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Dry Creek diversion downstream could potentially be impacted by loses of water due to storage in these sediment ponds. The acreage served by these two sediment ponds accounts for less than one- thousandth of the acreage drained by Dry Creek. Since the area to be affected is a fraction of the total watershed, the general watershed will not be significantly affected and runoff from the permit area will continue to reach Dry Creek. All waters used for dust suppression, showers and other operations at the loadout are piped in from a well in the Yampa River alluvium (H-G Shallow Well No, 1), located two miles north of the loadout. HGTI owns the water rights for this well. HGTI owns an additional 90 acre feet of water rights in the downstream Walker Ditch which are not being utilized. These water rights can be used to compensate any downstream users for loss of water due to consumption at the loadout. HGTI has also entered into an agreement with the United States Fish and Wildlife Service (USFWS) to mitigate against losses of water to the Yampa River as a result of water consumption at the loadout. Please refer to Volume 2, Tab 21 of the permit application and Item XII of this document. Probable Effects on Ground Water Quality: Bedrock Ground Water The Lewis shale has low conductivity values and is generally considered to be an aquitard that retards transmission of surface water to the underlying regional aquifer, the Twentymile sandstone. This low conductivity results in low well yields that precludes the use of waters from the Lewis Shale for other than stock watering (See Seneca II-W Permit Application, Tab 7). Water samples from the two existing alluvial wells at the loadout, which are completed in part into the underlying Lewis Shale, often exceed water quality standards for stock watering. Operations at the loadout should not impact this ground water. Alluvial Water Alluvial waters are also of poor quality and may be unsuitable for use in irrigation. Leachate from coal stockpiled at the loadout could potentially infiltrate the alluvium and add dissolved chemical loads to the Dry Creek alluvial aquifer, however, impact to Dry Creek alluvial water quality should be minimal due to the size of the operation and the composition of the coal. An alluvial ground water monitoring system to be put into place should serve to document this conclusion. 21