AWWA JAW17240

Point-of-use water treatment devices were investigated to identify organisms that may colonize these filters, to determine the magnitude of the postcolonization release of microorganisms into the product water during daily use or after periods of nonuse, and to demonstrate the effect of tap water of marginal bacteriological quality on the quality of the product water. The bacterial count was found to vary between units of the same design, and between water samples from the same filter unit collected at different times of the day; it was affected by the length of time the filter cartridge had been in use, the design of the cartridge, and the temperature of the water, as well as by the species of microorganism. The filters chosen for this three-year laboratory investigation were those designed to be connected to the cold water line under the kitchen sink and plumbed to a common mixing faucet. A discussion of the health effects associated with the use of these devices and of point-of-use water treatment unit design considerations is included in this article. Includes 26 references, tables, figures.