Which water system would likely provide the least benefit for routine Legionella sampling?

Irrigation systems are typically not associated with the conditions that promote the growth of Legionella bacteria, which thrive in warm water environments (between 77°F and 113°F) and can be aerosolized, creating a risk for exposure. These systems often use water that is at or near ambient temperatures and are designed for non-potable uses, making them less likely to harbor this specific bacterium.

In contrast, hot water systems are a primary concern because they can reach temperatures conducive to bacterial growth if they are not adequately maintained. Cold water systems also warrant monitoring, as stagnant water can lead to conditions that favor Legionella proliferation. Fire protection systems may include water storage in tanks or piping susceptible to temperature fluctuations and stagnation, also raising the concern for Legionella.

Overall, the irrigation system, given its operational conditions and intended use, is expected to yield the least benefit from routine Legionella sampling compared to the other systems.