The Environmental Protection Agency didn't live up to a promise to turn over documents about the Flint, Mich., water crisis Friday, Sen. David Vitter said.

The Louisiana Republican hit the EPA for not responding to his request for documents and communications related to the agency's response to the crisis in Flint, which has left 100,000 people unable to drink their tap water.

Vitter said that on Tuesday, EPA Administrator Gina McCarthy promised to turn over documents and communications in "a day or two." Vitter first made the request, with Senate Environment and Public Works Committee Chairman Jim Inhofe in February. As of Friday, the request went unfulfilled.

"They set their own deadline and failed, even after having months to respond. Leadership starts at the top, and Administrator McCarthy's empty promises expose more of the systemic accountability problems within the EPA," Vitter said. "Rest assured, I will continue to push for answers on EPA's inaction before and during the Flint water crisis."

McCarthy's emails about Flint have been made public, including her warning that the crisis could get "very big" in September 2015.

In April 2014, a state emergency manager appointed by Michigan Gov. Rick Snyder signed off on a symbolic vote from the Flint City Council to change the city's water source. The move aimed to cut costs by requiring the city to take its water from the Flint River instead of the Detroit Water and Sewerage Department while a new pipeline was built to connect the city to Lake Huron.

The Flint River water, however, was so acidic that it caused the lead pipes bringing water from the city's cast iron mains into homes to corrode. Lead leached off the pipes and into the drinking water throughout the city.

The state and the federal government have declared a state of emergency, and Flint residents are not able to drink the water coming out of their taps.

Two Michigan Department of Environmental Quality employees and one city employee were charged Wednesday with crimes related to the crisis.

Mike Prysby, Stephen Busch and Mike Glasgow were charged with multiple felonies related to the crisis, according to court documents. Busch was the department's district supervisor for Flint's water system, Prysby is an engineer at the agency and Glasgow is Flint's water quality supervisor.

Busch and Prysby are charged with two counts each of tampering with evidence and misconduct in office. They also face a charge of violating the Safe Water Drinking Act, court records show.

Glasgow faces one charge of tampering with evidence and one charge of being a public officer and willfully neglecting his duty.