PB97-917003

NTSB/SS-97/0l

NATIONAL

TRANSPORTATION

SAFETY

BOARD

WASHINGTON, D.C. 20594

SAFETY STUDY

PROTECTING

EXCAVATION

PUBLIC SAFETY THROUGH

DAMAGE PREVENTION

6931
National Transportation Safety Board. 1997. Protecting Public Safety Through Excavation

Damage Prevention. Safety Study NTSB/SS-97/01. Washington, DC. 106 p.

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. In 1994, the Safety Board and the Research and

Special Programs Administration jointly sponsored a workshop that brought together industry

representatives to identify and recommend ways to improve State excavation damage

prevention programs. The Board conducted the current safety study 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. The safety issues discussed in the report include (a)

the essential elements of an effective excavation damage prevention program; (b) the

accuracy of information regarding buried facilities; and (c) system measures, reporting

requirements, and data collection. Safety recommendations concerning these issues were

made to the Research and Special Programs Administration, the Federal Highway

Administration, the American Public Works Association, the Association of American

Railroads, the American Short Line Railroad Association, the American Society of Civil

Engineers, and the Associated General Contractors of America.

The National Transportation Safety Board is an independent Federal agency dedicated to promoting aviation, railroad, highway, marine, pipeline, and hazardous materials safety. Established in 1967, the agency is mandated by

Congress through the Independent Safety Board Act of 1974 to investigate transportation accidents, determine the

probable causes of the accidents, issue safety recommendations, study transportation safety issues, and evaluate the

safety effectiveness of government agencies involved in transportation. The Safety Board makes public its actions

and decisions through accident reports, safety studies, special investigation reports, safety recommendations, and

statistical reviews.

Information about available publications may be obtained by contacting:

National Transportation Safety Board

Public Inquiries Section, RE-51

490 L’Enfant Plaza, S.W.

Washington, D.C. 20594

(202)314-6551

Safety Board publications may be purchased, by individual copy or by subscription, from the National Technical

Information Service. To purchase this publication, order report number PB97-917003 from:

National Technical Information Service

5285 Port Royal Road

Springfield, Virginia 22161

(703)605-6000
Protecting Public Safety Through

Excavation Damage Prevention

Safety Study

NTSB/SS-97/01

PB97-917003

Notation 6931

December 1997

National Transportation Safety Board

490 L’Enfant Plaza, S.W.

Washington, D.C. 20594

Contents iii

Contents

Executive Summary .............................................................................................................................. v

Chapter 1: Introduction...................................................................................................................... 1

Chapter 2: Overview of Subsurface Infrastructure

and Regulatory and Legislative Initiatives................................................................................... 5

Subsurface Infrastructure ................................................................................................................................ 5

Regulatory and Legislative Initiatives............................................................................................................. 7

Chapter 3: Damage Prevention Practices.................................................................................. 11

Mandatory Participation ............................................................................................................................... 11

One-Call Notification System....................................................................................................................... 18

Function and Structure of the Centers .................................................................................................. 18

Methods of Operation .......................................................................................................................... 19

Excavation Notification Tickets........................................................................................................... 20

Effective Sanctions ....................................................................................................................................... 21

Excavation Marking...................................................................................................................................... 24

Pre-Marking ......................................................................................................................................... 25

Marking Standards ............................................................................................................................... 25

Employee Qualifications and Training ......................................................................................................... 26

Training and Educating Excavation Personnel..................................................................................... 26

Emergency Response Planning ............................................................................................................ 30

Discussion..................................................................................................................................................... 31

Chapter 4: Accuracy of Information Regarding Buried Facilities.................................. 33

Underground Detection Technologies .......................................................................................................... 33

Vertical/Depth Location ............................................................................................................................... 35

Directional Boring/Trenchless Technology .................................................................................................. 36

Mapping........................................................................................................................................................ 38

Subsurface Utility Engineering ..................................................................................................................... 41

Chapter 5: System Performance Measures............................................................................... 45

Risk Exposure............................................................................................................................................... 45

Accident Reporting Requirements of RSPA................................................................................................. 47

Accident Causes............................................................................................................................................ 49

Conclusions............................................................................................................................................. 55

Recommendations................................................................................................................................. 57
iv Contents

Appendixes .............................................................................................................................................. 63

A: NTSB Investigations of Accidents Caused by Excavation Damage, Since 1985 ................................. 63

B: Excerpts From Federal Regulations Pertaining to Excavation.............................................................. 64

C: Characteristics of Current State Laws on Excavation Damage Prevention........................................... 67

D: Reports of Workshop Groups on Excavation Damage Prevention....................................................... 81

E: Example of Universal Damage Report Form........................................................................................ 91

F: Industry Practices and Procedures for Excavation Damage Prevention ............................................... 93

G: NTSB Safety Recommendations Related to RSPA Accident Data..................................................... 104

Acronyms Used in the Report

AGA American Gas Association

AGCA Associated General Contractors of America

AOPL Association of Oil Pipe Lines

APGA American Public Gas Association

API American Petroleum Institute

APWA American Public Works Association

ASCE American Society of Civil Engineers

ASLRA American Short Line Railroad Association

CFR Code of Federal Regulations

DOT U.S. Department of Transportation

DPU Department of Public Utilities

FAA Federal Aviation Administration

FHWA Federal Highway Administration

GPS global positioning system

GRI Gas Research Institute

INGAA Interstate Natural Gas Association of America

MnOPS Minnesota Office of Pipeline Safety

NARUC National Association of Regulatory Utility Commissioners

NPRM Notice of Proposed Rulemaking

NRSC Network Reliability Steering Committee

NULCA National Utility Locating Contractors Association

OCSI One-Call Systems International

OPS Office of Pipeline Safety

OPSO Office of Pipeline Safety Operations

OSHA Occupational Safety and Health Administration

RSPA Research and Special Programs Administration

SUE Subsurface utility engineering

TIGER topographically integrated geographic encoding and referencing

ULCC Utility Location and Coordinating Council
Executive Summary v

Executive Summary

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
vi Executive Summary

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:

• essential elements of an effective excavation damage prevention program;

• accuracy of information regarding buried facilities; and

• system measures, reporting requirements, and data collection.

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.
Chapter 1 Introduction 1

Chapter 1

Introduction

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. In March 1994, a pipeline accident in

Edison, New Jersey, injured 112 persons, destroyed eight buildings, and resulted in the

evacuation of 1,500 apartment residents.1 Accident damage exceeded $25 million. The

National Transportation Safety Board’s investigation determined that the probable cause

of the accident was excavation damage to the exterior of a 36-inch gas pipe. Less than 3

months later, a gas explosion in Allentown, Pennsylvania, resulted in 1 fatality, 66 injuries, and more than $5 million in property damage.2

 The Safety Board concluded that the

accident was caused by a service line that had been exposed during excavation and had

subsequently separated at a compression coupling.

