Laserfiche WebLink
<br />Anomalously high Cd values were reported in samples collected by <br />Halepaska October 26-27. Station RS-5 reported 0.047 mg/1 Total Cd <br />and <0.005 mg/1 Dissolved Cd. Station M-9 reported 0.010 dissolved <br />Cd; Total Cd was not measured. <br />Anomalously high Cd values were reported in samples collected by <br />Halepaska November 11. Station RS-5 reported 0.085 mg/1 dissolved <br />Cd and <0.005 mg/1 total Cd. A re-analysis report from Core Labs <br />indicates that the values were confirmed. <br />An anamolously high Cd value was reported in a sample collected by <br />Halepaska November 23. Station M-9 reported 0.005 mg/1 dissolved <br />Cd. A re-analysis is in progress. A sample of RS-4 taken by Ann <br />Maest (RCG Hagler/Bailly - 3rd party sampler), anc3 which is <br />mistakenly called RS-4, failed to confirm the high value. <br />Thus, the field stations that have reported high values include <br />RS-1 <br />RS-2 <br />RS-5 (2 times) <br />M-4 <br />M-4 duplicate <br />M-9 (3 times) <br />D-87-24 <br />11/14/92 Rinse Blank <br />DISCUSSION <br />The detection limit of Cd according to the ICP method is 0.005 <br />mg/1. This value has been exceeded in each of the above cases. <br />The Colorado Basic Stream Standard for Class 1 Aquatic life at <br />lowest alkalinity is 0.0004 mg/1 (see Table III, Basic: Standards <br />and Methodologies, 3.1.0 (5CCR 1002-8) Colorado Department of <br />Health, 1984). This value has been exceeded in all cases. <br />The detection limit for Cd using the ICP is too low to cdetect what <br />could be determined to be safe levels for aquatic life. <br />The occurrence of Cd in the Rinse Blank sample indicates field <br />contamination more than anything else. However, the occurrence of <br />Cd in well M-9 on three separate occasions and in R:5-5 on two <br />separate occasions is suspicious. <br />The Quarterly Monitoring Report, which Halapeska submitted January <br />13, indicates that the high Cd values may be the result of cadmium <br />nitrate contamination in the field. (Cadmium nitrate is used to <br />precipitate dissolved sulfides.) However, this supposition is <br />inconclusive and is not backed by any independant analyses. <br />2 <br />