NTSB Number: SS-97-0l
NTIS Number: PB97-917003
Adopted December 16, 1997
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Pipeline accidents result in fewer fatalities annually than accidents in the other modes of transportation; however, a single pipeline accident has the potential to cause a catastrophic disaster that can injure hundreds of persons, affect thousands more, and cost millions of dollars in terms of property damage, loss of work opportunity, community disruption, ecological damage, and insurance liability. Excavation and construction activities are the largest single cause of accidents to pipelines. Data maintained by the U.S. Department of Transportation, Research and Special Programs Administration (RSPA), Office of Pipeline Safety, indicate that damage from outside force is the leading cause of leaks and ruptures to pipeline systems, accounting for more than 40 percent of the reported failures. According to the data, two-thirds of these failures are the result of third-party damage; that is, damage caused by someone other than the pipeline operator. Reports from the 20th World Gas Congress confirm that excavator damage is also the leading cause of accidents in other countries.
According to the Network Reliability Steering Committee (NRSC), an industry group appointed by the Federal Communications Commission, excavation damage is also the single largest cause of interruptions to fiber cable service. Network reliability data, compiled since 1993 by the NRSC, show that more than half of all facility outages are the result of excavation damage (53 percent). The Safety Board's review of NRSC first quarter data for 1997 indicates that this relationship has not changed. In addition to being expensive and inconvenient, disruption of the telecommunications network can have significant safety implications, such as impact on traffic control systems, health services, and emergency response activities. The Federal Aviation Administration's (FAA) study of cable cuts in 1993 documented 1,444 equipment outages or communications service disruptions resulting from 590 cable cuts nationwide over a 2-year period. The majority of cable cuts were related to construction and excavation activities. For 1995, the FAA's National Maintenance Control Center documented cable cuts that affected 32 air traffic control facilities, including 5 en route control centers. Cable cuts for the first 8 months of 1997 affected air traffic control operations for a total of 158 hours.
The U.S. underground infrastructure comprises about 20 million miles (32.2 million kilometers) of pipe, cable, and wire. The term "underground facilities" generally refers to the buried pipelines and cables that transport petroleum, natural gas, electricity, communications, cable television, steam, water, and sewer. In addition to being categorized by product type and structural component, underground networks are further grouped according to function (gathering, transmission, distribution, service lines); owner (public utility or private industry); or jurisdiction (municipalities, State, and Federal agencies). The diverse and segmented nature of underground facilities is evident from the variety of organizational interests that work with the subsurface infrastructure: facility owners; construction crews, government authorities, insurance companies, locating contractors, and notification communication specialists.
The Safety Board has long been concerned about the number of excavationcaused pipeline accidents. In response to six serious pipeline accidents during 1993 and 1994 that were caused by excavation damage and to foster improvements in State excavation damage prevention programs, the Safety Board and RSPA jointly sponsored a workshop in September 1994. This workshop brought together about 400 representatives from pipeline operators, excavators, trade associations, and local, State, and Federal government agencies to identify and recommend ways to improve prevention programs.
This safety study was initiated to analyze the findings of the 1994 workshop, to discuss industry and government actions undertaken since the workshop, and to formalize recommendations aimed at further advancing improvements in excavation damage prevention programs. Safety issues discussed in the study include the following:
As a result of this study, safety recommendations were issued to the Research and Special Programs Administration, the American Public Works Association, the Federal Highway Administration, the Association of American Railroads, the American Short Line Railroad Association, the American Society of Civil Engineers, and the Associated General Contractors of America.
