Maintaining a building’s water system involves more than ensuring that water is available at the tap. Complex plumbing systems can create conditions that allow microorganisms, including Legionella bacteria, to grow and spread.
For many buildings and facilities, a well-designed Water Management Program (WMP) is an important tool for reducing risk and creating a consistent process for monitoring building water conditions.
What Is Legionella?
Legionella is a naturally occurring bacterium that can grow in building water systems under favorable conditions. When contaminated water becomes aerosolized into small droplets and is inhaled, exposure can potentially result in Legionnaires’ disease, a serious form of pneumonia.
Potential sources of exposure can include showers and faucets, hot water systems, cooling towers, decorative fountains, hot tubs, humidification systems, certain healthcare equipment, and other devices that store, circulate, or aerosolize water.
Large and complex plumbing systems can present additional challenges because water temperature, disinfectant residual, water age, stagnation, sediment, scale, corrosion, and biofilm can vary throughout the system.
What Is a Water Management Program?
A Water Management Program is a systematic approach to identifying and controlling conditions that may allow Legionella and other waterborne pathogens to grow or spread.
CDC identifies seven core steps: establish a water management program team; describe the building water systems; identify areas where Legionella could grow and spread; decide where to apply and how to monitor control measures; establish interventions when control limits are not met; ensure the program runs as designed and is effective; and document and communicate program activities.
A WMP should be specific to the facility. A hospital, hotel, senior living community, manufacturing facility, office building, and multifamily property may have very different plumbing configurations, equipment, occupants, and risk factors.
Testing Alone Is Not a Water Management Program
One common misconception is that periodically collecting Legionella samples is the same as having a Water Management Program. It is not.
Environmental testing can provide valuable information and may be incorporated into a WMP as part of program validation. A comprehensive program also evaluates how the building water system operates, including factors such as hot- and cold-water temperatures, disinfectant residual, water stagnation, flushing practices, storage tanks, dead legs and low-use fixtures, sediment and scale, system modifications, construction activities, and changes in building occupancy.
Sampling provides a snapshot of conditions at specific locations and points in time. Water management is an ongoing process.
Which Buildings Should Pay Particular Attention?
Risk varies from building to building, but water management is especially important for facilities with complex water systems or occupants who may be more susceptible to infection. Examples include hospitals and healthcare facilities, senior living and long-term care facilities, hotels, large commercial buildings, multifamily properties, buildings with cooling towers, and facilities with decorative water features or extended periods of low occupancy.
ASHRAE Standard 188 is a key industry standard for legionellosis risk management in building water systems and is commonly used alongside CDC guidance when developing or evaluating a WMP.
A Water Management Program Is a Living Document
Creating a written plan is only the beginning. Building conditions change. Plumbing systems are modified. Equipment is replaced. Occupancy changes. Construction occurs. Portions of a building may sit vacant.
An effective WMP should therefore be periodically reviewed and updated. Facility teams should also maintain documentation demonstrating that monitoring, corrective actions, verification, and other program requirements are actually being performed.
How NoVA Environmental Solutions Can Help
NoVA Environmental Solutions can assist building owners, facility managers, healthcare organizations, property managers, and other organizations with evaluating building water systems and developing practical water quality management strategies.
Depending on project needs, services may include Legionella sampling, building water system assessments, Water Management Program development or review, water quality monitoring, evaluation of potential problem areas, investigation following unusual results or water quality concerns, and sampling for additional waterborne organisms when appropriate.
Managing Legionella risk is not simply about collecting samples. It requires understanding how water moves through a building, identifying conditions that promote microbial growth, monitoring those conditions, and responding when problems are identified.