The Rev. David Bullock on Thursday holds a bottle of Flint water outside of the Romney Building, home to Gov. Rick Snyder’s office in Lansing. (Jake May/The Flint Journal-MLive.com/AP)

President Obama on Saturday signed an emergency declaration for the state of Michigan, clearing the way for federal aid to help resolve the water crisis in Flint.

For more than a year, parents there have voiced simmering concerns that a decision to change the city’s water source in 2014 resulted in the slow poisoning of their children. After initial their reluctance to admit a problem, local officials began changing their tone this fall.

On Oct. 1, county officials declared a state of emergency. The mayor followed suit in mid-December, followed by the governor earlier this month. On Thursday, he asked for Obama’s help.

“The state has responded, but the response needs far exceed the state’s capability,” Gov. Rick Snyder (R) said in a letter to the president, according to the Associated Press.

[This is how toxic Flint’s water really is]

Obama’s decision to issue the emergency declaration on Saturday frees up the Department of Homeland Security and the Federal Emergency Management Agency to coordinate relief efforts, help with emergency measures “and to lessen or avert the threat of a catastrophe in Genesee County,” according to a White House announcement.

Federal aid will come in the form of water, water filters, filter cartridges, test kits and other items over, at most, 90 days. The announcement did not contain an estimate for how much the aid will cost.

The problem can be traced back to April 2014, when the city switched its water source from Detroit to the Flint River to save money. Residents immediately complained about the smell and taste of the water. That summer, several boil-water advisories were issued. In October, a General Motors plant stopped using the water, which it claimed was rusting parts.

[A timeline of the water crisis in Flint, Michigan]

The problems continued throughout 2015. In October, Snyder announced state aid — and later approved legislation — to switch the city’s water source back to Detroit. On Tuesday, he activated the state’s National Guard to help distribute water and filters. On Wednesday, state health officials reported an increase in Legionnaires’ disease cases over the past two years in the county that includes Flint. On Thursday, he formally asked Obama to issue a disaster declaration and provide millions of dollars in aid.

Read more:

In Flint, bad tap water runs politically deep

In Flint, Mich., there’s so much lead in children’s blood that a state of emergency is declared

Flint, Mich., has 10 fatal cases of Legionnaires’ disease; unclear if linked to water