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Several water systems throughout the United States failed tocomply with the Stage 1 Disinfectants/Disinfection Byproduct Rule (D/DBPRule) this past year. With the Stage 2 D/DBP Rule scheduled to bepromulgated by the end of this year (2005), even more utilities will be out ofcompliance with DBP regulations in the future unless significant operationalor treatment changes are implemented. Conversion to chloramines hasbeen the fall-back for many utilities. However, chloramines are notnecessarily the answer for all utilities, especially those concerned aboutsecurity issues, wastewater nitrogen levels, increased distribution systemoperations, health affects associated with nitrogenous DBPs, or sitingammonia storage and feed facilities. The purpose of this paper is to brieflydiscuss DBP control options and present results from a case study thatbought DBPs under control without switching to chloramines. The controloptions examined include:lowering applied chlorine dose;altering pH in the distribution system;implementing operational changes to decrease detention time in thedistribution system;using chlorine dioxide as a pre-oxidant; and,converting to chloramines.The study demonstrated that THM and HAA levels can be reduced tovarying degrees (10 to 40%) depending on the control option employed andthe characteristics of the source water. Interestingly, all options reducedTHM and HAA levels to different extents. For example, chlorine dioxidereduced THM levels by as much as 40%, but usually had very little effect onHAA levels, whereas lowering the applied chlorine dose had a greater effecton HAA levels. Includes tables, figures.

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Edition: Vol. - No. Published: 11/01/2005 Number of Pages: 20File Size: 1 file , 760 KB