C.C.A.T.

Impoundment Pond Leak Investigation

CDPHE requested two studies concerning the condition of the tailings impoundments, and the USEPA also requested an evaluation.  All three reports confirm and document concerns citizens have voiced for years about the installation of the impoundments in 1978-79.

2. The Sentinal report says: "Numerous springs and open bedrock fractures were encountered during impoundment construction. These conditions suggest that pathways exist for migration of impoundment seepage into both shallow and deep aquifers."

3. The EPA Breeden report says:  "At the present time, there are insufficient ground water monitoring data to determine if a release of liquids from the Primary and Secondary Impoundments has, or has not occurred. This is due to the inadequacy of the current monitoring well network."

 In 2006, Cotter installed several new wells along the edge of the impoundments, which were monitored for one year.

CDPHE reviewed the sampling data and concluded that one well indicated leakage from the impoundments.

4.  The CDPHE Analysis says:  "Based on the evidence presented, the Department determines there is evidence of a minor release of contaminated material from the Primary Impoundment as evidenced by physical and chemical evidence found in monitor well 379 as compared to surrounding wells during the evaluation period."