Hamilton Kent Blog

How did lead get into Flint's drinking water?

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Photo credit: Jake May | (Jake May |

People across the country are zeroing-in on Flint, Michigan, asking “What went wrong?”

Corroded pipes have been leaking lead into homes and schools—and into drinking water—for over a year now. Concerned parents sit with their children at the doctor’s office as high lead counts are found in their blood test results—resulting in the declaration of a public health emergency and the need for ongoing monitoring for developmental damage done.

Mayor Elect Karen Weaver called for Flint to be named a National Disaster Area. Meanwhile, City officials point fingers at each other as local activists uncover false reports from the past year of testing for lead in the water.

The EPA and Michigan Auditor General Doug Ringler will now audit the Michigan drinking water program as a result of the crisis, which came about after the City terminated their service with the Detroit Water and Sewerage Department (DWSD) in 2014 in anticipation of switching to the Karegnodi Water Authority (KWA). The City had switched to water taken from the Flint River as an interim source, while they waited for the KWA water to arrive, but is now back on the DWSD—though residents are still at risk of high levels of lead.

So what went wrong inside Flint’s pipes?

The City’s pipe system was built for a much larger, more prosperous Flint—which has had a diminishing population in the wake of auto-industry factory closures. The pipe network has deteriorated along with the population, with water often stagnating and becoming discolored in the pipes.

Even before lead was on residents’ radars, they were boiling their water—first for high levels of fecal coliform bacteria in their water, and then elevated levels of trihalomethanes (THM) that resulted from high chlorine levels put into the water to mitigate the coliform bacteria.

Meanwhile, inside the pipes, Flint’s river water wasn’t being treated with any chemicals designed to control corrosion. The Michigan Department of Environmental Quality (MDEQ) decided against corrosion control after allegedly accidentally applying the rules for a much smaller city than Flint to the water system. As a result, lead began leeching out of a biofilm inside the pipes and into the water system from the highly corrosive river water. The biofilm is a coating created by phosphates added to the water.

The MDEQ was actually adding lime to the water as corrosion control, which ended up making the problem worse, and as a result, children are now being tested for lead poisoning at their schools.

Our clean water is a precious resource, and residents shouldn’t have to wait until aging pipes start to leak or becomes infiltrated with dangerous contaminants due to cost-cutting or neglect.

If you’re in a position to do so, advocate for or invest in new infrastructure. If not, we suggest writing to your area’s elected officials and remind them how important it is to get water infrastructure right.

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