The Flint water crisis is a public health crisis that started in 2014 after the drinking water for the city of Flint, Michigan was contaminated with lead and possibly Legionella bacteria.[2] In April 2014, during a budget crisis, Flint changed its water source from treated Detroit Water and Sewerage Department water (sourced from Lake Huron and the Detroit River) to the Flint River. Residents complained about the taste, smell, and appearance of the water. Officials failed to apply corrosion inhibitors to the water, which resulted in lead from aging pipes leaching into the water supply, exposing around 100,000 residents to elevated lead levels.[6] A pair of scientific studies confirmed that lead contamination was present in the water supply.[7][8] The city switched back to the Detroit water system on October 16, 2015.[9] It later signed a 30-year contract with the new Great Lakes Water Authority (GLWA) on November 22, 2017.[10]