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Pressure cut in gas pipeline
Federal pipeline safety officials reacted swiftly and firmly to the possible threat posed by a natural gas pipeline rupture southeast of here, ordering an immediate 20-percent reduction in pressure on the entire 300-mile length of the 26-inch pipeline in the state. On the Eastside, the pipeline passes east of Redmond, across the Sammamish Plateau and through Issaquah. The federal Division of Pipeline Safety issued the corrective action order Friday, after the rupture Thursday, to Williams Northwest Pipeline, which is based in Salt Lake City. Williams operates one of two major transmission lines through Western Washington between Sumas in Canada and Washougal, Wash. `I find that resumed operation ... without corrective measures would be hazardous to life, property and the environment,'' wrote Stacey Gerard, association administrator for pipeline safety. `After considering the age of the pipe (put into service in 1956), the population near the pipeline in Western Washington, the seismic activity in the areas, the prior history of the pipeline and the lack of a determination as to the cause of the failure, I find that (failure to issue the order) would likely result in serious harm to life, property and the environment.'' Bev Chipman, corporate spokeswoman for Williams Northwest Pipeline, said that except for the pressure reduction, the company had already started many of the other corrective measures. She said the company would comply with all corrective measures, adding that the pressure reduction should be accomplished by late today. Chipman also said the ruptured pipeline could be fixed and transmitting gas as soon as Sunday. Finding out exactly what caused the 26-inch pressurized pipe to burst will take longer, she said. The rupture at 2:30 p.m. Thursday ripped a hole up to 12 feet deep, 20 feet wide and 100 feet long in the soft dirt. The initial explosion and flying dirt and rocks frightened many in the area east of the Top Food and Drug store on Lake Tapps Parkway East. About 100 people were evacuated. According to the Division of Pipeline Safety, the force of the explosion broke a 46-foot section of the pipe into pieces and catapulted them 250 feet from the rupture. About 21 feet of the pipe hadn't been recovered Friday afternoon. One large piece lay bent in two in the thick brush along the pipeline right of way. The force of the rupture filleted open the pipe almost flat. The roar of the escaping gas sounded like a jet engine, residents said. Fortunately the gas didn't burst into flames and no one was injured. Williams Northwest Pipeline crews were able to reroute the gas around the break via a parallel 30-inch line and the spewing gas was turned off after an hour. The 30-inch pipeline wasn't disturbed. Chipman said that no immediate cause was apparent to company crewmen or to federal and state regulators at the site. There were no immediate signs of corrosion and the electronic cathodic protection against corrosion installed along the pipeline was working, she said. She said crews planned to cut off the ends of the pipe still in the ground as well as the ends of the filleted section of pipe that was blown away. The sections will be shipped by truck to Metallurgic Consultants Inc. in Houston for analysis, she said. That analysis, which could take a week or more, may help explain what went wrong with the pipeline, she said. In the wake of Sept. 11, investigators for both the Federal Bureau of Investigation and the Bureau of Alcohol, Tobacco and Firearms were called in to investigate. They ruled out any criminal cause of the rupture, Chipman said. Also ruled out was any damage by a third party working in the area. Chipman said third party damage causes about 60 percent of pipeline failures. An inspector from the state Utilities and Transportation Commission was at the site Friday. The state took over interstate pipeline inspections two years ago after the Olympic Pipeline explosion in Bellingham which killed three people. Olympic is the other main transmission line through Western Washington. A UTC inspector will be on site until the pipeline is repaired. The state inspected the line in June of last year. The inspection was primarily a review of company documents to ensure all safety procedures and inspections were being done properly. The other corrective actions required of the Williams pipeline company after the Thursday rupture include: * Re-evaluating analyses of the previous four failures on the 26- inch pipeline in the past eight years and identifying any trends that may pose threats.. * Re-evaluating past in-line inspections of the line including the use of a`smart pig'' in 1996 to find out if any anomalies in the line could have contributed to the failure. A`smart pig'' is a tool that is run through the pipeline to examine it from the inside. * Evaluating the geotechnical character of the area of the failure. If anomalies are found, the company will expand the evaluation to the rest of the line. Failure to comply with the federal order could lead to civil penalties of as much as $100,000 per day. `We can drop the pressure (in the pipeline).'' Chipman said.`The most important thing when doing that is to make sure we can continue to supply or customers and meet our commitments. We need to make sure delivery and receiving points are compatible.'' Chipman said the pressure reduction shouldn't cause any problems for their customers unless the weather suddenly turned cold and the demand for gas increased. Copyright King County Journal
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