AWWA WQTC62457

The U.S. Environmental Protection Agency (USEPA) recently conducted a validation study of Method 1103.1 (mTEC) for E. coli in wastewater effluent tocharacterize method performance across multiple laboratories and disinfected wastewater matrices and to developquantitative quality control (QC) acceptance criteria. Ten volunteer participant laboratories, a verificationlaboratory, and two research laboratories participated in the study. Each laboratory spiked samples with laboratory-preparedand BioBall™ E. coli (ATCC 11775) spikes. Method 1103.1 mean laboratory-specific recoveries of E.coli from disinfected wastewater samples spiked with laboratory-prepared and BioBall™ spikes had an overallmean recovery of 75.8% and 57.8%, respectively. Laboratory-specific relative standard deviations (RSDs) fromdisinfected wastewater samples spiked with laboratory-prepared spikes ranged from 3.7% to 114.6%, with anoverall pooled, within-laboratory RSD of 40.8%. Laboratory-specific relative standard deviations (RSDs) fromdisinfected wastewater samples spiked with BioBalls ranged from 0% to 34.6%, with an overall pooled, within-laboratoryRSD of 15.4%. Method 1103.1 laboratory-specific false positive confirmation rates for unspikeddisinfected/secondary results combined, ranged from 0% - 50%. Laboratory-specific false negative confirmationrates for unspiked disinfected/secondary results combined, ranged from 0% - 66.7%. Results from theinterlaboratory validation studies of Method 1103.1 and Method 1603 were used to compare method performancebased on recovery, precision, false positive and false negative confirmation rates. Method 1103.1 had significantlyhigher false positive and negative confirmation rates in comparison to Method 1603.

Product Details

Edition:

Vol. - No.

Published:

11/01/2005

Number of Pages:

4

File Size:

1 file , 150 KB