AWWA JAW18195

This study reports on the occurrence of enteric viruses within a full-scale 205 mgd (776 ML/d) water treatment plant following each treatment process, including prechlorination-flocculation, sand filtration, and chlorination. Reduction of enteroviruses and rotaviruses averaged 81 and 93 percent, respectively, for the complete process. The highest removal of enteroviruses occurred during prechlorination-clarification and filtration, and the highest reduction in rotaviruses occurred after prechlorination-clarification and postchlorination of the finished water. Enteroviruses or rotaviruses could be isolated from 24 percent of the finished water samples containing >0.2 mg per liter levels of chlorine and meeting coliform bacteria (1 per 100 mL) and turbidity (1 ntu) standards. Although major plant deficiencies may have been responsible for the occurrence of viruses in the finished water, results of the study indicate that finished water, with measurable levels of free residual chlorine and meeting standards for coliform bacteria and turbidity, cannot be assumed to be virus free. Includes 30 references, tables, figure.

Product Details

Edition:

Vol. 78 - No. 1

Published:

01/01/1986

Number of Pages:

6

File Size:

1 file , 1.4 MB