A propane gas explosion on November 21, 1996, in the Rio Piedras shopping district of San Juan, Puerto Rico, resulted in 33 fatalities and 69 injuries. This accident, one

of the deadliest in pipeline history, made 1996 a record year for pipeline fatalities. The

San Juan accident accounted for more fatalities than occurred the entire previous year,

and it vividly illustrates the tragic potential of a single excavation-damaged pipe.

The Safety Board determined that the probable cause of the propane gas

explosion, fueled by an excavation-caused gas leak in the basement of the Humberto

Vidal, Inc., office building, was the failure of San Juan Gas Company, Inc., to oversee its

employees’ actions to ensure timely identification and correction of unsafe conditions and

strict adherence to operating practices; and to provide adequate training to employees.3

Also contributing to the explosion was the failure of the Research and Special Programs

Administration/Office of Pipeline Safety to effectively oversee the pipeline safety

program in Puerto Rico; the failure of the Puerto Rico Public Service Commission to

 1

 National Transportation Safety Board. 1995. Texas Eastern Transmission Corporation Natural Gas

Pipeline Explosion and Fire; Edison, New Jersey; March 23, 1994. Pipeline Accident Report NTSB/PAR95/01. Washington, DC. 104 p.

2

 National Transportation Safety Board. 1996. UGI Utilities, Inc., Natural Gas Distribution Pipeline

Explosion and Fire; Allentown, Pennsylvania; June 9, 1994. Pipeline Accident Report NTSB/PAR-96/01.

Washington, DC. 94 p.

3

 National Transportation Safety Board. 1997. San Juan Gas Company, Inc./Enron Corp. Propane Gas

Explosion in San Juan, Puerto Rico, on November 21, 1996. Pipeline Accident Report NTSB/PAR-97/01.

Washington, DC.
2 Chapter 1 Introduction

require San Juan Gas Company, Inc., to correct identified safety deficiencies; and the

failure of Enron Corporation to adequately oversee the operation of San Juan Gas

Company, Inc. Contributing to the loss of life was the failure of San Juan Gas Company,

Inc., to adequately inform citizens and businesses of the dangers of propane gas and the

safety steps to take when a gas leak is suspected or detected.

In 1994, a tragic pipeline accident occurred in Caracas, Venezuela. A 22-ton

trenching device, working on a road construction project, struck a 10-inch gas transmission line. An occupied bus and cars stopped by the road construction were engulfed in

flames. Fifty-one persons were killed and 34 injured. The next year, in April 1995, construction work on a subway system in Taegu, Korea, ruptured a gas line, killing 103 persons. These accidents occurred in systems that do not operate under U.S. regulations, but

they illustrate the catastrophic consequences that can result from excavation damage to

underground facilities.4

Excavation and construction activities are the largest single cause of accidents to

pipelines. Data maintained by the U.S. Department of Transportation (DOT), Research

and Special Programs Administration (RSPA), Office of Pipeline Safety (OPS), 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.5 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 pipeline accidents in

other countries.6

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 NRSC, show that more than half of all facility outages are the

result of excavation damage (53 percent), and in more than half of those cases (51

percent), the excavator failed to notify the facility owner or provided inadequate

notification.7 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

 4

 The National Transportation Safety Board does not have the authority to investigate pipeline

accidents in other countries.

5

 Transportation Research Board, National Research Council. 1988. Pipelines and Public Safety.

Special Report 219. Washington, DC.

6

 Dipl.-Ing, Klees Alfred; Wasserfaches, e.V. 1997. The Safety Concept of Public Gas Supply in

Germany. In: Proceedings, 20th IGU World Gas Conference; Copenhagen.

7

 Alliance for Telecommunications Industry Solutions/Network Reliability Steering Committee. 1996.

Results and Recommendations Pertaining to Facilities Reliability. Facilities Solutions Report. Washington,

DC. February.
Chapter 1 Introduction 3

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.8

 For 1995, the FAA’s National Maintenance

Control Center documented cable cuts that affected 32 air traffic control facilities, including five en route control centers. Cable cuts for the first 8 months of 1997 affected

air traffic control operations for a total of 158 hours.9

The Safety Board has long been concerned about the number of excavationcaused pipeline accidents. Because of several excavation-caused pipeline accidents that

occurred between 1968 and 1972,10 the Safety Board sponsored a symposium on pipeline

damage prevention. Many of the proposals developed at that April 1972 symposium led

to a Safety Board special study on damage prevention11 and recommendations that resulted in many of the concepts and systems that have now been implemented to minimize

excavation-caused damage to pipelines; for example, the local utility location and coordinating councils (ULCCs) established by the American Public Works Association

(APWA). Since that symposium, the Safety Board has continued to support the initiatives of the APWA, the States, and the national organizations to reduce excavation damage to pipelines. The Safety Board has been an advocate of strong damage prevention

programs through its recommendation process and through testimony before Congress

and State legislatures, and before groups and trade associations interested in pipeline

safety, such as the Interstate Natural Gas Association of America (INGAA), the American

Public Gas Association (APGA), the Association of Oil Pipe Lines (AOPL), the American Gas Association (AGA), and the American Petroleum Institute (API).

The combined efforts of industry, the States, the Safety Board, and other Federal

agencies led to a decrease in the number of accidents during the 1980s. Nevertheless,

excavation-caused damage remains the largest single cause of pipeline accidents.

Appendix A lists excavation-caused accidents investigated by the Safety Board since

1985. The Board is currently investigating three other accidents that involved excavation:

Gramercy, Louisiana; Tiger Pass, Louisiana; and Indianapolis, Indiana.12

 8

 Federal Aviation Administration, Safety and Quality Assurance Division, Associate Administrator for

Aviation Safety. 1993. Cable Cuts: Causes, Impacts, and Preventive Measures. Special Review.

Washington, DC. 30 p.

9

 Federal Aviation Administration, National Maintenance Control Center AOP-100. 1997. Adhoc Report of facility/service outages associated with cable cuts, 7/1/95–8/22/97.

10 A gas explosion in Annandale, Virginia, on March 24, 1972, occurred just 1 month before the

symposium.

11 National Transportation Safety Board. 1973. Prevention of Damage to Pipelines. Special Study

NTSB/PSS-73/01. Washington, DC.

12 NTSB accident Nos. DCA96FP004 (Gramercy, Louisiana; May 24, 1996); DCA97FP001 (Tiger

Pass, Louisiana; October 23, 1996); and DCA97FP005 (Indianapolis, Indiana; July 21, 1997).
4 Chapter 1 Introduction

In response to six serious pipeline accidents during 1993 and 1994 that were

caused by excavation damage13 and to foster improvements in State excavation damage

prevention programs, the Safety Board and RSPA jointly sponsored a workshop in

September 1994.14 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.

On May 20, 1997, the Safety Board updated its “Most Wanted” list of safety

improvements to include excavation damage prevention.15 The Board’s recommendations on this issue address requirements for excavation damage prevention

programs; comprehensive education and training for operators of buried facilities and the

public; and effective government monitoring and enforcement.

