(a) A pre-application determination of the presence or absence of an alluvial valley floor and the applicability of the statutory exclusions of W.S. § 35-11-406(n)(v) may be requested by the applicant and, if requested, shall be made by the Administrator provided sufficient information is submitted. Public notice and opportunity for comment shall be provided during the permit approval process.
(b) All applications for a surface coal mining permit shall contain sufficient information to affirmatively demonstrate the presence or absence of alluvial valley floors within the permit area and on those adjacent areas where an alluvial valley floor containing areas of subirrigation or flood irrigation agricultural activities may reasonably be expected to be affected by the proposed mining operation, including, at a minimum: - (i) Maps of unconsolidated deposits holding streams including, but not limited to, geologic map of unconsolidated deposits and streamlaid deposits, maps of streams, delineation of surface watersheds and acreage, topography, showing terrace levels and conditions, flood plains and channels showing surface drainage patterns.
- (ii) Maps and description of all lands associated with the unconsolidated streamlaid deposits which are subjected to subirrigation or flood irrigation agricultural activities.
- (iii) For the permit area, the application shall include the quantity and quality of surface water available for flood irrigation of unconsolidated streamlaid deposits. The application may include written views of local conservation district personnel concerning the potential for flood irrigation of the unconsolidated streamlaid deposits.
- (iv) Such other information that the Administrator shall require to identify whether an alluvial valley floor exists within the permit area or on adjacent areas and its extent, if any exists.
(c) If the Administrator determines in accordance with Chapter 12, Section 1(a)(i) that an alluvial valley floor exists within the proposed permit area and it occurs on proposed affected lands, a complete application shall include unless determined to be unnecessary: - (i) Maps which describe the extent of the alluvial valley floor, the undeveloped rangeland and areas of subirrigation and flood irrigation agricultural activities.
- (ii) Excepting areas of undeveloped rangeland, a comparison of the productivity of areas of subirrigation and flood irrigation agricultural activities to total farm productivity.
- (iii) Maps which describe and locate diversion structures, ditches, fencing patterns and other farm improvements occurring on the alluvial valley floor.
- (iv) Geologic data, including geologic structure, and geologic cross-sections pertinent to the alluvial valley floor.
- (v) Soils and vegetation data, including a detailed soil survey and chemical and physical analyses of soils, a vegetation map with descriptions of quantitative and qualitative surveys, land use data and crop yields pertinent to the alluvial valley floor.
- (vi) A description of the surface hydrology including streamflow, runoff, sediment yield, and water quality which shows seasonal variations, and geomorphic studies.
- (vii) Geohydrologic descriptions including, where applicable, potentiometric surfaces pertinent to the alluvial valley floor, groundwater quality and aquifer characteristics of those aquifers which support subirrigation or flood irrigation agricultural activities on the alluvial valley floor, a well and spring inventory, and physical and chemical analysis of overburden to determine the effect of the proposed mining and reclamation operations on groundwater quality and quantity that support alluvial valley floors.
- (viii) Information necessary to identify those geologic, hydrologic and biologic characteristics which support the essential hydrologic functions which might be affected by the mining and reclamation process. The information required by this subparagraph shall evaluate those factors which contribute to collecting, storing, regulating and making the natural flow of water available for agricultural activities on the alluvial valley floor, including, but not limited to:
- (A) Characteristics of the erosional state of the stream;
- (B) Characteristics and maps of the surface and groundwater balance;
- (C) Characteristics of the topography, soil and vegetation existing on the alluvial valley floor;
- (D) Factors contributing to the function of collecting water, such as amount, rate and frequency of rainfall and runoff, surface roughness, slope and vegetative cover, infiltration, and evapotranspiration, relief, slope and density of drainage channels;
- (E) Factors contributing to the function of storing water, such as permeability, infiltration, porosity, depth and direction of ground water flow, and water holding capacity;
- (F) Factors contributing to the function of regulating the flow of surface and ground water, such as the longitudinal profile and slope of the valley and channels, the sinuosity and cross-sections of the channels, interchange of water between streams and associated alluvial and bedrock aquifers, and rates and amount of water supplied by these aquifers; and
- (G) Factors contributing to water availability, such as the presence of flood plains and terraces suitable for agricultural activities.
- (ix) Measures to be followed to comply with the performance standards for mining on alluvial valley floors, in accordance with Chapter 5, Section 3.
- (x) Where mining will be conducted on an alluvial valley floor, a demonstration that the agricultural utility and the level of productivity of the alluvial valley floor will be reestablished.
- (xi) Such other information which the Administrator shall require to determine the importance of the alluvial valley floor to farming and to characterize the essential hydrologic functions.
(d) If the Administrator determines in writing that an alluvial valley floor exists within the proposed permit area but does not occur on proposed affected lands, or is located on adjacent areas and the alluvial valley floor has areas of subirrigation and flood irrigation agricultural activities which are not subject to the statutory exclusions of W.S. § 35-11-406(n)(v), the application shall include, unless determined to be unnecessary, information required in subsection (c)(i) and (iv) of this Section and: - (i) An analysis of the premining surface water and groundwater quality and quantity, supplying the alluvial valley floors including a description of the aquifers which supply water to the subirrigation and flood irrigation agricultural activities of the alluvial valley floors.
- (ii) An analysis of the anticipated changes to the premining surface water and groundwater conditions as a result of the mining operation demonstrating that the proposed operation shall not materially damage the quantity or quality of water in surface and groundwater systems that supply those alluvial valley floors outside the affected lands or on adjacent areas.
- (iii) Measures to be used to comply with the applicable performance standards for mining adjacent to an alluvial valley floor.
- (iv) Such other information that the Administrator may require to determine if material damage will occur to quantity and quality of waters that supply alluvial valley floors not subject to the statutory exclusions of W.S. § 35-11-406(n)(v).
(e) If the Administrator determines that an alluvial valley floor exists within the permit area or on adjacent areas where the alluvial valley floor contains areas of subirrigation or flood irrigation agricultural activities which may reasonably be expected to be affected, the application shall contain a monitoring plan to meet the requirements of Chapter 5, Section 3(b).
(f) Where the Administrator determines that an alluvial valley floor is important to farming on the basis of a comparison of the productivity of the affected alluvial valley floor (those portions of an alluvial valley floor where subirrigation or flood irrigation agricultural activities have historically or do presently exist and where continued farming on these areas would be interrupted, discontinued or precluded by the proposed mining operation) to a farm's total agricultural production, the permit application shall affirmatively demonstrate that the mining operation will not interrupt, discontinue or preclude farming on the alluvial valley floor. An area of affected alluvial valley floor shall be significant to a farm's agricultural production, when on the basis of a comparison of a farm's total agricultural production to the production of the affected alluvial valley floor the percentage loss exceeds ten percent or, if the farm's total production is less than 5,000 animal units or their equivalent, the product of the equation P = 3 + 0.0014 X, where "P" represents a negligible impact on farm production and "X" represents total farm agricultural production expressed as animal units or their equivalent in excess of 100.