Preventing Waterborne Risks In Times of Crisis — Legionella Special Session Brings Together Experts
The elevated risk of Legionella contamination in closed facilities during the COVID-19 pandemic has highlighted the need for water safety plans for buildings of all sizes and functions to prevent further public health hazards.
A virtual special session of the annual Legionella Conference, Prevention of Disease and Injury From Waterborne Pathogens During an Emergent Health Crisis, has been set for March 9-10 to bring together water industry leaders and public health officials to address how we can better respond to water-related challenges during a major crisis.
Organized by NSF Health Sciences, LLC, an NSF International company, and the National Environmental Health Association (NEHA), the special session will be headlined by keynote speakers from the U.S. Centers for Disease Control and Prevention (CDC) who will present new Legionella control tools and discuss the impact of the COVID-19 pandemic on Legionnaires’ disease incidence, testing, and reporting.
Water usage in commercial and public buildings dramatically dropped when the pandemic forced sudden closures last March. The prolonged period of stagnant or low-flow water has created an optimal atmosphere for Legionella growth in the biofilm of plumbing systems.
The sometimes deadly Legionnaires’ disease can be contracted when people inhale mists of water contaminated with Legionella bacteria. The number of documented cases of this acute form of pneumonia has risen to record levels — 9,933 in 2018, according to the CDC, with the actual number of suspected underdiagnosed cases believed to be as high as 70,000 annually, according to a 2020 report by the National Academies of Sciences, Engineering and Medicine.
Legionella outbreaks from building water systems are preventable with proper maintenance and safety plans.
A Q&A with conference organizer Chris Boyd, General Manager of NSF Health Sciences’ building water health program, highlights the safety concerns and what the special session hopes to achieve. As a former public health official in New York City, Boyd led the response to the 2015 Legionella outbreak, the largest in NYC’s history.
The record number of Legionella cases was already concerning before the pandemic and was associated with thousands of deaths every year. Are we seeing any trends in the disease surveillance data that indicate cases are continuing to rise during the pandemic?
There is a lag in the official reporting of Legionella disease at a national level in the United States as the state health agencies are responsible for confirming cases of disease and presenting this information to the CDC, and we will not know until much later in 2021 if states are identifying increased cases. We have seen some early research showing co-morbidities between COVID-19 and Legionella cases, and there was broad direction to the medical community to screen patients for both COVID-19 and Legionella.
In anticipation of the increased risks of infection, national and state public health agencies across the world issued direction to building owners and managers to take steps to reduce the opportunity of Legionella amplification during low use periods. A number of high-quality guidance documents from federal and state public health agencies and other organizations such as NSF and AWWA (American Water Works Association) were created to assist building owners and managers on controlling risks when reopening, and we hope the statistics will bear out the effectiveness of this guidance.
There have been cases of Legionella detection in buildings that have been largely closed or experienced a prolonged period of stagnant water reported in the press, which is fully expected. Many buildings or parts of buildings remain closed a year after being shut down, creating higher risks if they haven’t been properly maintained.
There is consensus among public health agencies across the globe that no- and low-occupancy rates can amplify Legionella risks. How should our water quality and disease surveillance strategies change in response to tens of thousands of buildings being dramatically impacted by COVID social distancing?
What we know is that most buildings do not have water management plans in place and building owners or managers are not actively taking steps to ensure their building water systems are not a source of disease during normal operating conditions. In much of the world, there is no expectation that building owners manage their water systems to ensure they do not cause disease.
The pandemic has underscored the critical need for every building to have a solid water management plan that specifically addresses water quality surveillance and disease prevention measures. Absent proactive water management controls and active monitoring of water quality parameters, we will continue to use people as the proverbial “canary in the goal mine” to determine when actions should be taken to reduce disease.
Building water systems account for nearly all Legionella cases and deaths, which the CDC estimated as being a $823 million annual drain on the U.S. economy annually looking at data from 2014, and the cases have rapidly increased. As we move toward a post-pandemic world, we need to support building owners, develop sustainable risk management practices, and build data transparency into whether risks are being effectively managed, allowing for proactive response from private and public sectors prior to the onset of illnesses and potential deaths. These plans should include emergency shut-down and re-opening procedures for facility water systems, disinfection controls, specifics for how and when and from where within the distribution system water samples will be collected and tested, as well as accountability and record-keeping measures.
While the process may seem daunting, the public sector can speed the adoption of proper management strategies and develop data collection and management systems that provide for integrated and transparent surveillance of risk. Working with the Urban Sustainability Directors Network and 20+ public agencies, NSF presented a model for how to achieve consistent and transparent management of risks from cooling towers, which could be applied to all building water systems.
How will dialogue at the special session address these new pandemic-related risks?
The virtual platform for the special session offers the opportunity for a highly engaging discussion for attendees — leaders and professionals from health care, water utilities, manufacturing, and hospitality, as well as health departments and regulators — to come together and discuss how we approach water safety, planning, and emergency response during a health crisis.
Concurrent breakout sessions, panel discussions, and case study reviews will cover topics such as water management in health care, hospitality, commercial, and industrial facilities during a crisis; sampling strategies for Legionella during and after an extended shutdown; design, commissioning, construction, and renovation to prevent biofilm growth and other hazardous conditions; safe reopening and state-issued COVID-19 guidance related to water management; resiliency strategies for returning to normal operation; and emergency planning and risk management.
The conference will also highlight new technology to help prevent further public health hazards, and our CDC keynote speakers will discuss the CDC’s new Legionella prevention tools.
