Legionnaires’ Disease in Flint Tap Water

Eric Roy, Ph.D. 

A new report was released which confirmed that an outbreak of Legionnaires' disease in Flint, Michigan that killed 12 people and sickened at least 87 during 2014 and 2015 was likely caused by low chlorine levels in the municipal water system. It's another example of Flint's broader water crisis that resulted from widespread incompetence and fraud. We will add to this article as more questions come in.

What Is Legionnaires' Disease?

Legionnaires is a pneumonia, caused the bacterium Legionella pneumophila. Legionella pneumophila grows in water, and can enter the lungs through tiny water droplets. If a person doesn't have a robust immune system, they can become very sick, or even die.

Where Is Legionella Found?

According to Marc Edwards (A professor at Virginia Tech), Legionella is found in about 25 percent of all water samples collected nationally. It's a common bacterium, but it's usually kept under control in municipal water.

How Is Legionella Typically Controlled In Municipal Tap Water

In properly treated municipal water, Legionella is kept under control by chlorine-based disinfectants, so the bacterium cannot reach dangerous levels. In Flint, it appears that not enough chlorine was added to the water to leave enough residual chlorine to keep the bacterium under control, which is what caused the Legionnaires' outbreak in Flint.

Is Flint Still At Risk Of Legionnaires Disease?

According to Edwards, chlorine in Flint's water is now at the correct level, so the likelihood of Legionnaires' disease popping back up is minimal. It is our opinion at Hydroviv that concerned Flint residents should take every piece of advice issued by Dr. Edwards. If he says that there is enough chlorine, there is enough chlorine.