AUGUSTA, Maine (AP) Maine lawmakers have unanimously endorsed a proposal to upgrade a 14-mile stretch of the Androscoggin River to a higher environmental classification in an acknowledgment of cleanup efforts.

Beth Ahearn from Maine Conservation Voters called the votes in the House and Senate “a fitting tribute” to the landmark Clean Water Act pushed through 50 years ago by U.S. Sen. Edmund Muskie, a Maine Democrat who grew up in Rumford, the Sun Journal reported.

It is likely that Democratic Gov. Janet Mills will sign the measure into law.

The Maine Board of Environmental Protection already endorsed the move for a portion of the river’s status to upgraded from the lowest category, Class C, to Class B from Lisbon Falls to Merrymeeting Bay.

Environmentalists are convinced they can make the case for upgrading a longer section of the river but that won’t happen this year.

Not everyone was supportive of the change. Some mills and businesses upstream fear stricter environmental standards could make it difficult for them to operate under certain conditions.