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Seneca Coal Company Seneca II-W Mine ~ June 2006 Phase I Bond Release Request • draglines. All areas afEeced by the surface mining operations, except as specifically exempted by the CDMG, were regraded on a timely basis to a stable configuration that conforms with the approved postmining land use (livestock grazing and wildlife habitat). Fox the most part, grading was done along contour to also m;n;m;ve erosion. Any time operations were conducted on steep slopes that could present safety concerns to the operators, grading was done in a direction other than parallel to contour. Exhibit D, Typical Cross Sections of Backfilled and Graded Area, provides representative cross-sections showing final topography configuration. Amore detailed discussion of the overall mining and reclamation can be found in the Seneca II-W Mine Permit Application, spedfically Tab 12, Operation Plan and Tab 2Q Backfilliug and Grading. Rill and gully surveys are conduced annually in the spring of each yeaz to identify aeeas that have experienced severe erosion ox other signs of instability during spring runoff fmm snowmelt and preclpitation events. Minor rills and gullies have occurred and been remediated over the past pears however, no major instances of instability have been identified in the pexrttanent program area requested for Phase I bond release. Included in the postmine regrading operation was the construction of small swales and hummocks to m;n;m;~e erosion and to conserve soil moisture and to promote xevegetation. Small stock tanks axe also utilized in the postmine grading operations to m;nim;~e erosion and to provide water for livestock and wildlife. The locations of these stock ponds aze shown on Exhibit C, Post Mining Topography Map. The designs and certified as-builts for the permanent stock ponds can be reviewed in the Seneca II-W Mine Pennit Application Tab 13, Facilities. Postmine drainage channels were designed and constructed to also control runoff and erosion. All of these channels were designed and constructed to control, at ]east the 10-year, 24hour storm event. In most cases where grades aze steep, the riprap used in the construction of the channels is 3+ inches larger than the design specifies. This conservatism used in the construction helps to ensure stability of the channels. The locations of these channels are shown on the attached Exhibit C, Post Mining Topography Map, while the as-built profiles for these channels are presented on Exhibit E, As-Built Drainage Profiles. The approved channel designs aze included in the Seneca II-W Mine Permit Application Tab 20, Backfilling and Grading. These postmine drainage channels all ultimately flow to sediment ponds to ensure that water quality leaving the permit area is within regulatory specified limits. The locations of these ponds axe also shown on the attached E.Yhibit C, Post Mining Topography Map. The designs and as-built documentation is contained in • the Seneca II-W Mine Pemtit Application Tab 13, Faalities.