This safety study, “Protecting Public Safety Through Excavation Damage

Prevention,” 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. Chapter 2 of the study provides some background information on the

subsurface infrastructure and an overview of pertinent regulatory and legislative

initiatives. Chapter 3 discusses the various components of a damage prevention program,

Chapter 4 discusses the accuracy of information regarding buried facilities, Chapter 5

addresses system performance measures, and the last sections contain the Safety Board’s

conclusions and recommendations.

 13 The accidents occurred at Allentown, Pennsylvania; Edison, New Jersey; Green River, Wyoming; St.

Paul, Minnesota; Cliffwood Beach, New Jersey; and Reston, Virginia.

14 National Transportation Safety Board. 1995. Proceedings of the Excavation Damage Prevention

Workshop; September 8–9, 1994; Washington, DC. Report of Proceedings NTSB/RP-95/01. Washington,

DC.

15 In October 1990, the Safety Board adopted a program to identify the “Most Wanted” safety improvements. The purpose of the Board’s “Most Wanted” list, which is drawn up from safety recommendations previously issued, is to bring special emphasis to the safety issues the Board deems most critical.
Chapter 2 Infrastructure and Initiatives 5

Chapter 2

Overview of Subsurface

Infrastructure and Regulatory

and Legislative Initiatives

Subsurface Infrastructure

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. These subsurface networks are constructed of cast iron, steel,

fiberglass, copper wire, concrete, clay, plastic, or optical fiber depending on the age of the

system and its product content. In addition to being categorized by product type and

structural components, 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 U.S. underground infrastructure comprises about 20 million miles (32.2 million kilometers) of pipe,

cable, and wire.16

Pipeline regulation and oversight by DOT distinguishes between the transport of

carbon dioxide, hazardous liquids, and gas. Hazardous liquid lines carry petroleum, petroleum products, or anhydrous ammonia. Their functions include gathering lines that

transport petroleum from a field production facility to the primary pumping stations.

Trunk lines differentiate a line-haul function for the transport of crude oil to refineries

and product from the refineries. Gas lines are categorized as gathering, transmission, or

distribution. Gathering lines transport gas from a current production facility to a transmission line or processing facility; transmission lines transport gas to distribution centers,

storage facilities, or large volume customers; and distribution service lines transport gas

to end users.17

 16 Estimates of the total infrastructure size are difficult to verify. Bell Communications Research used

20 million miles during the Safety Board’s 1994 excavation damage prevention workshop.

17 Wright, P.H.; Ashford, N.J. 1989. Transportation Engineering: Planning and Design. 3d ed. New

York: Wiley & Sons ( p. 25). 776 p.
6 Chapter 2 Infrastructure and Initiatives

The diverse and segmented nature of underground facilities is evident from the

variety of organizational interests that work with the subsurface infrastructure:

• Facility owners design, install, and maintain the underground network.

Owners are a diverse group with varied interests; they include private

corporations, municipal public works systems, private and public utility

companies, telecommunication providers, and State transportation traffic

control systems.

• Construction crews engage in excavation activities for a variety of reasons,

and they use an assortment of government permits. Excavation activities are

carried out by building trades, farmers, homeowners, State and local

transportation departments, and others.

• States regulate actions to protect safety.

• Insurance companies insure the underground facilities, property, and

construction business activities.

• Locators work at excavation sites to identify and mark underground facilities.

This work may be conducted by the operators of the underground facility or

by locating contractors who specialize in providing underground locating

services.

• One-call communication centers coordinate notifications about digging

activities. These centers may be an operating unit of a facility owner or they

may be independent entities that provide notification service to several

facility owners.

The number of times people dig into the underground infrastructure illustrates the

sheer frequency of excavation: there were an estimated 13 million excavation notices issued to utility operators across the United States in 1996, though the actual number is

higher because some excavators do not use one-call notification services.18

Urbanization of lands through which utility lines are routed, combined with an increase in the number of users of the underground, has created competition for the

underground space. A recent study by the American Farmland Trust states that the rate of

farmland lost to development is 2 acres per minute, or 1 million acres per year (0.81

hectare per minute, or 405 000 hectares per year).19 Increased construction activity,

which results in increased excavation, is directly related to population growth, demographic shifts, and a growing national economy. New building construction requires that

additional services—more utility lines and communication services—be placed in the

 18 The estimated number of excavations is based on the number of notifications received in 1996 by

member organizations of One-Call Systems International.

19 American Farmland Trust. 1997. Farming on the Edge. Washington, DC.
Chapter 2 Infrastructure and Initiatives 7

underground. There is also a trend in current suburban development to remove

aboveground utilities to reduce clutter and storm damage. Additions to the underground

infrastructure are installed within the underground space occupied by the existing

systems. Thus, increased construction can be considered a corollary of increased excavation. This relationship affects the approach to excavation damage prevention because

the desire to avoid damage is a genuine interest of everyone, but the success of damage

prevention depends on systematic safeguards.

Regulatory and Legislative Initiatives

Underground facilities and pipelines are addressed by various Federal regulations.

The Federal regulations issued by RSPA are contained in Title 49 Code of Federal

Regulations (49 CFR) Parts 190-199. Parts 191 and 192 address natural gas regulations;

Part 195 covers hazardous liquids and carbon dioxide; and Part 198 prescribes regulations

for grants to aid State safety programs. Federal regulations establishing minimum

standards for excavation damage prevention programs for gas pipeline operators (49 CFR

192.614)20 were extended to the operators of hazardous liquid pipelines (49 CFR

195.442) effective April 1995.21 (Excerpts from these regulations are reproduced in

appendix B.)

Federal regulations mandate companies to develop and participate in damage prevention programs when those companies transport gas and hazardous liquids subject to

DOT jurisdiction.22 Participation in a one-call notification system satisfies parts of this

requirement; consequently, one-call centers have become a key element in damage prevention programs. As the Safety Board’s accident investigations and 1994 workshop

have pointed out, however, one-call notification programs do not ensure damage prevention. Protection from excavation damage will occur only when facility owners, excavators, locators, and one-call operators—people working with the underground facilities—

share responsibilities to protect underground facilities from excavation damage. (These

responsibilities are discussed in the next two chapters.)

 20 In September 1988, RSPA’s Technical Pipeline Safety Standards Committee unanimously supported

extending Section 192.614 to cover onshore gas pipelines in Class 1 and 2 locations.

21 RSPA published the final rule, “Excavation Damage Prevention Programs for Gas and Hazardous

Liquid and Carbon Dioxide Pipelines,” in the Federal Register on March 20, 1995.

22 49 CFR Parts 192.614 and 195.442.
8 Chapter 2 Infrastructure and Initiatives

Both government and industry have, in the past, prepared model statutes that

would serve as a framework for individual State legislation of damage prevention programs. The Office of Pipeline Safety Operations (OPSO) prepared model statutes in

1974 and 1977 and encouraged State and local governments to enact model legislation.23

The APWA prepared guidelines for damage prevention laws that were not substantially

different from the OPSO model. The AGA also developed elements for damage prevention legislation; these elements were documented in a 1988 report issued by the Transportation Research Board.24 Several features of the OPSO model statute overlapped with

features in regulations issued by the Occupational Safety and Health Administration

(OSHA) of the Department of Labor.

