The Flint Water Crisis was a public health crisis and environmental disaster that began on April 25 of 2014. On this day, the city of Flint, Michigan, switched to using the Flint River as its main water source. The pipeline was not tested for toxins or treated for corrosion prior to becoming operational, and it started leaking contaminants into the city's drinking water. Approximately 140,000 residents were exposed to lead and other toxins such as trihalomethane, with lead levels above 15 ppb detected.

On October 1, 2015, the city issued an advisory that the water was not safe to drink, but the pipes were not fixed. Many residents had no choice but to continue using the contaminated water, which also leached into the ground and polluted nearby lakes, rivers, and streams. This crisis is ongoing. As of 2021, some residents continue to suffer adverse health effects caused by lead poisoning and some still do not have access to clean water.