All sides involved in a lawsuit challenging a $35 million cruise ship terminal on the Charleston peninsula agree on one point: They want a federal judge to rule on the case to avert a costly trial.

Two preservation and environmental groups sued the Army Corps of Engineers for allowing the State Ports Authority to drive five pilings as part of the project at Union Pier Terminal.

Both sides spelled out their arguments for a favorable ruling from U.S. District Judge Richard M. Gergel in a flurry of documents filed Monday.

The case is one of several legal challenges to the SPA’s cruise business. The heated debate is pitting peninsular neighborhood associations and other groups against the local maritime industry and the city.

The tone grew sharper three years ago, after Carnival Cruise Lines moved its 2,056-passenger ship Fantasy to Union Pier, making Charleston a year-round cruise-passenger destination.

The city and SPA have said the industry is regulated properly and that pleasure ships will never be more than a niche operation.

Opposition groups want to clamp down on the big vessels, saying they’re damaging the Historic District by generating more tourists, vehicles and pollution.

The SPA is proposing to turn a vacant warehouse at the north end of Union Pier into a passenger terminal to replace its obsolete cruise facility near the end of Market Street. It’s seeking to have the lawsuit tossed.

Assistant U.S. Attorney John Douglas, who represents the Corps of Engineers, argued that the pile-driving permit the agency approved last year was proper. The work is maintenance on an existing structure, he said.

The SPA said the pilings would have minimal impact.

“The five piling clusters are being added to the thousands of pilings that presently support Union Pier,” the maritime agency says in a document this week.

Attorney Blan Holman, who represents the plaintiffs, said the work isn’t maintenance because the use of the empty cargo warehouse would change. He also said the project would have consequences beyond the waterfront.

“The record overwhelmingly demonstrates that construction of a new home terminal for 10-story high, 1,000-foot-long cruise ships in the heart of the best-preserved city in the United States has at least the potential for impacts on historic properties and the human environment,” Holman says in his written argument.

He also says the Army Corps did not consider other sites for the new cruise building in North Charleston, Mount Pleasant and at the SPA’s Columbus Street Terminal.

The Preservation Society of Charleston and the S.C. Coastal Conservation League filed the lawsuit last year. They are seeking to revoke the federal permit. They also want more studies and public review.

The case could go to trial in November if Gergel declines to make a ruling.

Contact John McDermott at 937-5572. The Associated Press contributed to this report.