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2 <br />Colorado Division of Reclamation and Mine Safety (CDRMS) defined Numeric <br />Protective Levels (NPL) and Early Warning Indicators (EWI) are shown for each <br />constituent at each well where these statistical values apply. <br />Comparison of the data values with the Early Warning Indicators (EWI) and the <br />Numeric Protective Levels (NPL) indicates one data point for dissolved sodium <br />elevated above the EWI at down gradient alluvial well 21 -5 during the quarter. <br />The sample, collected in March 2014, was reported with a value for dissolved <br />sodium of 519 mg /L. The calculated EWI for this constituent at this monitoring <br />point is 498 mg /L, a difference of 21 mg /L. The baseline mean value for dissolved <br />sodium for this well is 443 mg /L computed from 15 baseline samples. The <br />maximum value for dissolved sodium observed in the baseline program was 456 <br />mg /L. The operational mean value determined from 89 samples is 473 mg /L. <br />The value of dissolved sodium at alluvial well 21 -5 has exceeded the calculated <br />EWI twelve times previously in the operational period of record. These points are <br />summarized in the following table along with their respective sample dates: <br />Sample Date <br />Alluvial Well 21 -5 <br />Dissolved Sodium (mg /L) <br />Early Warning Indicator <br />498 <br />April 2, 2002 <br />505 <br />January 19, 2004 <br />500 <br />June 21, 2004 <br />518 <br />September 10, 2004 <br />520 <br />June 13, 2008 <br />505 <br />June 11, 2008 <br />517 <br />September 16, 2010 <br />499 <br />June 7, 2012 <br />518 <br />September 9, 2012 <br />506 <br />November 18, 2012 <br />529 <br />March 11, 2013 <br />524 <br />