Occurrence of Legionella in Groundwater

BACKGROUND: Legionella spp. in groundwater sources have been reported to be the cause of waterborne infections, specifically Legionnaire’s Disease and Pontiac Fever. Legionellae are known to be ubiquitous in surface waters, but much less is known about their occurrence in groundwater, which is the source of potable water for millions in North America. Federal drinking water regulations may not eliminate the threat of Legionella exposure from groundwater-derived drinking water. The primary reason is because current regulations focus on fecal contamination. Presently, there is no evidence that demonstrates an association between fecal contamination and Legionella.