Two major gas pipeline blowouts in last 72 hours (Louisiana and Texas)

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Infrastructure problems with gas and oil pipelines were predicted at rollover. Following the reports, I am posting a report/alert issued by the US DOT last year that explains the potential y2k problems with gas pipelines.

Two major gas pipeline blowouts in 24 hours

Gas line rupture likened to booms Source: Saturday State Times/Morning Advocate

Publication date: Jan 29, 2000

BLANCHARD - About 50 residents had to evacuate their homes for two hours Thursday when a natural gas line blew. "It sounded like three sonic booms going off at once," said Dick Bostwick, 82, who was reading the newspaper when the 20-inch line blew.

There was no fire or explosion and nobody was hurt. The boom was caused by gas escaping, officials said. The line was bypassed to keep natural gas flowing to Shreveport, said Richard Wheatley, a spokesman for Reliant Energy in Houston.

Bostwick's home and others scattered within a mile of the rupture were ordered evacuated because of the potential danger the escaping gas posed. It wasn't immediately known if the blowout was caused by Thursday's cold snap.

Cold temperatures can contribute to gas line blowouts by causing the ground to shift or moisture around pipes to freeze. Evacuees were allowed to return to their homes after gas was shut off to the line off La. 173 in the Caddo Parish community just north of Shreveport.

A valve was closed in the ruptured line, and gas was routed to a secondary line. A spokesman for Reliant Energy Gas Transmission said pieces of the ruptured line will be analyzed to determine the reason for the failure. Not many of the evacuated homes actually lost heat.

Reliant spokesman Scott Mundy said only one home lost gas service.

Some evacuees stayed with friends and relatives while others went to a makeshift shelter set up at Northwood High School.

Publication date: Jan 29, 2000 ) 1999, NewsReal, Inc.

http://beta.newsreal.com/cgi-bin/NewsService?osform_template=pages/newsrealStory&ID=newsreal&storypath=News/Story_2000_01_30.NRdb@2@3@3@121&path=News/Category.NRdb@2@16@2@1

200 evacuated after Boyd gas line blast By Bill Hanna

Star-Telegram Staff Writer

A natural gas pipeline explosion jolted residents of the southern Wise County town of Boyd from their sleep Thursday night, forcing the evacuation of about 200 people and leaving the town without gas for heat as temperatures plunged below freezing. Residents were able to return to their homes about 3 a.m. yesterday, and repairs to the pipeline were completed about 5:30 p.m. yesterday, said TXU spokeswoman Carol Peters.

"It was quite a boom, I can tell you that," said Boyd Mayor Allen Dickey. "I thought it sounded like a big jet airplane. I just never heard a sound quite like that."

The pipeline burst just north of Boyd in a pasture near Farm Road 730, sending natural gas across the northern quarter of the Wise County town. A person staying in a house about 200 yards away was not injured, authorities said.

Firefighters and law enforcement personnel went door to door, telling residents north of Texas 114 that they had to leave their homes. The remainder of the people in town were awakened and told to turn off gas appliances.

"We started assigning everyone to a specific street and got the evacuation done in about 45 minutes," said Jeremy McEntire, the assistant chief of the Boyd Volunteer Fire Department and a member of the City Council.

"We got everyone to the community center and the high school. There was heat at the community center, so everyone was able to stay warm," he said.

Classes were canceled at Boyd schools yesterday.

"We were really lucky that there was no fire, no injuries, no loss of life," McEntire said. "We have been talking for years about getting an emergency evacuation plan in place, and I think this will be the wakeup call to get us to move ahead and get one in place like the bigger cities."

The pipeline, which originates southwest of Boyd in Eastland County, was handling 680 pounds of pressure at the time of the accident. It was certified to withstand 800 pounds of pressure.

"We don't know why this happened," Peters said. "It wasn't under any extreme pressure. We are prepared for winter."

TXU workers pumped a mixture of propane and oxygen into the lines until natural gas service could be restored, Peters said.

Bill Hanna, (817) 390-7698

Send comments to billhanna@star- telegram.com

Link to story:

http://www.star-telegram.com/news/doc/1047/1:STATE61/1:STATE610128100.html

____________________________________________________________ ____________________________________________________________

U.S. Dept. of Transportation Office of Pipeline Safety

PIPELINE SAFETY ADVISORY BULLETIN

ADVISORY BULLETIN: ADB-99-03 Date: July 7, 1999

To: Owners and Operators of Hazardous Liquid and Natural Gas Pipeline Facilities

Subject: Potential Service Interruptions in Supervisory Control and Data Acquisition Systems

Purpose: Inform pipeline system owners and operators of potential operational limitations associated with Supervisory Control and Data Acquisition (SCADA) systems and the possibility of those problems leading to or aggravating pipeline releases.

Advisory: Each pipeline operator should review the capacity of its SCADA system to ensure that the system has resources to accommodate normal and abnormal operations on its pipeline system. In addition, SCADA configuration and operating parameters should be periodically reviewed, and adjusted if necessary, to assure that the SCADA computers are functioning as intended. Further, operators should assure system modifications do not adversely affect overall performance of the SCADA system. We recommend that the operator consult with the original system designer.

Background: During an Office of Pipeline Safety (OPS) investigation of a recent pipeline incident, OPS inspectors identified inadequate SCADA performance as an operational safety concern. Immediately prior to and during the incident, the SCADA system exhibited poor performance that inhibited the pipeline controllers from seeing and reacting to the development of an abnormal pipeline operation.

Preliminary review of the SCADA system indicates that the processor load (a measure of computer performance utilization) was at 65 to 70 percent during normal operations. Immediately prior to an upset condition occurring on the pipeline, the SCADA encountered an internal database error. The system attempted to reconcile the problem at the expense of other processing tasks. The database error, coupled with the increased data processing burden of the upset condition, hampered controller operations. In fact, key operator command functions were unable to be processed immediately prior to and during the abnormal operation. It is possible that post installation modifications may have hampered the system's ability to function appropriately.

The combination of the database error, the inadequate reserve capacity of the SCADA processor, and the unusually dynamic changes that occurred during the upset condition, appear to have combined and temporarily overburdened the SCADA computer system. This may have prevented the pipeline controllers from reacting and controlling the upset condition on their pipeline as promptly as would have been expected.

For further information, contact Chris Hoidal, Director, OPS Western Region at 303-231-5701. Back to CSB Home Page

Link to report:

http://chemsafety.gov/y2k/brochure9907.htm



-- Carl Jenkins (Somewherepress@aol.com), January 30, 2000


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