(a) Cover.
  (1) A person who conducts underground mining activities shall cover, with a minimum of 4 feet of the best available non-toxic and non-combustible material, all exposed coal seams remaining after mining and all acid-forming materials, toxic-forming materials, combustible materials, or any other materials identified by the Commission as exposed, used, or produced during mining.
  (2) If necessary, these materials shall be treated to neutralize toxicity, in order to prevent water pollution and sustained combustion and minimize adverse effects on plant growth and land uses.
  (3) Where necessary to protect against upward migration of salts, exposure by erosion, to provide an adequate depth for plant growth, or to otherwise meet local conditions, the Commission shall specify thicker amounts of cover using non-toxic material.
  (4) Acid-forming or toxic-forming material shall not be buried or stored in proximity to a drainage course so as to cause or pose a threat of water pollution.
(b) Stabilization. Backfilled material shall be selectively hauled or conveyed and compacted, wherever necessary to prevent leaching of acid-forming and toxic-forming materials into surface or ground waters and wherever necessary to ensure the stability of backfilled materials. The method and design specifications of compacting material shall be approved by the Commission before acid-forming and toxic-forming materials are covered.

Source Note: The provisions of this §12.553 adopted to be effective April 7, 1997, 22 TexReg 3093.