NTSB Safety Recommendation Letter P-84-001 through P-84-002

Page 1Official PDFNATIONAL TRANSPORTATION SAFETY BOARD WASHINGTON, D.C. ISSUED: January 20, 1984 Honorable Bill Sheffield Governor of Alaska Juneau, Alaska 99801 SAFETY RECOMMENDAT I O N (S) P-84-1 and -2 -----------__________________________I__----- On October 7, 1982, at 12:20 p.m. a.d.t., a contractor punctured the Enstar Natural Gas Company'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 the installation of piling around t h e house. Natural gas escaping from t h e ruptured service line at 50 psig migrated underground, entered the house, accumulated, and ignited at I:02 pm.; the source of ignition was not determined. The resultant explosion and fire destroyed t h e house, but no one was injured. The Anchorage Fire Department was notified of t h e explosion and fire at 1:03 p.m., arrived a t t h e site at 1:12 p.m., and extinguished the fire at 1:42 p.m. On July 20, 1982, several months before this accident, an engineering company had requested the gas company to mark the location of its gas service line to the house on East 17th Avenue. The gas company marked the location by spraying a decomposable paint on the ground above t h e service line, and the engineering company then excavated close to the house foundation without striking t h e 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 to locate its service line nor given the gas company advance notice of t h e excavation work. Eight months later, on June 15, 1983, another accident occurred this time 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 feet 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 the gas company before t h e contractor began work, but t h e pipeline depth had not been determined positively. The gas company serves about 50,000 customers in t h e 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 to the gas company statistics. 3839#

Page 2-2- The National Transportation Safety Board in its Special Study, "Prevention of Damage t o Pipelines" (NTSB-PSS-73-1), discussed t h e damage prevention responsibilities of excavators, contractors, and pipeline operators and concluded that: Pipeline accidents caused by excavation and construction activities, including blasting, can be prevented. . . .The operators of all underground systems must work together with local government officials, contractor associations, individual contractors, State officials, planners, and developers. . . .The assistance of t h e excavator and his machine operator in determining methods of and cooperation in avoiding damage should b enthusiastically sought. They should be educated as tb t h e damage and loss of life which they can cause and should be given as much assistance as necessary to 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 t h e public agencies or utilities listed in this paragraph t h a t the contractor has caused damage to any facility, equipment or installation of t h e agency and t h e contractor failed to request a utility locate service from t h e said utility at least four (4) normal business hours prior to the 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, 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 the said agency to provide t h e locate service requested. T h e 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/Department of Public Works Municipal Light & Power Utility This ordinance, while establishing a mechanism for compensating a utility for e caused damage, is not directed toward reducing hazards to public safety. The Safety Board has found t h a t t h e effectiveness of damage prevention e f f o r t depends on many interrelated factors such as convenient notification systems, educationa activities to advertise t h e systems, and efficient procedures for identifying and markin the location of underground facilities before excavation work begins. Moreover, based on its investigations, t h e Safety Board has concluded t h a t t h e most efficient and conven method for excavators to provide notice of proposed excavations is through t h e use one-call notification system. Such a system not only provides notification to pipeli#

Page 3-3- operators, but also t o operators of all other underground 'systems. In a one-call notification system, a n excavator makes one telephone call t o 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 the location of their lines near the work area. This early notification also provides the opportunity for operators of underground facilities t o 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 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 to 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 t 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 the Connecticut system, a &%percent reduction in excavation damage during the first year of operation of the 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, the Enstar Natural Gas Company is not a member of this organization. In a letter t o the 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: 1. Utilities a r e required, by ordinance, t o provide and locate within 4 working hours -- concern that 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 State 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 a r e a and t h a t your support is needed for developing an effective, uniform statewide damage prevention program in all areas where buried utilities a r e located.#

Page 4Therefore, the National Transportation Safety Board recommends t Governor of t h e State of Alaska: Through t h e Alaska Pipeline Commission and t h e Alaska Public Ut1 Commission, encourage and assist municipalities where undergroun facilities exist to develop and implernent a one-call excavatio notification and damage prevention system for ail areas of t h e Stat where underground utilities are located. (Class 11, Priority Actio (P-84-1) Request the Alaska S t a t e Legislature to enact legfslation requiring persons excavating or discharging explosives near underground utilities t o notify operators of public utilities in advance using a one-call notification svstem where i t is established. (Class 11, Priority Action) (P - 8 4 - 2) BURNET 1, Chairman, GOLDMAN, Vice Chairman, BURSLEY, ENGEN, and GROSE, Me1 rnbers, concurred in these recommenda#