Key points
- Remediation is nearly always indicated whenever an outbreak of Legionnaires' disease occurs.
- Remediation may also be indicated when control measures are ineffective or routine results indicate poor Legionella control.
- Remediation may also be appropriate in response to unexpected events (equipment failure or acts of nature) that disrupt the water system.
Remediation options
Remediation options can include:
- Hyperchlorinating the potable water system
- Draining and scrubbing devices
- Superheating and flushing a simple device
Note, ASHRAE Guideline 12 recommends against superheating as a remediation method for potable water systems.
Recommendations
If an outbreak or illness is suspected, test in conjunction with public health in order to:
- Confirm the presence of Legionella before performing remediation.
- Confirm elimination of Legionella after remediation activities.
Tailor the remediation to structural characteristics of the facility and circumstances of the outbreak.
Base decisions on findings from the
- Environmental assessment and sampling results
- Epidemiologic findings of the investigation
It may sometimes be necessary to hire a consultant with Legionella-specific environmental expertise to help make decisions about or perform remediation.
Content Source
National Center for Immunization and Respiratory Diseases; National Center for Environmental Health
About This Page
Published: May 15, 2024
Updated: January 21, 2026
This page was last updated on this date. Updates may include minor edits, image changes, or other modifications to page content.
Reviewed: April 17, 2024
The information on this page was last reviewed by subject matter experts to ensure accuracy.