OSHA regulations require excavators to notify utility owners of planned excavation and to request that the estimated location of underground facilities be marked prior to

the start of excavation (29 CFR 1926.651(b)). The regulations also require excavators to

determine the exact location “by safe and acceptable means” when they approach the estimated location during excavation.25 (Excerpts of the OSHA regulations are included in

appendix B of this report.)

Model legislation was introduced in the 103d

 Congress following the 1994 accident in Edison, New Jersey.26 That bill, which strongly recommended rather than mandated State participation in one-call systems, passed the House of Representatives but not

the U.S. Senate. A different version of the bill (HR431/S164) was introduced in, but not

adopted by the 104th Congress. Industry representatives worked with the 105th Congress

to again develop legislation. The Comprehensive One-Call Notification Act of 1997

(S1115) was introduced into the Senate in July 1997, and the Surface Transportation

Safety Act of 1997 (HR1720) was introduced into the House in May 1997. The Senate

Committee on Commerce, Science, and Transportation held a public hearing on S1115 in

September 1997; the Senate passed the measure on November 9, 1997. The issues related

to the currently proposed legislation are not substantially different from earlier versions; a

comparison of the features indicates the following:

 23 Courtney, W.J.; Kalkbrenner, D.; Yie, G. 1977. Effectiveness of Programs for Prevention of Damage

to Pipelines by Outside Forces. Final Report DOT/NTB/OPSO-77/12. Washington, DC: U.S. Department

of Transportation, Materials Transportation Bureau, Office of Pipeline Safety Operations; contract DOTOS-60521. 290 p. (The Office of Pipeline Safety Operations later became the Office of Pipeline Safety

within the DOT’s Research and Special Programs Administration.)

24 Transportation Research Board, National Research Council. 1988. Pipelines and Public Safety.

Special Report 219. Washington, DC.

25 The Safety Board’s 1973 review of OSHA regulations is contained in its special report entitled “Prevention of Damage to Pipelines” (NTSB/PSS-73/01).

26 National Transportation Safety Board. 1995. Texas Eastern Transmission Corporation Natural Gas

Pipeline Explosion and Fire; Edison, New Jersey; March 23, 1994. Pipeline Accident Report NTSB/PAR95/01. Washington, DC. 104 p.
Chapter 2 Infrastructure and Initiatives 9

• The current bills are advisory in nature rather than prescriptive.

• The House bill recommends participation by all facility owners and

excavators; the Senate bill recommends appropriate participation by

underground facility operators and excavators. Both contain incentives for

compliance based on providing grant monies for State use.

• Both bills recommend general components to be included in the State

programs; the House bill calls these elements, the Senate bill calls them

minimum standards. There is no specific guidance for States concerning the

organizational structure and funding mechanisms of one-call centers, or the

administration of enforcement provisions.

• Both bills include a mechanism for recommending effective damage

prevention practices; specifically, the Secretary of Transportation shall study

existing one-call systems to determine practices that are most effective in

preventing excavation damage.

The recently introduced legislation makes no specific requirements on the States

because the Federal government has not exercised jurisdiction over one-call operations,

and because States cannot be required to pass legislation. This has led one industry trade

publication to characterize both bills as “toothless in terms of being able to require states,

excavators, facility operators, or one-call centers” to modify existing practices to achieve

the objectives set forth in the legislation.27 Table 2–1 shows a comparison of the two

bills that appeared in a recent trade association newsletter. The Safety Board’s position

regarding certain provisions of the proposed legislation is discussed in the next chapter.

 27 The Conduit 3(4): 1, 4. August 1997. Spooner, WI: National Utility Locating Contractors

Association.
10 Chapter 2 Infrastructure and Initiatives

Table 2–1. Comparison by a trade association newsletter of the currently

proposed Federal legislation for one-call systems.

House Bill HR1720 Senate Bill S1115(a)

1. Shall consider the establishment of a

nationwide toll-free telephone number

system.

2. Elements of a State program shall include:

(a) All excavators and facility operators;

(b) 24-hour coverage for emergency notice;

(c) Public education about the program;

(d) Proper excavation procedures training;

(e) Excavators must contact the One-Call

Center;

(f) Facility operators must mark their facilites;

(g) Effective enforcement;

(h) Fair free schedule for operating the State

program.

3. Funding of $1M in fiscal year 1998, “as

necessary” in FY 1999, and 2000 to be used

for improving damage prevention. Money to

come from fees collected from pipeline

operators.

4. Secretary of Transportation to develop a

model program in consultation with all

affected parties, conduct workshops and

public education.

1. (Telephone number language deleted

because OCSI already has a system in

operation.)

2. Minimum standards of a State program to

include:

(a) appropriate participation by excavators

and facility operators considering risks, cost:

benefit ratios, and allowing voluntary

participation where risk is low;

(b) Administrative system of variable

penalties.

3. Funding of:

(a) grants of $1M in FY 1999 and $5 M in FY

2000 to be available until expended;

(b) funds “as necessary” in FY 1998–2000 for

administration. Money to come from general

revenues.

States would get money when the Secretary

of Transportation has determined, from a

grant application, that the State is in

compliance with the minimum program

standards.

4. Secretary to review the one-call system “best

practices” and issue a report.

(a) The U.S. Senate passed S1115 on November 9, 1997.

Source: The Conduit 3(4): 1, 4. August 1997. Spooner, WI: National Utility Locating Contractors Association. (The

full text of the bills is available on the Internet at www.underspace.com.)
Chapter 3 Damage Prevention Practices 11

Chapter 3

Damage Prevention Practices

In its report of the accident in Allentown, Pennsylvania, on June 9, 1994,28 the

Safety Board highlighted the common elements of effective State excavation damage

prevention programs that have been recognized in the industry and that were discussed in

detail at the Safety Board’s 1994 workshop. The elements include (1) mandatory

participation by all affected parties, whether private or public; (2) a true one-call

notification system in which excavators can alert all operators of buried systems; (3)

swift, effective sanctions against violators of State damage prevention laws; and (4) an

effective education program for the public, contractors, excavation machine operators,

and operators of underground systems that stresses the importance of notifying before

excavating, accurately marking buried facilities, and protecting marked facilities when

excavating. Other elements that have been deemed critical to an effective damage

prevention program and that have been the subject of past Safety Board recommendations

include accurate mapping, employee training, and emergency response planning. This

chapter discusses the various aspects of these elements and summarizes the reports and

conclusions of the 1994 workshop participants as they relate to these elements.

Mandatory Participation

Every State except Hawaii and the District of Columbia has a damage prevention

law to govern the activities of operators and excavators of most buried facilities. Texas,

the most recent State to enact legislation, passed the Underground Facility Damage Prevention and Safety Act in June 1997 to establish a non-profit corporation to oversee the

State’s three one-call systems. The Governor of Puerto Rico is preparing damage prevention legislation for introduction in the Legislative Assembly. In the interim, he has

issued an Executive Order that establishes an excavations notice center, requires government facility operators to use the center, and encourages its use by private entities.

