Firefighters responded to a mulch fire along I-95 in Orange on Thursday afternoon.
The fire was in the area of Marsh Hill Road near the West Haven town line, according to fire officials. Three mulch piles were burning at a construction site, they said.
Smoke from the fire was blowing over the highway, creating visibility problems for drivers.
Local fire officials called in forestry crews from the state Department of Energy and Environmental Protection to help control the blaze.
It was the second fire at that construction site on Thursday.