Sorry commuters. Just when you thought the end of the Route 518 bridge repair project was near and your commuting nightmare would finally be over, the project is stalled again.

The New Jersey Department of Transportation has stopped work on the Route 518 bridge between Rocky Hill Borough and Franklin Township because workers discovered a chemical in the ground and water near the project, a spokesman said Thursday.

Creosote, a wood treatment chemical, recently was found in the ground and water by the contractor near the project.

“This discovery required us to put a temporary stop-work order in place while we established an environmental plan,” NJDOT Spokesman Steve Shapiro told Planet Princeton Thursday.

Both the New Jersey Water Supply Authority and the D&R Canal State Park were notified of the situation, Shapiro said.

“NJDOT understands that this project is locally sensitive and we are working as quickly as possible to resolve the issue and complete the reconstruction of the bridge, but these types of unexpected environmental issues demand immediate attention to ensure the safety of the workers and the residents,” he said.

A revised timeline for the completion of the bridge project is not available yet. The bridge replacement work was scheduled to be done by the end of February after months of delays.

Work on the bridge spanning the Delaware & Raritan Canal began on July 6 and was scheduled to have been completed in about four weeks. Gov. Chris Christie froze work on all state-funded projects less than a week later. Residents held protests at the bridge on a daily basis starting in August. In September, the Somerset County Board of Chosen Freeholders announced that it was in talks with the DOT to offer stopgap funding for the project so that work could as negotiations to fund the state’s transportation fund continued. In October, the state legislature passed a bill that was signed by Governor Chris Christie increasing the state gasoline tax by 23 cents a gallon to fund the transportation fund.

Work on the bridge resumed at the end of November but was stopped last week. The closure of the bridge has been a major headache for commuters, more than doubling the driving time for many people. Area businesses have also suffered because of the closure and traffic.