AWWA ACE69002

This powerpoint presentation begins by presenting a brief overview of radionuclides and how they are formed. The Colorado Radionuclide Abatement and Disposal Strategy is presented, along with the Radionuclide Sample Variability Investigation. The project approach included aliterature review, laboratory standard operating procedures (SOPs) Review and Survey, and a confirmation sampling program. Lessons learned from sampling include the following:lab selection could impact compliance;same sample analyzed by various laboratories produced awide variety of results for GAA and radium;variability could be attributed to a wide variety of issues; for example, sample volumes analyzed, samplepreparation methods, calibration standard selection, andcount times; conversion of uranium from mass to activity can havesignificant compliance implications; for example, using the conservative 0.67 pCi/ug mass toactivity ratio can result in non-compliance with adjusted GAA. Big picture recommendations include the following:use U.S. Environmental Protection Agency's (USEPA's) GAA Method 900.0 for screening purposes;for example, if GAA > ~5 and <~30 pCi/L: require system to conductadditional sampling using USEPA Method 00-02 (co-precipitation),which is believed by some industry experts to be more accurate andprecise;further evaluate GAA variability using EPA Method 00-02;further investigate radium variability;for systems that have potential adjusted GAA compliance issuesand confirmed uranium present: identify source-specific mass-to-activityratio;measure U-238 to U-234 isotopically and determine conversion ormeasure uranium activity directly. Impacts to Colorado Department of Public Health and Environment (CDPHE):direct benefits to CO-RADS;consistent sampling and analysis protocols were used to ensure betterquality data;understanding variability provided insight during data evaluation;indirect benefits to Laboratory Certification Program;greater awareness of issue and potential magnitude;increased scrutiny of certified labs; and,issues will need additional investigation before long termimprovements will be made. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2008

Number of Pages:

30

File Size:

1 file , 1.3 MB