The global pandemic dramatically changed water use patterns, particularly in central business districts. How are water utilities responding to the resulting water quality challenges and educating their customers about risks arising from no and low water demand?
The Legionella Conference Special Session on March 9th and 10th includes critical participation of the American Water Works Association and its Committee on Premise Plumbing to discuss the role of water utilities to help address the risks to drinking water distribution and building water systems.
The impact on water use patterns from the global pandemic is unprecedented, and we have seen a range of responses from water utility systems to address the changes in use patterns. At the conference, we will learn about some of the educational strategies used by water utilities to inform building owners of the risks from reduced water demand. We will also learn how some water utilities used real-time water consumption data to identify buildings with dramatic reduction in water demand. This proactive use of water consumption data allows water utilities to engage directly with customers with low water demand and encourage them to take steps to reduce short- and long-term risks of Legionella amplification and corrosion.
Water utilities also took steps to address the impact of reduced water use on water quality and maintenance of critical disinfectant residuals. To address the loss of disinfectant residual due to increased residency time, some water utilities increased the disinfectant levels at their entry points to the distribution system. Using real-time water consumption data and increased water quality monitoring, water utilities addressed isolated declines in water quality and the loss of disinfectant residual through targeted flushing and supplemental disinfection strategies.
The ability of water utilities to understand and respond to the COVID-19 global pandemic was supported by their previous emergency planning efforts designed to address operational upsets or natural disasters that dramatically impacted the functioning of the water supply. Proactive water utilities leveraged these existing plans to address water quality and consumer risks associated with the global pandemic.
One of the challenges crystalized by the global pandemic in the U.S. and Canada, in particular, is that once water crosses the meter and enters the building, there are few, if any, regulatory requirements in place to ensure the water is not a source of disease. Will the current status quo change as a result of a global pandemic that resulted in the CDC, the EPA, and many state agencies redoubling their efforts to educate building owners about Legionella risks?
In my view, this is the million-dollar question. The risks related to building water systems are generally ignored across North America by public health and environmental authorities. While there are federal and state drinking water quality standards that drive billions of dollars in investment on water quality risks with much lower fiscal and public health impacts compared to Legionella, there is no regulatory framework once the water crosses the meter to drive consistent organization and investment in solutions. The CDC recognizes that Legionella exposure is rapidly rising with a more than eightfold increase in reported cases since 2000, is the source of nearly all waterborne outbreak deaths in the United States and has a significant public health and fiscal impact. However, the CDC is not a regulatory body and can only offer technical support and suggestions to state and local governments.
The EPA has investigated secondary disinfection technologies for controlling Legionella risks and invested in research looking at the relationship between opportunistic pathogens and premise plumbing. However, it is not clear how and/or if the EPA will articulate a regulatory strategy or vision for how to address the degradation of municipal water after it crosses the meter that is killing thousands every year. The National Institute of Standards, ASPE, and IAPMO are investigating code changes to address the mismatch between plumbing codes and water conservation efforts that has resulted in dramatic increase in water residency in premise plumbing, but these efforts are years off and would not address the risks related to existing buildings. In sum, there is currently no clear path forward for a national strategy for addressing likely thousands of largely preventable deaths every year from improperly maintained building water systems in North America.
The global pandemic highlighted the challenge faced by cities and states that do not have any national framework for preventing waterborne disease associated with building water systems. My hope is that the coordination and technical assistance provided by the CDC and EPA during the pandemic will jump-start discussions on creating a national environmental and public health strategy for preventing waterborne disease in building water systems. For that to happen, however, we will need environmental and public health advocates and professional associations like the AWWA to take leadership positions in organizing the dialogue and building broad consensus for the path forward.
In my view, that requires us aligning our expectations for risk management with those that have direct responsibility for managing the building water systems. This is the approach taken in much of Europe and Australia, for example. In the U.S., we have seen examples of where responsibility is pressed upon the water utility, which has a crucial role, but no ability to control risks associated with individual building water systems. This approach aligns with how we manage risks from other critical life and safety building systems like fire sprinklers, boilers, elevators, and escalators.
The pandemic has underscored the importance of properly designed and implemented water management plans. What are the trends in this area and what are some of the essential factors that drive the success of a water management plan?
The health and safety of tenants and customers cannot be properly protected without a solid water management program. Effective water management plans should describe all water systems within a building, the flow of water through those systems, how risks are managed and who is responsible for each required action in the plan. Plans should address:
- Flow of water – This includes a successful flushing program that includes all parts of the building with low or no consumption.
- Control of biofilm with disinfectant – This includes measuring the incoming disinfectant residual from the utility and ensuring the flushing regimen keeps the disinfectant circulating throughout the plumbing system.
- Managing water temperature – Legionella proliferates between 77°F to 108°F, so it is critical that steps are taken to control temperatures in hot water storage units and hot-water piping systems.
- Shut-down and start-up procedures – Some water systems, such as cooling towers, decorative features, and pools, can be shut down temporarily while others must remain in operation. Systems shuttered for an extended period need to be carefully managed to ensure continued application of biocides and that water continues to be recirculated and every drop sees every biocide feed.
- Storage tanks – Water in drinking water storage tanks should be turned over at least every 72 hours and tanks should be kept at the lowest operational level, enough to renew water every 24 to 72 hours.
- Record keeping – Records must be accurate and defensible.
- Water quality surveillance – Testing water quality from strategic points within the building system is critical, especially in times of crisis.