Laserfiche WebLink
involves a cold acid digestion). Therefore, we suspect that the 6.5 ug /1 value is in error. <br />This may be due to matrix interference in the sample that displays itself in the potentially <br />dissolved ICP -MS method. The previously submitted DMR for Outfall 004 indicated the <br />6.5 ug /1 value as the highest 30 day average and daily maximum. Therefore, that DMR <br />has not been revised. <br />For the second quarter of 2012 at Outfalls 002 and 004, all potentially dissolved selenium <br />values reported on the DMRs were values obtained by ICP -MS, EPA Method M200.8. <br />Therefore, the associated DMRs have not been revised. The Outfall 002 potentially <br />dissolved selenium value was 4.7 ug /1 on a sample collected June 6. This value was <br />obtained by ICP -MS, EPA Method M200.8. However, one other selenium test method <br />was performed on this sample, because we are investigating the differences in the <br />methods. The total recoverable selenium value was 3.4 ug /1 on the same sample. This <br />value was obtained by ICP -MS, EPA Method M200.8. The Outfall 004 potentially <br />dissolved selenium value was 5.7 ug /1 on a sample collected June 11. This value was <br />obtained by ICP -MS, EPA Method M200.8. One other selenium test method was <br />performed on this sample also. The total recoverable selenium value was 1.3 ug /1 on the <br />same sample; this value was obtained by ICP -MS, EPA Method M200.8. Since one <br />would expect the total recoverable method to result in the same, or higher, value than the <br />potentially dissolved method (the former involves a hot acid digestion, while the later <br />involves a cold acid digestion), we suspect that the 4.7 and 5.7 ug /1 values are in error. <br />This may be due to matrix interference in the sample that displays itself in the potentially <br />dissolved ICP -MS method. We have noticed this phenomenon in previous DMRs. <br />In accordance with the NOV /CDO, Peabody hereby certifies that Peabody will analyze <br />the effluent from the Facility using a method specified in 40 CFR Part 136 that is <br />capable of measuring to the lowest detection limit, at or below the current established <br />PQL of 1 ug /1 for potentially dissolved selenium. <br />Peabody is evaluating the lab procedures and potential testing interferences related to <br />selenium testing, and reserves the right to update or revise all DMRs when such <br />investigation and evaluation are complete. <br />Please call me at 970 - 276 -5209, or email me at djones @peabodyenergy.com, if you have <br />any questions. <br />2 <br />Sincerely, <br />Dennis Jones <br />Hydrologist I <br />Peabody Energy <br />P.O. Box 670 <br />37796 RCR 53 <br />Hayden, CO 81639 <br />