Michigan's top environmental officer was by turns cooperative and confrontational with the U.S. Environmental Protection Agency on Friday, pledging to work together to ensure the safety of Flint's drinking water but challenging the legality and scope of some federal demands.

In a letter to U.S. Environmental Protection Agency Administrator Gina McCarthy, Michigan Department of Environmental Quality Director Keith Creagh wrote that the state "is committed to working" with her department and Flint to deal with the city's lead-contamination problem. But he said the state has "legal and factual concerns" with an EPA order a day earlier taking state and city officials to task for their efforts so far and requiring them to take specific actions.

Creagh said Michigan "has complied with every recent demand" of the EPA and that Thursday's federal order "does not reference the tens of millions of dollars expended by ... the state for water filters, drinking water, testing and medical services."

"The order demands that the state take certain actions, but fails to note that many of those actions ... have already been taken," Creagh, who recently replaced an official who resigned over the water crisis, wrote in his required response to the EPA order.

Flint's water became contaminated with lead when the city switched from the Detroit municipal system and began drawing from the Flint River in April 2014 to save the financially struggling city money. The water was not properly treated to keep lead from pipes from leaching into the supply. Some children's blood has tested positive for lead, a potent neurotoxin linked to learning disabilities, lower IQ and behavioral problems.

Creagh wrote that state officials don't know whether it's legal for the EPA to order Michigan to take such actions. Among other requirements, the EPA said the city should: submit plans for ensuring that Flint's water has adequate treatment, including corrosion controls; ensure city personnel are qualified to operate the water system in a way that meets federal quality standards; and create a website where the public can get information.

Earlier Friday, The Flint Water Advisory Task Force issued recommendations to Snyder aimed at restoring reliable drinking water in Flint. The advisory group said its recommendations are more detailed and comprehensive than what the EPA ordered, and Snyder said officials would "move as quickly as possible to determine the best way to achieve the results."

Separately, Snyder announced the suspensions of two employees of the state Department of Environmental Quality in connection with regulatory failures that led to the crisis.

The panel's recommendations included working with the EPA staff on a comprehensive lead-sampling program and seeking help from the federal Centers for Disease Control and Prevention in assessing an outbreak of Legionnaires' disease and its cause.

"To help address both the technical issues facing Flint, as well as the public-trust issues, we believe it is imperative to have the right people and organizations involved," task force Co-Chairman Chris Kolb said. "Until the public trust starts to build, this crisis will continue."

Flint's public health emergency led to local, state and federal emergency declarations, the last of which could bring up to $5 million in direct funding to the city. The federal government denied a request for additional aid through a disaster declaration, saying the program is designed for natural disasters and therefore not appropriate for the city's drinking water crisis. The government announced Friday that it had denied an appeal of that decision by Snyder.

The unnamed DEQ employees who were suspended Friday pending investigations work in the agency's drinking water division, state spokesman Kurt Weiss said.

The agency's director and communications director resigned last month.

"Some DEQ actions lacked common sense, and that resulted in this terrible tragedy in Flint," Snyder said.

While much of the blame over the crisis has been directed at Snyder and state officials, particularly the Department of Environmental Quality, some have faulted the EPA's Region 5 office for not acting more forcefully.

The EPA's order to state and city officials came the same day that the agency announced that Susan Hedman, head of the agency's regional office in Chicago whose jurisdiction includes Michigan, was stepping down Feb. 1.