AWWA WQTC50451

When the ICR DBP Methods Manual was developed in 1994, there was a concern that setting measurement quality objectives (MQOs) too tight might lead to a problem with inadequate lab capacity for the required monitoring. This decision was based on an evaluation of the existing PE study data, which demonstrated that nationwide performance on certain key ICR parameters was quite variable or there was concern that the methods might not be sufficiently rugged at the levels of interest. Data from at least a single lab for the ICR demonstrates that this assumption was fallacious, and extremely precise (and presumably accurate) data are available for critical parameters. Preliminary evaluation of multi-lab data leads to similar conclusions. In spite of the existence of nationwide data demonstrating the feasibility of excellent precision. particularly for the haloacetic acids, the now privatized Water Supply performance evaluation studies are still using inappropriate acceptance criteria. Allowing less than ideal data to be used for decision making. Includes reference, tables, figures.