Individual States have developed a variety of program approaches to handling the

problem of excavation damage of underground facilities. A key finding in a 1995 OPS

study was that there were “significant variations among state statutes, among excavators,

 28 National Transportation Safety Board. 1996. UGI Utilities, Inc., Natural Gas Distribution Pipeline

Explosion and Fire; Allentown, Pennsylvania; June 9, 1994. Pipeline Accident Report NTSB/PAR-96/01

(Appendix E, “Gas Piping Technical Committee Excavation Damage Prevention Guidelines”). 94 p.
12 Chapter 3 Damage Prevention Practices

and among facility operators in the ways that excavation around underground facilities is

done.”29 Table 3–1 provides an overview of the variations among State programs;

appendix C provides a broader look at aspects of the States’ programs.

More than half the States (30) have mandatory one-call participation programs

and most (39) are intended to protect all utilities. However, all but seven States

(Connecticut, Iowa, Massachusetts, Maryland, Maine, New Hampshire, and Vermont)

have granted exemptions to a variety of organizations. State laws specifically qualify

their exemptions, but, in general, exempt organizations are not required to participate in

the State’s excavation damage prevention program. Exemptions have been granted to

State transportation departments, railroads, mining operations, city/State/Federal

governments, cemeteries, water utilities, military bases, and Native American Lands. Although underground facilities frequently follow road rights-of-way, nine States have

current damage prevention legislation that specifically exempts State transportation departments; another dozen States exempt substantial State highway maintenance activities.

State highway administrators have argued that they do not have the resources for

participating in notification and marking. Several States (Arizona, Arkansas, Delaware,

Oregon, Mississippi, and Washington) exempt agricultural activities, home owners, and

tilling operations less than 12 inches (30.5 centimeters) deep. By receiving exemptions,

these entities are not required to inform utilities or underground facility owners of their

digging activities, nor are the underground facilities operated by these exempt entities

marked or protected in advance of scheduled excavations.

In the 1994 Green River, Wyoming, accident investigated by the Safety Board, a

highway contractor operating excavation equipment struck a 10-inch-diameter natural gas

gathering line.30 The accident resulted in three fatalities. The pipeline operator did not

participate in the local excavation notification one-call program, though the operator was

required by the State of Wyoming to belong to the one-call system. The highway contractor notified the one-call center prior to excavation but did not notify one-call concerning project modifications that expanded the geographic area of work. Neither the

Wyoming Department of Transportation nor its contractor made telephone notification

directly to the pipeline operator. Had these parties participated in the one-call notification

program, the gas line would have been marked and the accident likely would not have

happened.

 29 U.S. Department of Transportation, Office of Pipeline Safety. 1995. Exemplary Practices and Success Stories In One-Call Systems. Washington, DC. May.

30 National Transportation Safety Board Accident Brief DCA94MP002; Green River, Wyoming;

May 3, 1994.
Chapter 3 Damage Prevention Practices 13
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Chapter 3 Damage Prevention Practices 17

In April 1996, excavation damage of a water main in Buffalo, New York, flooded

the downtown area. The municipal water department was not a member of the local onecall system. In fact, at that time four separate city utilities in Buffalo had to be notified to

coordinate excavation work; none of those utilities participated in the local one-call system. This situation existed even though State law required participation and made it free

for municipalities.

Panelists at the 1994 damage prevention workshop agreed that all owners/

operators of buried facilities should participate in damage prevention programs; there

should be no exceptions. Some States have realized the value of full participation and

have taken legislative action to ensure participation. For example, according to Pennsylvania law, underground facility owners who are not one-call members cannot collect

damage costs from excavators who hit their lines. A similar requirement became

effective in Florida in October 1997. Oregon has mandatory one-call membership

provisions for all facility owners with lines that cross public rights-of-way.31

The Safety Board agrees that the failure of all parties to participate in damage prevention programs can substantially undermine the effectiveness of the programs. When

parties such as State transportation departments and railroads are given exemptions to

participation in excavation damage prevention programs, these parties, in essence, are no

longer obligated to use one-call notification centers to protect their facilities or to protect

the facilities of others that use their rights-of-way. Nor are they obligated to inform other

parties of their intent to dig or excavate. In addition to public safety interests, the Board

is concerned that taxpayers ultimately bear the burden for these exemptions by paying for

the cost of fixing excavation damage, particularly damage caused by State agencies that

are not protecting their facilities. The Safety Board concludes that full participation in

excavation damage prevention programs by all excavators and underground facility owners is essential to achieve optimum effectiveness of these programs.

Because of the number of State transportation department activities that are exempt from participating in excavation damage prevention programs, the Safety Board believes that the Federal Highway Administration should 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.

Although railroad rights-of-way are not as prevalent as those of highways, they

frequently serve as ideal routes for underground facilities, particularly for gas and oil

transmission lines. Contractual provisions for underground facilities to use railroad

rights-of-way are a revenue source for the railroads. However, railroads are also exempt

from participating in some State excavation damage prevention programs. For the larger,

Class 1 railroads, there are usually internal operating procedures for notification of

 31 Underspace Bulletin 3(9): 2. June 1997. Spooner, WI: Center for Subsurface Strategic Action

(CSSA).
18 Chapter 3 Damage Prevention Practices

excavation work on railroad property. However, recent trends in contracting out construction and maintenance services suggest that not all work is controlled through internal

operations. Additionally, the number of small, short line railroad companies is

increasing. The Association of American Railroads estimates that there are 450–475

short line railroads; 424 are members of the American Short Line Railroad Association

(ASLRA). ASLRA membership has doubled in the past 25 years. These smaller companies often do not have the resources to operate internal excavation notification systems.

Consequently, the Safety Board believes that the Association of American Railroads and

the American Short Line Railroad Association should urge their members to fully participate in statewide excavation damage prevention programs, including one-call

notification centers.

One-Call Notification System

Function and Structure of the Centers.—A cornerstone of current damage prevention programs involves the use of one-call notification centers. One-call notification

centers function as communication systems established by two or more utilities, government agencies, or other operators of underground facilities to provide one telephone

number for notification of excavating, tunneling, demolition, or any other similar work.32

The system is designed so that excavation contractors, other facility owners, or the general public can notify the one-call center of the location of intended digging or construction activity. The intended area of excavation may be pre-marked, generally with white

spray paint, to specifically indicate the digging or construction area.33 Based on that one

call, the center, in turn, notifies its members that digging or construction will occur in a

given location. The facility owners, or their contract locator service, go to the excavation

site and mark the location of any of their underground facilities in that area. By avoiding

the use of power-driven tools in the vicinity of marked facilities, there is a decreased risk

of damage to underground facilities.

Notification services use a variety of names and logos to create meaningful associations in the public’s mind: Miss Dig System in Michigan, Underground Service Alert

in California, Utility Protection Center in Georgia, and Digger for the Chicago Utility

Alert Network. There are 84 one-call centers in the U.S. covering almost all areas of the

 32 As defined by One-Call Systems International (OCSI), a subgroup of the American Public Works

Association (APWA).

