CHARLESTON — A mediation session is set for next month in a federal lawsuit opposing a passenger cruise terminal in Charleston, one of three challenges to the proposed $35 million project.

Court records show a mediator for the 4th Circuit Court of Appeals in Richmond plans to meet with attorneys on Jan. 7. Both the South Carolina State Ports Authority and the U.S. Army Corps of Engineers are appealing a decision by a federal judge tossing out a Corps’ permit for the project.

U.S. District Judge Richard Gergel, in a lawsuit brought by environmental, preservation and neighborhood groups, ruled in September that the Corps did not adequately review the project’s effects on the city’s historic district.

The lawsuit challenged a permit allowing additional pilings beneath a waterfront warehouse so the structure may be renovated for the terminal. Gergel ruled the impact of the terminal effects on the city should be considered, not simply the environmental impact of adding the pilings in the water.

A second legal challenge is in the state Administrative Law Court.

Terminal opponents say since the federal permit has been tossed out, a state Department of Health and Environmental Control permit allowing the pilings and a certification that the project complies with state coastal rules must also be invalidated.

They say a water quality review was encompassed by the federal permit but and now that it has been tossed out, the state must conduct its own review. Both the Ports Authority and DHEC oppose invalidating the permit. An administrative law judge has set a hearing for late next month.

A third case has the state Supreme Court mulling whether the city’s cruise industry is a public nuisance. The justices heard arguments last month and have not indicated when they might rule.

The debate about cruises has raged in historic Charleston for several years.

Terminal opponents say they are not against cruises, but want limits so they don’t overwhelm the city. Supporters say the city will only be a niche cruise market and the industry is being appropriately regulated.

Carnival Cruise Lines permanently based its 2,056-passenger liner Fantasy in Charleston more than three years ago, giving the city a year-round industry. Before that, ships made port calls, but none were based in Charleston.