Inspector general reports over the past few years detailing employee misbehavior could serve as ammunition for EPA Administrator Scott Pruitt, who is seeking to eliminate 25 percent of the 15,000 employees at the agency.

Only 6.5 percent of EPA employees are "essential," according to the government's own calculations when it faced a shutdown in 2013. At the time, just 1,069 employees were deemed necessary to continue working during the 16 days the government closed.

The most notorious case of misconduct was the EPA official who earned $120,000 and performance bonuses after being caught watching pornography for up to six hours a day.