The parties in a federal lawsuit challenging the deepening of the Savannah River shipping channel are inching closer to a resolution.

That was the message recently relayed in a letter released by Georgia Ports Authority, the Army Corps of Engineers, the Savannah River Maritime Commission and The Southeastern Environmental Law Center.

Late last year, U.S. District Court Judge Richard Mark Gergel ordered the sides to come together in mediation to find a compromise in the dispute about dredging the river that runs between South Carolina and Georgia.

Georgia wants to deepen the waterway to accommodate larger container ships at the Port of Savannah. Opponents in South Carolina said the project would harm the environment, and also put the Port of Charleston at a competitive disadvantage.

Environmental groups in both South Carolina and Georgia have sued, saying that deepening the shipping channel will dredge toxic cadmium from the river floor and dump it on the South Carolina side of the river. The groups contend the Army Corps needs a South Carolina pollution permit for the work.

The opposing sides met in two meetings, and another mediation session is tentatively scheduled for sometime later this month. Gergel ordered sides to not discuss specifics about the talks.

“However, the parties are authorized to make public the fact that progress has been made and settlement discussions are ongoing,” according to the letter.

Gergel’s order in November came days after the S.C. Supreme Court ruled the S.C. Department of Health and Environmental Control’s board violated state law in approving a water quality permit for the $650 million deepening of the river’s shipping channel.

The Supreme Court sided with environmentalists who sued, challenging the DHEC board’s approval of the permit needed to deepen the Savannah River.

The court agreed the state’s Savannah River Maritime Commission was charged with matters concerning the river, and threw out the permit approval decision. As a result, an earlier DHEC staff decision to deny the permit took effect.

The Supreme Court’s decision came days after the Army Corps of Engineers in Georgia announced its approval to deepen the river to 47 feet from 42 feet and plans to seek congressional approval of an exemption of South Carolina’s Clean Water Act certification. The Corps said it wanted to prevent “inappropriate delays” to the project because of the ongoing lawsuit.

Earlier that year, the Southern Environmental Law Center filed the federal complaint, arguing the project requires a South Carolina pollution control permit. Gergel said in his order that the Supreme Court rendered the pollution control permit moot.

The Port of Charleston is also pursuing a plan to deepen its shipping channel to 50 feet from 45 feet, to accommodate the massive container ships that will soon be able to pass through the Panama Canal, which is being expanded.