Laserfiche WebLink
Concentrations of total dissolved solids (TDS) are four times higher for water coming <br /> from the Rail Loop Pond than water from the Truck Loop Pond; however, TDS <br /> concentrations coming from the ponds are generally less than ambient concentrations in <br /> Dry Creek upstream. Existing water quality in Dry Creek is unsuitable for irrigation and <br /> only marginally suitable for livestock. <br /> The majority of the runoff from the rail loop, as well as the runoff from the three small <br /> area exemptions in the Loadout area, is not treated; however, runoff from these sources <br /> passes through a vegetative filter and does not appear to affect water quality. No adverse <br /> impacts from mining operations were projected in the HGT PAP and none have been <br /> observed to date. <br /> Runoff from the Loadout area that is not diverted around the area of disturbance is <br /> retained in sedimentation ponds for a maximum of 36 hours. Water retained in the two <br /> sedimentation ponds experiences some losses through evaporation and seepage. The <br /> Dry Creek diversion downstream could potentially be impacted by losses of water due <br /> to storage in the sediment ponds. <br /> The acreage served by the two sediment ponds accounts for less than one -thousandth <br /> of the acreage drained by Dry Creek. Since the area to be affected is a fraction of the <br /> total watershed, the watershed will not be significantly affected and runoff from the <br /> permit area will continue to reach Dry Creek. <br /> All waters utilized for dust suppression, showers, and other operations at the Loadout <br /> were piped in from a well in the Yampa River alluvium (H—G Shallow Well No. 1), <br /> located two miles north of the Loadout. H -G Shallow Well No. 1 was sealed in 2011. <br /> HGT owns an additional 90 acre-feet of water rights in the downstream Walker Ditch, <br /> which are not currently being utilized. Facilities were dismantled in 2011, and the <br /> remaining office trailers were removed from the site in 2013. Plumbing to the trailer <br /> was dismantled during the removal of the office trailers. <br /> These water rights can be utilized to compensate any downstream users for loss of water <br /> due to consumption at the Loadout. In addition, HGT has an agreement with the United <br /> States Fish and Wildlife Service (USFWS)to mitigate against losses of water to the <br /> Yampa River as a result of water consumption at the Loadout. Please refer to Volume 3, <br /> Tab 21 of the permit application and Item XII of this document. <br /> 2. Ground Water Impacts <br /> The Lewis shale has low conductivity values and is generally considered to be an <br /> aquitard that retards transmission of surface water to the Twentymile Sandstone, the <br /> underlying regional aquifer. This low conductivity unit results in low well yields <br /> that preclude the use of waters from the Lewis shale for other than stock watering <br /> (See Seneca II-W Permit, C- 1982- 057, Tab 7). Water samples from the two <br /> existing alluvial wells at the Loadout, which are completed in part in the underlying <br /> 21 <br />