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7. Identify Data Insufficiencies and Devise Plan to Fill Critical Data Gaps <br />CBM production in the Sand Wash Basin is in the early stages of development and ground-water <br />usage is concentrated in areas of private land ownership in the eastern part of the basin. <br />Accordingly, available aquifer data may be very limited in detail and geographic distribution. <br />These data are valuable for both evaluating and modeling possible depletive effects from CBM <br />development as well as establishing a bench mark against which future impacts can be <br />measured. Assessments of CBM development impacts in the Raton and San Juan Basins were <br />performed after considerable CBM development had already occurred. While this provided <br />geological data and historic production data from existing wells, there was a notable lack of <br />baseline data against which to compare to see if impacts to aquifers and streams were indeed <br />happening. In this emerging CBM basin it will be invaluable to identify data insufficiencies early <br />on so that critical baseline data collection can begin. This task will address types of data that <br />may be lacking to adequately characterize the basin as well as what type of baseline data should <br />be collected to evaluate possible impacts from CBM development and will identify priority areas <br />for gathering these additional data. Based on the identification of data insufficiencies in Task 7, a <br />plan will be developed to fill those priority gaps needed to complete the modeling. <br />8. Obtain New Field Data <br />This scope provides for collection of limited field data anticipated to be necessary for <br />characterizing the aquifer(s) and potentially impacted ground water as they pertain to CBM target <br />intervals and production water. Specifics about the data that will be collected will not be <br />ascertained until the study is well underway and will be guided by the results of previous tasks; <br />however, it is anticipated that data collection will focus on the eastern side of the basin in areas <br />where permitted water wells are most likely to be impacted by CBM development. The types of <br />data to be collected include, but are not limited to, the following: <br />1. Collect water level data from existing water wells; <br />2. Collect aquifer test data at existing water wells; <br />3. Water quality data (TDS, pH, Temperature, and major ions) from the following <br />sources: <br />• Existing water wells; <br />• Surface water bodies near contact areas with CBM target intervals. <br />Collecting these data will require access to existing wells that can be allowed to equilibrate for a <br />period of time prior to measuring water level depths and conducting aquifer tests. Modifications <br />may be necessary to the well pumps and pump controls so that aquifer tests can be performed. <br />Part of this task will be identification of wells that would be suitable for these tasks with assistance <br />from Moffat County. <br />9. Depletion Modeling <br />Apply the "Glover" methodology in one of its formats to determine the amounts of depletion from <br />surface water (alternate methods may be applied if the Glover method is unsuitable for the <br />hydrogeology of the basin). The Glover depletion analyses shall include a sufficient number of <br />runs to adequately characterize the current and estimated future levels of depletions to the <br />surface stream system, and to identify, as appropriate, any areas within the target formations that <br />could be considered to be nontributary. The analysis may also require sensitivity analyses of <br />various input values as part of the tests of guiding assumptions. The analyses and report will <br />identify and fully describe the following items: <br />1. Geometry and Setup; <br />2. The Aquifer Parameters Applied in Each Run; <br />3. Magnitude of Depletions -Current Levels of Production; <br />a. Depletions vs. Reduction in Accretion (Outflow); <br />5 <br />