NTSB Safety Recommendation Letter P-84-003

Page 1Official PDFNATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. ISSUED: January 20, 1384 Forwarded to: Mr. Robert Phillips President Anchorage Area Utility Association c/o Matanuska Electric Association, Inc. Post Office Box 1148 Palmer, Alaska 99645 SAFETY RECOMMEN'DAT I O N (SI P-84-3 On October 7, 1982, at 12:20 p.m. a.d.t., a contractor punctured t h e Enstar Natural Gas C,ompany's (gas company) 5/8-inch diameter plastic gas service line to a house at 8520 East 17th Avenue in Anchorage, Alaska; the contractor had been augering holes for t h e installation of piling around the house. Natural gas escaping from the ruptured service line at 50 psig migrated underground, entered t h e house, accumulated, and ignited at I:02 pm.; the source of ignition was not determined. The resultant explosion and fire destroyed the house, but no one was injured. The Anchorage Fire Department was notified of the explosion and fire at 1:03 pm., arrived at t h e s i t e at 1:12 pm., and extinguished the fire at l:42 p.m. On July 20, 1982, several months before this accident, a n engineering company had requested the gas company t o mark t h e location of i t s gas service line to the house on East 17th Avenue. The gas company marked the location by spraying a decomposable paint on t h e ground above t h e service line, and the engineering company then excavated close to the house foundation without striking the service line. However, a different contractor was engaged for t h e work on October 7 and this contractor had neither requested the gas company t o locate i t s service line nor given t h e gas company advance notice of t h e excavation work. Eight months later, on June 15, 1983, another accident occurred this t i m e involving t h e gas company's 12-inch-diameter, high-pressure gas pipeline. The line was struck and ruptured by a bulldozer which was grading a new section of road in Anchorage. Gas at 650 psig escaped Lrom the ruptured pipe, blasting dirt, gravel, and rocks 200 to 300 f e e t in t h e air. One person was injured by the flying debris. Sixty to 70 residents were evacuated from their homes until gas company personnel closed valves on the ruptured pipeline. In this accident, the pipe location had been marked by t h e gas company before the contractor began work, but the pipeline depth had not been determined positively. The gas company serves about 50,000 customers in the Anchorage a r e a and receives about 1,100 requests from contractors each month t o locate its gas lines. In spite of this extensive line location activity, natural gas pipelines in the Anchorage a r e a were struck 410 times in t h e course of excavation operations in t h e 6-month period from January to June 1983, according t o the gas company statistics. 3839#

Page 2-2- including blasting, can be prevented.. . .The operators of all u systems must work together with local government officials, associations, individual contractors, S t a t e officials, planners, a developers. . . .The assistance of the excavator and his machine operator in determining methods of and cooperation in avoiding damage should be Upon receipt of written notification from any of t h e public agencies or utilities listed in this paragraph t h a t t h e contractor has caused damage to any facility, equipment or installation of t h e agency and t h e contractor failed t o request a utility locate service from t h e said utility at least four (4) normal business hours prior to t h e damage, or if t h e locate service was properly requested, t h a t t h e damage was riot proximately caused by an error in the locate service, the Municipality of Anchorage will withhold from forthcoming or accrued contract payment, including advances, as agent of one of the respective agencies listed below who is authorized by t h e said agency to provide the locate service requested. The public agencies or utilities t h a t may provide notice of faciliry damage under this paragragti are: Alaska Gas & Service Company Alaska Pipeline Company Anchorage Sewer & Water Utility Anchorage Telephone Utility Central Alaska Utilities, Inc. Chugach Electric Association, Inc. Matanuska Electric Association Matanuska Telephone Utility Municipality of Anchorage/Department of Public Works Municipal Light & Power Utility one-call notification system. Such a system not only provides notification to pipelin#

Page 3-3- operators, but also to operators of all other underground systems. In a one-call notification system, a n excavator makes one telephone call to a center established voluntarily by utilities and other operators of underground facilities (including municipalities), and notifies t h e center of planned excavations. The center then a l e r t s all participants in t h e notification system about t h e planned excavation, which allows them timely opportunity to mark the location of their lines near t h e work area. This early notification also provides t h e opportunity for operators of underground facilities to under- t a k e any additional action which may be necessary t o prevent excavation-caused damage. The one-call systems formed by operators of underground utilities now operate in 44 States, including the District of Columbia, with a majority of these systems providing statewide coverage. The Materials Transportation Bureau (MTB) of t h e US. Department of Transportation recently issued a rule directed at reducing t h e risks of excavation-caused damage to underground gas pipelines. Operators of underground gas pipelines a r e allowed t o comply with t h e major aspects of t h e rule through participation in one-call notification systems because these 'I. . . programs have proven themselves cost effective. . . ." Examples of the effectiveness of one-call notification systems cited by t h e MTB included a 38-percent reduction in excavation-caused damage t o underground facilities during t h e first 2 years of operation of t h e Connecticut system, a 65-percent reduction in excavation damage during t h e first year of operation of t h e Tampa, Florida, system, and a consistent annual reduction in excavation damage since 1970 for t h e Rochester, New York, notification system -- one of t h e first one-call systems. An Anchorage Area Utility Association now exists with a membership of seven electric, telephone, water, sewer, and cable utilities and an associate membership of four other utilities; however, t h e Enstar Natural Gas Company is not a member of this organization. In a l e t t e r to t h e Safety Board dated November 8, 1982, Enstar stated: We do not belong to a one-call system. The local utility association has had several meetings concerning t h e one-call system, t h e utilities have not been able to agree on implementation t o date. The primary stumbling blocks a r e as follows: 1. Utilities a r e required, by ordinance, to provide and locate within 4 working hours -- concern t h a t t h e inherent delay in a one-call system might make this already difficult deadline even more difficult. 2. Some utilities a r e not convinced t h e expenditure can be justified. The local Utility Association already has a n active call before you dig program. The Safety Board believes that t h e rapidly increasing construction activity in t h e expanding Anchorage a r e a requires a more effective underground utility damage prevention program than now is ir! place. The Safety Board believes t h a t while t h e Anchorage Area Utility Association is a s t a r t in t h e right direction, support is needed for developing an effective, uniform excavation notification and damage prevention program throughout t h e Anchorage area. Moreover, we believe t h a t programs in t h e Anchorage a r e a would provide impetus to a statewide one call system which t h e Safety Board has recommended t h e Governor of Alaska to promote and which i t urges you to support.#

Page 4-4- Therefore, t h e National Transportation Safety Board recomm Anchorage Area Utility Association, Inc.: Encourage and assist operators of underground facilities, legislature, and t h e rnunicipafities within t h e State of Alaska in t h e development and implementation of a one-call excavation notificatio and damage prevention system for all areas of t h e S t a underground utilities a r e located. (Class 11, Priority Action) (P-84-3) BURNE TT, Chairman, GOLDMAN, Vice Chairman, BURSLEY, ENGE Members, concurred in this recommendation. Y#