Toolkit: Developing a Water Management Program to Reduce Legionella Growth and Spread in Buildings

A Practical Guide to Implementing Industry Standards

Many buildings need a water management program to reduce the risk for Legionella growing and spreading within their water system and devices. This toolkit is designed to help people understand which buildings and devices need a Legionella water management program to reduce the risk for Legionnaires’ disease, the key elements of a water management program, and how to develop it.

Toolkit’s quick yes/no worksheet to find out if your building or certain devices in your building need a water management program.

Use the toolkit’s quick yes/no worksheet to find out if your building or certain devices in your building need a water management program.

Provide Feedback

CDC welcomes feedback on this toolkit. Email with your thoughts and suggestions.


Legionella bacteria are typically found naturally in freshwater environments, but can become a health concern when they grow and spread in human-made water systems. Legionella can cause a serious type of pneumonia (lung infection) known as Legionnaires’ disease. Some water systems in buildings have a higher risk for Legionella growth and spread than others. Legionella water management programs are now an industry standard for many buildings in the United States (ASHRAE Standard 188: Legionellosis: Risk Management for Building Water Systems January 2018. ASHRAE: Atlanta).

Scope of the Toolkit

This toolkit aims to provide an easy-to-understand interpretation of ASHRAE Standard 188 to help building owners and managers. They can use the toolkit to help evaluate their water system and devices in their building(s) to determine if they need a program. Then the toolkit explores how to develop an effective water management program if one is needed.

The toolkit includes:

  • A simple yes/no worksheet to determine if an entire building or parts of it are at increased risk for growing and spreading Legionella
  • A basic review of the elements of a Legionella water management program
  • Scenarios describing common water quality problems and examples of how to respond to them to reduce the risk for Legionella
  • Special sections and considerations for those who work in healthcare facilities