2012-10-01_REVISION - M1977306 (20)

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requirements, the flow rate will be measured and monitored at the discharge point of the treated water ponds. The water treatment building is located immediately south of the old treated water ponds. The building is used for storage for barium chloride solution, anionic polymer flocculant and a peristaltic chemical pump that is used to combine the reagents and mine water before pumping into the treated water ponds. Up to 100 lbs of barium chloride and 50 lbs of flocculant will be kept onsite at all times. The treatment building has a concrete floor with a 6 inch berm to contain spills of up to 500 gallons. A small ( -1.5 ft x 1.5 ft) sump is also present in the treatment building. The building's chemical pump and an underground main pump are connected electrically. In that configuration the underground pump will operate only when the chemical pump is also operating. The system is checked on a regular basis when in operation. The underground pump is on a float within one of two in- series sumps in the mine workings. Each of these sumps has a capacity of 36,000 gallons. If there is a malfunction of the chemical pump or a lack of reagents, the mine pump will shut down. Treated Water Ponds Two settling ponds have been constructed to the northwest of the water treatment building as part of the previous amendment. These ponds are designed to replace the older ponds. The first pond (Small Pond) has a capacity of roughly 11,600 cubic feet (— 72,200 gallons) and the second pond (Large Pond) has roughly a 52,800 cubic foot (— 328,000 gallon) capacity. Based on past mine pumping rates, these ponds have sufficient capacity to provide adequate treatment for future mine operation. Treated water will travel from the treatment building to the Small Pond via a 6 inch HDPE pipe. Initial settling of precipitate will begin in the Small Pond. A gravity flow pipe connecting the two ponds will carry water from the Small Pond into the Large Pond where the remaining precipitate will settle over a longer period of time. At the southwest corner of the Large Pond, a 4 inch steel discharge pipe, located 2 feet from the top of pond, will carry the treated water to the weir measuring point. Samples of the discharge will be taken at this point. The weir leads to a second 4 inch steel pipe which will extend at the top of the Mesa. From there, a 2 inch HDPE pipe will deliver the water to an area below the mine sediment pond. The treated water ponds will be lined with a DRMS approved liner system installed by a certified liner company. Table D -1 shows the type of liners to be used.