Preventing Legionella Made Simple

Legionella can be life threatening and should be taken seriously. Luckily, identifying the source of Legionella cases is relatively simple, as are the measures taken to prevent the bacteria.

When someone comes to a clinic or hospital because they're feeling ill and eventually test positive for Legionnaires' disease or Pontiac Fever, medical staff will generally inquire where the sick person has been. Since Legionnaires' disease outbreaks are so uncommon, healthcare facilities can deduce that any other local reports of a few patients testing positive in that area are likely related. Hopefully through enough probing, healthcare experts are then able to identify the location of the possible source and tests are conducted on the water system of the location in question. Ideally, the tests would help to identify the exact source and result in treatment.

Obviously, it's better to prevent a bacteria from causing an illness than it is to treat someone who is already infected. To prevent sickness caused by Legionella, experts offer suggestions.

Trinks recommends installing newer synthetic substrate material into the HVAC and air handling units that are capable of removing Legionella bacteria. He says such filters can block microbes sized 0.1 micrometers and above. For context, Trinks says COVID-19 is believed to be 0.128.

In restrooms and locker rooms, Trinks advises spraying an organosilane onto shower heads. He says this reduces the chances the bacteria comes into contact with a person while showering.

Before facilities are reopened for returning workers and customers, it's suggested that managers check for the presence of Legionella and other hazards, such as mold, lead and copper contamination, which can be caused by corroded plumbing.

Garrett suggests checking for mold regularly, but especially after days to months of inactivity. He says a prolonged period of inactivity can be classified as a few weeks or months for Legionella, and could be anywhere from a few hours to months for lead and copper issues, depending on the plumbing and other water-specific factors.

Rackl advises that commercial facilities follow the lead of many hospitals, nursing homes and hotels, and implement a water management plan that limits the growth of Legionella in a building's water systems. The development of such a plan involves finding out what locations within a facility have the potential to facilitate Legionella growth so that the quality of the water in those systems can be monitored and that management practices can be implemented.

"Maintaining building potable water and HVAC systems to limit ideal growth conditions is critical in preventing Legionella incidents," says Rackl.

Experts suggest browsing the CDC's website to read more about Legionella and to scan its resources regarding the development of a water management plan. Right now, the CDC has a toolkit on developing a water management plan, which can be downloaded at https://www.cdc.gov/legionella/downloads/toolkit.pdf.

Another resource was recently made available by The American Water Works Association and International Association of Plumbing Mechanical Officers. "Responding to Water Stagnation in Buildings with Reduced or No Water Use" can be downloaded at https://www.awwa.org/Portals/0/AWWA/Government/20201001FrameworkforBuildingManagersFINALDistCopy.pdf.