How the Flint River got so toxic

Factories and people have been dumping sewage, chemicals, and road salt in the Flint River for more than a century

The Flint water crisis did not begin on April 25th, 2014, when the city switched its water supply from Detroit’s system, tapping Lake Huron to its own on the Flint River. That tragic mistake was the culmination of a much longer ongoing disaster, one caused by greed, politics, incompetence, and selective amnesia. The known consequences include lead poisoning, skin rashes, and carcinogens in the water. The total health consequences may not be known for years. Much has and will be written about that decision and its aftermath. Less has been written about how the Flint River became so polluted in the first place. Flint’s water crisis begins with the pollution of the Flint River, which has been going on for well over a century.

"It would be a mistake to conclude that Flint’s predicament is simply the result of government mismanagement,"  says Andrew Highsmith, author of Demolition Means Progress: Flint, Michigan, And The Fate Of The American Metropolis. "It’s also the product of a variety of much larger structural problems that are much more difficult to address." Besides economic factors, this includes a long history of environmental disasters and political dysfunction, much of it centered around the Flint River. None of these factors are unique to Flint; they’re at work in underfunded towns across the United States, the legacy of multiple industries from automobiles and chemicals to coal and agriculture.

This short history of pollution of the Flint River is gathered from multiple interviews and news sources, including over 400 historical documents from The Flint Journal, the City of Flint, the Flint Public Library, Flint’s Sloan Museum, the Environmental Protection Agency, the US Department of the Interior, and various Michigan state agencies.


Flint dam (Kris Runstrom)

The more polluted a water source is, the more processing required to make the water safe to drink. Most of the contaminants now in Flint’s drinking water were introduced during or after processing. For all drinking water, the first concern is bacteria, which can cause diseases like hepatitis, Legionnaire’s disease, and other illnesses. Because Flint’s river water had high levels of bacteria, it was treated with additional chlorine. Chlorine reacts with organic material in the water to produce carcinogenic byproducts such as trihalomethanes; it also makes water more acidic, which corrodes pipes. Federal law mandates adding anti-corrosive agents to drinking water in large cities;  this standard water treatment practice was not followed. Finally, stagnation anywhere along the line raises the likelihood of bacteria and makes the water less safe to drink.

Immediately after switching to the Flint River, Flint’s drinking water spiked in bacteria and trihalomethane readings. A Flint-area outbreak of Legionnaire’s disease also coincided with the switch, causing at least 10 deaths. The acidic water corroded the old lead pipes; along with other heavy metals, lead seeped into the drinking supply where it caused widespread lead poisoning. Lead poisoning is the most widespread and serious health problem associated with Flint’s drinking water; children with prolonged exposure to lead experience a range of developmental problems that are incurable. Once pipes are corroded, even clean, properly treated water continues to carry lead and other contaminants through the tap. This is why aid organizations are still distributing bottled water and water filters, even though the city has stopped using water from the Flint River.

the way flint mishandled water treatment is the primary cause of the water crisis

The way Flint mishandled water treatment is the primary cause of the water crisis. There is also the political question of officials’ responsibility for the crisis and their failure to respond after problems with the water became clear. But the original problem is that Flint’s river water is much more difficult to treat than water from Lake Huron, the city’s water source from 1974 to 2014. Flint’s water-treatment staff were not able to successfully make Flint River water safe to drink. Whether this is because they were undertrained, understaffed, or simply made a decision not to invest scarce resources into treating a temporary source of water — and who exactly made those decisions — is still unclear.

Why did Flint’s river pose so many problems? Before processing, the water itself is polluted from four sources: natural biological waste; treated industrial and human waste; untreated waste intentionally or accidentally dumped into the river; and contaminants washed into the river by rain or snow. The river is also warmer than Lake Huron, and its flow is less constant, particularly in the summer. All of this raises levels of bacteria and organic matter and introduces a wide range of other potential contaminants, whether natural or human-made.

In fact, while the Flint River had been improving thanks to the new regulations, the departure of heavy industry, and local cleanup efforts, it had long been known as an exceptionally polluted river. Until very recently, it had been repeatedly ruled out as a primary source for the city’s drinking water. It is hard to imagine why anyone familiar with the river’s history would ever decide to use it even as a temporary water source. But they did.


Undated photo of the No.11 Factory at the Buick Automobile Plant (Wystan / Flickr)

For most of its history, Flint (like other cities) didn’t worry about the pollution of its river. Contaminants certainly ended up in the city’s drinking supply. Industrial waste was introduced into the Flint River with the first lumber mills in the 1830s. After lumber came the paper mills, and chemical processing. As the forests around Flint were gradually cleared, the city switched from lumber and paper to carriages and finally automobiles. Between 1900 and 1930, Flint had its first boom, reaching a population of 150,000. The city had been drawing its drinking and industrial water from the Flint River since 1893, and discharging its untreated waste downstream.

