As businesses across the country begin to re-open, many will be hypervigilant about the safety of indoor spaces. While stay-at-home orders may be lifting, business owners and their employees may have significant trepidation about the risks of returning to their workspaces and public venues. Building owners and property management companies will be called upon to address concerns about the safety of their tenant spaces and public areas, and the adequacy of measures taken to ensure the protection of building occupants. However, while building owners and property managers must necessarily focus on addressing the concerns arising directly from potential exposure to the COVID-19 virus, they should not ignore other potentially significant concerns associated with reopening their properties. One such concern is the stagnant conditions that may develop in a building’s water system during periods of extended disuse, which can lead to an enhanced risk for the spread of the Legionella bacteria that can cause Legionnaire’s disease, creating potential health risks for tenant, worker, and other user populations.
Legionnaires’ Disease is a serious form of pneumonia that can be fatal, particularly for sensitive populations. Exposure to Legionella can also cause Pontiac Fever, a less severe illness characterized by fever and muscle aches. Legionella bacteria can be found in low concentrations in municipal water and, in a properly managed system, pose little risk. However, if water remains stagnant while a building is shuttered, chlorine levels in the water may dissipate, and naturally occurring Legionella may amplify to harmful levels. Other factors that encourage Legionella to increase to harmful levels include temperature (the bacteria thrive at 80-120○F); the presence of accumulated debris, scale or biofilm; low flows, or “dead legs” in distribution systems; and the presence of algae.
Individuals typically become infected by Legionella through aerosol exposure, with the bacteria entering the lungs in mist form. Thus, likely sources of exposure include showers, hot tubs, decorative fountains, and air conditioning system cooling towers.
As a result of the stay-at-home orders, many hotels, gyms, and office buildings have experienced a significant decrease in occupancy and activity, and many buildings have remained largely empty or completely shuttered for an extended period. Consequently, water use within many of these buildings has also been greatly reduced, and in some cases, completely eliminated, creating the stagnant conditions that could encourage the growth of Legionella bacteria in the buildings’ water systems.
To avoid the risk of a Legionnaires’ outbreak, building owners and property management teams should consider developing and implementing a Legionella water management program before buildings are re-opened or returned to increased occupancy. In fact, the CDC states that “Legionella water management programs are now an industry standard for large buildings in the United States.” Developing a Water Management Program to Reduce Legionella Growth and Spread in Buildings, a Practical Guide to Implementing Industry Standards, at ii, United States Department of Health and Human Services, Centers for Disease Control & Prevention, June 5, 2017 (hereinafter, “CDC Toolkit”.)
Implementation of a proper water management program will minimize the risk of a Legionnaires’ disease outbreak. Each building will require a tailored plan, but the following information will assist initial planning efforts.
First, determine whether and which parts of your building are at increased risk for Legionella. To do so, consider the following:
- Are workers, patients, residents, or guests housed overnight on your premises?
- Does your building have more than 10 stories (including basement levels)?
- Does your building have a cooling tower?
- Does your building have a hot tub?
- Does your building have decorative fountains?
- Does your building have a centrally installed mister, atomizer, air washer or humidifier?
CDC Toolkit at 2.
The CDC recommends that any building which answers “yes” to any of the above questions develop and implement a water management plan.
If your building meets one or more of these criteria, you should consider developing a water management plan. If all or a portion of your building has been vacant or mostly empty during recent months because of the stay-at-home orders, before reopening the building, you should consider conducting an assessment to determine whether conditions are present which may create a Legionella risk. For more information on assessing your building after closure, see the CDC’s Guidance for Reopening Buildings After Prolonged Shutdown or Reduced Operation, updated May 7, 2020. If indicated, building water systems should be examined by a professional to determine if Legionella are present above applicable standards.
If Legionella are detected in one or more areas above applicable standards, treatment will be required. An effective treatment plan will likely include one or more of the following disinfection methods: mechanical cleaning, thermal treatment (at a temperature of 160○F), chemical treatment and biofilm control. Each of these methods have their own benefits and challenges. Therefore, it is important that a qualified water treatment professional be engaged and coordinate with the building maintenance team to develop a tailored treatment plan.
Our collective experience with COVID-19 has heightened our awareness of health and safety standards and has highlighted the need for thoughtful and rigorous attention to our indoor spaces. By taking measures to assure the proper condition of building water systems, building owners and operators can avoid potential liabilities and give returning tenants, workers, and users confidence that they can return to their spaces safely.