Two streets in Penhold were barricaded and traffic was diverted after a skid steer hit a gas riser, releasing levels of explosive gas on Tuesday afternoon.
The incident occurred at 2 p.m. in the 1200 block of Hwy 2A.
Crews from ATCO gas isolated the leak.
Fire crews ventilated a building adjacent to the incident for 30 minutes to bring explosive readings to zero and return oxygen levels to normal, said Penhold Fire Chief Jim Pendergast.
Fire officials left the scene by 3 p.m.
ATCO recommends that equipment operators do visual checks prior to operating machinery and that posts be in place to protect gas risers.