What are the sources of legionella?

Legionella is ubiquitous in the environment and is found in hot and cold water taps, creeks, ponds, and surrounding soil. Potting soil has also been associated with cases of Legionellosis, though the mechanism is unknown. Legionella does not transmit from person to person. 

For water, the route of exposure is through aerosolization or inhalation. Exposure has been associated with hot water systems, air conditioning cooling towers, evaporative condensers, mist machines, decorative fountains, respiratory therapy devices, humidifiers, hot tubs, and whirlpool spas.

Show All Answers

1. What is legionella?
2. What are the sources of legionella?
3. What are the risks?
4. How does the City of Napa control and monitor for legionella in drinking water?
5. How can legionella be controlled in residential homes?
6. What are large building best practices for control of legionella?