Court-ordered mediation in a federal lawsuit challenging the $650 million deepening of the Savannah River shipping channel resumes this week.

Attorneys for both sides meet behind closed doors in federal court in Charleston again Wednesday.

Environmental groups in South Carolina and Georgia have sued, saying the deepening will dredge toxic cadmium from the river floor and dump it on the South Carolina side of the river. The groups say the U.S. Army Corps of Engineers needs a South Carolina pollution permit for the work.

The Georgia Ports Authority wants the channel deepened to handle larger container ships that will routinely be calling when the Panama Canal expansion is open in two years. The Savannah project would deepen the channel from 42 feet to 47 feet.

Tags: politics, Savannah River, harbor deepening, mediation