2012-06-20_PERMIT FILE - C2010089 (87)

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entities to concurrently determine the role and long -term value of alluvial valley floors. Only in this manner could the impact of mining be completely evaluated. TABLE 4 PROPOSED' REQUIREMENTS FOR INFORMATION FOR COAL MINING - PLANS INVOLVING ALLUVIAL VALLEY FLOORS (SURFACE OPERATIONS) I. Geologic Information IA. Regional Geologic Map of scale 1:250,000 showing formatio m era, location of type sections and sources of information a thin 25 kilometers of mine tract having ephemeral and e and 80 kilometers of perennial streams (where the str -, on the "area of operations" as defined'in 30 CFR 211.2, ral Regula- tions). IR. Regional structure Map of scale of 1:250,000 showing major fracture and fault systems in area covered by Regional Geologic Map (IA.), with measured atti- tudes (dip and strike) of major formations and the major geologic struc- tures (may be included on Regional Geologic Map). IC. Area of Operations Geologic, Topographic, and Structure Map of scale • 1:24,000 (contour interval where required 3.3 meters or less) showing all strata of contrasting lithologies, attitudes, fracture patterns and faults located within the area of operations and /or with reference to type sec- tions located outside the area. Map to be prepared from base data having a horizontal accuracy of + 5 meters when denoting significant changes in bedrock lithology or structure. ID. Affected Area Geologic and Structure Cross Sections of scale (vertical and horizontal 1:24,000 for affected area and 1:4800 for the area of opera- • tions showing all strata of contrasting lithologies and their attitude when such strata are located between the surface and within 70 meters be- low the deepest coal seam to be mined by surface methods or to a depth of 200 meters of the premining ground surface (within the area of operations) whichever most adequately represents the affected hydrologic system. Show locations of all points of detailed measurements. Locate cross sections on appropriate Geologic Maps. Provide at least two cross sections, one perpendicular to the general strike of strata within the affected area, one parallel to the strike, and any other cross sections deemed necessary to show departures from these sections (departures in terms of structure and lithology) where the departures - affect the hydrology, overburden toxi- city, or mining procedures. (Note: "Affected Area" defined in 30 CFR 211.2). IE. Detailed Lithologic Logs of Cored Drill Roles located on transects across the eubirrigated alluvial valley floor area(s) where such areas are lo- cated within the area of operations. Logs to show changes in lithology from the premining ground surface to a depth which includes 70 meters of the strata lying beneath the deepest coal seam proposed to be extracted. (i.ithology based upon visual observations and any appropriate geophysical logs.) Provide at_a scale of 1:200 in the vertical. These core holes will transect the alluvial valley floors and any related deposits as designated by the regulatory authority in sufficient number to provide the location to stratigraphic (lithologic) markers across the entire cross section (IF.) to within 2 meters and to show changes in strata that may • affect the hydrology, overburden toxicity or mining procedures. (See also "Detailed Cross Sections of Alluvial Valley Floor Areas" (IF.) and requirements for hydrology data (III)). IF. Detailed Cross Sections of Alluvial Valley Floor areas based upon the "Detailed Lithologic Logs of Cored Drill Roles" which show significant changes in subsurface lithology under the areas designated by the regula- tory authority as alluvial valley floor areas (includes hydrologically - 1) "Regulatory Authority" refers to the public body with responsibility to review and approve mining plans for surface coal mints.