33 Pre-marking is discussed later in this chapter.
Chapter 3 Damage Prevention Practices 19

country.34 Of these, 55 are members of One-Call Systems International (OSCI). OSCI

members recorded over 13 million excavation notifications in 1996.35

In 1996, a nationwide referral number, 1–888–258–0808, was established by the

APWA and administered by Sprint. In the fall of 1997, this number was automated by

the APWA and is handled through the Georgia One-Call Center. A placard containing

this number is placed on all newly manufactured construction equipment; placarding resulted from coordination with the Equipment Manufacturers Institute. Ideally, a call to

that nationwide referral number would result in an automatic transfer to the appropriate

one-call center. This automatic transfer exists on a small scale for the State of California,

which uses two one-call systems but uses only one statewide phone number. However,

because automated switching of calls to the referral number would result in substantial

expenses for long distance telephone charges and billing, the existing referral service informs the caller of the correct one-call number, based on the caller’s identification of the

geographic location of the excavation, and the caller must then place a second phone call

to that center.

The organizational structure of one-call centers varies: some are functioning units

of the local ULCC; others are joint efforts of a few facility owners. Statutory language in

some States stipulates the composition of the Board of Directors (for example, Minnesota, North Dakota, South Dakota, Nebraska, and Oregon),36 but government involvement varies by State and by one-call center. Many one-call centers have been organized

as not-for-profit corporations that operate with a limited degree of State oversight. Their

administrative framework, funding arrangements, and operating procedures also vary.

For example, California allows local government agencies to recover all costs of one-call

membership through the permit fees that it charges contractors. Several States make participation by municipalities free. According to the OCSI, its member organizations were

“developed to best suit the needs of the underground facility owners in that state” and

“state laws do not govern the operation of a one-call system. The laws generally set out

who is required to belong to a one-call system and who must call a one-call system as

well as enforcement provisions. No two State laws are alike.” 37

Methods of Operation.—The differences in State involvement translate into very

practical distinctions between one-call centers. An assortment of communication methods are used to receive excavators’ calls and to issue notification tickets to the centers’

participants; centers may use telephone staff operators, voice recorded messages, e-mail,

 34 “Nationwide One-Call Directory.” Pipeline & Utilities Construction. April 1996.

35 Don Evans of USA South cited 13,362,684 in the “Options in Load Management” session at the 22d

annual One Call Systems and Damage Prevention Symposium, April 20–23, 1997, New York City.

36 Kelly, Walter. 1996. Making One-Call Work for You. Constructor, November 1996: 19.

37 Correspondence dated February 10, 1997, from L.D. Shamp, representing the OCSI, to the Association of Oil Pipe Lines. The letter offered comments and suggestions regarding the provisions of the proposed one-call legislation.
20 Chapter 3 Damage Prevention Practices

fax machines, Internet bulletin boards, or a combination of methods. Service hours may

be seasonally limited to a few hours a day or extend to 24 hours a day. Some locations

operate only seasonally because of construction demand; most operate year-round. Most

centers have statewide coverage but may not strictly follow State boundaries. A center

may cover portions of several States (Miss Utility in Virginia, Maryland, and the District

of Columbia) or there may be several centers within a State (Idaho has six different onecall systems; Washington and Wyoming each have nine). Centers may provide training

to the construction community, conduct publicity campaigns to educate the public to excavation notification requirements, and work with facility operators to protect their

underground facilities. Other centers do little work in these areas.

Some centers use positive response procedures—members who do not mark

facilities in the construction area confirm that they have no facilities in the area rather

than just not mark a location; other centers do not have this requirement. A part of the

Miss Utility program in the Richmond, Virginia, area uses positive response procedures

to notify the excavator when the marking is complete. Facility owners directly inform a

voice messaging system of the status of a notification ticket. (Notification tickets are

identified and discussed in the following section.) As a time-saving alternative, the

contractor can call the information system anytime to receive an up-to-date status of their

marking request. Information indicating that marking has been completed, or that no

facilities are located in the area of excavation, allows construction work to proceed as

soon as marking is completed rather than waiting the full time period for which marking

activity is allowed.

The important elements of an effective one-call notification center have been generally identified by industry organizations. For example, the position of the Associated

General Contractors of America on one-call systems38 is summarized in six elements:

mandatory participation; statewide coverage; 48-hour marking response; standard marking requirements; continuing education; and a fair system of liability. Participants at the

Safety Board’s 1994 workshop, on the other hand, developed detailed lists of elements

they believed are essential for an effective one-call notification center, other elements a

center should have, and elements it could have (appendix D). All agreed, however, that

first and foremost was the need for mandatory participation and use of notification centers

by all parties. The Safety Board concludes that many essential elements and activities of

a one-call notification center have been identified but have not been uniformly implemented.

Excavation Notification Tickets.—A record of a locate request is generally

called an excavation notification ticket, but there is no standard format for one-call excavation notification tickets. One-call centers track excavation activity based on the number of notification tickets they handle for their members, but they do not necessarily track

 38 Transportation Research Board, National Research Council. 1988. Pipelines and Public Safety.

Special Report 219 (p. 133). Washington, DC.
Chapter 3 Damage Prevention Practices 21

how many of those digging activities result in excavation hits. For the centers that do

maintain a record of hits, one-call members must report their hits to the center; the center

then compiles the information.

The OCSI Committee on Communication Standards is developing a universal

ticket format to address the problem of underground facility owners who work in different States and who receive tickets from more than one notification center.39 For large

companies working in different one-call areas, information that is organized into different

formats can be confusing and can lead to unsafe activities at the excavation site. According to discussions at the Safety Board’s 1994 workshop, the format needs to be consistent between centers, both in terms of ticket information and the work unit represented

by a ticket. For example, a ticket from one center might encompass work for all utilities

at a given two-block construction site, whereas another might separate tickets for each

utility, or by smaller geographic areas. Damage reports must also be consistent, and

OCSI is considering the feasibility of including damage information in the universal

ticket format. The committee expects to finalize a universal ticket format in January

1998. An example of a universal damage report form developed by Alberta One-Call is

included in appendix E. The Safety Board encourages the OCSI members and all other

notification centers to adopt a universal ticket format and to maintain ticket data. Standard ticket information would be an essential first step in developing performance measures for damage prevention programs. (Performance measures are discussed in more

detail in chapter 5.)

Effective Sanctions

Penalties for failure to act in accordance with State damage prevention programs

vary depending on location; provisions for oversight and timely enforcement can be quite

different from State to State. Administrative enforcement of State excavation damage

prevention laws does not require State court actions and has been shown to be effective in

several States. For example, in Pennsylvania’s new legislation (Act 187 enacted in

1996), the process of enforcement includes $100 and $200 citations for minor infractions

to the State’s excavation damage prevention law and $2,500 and $25,000 civil penalties

for more serious infractions. The Department of Labor and Industry is responsible for

administrative enforcement; the State’s Attorney General handles civil penalties.

