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• Monument View Gravel Pit • <br />FILE #: M-2000-032 <br />SUMMARY RESPONSE TO STATE COMMENTS <br />6. Exhibit D -The app/ication indicates, no more than 50,000 cubic yards ofbackfi// wi/l be <br />required at any time during the operation, and that S0, 000 cubic yards of fi// wi/l be <br />maintained onsite for this purpose. However, this doesn't not appear to be an operations//y <br />feasib/e p/an. /f the pit reaches the maximum depth of32 feet, then it wou/d have to be /ess <br />than an acre in sire for 50,000 cubic yards ofmateria/ to be adequate vo/ume for backfi//ing. /f <br />the pit is to be a maximum of 5 acres in size at any one time, then a stockpi/e of 258,000 <br />cubic yards offi// materia/ wou/d be required to be maintained on thesite at a// Limes during the <br />operation, except while excavating Phase 1-A. Please create a soil bafance far the proposed <br />operation and ensure the mining and rec/amation p/ans adequate/y address hoe the mining and <br />backfi//ing wi// be performed to arrive at the proposed post-mining configuration. <br />RESPONSE: The mining plan has been revised to reflect a "progressive" mining operation. <br />The excavation area (backfill area, sand and gravel highwall, and overburden highwall) will <br />be limited to a maximum of three acres in size. A three-acre disturbance should require <br />130,000 to 150,000 cubic yards of fill material. <br />7. Exhibit D - P/ease provide detai/s of how the mining and rec/amation operations wi//mesh: (i.e. <br />will the pit e a progressive pit where the five acres moves through the permit area with <br />rec/amation being conducted concurrently (at the back of the pitJ whi/e mining occurs at the <br />highwa// face, or wi// the preceding 5 acre pit be comp/ere/y mined and back£//ed before <br />initiating excavation of the next sequential pit.J <br />RESPONSE: The section has been revised to reflect a progressive mined pit, limited to three <br />acres mined at any one time <br />B. Exhibit D -What wi//be the maximum height and length of the headwa// during mining <br />operations? <br />RESPONSE: The overburden highwall is expected to be 12-ft high and a maximum of <br />400-ft long, and the sand and gravel highwall is expected to be a maximum of 17' tall and <br />400-ft long <br />9. Exhibit D - Wi// the overburden be stripped off ofthe block that is to be used for the crushing, <br />processing and stockpi/ing area? <br />RESPONSE: The topsoil material will be stripped from these areas, but not the <br />overburden. <br />10. Exhibit D - /t appears the site wi//require dewatering during the mining process. P/ease provide <br />detai/s regarding how the dewatering system will be set up in each phase and how it wi/l operate. <br />RESPONSE: Dewatering will progress with the mining operations. A six-inch diesel pump <br />is planned to be used in the sand and gravel highwall, and backfill areas, to keep the area <br />dewatered. The water will be pumped to a settlement basin located along the north side of <br />the site. The settlement pond will be approximately 3 acres in size. The water will Flow <br />from the settlement pond into one of two permitted discharge points located along the <br />north boundary of the project. <br />RG Consulting Engineers, Inc. PAGE 2 OF 5 <br />Sra[e Commen[ Response.doc <br />