CANTON, Ohio (AP) — Ohio's environmental watchdog agency has raised the proposed penalty against a company building a high-pressure natural gas pipeline across the state after tests found diesel fuel in samples taken from the 2 million gallons of drilling mud that spilled into a wetland in April.

The Canton Repository reports (http://bit.ly/2qJ8WA1 ) that the Ohio Environmental Protection Agency on Thursday hiked the proposed penalty from $430,000 to $914,000 against Energy Transfer, the Dallas-based company building the $4.2 billion Rover pipeline project.

The state EPA also has ordered the c...