In Flint, experts are warning that one potential solution to the city’s lead-tainted tap water has some serious potential downsides.
Whole house filters cleanse water of impurities and chemicals. Groups have been promoting their use in Flint to screen out lead. A company gave a presentation to the city council just a few days ago.
But experts say the filters have a downside.
Dr. Mona Hanna Attisha helped raised the alarm about lead in Flint’s tap water. She says ‘whole-house’ filters don’t screen out lead that leaches from pipes and filters inside the home.
“You want a point of use filter. So the water flows through your entire distribution system … where your house can have lead in different parts of the plumbing fixtures…and finally gets cleared at that point,” says Dr. Mona Hanna Attisha.
She points out the state is giving filters away for free, while the whole house filters cost hundreds to thousands of dollars.
Another concern involves bacteria.
Whole house water filters screen out chlorine. Many Flint residents complain of high levels of chlorine which affects the taste of the filtered water and make bathing feel more like showering in water from a swimming pool.
But the presence of disinfectants like chlorine helps kill bacteria. Not just in city pipes, but also in private homes.
Experts warn filtering out chlorine as it enters a home creates the possibility that harmful bacteria, like Legionella which causes Legionnaires Disease, could be an unwelcome side effect of whole house filters.
Virginia Tech’s Marc Edwards was another expert who helped sound the alarm about lead in Flint’s drinking water.
He understands why some Flint residents, tired of using bottled water for everything from drinking to bathing, might see whole house filters as a solution.
“No one is advising you to stop,” says Edwards, “But we want to be informed that there is a potential downside ... there’s limits to the protection [a whole house filter] offers.”
It’s expected to take several more years before Flint’s tap water will be safe to drink unfiltered.