Laserfiche WebLink
b) The liner soil will have a plasticity index between 10 and 35; <br />c) The percentage of gravel, defined as material retained on the No. 4 sieve, <br />will not exceed 10 percent; <br />d) The liner soil will be compacted to a minimum of 95 percent maximum dry <br />density as determined by the Standard Proctor (ASTM D698); <br />e) No brush, roots, sod, frozen material, or other deleterious or unsuitable <br />materials shall be incorporated into the fill. Fill shall not be placed upon <br />frozen material; <br />f) If moisture conditioning is required to meet the moisture content <br />specification, the added moisture shall be worked into the fill by harrowing <br />or other means until a uniform distribution of moisture is obtained; <br />Compacted soil liner fill shall be protected from desiccation and from <br />freezing. The finished soil liner will be covered as soon as practicable with <br />water as shown in the reclamation plan. If evidence of desiccation or frost <br />damage is observed, the soil liner will be reworked and retested as <br />necessary to demonstrate that the compaction specification is met, <br />h) Large rocks (greater than 2 inches) will be removed from the soil liner fill. <br />Soil clods larger than 4 inches will be broken up. <br />Construction Procedure <br />A detailed construction procedure is given here to develop the basis for a quality <br />assurance plan and provide the operators with a step by step schematic plan that <br />will guarantee a quality compacted liner. <br />Maintaining the proper moisture content will be critical to ensure adequate <br />compaction. It is highly recommended that the specified moisture content be <br />achieved prior to removing the shale from the pit floor. An area of pit floor shall <br />be disked, watered, then allowed to sit for a until moisture content stabilizes <br />(approximately 24 hours) before stripping and placing clay liner material. Field <br />testing shall be performed during construction by a qualified geotechnical <br />engineer and shall consist of moisture content testing prior to excavation of <br />borrow material as well as moisture content and density of the compacted lifts at <br />least once every 10,000 yd <br />A backhoe will be used to dig a trench or keyway into bedrock. Weathered shale <br />will be backfilled and compacted into the keyway as described below. A <br />conceptual cross section of the liner is given in Exhibit F Sheet 2, Typical Cross <br />Section. <br />g) <br />EXHIBIT E — RECLAMATION PLAN <br />Weathered Pierre shale removed from the pit bottom will then be placed along <br />the perimeter of the pit to construct the compacted clay liner. Shale will be <br />placed in 1 -2 foot lifts. A Scraper should be used both for stripping and placing <br />the shale into lifts followed by a sheep's -foot roller /compactor. Each 1 -foot lift <br />Challenger Pit <br />M-198%.026 TR -04 <br />Page 4 of 6 <br />