2011-02-09_ENFORCEMENT - M1977300

Home Browse Search

Environmental Studies of the Mine On June 6, 2008, the Division advised Cotter that the Mine was a Designated Mining Operation ("DMO").3 AR:00031; 00425; 00868:23-00869:3. The Operator of a DMO is required to submit an EPP in accordance with the Act and the Board's Mineral Rules and Regulations for Hard Rock, Metal, and Designated Mining Operations ("Hard Rock Rules"), AR:00031, which Cotter did. Ralston Creek flows into Ralston Reservoir downstream of the Mine. AR:00050. Some attenuation of uranium concentrations occurs from chemical processes or dilution after Ralston Creek flows past the Mine and before it reaches the intake for Ralston Reservoir. AR:877:10-12. Ralston Reservoir receives significant water flows from other sources besides Ralston Creek. AR:00354. The nearest water supply intake, the Moffat water treatment plant, receives combined flows from Ralston Creek and South Boulder Reservoir. AR:00203. Denver drinking water produced at the Moffat treatment plant does not contain elevated levels of contamination. AR:00358. Similarly, Arvada drinking water meets State and Federal drinking water standards. AR:00365. The alluvial fill area is about seven acres. Order ¶ 3, AR:00846. The alluvial fill is partially composed of waste rock a Order ¶ 3, AR:00846, 00043; 00049. The alluvial aquifer is 3 On May 20, 2008, House Bill 1161, 2008 Colo. Sess. Laws 935, was signed into law and made various changes to the Act, including a change to the definition of DMO. Under House Bill 1161, all uranium mines were defined as a DMO. See Colo. Rev. Stat. § 34-32- 103(3.5)(a)(III). 4 It is unclear if Cotter owned the Mine at the time the waste rock was placed. Mining started in 1953 and Cotter did not own the Mine until 1966. AR:00925:10-14; 00423. No evidence in the record therefore supports paragraph 43 of the Order that Cotter placed waste rock containing uranium in the alluvial fill. AR:00852. 7