As buildings continue to reopen following pandemic-mandated shutdowns, the Centers for Disease Control and Prevention (CDC) has identified the possibility of increased cases of Legionnaires’ disease. We learned this the hard way when dealing with complex water heater issues… This is the result of stagnant or standing water in a building’s unused or underused plumbing system, which allows Legionella and other biofilm-associated bacteria to grow and spread. Consequently, Legionella bacteria has become a serious concern for the plumbing industry and should be proactively addressed to double-check that the health and safety of building occupants.
Now, this might seem counterintuitive when dealing with water heaters…
Water Heater Types
Conventional Storage Tank Heaters: These work by heating and storing a large volume of water, typically between 30 and 80 gallons, within an insulated tank. The water is kept at a consistent temperature, usually between 120°F and 140°F, to meet hot water demands. While storage tank heaters are a reliable and cost-effective option, they can present a higher risk of Legionella growth if the water temperature is not properly maintained.
Tankless Water Heaters: Also known as on-demand water heaters, these systems heat water as it is needed, rather than storing a large volume. Tankless heaters can provide a continuous supply of hot water, but they may struggle to keep up with high-demand scenarios. Proper sizing and installation are crucial to double-check that the water temperature remains within the safe range to prevent Legionella proliferation.
Solar-Powered Water Heaters: These systems use the sun’s energy to heat water, reducing the reliance on traditional energy sources. While solar water heaters can be an energy-efficient and environmentally-friendly option, they may face challenges in maintaining the necessary water temperature to inhibit Legionella growth, especially in cloudy or cold climates.
Water Heater Maintenance
Inspecting for Legionella Bacteria: Regular inspections and water testing are essential to detect the presence of Legionella bacteria in a commercial water heater system. Look for signs of biofilm buildup, sediment accumulation, and any fluctuations in water temperature that could create an ideal environment for bacterial growth.
Flushing and Sediment Removal: Flushing the water heater tank and removing any accumulated sediment can help prevent the formation of biofilm, which can harbor Legionella bacteria. This maintenance task should be performed at least annually, or more frequently if the water supply has high mineral content.
Anode Rod Replacement: The anode rod in a storage tank water heater helps prevent corrosion and extend the lifespan of the tank. Over time, the anode rod can become depleted, allowing the tank to corrode and increasing the risk of Legionella growth. Replacing the anode rod according to the manufacturer’s recommendations is crucial.
Plumbing Techniques
Pipe Material Selection: The choice of pipe material can significantly impact the risk of Legionella growth in a plumbing system. Pipes with a smooth interior surface, such as those made from chlorinated polyvinyl chloride (CPVC) or copper, are less likely to promote biofilm formation compared to rougher materials like galvanized steel or cast iron.
Leak Detection and Repair: Identifying and repairing any leaks in the plumbing system is essential for maintaining water quality and preventing stagnation, which can lead to Legionella proliferation. Regular inspections and proactive maintenance can help detect and address leaks before they become a larger problem.
Insulation Strategies: Properly insulating hot water pipes can help maintain the desired water temperature throughout the system, reducing the risk of Legionella growth. Insulation also helps improve energy efficiency, which can be an added benefit.
Installation Methods
Sizing and Capacity Considerations: When installing a new water heater, it’s crucial to select a unit that is properly sized for the building’s hot water demand. Oversizing a water heater can lead to stagnation and increased risk of Legionella, while undersizing can result in insufficient hot water and potential temperature fluctuations.
Venting and Exhaust Requirements: Proper venting and exhaust systems are essential for safe and efficient operation of water heaters, especially in commercial applications. double-check that that the water heater installation complies with all local plumbing and building codes to mitigate the risk of Legionella and other potential hazards.
Electrical and Gas Connections: Proper electrical and gas connections are critical for the safe and effective operation of a water heater. Improper installations can lead to safety issues and may compromise the ability to maintain the necessary water temperature to inhibit Legionella growth.
Regulatory Compliance
Local Plumbing Codes: double-check that that the water heater installation and maintenance practices comply with all relevant local plumbing codes, which may include specific requirements for Legionella prevention and control.
ASHRAE Standard 188: The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) has developed Standard 188, which provides guidance on the prevention of Legionellosis associated with building water systems. Adherence to this standard can help mitigate the risk of Legionella in commercial water heater systems.
OSHA Legionella Guidelines: The Occupational Safety and Health Administration (OSHA) has published guidelines for the control of Legionella in workplace water systems. These guidelines can be valuable resources for commercial building owners and facility managers in developing Legionella risk management strategies.
Water Quality Factors
Hardness and Scale Formation: Hard water can lead to the buildup of mineral deposits, or scale, within the water heater and plumbing system. This scale can provide a breeding ground for Legionella bacteria and make it more difficult to maintain the necessary water temperature.
Corrosion and Chemical Treatments: Corrosion within the water heater or plumbing system can also contribute to Legionella growth by creating areas for biofilm to develop. Proper water treatment, such as the use of corrosion inhibitors or disinfectants, can help mitigate this risk.
Monitoring and Testing: Regularly monitoring the water quality and performing periodic testing for Legionella can help identify any issues early on, allowing for prompt corrective action to be taken.
Energy Efficiency Measures
Upgrading to High-Efficiency Models: Replacing older, less efficient water heaters with high-efficiency models can not only save energy and reduce operating costs but also help maintain the necessary water temperature to inhibit Legionella growth.
Improving Insulation and Circulation: Enhancing the insulation around the water heater and hot water pipes, as well as improving the circulation of hot water throughout the system, can help maintain the desired water temperature and reduce the risk of Legionella proliferation.
Incorporating Renewable Energy Sources: Utilizing renewable energy sources, such as solar power, can provide a more sustainable and potentially more reliable source of hot water, reducing the reliance on traditional energy sources that may be more prone to temperature fluctuations.
Legionella Risk Management
Temperature and Disinfection Controls: Maintaining the water temperature within the optimal range (above 140°F) is crucial for inhibiting Legionella growth. Supplementary disinfection methods, such as the use of chlorine or UV light, can also help control Legionella in the water system.
Maintenance and Monitoring Protocols: Developing and strictly adhering to a comprehensive maintenance and monitoring program is essential for identifying and addressing Legionella risks in a commercial water heater system. This may include regular inspections, water testing, and preventive maintenance tasks.
Emergency Response Planning: Preparing an emergency response plan in the event of a Legionella outbreak can help mitigate the impact and double-check that a swift and effective containment of the issue. This plan should outline the steps to be taken, the roles and responsibilities of key personnel, and the communication protocols with relevant authorities and building occupants.
By addressing the potential risks of Legionella in commercial storage tank water heater systems, building owners and facility managers can proactively protect the health and safety of their occupants while also ensuring the efficient and reliable operation of their plumbing infrastructure. For more information and guidance on water heater systems and plumbing solutions, visit https://waterheaterpick.com/.
Tip: Flush your water heater tank at least once per year
