Ways in which to conserve and reuse water are being developed to overcome limited fresh water supplies in the United States. This article discusses the approach of a facility, a wastewater treatment system that received a number of wastewater streams. Numerous technologies were assessed for microbial control including bleach, bromine, ozone, non-oxidizing biocides, peracetic acid and chlorine dioxide (ClO2) and after adjustments to the operation of the system, the use of CIO2 was effective. An investigation into the previous ineffective use of ClO2 and consequential changes to the system allowing ClO2 to be used as well as the results of ClO2 application are highlighted throughout the article.