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damage suspect levels at Trapper for 1996, except for those parameters which, historically, have <br />a high background reading, which include TDS and specific conductance. <br />9. On page 5-3 of the annual report, it is stated that all of the NPDES water quality <br />exceedences have been addressed and justified in letters to the Colorado Department of <br />Health. The Division has those reports on file. However, the Division believes that, for <br />the sake of clarity, those exceedences, and their justifications, should be summarized in <br />the annual report. Please comment. <br />0. For the surface water data, as well as the groundwater data, please add footnotes <br />explaining the abbreviations used in the tables. <br />11. On page 5-3 of the annual report, it is stated that pH values reached a high of 8.9. <br />However, in July of 1996, for NPDES site 001, there were pH readings of 9.3., 9.5 and <br />9.4 for the sampling times of 7/2196, 7/8/96 and 7/9/96. Please modify page 5-3 to reflect <br />this. The Division understands that these readings were still in compliance for NPDES <br />001. <br />12. It appeazs that, for surface water monitoring and for ground water monitoring, the <br />laboratory detection limit for lead changed from .020 mg/1 to .050 mg/I in 1994. Please <br />explain <br />Groundwater <br />In order to determine whether groundwater was being adversely affected by mining operations, <br />and whether suspect levels were being exceeded, the results of the groundwater sampling <br />program were compazed with material damage suspect levels as obtained from "A Description of <br />the Material Damage Assessment Process Pertaining to Alluvial Valley Floors, Surface Water, <br />Ground Water and Subsidence at Coal Mines", as well as the receiving stream standazds issued <br />by the Colorado Water Quality Control Commission. Potential future uses for this groundwater <br />could be for agriculture, irrigation and domestic water supply. However, several of the aquifers <br />that could be affected by mining are coal seam aquifers. These are the HI, KLM and QR aquifers. <br />The non-coal aquifers that lie above the mined coal seams are the First, Second and Third White <br />Sandstone aquifers. Below the mined coal seams is the unmined U coal seam and the 20 Mile <br />Sandstone Aquifer. <br />There were several instances where certain chemical parameters had exceeded suspect limits for <br />at least one of the potential uses of the groundwater. These cases can be classified into four main <br />categories. First, there aze anomalous readings that do not appear to be part ofany trend. <br />Sporadic occurances of high iron concentrations in wells GD-1(2), GE-3, COY and P-5 are some <br />examples. Second, there aze high readings that are consistent with the historically high <br />background levels. Some examples are manganese in well GD-3, selenium in well P-5, sulfate in <br />wells GC-l, GC-2, P-3 and P-5 and TDS in wells P-l, P-3, P-5 and GP-5. Third, there are high <br />