PORTLAND -- A transfer station on Sauvie Island loudly vented natural gas for about an hour Friday morning, prompting an evacuation a quarter-mile around the site.
The Sauvie Island Bridge was closed as part of the incident at a plant operated by Williams Pipeline. The venting was first reported just before 6 a.m. and ended about 7 a.m.
A Williams official told KGW that a torn diaphragm on a pressure gauge created a leak that led to the venting. The Sauvie Island facility gets gas from Canada and reduces pressure levels suitable for use by Northwest Natural Gas.
Marc Alifanz told KGWthe venting was very loud and rhythmic, like ocean waves but much louder. The sound woke up his family and could clearly be heard over his phone.
He has lived off Highway 30 looking down on the island for six years and has never heard or seen anything like it from the gas facility. His home is about a half mile from the plant.
Lt. Rich Chatman of the Portland Fire & Rescue Bureau said the vents were doing their job of easing excess pressure. The vented gas rises and does not pose a health hazard in general. There is concern about gas getting into nearby buildings, he said.
Any evacuated residents were taken to the parking lot of Sauvie Island School, which announced that it would be closed Friday.
Alifanz shot this video on his iPad that captures the roar of the venting.