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a 407 -acre watershed that drains into Sage Creek of which only 29.5 acres were <br />disturbed by mining activities. <br />Pond 016 was constructed in the summer of 2000 in the Seneca II -W south extension <br />area. The pond treats runoff from 382.2 total acres. Discharge from this pond goes <br />into an unnamed tributary of Hubberson Gulch. <br />Pond 017, constructed in the fall of 2002, treats runoff from a 955 -acre watershed <br />including mine disturbance areas from the southern portion of the south extension of <br />the permit area. The pond is located on upper Hubberson Gulch near the southwest <br />corner of the south extension area. Pond 017 construction certification and "As - <br />Built" designs were included in PR -4 submittal materials. <br />Several of the sedimentation ponds have been proposed as permanent <br />impoundments, and the impoundments would are warranted to facilitate post -mine <br />livestock grazing and wildlife use. Documentation required by Rule 4.05.9(13) has <br />been provided for most of the ponds to allow for approval of any sedimentation <br />ponds as permanent impoundments. Pond 006, Pond 016, and Pond 017 still require <br />approval by the Colorado State Engineer's Office. The following commitment is <br />included in Permit Tab 13, page 5, regarding permanent impoundment <br />demonstration of compliance: <br />Permanent impoundments will be reevaluated prior to bond release and <br />remedial construction performed to satisfy the appropriate sections of the <br />regulations. Prior to submittal of a bond release request, SCC will submit a <br />complete technical revision demonstrating that each permanent impoundment <br />meets the requirements of 4.05.9(13). <br />D. Acid-forming and Toxic -forming Spoil <br />The applicant has submitted detailed analysis of the geochemical characteristics of <br />the overburden and interburden found in the Seneca II -W Mine permit area. Initial <br />drilling and geochemical sampling was conducted within the baseline study area <br />prior to initiation of operations. Additional drilling and sampling was conducted <br />within the south extension area in 1991. Until the 2003 approval of PR -3, coal <br />extraction was limited to the Wadge seam, and the initial baseline studies were <br />focused on Wadge overburden assessment. Strata from the surface to immediately <br />below the Wadge coal seam were sampled. Core holes were distributed across the <br />Wadge recovery areas in both the original permit area and south extension area <br />(Exhibits 6-6 and 6-6A). <br />PR -3 allowed for surface mining of the Wadge, Sage Creek and Wolf Creek Seams <br />within the South Extension area. Characterization and assessment of Sage Creek <br />overburden, Wolf Creek overburden, and Wolf Creek underburden was based on <br />chip samples collected from Monitoring Well WWCU-24, which was drilled into the <br />Wolf Creek underburden near the western boundary of the south extension area in <br />N. <br />