AWWA WQTC52957

The performance of EPA Methods 1622 and 1623 during the InformationCollection Rule Supplemental Surveys (ICRSS) was anticipated to be comparable to the methods' performance during the interlaboratory validation studies conducted prior to the surveys. In addition to the quantitative performance of the methods demonstrated during the validation studies, the methods were expected to provide more reliable protozoa occurrence data than the ICR protozoa method. Data from the ICRSS confirm that the methods met both of these expectations. Includes 9 references, tables, figures.