A DBP Control Method Using Localized Treatment and Distribution System Modeling

Abstract

The Las Vegas Valley Water District (LVVWD) has experienced rapid expansion of its water distribution system for many years, and has observed water age related issues in the early stages of new development, where large scale water facilities have been constructed and few homes occupied. The increased water age not only results in low chlorine residual, it also contributes to DBP formation. The LVVWD has also observed that water age in development areas reduces over time as more homes are occupied and water demand increases. To address this issue, the LVVWD is investigating localized treatment technologies and is participating in an American Water Works Association Research Foundation Tailored Collaboration Project 3103, entitled “Localized Treatment for Disinfection By-products” (AWWARF Project). The LVVWD has also studied operating strategies to reduce water age in its distribution system. This paper describes a conceptual plan to use a combination of localized treatment and operating strategies as an alternative to using chloramination. Topics discussed include research status of localized treatment options and the feasibility of combining localized treatment with distribution system modeling. Future options are also discussed for treatment plant relocation, from areas where water age issues have resolved themselves, to new development areas.