In the 1930s, the fish began to disappear — first in the Flint River, then in the Shiawassee and Saginaw Bay. In 1934, a Genessee County conservation officer named Ivan Kester sent seven fish on ice to the University of Michigan’s newly formed Institute for Fisheries Research with a remarkable letter:


Enclosed you will find some fish and a sample of water taken from the Flint River at Flushing. There are thousands of fish dying in this river, and I am under the impression that Copper-Cyanide is the cause of these fish dying. Will you kindly check the water and fish I am sending you, and send me a report of your findings. Also mail a carbon copy of your reply to Mr. Adams, Pollution Division, Department of Conservation, Lansing, Mich.

The institute determined that pollution had lowered oxygen levels in the river, suffocating the fish.

"In the 1940s, there’s a lot of talk about pollution in the river," said Jeremy Dimick, curator of collections at Flint’s Sloan Museum. "There are calls for reform, but nothing behind them." (Oral accounts later cited in newspaper articles say oil on the Flint River caught fire at least two different times in the 1930s, but these stories aren’t reflected in the written record otherwise.) The once-plentiful stocks of walleye in the Flint River completely collapsed by the 1940s, due to polluted water poisoning incubating eggs.

After the war, Flint was booming again. Between 1945 and 1956, per capita water use grew from 56 to 81 gallons per day, while the city’s population had grown to nearly 200,000 people. A 1955 report stated that the Flint River would be unable to support the city’s industrial and residential needs. New regulations forced GM and other businesses to treat and dilute their waste with city water before releasing it into the river. The medium-sized river couldn’t provide enough water for a population expected to continue to grow until the end of the century.

Cleanliness and health were afterthoughts

In 1960, the Michigan Water Resources Commission gave Flint three years to "abate unlawful pollution of the Flint River." Primary polluters included the factories, paper and packaging companies, the meatpacking industry, various landfills, and the city’s wastewater treatment plant. When Flint switched to water processed by Detroit in 1967, the main motivation was to properly treat municipal and industrial waste and secure enough water for a growing population; cleanliness and health were afterthoughts. GM executives lead the push to switch to Detroit’s water system, hoping to save money and secure enough water for their needs. They and other city leaders "were most worried about the capacity of the river, especially [during] the summer: whether it could provide enough drinking water, enough water for industrial uses, but then enough water to dilute the waste as well," said Dimick. "It’s really to strive for more more capacity and more stability."

Switching to a new water source didn’t fix the Flint River. Studies through the rest of the decade found "poor water quality caused by numerous sources," including treated and untreated waste. After the passage of the Clean Water Act in 1972, a 1974 study of the Flint River showed improvement upstream of the city but significant toxins downstream. Raw sewage discharges from Flint’s wastewater plant raised fecal coliform bacteria; phenol from GM plants and ammonia from the wastewater plants contributed toxic materials. These chemicals cause skin rashes, cardiovascular and gastrointestinal diseases, and other health problems when ingested.

Heavy use of fertilizers in rural areas upstream of the city also polluted the river. A 1975 EPA study of the Holloway Reservoir upstream showed that phosphates from fertilizers and detergents had stimulated algae growth. Unchecked, the algae made the water’s oxygen levels collapse, turning it cloudy and brown.

Official landfills (like one in Richfield Township, now bankrupt, and a toxic cleanup site) and unofficial ones (like one on Bray Road, only cleaned up in 2014 so the city could dump its own wastewater sludge there) all polluted the grounds and groundwater. A 1996 story in the Flint Journal listed 81 closed dumps and landfills in the Flint area at various stages of cleanup, showing different levels of groundwater contamination. Some were monitored; many were not.

Road salt on the city's bridges may be one reason poorly-treated flint river water was so corrosive to flint's pipes

Road salt on the city’s bridges raised the river’s chlorine levels, making the water more corrosive. This has continued into the present and may have been one reason poorly-treated Flint River water was so damaging to metal pipes.

In 1977, a crack in the main water pipe from Lake Huron caused the city to temporarily switch to Flint River water and local filtration. Residents then reported a poor taste. Later reports indicate that it took "10 times the amount of chemicals to treat Flint River water than Lake Huron."

Between 1986 and 1988, high levels of coliform bacteria were intermittently found in Flint’s drinking water. Flint and Detroit blamed each other; the source of the infection was never found.


Holloway dam on the Flint River (Tony Faiola).

General Motors did its part to pollute the Flint River watershed, too. In the 1980s, nearly all of GM’s Flint plants were either in noncompliance or flagged for potential noncompliance with EPA regulations. Facing rising labor and cleanup costs — as well as a need for facilities that would meet new technological and environmental standards — GM closed its existing plants in Flint one by one. After multiple environmental assessments and cleanups, the buildings at Chevy In the Hole, GM’s flagship factory on the Flint River, were razed in 2004. In 2009, GM sold the site to the city of Flint for $1. Contaminants left behind include heavy metals like arsenic, mercury, and lead, toxic solvents, volatile organic compounds (VOCs), and polynuclear aromatics (PNAs) including petroleum compounds. The environmental profile at GM’s other former factories in Flint, like Buick City and Flint West, both EPA-funded cleanup sites, is similar.

