The Stepney Fire Department in Monroe was also on the scene, wrestling with the cleanup Monday afternoon.
Judd Road was closed between North Street in Easton and Hattertown Road in Monroe due to an accident and subsequent fuel oil spill, police said.
The road is expected to be closed for about 48 hours while crews clean up the area, Easton police said.
"Cleanup efforts should take several days," Monroe police said in a Facebook post. "Seek alternate routes."
The truck left the roadway and struck a tree, causing a rupture in the 2,500-gallon tank, firefighters said. Units from the fire department and the Connecticut Department of Energy and Environmental Protection (DEEP) were working to mitigate damage from the spill and clean it up.
"A large amount of oil spilled from the truck involved," Monroe police said.
No through traffic is allowed in the area, but all residents and emergency vehicles will have access to the residences in the area.
The Easton Board of Education is working with the Dattco Bus Co. to continue uninterrupted student pickup and drop-off at bus stops.
Any questions regarding bus routes should be directed to the Easton Board of Education 203-261-2513.
For all other information, call Easton Police Dispatch at 203-268-4111