This webpage lists the Instructions (template notices) and required (mandatory) public notice health effects language that a public water supply system must use when notifying the public of a violation that has happened in the system. 

There are different types of violations: maximum contaminant level violation, maximum residual disinfectant level, treatment technique violation, monitoring violation, and reporting violation.

  • A maximum contaminant level (MCL) violation occurs when the level of a contaminant in drinking water delivered to any user of a public water supply system is above the maximum permissible level. 
  • A maximum residual disinfectant level (MRDL) violation occurs when the level of a disinfectant added for water treatment is above the maximum permissible level at a consumer's tap in the distribution system.
  • A treatment technique (TT) violation occurs when a treatment process required to minimize the level of a contaminant in drinking water is not maintained. 
  • A monitoring violation (MV) occurs when a required compliance sample was not collected during the specified time period. 
  • A reporting violation (RV) occurs when a required reporting activity is not completed within the specified time period.

Public notice is also required when a health advisory is exceeded for a contaminant that is not otherwise regulated, such as manganese.

Back to top

Community Public Notice Instructions

Back to top

Non-community Public Notice Instructions

Back to top

Cylindrospermopsin & Microcystin Public Notice

Back to top

Required Public Notice Language

Back to top

Main Break & Depressurization Guidance

Back to top

Additional Resources

Back to top