FLINT, Mich. (WOOD/AP) — Two state employees are accused of failing to treat Flint’s water and altering test results, leading to the lead problem that has permanently impacted the health of children in Flint.

Those employees — Stephen Busch and Michael Prysby of the Michigan Department of Environmental Quality — are now facing charges of misconduct in office, conspiracy to tamper with evidence and tampering with evidence.

Michigan Attorney General Bill Schuette announced Wednesday he filed a total of 13 felony charges and five misdemeanor charges against Prysby and Busch, as well as Flint employee Michael Glasgow.

Prysby is charged with four felonies and two misdemeanors. Schuette said Prysby altered water test results in Flint and tried to conceal it. He said Prysby also violated Michigan’s Safe Drinking Water Act by failing to treat Flint River water with corrosion control.

Busch is charged with three felonies and two misdemeanor charges. He’s also accused of manipulating water test results and tampering with evidence, as well as failing to treat Flint’s water to prevent the corrosion that led to the lead problem.

“They failed Michigan families; indeed, they failed us all,” Schuette said.

Glasgow is facing a felony charge of tampering with evidence and a misdemeanor charge of willful neglect of office. He was the plant’s laboratory and water quality supervisor during the water switch. He is now the city utilities administrator.

Glasgow previously said he planned to treat Flint’s drinking water with anti-corrosive chemicals after the city began tapping the source, but was overruled by Prysby, who was a district engineer with the Office of Drinking Water and Municipal Assistance at the time.

In a legislative hearing, Glasgow said Prysby told him a year of water testing was required before a decision could be made on whether corrosion controls were needed. Michigan’s DEQ has since acknowledged Prysby misinterpreted federal guidelines on preventing lead and copper pollution.

Corrosion control wasn’t incorporated into the Flint River water tapped by the city for 18 months. The mistake allowed lead to leach from aging pipes and fixtures and contaminate tap water that reached some homes, businesses and schools.>>PDF: Timeline of events in Flint

According to emails released by Gov. Snyder’s office, Glasgow messaged a DEQ official a few weeks before the switch, complaining that the process was moving too quickly and his staff needed more training. The plant had about 40 employees when he began working there in 2005, he said, but only 26 when it began treating and distributing Flint River water.

“If water is distributed from this plant in the next couple weeks, it will be against my direction,” Glasgow stated in an April 17, 2014 message. The city switched to the Flint River eight days later, the Associated Press reported.

Prysby transferred to the Water Resources Division’s Transportation and Flood Hazard Unit on March 28.

Busch and Prysby were formally arraigned later Wednesday afternoon. Busch pleaded not guilty, while Prysby stood mute to the charges for now.

Both were released on personal recognizance bonds and are expected back in court on May 4 for hearings. Defense attorneys and prosecutors said there are tens of thousands of documents they have to go through before those first hearings — so many that they were scheduled later than in a typical case to give them enough time.

Each felony charge carries a sentence of up to 4-5 years in prison, as well as thousands of dollars in fines.

“These charges are only the beginning, and there will be more to come, I guarantee you,” Schuette said.

24 Hour News 8 visited residences in DeWitt, Bath Township and Otisville, which is north of Flint, on Wednesday seeking comment from the three suspects, but no one answered the door at any of the homes.