At 0835hrs Station 36 was dispatched to South Hampton At Waterford for a heavy odor of natural gas. Tanker 36, Rescue 36, and Truck 19 arrived to find a heavy odor of natural gas in an apartment. Crews pulled a line and while wearing SCBA’s located the source of the leak. The apartment was ventilated. Maintenance staff was called to correct the issue. Equipment returned to service at 0921hrs.