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faucetWater quality researchers at Michigan Engineering are concerned about several long-term aspects of the Flint drinking water crisis and they’re keeping close tabs on the unfolding situation.

Faculty members in the Department of Civil and Environmental Engineering expressed worry over the extended use of certain household water filters, Flint’s future drinking water quality, and the broad impacts of the crisis on the city’s residents, economy and environment.

Flint’s drinking water was contaminated with lead after the city switched sources from Lake Huron to the Flint River as a way to save money in 2014. High levels of the toxin have since been found in the city’s children. In addition, experts believe that an outbreak of the bacterial infection Legionnaires’ disease – which killed 10 – is connected to the switch.

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Flint Water Filter Warning



Water quality researchers at Michigan Engineering are concerned about several long-term aspects of the Flint drinking water crisis and they're keeping close tabs on the unfolding situation.

Water quality researchers at Michigan Engineering are concerned about several long-term aspects of the Flint drinking water crisis and they're keeping close tabs on the unfolding situation.

Legionnaires’ link

“The link between the increased lead levels and the outbreaks of Legionnaires’ disease is indirect, but both are related to the switch in source water,” said Krista Wigginton, an assistant professor of civil and environmental engineering.

Several factors likely contributed to the Legionnaires’ outbreaks, the researchers say. There could have been lower levels of chlorine in the water due to increased chlorine demand from the higher levels of pollutants that were in the water after the switch. Other circumstances include higher summer temperatures, increased availability of nutrients such as carbon, nitrogen and phosphorus, increased concentrations of metals such as iron linked to corrosion, and greater exposure to aerosols in summer through air conditioner use.  

Water filter questions 

Terri Olson, an associate professor of civil and environmental engineering, studies how point-of-use water filters, which are installed on home taps, perform over the long term. Flint residents have received activated carbon filters to remove lead.

Olson has found that such filters—while effective at removing metals—can encourage the growth of microbes and possibly pathogens. That could pose problems for people with compromised immune systems.

In addition, she is concerned about how long the filters will be effective. Manufacturers recommend replacing the filters every 100 gallons (or about every two months) but that might not be an ideal time frame given the state of the water being filtered in Flint.

"These filters are very important as a short-term solution for households with high lead levels in their water," she said. "However, there is a need to confirm the safety of this strategy over time for a broader range of water quality parameters, not just lead.”

Closer monitoring needed

Aside from filters, the situation in Flint will need to be monitored for a long time, says Lut Raskin, the Altarum/ERIM Russell O'Neal Professor of Environmental Engineering.

“With regards to the future of the Flint crisis, we are particularly worried about the long-term impacts on microbial and chemical water quality,” Raskin said. “The interplay of low levels of residual disinfectants such as chlorine in the water distribution system and home plumbing and increased nutrient and metal availability will make it necessary to monitor the Flint water system in greater detail than typically required by regulations to avoid further public health impacts.”

She cautions that regulators will need to keep an even closer eye through the summer months, due to seasonal effects.

‘Why we have water laws’

The events in the city of roughly 100,000 will reverberate in many ways, other researchers point out.

“This case with Flint is egregious, in terms of violating good water quality engineering practice norms, trust and common sense,” said Nancy Love, a licensed professional engineer and professor of civil and environmental engineering who previously worked at Virginia Tech with the researchers who brought the current crisis to light.

“This case will be an example of why we have water quality and treatment laws for years,” 

More than a financial issue

For Glen Daigger, a professor of engineering practice at U-M and president and founder of water engineering firm One Water Solutions, the crisis drives home the fundamental importance of clean drinking water.

“A focus only on: ‘Where can we get water at the lowest cost?’ neglects the broad impacts of water on a community,” Daigger said. “Water is much more than just a financial issue. The positive impacts of good water management significantly exceed the cost. These impacts include on human health, but also positive impacts on the economy and the environment. It was Benjamin Franklin who commented that no one knows the worth of water until the well runs dry.”

The researchers have formed an interdisciplinary team with colleagues in microbiology, public health, and social sciences to develop a case study that could be used to educate future water quality engineers. And they’re also taking steps to provide technical information to water quality professionals across the state.

About Michigan Engineering: The University of Michigan College of Engineering is one of the top engineering schools in the country. Eight academic departments are ranked in the nation's top 10 -- some twice for different programs. Its research budget is one of the largest of any public university. Its faculty and students are making a difference at the frontiers of fields as diverse as nanotechnology, sustainability, healthcare, national security and robotics. They are involved in spacecraft missions across the solar system, and have developed partnerships with automotive industry leaders to transform transportation. Its entrepreneurial culture encourages faculty and students alike to move their innovations beyond the laboratory and into the real world to benefit society. Its alumni base of more than 75,000 spans the globe.