Following a major water main break, how should a facility prioritize risk management regarding Legionella?

Evaluating the building’s occupancy history is a critical factor in prioritizing risk management regarding Legionella following a major water main break. This is because the occupancy history can provide insights into the potential for Legionella growth and transmission. For instance, areas that have been unoccupied for extended periods may pose a higher risk for Legionella proliferation due to stagnant water in plumbing systems. Understanding how many people have occupied the building, as well as the activities typically performed, helps in determining the risk exposure for susceptible individuals, such as those with compromised immune systems.

Maintaining a close watch on these occupancy patterns helps to inform mitigation strategies, such as flushing systems or adjusting maintenance protocols to reduce the risk of Legionella growth. This context shifts the focus from strictly environmental assessments—which may not account for variations in human interaction with the site's facilities—toward a more comprehensive understanding of how occupancy affects water quality issues.

Addressing risk through the lens of occupancy history allows for targeted interventions that can effectively mitigate the risk of Legionella exposure, prioritizing areas based on their usage and occupancy levels.