The Water Science and Technology Board has released the first report of the Committee on Public
Water Supply Distribution Systems: Assessing and Reducing Risks, which is studying water quality issues
associated with public water supply distribution systems and their potential risks to consumers. The distribution
system, which is a critical component of every drinking water utility, constitutes a significant management
challenge from both an operational and public health standpoint. This first report was requested by the EPA, as
the agency considers revisions to the Total Coliform Rule with potential new requirements for ensuring the
integrity of the distribution system. This first report identifies trends relevant to the deterioration of drinking water
quality in distribution systems and prioritizes issues of greatest concern according to high, medium, and
low priority categories. Of the issues presented in nine EPA white papers that were reviewed by the committee,
cross connections and backflow, new or repaired water mains, and finished water storage facilities were judged
by the committee to be of the highest importance based on their associated potential health risks. In addition,
the report noted that two other issues should also be accorded high priority: premise plumbing and distribution
system operator training. This first report will be followed in about 18 months by a more comprehensive final
report that evaluates approaches for risk characterization and identifies strategies that could be considered to
reduce the risks posed by water-quality deteriorating events.Table of Contents


FrontMatter
1 Introduction
2 Trends Relevant to the Deterioration of Drinking Water in Distribution Systems
3 Highest Priority Issues
4 Medium Priority Issues
5 Lower Priority Issues
6 Summary
References
Appendix A Committee Biographical Information