The Environmental Protection Agency's Office of Water, in cooperation with the Association of State Drinking Water Administrators [ASDWA], has prepared suggested measures for drinking water systems to guard against terrorist and security threats. These measures are consistent with the Department of Homeland Security's color-coded advisory system beginning with green, which denotes low risk of terrorist/security threats and increasing in seriousness through blue, yellow, orange and red.  

The Agency took a two-pronged approach in disseminating these precautionary measures.

• First, through the Association of State Drinking Water Administrators [ASDWA], each state's drinking water program managers has received these guidelines for determining how best to coordinate these measures with other instructions developed by the state. This EPA document is intended to be complementary and does not override or replace the states' guidance.  The Water Division of the Michigan Department of Environmental Quality,  in cooperation with the Security Committee of the Michigan Section of the American Water Works Association, has determined that the color-coded threat level suggested measures for drinking water systems, as prepared by EPA and ASDWA, are appropriate for distribution to Michigan drinking water systems.  These color-coded terrorist threat level measures will be distributed to Michigan drinking water systems in the near future.
• Second, these guidelines have been posted at the Water Information Sharing Analysis Center [Water ISAC] secure Internet web site at www.waterisac.org.  This internet web site provides information to drinking water utilities on a variety of critical water infrastructure protection activities.