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During an Event: Initiating an Advisory

Identify the Situation and Collect Facts

Drinking water advisories are issued for reasons identified in federal or state regulations or by decisions made by the water system. The situation and characteristics of the contaminant(s) of concern determine what type of advisory to distribute:

Icon Key

tool icon Tools and Templates

resources icon Resources

  • Informational
  • Boil Water
  • Do Not Drink
  • Do Not Use

Use the Essential Information list to collect data and develop communication materials.

Notify Your Drinking Water Primacy Agency

Each state that has primacy specifies particular mechanisms for state notification. Be familiar with your water system’s protocols for notifying your primacy agency. See Appendix B: Online Resources, Primacy Agency.resource icon

Decide to Issue an Advisory

Work with senior management and follow your communication SOP in making the decision to issue an advisory. Use your best professional judgment.

Identify the Geographic Boundaries


A key component of a drinking water advisory is to communicate clearly the area affected. Many customers do not know which water system provides their service and broadcast media usually reach a large audience beyond the affected area.

Clearly describe the boundaries of the affected area using street names, place names, and well known reference points.

Figure 5: Example of a Simple Map to Designate an Area Affected. A street map showing in the affected neighborhoods and streets with a red overlay. Displays how widespread the affected area is geographically.

Figure 5: Example of a Simple Map to Designate an Area Affected by a Drinking Water Advisory. Click the image for a larger version.


Maps help illustrate the affected area. Water systems can generate maps using internal or online mapping tools (e.g., geographic information system [GIS]). These maps can be posted on agency websites, or distributed electronically or as printed material. Update the map as the situation changes.

Notify Your Internal Staff and External Partners

Activate your internal communication SOP. Use information collected to brief staff. Depending on the situation, also brief your partners:

  • Wholesale, consecutive, and neighboring water systems.
  • Public health department.
  • Critical customers (see Critical Customer Checklist tool icon [DOC - 1 page] to assist in identifying at-risk populations served by a water system).
  • Public officials.
  • Emergency management.
  • Community organizations.
  • Businesses, childcare facilities, correctional facilities, food service, health care providers and facilities, and schools.

Provide Call Center Data Checklisttool icon [DOC - 1 page] to call center or customer service staff and partners.


Clearly communicating the boundaries of affected areas also requires careful consideration of verbal descriptions so that spokespersons, radio, and other media can briefly but accurately depict the service area affected.

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