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Building Owners… What You Do Not Know About Legionella and Legionnaire’s Disease Can Really Hurt You!
Legionella Bacteria in water supplies poses a serious health hazard to building occupants and a major liability issue for building owners. Want to know more? Then read on…
What is it?
Legionnaire’s disease is an infection caused by air borne exposure to viable Legionella bacteria. It was first identified in July of 1976 when 34 individuals died and 200 others became ill at an American Legion convention in Philadelphia, PA. The Center for Disease Control (CDC) determined that the causative agent was Legionella Pneumophila a gram-negative rod shaped bacteria that was found in the cooling tower water of the hotel where the effected individuals had stayed or visited. The bacteria is fairly ubiquitous in the environment and it appears in water systems both natural and manmade. It is the viable form of the bacteria that can cause disease if an aerosol (think mists e.g. tiny droplets suspended in air) containing the bacteria is inhaled. This causes pneumonia and the fatality rate is an alarming 15% of the reported cases; in environments with immunocompromised individuals, the fatality rate can be a staggering 33%. The number of reported cases has steadily increased since its identification. It is also believed that the cases have been under reported due to the fact hospitals do not routinely check patients for legionnaires disease in all cases of pneumonia.
Why should a building owner be concerned?
The original source of the problem in the 1976 case was identified as the hotel heating ventilation air conditioning (HVAC) system cooling tower. The bacteria propagated in the cooling tower water and it was spread throughout the hotel by the system. Since then cases associated with hot tubs, shower rooms, in door waterfalls, decorative ponds have been reported. In addition, water heaters and building water distribution systems can contribute to the growth of the bacteria. Municipal water systems do not eliminate the bacteria because it can survive routine water treatment practices. Just because you follow your HVAC systems maintenance practice does not eliminate the threat. It could come from something entirely independent of the HVAC system in a building.
   
Liability cases and awards are increasing in this area. In a recent case involving the Celebrity Cruse Line, the damages award was over 15 million dollars.
Although there are no federal, state regulations related to this issue yet, the standard of care is changing. The American National Standards Institute (ANSI) recently published a standard, Prevention of Legionellosis Associated With Building Water Systems, on controlling this issue (ANSI-ASHRAE Standard 188-2015). This year the American Industrial Hygiene Association published Recognition, Evaluation, and Legionella in Building Water Systems. These documents provide detailed guidance on the control and the prevention of this threat. Failure to follow the preventative actions described in these documents can expose building owners to serious liability.
What should you do?
- Determine if there is a potential threat to your building? Do you have any of the systems described in this post? Is your operations and maintenance (O&M) plan addressing the issue?
- Obtain expert competent independent technical help to determine if you need improvements. At a minimum, this would be an individual who is trained and certified to assess the risk. A Board Certified Industrial Hygienist (CIH) who has experience with indoor air quality assessments and is knowledgeable in the industrial hygiene approach to source assessment and prevention would be the logical approach.
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