It is difficult to precisely determine whether chemicals from Flint’s old factory sites made their way into the river. If they did, and from there made their way into Flint’s drinking supply, they could cause a wide range of problems, from lead poisoning to cancer. The terms of GM’s federally assisted bankruptcy and subsequent settlements with the EPA mean that neither GM, nor the city of Flint, nor the federal government is responsible for health problems associated with any of the former factory sites.

A spokesperson for General Motors declined to comment on industrial connections with the Flint River but gave the following statement:

From logging to industry and agriculture to recreation, the Flint River has served an important role in the growth and evolution of the Flint area. General Motors and its employees recognize the importance of the river and have worked actively to restore and preserve this natural resource. Through our involvement with the Flint River Watershed Coalition, GM employees actively participate in school programs, educating children about water quality. Inside our plants, our employees are active participants in our recycling efforts, which have helped several of the Flint-area sites to reach landfill-free status.

While environmental regulations kept companies from dumping waste into the river directly, illegal and accidental dumping were rampant. In 1990, a furniture salesman was convicted of dumping entire drums of methylene chloride, toluene and xylene, lead and other chemicals onto his property on the banks of the river. Sixty-five gallons of toxic sludge were found; 527,000 cubic yards of contaminated soil were removed. Lewis Street and Riverside Drive in east Flint, just south of the water plant, were known for years as prime spots for dumping furniture and garbage along the river, as well as high crime rates. There are dozens of stories like this.

Over two days, 22 million gallons of raw human, industrial, residential and commercial waste poured into the river

One of the most significant pollution events in Flint’s water history occurred in 1999. A subcontractor digging a trench to lay new fiberoptic cable near the Flint River opened a 6-inch-wide, 5-foot-long gash in an unmarked 72-inch pipe running from the city’s sewers to the Flint Waste Water Treatment Plant in Flint Township. Sewage filled a pond in a nearby golf course until the pump to the crushed pipe was shut down, diverting the untreated water directly into the Flint River.

Over two days, 22 million gallons of raw human, industrial, residential, and commercial waste poured into the river. On the second night, downstream in Mt. Morris Township, Karen Winchester saw hundreds of dead fish floating down the river past her property — catfish, carp, and bluegill, 3 to 20 inches long, all belly-up. For 14 months, health officials prohibited swimming, fishing, or direct contact with the river.

All of this was happening in the middle of Flint’s negotiations to extend its then 32-year-old contract for water from Detroit. The city was under pressure from the state to prove that it could treat drinkable water from the Flint River in an emergency.

"As far as we know, no [community] uses the flint river for a drinking water source."

Over the next year, bacteria levels continued to rise, fall, and rise again, suggesting ongoing pollution. In June 2000, the Michigan legislature passed a law requiring municipal and county authorities to report any sewage spill to the Department of Environmental Quality. It uncovered dozens more spills: as part of an amnesty program, nine communities in the Flint area reported 90 illegal sewage overflows over the preceding five years. Heavy rains, power outages, and accidents at plants or along sewage lines repeatedly dumped waste into the river. Flint itself declined to disclose any spills it hadn’t already reported. Communities began doing house-to-house checks looking for illegal hookups dumping into the sewer system or the river. Many were never found.

Despite the new law, the city continued to discharge untreated and partially treated sewage into the river during heavy rains, snowmelts, and power outages, including an 8-million-gallon spill in March 2006 and a 18.1-million-gallon spill in September 2008. The city’s takeover by state-appointed emergency managers did nothing to change the basic limitations of the river and the city and region’s ability to treat its own waste. It happened over and over again.

After each spill, many of Flint’s leaders repeated a version of the caveat James Helmstetter, the county’s director of environmental health, tacked onto his warning to residents after the 1999 spill.

"As far as we know, no [community] uses the Flint River for a drinking water source," he said.


Undated photo of the Blue Ribbon Carriage Factory in Flint (Wystan/Flickr)

In April 2014, when the city returned to local water, many officials and residents were hopeful that the legacy of the river’s pollution was behind them. They looked at what they could see — lower water costs, aesthetic improvement of the riverbank, the possibility of local control — and ignored what they couldn’t. The river, the city, and the people were all mistreated for years. The lead pipes and shoddy water treatment built on a century of pollution and neglect. They compounded and concentrated an ongoing human-made environmental disaster, with few analogies or precedents.

There are even calls to abandon Flint and resettle its citizens, at least temporarily, while its water infrastructure is replaced — or instead of paying to replace it. The entire city, once one of the most prosperous in the country, could become a brownfield.

"Governor Snyder called Flint his Katrina," a legislative aide to one of Flint’s representatives told me. "But it’s really more like a Chernobyl."