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Installation: The Division generally accepts Denison's proposed plan. To clarify and/or reiterate, the following <br />comments are included herein. Surface preparation prior to liner deployment will include the placement, grading and <br />compaction of the soil substrate such that it produces a smooth surface on which to bed the liner. The soil substrate <br />should be screened, placed, and compacted as proposed. The compaction of the soil substrate should be tested at least <br />once prior to placement of the liner to verify adequate compaction of material (per manufacturer's liner requirements). <br />All bedding material will be visually inspected prior to liner deployment, and all particles larger than 3/8 inch, or other <br />angular or protruding materials, must be removed to maintain integrity of the liner. The anchor trench along the <br />perimeter of the geo-membrane must be a minimum of 1 foot deep and 1 foot wide; 2 feet deep and 2 feet wide is <br />preferable. A perimeter berm must be included to prevent runoff and runon, yet must be traversable by equipment and <br />not allow damage to the liner. The anchor trench should be located at least a foot outside the crest of the berm. Trench <br />backfill materials must be adequately compacted. The liner cannot be deployed when temperatures are below 35 <br />degrees F, or when there is precipitation (or per manufacturer's recommendations, whichever is more conservative). <br />Liner material will be covered to a depth of at least 1 foot of clean and screened earthen fill, to be placed and spread as <br />proposed. All preparation and installation must proceed according to the approved plan, and overseen and documented <br />by qualified onsite QC monitor, who, per Hard Rock/Metals Rules, must be a Colorado registered PE. <br />Testing and Certification: All liner deployment QA/QC will include trial seam testing, field seam testing (pressure <br />testing), and destructive testing (at a location selected by the QC monitor). Destructive testing of the field seamed geo- <br />membrane will be approximately 24 inches along the seam and 12 inches across the seam, one sample each day or <br />every 500 feet along the seams. <br />Agreement by Operator: After questions and issues have been addressed, written agreement to the final plan and <br />design is required from the operator. Upon receiving the operator's agreement, the Division will prepare any final QC <br />specifications and standards for uranium ore storage, in a formal memo to the operator. DRMS will also issue its <br />written approval of the design and plan. <br />Please respond to the above items within 30 days of the date of this letter, by sending two sets of response materials <br />directly to me at the Division's Durango field office: 691 CR 233, Room A-2, Durango, CO 81301. If there are any <br />questions you may send them to me at the same address. <br />Sincerely, <br />Bob Oswald <br />Environmental Protection Specialist <br />Encl: memo <br />C(w/encl): Steve Shuey, DRMS <br />Barney Buria, BLM Montrose <br />(c:\10-02 docs\Van4 epp liner adq/rco)