NTSB Safety Recommendation Letter P-80-048 through P-80-049

Page 1Official PDFWASHINGTO ISSUED: June, 3, 1980 Forwarded to: \ Mr. E. R. Turnquist Vice President and General Manager klountain Bell Telephone Company 201 3rd Street, N.W. Albuquerque, N e w Mexico 87102 SAFETY RECOMMENDATION(S) P-80-48 and -49 --------------------____________________- I A t 5:51 p.m., m.d.t., on J u l y 25, 1979, an explosion and fire destroyed a duplex apartment house at 2301 Bridge Boulevard, Albuquerque, N e w Mexico. Two persons were killed, and two persons were hospitalized for burns; adjacent houses were damaged. Earlier i n the day, a crew from Mountain Bell Telephone Companv (Mountain Bell) had been using a backhoe at the intersection of Bridge Boulevard and Atrisco Road to locate a telephone cable. The backhoe snagged a gas service line but the fact that i t was pulled from a 1-inch coupling under the house was not discovered at that time. Some of the residents i n the area stated that they had smelled natural gas odors beginning at noon of that day, hut no one had called the gas company or the fire depart m ent. Natural gas, fit 38 psig pressure, escaped from the service line and accumulated under the house. The gas ignited when one of the occupants struck a match to light a stove. .,,., The Gas Company of N e w Mexico, owner of the gas service line, is a member of the local "Blue Stake-one-call" system. The Blue Stake OneCall Center had received a telephone call from Mountain Bell Telephone Company on July 24, 1979, requesting that the gas company mark the location of the service line a t 2301 Bridge Boulevard. Although the request was not in compliance with the gas company's requirement for 48 hours' advance notice to locate and mark its facilities before excavation, gas company employees arrived at the location on the morning of the accident to mark the service line. They noticed that the telephone company's construction crew had already uncovered and exposed a portion of the service line. The construction crew was not aware of the exact location of the natural gas service line until they had snagged it with the backhoe. The gas company employees proceeded to locate the service line, as requested, and sprayed paint on the surface of the pavement above the service line. No inspection of the exposed service line was made, and no discussion of the prior excavation took place between gas company and telephone company personnel. 2943#

Page 2-2- After the accident, the service line was exposed from the excavation site to a crawl space under the apartment house where it had been pulled from its compression coupling. A ?,-inch separation existed between the inlet side of the compression coupling and the pipe. The 3/4-inch steel mill wrapped service line was approximately 7 5 feet from the top of the main to the house meters and hrtd been bent severely 1 1 inches horizontally and 6 inches vertically at the excavation site. Examination of the service line at the excavation site showed that the service line had been taped over the bent area. It is Mountain Bell's policy to tape any facility which it has struck during excavation work. The Safety Board determined that Mountain Bell began excavating for the telephone cable and damaged the natural gas service line before the service line was properly marked by the gas company. Therefore, the National Transportation Safety Board recommends that the Mountain Bell Telephone Company: Direct its excavation contractors as well as its company crews not to begin excavation operations until underground facilities have been marked properly, and when facilities are damaged as a result of excavation activities, to immediately notify the owner so that inspection, repair, or other emergencv actions can be initiated. (Class II, Priority Action) (P-80-48) When gas facilities are disturbed or damaged, take necessary precautions in coordination with gas company instructions, such as evacuation of adjacent buildings, to ensure the safety of the public. (Class 11, Priority Action) (P-80-49) KING, Chairman, DRIVER, Vice Chairman, McADAMS, GOLDMAN, and BURSLEY, Members, concurred in these recommendations.#