ABSTRACT
Drinking water is not sterile. Public water supply has never been intended to provide a sterile product. The objective has always been to produce a water supply of minimal public health risk with secondary considerations being given to taste and odor. Specialized uses of public water supply need to recognize their obligation to further treat the water at their site if desired quality requires enhancement beyond consumer health protection. The microbial quality of potable water is a reflection of those organisms introduced in source water, modified in composition through treatment processes, colonized in the distribution system, and selectively amplified in various attachment devices. Rivers are subject to big fluctuations in water quality as a result of storm-water runoff and spills of municipal and industrial wastes. While these source waters are not necessarily of the best quality, there is assurance that quantity will be available to meet the needs of the growing community.
