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Page 2, April 24, 2013 <br />The value reported on this DMR for Outfall 010 was 0.4 ug/l, which was the highest of the two reliable <br />monthly PD Se ICP -MS values for this quarter (0.4 ug/l February and 0.3 ug/l March, (no flow January)). <br />PSCM believes the 55 and 41 ug/1 values noted above to be a false high values, based on the other three <br />Se analyses performed on each sample. As one would expect the total recoverable method to result in the <br />same, or higher, value than the potentially dissolved method (the former involves a hot acid digestion, <br />while the later involves a cold acid digestion), we suspect that the 55 and 41 ug/1 values to be in error. <br />This may be due to matrix interference in the sample that displays itself in the potentially dissolved ICP - <br />MS method. An additional TR digestion apparently removes that interference. The AA- Hydride method <br />does not have the same matrix interference problem that the PD ICP -MS method does. <br />Furthermore, the DMR certification statement says: <br />"I certify under penalty of law that this document and all attachments were prepared under my <br />direction or supervision in accordance with a system designed to assure that qualified personnel property <br />gather and evaluate the information submitted. Based on my inquiry of the person or persons who <br />manage the system, or those persons directly responsible for gathering the information, the information <br />submitted is to the best of my knowledge and belief, true, accurate and complete. I am aware that there <br />are significant penalties for submitting false information, including the possibility of fine and <br />imprisonment for knowing violations." <br />Since PSCM feels that the 55 and 41 ug/L Se values are NOT accurate, we feel obligated not to use those <br />values on the DMRs. <br />The lab reports for these samples are attached to this cover letter. They are (in order); the report indicating <br />the February 55 ug/L Se (PD by ICP -MS) and the 0.4 ug/L Se (TR by ICP -MS), the report indicating the <br />February 0.4 ug/L Se (PD by ICP -MS, with additional digestion), the February report indicating < 1 ug/L <br />Se (by AA- Hydride, the `U' qualifier on the lab report indicates that the value was less than the MDL, 1 <br />ug/L), and the March report indicating all four Se values (the `redigested' PD ICP -MS Se value is <br />reported as "Selenium, total potentially dissolved "). <br />No excursions of effluent limits occurred this quarter. Please contact me at 970 - 276 -5209 if you have any <br />questions. <br />Sincerely, <br />Dennis Jones <br />Hydrologist I <br />cc: Mr. Jared Ebert <br />Division of Reclamation, Mining and Safety <br />1313 Sherman Street, Room 215 <br />Denver, CO 80203 -2273 <br />