New London — In a turnaround that city officials tout as a gamechanger for the underused waterfront, state environmental officials have signed off on establishment of a seasonal restaurant and bar on Custom House Pier.

The state Department of Energy and Environmental Protection has issued a five-year conditional license to the city for the restaurant, a reversal from its terse initial rejection of the idea last year.

With the permit in hand, the city is now poised to sign a revised lease with Frank Maratta for the opening of the Whaling City Dock, a restaurant and oyster bar. It is expected to open next spring.

Maratta, the owner of several successful waterfront restaurants, first pitched the idea of a restaurant built with modified 50-foot shipping containers last summer. He foresees a casual-fare restaurant with an open kitchen and barbeque smoker. Among other restaurants, Maratta developed Harbor Park in Middletown, Sunset Ribs in Waterford and the Pavilion in Old Lyme.

He said he was excited for the opportunity in New London and frankly surprised it hasn’t been tried in the past, calling New London a “gem.”

“There’s such a vibe down there. It’s just unbelievable,” Maratta said.

When he approached the city’s Port Authority with the idea, the proposal was widely praised as a way to boost the visibility of the city’s waterfront and bring in more people and boaters.

The City Council later approved a 10-year, $2,300-a-month lease, with options for additional years, with Restaurant Consultants Inc. Maratta is the president of the company.

DEEP dampened any expectations with a letter from its Land & Water Resources Division of the Bureau of Water Protection and Land Reuse. The letter discouraged any privatization of the Downtown Waterfront Park piers by any non-water-dependent structures such as a restaurant.

The indication was that a permit for such uses was simply not something allowed in Connecticut.

Mayor Michael Passero and Felix Reyes, the director of the city’s Office of Development and Planning, said Friday they have since worked out a solution through a collaboration with DEEP officials and the governor’s office.

Passero said most of the discussion surrounded what the term water-dependent use means, considering the fact that few if any boats use that stretch of the pier.

“We made it work,” Reyes said. “This creates a new destination, a spark, some life where there was none.”

The DEEP license has conditions that include the installation of ladders, bumpers and fenders along the perimeter of Custom House Pier for recreational boating. It also requires maintenance of a water taxi berthing area and floating dock at the south end of the pier.

Plans submitted to DEEP show a restaurant created from shipping containers with a covered dining areas and bar near the end of the pier. Maratta said he also has agreed to maintain the existing public bathrooms near the pier, which presently are closed to the public.

Passero said the permit is not exclusive to Maratta’s operation but said Maratta has made the investment and holds rights to the lease. The lease is expected to be revised because of the new conditions from DEEP.

Reyes gave credit to DEEP for finding a creative way to allow for a permit while protecting public use of the pier. The pier will remain open to the public while the restaurant is open. DEEP authorizes the restaurant to be open between April 15 and Oct. 15.

Maratta said he expects to have the infrastructure in place this fall in anticipation of an April opening.

g.smith@theday.com