HYDRO20603 - Laserfiche WebLink

Home Browse Search

• • iiiiiiiiiiiiiiiiii STATE OF COLORADO DIVISION OF MINERALS AND GEOLOGY Deparimem of Natural Resources 131 3 Sherman 51., Ruom 215 Denver, Colorado 80203 Phune' (}031 866-3567 FA%: 1303) 8}?-A106 DATE: August 25, 1997 Y ' n TO: Berhan Keffelew `~~/~// FROM: Harry Posey J ""~~ ~I ~V RE: Drafr letter to CC&V regarding hydrological and geochemical studies and modeling for Cazlton Tunnel discharge ~" ~~~~~ DEPARTMENT OF NATURAL RESOURCES Roy Romer Governor lames 5. Lochhead Eaecmive Dnectar Michael B. Long Division Director The following language should address the concerns voiced at our August 22 meeting regazding potential acid rock drainage in the Carlton Tunnel discharge. V/hether there is a potential for the Cresson operation to generate acid or dissolved metals in excess of applicable water quality standards at the Carlton Tunnel discharge is an issue that has not been resolved. The operator has stated there is adequate buffering capacity in the rock beneath the surface operation to neutralize acid rock drainage and precipitate excess metals and thereby to meet the Carlton discharge standards. The Division has contended that the evidence presented by CC&V in support of this interpretation is not adequate to support the interpretation. On May 23, 1997, Division personnel met with CC&V representative, John Hardaway, and CC&V's consultants, Adrian Brown Consulting and Shepherd-Miller. The purpose of that meeting was to lay out a framework for hydrological and geochemical modeling studies that would resolve the issue of potential acid rock drainage in the Cazlton Tunnel. It was anticipated by the operator and the consultants at that meeting that the hydrological and geochemical modeling studies would be complete and delivered to the Division by August 1, 1977. To date, the studies have not be been received. However, the Division has indicated, informally, that the deadline for receipt of these studies might be extended, provided there was an essential need. Therefore, with regazd to the hydrological and geochemical studies and groundwater modeling, the Division will require the following: CONDITION: By September ] 0, 1997, Cripple Creek and Victor Mining Company will deliver to the Division the required studies and models. Provided said studies and models cannot be completed by that date, the Operator will arrange a meeting with the consultants, the Division and the Operator to explain the progress of the studies and modeling, and to determine how to proceed. cc: Bruce Humphries