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2. Characterize Basin Stratigraphy and Structure <br />The geology will be adequately characterized to facilitate the depletion analyses for as many <br />wells as will be required to sufficiently determine the overall levels of depletion in rate and annual <br />volume and the location or locations of nontributary areas within the basin. As a minimum the <br />following items will be addressed and summarized in the report: <br />1. Basin Stratigraphy <br />2. Target Producing Formations <br />3. Formation Gas Pressures and Areas of Gas Discharge <br />It is recognized that the existence of higher gas pressure in the formations and gas <br />discharge from the formation water can have an impact on the ability of water to infiltrate <br />into the formation in any such areas. Accordingly, the study will require identification of <br />any such areas and an assessment of the potential for elevated gas pressures or gas <br />discharge to reduce or eliminate stream depletion where it otherwise might be occurring, <br />based on all other factors. <br />4. Basin Geologic Structure <br />5. Formation Outcrop Areas and Configuration <br />6. Spatial Variation in Lithologies or Characteristics Bearing on CBM Production <br />3. Characterize Regional Ground-water Flow Systems; <br />The hydrogeologic characteristics pertinent to the depletion analyses will be thoroughly assessed <br />for each differing hydrologic regime so that reliable depletion analyses can be carried out within <br />the basin. With respect to the aquifer characteristics noted below, it is required that, --assuming a <br />range of values is developed -- the values utilized in the actual depletion analyses runs, and <br />ultimately applied, will be assessed for reasonableness and appropriateness. In addition, there <br />will be required sensitivity analyses on each characteristic used in the analyses so that the level <br />of potential variation in the results can be understood. The work under this category will include <br />assessments, at a minimum, of the following items: <br />1. Identification of Regional Ground Water Flow Systems: <br />o Characterize Regional Ground Water Flow Systems; <br />o Identify Target Intervals to be De-watered in Relation to Regional Ground Water Flow <br />Systems; <br />o Identify Potential Flow Pathways Between Target Intervals and Aquifers or Tributary <br />Surface Water Systems; <br />~o Rank Potential Flow Pathways according to Potential to Impact to Tributary Water Within <br />Regulatory Time Constraints. <br />2. Aquifer (or identified pathway) Characteristics: <br />o Hydraulic Conductivities; <br />o Saturated Thicknesses; <br />o Porosities and Specific Yield Values. <br />3. Aquifer Extent and Boundary Conditions: <br />o Lateral and Spatial Extent; <br />o Nature of the Boundary, e.g., Outcropping at Surface or Fault Truncated, Etc.; <br />o Discharge Areas (springs or streams gaining via formation contact); <br />o Recharge Areas. <br />4. Water-Level Conditions <br />o Confined/unconfined; <br />o Pre-CBM flow conditions; <br />o Surface Discharge: <br />^ Location; <br />^ Amount; <br />^ Rate; <br />^ Annual Volume. <br />3 <br />