Overview of Water Management Programs
Read about various illnesses, including Legionnaires’ disease, in CDC’s first estimates of the impact of waterborne disease in the United States.
Water management programs identify hazardous conditions and take steps to minimize the growth and transmission of Legionella and other waterborne pathogens in building water systems. Developing and maintaining a water management program is a multi-step process that requires continuous review. Such programs are now an industry standard for large buildings in the United States.
Seven key elements of a Legionella water management program are to:
- Establish a water management program team
- Describe the building water systems using text and flow diagrams
- Identify areas where Legionella could grow and spread
- Decide where control measures should be applied and how to monitor them
- Establish ways to intervene when control limits are not met
- Make sure the program is running as designed and is effective
- Document and communicate all the activities
In general, the principles of effective water management include:
- Maintaining water temperatures outside the ideal range for Legionella growth
- Preventing water stagnation
- Ensuring adequate disinfection
- Maintaining devices to prevent scale, corrosion, and biofilm growth, all of which provide a habitat and nutrients for Legionella
Once established, water management programs require regular monitoring of key areas for potentially hazardous conditions and the use of predetermined responses to remediate such conditions if the team detects them.
Each program has to be tailored for each particular building at a particular point in time. Building factors to take into consideration include:
- Structure and size
- Location and surrounding conditions
- Unique areas of risk for Legionella growth and spread
- Susceptibilities of the people found within
Options may vary depending upon state and local building codes, water treatment regulations, healthcare accreditation and survey requirements, and public health reporting requirements. For example, anti-scald regulations may limit maximum allowable water temperatures.
In some settings, such as hospitals and other large buildings with complex water systems, you need a water management program for the entire building. In other settings, such as small buildings with simple water systems, you may only need a water management program to cover the devices that aerosolize water. Examples of these devices include fountains, hot tubs, cooling towers, and respiratory equipment intended for nebulization.
You can use this worksheet to identify buildings and devices at increased risk for Legionella growth and spread that should have a water management program according to industry standards (ASHRAE Standard 188external icon).
In 2016, CDC released a toolkit to provide practical guidance on how to implement industry standards by identifying areas or devices in buildings where Legionella might grow or spread to people. You can find guidance specific to healthcare facilities in this toolkit.
A consultant with Legionella-specific environmental expertise may sometimes be helpful in implementing and operating water management programs.
- Guidance for Reopening Buildings After Prolonged Shutdown or Reduced Operation
- Infographic: How Legionella Affects Building Water Systems and People
- Preventing Legionnaires’ Disease: Environmental Health Expertise Is Key pdf icon[3 pages]
- What Owners and Managers of Buildings and Healthcare Facilities Need to Know about Legionella Water Management Programs
- What Owners and Managers of Buildings and Healthcare Facilities Need to Know about the Growth and Spread of Legionella
- Preventing Legionnaires’ Disease: A Training on Legionella Water Management Programs
- Waterborne Disease in the United States