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Ms. Erica Crosby Sep(ember 7, 1999 Page 3 The ditch is unlined. Some waters in the ditch currently seep into the groundwater system as they make their way to the river. The limit of mining is set back a minimum of 30 feet from the top of the ditch banks. The inside ditch banks aze approximately 2H:1 V and aze fairly well vegetated. There are two ditch access roads along the top of the banks on either side of the ditch. These roads will remain and are within the 30 foot top of bank setback. The attached slope stability report indicates the ditch banks are stable at the proposed mining slopes. As the lake to the west of the ditch is proposed to be lined, there should not be any seepage of the waters in the ditch going into the lake or visa verse. The area to the east is proposed to be backfilled and will be slightly less porous than before. This should reduce some of the seepage losses from the ditch. Attached is a copy of a new application to the Office of the State Engineer for a Substitute Water Supply Plan for this site. Timing on certain aspects of the S WSP prevented us from simply moving the existing SWSP to this site. The SEO generally takes two to three months to approve a new SWSP. A copy of the approval letter will be supplied to the Division when it is received. Water will be obtained from the existing Kauffman Pit (M-78-327) for dust control of the proposed operation as is currently the practice of Kauffman's for all the surrounding pits. The applicant will purchase water to fill the reservoir from a private source acceptable to [Ite Office of the State Engineer's. This water will be used for the initial filling of the lake. The post-mining land use for the property will be pastureland for Phase I, pastureland for Phase II, and developed water resource for Phase III. The applicant would set the following specifications for the design and construction of the clay liner for Phase III of the pit. The clay and overburden material shall be reasonably well graded with a minimum of 45% by weight of the particles passing the #200 sieve. No rocks larger than 3 inches shall be allowed in the embankment. The liner material shall have a PI of ] 3 and shall meet the standard for being classified as a CL material under the UCS criteria. The material shall be tested for permeability using the falling head permeability method and shall be sufficiently impermeable to meet the criteria of the State Engineers office. The material shall be compacted using ASTM D-698 Standard Proctor Density testing. All material shall be compacted to 95% of maximum density within 2% of optimum moisture content. Testing shall be done each 9 inch lifr with a minimum of one test for every 1,000 CY being placed or at least one test per lifr, whichever is more. The material shall be compacted using scrapers and a sheepsfoot roller. Any material lefr overnight shall be scarified, and brought to optimum moisture content prior to placing additional lifts on it.