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13 <br />Data collected on the South Block in 1946 show relative production diversity distribution <br />comprised of 90.3 % perennial grasses. 6.6 % alfalfa, and 3.1 % annual, biennial and perennial <br />fortis. The most dominant species on the South Block is Smooth brome comprising 5?.l% <br />relative cover in the 1996 sampling. No single species exceeded 75 % relative cover. The 1997 <br />South Block relative production sampling data showed the vegetative diversity composed of <br />87.4 % perennial grasses, 8.0 % alfalfa, and 4.6 % perennial, biennial and annual fortis and <br />annual grasses. Consistent with the North Block data. Smooth brome is the dominant species at <br />43.1 % relative cover. No single species exceeded 75 % relative cover. The vegetative species <br />diversity on the South Block meets the diversity standard for both 1996 and 1997. <br />The re-established vegetation is comprised of cool season species. The mine is located in a region <br />characterized by high elevation, cool temperatures and heavy snowfalls. Warm season plant <br />species aze not indigenous to the region. The bond release areas are in compliance with Rule <br />4.15.8(6). No woody plant standard applies to this permit area due to the post-mining land use of <br />pasture. Woody plant density was not measured or evaluated as a part of this bond release. <br />B. Hydrologic Impacts <br />In accordance with Rule 3.03.2(2), the Division is required to make an evaluation of whether <br />pollution of surface and subsurface waters is occurring, the probability of future occurrence of <br />such pollution, and the estimated cost of abating such pollution, prior to releasing any <br />performance bond at a site. <br />Baseline water quantity and quality parameters, and data collected representing existing water <br />quality as of January 31, 1994, where available, were compared to 1998 data for Energy Mine <br />No. 3. <br />1. Bedrock Water Ouality <br />We11008-77-58 (see following table) is completed in the Wadge overburden down gradient of <br />the reclaimed pit area. A marked decline in water level in this down gradient well corresponds to <br />an increase in total dissolved solids in January of 1980, from approximately 300 mg/1 to 1600 <br />mg/l. This indicates that this well responded in a relatively short period of time to up gradient <br />mining activities, and is appropriate to identify potential changes in water quality and quantity <br />due to mining at Energy Mine No. 3. Average water level and quality for important parameters <br />are represented below for three periods. <br />Colorado Yampa Coal Company: Mine No. 3. SLO? Findings 6/99 a:\COBa06?\SLO?Ind.doc <br />