Federal investigators still aren’t sure what caused last year’s explosion that injured five workers at a liquefied natural gas plant in Plymouth, Washington, though repairs are underway to bring the facility back to full operation.
Williams Northwest Pipeline, which owns the plant, is spending $69 million to repair damages on site, including a large storage tank punctured by shrapnel in the explosion shortly before 8:20 a.m. on March 31, 2014.
Natural gas from the damaged tank was emptied and transferred into a second undamaged tank, where it remains available for customers during peak wintertime demand. Michele Swaner, a spokeswoman for Williams Northwest based in Salt Lake City, said the damaged tank should be fixed by April and full operations resumed at the plant by November.
The Plymouth facility — located across the Columbia River from Umatilla — is used for storing of natural gas off the main Northwest pipeline. Gas is cooled into a liquid state at minus 260 degrees Fahrenheit, and held in the identical tanks until needed elsewhere throughout the region. Both tanks are capable of holding up to 14 million gallons of material.
With approximately 3,900 miles of transmission pipe, the Williams Northwest Pipeline is the main artery for carrying natural gas through Washington, Oregon, Idaho, Wyoming, Utah and Colorado.
Last year’s explosion forced residents living within a mile of the facility to evacuate their homes for more than a day while emergency responders dealt with the threat of leaking natural gas. Five employees were treated for injuries, including one who was sent to a Portland hospital with burns.
An investigation into the incident is now being led by the U.S. Department of Transportation’s Pipeline Hazardous Materials Safety Administration. Their findings will be made public once all the information is gathered, Swaner said.
It is not yet known whether the incident was accidental or caused by employee error. Based on those findings, Swaner said the company will take a closer look at procedures to see how they can avoid a similar event in the future.
“Until we really understand what happened at the facility, we don’t want to talk about procedures,” she said.
Company officials held a public meeting in Plymouth a week after the explosion, and Swaner said they hope to return by spring or summer with more information to share with the community. Prior to the blast, the Washington Utilities and Transportation Commission last inspected the Plymouth facility in November 2013 and reported no violations.
Swaner said the company takes safety very seriously, although they dealt with a number of dangerous mishaps in 2014. Those included Plymouth, a pipeline explosion in West Virginia and gas plant explosion in Opal, Wyoming.
“These are things we don’t want to happen,” Swaner said. “We do look at our safety record, but we have to understand why we’re having these incidents.”
Williams Northwest filed notification with the Federal Energy Regulatory Commission on July 2, 2014, of its plans to repair the Plymouth facility in three phases. Most structures have already been repaired, and Swaner said employees are back to work.
Contact George Plaven at email@example.com or 541-564-4547.