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EPA Review <br /> "Well Monitoring Program <br /> Quarterly Monitoring Report <br /> First Quarter 2000 Sampling Round" <br /> dated May 2000 <br /> GENERAL COMMENTS <br /> 1. Table 3-7 lists thirty-eight instances in which the chemical <br /> concentration detected at a well during the first quarter 2000 <br /> has increased from a previous sampling event, indicating that <br /> chemical concentrations have not stabilized and that <br /> contaminants are migrating across the Site. However, the <br /> extraction wells and other components of the treatment systems <br /> are frequently not operational or malfunctioning. Since the <br /> treatment systems at the Site are not operating as designed, <br /> plume capture cannot be assumed. Therefore, please indicate how <br /> plume capture will be assured at the Site. <br /> 2. As shown in Table 3-1 (Page 3-2) , many of the extraction wells <br /> were not sampled because the pumps were not operating. In the <br /> Army's Response to Comments (RTC) to EPA's comment regarding <br /> the same table in the Draft 1999 Annual Monitoring Report (in <br /> that report it is Table 4.1-1 on Page 4-10) , it is stated that, <br /> "In most cases, the wells were not operating because of <br /> electrical circuitry problems, not mechanical problems with the <br /> pumps. Removing the headworks and pump to collect a sample is <br /> an effort that is outside the scope of the quarterly sampling. <br /> Furthermore, if the extraction wells are not operating during a <br /> quarter, sampling is not required." Since pump failure appears <br /> to be a continuing problem and non-operational extraction wells <br /> do not have to be sampled, the remedy may not be fully <br /> operational and adequately monitored. In order to better <br /> evaluate the remedy for the Site, please include a section in <br /> the Report that discusses extraction system improvements and <br /> provides a treatment system effectiveness evaluation. Please <br /> include an evaluation of how the pump failure affects the <br /> treatment system capture zones and contaminant migration and <br /> state how problems with the treatment system will be corrected. <br /> 3. There are numerous discrepancies between the Draft 1999 Annual <br /> Monitoring Report Table 6.4-1 (Preliminary Recommendations for <br /> Sampling Frequencies, 2000 Groundwater Monitoring Program, <br /> DDJC-Tracy) and Appendix A of the Report (Summary of Analyses <br /> Performed) . These discrepancies are not listed on Table 3-1 <br /> (Wells Not Sampled According to the 2000 Well Monitoring <br /> Program Field Work Plan) in the Report. It is assumed that <br /> Table 3-1 includes all instances where the current sampling <br /> 1 <br />