Legionella Found on Site: Your First 24-Hours Guide

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October 1, 2022 | Contributors:

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What do you do when a routine water sample comes back positive for Legionella?

Why the First 24 Hours Matter for Legionella Outbreaks

Legionnaires’ disease is caused by Legionella bacteria exposure and kills roughly one in ten of those infected, with higher mortality in healthcare settings where people are more susceptible. Many outbreaks start off with hesitation to take critical action in the opening hours. The sooner you recognize and mitigate the problem, the less chance there is of significant exposure or sickness.

Regulators such as local public health departments judge a response less by the final clean-up and more by how quickly you isolate hazards, notify stakeholders, and document every step. Insurers and plaintiff attorneys will ask for time-stamped logs; if those pages are blank, negligence may be assumed.

Following are day one Legionella response recommendations from FACS for managers of hotels, hospitals, spas, and other public-facing facilities.

Breathe—Then Open Your WMP

Your reaction is going to affect your entire team. If you’ve prepared properly, though, you’ll have a written plan of action. Calm down. Breathe. Then do the following.

  • Pull up your written Water Management Program (WMP). It should spell out who does what when Legionella is discovered.
  • Start a single incident log—spreadsheet, shared folder, or software—and record major decisions and actions taken from this moment forward.
  • Confirm that an analytical laboratory has been engaged, you have copies of the lab’s chain of custody forms, and understand what methods (culture, PCR, or both) will be used to analyze samples. Improperly filled out paperwork can send everyone on a wild goose chase.

Assemble the Incident Response Team

  • WMP Leader (Facilities or EHS) to drive the process.
  • Infection-Prevention or Safety Officer—critical in healthcare and hospitality settings.
  • External Industrial Hygiene Consultant—FACS can guide sample collection, provide remediation expertise, and help with credibility.
  • Communications Lead—crafts internal notices, press statements, talking points.
  • Executive Sponsor/Legal Counsel—authorizes shutdowns, purchases, public notifications.

Have a phone tree pre-loaded in your WMP so no one wastes time hunting for emails.

Isolate and Control Exposure Sources

  • Shut down or bypass any high-risk equipment: cooling towers, decorative fountains, whirlpool spas, hot tubs, therapy tubs.
  • Consider implementing water restrictions until further assessment can be performed. Isolate water service or post clear “Do Not Use” signage on affected showers, faucets, and eyewash stations.
  • Evaluate the need to install point-of-use 0.2 µm filters as a temporary barrier. Filters can allow for users to continue using water safely until sampling and risk assessment can identify the cause.
  • Prepare to perform a risk assessment and collect samples. Gather the equipment, containers, and paperwork in accordance with the WMP.

Note: Point-of-use filters protect only the fixture where installed—don’t mistake them for a whole-system solution.

Notify Authorities and Stakeholders

  • Local Health Department—if cases of illness are suspected, notify the local public health authority if they do not already know.
  • Some jurisdictions, such as in New York City, require notice within 24 hours if counts exceed trigger levels.
  • Some jurisdictions, such as in New York City, require notice within 24 hours if counts exceed trigger levels.
  • Onsite Occupants—tailor messages to patients, guests, spa clients, and employees; offer facts without panic and route medical questions to a single hotline. Ensure occupants can identify symptoms and know when to report them.
  • Medical Surveillance Team—if you are a healthcare facility, alert clinicians to test for Legionella in any new pneumonia cases.

Collect Environmental Samples

  • Work with the WAter Management Team to develop a sampling plan, one may be already developed as part of the WMP. Ensure that representative sample locations are included.
  • Collect water, swab, or bulk samples in high-risk locations or locations where suspected cases may have had exposure.
  • Depending on the risk assessment, you may need to sample potable water (hot and cold, ice), and non-potable water (cooling towers, spas, decorative fountains, etc.)
  • At each point, record:
    • Water temperature
    • Disinfectant residual (free chlorine, monochloramine, etc.) and pH
    • Flow or usage conditions (stagnation breeds Legionella)
  • These field parameters are gold during the root-cause analysis.
  • Submit the samples to the laboratory using their recommended storage and shipment procedures. Ensure the chain of custody form is properly filled out.

Confirm the Positive and Expand Sampling

  • If any samples test positive for Legionella, double-check the original result with the lab. Review the lab report to ensure there are no quality concerns.
  • Review the plumbing plans for the area around where the positive sample was collected. Consider collecting additional samples upstream and downstream of the positive area e to pinpoint the source.

Legionella Outbreak Immediate Remediation Measures

Emergency Disinfection

  • Consider the need to engage a qualified water treatment company to perform emergency disinfection.

Domestic Water System Controls

  • Raise heater set-points to at least 50 °C / 140 °F and ensure hot water delivery points are at least 120F or higher – be sure to consider the risk of scalding.
  • When safe to do so Implement flushing at all fixtures to ensure adequate movement of water. Only perform flushing if the health department has given the ok to do so.
  • Perform cleaning and disinfection or localized remediation of known problem areas.

Cooling Towers

  • Shut down the cooling tower or turn off the fan to prevent drift and lock-out during contact time.
  • Perform an emergency disinfection in accordance with ASHRAE-12 guidance or in consultation with a qualified water treatment vendor.
  • Re-sample 24–48 hours after disinfection.

Spas, Therapy Tubs, Decorative Fountains

  • Drain, clean and disinfect spas, hot tubs, and decorative fountains in accordance with CDC recommended protocols, which typically include: draining, scrubbing, hyperdisinfecting, flushing and refilling.
  • Reopen only after follow-up tests meet WMP targets.

Parallel Track: Health Surveillance & Communication

  • Infection-prevention teams begin active case-finding; clinicians order urinary antigen plus culture on any new pneumonia case.
  • HR tracks sick-leave calls mentioning flu-like symptoms; even mild cases can broaden the investigation.
  • Issue brief, consistent updates daily—same data points, same spokesperson, same channel—to stay ahead of rumours.

 

Call FACS at (888) 711-9998 or contact us online here: https://facs.com/contact-us/.