GRANTS PASS, Ore. (AP) — The U.S. Supreme Court will decide whether to switch gears on more than 30 years of regulating the muddy water running off logging roads into rivers.

At issue: Should the U.S. Environmental Protection Agency keep considering that muddy water the same as water running off a farm field, or start looking at it like a pipe coming out of a factory?

The case being heard Monday in Washington, D.C., originated from a small environmental group in Portland, the Northwest Environmental Defense Center. It sued the Oregon Department of Forestry over roads on the Tillamook State Forest that drain into salmon streams.