EHS Management, Health and Wellness, Injuries and Illness

Legionella Prevention for EHS Managers: Watch Your Water System

Last week, the Ford Motor Company reported that trace amounts of Legionella bacteria were found in the water system at their flagship Rouge plant in Dearborn, Michigan. According to the report, the bacteria was discovered “in three locations across the plant—including two bathrooms and the medical department.”  Rather than shut the entire plant down, Ford is going to schedule “on-line disinfection” in the impacted areas of the facility. The news highlights the importance of proper water system management, and environment, health, and safety (EHS) professionals need to get involved. Earlier this year, an industrial hygienist released a new method for analyzing programs to prevent the growth of Legionella bacteria, which cause Legionnaires’ disease and Pontiac fever.

Legionella bacteria

Giovanni Cancemi /

The amount of data generated by buildings’ water management systems can be overwhelming. The analytical method designed by J. David Krause, PhD, evaluates the combined effectiveness of control measures used to prevent Legionella and other waterborne pathogens.

The news analysis model appeared in the April 2019 issue of The Synergist, published by the American Industrial Hygiene Association.

Legionnaires’ Disease, Pontiac Fever

Legionella can cause two types of Legionellosis: (1) Legionnaires’ disease, a serious and potentially fatal lung infection, and (2) Pontiac fever, a less serious infection with milder symptoms similar to seasonal flu.

OSHA has no specific standard for Legionellosis but can cite employers under the General Duty Clause of the Occupational Safety and Health Act if workers are sickened by Legionella exposure on the job.

The Centers for Medicare and Medicaid Services (CMS) added a requirement in 2017 that healthcare facilities take steps to prevent Legionella infections. Patients in hospitals or clients in long-term care facilities who are over the age of 50 with underlying chronic health conditions or suppressed immune systems have a high risk of Legionnaires’ disease infection.

Water System Management

Facility or occupational safety and health managers must regularly perform risk assessments of their buildings’ systems to prevent Legionnaires’ disease or Pontiac fever outbreaks.

Preventing Legionella growth in buildings’ water systems usually involves periodically measuring system parameters, including water temperatures and disinfectant or chlorine levels.

Krause’s analytical model enables facility and occupational safety and health managers to:

  • Evaluate a water system’s susceptibility to Legionella growth and amplification;
  • Prioritize corrective actions for or improvements to systems found to be at high risk; and
  • Validate the effectiveness of control measures.

Using Krause’s model, they can make evidence-based decisions on the allocation of time, personnel, and other resources to manage their water systems for Legionella.

“The cost of implementing a water management program to prevent a Legionnaires’ disease outbreak can be budget busting,” Krause said in a statement, but the costs of an outbreak caused by failing to take preventive steps can be devastating.

Rates of Legionnaires’ disease across the United States continue to rise dramatically:

  • The number of cases has increased fivefold since 2002; and
  • There was a 13 percent increase from 2017 to 2018 in the numbers of cases, according to the Centers for Disease Control and Prevention.

Recommendations for Employers

It can be difficult for building owners and employers to find qualified and properly trained consultants to help manage their water systems. There are no recognized certifications or licenses to prove a consultant is fully trained in finding, assessing, and mitigating Legionella sources in building water systems.

Bad advice during a disease outbreak can prolong outbreak investigation and correction.

“The absolute worst time to find, interview, and vet a consulting expert is during the throes of a disease outbreak,” Krause said in a statement.

Krause recommends contingency planning—finding and vetting consultants with existing relationships with a local public health agency. Consultants should become familiar with a building’s water system before an outbreak occurs.

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