The use of administrative enforcement is a characteristic of several State programs

for excavation damage prevention. The following examples from Massachusetts, Minnesota, and Connecticut illustrate three programs that operate differently but use administrative enforcement to effect safer excavation practices. The structure and cost of

 39 Underspace Bulletin 2(11): 2. August 1996. Spooner, WI: Center for Subsurface Strategic Action

(CSSA).
22 Chapter 3 Damage Prevention Practices

penalties for non-participation in the excavation damage prevention programs varies, but

the States’ common goal is to foster safe practices.

Massachusetts originally passed damage prevention legislation in 1959; it required

all excavators to notify utilities before they began to dig. Legislation in 1980 empowered

the Department of Public Utilities (DPU) with enforcement authority under the State’s

Administrative Procedures Act. Beginning in 1986, the Dig Safe Law enforcement was

delegated to the chief engineer in the pipeline engineering and safety division of the DPU.

A staff of one person handles the administrative enforcement of damage prevention for

the State of Massachusetts. That person has authority to issue notices of probable violation with fines that range from $200 to $1,000. In administering the program, the DPU

keeps fines at a reasonable level compared to many other States. Since 1986, the State

has issued over 3,000 notices; third-party damages dropped from 1,138 in 1986 to 412 in

1993. The Department requires utility companies to report any third party damages

within 30 days, and excavators are encouraged to send the Department violation notices

for State adjudication if they find fault with the utility companies. State utility owners

and excavators are provided books of violation tickets to document infractions of damage

prevention rules to the DPU. Using this mechanism, involved parties can notify the State

of problems, such as when facilities are mismarked or not marked within the required

time, when excavators do not use the notification system, or when line hits are not reported. The State has found that its readiness to dispense small penalties has resulted in

awareness of damage prevention throughout the industry. The State’s administrative enforcement process does not rely on the Attorney General’s office for execution; thus it

keeps State pipeline safety actions from being in direct competition with all other State

actions.

Other States have also found benefits from administrative rather than court enforcement of their regulations. Minnesota’s Department of Public Safety, Office of Pipeline Safety, takes complaints, investigates, and issues penalties of up to $500. The State

Office of Pipeline Safety, MnOPS, is the enforcement entity. Minnesota focuses strongly

on education as a key to the success of damage prevention. Violators of the regulation

often are allowed to institute training actions instead of paying fines.

Connecticut also uses an administrative process to enforce its damage prevention

program. Its Call-Before-You-Dig law, first passed in 1978, had only one penalty provision: if an excavator failed to call before digging and subsequently damaged facilities, the

excavator could be fined up to $10,000. A representative from Connecticut Call Before

You Dig has stated, however, because of the severity, the penalty was not used.40 An accident on December 6, 1985, in Derby, Connecticut, occurred when an excavator struck a

gas line; the excavator had used the notification system.41 Natural gas from the broken

 40 National Transportation Safety Board. 1995. Proceedings of the Excavation Damage Prevention

Workshop; September 8–9, 1994. Report of Proceedings NTSB/RP-95/01 (p. 16). Washington, DC.

41 National Transportation Safety Board Accident Brief DCA86FP004.
Chapter 3 Damage Prevention Practices 23

main migrated into the basement of a restaurant, exploded, and killed seven people. The

severity of this accident focused attention on the shortcomings of the existing law and

resulted in a change in the penalties, fines, and overall structure for enforcement. Connecticut created a position of compliance supervisor, an employee of the one-call center,

who serves as a field investigator and expert witness at that State’s DPU hearings. The

compliance supervisor receives incident reports and maintains case files on noncompliance. Connecticut law allows for fines on the first or second offense if the severity

of the offense, injuries, or past performance warrants. Otherwise, the compliance supervisor sends a letter to the party explaining the damage prevention program and stating

what compliance actions are needed. The DPU may send letters of inquiry or interrogatories, proceed with a docket for penalties, or schedule a “show cause” hearing. Offending

parties have 30 days to appeal by requesting a hearing. In 1994, excavation damage to

underground lines in Connecticut declined 28.5 percent compared to earlier years before

administrative enforcement. Of the 436 incidents of damage in that year, 223 were gas

lines, 91 were water lines, 78 were electric lines, 40 were communication lines, and 4

were sewer lines.42

Other States have implemented stringent programs for excavation damage prevention, with severe penalties for noncompliance. Because of its small area and concentrated population, New Jersey has a dense network of pipelines: 30,000 miles (48 270

kilometers) of intrastate lines and 1,000 miles (1609 kilometers) of interstate lines.43 As

a result of the 1994 accident in Edison, New Jersey, the State implemented heavy fines

and strong enforcement, effective in 1995. Digging near a gas line without calling for the

facility owner to mark the location can result in a $25,000 fine, and the company involved

in underground facility damage is required to provide a written plan for remediation and

training. The number of one-call notifications has increased 30 percent between 1995

and 1996. The New Jersey Board of Public Utilities recorded 2.2 million notifications for

1996. Even though there were 17 percent fewer hits in 1996, they still totaled 3,961. As

previously mentioned, however, the New Jersey State Department of Transportation is

exempt from participating in the one-call notification process.

Participants at the Safety Board’s 1994 workshop generally agreed that penalties

need to be enforced in order to recover the costs of the damage prevention programs;

however, the participants also believed that self-policing partnerships between operators

and excavators were essential and that the administration of the program should be as

simple and streamlined as possible with a minimum of government oversight. The participants believed that by doing so, costs to stakeholders would be minimized and there

would be a greater potential for success. The participants also indicated that State programs should have enough flexibility to be able to implement alternative procedures that

still meet the intent of the program.

 42 “Connecticut Data Reveals Damage Causes.” Underground Focus 10(5): 17. July/August 1996.

43 “New Jersey Takes a Hard Line on Underground Damage Prevention.” Underground Focus 11(3):

26–27. April 1997.
24 Chapter 3 Damage Prevention Practices

The administrative approach to enforcement of damage prevention programs is

designed to promote compliance rather than punishment, and to create awareness of good

damage prevention practices rather than to collect fines or to put small companies out of

business. Administrative enforcement has been accomplished without creating an additional bureaucracy, and the cost of the enforcement program has been covered even with

the small fines and penalties that are imposed. The Safety Board concludes that administrative enforcement has proven effective in some State excavation damage prevention

programs.

Excavation Marking

Excavation occurs frequently. The excavation notification system in Illinois recorded over 100,000 calls during the month of April 1997.44 In New Jersey, its one-call

system records 2.2 million excavation markings per year, an average of more than 6,000

per day.45 With this rate of occurrence, the frequency of hits would be dramatically

higher if some information about line locations were not available.

