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Ms. Christine Johnston <br />Mountain Coal Company <br />Page 12 <br />August 23, 1996 <br />during the spring and summer of 1994 ranged from 16 mg/1 to 145 mg/1 for <br />iron, which is two to three orders of magnitude higher than the baseline <br />maximum. This is not within the range of baseline parameters. Well GP-1 <br />showed 16 mg%I iron on 05/18/94 and l09 mg/I iron on 08/31/94. Well SG-1 <br />showed 16 mg/I iron on 05/18/94 and on 08/31/94 showed 109 mg/I iron. <br />It is unlikely that two different wells sampled on the same dates showed the <br />exact same concentrations for iron. Nevertheless, the data clearly show that <br />iron concentrations are elevated in wells SG-1 and GP-1 both located <br />downgradient of the lower refuse pile. The Division recommends that these <br />data be checked with the laboratory analytical data sheets to ensure that the <br />data were accurately transcribed to the AHR report. <br />19. On page 1 of 6 of Table H-l in Appendix H of the 1994 AHR, the minimum <br />and maximum values for baseline concentrations are incorrect as compared <br />to previous AHRs. Specific conductivity, TSS, Fe, and Mn values presented <br />for both minimum and maximum baseline concentrations in the 1994 AHR <br />are different than those presented in the 1993 AHR (see Table E-3 of the <br />1993 AHR). With this type of inconsistency and data error it renders the data <br />set questionable as presented in the 1994 AHR. Again, this raises the issue <br />of providing the raw laboratory analytical data as an appendix to the AHR so <br />that data can be cross-checked. Please provide a revised report page <br />indicating the name of the laboratory used and where the actual laboratory <br />data sheets are filed in a revised report page. In future AHRs beginning in <br />1996 please provide laboratory analytical data in an appendix to the report. <br />20. The Division recommends adopting standard protocol for collection of <br />groundwater samples (refer to the last sentence on page 20 of the 1994 <br />AHR). EPA Region VIII protocol for groundwater sampling calls for filtering <br />the sample in the field prior to acidification for dissolved metals analyses, and <br />no filtration and acidification only for total metal analyses. Adopting a <br />standard protocol for sampling will facilitate more consistent results that will <br />aid in determining water quality trends. <br />21. The Division notes that some analyte concentrations in groundwater were <br />compared to secondary drinking water standards (refer to page 21). <br />Secondary drinking water standards are measured as dissolved concentration. <br />Secondary drinking water standards may not be the most appropriate <br />standards to apply to groundwater produced from the B Seam within the mine <br />site area. Established background levels may he more useful as groundwater <br />standards from which future comparisons can be made. The minimum and <br />