The North Carolina Dept. of Transportation is proceeding with a complex replacement of the Herbert C. Bonner Bridge on the Outer Banks, despite a new lawsuit that claims the project violates the National Environmental Policy Act.

PCL Civil Constructors Inc. and HDR Engineering Inc. of the Carolinas submitted the apparent winning bid of $215,777,000 for the design-build project that NCDOT estimated would cost approximately $241.6 million.

Replacing the deteriorating 2.7-mile, 260-span prestressed-concrete girder structure across Oregon Inlet has long been a top priority. It is the only highway link to Hatteras Island, one of the state's most popular tourist destinations and home to approximately 4,000 year-round residents.

Once NCDOT verifies the bid, PCL/HDR will develop a design for the new bridge, which will be built next to the existing structure. The four-year construction could begin as early as 2012, with a $10,000-a-day penalty for missing the still-to-be-determined target completion date.

But it faces a lawsuit filed last month in the U.S. District Court for the Eastern District of North Carolina, northern division. The Southern Environmental Law Center (SELC), on behalf of the National Wildlife Refuge Association and Defenders of Wildlife, contends that NCDOT and the Federal Highway Administration are legally bound to find a feasible strategy to not only replace the bridge but also to address frequent washout and erosion problems on an adjoining 12-mile stretch of state Route 12 within the Pea Island National Wildlife Refuge.

“The reality is that Highway 12 will continue to wash out with every major storm and can't remain in its current location,” said Defenders of Wildlife staff attorney Adam Kron in a statement issued by the organization.

NCDOT counters that the lawsuit's issues have been thoroughly assessed. The agency says it issued seven different impact analyses over the past two decades and spent $16.6 million to review all reasonable alternatives.

A specific strategy for maintaining Route 12 will be developed based on NCDOT's ongoing monitoring of it and the adjacent coastline. No time line for determining such a plan has been announced, however.

The SELC lawsuit is the latest in a 30-year series of clashes that have pitted environmentalists, who see Route 12 as a threat to fragile coast ecosystems, against local residents, who want a new structure to preserve a strongly tourist-based economy.