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February of 2006.
<br /> The Wadge coal seam is overlain by 50 to 60 feet of sandstones, with interbedded shales and
<br /> siltstones. The thickness of the Wadge coal that was mined was 9 to 13 feet. The Wolf Creek
<br /> coal seam is overlain by 150 to 215 feet of sandstones, shales, siltstones, and thin coals. The
<br /> Wolf Creek seam, in the area that was mined, ranges from 12 to 18 feet in thickness.
<br /> Production rates at the mine for the operational period ranged from 137,000 tons per year to
<br /> 1,031,330 tons per year. The mine operated through 2006, averaging 730,000 tons per year for a
<br /> total of 7.7 million tons of coal.
<br /> The mining process included clearing of vegetation, topsoil removal, overburden blasting and
<br /> removal, and coal blasting and removal. Reclamation was contemporaneous with mining, and
<br /> included backfilling, grading, topsoil redistribution, and reestablishment of vegetation.
<br /> Vegetation was cleared and either disposed of in the active pit, or placed on reclaimed areas for
<br /> use by wildlife as cover. Topsoil was removed in advance of mining operations by scraper
<br /> equipment, then stockpiled or redistributed when possible. Stockpiles were temporarily stabilized
<br /> with the establishment of vegetation. Overburden was blasted and removed with a dragline, then
<br /> spoiled into the previous pit. The initial box cut spoil was temporarily placed on an adjacent
<br /> unmined area, and the spoil subsequently double handled for placement back in the pit once the
<br /> next pit was opened. Coal was ripped or shot, removed by loader, and transported via Road A to
<br /> the Hayden Station power plant or to the Hayden Gulch Loadout facility (C-1992-081).
<br /> No crushing, screening, or washing of coal occurred, and the operation did not produce coal mine
<br /> waste. Non-coal waste was disposed of offsite at an approved dumpsite. Spoiled overburden was
<br /> graded by bulldozers to approximate original contour. Several drainages were reconstructed in
<br /> the mined areas, as depicted on Exhibit 20-2 of the permit application package. Topsoil was
<br /> redistributed by scrapers to an average thickness of 1.8 feet. The approved reclamation seed mix
<br /> was then drill seeded in the fall of each year, unless topsoil redistribution was completed in the
<br /> spring. In that case, a cover crop was sown, followed by the permanent mix the following fall.
<br /> Concentrated islands of seeded and transplanted shrubs were established on approximately five
<br /> percent of the reclaimed area.
<br /> At the end of mining, all surface facilities were removed, the areas regraded, topsoil redistributed,
<br /> and revegetation accomplished as described above.
<br /> Impacts to surface water and ground water have been and will continue to be mitigated and
<br /> monitored. Surface runoff from all disturbed areas is channeled to one of several sedimentation
<br /> ponds. Ponds 010, 011, 011a, 012, 012a, 013, and 014 have been constructed to date. Surface
<br /> water is monitored upstream and downstream of the site on Grassy Creek, Annand Draw, and
<br /> Sage Creek. Ground water is monitored in the Trout Creek aquifer, in spoils aquifers,natural
<br /> springs, and in the alluvium of Sage Creek, Grassy Creek, Annand Draw tributary, and Grassy
<br /> Creek tributaries.
<br /> Water usage at the mine consisted of dust control on roads and in pit areas. Water used in dust
<br /> control was obtained from Pond 002 at the Seneca II Mine. Seneca Property LLC has obtained
<br /> rights for all water usage at the operation.
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