How Often Does Our Facility Need a Legionella Risk Assessment?

There is no single Legionella risk-assessment schedule that applies to every U.S. facility. The appropriate frequency depends on the type of facility, the vulnerability of its occupants, the complexity of its water systems, previous findings, changes to the system, and applicable state or local requirements.

What Determines How Often a Legionella Risk Assessment Is Needed?

The appropriate frequency of Legionella risk assessments in the U.S. is guided by facility-specific conditions, regulations, and best practices.

A facility’s water-management program should also identify how its water systems will be monitored and what actions should be taken when control measures are not working as intended. Learn more about developing a Legionella water management plan.

How Facility Type Affects Risk Assessment Frequency

Healthcare settings, including hospitals and nursing homes, where individuals may be more vulnerable to Legionnaires’ disease, may require more frequent risk assessments. The appropriate schedule depends on the facility, its water systems, previous findings, and applicable healthcare requirements.

Non-healthcare facilities in the U.S. may consider conducting a Legionella risk assessment at least every two years. However, this frequency may need to increase based on the facility’s characteristics, water system changes, previous findings, and local requirements.

When Should a New Risk Assessment Be Completed?

A new or updated risk assessment may be appropriate after changes in the water system or its use. Examples include modifications to the plumbing system, changes in water temperature settings, pressure changes, water-treatment changes, construction, or alterations in the building’s processes or occupancy.

An additional assessment may also be appropriate after repeated monitoring problems, a positive Legionella result, a suspected case of Legionnaires’ disease, or a change in applicable regulations or standards.

If a building tests positive for Legionella, the appropriate response depends on the test result, the facility, and the condition of the water system. See what to do if a building tests positive for Legionella.

U.S. State and Local Requirements

U.S. regulations and guidelines vary by state and local jurisdiction. Facility managers should be aware of the requirements that apply to their location and type of facility. See the state-by-state Legionella information and contact the appropriate regulatory agency or qualified legal professional for specific requirements.

Risk Assessment Versus Legionella Testing

A Legionella risk assessment is different from Legionella testing. A risk assessment examines the facility’s water systems and identifies conditions that may allow Legionella to grow or spread. Testing may be used to investigate a problem or help validate the water-management program, but testing frequency does not automatically determine the frequency of formal risk assessments.

Facilities that need testing should also consider the appropriate testing method, including whether culture or quantitative PCR testing is appropriate. For facilities purchasing testing supplies, see Legionella test kit pricing.

Continuous monitoring and maintenance of water systems are also important. This includes regular temperature checks, system cleanliness, and promptly addressing identified risks. Ongoing vigilance should be combined with periodic formal risk assessments performed by qualified Legionella professionals, including ASSE 12080-certified professionals where appropriate.

Contact Us

Contact Legionella Control Systems with questions about the risk-assessment frequency appropriate for your facility.