Laserfiche WebLink
Mr. Tom Kaldenbach <br />October 19, 2000 <br />Page 3 <br />this particular area to access the underlying H and I coal seams and questions whether the Third <br />White could be the source of the continued inflow necessary to produce the resulting water quality <br />improvement at well GF-5. <br />However, Trapper believes the QR aquifer could be providing underburden flows in this area. The <br />potentiometric surface of the QR aquifer in the vicinity of well GF-5 nearly coincides with the <br />backfill water level at this location whereas the QR potentiometric surface lies well below the <br />water level observed in well GF-7. This infers that QR underburden inflow contributions in the <br />vicinity of well GF-5 are likely and conversely are much less pronounced in the vicinity of well <br />GF-7. This could further explain the difference in water quality exhibited at these two sites (see <br />comment 11). <br />1 I.) The PHC text has been revised to replace this paragraph with a discussion explaining the water <br />quality variation seen at different backfill wells at Trapper and addressing the potential for water <br />quality to be affected by ash. <br />12.) The text has been changed per your request. <br />13.) See response 7. <br />14, I5, 16.) This section of text has been revised to reflect the changes suggested. The impacts are <br />characterized as significant to the Johnson Gulch drainage but insignificant when viewed from the <br />perspective of the Yampa River system. <br />17, 18.) Text in this passage of the PHC has been revised per your suggestions. <br />19, 20, 2l.) The PHC text has been revised in this section to describe the possibility of a TDS affected <br />groundwater plume developing and migrating to the north of the mined area in Flume Gulch. <br />Trapper believes a text description is sufficient to describe the projected hydrologic influence of <br />mining in the Flume Gulch area. The origin of the affected water and extent of the low-wall <br />expected to convey this water is described and time estimates are provided for the plume to reach <br />established monitoring points in the vicinity (well GC-2, well GP-9). <br />22.) The text has been revised per your request. <br />23.) The last phrase of this paragraph referencing the East Pyeatt Spring has been deleted. The text is <br />intended to clearly specify that the water quality from samples collected prior to 1999 represents <br />that found at the S-1 location. During low flow periods, the water at this site emanates from <br />springs further up in the watershed. <br />24.) The text has been modified per you request. <br />