AWWA JAW62659

This article organizes disinfection history since the 1881 founding of AWWA into a construct of eight disinfection "revolutions", events or series of events that changed the practice of disinfection in the United States. The revolutions include: in 1908 Jersey City, New Jersey, began full-scale disinfection by adding hypochlorite of lime to water in the Boonton reservoir that supplied Jersey City; in 1914 the coliform revolution combined a numerical standard with an analytical technique that could be applied widely and relatively inexpensively to regulate an indicator organism that measured the sanitary quality and, ultimately, the microbiological safety of drinking water; in 1917 the implementation of the practice of combining ammonia and chlorine to produce chloramines to solve taste and odor problems related to free chlorine; in 1974 the discovery of trihalomethanes (THMs) and the resulting THM regulation in 1979 began the first revolution in drinking water disinfection practices; the requirement of the Surface Water Treatment Rule (SWTR) in 1989 of specific contact time (CT) values to be achieved during treatment of surface waters on a daily basis; in 1989 the Total Coliform Rule (TCR) required utilities to comply with no more than a 5% positive coliform occurrence in samples, a shift in requirement from coliform density to presence-absence of coliforms; in 1998 a new approach to regulating risks of disease from disinfection byproducts (DBPs) was promulgated in the Stage 1 Disinfectant/Disinfection Byproduct Rule (D/DBPR) and later in the Stage 2 D/DBPR; and, in 1993 the Milwaukee, Wisconsin outbreak of cryptosporidiosis sparked a revolution in Cryptosporidium detection methods resulting in the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR). The article goes on to discuss how the revolutions transformed U.S. disinfection practices and gives a case study of how the Metropolitan Water District of Southern California switched from free chlorine to chloramines. Includes 66 references, table, figures.