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Review of the Draft Well Monitoring Program 2005 <br /> Annual Monitoring Report <br /> DDJC Tracy Site <br /> December 2005 <br /> GENERAL COMMENT <br /> 1. Monitoring well LM178AU was installed in February 2002 as part of the remedy at <br /> SWMU 8, but it is not listed with the other SWMU 8 wells in any of the site-specific <br /> tables. It is located between LM019A and LM119A, both of which are listed with <br /> SWMU 8. Please add LM178AU to all tables that list wells associated with SWMU 8. <br /> SPECIFIC COMMENTS <br /> 1. Section 4.6.1 Petroleum Hydrocarbons, Subsection 4.6.1.5, Page 4-8: The <br /> recommendation of no further sampling for total petroleum hydrocarbon in the diesel and <br /> gasoline range (TPH D and G) at extraction wells needs further justification for TPHG. It <br /> is stated that TPHD has not been detected in more than two years at any extraction wells; <br /> however, there is no information about when TPHG was last detected. Please revise the <br /> text stating when TPHG was last detected to justify the recommendation for no further <br /> sampling of THPG at extraction wells. <br /> 2. Section 4.7.6 PW003,Page 4-9: It appears that the text has the incorrect maximum <br /> contaminant level (MCL) for chloroform. This section states that the MCL for <br /> chloroform is 100 micrograms per liter(ug/L),however, the federal MCL for chloroform <br /> is 80 ug/L, as shown in Table 4.7-1 on page 4-24. Please revise the text with the correct <br /> MCL for chloroform. <br /> 3. Section 4.8.4, Page 4-11 and Table 4.1-2, Maximum Concentrations Reported in <br /> 4Q04—3Q05 Samples Compared to Water Quality Standards, Page 4-14: The text <br /> states that bis(2-ethylhexyl)phthalate was detected above water quality objectives in <br /> LM168AU at SWMU 8,but the table shows that LM178AU (also at SWMU 8 <br /> approximately 200 feet northeast of LM168AU)had a bis(2ethylhexyl)phthalate 1� <br /> concentration of 28 ug/L, the highest concentration at the DDJC-Tracy facility in 3Q05. <br /> Please add discussion of bis(2-ethylhexyl)phthalate in LM178AU to the text. In addition, <br /> EPA has made repeated comments that groundwater samples collected near landfills are a <br /> likely exception to the general statement regarding phthalates as a common laboratory <br /> contaminant due to the presence of plastic materials in the landfill (note that it is listed as <br /> a contaminant of concern for SWMU 8 in Table 4.2-1). Given the occurrence ofbis(2- <br /> ethylhexyl)phthalate at seven times the MCL,please delete the statement from this <br /> paragraph dismissing bis(2-ethylhexyl)phthalate as "probably not present in <br /> groundwater", at least for SVIMU 8. <br /> 1 <br />