Texas Administrative Code › Title 16 - ECONOMIC REGULATION › Part 1 - RAILROAD COMMISSION OF TEXAS › Chapter 12 - COAL MINING REGULATIONS › Subchapter K - PERMANENT PROGRAM PERFORMANCE STANDARDS › Division 2 - PERMANENT PROGRAM PERFORMANCE STANDARDS - SURFACE MINING ACTIVITIES › Section 12.365 - Disposal of Excess Spoil: Head-of-Hollow Fills

Current through Reg. 49, No. 28; July 12, 2024
(a) Disposal of spoil in the head-of-hollow
					 fill shall meet all standards set forth in §§
											RSA
					 12.363 and
					 RSA
					 12.364 of this title (relating to Disposal of
					 Excess Spoil: General Requirements, and to Disposal of Excess Spoil: Valley
					 Fills) and the additional requirements of this section.
(b) The fill shall be designed to completely
					 fill the disposal site to the approximate elevation of the ridgeline. A
					 rock-core chimney drain may be utilized instead of the subdrain and surface
					 diversion system required for valley fills. If the crest of the fill is not
					 approximately at the same elevation as the low point of the adjacent ridgeline,
					 the fill must be designed as specified in §
											RSA
					 12.364 of this title (relating to Disposal of
					 Excess Spoil: Valley Fills) with diversion of runoff around the fill. A fill
					 associated with contour mining and placed at or near the coal seam, and which
					 does not exceed 250,000 cubic yards, may use the rock-core chimney
					 drain.
(c) The alternative
					 rock-core chimney-drain system shall be designed and incorporated into the
					 construction of head-of-hollow fills as follows:
(1) the fill shall have, along the vertical
					 projection of the main buried stream channel or rill a vertical core of durable
					 rock at least 16 feet thick which shall extend from the toe of the fill to the
					 head of the fill, and from the base of the fill to the surface of the fill. A
					 system of lateral rock underdrains shall connect this rock core to each area of
					 potential drainage or seepage in the disposal area. Rocks used in the rock core
					 and underdrains shall meet the requirements of §
												RSA
					 12.364<subdiv>(c)</subdiv> of
					 this title (relating to Disposal of Excess Spoil: Valley Fills);
(2) a filter system to ensure the proper
					 functioning of the rock core shall be designed and constructed using standard
					 geotechnical engineering methods; and
(3) the grading may drain surface water away
					 from the outslope of the fill and toward the rock core. The maximum slope of
					 the top of the fill shall be 33h:1v (3%). Instead of the requirements of §
												RSA
					 12.363<subdiv>(g)</subdiv> of
					 this title (relating to Disposal of Excess Spoil: General Requirements), a
					 drainage pocket may be maintained at the head of the fill during and after
					 construction, to intercept surface runoff and discharge the runoff through or
					 over the rock drain, if stability of the fill is not impaired. In no case shall
					 this pocket or sump have a potential for impounding more than 10,000 cubic feet
					 of water. Terraces on the fill shall be graded with a 3.0 to 5.0% grade toward
					 the fill and a 1.0% slope toward the rock core.