LANSING, Mich. (AP) — Two Michigan environmental regulators implicated in the Flint water scandal pleaded no contest to a misdemeanor Wednesday in exchange for more serious charges being dropped, bringing to six the number of officials who have agreed to such deals.

Stephen Busch pleaded no contest to disturbing a public meeting, and Michael Prysby pleaded no contest to a count of violating Michigan’s Safe Drinking Water Act. They had been charged with felonies, but those charges and others were dismissed under the terms of their deals that also require them to testify against others, if needed.

A no contest plea is not an admission of guilt but is treated as such for sentencing purposes. Their sentencings are scheduled for Jan. 23.

The plea from Busch, a water supervisor in the state Department of Environmental Quality, relates to his failing to address concerns during an unruly January 2015 meeting in which Flint residents complained about the city’s discolored and smelly water after the April 2014 switch from a Detroit-area system to using the Flint River.

Busch, who had faced involuntary manslaughter and other felony charges, said in a Flint courtroom Wednesday that he had conversations with state Health and Human Services Director Nick Lyon about legionella bacteria before March 2015 — many months before Lyon and Gov. Rick Snyder publicly announced a deadly Legionnaires’ disease outbreak in the Flint area. Some experts have blamed the outbreak on the use of the river.

Lyon, a member of Snyder’s Cabinet, is the highest-ranking of the 15 state or local officials to be charged in relation to the water crisis .

The plea from Prysby, a DEQ water engineer, relates to the improper permitting of Flint’s water treatment plant during the switch.

Todd Flood, a special prosecutor hired by Michigan Attorney General Bill Schuette, put on the record parts of Prysby’s cooperation to date.