AWWA WQTC71610

The U.S. Environmental Protection Agency's (USEPA's) Long Term 2Enhanced Surface Water Treatment Rule (LT2) requires all water systemsoperating under filtration avoidance status to add a second disinfectant to theirtreatment system or to add filtration. As stated in the LT2 rule, the most economicalsolution for unfiltered systems to meet the requirements of LT2 is typically ultraviolet(UV) disinfection.Each unfiltered water utility must understand and address all issues that could affect thebest method of disinfection before selecting their treatment approach. UV disinfectionmay not be the best choice in all cases. Systems that have periodic high turbidity events,taste and odor issues, disinfection byproduct (DBP) compliance issues, iron andmanganese concerns or the potential for significant changes to their source water supplyneed to consider other disinfectants to determine the best second disinfectant for theirparticular water system. Other alternatives may allow these systems to deal with theirspecific challenges and bring their system into compliance with LT2 at the same timeand remain an unfiltered water system. In this context, this study discusses three (Ketchikan Public Utilities, the City of Kodiak, and the City and Borough of Sitka) of Alaska's unfiltered water systems thathave water quality challenges that necessitated careful review of the availabledisinfection alternatives before disinfectant selection was completed. Includes figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

6

File Size:

1 file , 1 MB