NTSB Safety Recommendation Letter P-84-004

Page 1Official PDFNATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. ISSUED: January 20, 1984 Forwarded t o : Mr. Perry L. Johnson Vice President, Operations Enstar Natural Gas Company Post Office Box 6288 Anchorage, Alaska 99502 \ SAFETY RECOMMENDAT ION (S) P-84-4 ---------------___--I___________________----- On October 7, 1982, at 1 2 2 0 p.m. a.d.t., a contractor punctured t h e Enstar tural Gas Company's (gas company) .5/8-inch diameter plastic gas service line to a house at 8520 East 17th Avenue in Anchorage, Alaska; t h e contractor had been augering holes for t h e installation of piling around t h e house. Natural gas escaping from t h e ruptured service line at 50 psig migrated underground, entered t h e house, accumulated, and ignited at 1:02 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 the site at 1:12 p m . , and extinguished the fire at 1:42 p.m. On 3uly 20, 1982, several months before this accident, a n engineering company had requested the gas company to mark t h e location of i t s gas service line t o t h e 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 t h e engineering company then excavated close to the house foundation without striking the service line. However, a different contractor was engaged for the work on October 7 and this contractor had neither requested the gas company to locate its service line nor given t h e gas company advance notice of the 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 from t h e 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 t h e ruptured pipeline. In this accident, t h e pipe location had been marked by t h e gas company before the contractor began work, but t h e pipeline depth had not been determined positively. The gas company serves about 50,000 customers in the Anchorage area and receives about 1,100 requests from contractors each month to locate its gas lines. In spite of this extensive line location activity, natural gas pipelines in the Anchorage area 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- The National Transportation Safety Board in its Special Study, "Preventi Damage to Pipelines" (NTSB-PSS-73-1), discussed t h e damage prevention responsib of excavators, contractors, and pipeline operators and coiicluded that: Pipeline accidents caused by excavation and construction ac including blasting, can be prevented. . . .The operators of all ur 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 enthusiastically sought. They should be educated as to the damage and loss of life which they can cause and should be given as much assistance as necessary t o help them avoid hitting a pipeline (emphasis added). Article 6.26 -- "Utility Locate (sic) Requirement" of Anchorage's, "Municipal Standards Specifications" states: Upon receipt of written notification from any of the 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 the agency and the contractor failed to 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 the damage was not proximately caused by an error in the locate service, t h e Municipality of Anchorage will withhold from forthcoming or accrued contract payment, including advances, a s agent of one of t h e respective agencies listed below who is authorized by t h e said agency to provide t h e locate service requested. 'The public agencies or utilities t h a t may provide notice of facility damage under this paragragh 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/Depar t m e n t of Public Works Municipal Light & Power Utility This ordinance, while establishing a mechanism for compensating a utility caused damage, is not directed toward reducing hazards t o public safety. The Safety Board has found t h a t the effectiveness of damage prevention depends on many interrelated factors such as convenient notification syst activities to advertise t h e systems, and efficient procedures for identif t h e location of underground facilities before excavation work begins. Moreover, based on i t s investigations, t h e Safety Board has concluded t h a t t h e most efficie method for excavators to provide notice of proposed excavations is through t h e use of one-call notification system. Such a system not only provides notification to pipelin#

Page 3-3- operators, but also t o operators of all other underground systems. In a one-call notification system, an excavator makes one telephone call to a center established voluntarily by utilities and other operators of underground facilities (including municipalities), and notifies the center of planned excavations. The center then alerts all participants in the notification system about the planned excavation, which allows them timely opportunity t o mark t h e location of their lines near t h e work area. This early notification also provides the opportunity for operators of underground facilities t o under- take any additional action which may be necessary to 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 the U.S. Department of Transportation recently issued a rule directed at reducing the risks of excavation-caused damage t o underground gas pipelines. Operators of underground gas pipelines a r e allowed t o comply with the major aspects of the rule through participation in one-call notification systems because these ’I.. . programs have proven themselves cost effective. . . . I q 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 the first 2 years of operation of the Connecticut system, a 65-percent reduction in excavation damage during the 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 the 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 t o t h e Safety Board dated November 8, 1982, Enstar stated: W e do not belong to a one-call system. The local utility association has had several meetings concerning the one-call system, t h e utilities have not been able t o agree on implementation t o date. The primary stumbling blocks a r e as follows: I. Utilities a r e required, by ordinance, t o provide and locate within 4 working hours -- concern t h a t the inherent delay in a one-call system might make this already difficult deadline even more difficult. 2. Some utilities a r e not convinced the expenditure can be justified. The local Utility Association already has an active call before you dig program. The Safety Board is concerned about the increasing potential for pipeline accidents in Alaska. Although Alaska is a sparsely populated S t a t e now, i t is growing rapidly with increasing construction activities not only in the large and expanding municipal centers but also in t h e remote areas where crude oil and natural gas production and transportation facilities a r e under construction. The Safety Board believes t h a t while the Anchorage Area Utility Association is a s t a r t in the right direction, t h e problem goes beyond t h e Anchorage area and t h a t your support is needed for developing a n effective, uniform statewide damage prevention program in all areas where buried utilities a r e located.#

Page 4-4- Therefpre, t h e National Transportation Safety Board recommends t Natural Gas Company: Encourage other operators of underground facilities to join i establishment of a one-call excavation notification and dama prevention system in its a r e a of operation and assis implementation. (Class 11, Priority Action) (P-84-4) BURNETT, Chairman, 1 GOLDMAN, Vice Chairman, BURSLEY, ENGE AJnrnharr ---- . - - - A ' * I ' Lv.LI18wCI 9, LutIcuc r cu In tnis recommendation. Chair man#