CHEYENNE, Wyo. (AP) — Wyoming's top regulator of oil and gas development is quitting after he remarked that greed motivates people who assert that hydraulic fracturing contaminated their groundwater.

Gov. Matt Mead on Thursday announced the resignation of Tom Doll, supervisor of the Wyoming Oil and Gas Conservation Commission.

Doll's comments last week at a meeting of state oil and gas regulators in Vancouver, British Columbia, involved residents near Pavillion in central Wyoming. Mead distanced himself from the comments and Doll later apologized, saying the remarks were "inappropriate and inconsiderate."

The U.S. Environmental Protection Agency says fracking may have contaminated groundwater in the Pavillion area. Fracking improves the productivity of oil and gas wells by cracking open deposits with pressurized water and chemicals mixed with sand.

Doll didn't immediately return a phone message Thursday.