AWWA WQTC65880

In an attempt to reduce health risk from bathing waters, microbiological standards for E.coli and intestinal enterococci were implemented in European legislation. Furthermore, waterquality management is required with respect to sources and spreading of fecal pollution. One ofthe tools in this process is predictive modeling which requires quantitative data on the decay rateof both indicator bacteria. The decay rate index (DRI) at different water temperatures for E. coliand enterococci in freshwater was determined based on batch experiments with environmentaland pre-cultured indicators. Results showed thatenterococci were similar or less persistent than E. coli in freshwater. In salt water, however,enterococci are more persistent. Decay increased with temperature, and for E. coli andenterococci the Arrhenius constant was estimated at 1.05 and 1.06, respectively. The highvariability of the calculated DRI-values implicates high uncertainty of the concentrations derivedfrom predictive modeling. More research is needed to elucidate the microbial and environmentalfactors influencing the decay rate of both indicators which enables the use of more precise andspecific DRI-values for local situations. Includes 2 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2007

Number of Pages:

8

File Size:

1 file , 280 KB