Repairs to the Interstate 526 span over the Wando River are needed because of “scour” affecting the foundation of three main supports, the state Department of Transportation said Thursday.

“SCDOT’s Bridge Maintenance Office has been monitoring continued bridge foundation scour at the bridges,” the DOT said.

“Due to an increase in scouring of the foundation at three pier locations of the east and westbound-lane bridges, the department has moved to perform scour repairs in order to protect the foundations.”

Scour is the removal of material around bridge supports caused by currents, according to the Federal Highway Administration.

The repairs are estimated to cost $1.5 million and will be funded as part of the previously approved 2012-2013 Federal Aid Bridge Replacement and Rehabilition Program.

When the work will start, how long it will last and whether it will affect traffic flow was not immediately available from the DOT.

Comments on the bridge work are being accepted through Oct. 11 by the DOT because an amendment to the Statewide Transportation Improvement Program is required for the repairs to happen. They may be submitted online at the DOT website, scdot.org.