A section of Route 741 in Lancaster Township was closed for several hours Thursday after a tractor-trailer crashed into the Conestoga River bridge.
The truck hit the bridge at around 10:45 a.m., causing motor oil to spill into the river.
A hazardous-materials team responded to clean up the spill.
The driver was taken to a hospital for treatment of minor injuries.
Route 741, locally known as Millersville Road, has since reopened.