Disinfection for potable reuse

The goal of the reuse demonstration plant discussed in the paper is to produce a water of equal or better quality than the excellent existing potable water supply for Denver. One measure of water quality is the presence or absence of pathogenic organisms. This goal can be achieved using bacterial indicators and coliphage, even during the extreme variability of start-up conditions. The production of a water of lower bacterial count than potable water produced from first-use mountain runoff has been demonstrated by using the multiple pathogen barriers of lime treatment, ozone, reverse osmosis, and chlorine dioxide disinfection. Although meeting existing drinking water standards does not ensure potability, the performance thus far indicates that a large safety factor exists for public health protection.