2004-10-28_REVISION - M1999021 - Laserfiche WebLink

Home Browse Search

Mr. Allen C. Sorenson, Division of Minerals and Geology October 26, 2004 Page Two AGGREGATE INDUSTNIES commit to continued monitoring of existing wells until such time that the DMG determines that continued monitoring is no longer necessary, based on an analyses of data and request to discontinue monitoring that will be prepared and submitted to DMG by Aggregate Industries. Aggregate Industries commits to continued monitoring of existing wells until reclamation is complete and the DMG releases the financial warranty bond. 4. Provide a design and specification for the armoring to bEr installed in the proposed reservoir spillway and describe the design basis for the sizing of the spillway and the riprap. The design specifications given below are based on the reclaimed condition of the site when the water storage reservoir is filled to a water level controlled at elevation 5037, which elevation would maintain storage of water in this azea at or below the existing natural ground surface. Type M riprap (ds° = 12") will be used in the reservoir spillway. Iffine-grained soils are encountered when constructing the overflow channel, two options aze available for riprap bedding. Either a two-layer filter using 4" Type I ganulaar material meeting CDDT's concrete sand specification AASHTO-M-6 (CDOT Section 703.1) over 4" Type I[ granular material meeting CDOT's Class A filter material (Section 703.09 Class A) or a single layer filter using 12" Type II granular material meeting CDOT's Class A filter material is acceptable (Urban Strom Drainage Criteria Manual -Volume I). If coarse- grained soils are encountered (50% or more by weight is retained on the #40 sieve), then 6" of Type II granular material meeting CDOT's Class A. filter material may be used. Please contact me if you have any further questions in this matter. Very truly yours, ~~~ Connie N. Davis Land Resources Assistant cc: Aggregate Industries-WCR, Inc.