A decades-old practice of directional drilling in the Great Lakes is likely coming to an end.

The state Senate voted 28-5 Wednesday to ban oil drilling under the lakes.

Sen. Dianne Byrum, who has worked on the Great Lakes Task Force, said public testimony led her to support the ban.

“It was very clearly something that the residents were in favor of,” the Onondaga Democrat said.

Officials have argued extensively since July about the bill, which is sponsored by state Rep. Scott Shackleton, R-Sault Ste. Marie.

Until recently, ban supporters feared the progress would end at the desk of Gov. John Engler, who has expressed opposition.

But the support in the Senate and House, which voted 98-7, has convinced the governor to announce he “expects it to be law,” Engler spokesman Matt Resch said.

“It was pretty overwhelming support,” Resch said.

Much of the controversy over the bill arises from analysis that say drilling isn’t as environmentally harmful as once believed. And the history of the practice lent itself to the opposition’s case, said Brad Wurfel, Michigan Department of Natural Resources spokesman.

“There has not been a single environmental accident in the state of Michigan,” he said.

For the senators whose constituents were saying otherwise, however, the scientific evidence was hard to accept, state Sen. Valde Garcia said.

The St. Johns Republican, who voted against the bill, said the legislation is a bit too harsh without evidence backing it, even though it had public support.