AWWA WQTC60570

The evaluation of the laboratory capacity for analyzing raw surface source water samples to detect Cryptosporidium oocysts and Giardia cysts by USEPA Method 1623, needs to consider the time needed for sample analysis and implementation of appropriate QA/QC. The estimated time involved with environmental sample analysis will be directly impacted by the physicochemical characteristics of the samples and the QA/QC procedures necessary to maintain compliance. The analyses in this report present a quantifiable estimate for each of the various parameters that are associated with sample analysis by USEPA Method 1623. To obtain reliable estimates of sample analysis parameters associated with Method 1623, the data analysis included 169 sample analyses that were classified as: Regular LT2 samples (110); matrix samples (29); Ongoing precision and recovery (OPR) (15); and, Method Blank (15). The period of this study included the months of July, August September and early October, 2003. The estimated parameters included in this analysis are: average time for sample elution; average time for immunomagnetic separation; average time for sample immunostaining; average time for sample examination (microscopy); concentrated pellet volume and number of subsamples analyzed (given as percents); percent of clogged filters; percent of samples with more than one filter; percent of rejected samples (out of temperature, out of holding times, sampled out of schedule); percent of re-scheduled samples; and, average sample analysis turn-around. The data were stratified by state of origin and sub-stratified by sampling date and number of sub-samples analyzed. All OPR and method blank samples yielded pellet volumes of < 0.5 mL eliminating the need to perform the analysis of subsamples. Includes tables, figures.