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treatment facilities are similar, including quarterly pond inspections, however, specific details relative to each are
<br />described separately in the following sections.
<br />Sedimentation Pond A was constructed and utilized as the main downgradient sedimentation control structure for
<br />the previous surface mining operations in Eckman Park. Design information for Pond A is provided in Exhibits 13
<br />and 14 of Permit C-81-071 and in Exhibit 8H, Hydrologic Evaluation of Sedimentation Ponds A, D and G. Pond A
<br />has been approved for retention as a permanent impoundment.
<br />Treatment Facility B receives runoff from the Tipple area, including the Belt -Out -Back (BOB) Stockpile. Design
<br />information for Pond B is provided in Exhibit 8F, CYCC Pond B — Stage -Storage. Upstream of the treatment
<br />facility is a clean-out sump, which captures wash -down flows and sediment from the Tipple. This sump is cleaned -
<br />out on an as -needed basis, based on visual observation of sediment accumulations. The treatment facility itself is
<br />comprised of an H shaped pond, which discharges to Foidel Creek. TC visually evaluates the extent of sediment
<br />accumulating as a delta in the inlet area in late summer or early fall, when water levels are at their lowest and the
<br />inlet area is exposed. If significant sediment has accumulated, to the extent that facility function or capacity would
<br />be reduced, sediment removal is scheduled and conducted using a long -reach backhoe, with the dredged material
<br />being loaded into trucks and transported to the refuse pile for disposal. During CPDES field monitoring, the
<br />Facility B flume is visually inspected to determine that it is working correctly. Repairs, such as leveling, assuring
<br />free discharge, and removal of accumulated sediment in measuring devices is done on an as -needed basis. The
<br />facility will be removed when it is no longer needed. The H shaped pond will be backfilled with material from
<br />adjacent areas, graded to blend with the surrounding terrain, topsoiled, and revegetated.
<br />The Sedimentation Pond C structure controls runoff from the old Train Loadout area, which has been converted to
<br />the Truck Loadout. Design information for Pond C is provided in Exhibit 8G, Sedimentation Pond C — Design and
<br />Certification. Historically, the pond has discharged infrequently, and holds only a very limited amount of water
<br />during spring runoff. TC will inspect Pond C for sediment accumulations in the same manner as described for
<br />Treatment Facility B. The same criteria will be used to determine if the pond requires cleaning. If so, the material
<br />will be removed and hauled to the refuse pile or pit for disposal. During the quarterly pond inspection, the outlet
<br />works of Pond C are inspected to determine if any maintenance work is required. Any required maintenance work
<br />is noted and completed within a reasonable time period following the inspection. When the pond is longer needed
<br />it will be removed. The outlet works will be removed, the embankment pushed in and graded to blend with the
<br />surrounding terrain, topsoiled, and revegetated.
<br />Sedimentation Pond D controls runoff from a portion of the surface facilities area, discharge from the Area 1 Pit,
<br />runoff from the Refuse Pile, and minor amounts of underground mine discharge (also from the Area I Pit). Design
<br />information for Pond D is provided in Exhibits 13 and 14 of Permit C-81-071 and in Exhibits 8H, 8H1 and 81-12. In
<br />general, because the Area l Pit is part of the mine -water collection and recycle system, discharge from the Area 1
<br />Pit or underground mine discharge occurs rarely, if ever, since process water demand equals or exceeds normal
<br />flows to the Area 1 Pit. With construction and initiation of operations for Washplant II, process water withdrawals
<br />from the Area 1 Pit for the Washplant have been balanced with inputs to meet process demands and maintain a
<br />stable water level in the Pit (well below the maximum design water level). The Washplant Ii construction
<br />encroached on the Pond D emergency spillway, so the spillway was relocated to a location near the principal
<br />spillway riser on the Pond embankment. Spillway dimensions and configuration were preserved, and the new
<br />spillway location provides for better routing through the pond, increasing the distance between the eastern pond
<br />inlet and the spillway.
<br />TC will inspect Pond D for sediment accumulations in the same manner as described for Treatment Facility B. The
<br />same criteria will be used to determine if the pond requires cleaning. If so, the material will be removed and hauled
<br />to the refuse pile or pit for disposal. The pond is inspected during the regular CPDES sampling and the flume is
<br />checked to determine if it is functioning correctly. Any problems are noted and repairs made as -needed. Pond D is
<br />also an MSHA pond, subject to regular monthly inspections, except during the winter months. For the MSHA
<br />inspections, the outlet works and pond embankment are inspected, and any necessary repairs made in a timely
<br />basis. The pond will be removed when it is no longer needed. The outlet works will be removed, the rock in the
<br />emergency spillway may be reclaimed or placed in the pond basin, the embankment will be pushed in and graded to
<br />blend with the surrounding terrain, and the area will be topsoiled and revegetated.
<br />RN 17-07 2.05-76.1 02/15/18
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