AWWA WQTC57146

This paper outlines 10 logical steps to be followed in making the decision on whether to switch from free chlorine to chloramines for final disinfection. Based on findings to date, it is apparent that chloramine treatment should not be just an "add on" treatment process for final disinfection. Final disinfection with chloramines should be an integral part of both the water treatment process, and the design, operation and maintenance of the distribution system. This is perhaps the most significant issue that has come to light since the original THM Rule, (which stipulated a level of 100 ug/L for a running annual average (RAA) in the distribution system) became effective causing numerous utilities to add ammonia to form chloramines. To emphasize this issue, we are suggesting that the disinfection process terminology be changed from the traditional "secondary disinfection" to "final disinfection". Thus, to support a more integrated, comprehensive approach in selecting a final disinfectant, the following steps have been developed: review the existing situation and identify major issues;establish system goals and specific objectives; develop and screen alternative approaches; optimize source, treatment, and distribution system facilities AND/OR optimize final disinfection strategy; refine and confirm specific final disinfection objectives; establish evaluation criteria and develop rating system;gather additional information and evaluate stakeholder's preferences; apply evaluation criteria and rate and rank strategies; decide whether to switch to chloramines; and, develop implementation plan. Includes 9 references, figure.

Product Details

Edition:

Vol. - No.

Published:

11/01/2002

Number of Pages:

11

File Size:

1 file , 330 KB