Current Regulatory Framework - Coal Waste Impoundments: Risks, Responses, and Alternatives - page 27

below the local water table for at least some part of the year, and obtains its
flow from both surface runoff and groundwater discharge.
Perennial stream means a stream or part of a stream that flows continuously
during all of the calendar year as a result of groundwater discharge or surface
runoff.
Operators permitting a coal waste impoundment that lies within the buffer
zone obtain waivers of this rule by obtaining Section 404 permits from the U.S.
Army Corps of Engineers (see below).
Requirements for Engineering Plans
Impoundments that are constructed of, or that impound, coal waste
materials must comply with the requirements of SMCRA at 30 U.S.C. §§ 1265
(b)(13), 1265(b)(f), and 1266(b)(5), and OSM regulations at 30 C.F.R. §§
780.25, 816.49, 816.81 and 816.84. The rules require the submission of
engineering plans for these impoundments. They also cross-reference the
MSHA requirements for engineering plan content. They specify storm and
freeboard design requirements, as well as minimum safety factors under
reasonably foreseeable site conditions. Requirements for the embankment,
foundation, and abutment conditions are addressed, as are seepage and
allowance for settlement.
OSM regulations (30 C.F.R. § 816.81(d)) require that all applications for
coal mine waste disposal facilities, including all coal waste impoundments,
have a foundation investigation to determine design requirements for
foundation stability. This rule specifically requires that the design include an
analysis of foundation conditions that takes into consideration the effect of
underground mine workings on the stability of the disposal facility. The
regulations at 30 C.F.R. § 780.25 (e) also require that each design plan
submitted for this type of facility include the results of a geotechnical
investigation of the embankment foundation area. Finally, under 30 C.F.R.
§780.25 (a)(1)(iv), each impoundment plan must include a survey describing
the potential effect on the structure from subsidence of the subsurface strata
resulting from past underground mining operations if underground mining has
occurred.