This document, prepared for U.S. EPA's National Homeland Security Research Center by the American Water Works Association with technical support from CDM, reviews roles and responsibilities among various levels of  government regarding emergency water supplies and seeks to encourage  collaboration and partnership between said levels regarding emergency  water supply planning.

The review of legislative language covering emergency water supply planning demonstrates that all levels of government have some responsibility for emergency water supply planning. All government entities and others responsible for emergency water supplies should coordinate roles, identify approaches, and estimate resources. Preplanning leads to more effective and efficient operations under emergency conditions. This document covers the technical details of this planning; The principal findings are:

1. There are several options for supplying potable water in an emergency. These include water supplied via interconnections with neighboring water utilities, bottled water supplied locally or regionally (a common federal response), and locally produced water. Locally produced water can be obtained by packaging pre-treated water, by using mobile treatment units to inject water into the existing distribution system, or by using mobile treatment in conjunction with water packaging or water tap distribution.

2. Utilities should develop an emergency drinking water plan that considers

    a. the various types of maximum credible events to which they are vulnerable [Note: A maximum credible event is one that can reasonably be expected to   occur but not in combination with unlikely coincidence, such as an earthquake and hurricane impacting South Carolina simultaneously. What event type would cause the most damage and has some reasonable likelihood of happening?];

    b. the number of people potentially affected and the associated duration for a maximum credible event;

    c. the point at which the local capacity to respond adequately would be exhausted;

    d. the potable water alternatives that are the most feasible for the maximum credible event;

    e. what resources would be needed from others, including regional, state or federal agencies;

    f. the process for communicating these resource requests to the various emergency service agencies; and

    g. how to implement the delivery of needed resources.

3. All planning partners would benefit from a state-level aggregation of the resources gaps identified at local levels. Understanding the aggregated state-level resource gap enables planners to include additional sources as a part of the contingency plan. (See Section 9 for a more detailed discussion of relevant the findings.)