The US Environmental Protection Agency (EPA), as part of its overall municipal water efficiency program, is concerned about the issue of water system leakage because of an increasing number of reports of substantial leakage and other losses from US water systems. EPA's interest can be categorized in four areas: public health impacts; environmental impacts; sustainability; and, infrastructure. This paper will elaborate on EPA's areas of interest concerning water system leakage and summarize current research and programmatic actions the Agency is taking to promote efficient water delivery. Includes 7 references, figure.