New York City health officials reported a growing cluster of Legionnaires’ disease cases in the Harlem area, resulting in multiple hospitalizations and deaths. The outbreak was traced to contaminated building water systems, underscoring the critical need for proactive Legionella risk management in facilities with cooling towers, plumbing systems, and water features including indoor and outdoor fountains, ornamental ponds, decorative water walls or cascades, reflecting pools, and splash pads.
What Causes Legionnaires’ Disease in Building Systems?
Legionella pneumophila is a bacterium that occurs naturally in freshwater environments. Under favorable conditions, such as warm, stagnant, or standing water, the bacteria can multiply to levels that pose a health concern. When present in a building water system, Legionella can become aerosolized through devices such as showers, cooling towers, or decorative fountains. Individuals in close proximity may inhale airborne water droplets containing the bacteria. Inhalation or aspiration of these droplets can cause Legionnaires’ disease (legionellosis), a severe form of bacterial pneumonia, or Pontiac fever, a milder, nonfatal respiratory illness. Those at elevated risk include adults aged 50 and older, current or former smokers, and individuals with certain underlying health conditions such as cancer, chronic lung disease, diabetes, kidney or liver failure, or compromised immune function.
Legionnaires’ disease is a waterborne illness that is not spread from person to person; however, outbreaks can carry significant health, legal, and financial implications for building owners.
How Can Building Engineers Prevent Legionella Contamination?
To reduce the risk of Legionella outbreaks, the CDC advises implementing a comprehensive water management plan (WMP), maintaining water temperatures that inhibit bacterial growth—typically keeping hot water above 124°F (51°C) and cold water below 68°F (20°C)—and routinely cleaning and disinfecting water systems and devices such as cooling towers, hot tubs, and humidifiers.
Following implementation of a site-specific WMP, RHP Risk Management (RHP) experts, proficient and trained in providing Legionella water testing services, can assist with WMP validation plan either on a quarterly, bi-annually, annual or one-time sampling basis, by the collection of water samples analyzed by a CDC-elite Legionella laboratory testing facility.
Contact RHP Risk Management for Comprehensive Water Management Plan Support
RHP Risk Management’s ASSE 12080 certified professionals develop site-specific WMPs in accordance with ASHRAE Standard 188, CDC Toolkit guidance, and CMS requirements; conduct Legionella risk assessments, sampling, and outbreak investigations; and provide regulatory, legal, and operational support to help facilities of all sizes proactively manage risks, ensure compliance, and respond effectively to incidents.
RHP professionals bring extensive expertise to the investigation of buildings and suspected sources of Legionella, working closely with clients to develop tailored, site-specific methodologies and plans grounded in sound scientific and risk-based principles. We partner with organizations to address urgent concerns, clearly communicate identified risks, and outline practical, effective solutions to guide next steps with confidence.
Contact RHP Risk Management to schedule a consultation or request a review of your current plan. Proactive action today protects building occupants and operations tomorrow.