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Erica Crosby- CDMG ENV 234.04 <br />October 12, 2004 <br />Page 3 <br />There is a confirmed factor influencing the baseline data. Uinta supply well 20-8 was pumped to <br />supply water to the construction effort for the Commercial Mine process buildings. The effect of this <br />pumping was realized in the data once the pumping stopped. The termination of pumping of well 20-8 <br />also coincided with start-up of the solution mining well field and the end of the baseline time period. In <br />the first quarterly report covering October 1, 2000 through December 31, 2000, the pumping record of <br />well 20-8 is represented in the tables and graph regarding the water elevation summary for this well. <br />Pumping stopped right at the beginning of the fourth quarter 2000. Pumping of this well resulted in a <br />cone of depression that influenced the baseline data of several wells in the vicinity of well 20-8 to some <br />extent. The recovery of the cone of depression is represented in the water level graphs provided in <br />each of the subsequent quarterly reports. In several wells a very pronounced change in the water level <br />was noted as pumping of well 20-8 stopped. The wells influenced by the cone of depression showed <br />an increase in the water level at the beginning of the fourth quarter 2000. The water quality for many <br />of the wells also begins to change at this time period. Typically, water quality improves in the wells <br />once the pumping stops. This is the single biggest influencing factor in the baseline data and it helps <br />to explain many of the unusual patterns seen in the graphs. <br />2. Recommendation to continue monitoring all regulated parameters. <br />The majority of the constituents recommended to be dropped from the monitoring program have either <br />never been detected above the detection limit (5 years of monitoring) in the ground water wells and/or <br />the production stream or have been so infrequently observed from any monitoring site that they yield <br />little information. These constituents include dissolved aluminum, antimony, arsenic, beryllium, <br />cadmium, chromium, cobalt, copper, lead, manganese, mercury, molybdenum, nickel, selenium, silver, <br />thallium, uranium, vanadium, zinc, bromide, nitrate as N, nitrate/nitrite as N, and nitrite as N. Some of <br />these constituents have very short hold times requiring special sampling and handling of the samples <br />to insure that they get to the analytical laboratory from our remote location within the specified holding <br />time. There is an expense incurred in meeting these short hold times that does not seem to justify the <br />information that results from analysis of the samples as repeatedly below detection. No dependent <br />trends are identified from these constituents because they are so infrequently detected in the samples <br />above the detection limit. <br />In acknowledging the Division's concern that regulated constituents could possibly change and <br />concentrate over time such that they do present an unexpected environmental influence to the ground <br />water systems, American Soda proposes to monitor the regulated constituents on an annual basis <br />during commercial production operations. No additional monitoring of these regulated constituents <br />would be required during interim temporary suspension status unless it seems necessary to confirm <br />protection of the ground water as part of corrective action in the event the proposed TR-#4 parameters <br />show sustained elevated values. <br />3. Recommendation to continue monitoring major cations and anions. <br />American Soda agrees that data regarding all major cations and anions is valuable to evaluate <br />hydrochemical changes that could result from ground water mixing and to help confirm laboratory <br />analytical and reporting procedures. Included below is a list of the constituents that would need to be <br />retained for these purposes. American Soda will not establish levels or limits for these constituents <br />unless they are presently regulated but will sample and report them along with the parameters in <br />Appendix A. Relationships between these constituents will be periodically examined for changes that <br />could represent mixing. These additional constituents will include: <br />Calcium Magnesium Iron Chloride Sulfate <br />