BANGOR – With Eastern Maine Healthcare’s option to buy the Waterworks buildings set to expire at the end of the month, city officials here are pondering the future of the historic riverside complex.

“We’ve tried just about everything over there,” Rod McKay, the city’s director of economic and community development, said Wednesday. “But there’s no question we have to do something with it.”

That something, at this point, does not include renewing the hospital’s option to buy the property, McKay said, adding that EMH officials had not approached the city about a renewal.

The buildings, the oldest of which dates back to 1875, have sat vacant on the banks of the Penobscot River for more than 25 years. Since then, city officials have courted potential developers who have explored the costly possibility of renovating the structures.

In years past, developers have proposed everything from restaurants, time shares, and residential units to and hotels for the waterfront site.

The high cost of refurbishing the complex has stymied all of the restoration efforts thus far, most recently those of nearby Eastern Maine Medical Center.

The hospital had proposed moving its computer systems from the basement of the Riverside Inn to the Waterworks. However, as construction costs climbed to more than $4.5 million, hospital officials were forced to back off the plan, according to Norm Ledwin, president of Eastern Maine Healthcare.

“We would have had a hard time justifying the cost to our board or to the public either, I think,” Ledwin said Wednesday. “We’re still interested, but we would have to look for some alternative funding.”

The hospital’s development plans for the site would cost between $218 and $250 per square foot, McKay said. For comparison, EMH spent about $117 per square foot to refurbish the Westgate Mall, and the cost of building a new facility would be about $100 per square foot, McKay said.

“It’s been the problem every time we’ve tried to do something with that building,” McKay said of the high cost of remodeling.

The city had proposed a deal in which it would buy the hospital’s Sylvan Road property for about $1 million, which could be put toward the Waterworks renovation. As part of the deal, the city would have also widened State Street and installed a traffic signal at the site.

Despite the deal’s demise, McKay said the city has no intention of demolishing the boarded-up buildings, which are fraught with rotting floors and deep, open shafts that once housed the facility’s huge turbines.

“I’m not even considering that at this point,” he said of the possibility of leveling the brick structures.

The complex is a historic landmark under the city’s Historic Preservation Ordinance. In 1999, Maine Preservation, a statewide nonprofit, listed the structures as among the state’s most endangered historic properties.

In addition to exploring admittedly remote funding possibilities for the EMH proposal, city officials are also actively pursuing a plan for the federal restoration group, Coastal America, to restore the building.

The group, which undertakes coastal restoration projects for the cost of materials, has expressed interest, McKay said. In return, the buildings must be accessible to the public, he said.