QUINCY — Washington Department of Transportation officials are not sure yet what the revised timeline will be on the construction of a roundabout at State Route 28 and White Trail Road. Department of Transportation officials discovered a mistake in the project after construction had started.

“We needed to remove a little bit of concrete,” Lauren Loebsack, communications manager for the WSDOT North Central Region, said Monday.

In a separate post on the WSDOT blog, Loebsack wrote that the concrete island at the center of the roundabout was installed in the wrong place.

“As it was initially built, the north-south line of the intersection with White Trail Road was too far to the west,” she wrote.

One of the options, she said Monday, was to leave the concrete island in place and rework the roadway, but WSDOT officials determined that redesigning the road wouldn’t have worked. Among other things it might’ve pushed the project outside the existing WSDOT right of way, she said.

“(The concrete island) was too far off the central line,” Loebsack said.

Reengineering also would’ve taken a lot of time, Loebsack wrote on the WSDOT blog.

“We determined the misalignment was too great for this kind of small adjustment. It creates enough offset that continuing with the current alignment would require several months of additional engineering and right-of-way work,” she wrote. “For the sake of completing the project in the shortest possible time for the needed results, we decided to remove what won’t work and rebuild the roundabout to the proper alignment.”

The contractor for the White Trail Road roundabout also is working on a roundabout at East Street and Highway 97/2 in Wenatchee. Department of Transportation officials also reviewed that project.

“We, unfortunately, confirmed a similar issue there,” Loebsack wrote. “We’re still working out how this happened.”

The mistake was discovered the first week of May, she said.

The concrete island had not been replaced as of last Thursday, May 11. Last Thursday construction crews were installing a concrete vault to accommodate fiber optic cables.

Loebsack said Monday the revised construction schedule is still to be determined.

“We’re not sure. We’re still working with the contractor,” she said.

State Route 28 is still open for eastbound and westbound traffic during the construction. It’s been reduced to one lane, which is controlled with a temporary traffic signal. White Trail Road is closed to north-south traffic across the intersection.

Grant County officials have established a detour from State Route 281 westbound, or SR 28 eastbound, along White Trail Road. The route uses Road 9 NW, Road V NW and Road 10 NW, which connect White Trail Road to SR 28 at the rest stop at the top of the ridge.

Cheryl Schweizer can be reached via email at education@columbiabasinherald.com.