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hydrogeologist's interpretation. However, there is no criteria for the placement <br /> of the monitoring wells. It is recommended that siting criteria be developed <br /> within the Ground Water Model Report to assist the field geologist in siting and <br /> screening the monitoring wells. The criteria should include: <br /> A) To monitor water levels and water quality downgradient and upgradient <br /> of the extraction wells. <br /> B) To monitor water levels and water quality within the permeable zone <br /> screened by the extraction wells, and within overlying and underlying <br /> zones. <br /> C) To verify that the capture zones of individual extraction wells <br /> overlap (i .e. , no gaps exist) . <br /> D) To determine hydrological and geological parameters of the ground <br /> water regime in order to adequately calibrate the ground water <br /> contaminant transport model . <br /> E) To monitor water levels and water quality around the storm pond and <br /> injection wells to determine if the discharge of treated ground water <br /> in these areas significantly affect ground water contamination <br /> migration patterns. <br /> F) To utilize the data collected by the above monitoring network to <br /> operate the ground water extraction system in the most effective <br /> manner. <br /> 3) A typical extraction well detail should be provided. <br /> 4) Section 3.2.2.4 discuses the type of liquid level controller within the <br /> extraction wells. Allowing the extraction pumps to run dry before shutting off <br /> the pump could significantly reduce the useful life of the pump, due to <br /> overheating (especially on water cooled pumps) , and cavitation effects. It is <br /> recommended that the liquid level control be achieved by a method that would not <br /> allow the pump to run dry, possibly incorporating water level /pressure sensors <br /> and transducers within the proposed water level sampling tubes (Section 3.2.2.7) . <br /> 5) A liquid level controller should be installed within the storm pond to ensure <br /> that overflows do not occur and that, during the winter months, there is <br /> sufficient capacity for the containment of the Depot's storm water runoff. <br /> 6) The water quality sampling strategy during start-up and prove-out appear <br /> sufficient, however during the operational phase of the system weekly sampling <br /> of the treatment plant' s influent and effluent for EPA 601 and 602 compounds will <br /> be required. In addition, monthly sampling of all extraction wells, injection <br /> wells, and monitoring wells for EPA 601 and 602 compounds and EPA's Safe Drinking <br /> Water Act primary and secondary drinking water parameters will be required. The <br /> NPDES permit's monitoring program will likely contain these monitoring <br /> requirements. <br /> 7) Section 3.9 discusses the automatic operation of the interim ground water system. <br /> The approach is to run the plant unat.teneed except for one 3-hour period each <br /> week. If a particular unit fails, the system is shut down and the contractor, <br /> 2 <br />