NTSB Safety Recommendation Letter P-83-005

Page 1Official PDFNATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. ISSUED: January 27, 1983 Mr. Robert D. Bugher Executive Director American Public Works Association 1313 East 60th Street Chicago, Illinois 60637 SAFETY RECOMMENDAT I O N ( S ) P-83-5 -_------_-------_-----~-----------~---,----~-- I A t 3:20 a.m., m.d.t., on June 28, 1982, a natural gas explosion demolished a house, killed five persons, and critically injured one person a t 827 West 18th Street in Portales, New Mexico; the critically injured person died later at a burn treatment center. The gas service line to the house had been damaged 37 days earlier when a contractor's backhoe pulled up the line during conduit excavation work for the local telephone company. A t the same time the line was pulled out at the excavation site, the line was pulled out of a cornpression coupling buried under the street. The pullout at the excavation site was repaired, but the pullout under the street was not repaired until after this accident because the gas compmy did not detect it when it happened. lJ The gas service line involved in this accident was part of a typical residentid gas service operation. The 3/4-inch-diameter gas service line extended approximately 63 feet from the 2-inch-diameter gas main to the property line of 827 West 18th Street, where it was connected to the customer's 1 ll4-inch-diameter service line, which extended 30 feet to the gas meter on the front of the house. The gas in the system was transmitted at a 25-psig to 60-psig pressure. The gas main and service line were buried at a depth of 28 inches. The house at 827 West 18th Street was the only one on that block that had gas service from the front. Other gas service lines in the area were connected to a 2-inch gas main in an alley behind the 800 block of West 18th Street. In 1966, the gas company replaced an old 2-inch-diameter gas main along West 18th Street with a new, coated, wrapped, and cathodically protected 2-inch-diameter steel main. A t that time, the bare steel 1 1/4-inch-diameter service line to 827 West 18th Street was replaced with a new 3/4-inch-diameter, coated, and wrapped steel line. The old line was abandoned in place, and the new line was connected with a compression coupling to the existing 1 l/4-inch customer service line at the property line. Later in 1966, the city of Portales installed a water line in the middle of West 18th Street, and to facilitate the construction of the water line, the city asked the gas company to cut the gas service line to 827 West 18th Street. When the water line installation was completed, the gas company reconnected the gas service line by installing two compression couplings and reconnecting the service line. The area was then backfilled, and the road surface was repaved. - 1/ For more detailed information, read Pipeline Accident Report--"The Gas Company of New Mexico, Natural Gas Explosion and Fire, Portales, New Mexico" (NTSB-PAR-83-1). 3662#

Page 2-2 - The contractor stated that he had visited the gas company to look at maps identify locations where the proposed conduit crossed the gas mai stated that the gas company told him that he would not encounter any West 18th Street until he began to excavate west of South Avenue I. stated that gas company personnel and telephone company personnel stopped by s times each day to talk and observe the work he was performing. The contractor stated that a gas company employee had informed him ea there were no gas lines in the 800 block of West 18th Street between Go and South Avenue I, and that all service lines for the residential housing in that block were run from the alley behind and not from the front of the property on the street. The gas company has denied that the gas company employee gave the contractor such information. The maps for the gas mains in Portales are aerial photos of the city the gas mains. The gas company does not enter its gas service lines on tt In its investigations of pipeline accidents in Greenwich, Connecti Willianisport, Pennsylvania, on January 25, 1977, and in Mansfield the Safety Board found that the inaccuracy of, or the lack of, syste contributed to the accidents. The gas company's Operating and Maintenance Plan, "Operations Mapping, states that maps shall be kept in detail and up to date. Contrary to this s direction, however, maps were not available showing the location of 827 West 1 8 t h Street or any other service line in that area. If house at 827 West 18th Street had been shown on the gas comp would have been pointed out to the contractor and marked. service lines prevented the gas company personnel who discussed the project with the contractor and with the telephone company from identifying all of th gas company's facilities on West 18th Street and marking them. company personnel and the contractor had met with gas company personnel before a during the project and because these meetings had resulted in precautions taken locations shown on gas company maps where the conduit crossed the g Board believes that had the service line to 827 West 18th Street been made known to t contractor and marked at the site before excavation, it too would h from damage, and this accident would not have happened. Although there is no one-call excavation notification system in the Port and although there had been no formal one-group preconstruction excavation involved in this accident, all parties (the telephone co Portales, and the gas company) knew that a conduit was being i do the work, and knew when the work was to be done. Although th worked before on Sundays, when gas company employees were normally off duty, although the contractor did not tell the gas company that he planned to work on Sun both the contractor and the telephone company believed, based on their assertion they had been told so by gas company employees, that after the contractor had crosse the gas main a t Golden Acres Avenue, he would not encounter any more gas lines unt west of South Avenue L The contractor stated that gas company e m all of the houses in the 800 block of West 18th Street (between A supplied by gas service lines from the alley behind the houses. asserts that its employees deny giving such information, the Safe gas company employees probably did do so, because when they arrived at the burnin house the night of the accident, they spent 5 to 10 minutes looking for the gas meter i the alley behind the house. The Safety Board thus believes that the gas company did n give the contractor accurate information as to the location of the gas lines involved in th accident.#

Page 3-3- Therefore, t h e National Transportation Safety Board recommends t h a t t h e American Public Works Association: Notify its members of the circumstances of the accident in Portales, New Mexico, on June 28, 198!, and urge them to cooperate with t h e pipeline operator in determining t h e extent of damage when pipeline facilities have been damaged. (Class 11, Priority Action) (P-83-5) The National Transportation Safety Board is an independent Federal agency with t h e statutory responsibility It. . . to promote transportation s a f e t y by conducting independent accident investigations and by formulating safety improvement recommendations." (P.L. 93-633). The Safety Board is vitally interested in any actions taken as a result of i t s s a f e t y recommendationfs). Therefore, we would appreciate a response from you regarding action taken or contemplated with respect to t h e recommendation in this letter. BURNETT, Chairman, and McADAMS, BURSLEY, and ENGEN, Members, concurred in this recommendation. GOLDMAN, Vice Chairman, did not participate. Chairman#