Under current rules, most workers can't make overtime if they earn more than about $24,000 per year.
The U.S. Department of Labor is awarding grants to programs helping youth and adults re-entering society after incarceration.
The investigation is part of an initiative aimed at identifying labor violations in the Midwest's college towns.
Landree Mine in Greene County received a dozen violations.
Indiana unions added about 3,000 members in 2013, and the same number of nonmembers working in union shops.
The Indiana Occupational Safety and Health Administration has been cited for mishandling complaints and setting investigation quotas.
The Department of Labor's safety administration says 34 of the violations could have caused death or serious physical harm.
The agreement requires companies to provide fall protection and hazard identification training for all members by March 2014.
The Department of Labor is starting the effort because transportation incidents are the leading cause of Indiana workplace fatalities.
Officials say the state should be able to absorb the cuts because it is in good fiscal condition.