Flint water continues to heal, meets EPA standards

More than two years after the Flint water crisis began, the water system in the Michigan city now meets the U.S. Environmental Protection Agency’s (EPA) Lead and Copper Rule, said Virginia Tech College of Engineering Professor Marc Edwards at a Friday news conference.

Additionally, levels of Legionella and associated disease incidence have steadily improved.

“Even though Flint is meeting the Lead and Copper Rule, residents should still strongly consider strategies to reduce lead exposure, including use of filters or bottled water,” said Edwards, University Distinguished Professor, during Friday’s news conference at Virginia Tech.

To continue to reduce levels of lead-in-water that are in normal range, the state of Michigan continues to provide water filters to Flint residents, free of charge, and encourages them to use filtered water for cooking and drinking.

“If you define the end of the water crisis as having water quality  parameters back in the range considered normal for other cities with old lead pipes, the answer is yes,” Edwards said when a reporter asked if the Flint crisis is over. “Obviously there is still a crisis of confidence among Flint residents that’s not going to be restored any time soon that’s beyond the reach of science to solve, but it can only be addressed by years of trustworthy behavior by government agencies who unfortunately lost that trust deservedly in the first place.”

In August 2017, Edwards and Lee-Anne Walters, Flint resident and hero-mom, led a citizen-coordinated water sampling effort, the fifth major lead sampling event coordinated by the Flint Water Study team. With funding from Virginia Tech, members of the 45-person team tested 138 of the original homes tested in August 2015, when the city-wide lead contamination was first revealed.

Min Tang, a civil and environmental engineering post-doctoral member of the team, explained that the 90 percentile lead level meets EPA criteria, based on collected first draw samples and publicly available data identifying service line materials published by the University of Michigan.

The 90 percentile lead level that meets EPA approved criteria shows, at first draw, a lead level of 9.8 parts per billion, below the 15 ppb federal action level. The result is consistent with official data collected by Michigan in May 2017, which reported a 90 percentile lead level of 6 ppb. The differences could be explained as the result of warmer water due to time of year and other small differences in the study approach.

The team back-calculated that during the height of the Flint water crisis in August 2015, the 90 percentile lead level found in the first draw was 31 ppb, based on an acceptable EPA high-risk sampling pool.  On that basis, the first draw lead in worst case homes has decreased by 68 percent.

Second draw and flushed water lead samples in the Flint citizen testing are also 70 to 80 percent lower than those collected by the team in August 2015, at the height of the water crisis. The water is now clearer and contains less iron, presumably due to less corrosive water and the corrosion control flowing through the water system. Only 1 to 2 percent of the samples collected in August 2015 had undetectable iron, in contrast to 44 to 55 percent of the samples collected in August 2017.

“Last year we predicted that the water system would continue to improve, as long good as corrosion control continues,” said Edwards, the Charles P. Lunsford Professor of Civil and Environmental Engineering in the College of Engineering at Virginia Tech. “The data seem to be consistent with that hypothesis.”

Additionally, William Rhoades, a civil and environmental engineering post-doctoral member of the team, concluded that levels of Legionella and incidences of Legionnaires’ disease support data by the Genesee County Health Department indicating that levels have dropped back to those that were present before the Flint water crisis. Findings show Flint has low or comparable risk of the bacteria in comparison to other regions of the U.S.

Edwards said Friday that cities around the country will continue to grapple with the issue of lead in water due to aging pipe infrastructure.

“We all owe Flint a huge debt of gratitude for exposing this problem,” he said.


In August 2015, Edwards’ team was alerted to the water crisis by Walters, who was concerned when her children’s health started to decline. After their sampling revealed very high levels in Walters’ home, Edwards’ team drove to Flint and collected extensive water quality and bacteria samples from homes, water mains, and hot water systems. Testing showed very low levels of chlorine disinfectant and high levels of bacteria.

On their spring break in March 2016, a team of civil and environmental engineering students from the Virginia Tech College of Engineering worked alongside residents led by Walters to collect water samples for a second round of lead and iron testing. The primary goal was to see how lead levels in Flint had changed since the city reconnected to Detroit’s water source, Lake Huron, and appropriate corrosion control added to the system.

During the second testing round, the team was able to re-sample 174 of the original 269 homes tested in August 2015. While those tests reflected improvement in the water, residents were urged to continue to use water filters and drink from bottled water.

The team also hypothesized that the lack of corrosion control and use of river water would trigger an outbreak of Legionnaires’ disease in FlintLegionella bacteria, which can cause a type of lung infection leading to pneumonia otherwise known as Legionnaires’ disease, survives in soil and water and can sometimes multiply in water systems, including hot tubs, air conditioners, and hot water heaters. Data from the team’s work has recently been reported in Environmental Science and Technology Letters and Environmental Science and Technology.

In summer 2016, two engineering graduate students led a 15-person team in the third round of testing, funded by the state of Michigan, working to examine the water quality in residential water heaters. Members of the Virginia Tech team tested water samples from water heaters in 30 Flint homes to evaluate the levels of Legionella before and after cleaning. Levels of detected Legionella were relatively low.

fourth round of lead testing was conducted in November 2016.

The Flint Water Study team also completed testing on the amounts of chloroform, total trihalomethanes, and disinfection byproducts present in Flint’s water. Testing earlier this year showed that Flint’s water, with Lake Huron as a source water and purchased from Detroit, meets all federal standards for chloroform, disinfection by-products, and total trihalomethanes, as described in a recent article by Susan Richardson, professor of chemistry and biochemistry at the University of South Carolina.

Edwards, a University Distinguished Professor at Virginia Tech, is a leading expert in safe drinking water and the deterioration of the water delivery infrastructure in America’s largest cities. He serves on Michigan Gov. Rick Snyder’s advisory group and has testified multiple times before Congress about the Flint water crisis and infrastructure issue.

Edwards and Flint pediatrician Mona Hanna-Attisha were honored in the 2016 TIME 100, Time magazine’s annual list of the most influential people in the world, for their work in Flint.