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Sedimentation Pond A receives runoff and limited spoil spring discharge from the reclaimed and bond - released
<br />Eckman Park surface -mined areas. The Pond is used as a supplemental water supply for the current mining
<br />operations, for recreation for mine employees (stocked with trout for fishing), and discharge from the Pond
<br />• provides for sustained flows through -out most of the year in Foidel Creek. As an MAHA impoundment, Pond A is
<br />subject to regular monthly inspections, except during the winter months. For the MSHA inspections, the outlet
<br />works and pond embankment are inspected, and any necessary repairs made on a timely basis.
<br />Treatment Facility B receives runoff from the Tipple area, including the Belt - Out -Back (BOB) Stockpile.
<br />Upstream of the treatment facility is a clean -out sump, which captures wash -down flows and sediment from the
<br />Tipple. This sump is cleaned -out periodically throughout the year. The treatment facility itself is comprised of an
<br />H shaped pond, which discharges to Foidel Creek. TCC will survey the facility every three years, with the date of
<br />the 1999 Permit Renewal being year one. Therefore, the survey will be conducted during 2001. The survey will be
<br />used to determine if sediment removal is required, with the criteria that sediment accumulation increased by 40
<br />percent from the prior survey. If sediment removal is required, the dredged material will be brought to the refuse
<br />pile or pit for disposal. During CDPS field monitoring, the Facility B flume will be visually inspected to determine
<br />that it is working correctly. Repairs, such as leveling, assuring free discharge, and removal of accumulated
<br />sediment in measuring devices will be done on an as- needed basis. The facility will be removed when it is no
<br />longer needed. The H shaped pond will be backfilled with material from adjacent areas, graded to blend with the
<br />surrounding terrain, topsoiled, and revegetated.
<br />Sedimentation Pond C controls runoff from the old Train Loadout area, which has been converted to the Truck
<br />Loadout. Historically, the pond has discharged infrequently, and holds only a very limited amount of water during
<br />spring runoff. TCC will survey the pond per the schedule for Treatment Facility B. The same criteria will be used
<br />to determine if the pond requires cleaning. If so, the material will be removed and hauled to the refuse pile or pit
<br />for disposal. During the quarterly pond inspection, the outlet works of Pond C are inspected to determine if any
<br />maintenance work is required. Any required maintenance work is noted and completed within a reasonable time
<br />period following the inspection. When the pond is longer needed it will be removed. The outlet works will be
<br />• removed, the embankment pushed in and graded to blend with the 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, minor amounts of underground mine discharge (also from the Area 1 Pit), and will
<br />receive and control discharge from a temporary Water Treatment Pilot Installation during a brief test period. In
<br />general, because the Area 1 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. During Permit Renewal 3, TCC contracted with Montgomery Watson to review the design
<br />of Pond D. The resulting design review report is provided in Exhibit 8H(1). At one point in time, an aerator was
<br />installed in Pond D to promote aerobic conditions throughout the year. There is an existing powerline and power -
<br />box on the west side of the pond. The aerator and power supply will be removed prior to reclamation of the pond.
<br />With construction and initiation of operations for Washplant II, process water withdrawals from the Area 1 Pit for
<br />the Washplant have been balanced with inputs to meet process demands and maintain a stable water level in the Pit
<br />(well below the maximum design water level). The Washplant II construction encroached on the Pond D
<br />emergency spillway, so the spillway was relocated to a location near the principal spillway riser on the Pond
<br />embankment. Spillway dimensions and configuration were preserved, and the new spillway location provides for
<br />better routing through the pond, increasing the distance between the eastern pond inlet and the spillway.
<br />TCC will survey Pond D per the previously outlined schedule. The same criteria will be used to determine if the
<br />pond requires cleaning. If so, the material will be removed and hauled to the refuse pile or pit for disposal. The
<br />pond is inspected during the regular CDPS sampling and the flume is checked to determine if it is functioning
<br />correctly. Any problems are noted and repairs made as- needed. Pond D is also an MSHA pond, subject to regular
<br />monthly inspections, except during the winter months. For the MSHA inspections, the outlet works and pond
<br />embankment are inspected, and any necessary repairs made in a timely basis. The pond will be removed when it is
<br />• no longer needed. . The outlet works will be removed, the rock in the emergency spillway may be reclaimed or
<br />placed in the pond basin, the embankment will be pushed in and graded to blend with the surrounding terrain, and
<br />the area will be topsoiled and revegetated.
<br />MR09 -239 2.05 -77 09/24/09
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