AWWA JAW34271

Disinfection byproducts (DBPs) in water treatment facilities in Utah were studied to determine their occurrence and to evaluate the correlation between levels of trihalomethanes (THMs) and other DBPs. Water samples from 14 medium and large treatment plants and 21 small plants were analyzed for DBPs at three times: as instantaneous formation, at the longest retention time in the distribution system, and as seven-day formation potential. THMs in plant effluents accounted for 64 percent (weight basis) of all DBPs measured, whereas haloacetic acids accounted for 30 percent, haloacetonitriles 3 percent, haloketones 2 percent, and 2,4,6-trichlorophenol and chloropicrin traces. The formation of all measured DBPs except trichlorophenol increased with the simulated distribution holding time. Chlorate was found (at~50 ug/L) in finished waters that had been disinfected with liquid chlorine. Includes 15 references, tables, figures.