1995-08-11_REVISION - M1977493 (9)

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followed by the capping and revegetation of the No. 1 Dam and capping the Robinson tailing impoundment flats. All dry and accessible beach areas on the Robinson impoundment were capped in 1994. Thus, only the Ten Mile impoundment and No. 3 Dam remain for interim dust control. The EPF for controlling and suppressing fugitive dust from the tailing impoundment is Coherex. Coherex is an industry standard, biodegradable, hydrocarbon-based suppressant which consists of 50 percent petroleum resins and 40 percent wetting solution. The solution is mixed at a ratio of 1 part Coherex to 9 parts water and is applied either with a 3000 gallon capacity TRYCO balloon tired vehicle or a 2800 gallon Terragator vehicle. Coherex is applied once per year when the susceptible sites begin to dry following snow melt and on a "spot" basis as needed. Coherex is stored in a 10,000 gallon tank at the Coherex fill station located near the Ten Mile Barge at the southwest end of the Ten Mile tailing impoundment. This tank is fully contained by an earthen berm with the capacity to contain 120 percent of the tank capacity. Other points where fugitive dust from ore material can be released into the environment during periods of active operation are at the primary crushing and ore conveying systems at the crusher house. Dust control for the crushing and conveying system utilizes Ducon UW-IV-120 scrubbers, Rotoclones, and Flex Clean baghouses. Dust collection starts in the dump pocket with a 144", 250 hp unit and follows the travel of the ore up,the conveyor to the drive house and head house using 100 hp units. The conveying systems beneath the ore storage piles use 50 hp drive units. As noted in Section 2.2, all release points in the crushing/conveying/milling process are permitted by the CDPHE, Air Pollution Control Division. Under drying and windy conditions during active operations, dust also may be released from the pit area, haul roads, yard areas, and any unpaved roads on the site. Dust suppression on these areas utilizes standard water trucks to keep those sites wetted. However, during inactive periods, dust suppression at these locations becomes moot. 5.4 Environmental Protection Facility Effectiveness Evaluation The EPFs described and discussed for the three watersheds at the Climax Mine site have been very effective in preventing releases of potential contaminants to the environment. Indeed, there have been no regulatory violations in the last 6 years at the site. Since 1985, Climax received two Notices of Violation(NoV); a tailing dust NoV in 1986, and a minor spill NoV in 1988 for a non- designated substance. The Climax Mine has an excellent record of environmental regulatory compliance. 29