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<br />mining/Mining Plan, Exhibit C, the ground surface elevation in the Phase [area is <br />approximately 5055 feet amsl. Rocky Mountain Arsenal (RMA) ground water contour <br />maps produced from 1996 and 1997 data indicate that the ground water elevation beneath <br />the same area was approximately 5035 feet amsl, or 20 fee[ below the ground surface. <br />These estimates support the values received from the State Engineer's Office. <br />For the purposes of estimating reclamation costs, the applicant is providing an altemative <br />reclamation plan and itemized tasks for the Phase I area (see response to number 12 <br />below). This alternative reclamation plan includes backfilling the Phase I excavation to 2 <br />feet above the ground water table, topsoiling, and reseeding to provide a stable vegetative <br />cover. <br />From exploration boring data, the depth to bedrock in the Phase I area is approximately <br />31 feet below the ground surface. The estimated depth to ground water is 22 feet below <br />the ground surface. Backfilling of [he Phase I area to 2 feet above the ground water table <br />would, therefore, require 1 l feet of fill over [he entire 13.2 acres. Above the I 1 feet of <br />backfill, additional backfill will be required to grade 3:1 slopes to the excavation crest. <br />Based upon this reclamation altemative, 303,150 cubic yards of backfill material wilt be <br />required. It is estimated that approximately 120,000 cubic yards will be provided by the <br />settling of process fines, leaving 183,150 cubic yards to be provided by overburden <br />material. <br />8. In [he absence of a specific liner design for [he Tanabe Pit, the Division requests that the <br />operator conunit to securing design approval from the OSE prior to construction and to providing <br />the Division with a technical revision to the reclamation plan in the event [hat an alternative <br />design is used. <br />• According to the State Engineer's Office, "design approval prior to construction" is not <br />necessary or available from their office. The State Engineer's Office is concerned with <br />the liner meeting performance standards during an initial test of competency, as well as <br />during the ongoing operation of the reservoir. <br />The applicant will, however, submit the liner design and construction plans to the State <br />Engineer's Office for review prior to construction. The liner design and construction <br />plans, and any comments provided by the State Engineer's Office, will be forwarded to <br />the Division. If an alternate design (significantly different than the "typical" design <br />previously submitted) is used, the applicant will provide the Division with a technical <br />revision to the proposed permit reclamation plan. <br />12. There are no provisions for site grading or revegetation of tl~e 32.2 acre wetland in the Phase <br />I area. At a minimum, the applicant will need to provide a grading plan showing the <br />approximate contours or slopes of the wetland area, plans for revegetation of the created <br />wetlands, and itemized reclamation costs for such tasks. <br />As an alternative, the operator may provide an altema[e reclamation plan for the 32.2-acre <br />wetland area. <br />Page 2 <br />