2,MW-4 and MW-6 Impacted ground water at the site has an estimated north- south diameter of approximately 90 feet, an east-west diameter of 55 feet and appears to extend downward to a depth of approximately 50 bsg (See Figures 7, 8 and 10) The greatest concentrations of impacted soil is present in the area bound by wells MW-1, MW-2, MW-4 and EW-I iRemediation of impacted ground water in the"core"area should be conducted concurrently with soil remediation to prevent re-contamination of remedlated soil In-situ air spargang/vapor extraction appears to be a viable alternative for remediation of both soil and ground water in the vicinity of the µ former UST location The system used for soil vapor extraction could also be used for the air spargang/extractaon system Combined with SVE, IAS should mechanically strip hydrocarbons without the addition of any chemicals or microbe solution into the environment It Is a well known and widely accepted method ' of volatilizing hydrocarbons As IAS has few, if any, adverse environmental effects, it is likely to be more readily approved for implementation by regulatory agencies A 12-to 24-month remediation period can be expected to reduce concentrations to a level suitable for closure consideration Ground ' water remediation alternatives, estimated durations and associated costs for the site are summarized on Table 11 ' In summary, AGE recommends the following actions for remediation of hydrocarbon-impacted ground water atthe site ' I Preparation of a RAWP detailing the proposed installation and operation of the IAS system This work plan should include the installation of spargang points and extraction-wells ' 2 Installation of a compressor or blower-dnven IAS system at the site concurrently with the proposed SVE system ' 3 Aar should be supplied to IAS points via underground piping from an IAS unit capable of approximately 10 to 15 psi at a rate of 2 to 5 scfm Advanced GeoEnviron mental,Inc 1 '