(a) General. Each application shall include a general plan for each proposed sedimentation pond, water impoundment, and coal processing waste bank, dam, or embankment within the proposed permit area.      
        (1) Each general plan shall:                  (A) be prepared by or under the direction of, and certified by a qualified professional engineer, or by a qualified professional geoscientist, with assistance from experts in related fields such as land surveying and landscape architecture;                   (B) contain a description, map, and cross section of the structure and its location;                   (C) contain preliminary hydrologic and geologic information required to assess the hydrologic impact of the structure;                   (D) contain 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; and                   (E) contain a certification statement which includes a schedule setting forth the dates that any detailed design plans for structures that are not submitted with the general plan will be submitted to the Commission. The Commission shall have approved, in writing, the detailed design plan for a structure before construction of the structure begins.         
        (2) Each detailed design plan for a structure that meets or exceeds the size or other criteria of the Mine Safety and Health Administration, 30 CFR 77.216(a), shall:                  (A) be prepared by or under the direction of, and certified by a qualified professional engineer with assistance from experts in related fields such as geology, land surveying, and landscape architecture;                   (B) include any geotechnical investigation, design, and construction requirements for the structure;                   (C) describe the operation and maintenance requirements for each structure; and                   (D) describe the timetable and plans to remove each structure, if appropriate.         
        (3) Each detailed design plan for a structure that does not meet the size or other criteria of 30 CFR 77.216(a) shall:                  (A) be prepared by or under the direction of, and certified by a qualified professional engineer;                   (B) include any design and construction requirements for the structure, including any required geotechnical information;                   (C) describe the operation and maintenance requirements for each structure; and                   (D) describe the timetable and plans to remove each structure, if appropriate.         
      (b) Sedimentation ponds. Sedimentation ponds, whether temporary or permanent, shall be designed in compliance with the requirements of §12.344 of this title (relating to Hydrologic Balance: Sedimentation Ponds). Any sedimentation pond or earthen structure which will remain in the proposed permit area as a permanent water impoundment shall also be designed to comply with the requirements of §12.347 of this title (relating to Hydrologic Balance: Permanent and Temporary Impoundments). Each plan shall, at a minimum, comply with the requirements of the Mine Safety and Health Administration, 30 CFR 77.216-1 and 77.216-2.     
      (c) Permanent and temporary impoundments.      
        (1) Permanent and temporary impoundments shall be designed to comply with the requirements of §12.347 of this title (relating to Hydrologic Balance: Permanent and Temporary Impoundments).       
        (2) Each plan for an impoundment meeting the size or other criteria of the Mine Safety and Health Administration shall comply with the requirements of 30 CFR 77.216-1 and 30 CFR 77.216-2. The plan required to be submitted to the District Manager of MSHA under 30 CFR 77.216 shall be submitted to the Commission as part of the permit application in accordance with subsection (a) of this section.       
        (3) An impoundment not meeting the size or other criteria applicable under §12.347(a) of this title (relating to Hydrologic Balance: Permanent and Temporary Impoundments) shall have a minimum static safety factor of 1.3 for a normal pool with steady state seepage saturation conditions.       
      (d) Coal processing waste banks. Coal processing waste banks shall be designed to comply with the requirements of §§12.368-12.371 of this title (relating to Coal Processing Waste Banks: General Requirements, to Coal Processing Waste Banks: Site Inspection, to Coal Processing Waste Banks: Water Control Measures, and to Coal Processing Waste Banks: Construction Requirements).     
      (e) Coal processing waste dams and embankments. Coal mine waste dams and embankments shall be designed to comply with the requirements of §§12.376 - 12.378 of this title (relating to Coal Mine Waste: Dams and Embankments: General Requirements, to Coal Mine Waste: Dams and Embankments: Site Preparation, and to Coal Mine Waste: Dams and Embankments: Design and Construction). Each plan shall comply with the requirements of the Mine Safety and Health Administration, 30 CFR 77.216-1 and 77.216-2, and shall contain the results of a geotechnical investigation of the proposed dam or embankment foundation area, to determine the structural competence of the foundation which will support the proposed dam or embankment structure and the impounded material. The geotechnical investigation shall be planned and supervised by a qualified professional engineer or qualified professional geoscientist, according to the following:      
        (1) the number, location, and depth of borings and test pits shall be determined using current prudent engineering practice for the size of the dam or embankment, quantity of material to be impounded, and subsurface conditions;       
        (2) the character of the overburden and bedrock, the proposed abutment sites, and any adverse geotechnical conditions which may affect the particular dam, embankment, or reservoir site shall be considered;       
        (3) all springs, seepage, and ground water flow observed or anticipated during wet periods in the area of the proposed dam or embankment shall be identified on each plan; and       
        (4) consideration shall be given to the possibility of mudflows, rock-debris falls, or other landslides into the dam, embankment, or impounded material.       
      (f) Additional requirements. If the structure is 20 feet or higher or impounds more than 20 acre-feet, each plan under subsections (b), (c), and (e) of this section shall include a stability analysis of each structure. The stability analysis shall include, but not be limited to, strength parameters, pore pressures, and long-term seepage conditions. The plan shall also contain a description of each engineering design assumption and calculation with a discussion of each alternative considered in selecting the specific design parameters and construction methods.     
     Source Note:        The provisions of this §12.148 adopted to be effective April 7, 1997, 22 TexReg 3093; amended to be effective November 4, 1997, 22 TexReg 10640; amended to be effective December 28, 2020, 45 TexReg 9503