As a result of this safety study, the National Transportation Safety Board made the following recommendations:
To the Research and Special Programs Administration
Conduct at regular intervals joint government and industry workshops on excavation damage prevention that highlight specific safety issues, such as full participation, enforcement, good marking practices, the importance of mapping, and emergency response planning. (P-97-14)
Initiate and periodically conduct, in conjunction with the American Public Works Association, detailed and comprehensive reviews and evaluations of existing State excavation damage prevention programs and recommend changes and improvements, where warranted, such as full participation, administrative enforcement of the program, pre-marking requirements, and training requirements for all personnel involved in excavation activity. (P-97-15)
Sponsor independent testing of locator equipment performance under a variety of field conditions. (P-97-16)
As a result of the testing outlined in Safety Recommendation P-97-16, develop uniform certification criteria of locator equipment. (P-97-17)
Once locator equipment performance has been evaluated and defined by certification criteria as outlined in Safety Recommendation P-97-17, review State requirements for location accuracy and hand-dig tolerance zones to determine that they can be accomplished with commercially available technology. (P-97-18)
Develop mapping standards for a common mapping system, with a goal to actively promote its widespread use. (P-97-19)
Develop and distribute to pipeline operators written guidance to improve the accuracy of information for reportable accidents, including parameters for estimating property damage resulting from an accident. (P-97-20)
As part of the comprehensive plan for the collection and use of gas and hazardous liquid data, revise the cause categories on the accident report forms to eliminate overlapping and confusing categories and to clearly list excavation damage as one of the data elements, and consider developing categories that address the purpose of the excavation. (P-97-21)
In conjunction with the American Public Works Association, develop a plan for collecting excavation damage exposure data. (P-97-22)
Work with the one-call systems to implement the plan outlined in Safety Recommendation P-97-22 to ensure that excavation damage exposure data are being consistently collected. (P-97-23)
Use excavation damage exposure data outlined in Safety Recommendation P-97-22 in the periodic assessments of the effectiveness of State excavation damage prevention programs described in Safety Recommendation P-97-15. (P-97-24)
To the American Public Works Association
Initiate and periodically conduct, in conjunction with the Research and Special Programs Administration, detailed and comprehensive reviews and evaluations of existing State excavation damage prevention programs and recommend changes and improvements, where warranted, such as full participation, administrative enforcement of the program, pre-marking requirements, and training requirements for all personnel involved in excavation activity. (P-97-25)
In conjunction with the Research and Special Programs Administration, develop a plan for collecting excavation damage exposure data. (P-97-26)
Work with the one-call systems to implement the plan outlined in Safety Recommendation P-97-26 to ensure that excavation damage exposure data are being consistently collected. (P-97-27)
Use excavation damage exposure data outlined in Safety Recommendation P-97-26 in the periodic assessments of the effectiveness of State excavation damage prevention programs described in Safety Recommendation P-97-25. (P-97-28)
Review existing training programs and materials related to excavation damage prevention and develop guidelines and materials for distribution to one-call notification centers. (P-97-29)
Develop guidelines and materials that address initial emergency actions by excavators when buried facilities are damaged and then distribute this information to all one-call notification centers. (P-97-30)
Encourage one-call notification centers to work with their members to provide facility location information for the purpose of construction planning. (P-97-31)
Develop standards, in conjunction with the American Society of Civil Engineers, for map depiction of underground facilities that were installed using directional boring techniques. (P-97-32)
Address, in conjunction with the American Society of Civil Engineers, the accuracy of information that depicts subsurface facility locations on construction drawings. (P-97-33)
To the Federal Highway Administration
Require State transportation departments to participate in excavation damage prevention programs and consider withholding funds to States if they do not fully participate in these programs. (P-97-34)
To the Association of American Railroads
Urge your members to fully participate in statewide excavation damage prevention programs, including one-call notification centers. (P-97-35)
To the American Short Line Railroad Association
Urge your members to fully participate in statewide excavation damage prevention programs, including one-call notification centers. (P-97-36)
To the American Society of Civil Engineers
Develop standards, in conjunction with the American Public Works Association, for map depiction of underground facilities that were installed using directional boring techniques. (P-97-37)
Address, in conjunction with the American Public Works Association, the accuracy of information that depicts subsurface facility locations on construction drawings. (P-97-38)
To the Associated General Contractors of America
Promote the use of subsurface utility engineering practices among your members to minimize conflicts between construction activities and underground systems. (P-97-39)
