AWWA JAW63326

The two-stage Disinfectants/Disinfection Byproducts Rule promulgated by the US Environmental Protection Agency (USEPA) requires "enhanced coagulation," which attempts to control the formation of disinfection byproducts (DBPs) through the removal of total organic carbon (TOC). Utilities must achieve TOC removals as prescribed by the USEPA's enhanced coagulation matrix. This research proposes an alternative matrix based on specific ultraviolet absorbance (SUVA) rather than TOC. The authors analyzed data collected under the Information Collection Rule and found a clear relationship between SUVA, source water characteristics, and the effectiveness of coagulation for the removal of TOC and UV-absorbing substances. Research findings showed the ability of SUVA to predict the reactivity and removal of natural organic matter (NOM). In this article the authors propose that enhanced coagulation requirements based on SUVA would facilitate compliance with maximum contaminant levels and help utilities optimize coagulant dosing and NOM removal as well as control the generation of DBPs. Includes 28 references, tables, figures.