Laserfiche WebLink
AM-02 EPP Adequacy Review 7 14 December 2010 <br />Schwartzwalder Mine File No. M-1977-300 <br />F) Section 15(b)(v) Strategically Designed and Constructed Wetlands <br />(1) On page 15-13 the EPP states that the wetland will create a reducing aquatic environment that <br />will capture and immobilize uranium and molybdenum. As the Operator's intent is to utilize the <br />AFA as a capture facility for potential leakage from the mine pool, and as the mine pool contains <br />constituents other than uranium and molybdenum that are elevated to undesirable concentrations <br />and may include a combination of cationic and anionic species, please comment (and provide <br />specifications if available) on the ability of the wetland to capture additional constituents that will <br />report to the wetland in the event of mine pool leakage. <br />(2) On page 15-13 the EPP states that the wetland would be designed to ensure adequate residence <br />time for ground water that enters the wetland to undergo geochemical processes. Please provide a <br />statement that the design will include an evaluation of historical ground water flow conditions in the <br />AFA, how the system will respond to seasonal fluctuations of high magnitude, how it will respond <br />to extended wet or dry periods, and what level of increased operational oversight will be needed <br />during such times. <br />(3) On page 15-14 the EPP states that monitoring would be performed for up to 10 years to <br />demonstrate that the wetlands are functioning as designed. If a wetland and PRB are ultimately <br />chosen as preferred mitigation options, the operator will not be released from monitoring after 10 <br />years. The operator must provide a commitment to monitor the site for as long as is needed to <br />ensure protection of human health, property, and the environment. <br />G) Section 15(c) Monitoring well installation <br />(1) The monitoring wells were originally scheduled for installation in 2010. Please provide a <br />revised schedule for completion of these two monitoring wells. <br />(2) On page 15-16 the EPP states that water quality sampling "could also be performed" in the <br />proposed monitoring wells. The Operator must commit to quarterly water quality monitoring of the <br />wells, for the standard monitoring well analytical suite that is already in place, until notified <br />otherwise by DRMS. <br />H) Section 15(d) Schedule for Engineering Design, Construction, and Mitigation. Please submit a <br />revised schedule that reflects the current conditions at the site and state of progress of the EPP. <br />I) The EPP contains no provision for mine pool management other than to ignore it. It appears to be <br />the Operator's intention to use the underground workings as a geologic containment facility for the <br />mine pool water. The mine pool water is contaminated with elevated concentrations of uranium, <br />radium and other constituents as a result of disturbance of toxic material in the underground mine. The <br />Division therefore considers the flooded mine workings to be an impoundment under Hardrock Rule <br />6.4.21(1)(c), and subject to the regulations thereto. The Board and Division also consider the mine pool <br />to be a threat to human health, property, and the environment due to the risk of offsite excursions. <br />Therefore, in addition to the Board ordered actions described above in adequacy items 1.A and 1.13, <br />Cotter must also proceed with the activities described in adequacy items 3, 4, and S.B.