(a) Alluvial valley floor determination.
  (1) Before applying for a permit to conduct, or before conducting surface coal mining and reclamation operations within a valley holding a stream or in a location where the adjacent area includes any stream in the arid or semiarid regions of the United States, the applicant shall either affirmatively demonstrate, based on available data, the presence of an alluvial valley floor, or submit to the Commission the results of a field investigation of the proposed permit area and adjacent area. The field investigations shall include sufficiently detailed geologic, hydrologic, land-use, soils, and vegetation studies on areas required to be investigated by the Commission, after consultation with the applicant, to enable the Commission to make an evaluation regarding the existence of the probable alluvial valley floor in the proposed permit area or adjacent area and to determine which areas, if any, require more detailed study in order to allow the Commission to make a final determination regarding the existence of an alluvial valley floor. Studies performed during the investigation by the applicant or subsequent studies as required of the applicant by the Commission, shall include an appropriate combination, adapted to site-specific conditions, of:
    (A) mapping of unconsolidated stream-laid deposits holding streams including, but not limited to, geologic maps of unconsolidated deposits and stream-laid deposits, maps of stream delineation of surface watersheds and directions of shallow ground-water flows through and into the unconsolidated deposits, topography showing local and regional terrace levels, and topography of terraces, flood plains and channels showing surface drainage patterns;
    (B) mapping of all lands included in the area in accordance with this paragraph and subject to agricultural activities, showing the area in which different types of agricultural lands, such as flood irrigated lands, pasture lands and undeveloped rangelands, exist, and accompanied by measurements of vegetation in terms of productivity and type;
    (C) mapping of all lands that are currently or were historically flood irrigated, showing the location of each diversion structure, ditch, dam and related reservoir, irrigated land, and topography of those lands;
    (D) documentation that areas identified in this paragraph are, or are not, subirrigated, based on ground-water monitoring data, representative water-quality soil-moisture measurements, and measurements of rooting depth, soil mottling, and water requirements of vegetation;
    (E) documentation, based on representative sampling, that areas identified under this paragraph are, or are not, flood irrigable, based on streamflow, water quality, water yield, soil measurements, and topographic characteristics; and
    (F) analysis of a series of aerial photographs, including color infrared imagery flown at a time of year to show any late summer and fall differences between upland and valley floor vegetative growth and of a scale adequate for reconnaissance identification of areas that may be alluvial valley floors.
  (2) Based on the investigations conducted under paragraph (1) of this subsection, the Commission shall make a determination of the extent of any alluvial valley floors within the study area and whether any stream in the study area may be excluded from further consideration as lying within an alluvial valley floor. The Commission shall determine that an alluvial valley floor exists if it finds that:
    (A) unconsolidated stream-laid deposits holding streams are present; and
    (B) there is sufficient water to support agricultural activities as evidenced by:
      (i) the existence of flood irrigation in the area in question or its historical use;
      (ii) the capability of an area to be flood irrigated, based on stream-flow water yield, soils, water quality, and topography; or
      (iii) subirrigation of the lands in question, derived from the ground-water system of the valley floor.
(b) Application contents for operations affecting designated alluvial valley floors.
  (1) If land within the proposed permit area or adjacent area is identified as an alluvial valley floor and the proposed mining operation may affect an alluvial valley floor or waters that supply alluvial valley floors, the applicant shall submit a complete application for the proposed mining and reclamation operations, to be used by the Commission, together with other relevant information, including the information required by subsection (a) of this section, as a basis for approval or denial of the permit. The complete application shall include detailed surveys and baseline data required by the Commission for a determination of:
    (A) the essential hydrologic functions of the alluvial valley floor which might be affected by the mining and reclamation process;
    (B) the significance of the area to be affected to agricultural activities;
    (C) whether the operation will cause, or presents an unacceptable risk of causing, material damage to the quantity or quality of surface or ground waters that supply the alluvial valley floor;
    (D) the effectiveness of proposed reclamation with respect to requirements of the Act and this chapter (relating to Coal Mining Regulations); and
    (E) specific environmental monitoring required to measure compliance with §§12.610-12.613 of this title (relating to Alluvial Valley Floors: Monitoring) during and after mining and reclamation operations.
  (2) Information required under this subsection shall include, but not be limited to:
    (A) geologic data, including geologic structure, surficial geologic maps, and geologic cross-sections;
    (B) soils and vegetation data, including a detailed soil survey and chemical and physical analyses of soils, a vegetation map and narrative descriptions of quantitative and qualitative surveys, and land-use data, including an evaluation of crop yields;
    (C) surveys and data required under this subsection for areas designated as alluvial valley floors because of their flood irrigation characteristics shall also include, at a minimum, surface hydrologic data, including streamflow runoff, sediment yield, and water-quality analyses describing seasonal variations over at least 1 full year, field geomorphic surveys and other geomorphic studies;
    (D) surveys and data required under this subsection for areas designated as alluvial valley floors because of their subirrigation characteristics, shall also include, at a minimum, geohydrologic data including observation well establishment for purposes of water-level measurements, ground-water contour maps, testing to determine aquifer characteristics that affect waters supplying the alluvial valley floors, well and spring inventories, and water-quality analyses describing seasonal variations over at least 1 full year, and physical and chemical analysis of overburden to determine the effect of the proposed mining and reclamation operations on water quality and quantity;
    (E) plans showing how the operation will avoid, during mining and reclamation, interruption, discontinuance or preclusion of farming on the alluvial valley floors unless the premining land use has been undeveloped rangeland which is not significant to farming and will not materially damage the quantity or quality of water in surface- and ground-water systems that supply alluvial valley floors;
    (F) maps showing farms that could be affected by the mining and, if any farm includes an alluvial valley floor, statements of the type and quantity of agricultural activity performed on the alluvial valley floor and its relationship to the farm's total agricultural activity including an economic analysis; and
    (G) such other data as the Commission may require.
  (3) The information required by paragraph (1) of this subsection shall evaluate those factors which contribute to the collecting, storing, regulating and making natural flow of water available for agricultural activities on the alluvial valley floor and shall include, but not be limited to:
    (A) factors contributing to the function of collecting water which include, but are not limited to:
      (i) the amount and rate of runoff and a water balance analysis, with respect to rainfall, evapotranspiration, infiltration and ground-water recharge;
      (ii) the relief, slope, and density of the network of drainage channels;
      (iii) the infiltration, permeability, porosity and transmissivity of unconsolidated deposits of the valley floor that either constitute the aquifer associated with the stream or lie between the aquifer and the stream; and
      (iv) other factors that affect the interchange of water between surface streams and ground-water systems, including the depth to ground water, the direction of ground-water flow, the extent to which the stream and associated alluvial ground-water aquifers provide recharge to, or are recharged by, bedrock aquifers;
    (B) factors contributing to the function of storing water which include, but are not limited to:
      (i) surface roughness, slope, and vegetation of the channel, floodplain, and low terraces that retard the flow of surface waters;
Cont'd...