Impacts of Global Change on Municipal Water Distribution Systems

The 21^st century will witness widespread global changes due to climatic variation, demographic shifts, population growth and economic transitions. These changes are expected to have a significant impact on the quantity and quality of water resources and the timing of their availability across the globe. These impacts, in turn, will affect the performance and sustainability of the Nation's urban water resources infrastructure. In this context, the national water resources infrastructure includes engineered facilities for purifying and distributing drinking water, for collecting and treating wastewater, and for controlling and mitigating storm water. In anticipation of these far-reaching global changes, the U.S. Environmental Protection Agency is implementing a research program to identify and evaluate innovative approaches to improve the planning, design, operation and maintenance of the Nation's water infrastructure. A key question to be addressed by this program is, "How can the functionality of the Nation's aging water infrastructure be maintained and sustained to protect human health and preserve the environment for future generations in the face of profound global changes?" This paper focuses on the drinking water infrastructure. To help answer this question, the primary stressors and major trends expected to impact the functionality and sustainability of drinking water infrastructure are summarized here. Flexible mitigation and adaptation strategies to help drinking water utilities effectively cope with anticipated changes are outlined at a conceptual level.