Fort Saskatchewan fire chief James Clark says no one was hurt in the blast that happened just before noon Wednesday.
He says a track hoe digging into the ground struck a hydrogen gas line, which triggered a small explosion and fire.
Crews diverted traffic away from the area of the gas leak as a safety precaution for a few hours.
Clark says there are lots of pipelines in the area and the city had to consult with companies to determine what type of gas they were dealing with.
The area is part of Alberta's so-called Industrial Heartland — Canada's largest hydrocarbon processing region.
“We are thankful that the incident was quickly contained and no one was injured,” Clark said Wednesday.