Flint residents knew there was a serious problem with their water when it came out of the tap brown and foul-smelling after the city of Flint changed its source from Lake Huron to the Flint River two years ago. They didn’t know, however, that lead levels were so high that the Environmental Protection Agency could classify it as hazardous waste. It took Michigan Republican Gov. Rick Snyder and the Michigan Department of Environmental Quality more than 17 months to acknowledge the problem. As a result, tens of thousands of Flint residents have been—and continue to be—poisoned.
The names of the people who made the decisions behind the poisoning are known. Snyder set the wheels in motion with a scheme that sacrificed the health of the people of Flint on the altar of austerity. In 2011, he ended public oversight by appointing his own man—an “emergency manager”—to cut costs and run the city. Flint went through a series of four emergency managers in as many years. When the extent of poisoning was known, Snyder did nothing. He failed to warn people against drinking the water and he failed to provide a safe alternative.
It’s infuriating. But anger is not action. What can we do to prevent the next municipal drinking water disaster? It is already here, flowing into the water glasses of millions of Americans. Chicago, Philadelphia and hundreds of other cities with old pipes have a lead problem. And that’s just the start of the municipal water pollution crisis. In most of the country, once-clean drinking water sources are now profoundly polluted—by treated and untreated sewage, by chemical-intensive agriculture, by waste from confined animal feeding operations and by industrial discharges. Even in Flint, the story begins not with lead pipes but with failed attempts to “treat” the source of the city water supply: the open sewer that is the Flint River.
Pipes and fixtures can be replaced, but all of the chemical contaminants in our drinking water cannot be removed, no matter how advanced the technology. The solution is to prevent them from getting there in the first place.
Flint: The whole story
Just as there’s no mystery about the toxic combination of racism and neoliberalism that caused the Flint water crisis, there is no mystery about the chemistry that caused the lead to leach from Flint’s pipes. Lead rarely occurs naturally in water. It enters our drinking supply either from industrial or wastewater-treatment discharges or, more commonly, because it leaches out of lead pipes, solders and brass fixtures in the distribution network.
Some conditions make the lead leach faster. This is what happened in Flint when, under the control of an emergency manager, the city switched its water source from Lake Huron to the Flint River and then added chemicals that made the situation worse.
It’s not that the Flint River has elevated levels of lead in it. The trouble—besides the high bacteria levels and untold number of harmful chemicals—is that its water is corrosive. Depending on the rainfall conditions at the time of measurement, as much as half of the river is made up of wastewater from the city’s sewage treatment plant. Before it’s released into the river, the wastewater is treated with chlorine.
Pulling drinking water from a river of treated sewage is not unusual. A 1980 EPA study (the most recent one conducted) indicated that more than 24 major public water utilities got their water from rivers in which sewage treatment plant discharges constituted over 50 percent of the flow during low-flow conditions. In 1985, there were about 6,700 municipal wastewater treatment plants. Since then, an additional 10,000 have been built, which collectively disgorge 33,657 million gallons per day of effluent into rivers, lakes, streams and oceans. To give you an idea of how that compares to public water use, 23,800 million gallons per day are used for drinking water, landscaping, toilets, showers and sinks, and another 18,200 million gallons per day go to industry and commercial businesses.
The Flint sewage treatment plant, located on the banks of the Flint River, keeps 20,000 pounds of chlorine on hand. The wastewater leaving the plant—which averages 32 million gallons per day, but can be as high as 75 million gallons per day—is chlorinated before being dumped into the Flint River.
Disinfecting wastewater with chlorine is a common practice in wastewater treatment that helps the effluent stay below regulatory levels for coliforms— an indicator of fecal contamination. (This does not mean the Flint River is without coliform bacteria. Tests published by the city of Flint show high coliform levels in the river. Sewage treatment overflows, leaks and illegal sewer pipes dumping into the river could be the cause of this.)
Adding chlorine to water is an effective way to dramatically reduce pathogenic bacteria. But chlorine solves one problem only to create another: It helps create the chemical conditions that free up lead from pipes, solders and fixtures. The city could have lessened the corrosion by adding a corrosion inhibitor, such as orthophosphate, to the water—a measure that would have cost just $100 a day—but chose not to.
However, the city had another problem that couldn’t be so easily ignored. Chlorine mixed with water creates a class of chemicals called disinfection byproducts (DBPs). There is epidemiological evidence of a close relationship between DBPs and cancer. The EPA regulates just four of the more than 500 known DBPs, one of which, trihalomethanes (THMs), was already in the Flint River at concentrations in violation of EPA drinking water standards. The city needed to lower bacteria levels in its water, but couldn’t add more chlorine without raising concentrations of THMs, so it switched to chloramine (chlorine plus ammonia), which solves the problem of THMs but leaches lead even faster than chlorine. (Chloramine also creates its own DBPs, but these are not regulated.)
Chloramine’s highly corrosive effects are well-documented. In 2001, after a switch from chlorine to chloramine, tests showed Washington, D.C., water was leaching lead from the distribution system. Civil engineering professor Marc Edwards of Virginia Tech, an expert on water treatment, sounded the alarm. Just like the whistleblowers in Flint, the municipality and the EPA ignored him. It took two years for the D.C. water authority to notify the public about high lead levels in the water. Then the city began partial lead pipe replacement—a solution that has been shown to, counterproductively, “result in significantly elevated levels of lead in tap water … for weeks and months,” as EPA chemist Michael Schock told Environmental Health Perspectives in 2010. (Scientists are still trying to figure out why this happens.)
The D.C. case was widely publicized. But if the city of Flint was to continue using Flint River water, it had to address the immediate problem of the cancer-causing THMs, the chlorine byproducts. So the city made the switch from chlorine to chloramine.
Flint, like all cities in the United States with pipes over 30 years old, has lead in its distribution system. The same story of chloramine corrosion unfolded in Flint as it had in D.C. In summer 2015, Dr. Mona HannaAttisha, a Flint-based pediatrician, got a tip from a friend at the EPA that Flint might have a leaching problem, and began studying hospital blood samples. A paper she co-authored in the February 2016 issue of American Journal of Public Health showed that incidence of elevated blood lead levels in Flint children doubled, and in some neighborhoods nearly tripled, after the city began using water from the Flint River.