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Impoundments

SMCRA requires that permanent impoundments of water on mining sites are to be authorized in the approved mining and reclamation plan and permit, as part of the reclamation activities only when it is adequately demonstrated that:

  1. the size of the impoundment is adequate for its intended purposes; and
  2. the impoundment dam construction will be so designed as to achieve necessary stability with an adequate margin of safety compatible with that of structures constructed under Public Law 83-566 (16 U.S.C. 1006).
Aerial view of a coal waste impoundment.
Aerial view of a coal waste impoundment.

Coal waste is produced during the cleaning of coal for market, and usually occurs at “coal preparation plants.” This process produces coarse (usually 6-inch or smaller material) and fine coal waste. Impoundments are embankments are constructed for the permanent disposal of waste coal, rock, and related mining by-product materials. 

Impoundments are constructed by building a retaining embankment with coarse coal waste across a valley to create a fine coal waste collection basin. The water transporting the fine coal slurry is often decanted from the top of the impoundment and repeatedly recycled to the preparation facility to “wash” more coal.

These structures are subject to the regulatory requirements of OSMRE and the Mine Health and Safety Administration (MSHA). These regulatory programs complement each other: with the intent of MSHA to provide for the health and safety of miners and the intent of OSMRE to protect the public and to limit environmental effects. To uphold these requirements,  OSMRE conducts evaluations and provides regulatory guidance for inspections, oversight, citizen complaint investigations, MSHA coordination, and program amendments. 

A coal mine waste slurry impoundment in DOI Region 1.
A coal mine waste slurry impoundment in DOI Region 1.