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<br /> 2) If CKD in area A2 was an ongoing source for barium and TDS loading to the groundwater, higher '
<br /> concentrations of barium would be expected in the Group 2 wells that are closer to CKD disposal area A2,
<br /> however the data indicates the opposite. The highest barium and TDS concentrations are in groundwater
<br /> samples from the Group 3 wells (MW-4, MW-6 and MW-7), which are located greater than 500 feet from '
<br /> CKD disposal area A2. Group 2 wells (MW-2 and MW-3)are located less than 100 feet from the CKD
<br /> disposal area and have lower concentrations of barium and TDS.
<br /> 3) Dissolved metals concentrations elevated above benchmark levels are only consistently observed for ,
<br /> barium. Elevated or upward trending concentrations of other constituents would be expected if CKD was
<br /> influencing groundwater concentrations in the Site wells. '
<br /> 4) Based on leaching tests of CKD solids and groundwater from other CKD-impacted sites, elevated pH values
<br /> and concentrations of potassium (and other constituents)would be expected for CKD impacted groundwater.
<br /> Groundwater pH values at the Site are between 7 and 9, which are similar to values observed in the wells '
<br /> prior to CKD placement in area A2, and do not show an increase in pH values or constituent concentrations
<br /> over time that would be expected if the waters were being influenced by CKD Ieachate. Potassium was not
<br /> measured prior to CKD placement; however, current concentrations are < 25 mg/L and show no increasing '
<br /> trends.
<br /> 9.0 REFERENCES '
<br /> Arthur, Michael A., Walter E. Dean, Richard M. Pollastro, George E. Claypool, and Peter A. Scholle 1985.
<br /> Comparative geochemical and mineralogical studies of two cyclic transgressive pelagic limestone units, '
<br /> Cretaceous Western Interior Basin, U.S., in Fine-Grained Deposits and Biofacies of the Cretaceous Western
<br /> Interior Seaway: Evidence of Cyclic Sedimentary Processes (FG 4). Tulsa, OK: The Society of Economic
<br /> Paleontologists and Mineralogists (SEPM), p. 16-27. '
<br /> Clark, LD and P. Fritz, 1997. Environmental Isotopes in Hydrogeology. Lewis Publishers, New York.
<br /> Cowie, R., Williams, M.W., Wireman, M., Runkel, R.L. 2014. Use of Natural and Applied Tracers to Guide '
<br /> Targeted Remediation Efforts in an Acid Mine Drainage System, Colorado Rockies, USA. Water 2014, 6, 745-
<br /> 777; doi:10.3390/w6040745.
<br /> Dean, W.E. and Arthur, M.A. 1998. Geochemical expressions of cyclicity in cretaceous pelagic limestone '
<br /> sequences: Niobrara Formation, Western Interior Seaway, in Stratigraphy and Paleoenvironments of the
<br /> Cretaceous Western Interior Seaway, USA: SEPM Concepts in Sedimentology and Paleontology No. 6. Tulsa, '
<br /> OK: The Society of Economic Paleontologists and Mineralogists (SEPM), p. 227-255.
<br /> DRMS, 1999. Technical Revision No. 3 (TR-003)to Permit No. M-77348; Colorado Division of Reclamation,
<br /> Mining and Safety, October 15, 1999. '
<br /> DRMS, 2012. File No. M-1977-348; Boettcher Limestone Quarry; Requirement for Additional Groundwater
<br /> Characterization/Sampling. Colorado Division of Reclamation, Mining and Safety, June 25, 2012.
<br /> Ideal, 1962. Report of Investigations, Boettcher Properties, Colorado. Ideal Exploration Department, Research
<br /> and Development Division, June 18, 1962. '
<br /> Ideal, 1977. Development Drilling, 1977, Boettcher, Colorado. Ideal Exploration and Properties Department,
<br /> August 12, 1977.
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