WASHINGTON (AP) — The Environmental Protection Agency’s inspector general says the Obama administration has failed to study as legally required the impact of requiring ethanol in gasoline.

The IG says the government also failed to investigate whether new regulations intended to address one problem actually make other problems worse.

The audit published Thursday confirms an Associated Press investigation in November 2013. The AP said the administration never conducted studies to determine whether air and water quality benefits from adding corn-based ethanol to gasoline. Such reports to Congress were required every three years under a 2007 law.

The AP investigation described ethanol as more damaging to the environment than the government predicted. Farmers who rushed to find new places to plant corn wiped out millions of acres of conservation land and polluted water supplies.