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The logic followed, in arriving at the conclusion that the interburden contains insufficient water to be classified, should be explained in detail on page 16 of Tab 7 (paragraph 2) of the permit application package (PAP). PWCC should provide as much supporting documentation as possible with the explanation. The supporting documentation should include, but is not limited to, the hydrograph for Well 3EI (which appears to have been excluded from the PAP) and any field observations or notes concerning the hydraulic properties or water levels in the interburden. b) The interburden does not appear to be in hydraulic communication with either the Wadge Coal or the Wolf Creek Coal. This is based primarily on the fact that, according to Table 7-3 of the PAP, the mean artesian head in the Wolf Creek Coal (lower coal seam) is between 10 and 200 feet higher than the mean artesian head in the Wadge Coal (upper coal seam). In addition, the groundwater in the interburden is reported to be under non-artesian conditions. If the two coal seams were in hydraulic communication through the interburden, then the head in all three units would be expected to be approximately equal. However, because of the great water level fluctuations observed in the coal seams (up to 48 feet in the Wadge Coal and up to 40 feet in the Wolf Creek Coal), mean artesian heads are not reliable criteria for evaluating the hydraulic relationship between the two coal units. Therefore, we request that PWCC provide existing raw, simultaneous water level data for wells clustered in the Wadge and Wolf Creek Coals. As stated previously, any documentation that exists to support PWCC's assertion that the groundwater in the interburden is under unconfined conditions should be provided. As an additional note, PWCC's statement in the last paragraph of page 6 of the adequacy response seems to imply that PWCC interprets Rule 2.05.6(3)(b)(iv) to mean that a prediction of "no significant impacts" in the Probable Hydrologic Consequences (PHC) section of the PAP waives monitoring requirements. On the contrary, we advise PWCC that "no significant impacts" predictions must also be verified by monitoring. The argument against monitoring ground water in the interburden is supported, not by the "no significant impacts" prediction, but by the factors mentioned above, specifically, that the interburden appears to contain insufficient water to be classified as an aquifer, and that the interburden does not appear to be in hydraulic communication with the coal seams. If you have any questions or need additional information, please contact me. Sincerely, . jZS^'ZGlztt~~~h~j't2Qc.~/1 Susan L Burg ter Environmental Protection Specialist c: Barbara Pavlik, CDMG s[.s~m~sva.wr ary en t 2 anuary 2 , 1