Legionella-related illnesses should be a concern for many businesses and facilities that have been closed temporarily due to the COVID-19 pandemic. As we approach the warmer weather when demands of cooling and water consumption increase, the need for system maintenance is enhanced. So, we decided to re-visit the HETI Horizons we published in November 2018 on the need for Legionella Water Management Plans – updating it in light of the reopening and reoccupation of these facilities in the coming months.

Legionella is a bacterium that causes a type of serious lung infection known as Legionnaires’ disease, as well as a less serious illness called Pontiac fever. It thrives in a narrow temperature range that includes the human body temperature. According to the Centers for Disease Control and Prevention (CDC), health departments reported approximately 10,000 cases of Legionnaires’ disease in the United States in 2018. Unfortunately, about 10 percent of people diagnosed with this disease will die – with the majority of fatalities occurring among the elderly and those with compromised immune systems. Since the symptoms of Legionnaires’ disease are similar to other illnesses, such as COVID-19, the true number of cases may be undiagnosed and thus underestimated by the CDC. Due to the large number of Legionella cases that normally occur each year and the opportunity for a higher incidence rate due to the COVID-19 pandemic, Legionella water management programs should be an industry standard for large buildings in the U.S.

Common Sources of Legionella

Legionella is found naturally in freshwater environments, like lakes and streams; but generally the low amounts in freshwater do not lead to disease. Legionella can become a health problem in building water systems when it multiplies and becomes aerosolized into small droplets that can be breathed in by facility occupants and nearby community members. Outbreaks occur most often during the warmer summer months, when buildings start air conditioning systems that have been turned off for long periods. In response to the COVID-19 outbreak, countless businesses have been shut down for more than 30 days – with facility water systems idle since their closure. Many of these buildings did not have water management programs or operate their air conditioning systems on a regular basis. This allows water to sit in plumbing system legs where biofilms may grow.

Buildings with increased risk for Legionella problems include healthcare facilities, buildings with more than 10 stories, retirement homes, assisted living facilities, hotels, and high-rise apartment buildings. Outdoor water parks, fountains and other water features are susceptible to bacterial growth as well. Legionella grows best in building water systems that are not well maintained. Building water system components often associated with Legionella growth and spread include cooling towers, hot tubs or spas, decorative fountains, central humidifiers, sink faucets, and shower heads. Keeping Legionella out of building water systems is key to preventing the occurrence of infections among building occupants. Due to the vacant buildings and lack of maintenance/use of the facility water systems during the COVID-19 pandemic, Legionella bacteria water concentrations may have increased.

Elements of an Effective Water Management Program

Development and maintenance of a water management program require continuous oversight and several key steps – including:

• Forming a water management program team. Typical members could include building owners, building managers/administrators, facility maintenance/engineering employees, Certified Industrial Hygienists, water treatment consultants, microbiologists, and state or local health officials. COVID-19 facility re-occupation plans should include a review of the facility water systems by the water management program team.
• Documenting the current building water system components using text and flow diagrams. This would include information on the water supply source, water distribution  methods, water heating methods, and  diagrams that link the flow of water among these components. Text and flow diagrams can be created by the water management program team or with assistance from a third-party consultant.
• Identifying areas in the building water systems where Legionella could grow and be distributed. The previously developed text and flow diagrams are often used for this step to document a hazard analysis for the water system. This assessment should address areas in the system that would normally not be considered, due to COVID-19 related building vacancies.
• Determining the location and type of control systems necessary to effectively control Legionella. This step often requires assistance from third-party consultants. Providing the consultants with water system components, flow patterns, and suspect Legionella sources provides important information for the determination of control methods for specific water systems. In many instances, multiple control methods are implemented.
• Establishing methods to evaluate the controls. This often requires assistance from third-party consultants as well.
• Documenting monitoring method and frequency, which may be affected by system maintenance, renovations, equipment failure, and water service interruptions. Training should be provided for any personnel responsible for the operation and evaluation of the water system controls. Control measures may change as facilities become fully occupied and operational. Facilities with revised COVID-19 occupancy and operational limits may require extended or permanent implementation of control measures.
• Determining the response measure to be taken if Legionella concentrations exceed predetermined allowances. Since building water systems are continuously changing, Legionella water concentrations will also fluctuate. Corrective measures should be planned to handle instances when the concentrations exceed the allowable limits.
• Developing systems to monitor the water management plan operation and effectiveness. Periodic inspections and third-party audits are often used to monitor plan operations.
• Documenting program maintenance, including inspection activities and corrective measures. Documentation should be maintained at the field location and/or corporate office.
• Communicating program status and incidents to affected personnel/ occupants. E-mails, notices, bulletin boards, and periodic training are effective communication methods.

Evaluating the Operation and Effectiveness of a Water Management Program

Once the Legionella Water Management Plan is developed and implemented, verification and validation of the plan is required. Verification and validation of each part of the water system control should be conducted by personnel not directly affiliated with the process being inspected. It is prudent to utilize third-party consultants to perform complete verification that the program is being implemented as designed.

Summary

So how do facilities reduce the risks associated with Legionella contamination of building water systems – especially with the challenges resulting from the COVID-19 pandemic? The first step is to develop written, facility-specific plans for managing building water systems – focused on the control of Legionella. The development of these programs will require an assessment of the facility operations, review of existing facility water supply systems, and determination of appropriate control measures. After development and implementation of the plan, facilities should evaluate the program to determine if they are effectively controlling Legionella water concentrations. Finally, facilities should document the maintenance of the program, water system alterations, and communications with building occupants.

HETI…Helping Control Legionella

HETI can assist facilities facing the challenges discussed in this newsletter – in the areas of prevention, testing and response. We can provide building assessments, assistance in the development of Legionella Water Management Plans, and testing/inspections to verify and validate the effectiveness of a facility’s plan.