Caledon OPP are investigating a spill in a stormwater pond near Coleraine Drive and George Bolton Parkway in Bolton.
The site has been secured, and the spill is currently contained within the pond.
The cause and substance of the spill have not yet been confirmed.
Residents are being advised to avoid the area, authorities say more information will be shared as the investigation progresses.
Drivers in the area should expect delays near Coleraine Drive and George Bolton Parkway, as it’s been reduced to one-lane traffic.