Emergency crews respond Thursday to a structure fire on Somerville Road in Jefferson. Anna Chadwick/Morning Sentinel

JEFFERSON — Firefighters from nearly a dozen communities in three counties worked for about five hours Thursday to knock down a fire at a former industrial building that has been housing a marijuana grow facility.

Jefferson Fire Chief Darin Walker said once firefighters realized the building was being used for marijuana cultivation, they changed their approach to fighting the fire.

“That changes our attack 100%,” Walker said. “It takes a whole different approach to things. When marijuana facilities are burning, they are considered hazardous material, because of all the stuff that’s in there. It’s not just the marijuana that’s burning, but it’s all the potential chemicals they use — the fertilizers, and you got propane, you got butane.”

Firefighters were initially called to the scene shortly before 12:30 p.m., and when they arrived they found a three-story metal building with heavy smoke showing and starting to vent out of the roof.

The building, the former W/S Enterprises Machining and Fabrication, appears to be a single-story building from Somerville Road, but because of the slope of the land, the rear of the building is three stories tall.

Walker said because the chief from Whitefield and the deputy Jefferson fire chief arrived promptly, they were able to size up the fire and the property and deploy the Waldoboro Fire Department’s ladder truck behind the building when it arrived. In that location, firefighters were able to put water right over the grow area.

Emergency crews respond to a structure fire Thursday on Somerville Road in Jefferson. Anna Chadwick/Morning Sentinel

Because of the size of the fire, a second alarm was struck to bring in more firefighters to help carry water from two nearby locations on the Sheepscot River, he said, at the Coopers Mills dam and at the boat launch off Barton Road, to douse the fire.

Jefferson property records show 147 Somerville Road is owned by Jabanc LLC. The building and the 51-acre parcel it’s located on is valued for taxation at $465,000.

Walker said while the building on the property had been empty for quite a few years, it had been leased out to a cannabis grower.

“The fire department, nor the code enforcement officer nor the town administrator had any idea there was a grow going on that property,” he said.

Emergency crews spent five hours battling a structure fire Thursday on Somerville Road in Jefferson. While the building had been vacant, it had been leased to a cannabis-growing operation. Anna Chadwick/Morning Sentinel

Not knowing that a facility is being used to grow cannabis can affect the safety of firefighters, he said. Firefighters had entered the building to fight the fire, but pulled out and fought it only from the outside once they realized what the building was being used for.

Walker said the Office of State Fire Marshal was called to investigate.

On Friday, Shannon Moss, public information officer for the Maine Department Public Safety, said fire marshals determined the fire was accidental and started in a heat pump.

Firefighters from Jefferson, Somerville, Whitefield, Nobleboro, Waldoboro and Newcastle in Lincoln County; Randolph, Pittston, Chelsea and Windsor in Kennebec County; and Washington in Knox County responded to the fire.

Kennebec Journal staff writer Emily Duggan contributed to this report.