Washington Regulators Release Report into March Gas Explosion in Seattle

Washington pipeline safety regulators today released their investigation report into the March 9 natural gas explosion in the Greenwood neighborhood of Seattle.
Utilities and Transportation Commission’s Pipeline Safety staff led the investigation into the cause of the explosion that injured nine firefighters and caused extensive property damage.
The investigation found the immediate cause of the explosion was outside force applied by unauthorized individuals to a gas service line owned by Puget Sound Energy. The damage allowed gas to escape, accumulate in the building occupied by Mr. Gyros restaurant, and ultimately explode.
The broken gas service line was one that PSE records showed as abandoned in 2004. At the time, PSE failed to properly disconnect and seal the line, allowing it to remain in service for nearly 12 years without proper oversight.
As a result of the investigation, the UTC filed a formal complaint against PSE alleging the company committed 17 violations of pipeline safety regulations and recommended a penalty of up to $3.2 million.
The complaint will be scheduled for a hearing before the three-member commission. The commission is not bound by staff’s recommendation.
Pipeline Safety staff allege that PSE violated pipeline safety regulations by failing to:
• Abandon a service line according to federal standards;
• Follow its internal pipeline deactivation plan;
• Perform annual leak surveys of an active service line;
• Perform atmospheric corrosion tests of an active service line at least once every three years; and
• Perform external corrosion tests of an active service line at least once every 10 years.
The gas service line that PSE believed was abandoned in 2004 was located in a space not intended for human occupancy between the Mr. Gyros and Neptune Coffee businesses. Evidence at the scene and witness interviews indicated that the space around the gas line was frequently used by unauthorized individuals to store personal items. Individuals acknowledged to investigators that due to the limited space, they sometimes disturbed the gas line to access the area.
Lab tests confirmed the line failed at the threaded connection due to applied external force.
Staff also recommended the commission require PSE to review all previously abandoned service lines to verify compliance and provide a plan for identifying and mitigating any additional unsuccessful retirements.
Related News
Related News

- Enbridge Plans 86-Mile Pipeline Expansion, Bringing 850 Workers to Northern B.C.
- Intensity, Rainbow Energy to Build 344-Mile Gas Pipeline Across North Dakota
- U.S. Moves to Block Enterprise Products’ Exports to China Over Security Risk
- 208-Mile Mississippi-to-Alabama Gas Pipeline Moves Into FERC Review
- Court Ruling Allows MVP’s $500 Million Southgate Pipeline Extension to Proceed
- U.S. Pipeline Expansion to Add 99 Bcf/d, Mostly for LNG Export, Report Finds
- A Systematic Approach To Ensuring Pipeline Integrity
- 275-Mile Texas-to-Oklahoma Gas Pipeline Enters Open Season
- LNG Canada Start-Up Fails to Lift Gas Prices Amid Supply Glut
- Kinder Morgan Gas Volumes Climb as Power, LNG Demand Boost Pipeline Business
Comments