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-+ I <br /> 0 a <br /> Review of the Draft Well Monitoring Program <br /> 2006 Annual Monitoring Report <br /> DDJC-Tracy Site,Tracy, California <br /> January 2007 <br /> GENERAL COMMENT <br /> 1. It would be useful to include a table containing dieldrin concentrations exceeding Aquifer <br /> Cleanup Levels (ACLS) for fourth quarter of 2005 (4Q05) and 3Q06, similar to Table <br /> 3.2-4, which contains this information for trichloroethene(TCE) and tetrachloroethane <br /> (PCE). <br /> SPECIFIC COMMENTS <br /> 1. Section 1.0, Introduction, Page 1-1: Itis not clear from the Introduction why the Draft <br /> Well Monitoring Program 2006 Annual Monitoring Report, DDJC-Tracy(Annual <br /> Report) only summarizes the results of two quarters (4Q05 and 3Q06) and not four <br /> quarters.of groundwater monitoring events as seen in past annual reports. It is stated in <br /> Section 2.1 that groundwater elevation data for the annual report was only collected in <br /> 4Q05 and 3Q06 due to funding constraints. Section 3.1.1 states that the 1Q06 and 2Q06 <br /> sampling events were not performed due to contractual and funding constraints. <br /> However, it appears the Annual Report would be more user friendly if this was discussed <br /> earlier. The same clarification could be added to the Executive Summary on page ES-1 <br /> and the Introduction. In addition, it is not stated in the text if any wells were not sampled <br /> as a result of the cancellation of the 1 Q06 and 2Q06 sampling events. Please clarify in <br /> the Introduction and Executive Summary why only two and not four quarters are <br /> summarized in this Annual Report and briefly state in the text if any wells were not <br /> sampled at all in the past year due to the cancellation of the 1Q06 and 2Q06 sampling <br /> events. <br /> 2. Table 3.2-3, Maximum Concentrations Reported in 4Q05 and 3Q06 Samples <br /> Compared to Water Quality Standards,DDJC-Tracy: The maximum dieldrin <br /> concentration reported listed in Table 3.2-3 is 0:180 micrograms per liter(ug/L) J in well <br /> LM106A. However, the field duplicate from this well during the 3Q06 sampling event <br /> had a concentration of 0.190 ug/L J dieldrin. When a field duplicate sample contains a <br /> different concentration than the original sample, the higher concentration of the two <br /> should be used. This practice was employed when evaluating TCE data(see Table 3.2-4 <br /> and the TCE concentration data for well LM06713). For consistency, please change the <br /> maximum dieldrin concentration in Table 3.2-3 and Table 3.3-1 (and elsewhere in this <br /> report, if applicable) to 0.190 ug/L J. <br /> 3. Figure 3.3-1,Dieldrin Reported in the Upper Hydrologic Zone Fourth Quarter 2005 <br /> and Third Quarter 2006: Extraction well EW009B appears to be a Middle Hydrologic <br /> Zone Well and appears to have been placed on Figure 3.3-1 in error. Please remove well <br /> 1 <br />