The poisoning of the public water supply in Flint, Mich., has been a disaster in many ways unique to that city. A series of bad decisions, apparently meant to save money, fed dirty, improperly treated water from the Flint River through the city’s plumbing for more than a year. This corrosive flow leached lead from aging pipes, and now the children of Flint have ingested far more than enough to harm their mental and physical development.
One important link in Flint’s chain of errors, however, is a problem common to many American cities. It has to do with the way public water is tested for lead. Federal rules require that testing be done, but water utility officials are allowed to carry out their tests in ways that allow unsafe amounts of lead to go undetected.
The federal rule dates to 1991, when the Environmental Protection Agency limited the amount of lead in drinking water. If concentrations rise above 15 parts per billion in more than 10 percent of a city or water district’s taps, the utility has to either replace the service lines or improve the way they treat the water running through them.
This is because in many cities, especially in the Midwest and Northeast, the service lines that bring water into people’s houses — as opposed to the water mains that run under the street — are often made of lead. And as those lines age, or if the water running through them is improperly treated, drinking water can become hazardous.
In Flint, officials not only began to tap the polluted Flint River but, worse, stopped treating the water with anti-corrosive chemicals. Soon, the brown, foul-smelling water coming out of faucets was also dangerously contaminated with lead.
In theory, federal standards requiring regular lead testing should have caught this. But Flint, like many other American cities, used a water-testing technique that underestimated lead levels, by asking customers to “pre-flush” their taps before collecting a sample. This reduces the amount of lead in the sample.
The same and similar techniques — including asking customers to open the tap slowly, run only cold water or remove the aerator in the faucet — have been documented in cities around the country, including Philadelphia, Washington and Chicago. Utilities also sometimes concentrate sampling in neighborhoods known to have low lead levels, or count samples from homes that don’t have lead pipes. The EPA considers these techniques “against the intent of the monitoring protocol,” but so far has failed to ban them.
Allowing utilities decide how to administer their own lead tests gives them both opportunity and incentive to game the system. The stakes are enormous: According to one study, if the EPA required utilities to take water samples directly from service lines, the drinking water of as many as 96 million Americans would exceed the safety limit for lead levels.
The agency is now considering revising the 1991 regulations to tighten the protocols for lead testing. The rules should be stringent enough to ensure that all cities get an early warning when lead levels rise to the danger point.
