U.S. President Barack Obama signed an emergency declaration Saturday that clears the way for federal aid for Flint, Michigan, which is undergoing a drinking water crisis due to lead-contaminated water.

The White House also said the Federal Emergency Management Agency (FEMA) will co-ordinate all disaster relief efforts to "alleviate the hardship and suffering" of residents. FEMA has been authorized to provide water, filters, cartridges and other items for 90 days. Flint can get up to $5 million US in direct funding, though the state must match 25 per cent and more money can come through an act of Congress.

Michigan Governor Rick Snyder had asked the president to declare both an emergency and an expedited major disaster in Genesee County, saying needs "far exceed the state's capability," and added that emergency measures could cost $41 million.

Flint Water

Flint, Mich., native and filmmaker Michael Moore attended a rally outside city hall in Flint on Saturday, Jan. 16, 2016, accusing Gov. Rick Snyder of poisoning the city's water. (Jake May/The Flint Journal - MLive.com/Associated Press)

Snyder said Saturday that Obama denied the disaster declaration request based on the legal requirement that such relief is intended for natural events, fires, floods or explosions. Despite the legal limitation, the governor is considering an appeal to exhaust "every opportunity to provide resources" for residents, Snyder spokesman Dave Murray said.

Elevated lead levels in children

The tap water in Flint, population 99,000, became contaminated after the city switched from the Detroit water system to the Flint River while a pipeline to Lake Huron is under construction. The decision to use the river was made while a Snyder-appointed emergency manager was running the city government due to its financial problems. The corrosive water from the Flint River lacked adequate treatment and caused lead to leach from old pipes in homes and schools.

Flint returned to the Detroit system in October after elevated lead levels were discovered in children, and could tap into the new pipeline by summer. But officials remain concerned that old pipes could continue to leach lead, to which exposure can cause behaviour problems and learning disabilities in children as well as kidney ailments in adults.

MICHIGAN-WATER/

Michigan National Guard Staff Sergeant William Phillips, left, assists a Flint resident with bottled water at a fire station in Flint, Mich. on January 13, 2016. (Rebecca Cook/Reuters)

The National Guard has been distributing free water, filters and other supplies, and FEMA workers already were providing logistical and technical support.

Democratic U.S. Sen. Debbie Stabenow said she will push for long-term resources, and U.S. Rep. Dan Kildee, also a Democrat, said residents "deserve every resource available to make sure they have safe water and are able to recover from this terrible man-made disaster created by the state."

The U.S. Justice Department is helping the Environmental Protection Agency investigate the matter, and state Attorney General Bill Schuette has opened his own probe, which could focus on whether environmental laws were broken or if there was official misconduct.