2008-01-08_PERMIT FILE - M2008001 (8)

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generally used to dig the trench into anon-pervious bedrock layer that underlays the permeable, excavated overburden. Once the trench is excavated and while maintaining the bentonite slurry, the trench is back filled with an impervious mixture of blended overburden and bentonite; overburden, cement and bentonite; or cement and bentonite. The backfilled trench is then covered with a cap to protect the backfilled trench from deterioration. Over this and the surrounding area, down to the toe of the reservoir basin will be placed a course gravel layer to protect the surface area from erosion and inhibit the growth of vegetation. The Applicant/Operator will provide detailed designs in the form of a Technical Revision at a future date once other key permits and approvals are obtained from other agencies. No slurry wall construction will begin until the Technical Revision is approved. Conceptual slurry walUdam designs and specification are provided in Appendix II. A commitment to a QA/QC acceptable to the Division are provided in Exhibit "E". This allows the Operator/Applicant to calculate a bond sufficient to take advantage of the 20% bonding option. • Relocation of the Excelsior Ditch: The Excelsior Irrigation Ditch is a functioning structure that crosses portions of both the East and West Pits. Portions of the ditch will be relocated to the north ~ edge of the East and West Pits permit boundary, adjacent to State Highway 96 - East ROW (US 50). The relocated Ditch will be constructed using typical earth moving equipment suitable for the job such as bucket excavators, dozers, scrapers and motor-graders. The cross-sections and designs for the proposed Excelsior Ditch relocation will be engineered to carry the historical volume of ditch water. • Water pipelines: Several buried water delivery pipelines will be constructed as part of the developed water resource reclamation plan. A buried inflow water pipeline will run from the Excelsior Ditch via a diversion structure to the West Pit. A connecting buried water pipeline will run from the West Pit to the East Pit within a 40 foot easement. A buried discharge water pipeline will run from the East Pit to the Arkansas River. The buried pipelines will be installed in excavated trenches with appropriate bedding materials, obtained from the sand and gravel extraction operation. Trenches and placement of the steel welded pipe 42" diameter waterlines will be accomplished using equipment suitable for such construction, such a long reach backhoes, draglines, dozers, frontend loaders and motor-graders. Upon completion of pipeline installation, all associated affected lands will be reclaimed according to the approved reclamation plan.