LACEY, Wash. -- Morning traffic backed up seven miles into Lacey after a truck overturned on northbound I-5, blocking a lane near the Nisqually River bridge.

Transportation Department spokeswoman Lisa Murdock said the truck remains on the shoulder and traffic will have to be restricted after 8 p.m. Thursday for the wreckage to be removed.

The double-trailer semi-truck carried paint and pesticide, so the state Ecology Department also responded to the scene.

State patrol Lt. Sean Hartsock said it took longer than normal to move the wreck off the road because of the hazardous chemicals.

"We do have a water estuary behind us -- we don't want the spill to go in there," he said.

About 15 gallons of latex paint spilled on the shoulder after the 1:40 a.m. crash. None reached the nearby Nisqually River and no pesticide spilled.

The driver suffered only minor injuries.