The Environmental Protection Agency Friday proposed restrictions on a large copper-and-gold mine slated for a watershed in southwest Alaska that has pitted environmental groups against business regarding the EPA’s authority to veto such projects.

At issue for the Pebble Mine near Bristol Bay’s watershed is whether the EPA can veto a needed Clean Water Act permit. The proposal comes with a comment period that ends Sept. 19. If finalized, it could invite legal action from the mine’s backers on an issue that has attracted the attention of congressional Republicans.