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Unsafe E. Coli Levels Found In Houston Floodwaters, Homes

E. coli and other contaminants ended up in homes after sewage treatment plants saw more water than they could handle during Hurricane Harvey. Once homes flood, they become hospitable environments for bacteria to multiply.

An aerial view of the flooding caused by Hurricane Harvey in Houston, Texas, Aug. 31, 2017. Hurricane Harvey formed in the Gulf of Mexico and made landfall in southeastern Texas, bringing record flooding and destruction to the region. U.S. military assets supported FEMA as well as state and local authorities in rescue and relief efforts.
An aerial view of the flooding caused by Hurricane Harvey in Houston on Aug. 31. Once homes flood, bacteria can multiply faster than in flooded areas outdoors.

Water in some flooded Houston homes is contaminated with bacteria, lead and other toxins, according to a New York Times report. The paper organized testing in two Houston neighborhoods with experts from Baylor Medical College and Rice University, along with the Houston health department.

One home was found to have 135 times the level of E. coli bacteria that is considered safe.

The contaminants ended up in homes after sewage treatment plants in Houston saw more water than they could handle during Hurricane Harvey.

Houston’s storm drainage and water treatment systems are supposed to be independent of one another, but an unprecedented amount of rainfall brought storm water into treatment plants.

“When we get very heavy rainfall and flooding, there is infiltration [of storm water] that occurs in these sewer lines,” Lauren Stadler, an assistant professor of of civil and environmental engineering at Rice University who took part in the Times‘ research, tells Houston Public Media. “That can basically overload our treatment plants.”

Because those treatment plants were overloaded, engineers had to rush incoming water through, skipping a step in the treatment process. The plants then emptied the partially treated water into Houston’s bayous. Those bayous flooded, letting contaminated water into people’s homes.

Once homes flood, Stadler says, they become good environments for bacteria to multiply. The warmth and stagnant water provided by a flooded structure, when combined with the nutrients from sewage, mean that bacteria can multiply faster inside homes than in flooded areas outdoors.

Stadler urges people not to make direct contact with floodwaters, if possible. She notes that while draining water will take most contaminants along with it, residents of flooded homes should have their houses disinfected after waters recede.

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