1. US Environmental and Protection Agency Office of Water The Clean Water and Drinking Water Infrastructure Gap Analysis Report EPA-816-R-02-020 pp. 9-15 31-35. September 2002.
2. American Water Works Association Infrastructure Needs for the Public Water Supply Sector Denver Colorado December 2001.
3. American Water Works Association www.awwa.org/advocacy/learn/425factsaboutwater.cfm
4. American Water Works Association Water Audits and Leak Detection AWWA Manual 36 2 nd Ed. Denver CO p. 40 1999.
5. American Water Works Association Minimizing Earthquake Damage A Guide for Water Utilities Denver CO p. 39 1994.