CHARLESTON — Attorneys on both sides of a lawsuit over dredging the Savannah River shipping channel want a federal judge to rule in their favor quickly and without a trial.

Attorneys for the Savannah Riverkeeper, the U.S. Army Corps of Engineers and the Georgia Ports Authority filed motions late last week asking U.S. District Judge Richard Gergel to rule.

Environmentalists have sued, saying the corps needs a South Carolina pollution permit for the $650 million project because toxic cadmium will be dredged from the river and deposited in a spoils area on the South Carolina side of the river.

The Georgia Ports Authority wants the harbor channel deepened so the ports can handle larger container ships that will routinely be calling when the Panama Canal is expanded in 2014. The chief executive of the Panama Canal Authority speaks Tuesday at a trade conference on the Isle of Palms, S.C.

The lawsuit was brought by the Southern Environmental Law Center on behalf of the Savannah Riverkeeper, based in Augusta, Ga., as well as the South Carolina Coastal Conservation League and the South Carolina Wildlife Federation.

Attorneys for the Savannah Riverkeeper argue it is clear pollutants will be discharged into South Carolina and a permit is needed. It says Congress has directed to corps to comply with state pollution laws in such projects.

"The Corps seeks not to be a faithful steward of the environment in its position as implementer of this public works project, but instead seeks to ignore and avoid South Carolina's sovereign right to protect the integrity of the state's environment, ecosystem and natural resources," their motion said.

But the Corps of Engineers says it is in compliance with South Carolina law because the project has been approved with a federal Clean Water Act certification from the state Department of Health and Environmental Control.

Attorneys for the Georgia Ports Authority also argue South Carolina law does not require a separate Pollution Control Act permit for a project that has already received such certification.

The state of South Carolina, they argue "cannot discriminate against federal projects conducted by the Corps by imposing additional permitting requirements not applicable to the state itself or private individuals."

They note that of the $652 million price tag for the entire deepening, almost half will be spent on mitigation projects to protect the river environment and fish and wildlife.

The judge has appointed former U.S. Rep. John Spratt to mediate in the dispute. The judge has set a court hearing for November.