Wyoming Administrative Code › Agency 053 - Workforce Services, Department of › Sub-Agency 0004 - Mining Inspector › Chapter 5 - SURFACE COAL MINES › Subpart C - Surface Installations › Section 77.216-2 - Water, sediment, or slurry impoundment and impounding structures; minimum plan requirements; change or modifications; certification

Current through July 13, 2024
(a) The plan specified in S 77.216, shall
				  contain as a minimum the following information:
(1) The name and address of the persons
				  owning, operating or controlling the impoundment or impounding structure; the
				  name associated with the impoundment or impounding structure; the
				  identification number of the impounding structure as assigned by the District
				  Manager; and the identification number of the mine or preparation plant as
				  assigned by MSHA.
(2) The location
				  of the structure indicated on the most recent USGS 7 1/2 minute or 15 minute
				  topographic quadrangle map, or a topographic map of equivalent scale if a USGS
				  map is not available.
(3) A
				  statement of the purpose for which the structure is or will be used.
(4) The name and size in acres of the
				  watershed affecting the impoundment.
(5) A description of the physical and
				  engineering properties of the foundation materials on which the structure is or
				  will be constructed.
(6) A
				  statement of the type, size, range, and physical and engineering properties of
				  the materials used, or to be used, in constructing each zone or stage of the
				  impounding structure; the method of site preparation and construction of each
				  zone; the approximate dates of construction of the structure and each
				  successive stage; and for existing structures, such history of construction as
				  may be available, and any record or knowledge of structural
				  instability.
(7) At a scale not to
				  exceed 1 inch=100 feet, detailed dimensional drawings of the impounding
				  structure including a plan view and cross sections of the length and width of
				  the impounding structure, showing all zones, foundation improvements, drainage
				  provisions, spillways, diversion ditches, outlets, instrument locations, and
				  slope protection, in addition to the measurement of the minimum vertical
				  distance between the crest of the impounding structure and the reservoir
				  surface at present and under design storm conditions, sediment or slurry level,
				  water level and other information pertinent to the impoundment itself,
				  including any identifiable natural or manmade features which could affect
				  operation of the impoundment.
(8) A
				  description of the type and purpose of existing or proposed
				  instrumentation.
(9) Graphs showing
				  area-capacity curves.
(10) A
				  statement of the runoff attributable to the probable maximum precipitation of
				  6-hour duration and the calculations used in determining such runoff.
(11) A statement of the runoff attributable
				  to the storm for which the structure is designed and the calculations used in
				  determining such runoff.
(12) A
				  description of the spillway and diversion design features and capacities and
				  calculations used in their determination.
(13) The computed minimum factor of safety
				  range for the slope stability of the impounding structure including methods and
				  calculations used to determine each factor of safety.
(14) The locations of surface and underground
				  coal mine workings including the depth and extent of such workings within the
				  area 500 feet around the perimeter, shown at a scale not to exceed one inch=500
				  feet.
(15) Provisions for
				  construction surveillance, maintenance, and repair of the impounding
				  structure.
(16) General provisions
				  for abandonment.
(17) A
				  certification by a registered engineer that the design of the impounding
				  structure is in accordance with current, prudent engineering practices for the
				  maximum volume of water, sediment, or slurry which can be impounded therein and
				  for the passage of runoff from the designed storm which exceeds the capacity of
				  the impoundment; or, in lieu of the certification, a report indicating what
				  additional investigations, analyses, or improvement work are necessary before
				  such a certification can be made, including what provisions have been made to
				  carry out such work in addition to a schedule for completion of such
				  work.
(18) Such other information
				  pertaining to the stability of the impoundment and impounding structure which
				  may be required by the District Manager.