The Public Notification (PN) rule requires public water systems (PWSs) to alert consumers to potential health risks from violations of drinking water standards and to tell them how to avoid or minimize such risks. The revised PN Rule, published in the Federal Register on May 4, 2000, modifies the minimum requirements PWSs must meet regarding the form, manner, frequency, and content of public notices. States with primary enforcement responsibility (primacy) must revise their drinking water programs by adopting regulations that are at least as stringent as the revised public notification requirements as soon as possible but no later than two years after promulgation of the final rule (by May 6, 2002). This guidance is designed to assist States in applying for primacy revision for the Public Notification Rule. Information on the primacy revision process-the procedures, timeframes, and content for submission of a State primacy revision application package-are outlined in this document. This guidance is also intended for use by EPA Regions as they review State primacy revision application packages. Public notification of drinking water violations provides water systems with a means to protect public health, build trust with consumers through open and honest sharing of information, and establish an ongoing, positive relationship with the community. Public notice can also help consumers understand rate increases and support increased funding for drinking water treatment and protection. EPA believes the new requirements make it easier for systems to provide consumers with more accurate and timely information on violations and the seriousness of any potential adverse health effects.