An “improperly abandoned” Puget Sound Energy (PSE) gas pipeline was the cause of an explosion in Greenwood that leveled two buildings and damaged nearly three dozen businesses in March 2016, a new report finds.
PSE could be subject to up to $3.2 million in penalties.
The Washington Utilities And Transportation Commission released the report Tuesday. Investigators concluded that human activity was likely the immediate cause of the gas leak — but that the leak would not have occurred had the utility company PSE followed safety regulations when they abandoned the pipe in 2004.
What Caused The Gas Leak?
The gas leak occurred in a narrow space between a restaurant and a coffee shop, where an above-ground portion of the gas pipeline was located. According to investigators, people used the space to store personal property and would sometimes trip over the service line. This human activity damaged a threaded coupling (or, a fastener) on the pipeline, which caused gas to leak into the restaurant.
What Was PSE’s Role?
According to the report, the explosion would not have occurred (regardless of damage from people tripping over and bumping into the pipe) if PSE had followed regulations when closing the pipeline in 2004.
Because PSE did not properly “cut and cap” the line it remained active and gas was allowed to leak into the property years later.
PSE violated a number of safety regulations when they abandoned the pipe, including: failure to properly abandon the service line, failure to follow its internal pipeline deactivation plan, failure to perform annual leak surveys of the active service line, and failure to perform atmospheric corrosion tests of the service line.
Firefighters were called to the scene of the gas leak in Greenwood just after 1:00 a.m. on March 9.
After locating the gas leak between the restaurant (Mr. Gyros) and coffee shop (Neptune coffee), firefighters walked to another area where they waited for PSE to arrive.
At 1:40 a.m., the gas ignited and caused a massive explosion, leveling the two buildings that housed Mr. Gyros, Neptune Coffee, and a convenience store.
Nine firefighters were injured in the blast, which also damaged 36 neighboring businesses.