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,_ .Roadside ~1inc Reclamation Issues
<br />November 8, 2GOG
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<br />On August 3I, 2000, Dan Mathews and f met with Tonya Hammond and you on-site, to discuss certain reclamation
<br />issues. With respect to CRDA-2 reclamation, we recommended the ,grading plan for the top of the pile be amended to
<br />include a substantial topographic barrier to intercept floodwater and debris flow, and divert such flow away from the
<br />long, steep refuse outslopes, should the proposed upland diversion ditch fail. Final recommendations regarding the
<br />Coal Creek channel and culvert reclamation were no[ made, pending further discussion with BLM. On September 8,
<br />2000, [met with Bruce Fowler and Jim Scheidt of BLM, and again visited the site. A summary of my observations
<br />and discussions with the BLM representatives is provided in a memorandum of September 21, 2000, a copy of which
<br />was sent to you. The memorandum includes detailed recommendations regarding final reclamation designs for the
<br />permanent channel and culvert structures.
<br />On November 3, 2000, DMG received from Powderhom amended reclamation plans addressing deficiencies
<br />identified and recommendations made by DMG, and those plans are cturently under review.
<br />Technical Revision fTR) 33: South Mine Permanent De-waterine PI
<br />During Permit Renewal RN-03 review in 1998 and 1999, the Division identified a deficienry with regard to the
<br />adequacy of the South Mine de-watering system, for the long term (i.e. permanent) post-mining situation. The
<br />primary component of the de-watering plan is a 6 inch pipe siphon system, which outlets through the "Northwest
<br />Intake Portal", an av shaft which was backfilled in the eazly 1990's. In order for the siphon to fanction properly,
<br />perpetual monitoring of the water level in the mine is required. If the siphon does no[ function properly, water levels
<br />would rise to the level of the backfilled Northwest Intake portal, h7tely resulting in uncontrolled discharge, with the
<br />possibility of a catastrophic "blowout" that could create a hazard on Interstate Highway 70, located adjacent w and
<br />down-gradient from the portal.
<br />DMG requested are operator to provide perdnen[ information regarding hydrologic conditions and are existing
<br />discharge system, as well as proposed modifications to address permanent discharge, in adequacy review letters dated
<br />February 12, 1998, April 14, 1999, and December 3, 1999. in response to the Division's concern, ate operator
<br />provided are requested hydrologic information and details of the existing discharge system, and committed within the
<br />permit, to submit plains for a permanent mine-water discharge plan by June 30, 2000. In a letter of February 17, 2000,
<br />the Division directed the operator to submit a minor revision application "interim minewazer discharge plan" and a
<br />technical revision "permanent minewater discharge plan". The permanent plan was to include, in addition to other
<br />items, a description of the worst case consequences of failure. The interim plan, submitted as Minor Revision (MR)
<br />4l, provided for installarion of an additional 4 inch de-watering pipe through the South Portal seals, upgradient of the
<br />Northwest Intake portal. The MR~I plan was approved and implemented, and results in approximately 75 gpm of
<br />mine inflow being intercepted and discharged via an approved discharge location, rather than pooling at the lowest
<br />elevations in the mine. This additional 4 inch pipe supplements the siphon system, but does not alleviate the
<br />deficiencies of the siphon system as a permanent solution, which are described in the previous paragraph.
<br />Powderhom submitted a proposed permanent minewater discharge plan as TR-33, on June 2I, 2000. The plan as
<br />submitted proposed no modifications to the existing "interim de-watering" system, and did not include an evaluation
<br />of the worst case consequences of Failure, which had been requested by the Division. Due to the lack of the worst
<br />case evaluation, the revision was deemed incomplete by DMG. The revision was subsequently amended, and deemed
<br />complete on July 12, 2000. In an adequacy letter dated September 5, 2000, the Division directed the operator to
<br />provide an amended design which would include provision for a maintenance free de-watering mechanism with
<br />minimal potential for failure. The Division determined the existing de-watering system to be unacceptable due to the
<br />high level of monitoring and maintenance necessary to ensure continued functioning, and the pounrial negative
<br />consequences to public safety and water quality, should the system fail. The operator was requested to submit an
<br />amended plan addressing the identified deficiencies by October 5, 2000. Powderhom has failed to submit an amended
<br />plan, and mutt submit such amended plan by November 30, 2000.
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