2008-09-19_PERMIT FILE - C1981018A (11)

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The pipeline was constructed of six-inch diameter pipe approved for use in pressurized potable waterlines by the American Water Works Association (AWWA), the Colorado State Board of Health, an applicable plumbing codes and regulations. The pipeline has a maximum capacity of about 500 gpm. The surface portions of the pipeline were buried five to six feet deep to prevent freezing. The pipe was laid in fine soil bedding in a trench approximately three feet wide. Since the area of disturbance was about four feet wide, topsoil was not removed from the pipe trench area. Some clearing of brush and trees and some minor access road construction was required. All earth disturbances including the pipeline trench were reclaimed and seeded with temporary seeding in the spring of 1986. The water supply pipeline will be left in place after mine operations cease to minimize land disturbance. Minimum lengths of pipeline may be removed if final grading dictates removal. The temporary water pipeline was buried along the toe of the existing county road fill at a depth of approximately six feet. A backhoe was used to dig the trench. A small dozer was used to push approximately one foot of topsoil material to the side in those locations where topsoil exists. By • clearing topsoil ahead of the backhoe all topsoil was salvaged. Upon successful laying and testing of the temporary water line, the overburden was backfilled in the trench and topsoil spread evenly back over the disturbance. Due to extremely harsh weather conditions at the time the topsoil was respread, seeding was not implemented until the spring of 1986, when barley or annual rye was planted as a stubble crop. The permanent mixture was then applied in the fall of 1986. Areas along the pipeline excavation that had no topsoil due to previous disturbances were ripped and seeded. The existing waterline was routed in anon-subsidence corridor, however, due to a change in the mine plan, a part of this corridor subsided but no damage to the waterline was noted. Check valves were installed along the line such that if a breakrn the line occurs the portion of the line containing the break will be isolated and the amount of water lost will be limited to only that portion of the line. The pumps are equipped with pressure sensor switches that will shut the pumps off if a sudden drop in pressure occurs. Thrust cushion blocks will be constructed as necessary. IV.F.2 Water Storaoe Svstem The water storage tank area located above the "D" Portal Area (shown on Map 15 and 52) contains a raw water storage tank, a potable water storage tank, and a potable water treatment building. • Permit Rev. 4 (11/2002) IV-27