FLINT, MI - Felony and misdemeanor charges have been issued against three state and city employees in connection to the city's water crisis.

Genesee District Court Judge Tracy Collier-Nix authorized charges, Wednesday, April 20, for Flint employee Michael Glasgow and Michigan Department of Environmental Quality employees Stephen Busch and Michael Prysby.

Glasgow is accused of tampering with evidence when he allegedly changed testing results to show there was less lead in city water than there actually was. He is also charged with willful neglect of office.

Prysby and Busch are charged with misconduct in office, conspiracy to tamper with evidence, tampering with evidence, a treatment violation of the Michigan Safe Drinking Water Act and a monitoring violation of the Safe Drinking Water.

None of the individuals charged in the case have been arraigned.

The three were not in court when the warrants were issued and no attorneys for the men were present.

All three men are facing felony charges. Glasgow faces up to four years in prison for the tampering charge, while Busch and Prysby each face up to five years in prison on the misconduct charges.

Schuette's office claims Prysby and Busch knowingly misled Environmental Protection Agency regulator Miguel Del Toral that the city was using proper corrosion control when they knew the city was not.

They are also accused of impeding the Genesee County Health Department's investigation into a Legionella outbreak that left 12 people dead and manipulating lead testing results to show the city's water is safe.

Prysby, then a district engineer with the the state's Office of Drinking Water and Municipal Assistance, allegedly told Glasgow that phosphate wasn't required when Flint switched to a local river for water in 2014, Glasgow said during testimony at a legislative hearing last month.

Busch, former DEQ district supervisor in the division, was suspended earlier this year pending an investigation tied to Flint water.

Busch's name appears on a number of documents that were penned as the Flint water crisis unfolded after the city began using the Flint River as its drinking water source in 2014.

Michigan Department of Environmental Quality employees Michael Prysby, left, and Stephen Busch address issues with the water quality on Wednesday evening, Jan. 21, 2015, at the Flint City Hall dome in downtown Flint. Sam Owens | MLive.com

Busch, with the Michigan Department of Environmental Quality's drinking water division, told other DEQ officials in a March 26, 2013, email that the use of the river could lead to multiple problems, including increased disinfectant by-products and microbials in the water, which could put the public's health at risk.

According to Busch's email, continuous use of the river could pose an increased microbial risk and risk of potentially cancer-causing disinfection by-products.

Glasgow said the city was struggling to collect the number of samples that were required following the city's switch to the Flint River as its water source in April 2014.

Water samples sent to state labs for testing in the first six months of this year were all marked as having come from homes with lead service lines, but actually almost always came from homes at less risk of lead leaching - houses with underground plumbing made of copper, galvanized steel or materials that could not be identified, according to the city's own documents given to The Journal through the Freedom of Information Act.

In this July 22, 2013 file photo, Michael Glasgow, laboratory water quality supervisor, tests water for bacteria and pH levels, among other tests, at the Flint, Mich., water plant. Jake May | MLive.com

Records of the material in individual service lines were not readily available or did not exist, Glasgow has said, leading the city to submit samples regardless of whether homes were at high risk of lead in water.

The U.S. Environmental Protection Agency requires that water sampling be done at "high-risk" locations whenever possible to better ensure that high levels of lead or copper are detected as soon as possible. Lead service lines are most likely to leach lead in water, and the American Water Works Association says cities like Flint should have been collecting 50 percent of samples from such high-risk homes.

That didn't happen in Flint, records show, even though the state and city have estimated that at least 15,000 homes in Flint have lead service lines.

Glasgow, the only certified plant operator at the water plant when it went into service, also sounded warnings that the city was not ready for the switch.

"I was reluctant before, but after looking at the monitoring schedule and our current staffing, I do not anticipate giving the OK to begin sending water out anytime soon," Glasgow's email says. "If water is distributed from this plant in the next couple weeks, it will be against my direction.

"I need time to adequately train additional staff and to update our monitoring plans before I will feel we are ready. I will reiterate this to management above me, but they seem to have their own agenda."

The charges come following an investigation by Attorney General Bill Schuette.

Schuette is scheduled to host a press conference today in Flint to make a "significant announcement" on his office's investigation. A spokeswoman for Schuette's office declined comment on specifics of the announcement.

However, a source with information on the case told MLive that the press conference will be used to announce the charges.

In early 2015, the city of Flint disregarded federal rules requiring it to seek out homes with lead plumbing for testing, potentially leading the city and state to underestimate for months the extent of lead leaching into the tap water at area homes.

City water officials filed certified documents with state regulators that claimed the city only tested tap water from homes where people were at the highest risk of lead poisoning.

Records obtained by The Flint Journal-MLive showed those claims were false and may have delayed efforts to fix the public health emergency here.

The city is in the national spotlight after elevated blood lead levels were discovered in some Flint children after the city changed its water source from Lake Huron water purchased from the Detroit water system to the Flint River in April 2014, a decision made while the city was run by a state-appointed emergency manager.

State regulators didn't require the river water be treated to make it less corrosive, causing lead from plumbing and pipes to leach into the water supply.

Though the city reconnected to the Detroit water system in October, officials say the city is still not meeting federal requirements for safe drinking water.

MLive Impact Team member Ron Fonger contributed to this report.