In finalizing new rule that will give it new authority to regulate pollution in streams, lakes, and rivers, the Environmental Protection Agency has a message for its critics: Bring it on.

Wednesday, EPA and U.S. Army Corps of Engineers announced it was going ahead with one of the Obama administration's more controversial environmental regulation proposals—the so-called Waters of the United States rule. The new rule, using authority to reduce pollution in waterways under the 1972 Clean Water Act, says that federal agencies have regulatory power over streams and wetlands that flow into downstream water sources, which EPA says will ensure that the government can restrict upstream pollutants.