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u' Revision q3- Pege 6 of 30 During the mining and reclamation process, all precipitation within the project site will be collected and remain on the project site. A drainage Swale will be installed along the north, west and south property lines, which will collect and divert surface Flows into a new retention pond located along the west property line. The retention pond has been sized in accordance with the City of Grand Junction standards. Mining for the sand and gravel, and for a portion of the backfill operations, will require dewatering. A pump will be used to dewater the excavation pit area and discharge into a new settlement pond constructed near the northwest comer of petmi[ area. The settlement pond will allow the sediment to drop out of the water before it is discharged offsite into the Canning Factory Ditch. The side slopes for the pond shall be constructed at a 3H:1 V, and all overburden removed for the pond construction shall be stockpiled around the pond perimeter. (dJ The size ojareas to be worked at any one time; Mining at the site will be progressive across the permit area, as discussed in part (a) above. The excavated pit area (backfill placement area, sand and gravel highwall, and overburden highwall) will be no more than three acres in size at any one time. The three-acre area has been established to limit the amount of imported reclamation fill required to reclaim the site to approximately 96,000 cubic yards. (e) An approximate timetable to describe the mining operation. The timetable is jor the purposes of establishing relationship between mining and reclamation during the different phases ojthe mining operations. An Operator shall not be required to meet specific dates jor initiation, or comp[e[ion of mining in a phase as may be identified in the [imelable. This does not exempt an operator from complying wish the performance standards stated ojSec[ion 3.1. Such timetable shal/include: • An estimate ojthe periods ojttme which will be required jor the various stages ojthe operation; • A description ojthe size and location ojeach area to be worked during each phase; and • Outlining the sequence in which each stage or phase ojthe operation will be carried out Mining for the sand and gravel will be progressive across the site, as discussed in part (a) above. As mining operations progress across the permit area, backfilling operations will be following behind the active sand and gravel highwall. The excavated pit area will be limited in size to no more than three acres in size at any one time. Once backfill has reached the site reclamation plan elevations, the area will be made available for material stockpiles and processing, or, if the area will not longer be needed, it may be tilled, topsoil replaced, mulched, seeded and fertilized. The operator proposes to delay topsoiling, mulching, seeding and fertilizing until the site has been mined for the sand and gravel. However, of there are areas within the permit boundary which will no longer be disturbed, the applicant may till, mulch, seed and fertilize these areas. Also discussed above, the topsoil will be stripped from areas before surface disturbance activities occur. The maximum area for topsoil stripping shall be 32.5 acres. (n Nature, depth, and thickness of the deposit to be mined and the thickness and type of overburden to be removed: and Nature ojthe stratum immediately beneath the material to be mined in sedimentary deposits. Overburden material within the project site is approximately 12 feet deep. According to the US Department of Agriculture, Department of Natural Resource Conservation Service (MRCS), the overburden soil consists of a silty clay loam that is not suited for cultivation due to high salinity levels. Vegetation on the project site consists of [amerisk, greasewood, and halogeton. These plants are listed on the State of Colorado's noxious weed list. The top two to six inches of existing topsoil material will be stockpiled and reused for site reclamation work.