PERMFILE70400 - Laserfiche WebLink

Home Browse Search

01/08/2007 18:19 3032748329 BANKS AND GESSO LLC PAGE 02/06 ~~ Banks and Gesso, LLC ~~ January 8, 2007 Rick Wenzel Colorado Division of Reclamation, Mining, and Safety 1313 Sherman St., Room 215 Denver, CO 80203 720 Kipling St.,Sufte117 Lakewood, Colorado 80215 {303) 274.4277 Fax(3D3)274-8329 www. ban ksand gesso. com Fte: Grand River Park Project, Addendum to January 3 Adequacy Response Dear Mr. Wenzel: Based on our meeting concerning the Grand River Park Project Regular 112 permit application on January 5, 2007, this memo is intended to clarify proposed spec cations for drainage features on the M-2006-046 site. AS noted during review of the January 3, 2007, second adequacy response, water management plans for the site have been revised to eliminate certain physical elements that are redundant or counterproductive. Regarding the justification for modifications to the former clarification basin and spillways, please note the following: 1. Clarification of Comment 10. The consulting engineer's (Mr. Ramsay M. McDermid, P.E.) discussion of the dimensions of the "clarification basin" was composed early in the preparation for the applicant's January 3, 2007, adequacy submittal. Most recently, in December 2006, following the drafting of the Water Management Plan, the consulting engineer informed Banks and Gesso, LLC, of a revised estimate for the basin dimensions at the northern end of mining Phase 1B. The new scheme to implement water quality functions prior to pumping eliminates the need for sediment release in a large, slow-flow pond. The re-drawn "regulating pond" has a 750,000 gallon storage requirement, in accordance with water management needs. Mr. McDermid provides other details of the regulating pond in the Water Management Plan, submitted in response to Comment 21f. The dimensions cited by Mr. McDermind in his narrative for Comment 24 are superceded and specifically defined by a more recent size estimate in the applicant's response to Comment 10.