AWWA QTC97002

Distribution systems are vulnerable to low level endemic contamination or severe accidental contamination that can occur as a result of line failures, repairs and cross connections. Several studies have shown that E. coli can be detected in drinking water distribution systems and that its presence cannot always be explained by obvious errors in the treatment process, broken water mains or accidental contamination. Low levels of coliforms have demonstrated the ability to grow in distribution networks. However, apart from results confirming that enteric bacteria can grow in rather dilute and cold environments (compared to the digestive tract), little or nothing is known about the behavior of bacteria accidentally entering distribution systems under these conditions. This study used two post-chlorinated drinking water distribution systems to obtain some preliminary answers to this question. The systems were contaminated by a single injection of 10 liters of wastewater containing fecal microorganisms, dissolved organic matter and other particulates. The first distribution system was fed with post-chlorinated biologically treated water containing microorganisms and nutrients. The second was fed with post-chlorinated nanofiltered water containing very low concentrations of microorganisms and biodegradable organic matter. The study was designed to determine the impact of accidental contamination in a dilute environment and to assess the vulnerability of these two drinking water distribution systems.

Product Details

Published:

01/01/1997

ISBN(s):

0898679583

Number of Pages:

14

File Size:

1 file , 270 KB