Which two actions are most effective in minimizing Legionella risk associated with crossover lines?

Minimizing Legionella risk associated with crossover lines is critical for maintaining safe plumbing systems. The most effective action is installing a valve and drain at both ends of the crossover lines, effectively controlling the water that flows through them. By providing a means to isolate sections of the plumbing, you can manage and prevent stagnant water, which is a key factor in Legionella growth.

Avoiding crossover lines altogether is also beneficial because these lines can create conditions conducive to water stagnation and temperature fluctuations, further increasing the risk of Legionella proliferation. The presence of these valves and drains allows for better maintenance and management of water quality.

While the other strategies contribute to risk reduction, they may not provide the same degree of control or effectiveness. For example, flushing continuously and keeping sections dry can be helpful, but they require constant monitoring and may not be practical in all situations. Using high-temperature water can indeed kill Legionella, but maintaining that temperature consistently across a plumbing system can be challenging. Regular inspection and replacing old lines are useful practices, but they address issues reactively rather than preventing conditions that allow Legionella to thrive initially. Thus, proactive measures such as installing valves and drains provide a more robust approach to risk management for crossover lines.