Laserfiche WebLink
determining the changes in concentrations of electron acceptors and associated metabolic <br /> products, one can determine the corresponding mass of contaminant that is biodegraded. <br /> P P g g <br /> i <br /> Appendix D contains a recent article entitled "Geochemical. Indicators of Intrinsic <br /> Bioremediation' that explains the parameters monitored in the intrinsic remediation <br /> demonstration for a gasoline-contaminated aquifer near Rocky Point, North Carolina. <br /> Appendix D also contains a description of the minimal aeration sampling protocol that is <br /> required for demonstrating intrinsic bioremediation. <br /> Intrinsic Bioremediation Demonstration Component <br /> The intrinsic bioremediation demonstration will include specialized sampling, data <br /> evaluation, and fate and transport modeling, as follows. <br /> Baseline Minimal Aeration Sampling. Samples will be collected by minimal aeration <br /> technique for four consecutive quarters to develop a statistically significant baseline. 2._l ,I <br /> Conventional groundwater monitoring will continue for wells not sampled by minimal <br /> .... <br /> aeration technique. <br /> Data Evaluation. Baseline data will be evaluated for indicators of biodegradation, rate- <br /> limiting concentrations of electron acceptors and nutrients, and constituent-removal trends. <br /> { Fate and Transport Model. A contaminant fate and transport model will be developed and <br /> calibrated to historical data. Compliance monitoring points will be identified that are beyond C6 <br /> the extent of migration potential as determined by fate and transport modeling. <br /> Long-Term Monitoring and Contingency Plan <br /> Long-term monitoring and reporting will.occur until data indicate that the site may be clean <br /> enough to seek closure. A set of criteria will be established that will initiate a contingency <br /> plan if (1) the plume migrates beyond the compliance monitoring points, (2) constituent <br /> concentrations are not degrading at a satisfactory rate, or (3) the risk to human health <br /> increases significantly. The contingency plan will consist of aggressive remediation <br /> intervention that may require augmenting the natural rate of contaminant removal and/or <br /> j creating an inward hydraulic gradient by pumping. <br /> Option B: Pumping With Aboveground Treatment <br /> Option B for plume remediation consists of groundwater pumping with the following <br /> additional components: <br /> • Continued operation of the AS/SVE system for source removal <br /> • On-site treatment of extracted groundwater by air stripping/vapor phase GAC <br /> i <br /> iSF010030983.DOC 4-5 <br />