AWWA WQTC64071

Water treatment is an important barrier against pathogenic microorganisms in drinking water.Since testing the produced water for the absence of indicators is insufficient to verify watersafety, Quantitative Microbiological Risk Assessment is now applied to better determinedrinking water safety. Data from twelve treatment systems was analyzed in this study todevelop methods to quantify pathogen reduction by a treatment system. Four approaches wereevaluated. Applying triangular distributions based on reported reduction in literature insteadof point estimates reduced uncertainty. Monitoring surrogates allowed a refinement of thistriangular distribution. Microbiological sampling provided the most accurate estimate ofnominal reduction, but could only be applied in the first stages of treatment. Modellingprocesses based on process conditions was most appropriate for disinfection processes.Simulations showed that the monitoring frequency can have a large impact on the outcome ofthe assessment. Thus, the presented QMRA methods provided input for verification ofcompliance to health based targets, risk identification, risk prioritization and designingmonitoring in the water safety plan. Includes 38 references, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2006

Number of Pages:

15

File Size:

1 file , 430 KB