The Army Corps of Engineers denied a construction permit for
Alaska's Pebble Mine project to proceed in accordance with the
Clean Water Act (CWA).1 Excavation of Pebble Mine —
a sprawling depository of gold, copper, and molybdenum —
would discharge fill material and dredge into U.S. waterways.
The project's developers applied for a permit under the CWA,
requiring the Army Corps to assess the project's potential
impact on nearby bodies of water. When project-produced dredge and
fill threaten unavoidable adverse impacts on waterways, projects
may not proceed without appropriate mitigation measures.
In reviewing the Pebble Mine developer's plan, the Army
Corps weighed the project's cumulative environmental impact
against proposed mitigation efforts. It determined that the project
would "cause unavoidable adverse impacts to aquatic resources
which would result in Significant Degradation to aquatic
resources." Subsequently, the Army Corps denied the permit
because the