An entire industry of underground utility locating businesses have developed in

the last two decades. Primarily, these businesses serve utility companies by performing

the marking services associated with one-call notification. Referred to as locators, these

technicians visit construction sites and mark the location of underground facilities using

both mapping technology and electronic tools. Practices for marking the underground

facilities can have an impact on the risk of excavation damage. Good practices include

pre-marking the intended excavation site by the excavator to clearly identify to the facility

locator the area of digging; positive response by the utility owner to confirm that underground facilities have been marked or to verify that no marking was necessary; the use of

industry-accepted marking standards to unambiguously communicate the type of facility

and its location; marking facility locations within the specified notification time; and responding to requests for emergency markings, when necessary.

The timeframe for excavation marking is usually specified by State damage prevention laws. Twenty States require underground facility marking to be accomplished

within 48 hours of excavation notification. Construction work planning is not evenly

distributed throughout the week; consequently, one-call centers may schedule three or

four times the number of locates for some days compared to other days. This, in turn,

creates variable workloads for utility locators.

 44 “News Briefs.” Underground Focus 11(5): 14. July/August 1997.

45 “New Jersey Takes a Hard Line on Underground Damage Prevention.” Underground Focus 11(3):

26–27. April 1997.
Chapter 3 Damage Prevention Practices 25

Pre-Marking.—Participants at the 1994 workshop agreed that pre-marking the

proposed excavation area has been demonstrated to enhance the safety of excavation activities. Pre-marking allows the excavators to specifically tell facility owners where they

intend to dig. Some States require the use of white marking to indicate the boundaries of

planned excavations. Maine was one of the first States to have mandatory pre-marking

for non-emergency excavations. Connecticut has also adopted a pre-marking requirement; the law provides for face-to-face meetings between operators and excavators for

projects that are too large for or not conducive to pre-marking.

According to workshop participants, pre-marking an excavation site helps to ensure that owners of underground facilities are aware of the specific area that is to be excavated. Facility owners avoid unnecessary work locating underground facilities that are

not associated with the planned excavation. Excavators can be certain that underground

facilities within their intended area of excavation are well marked.

Because pre-marking defines the physical boundary of the excavation site, it removes ambiguity about what underground facilities need to be located. Marking the intended excavation area creates a greater likelihood that affected underground facilities

will be identified to the excavator. The Safety Board concludes that pre-marking an intended excavation site to specifically indicate the area where underground facilities need

to be identified is a practice that helps prevent excavation damage.

Marking Standards.—Most State laws on damage prevention call for facility

owners to follow the standards for temporary marking developed by the ULCC. Figure

3–1 identifies the color codes. Local one-call centers often distribute pocket-size flash

cards with these color codes to excavators. The use of standard marking colors informs

the excavator about the type of underground facility whose location has been marked.

Markings of the appropriate color for each facility are placed directly over the

centerline of the pipe, conduit, cable, or other feature. There are procedures for offset

markings when direct marking cannot be accomplished. For most surfaces, including

paved surfaces, spray paint is used for markings; however, stakes or flags may be used if

necessary. In addition to uniform color codes used to transmit standard information about

the type of facility marked, the National Utility Locating Contractors Association

(NULCA) has developed a proposal for standard marking symbols. The proposal is currently available only for internal use but is being designed for distribution to members in

the future. NULCA’s proposed standard addresses conventions for marking the width of

the facility, change of direction, termination points, and multiple lines within the same

trench. The standard symbology indicates how to mark construction sites to ensure that

excavators know important facts about the underground facilities; for example, hand-dig

areas, multiple lines in the same trench, and line termination points. The Safety Board

recognizes the benefit of industry efforts to standardize marking practices. Such conventions help to avoid misinterpretation between locators who designate the position of underground facilities and excavators who work around those facilities. Participants at the

workshop recommended that uniform marking include the facility owners’ identification.
26 Chapter 3 Damage Prevention Practices

NULCA’s work to define standard marking symbols incorporates the use of facility

owner’s identification marks along with conventions for identifying underground system

configurations.

Color Feature identified

red electric power lines, cables, conduit and

lighting cables

yellow gas, oil, steam, petroleum, gaseous materials

orange communications, alarm or signal lines, cable or

conduit

blue water, irrigation, and slurry lines

green sewers, drain lines

pink temporary survey markings

purple cable television

white proposed excavation

Figure 3–1. Uniform color code of the American Public

Works Association, Utility Location and Coordinating

Council.

Employee Qualifications and Training

Training to prevent excavation damage to the underground infrastructure is not

limited to the pipeline industry and operating personnel: locators need training in locating

techniques, equipment technology, and marking procedures; excavators need training to

fully participate in the notification process and to understand locator marking symbols;

one-call operators need training to efficiently and effectively transmit information between excavators and underground system operators; and the general public needs to be

aware of the one-call notification process when they dig for private projects. In addition,

anyone working to operate underground systems or whose work requires underground

digging needs to be trained in emergency response procedures. This diversity of training

needs presents a challenge to both system regulators and the industry.

Training and Educating Excavation Personnel.—Excavators need to be

trained and educated about safe work conditions, good excavation practices, relevant

State laws, and one-call procedures. In this context, the excavator is not only the backhoe

operator at the construction site, but also the project manager, the scheduler, company
Chapter 3 Damage Prevention Practices 27

officials—anyone connected to excavation work. In an effort to ensure that excavators

are aware of their responsibilities to protect underground facilities, some States have

licensing requirements that assess professional knowledge. For example, Florida law (in

Section 556.104 of the Florida Statutes) requires contractors who work near buried facilities to be licensed, a process that involves passing a written examination. Excavators

should fully understand the one-call notification process: the meaning of facility

markings, requirements for hand digging near underground facilities, notification

responsibilities when the scope of work changes, and emergency response procedures.

Many one-call centers offer outreach training programs designed for excavators. Some

one-call center personnel have met with local union organizations and industry

associations to explain the notification process and State damage prevention laws.

Because marking the position of an underground line is a safety-critical job,

training is necessary to ensure that locators are well prepared to perform this function.

NULCA has defined a set of minimum standards for its members to adopt as part of their

training programs.46 The program includes 118 hours of structured training in the topics

of system design, construction standards, equipment techniques, recognition of line type,

locating theory, and safety procedures. In addition to recommending the use of written

tests, the program recommends field training and annual re-testing.

The NULCA has also developed guidelines for excavation practices and

procedures for damage prevention. These guidelines, which were revised in September

1997, incorporate OSHA requirements and identify best practices applicable to

excavation work. Use of the guidelines is voluntary, but NULCA’s brochure explains

that legislation in most States requires contractors who plan to excavate to notify the

appropriate one-call center and non-member facility owners before the job begins.

Appendix F contains NULCA’s Excavation Practices and Procedures. The guidelines

address pre-planning and job site activities for both large and small projects. Instructions

for handling damage, along with a construction facility damage report form, are also

included. The Safety Board commends NULCA’s efforts in promulgating good practices

among its members and the excavation community.

Title 29 CFR 1926, Subpart P, contains several worker safety requirements on

excavation activities. In 1990, OSHA developed and issued a booklet, Excavation, to

assist excavation firms and contractors in protecting workers from excavation hazards.

The booklet is based on the requirements of Part 1926 and gives specific advice on

preventing cave-ins and providing protective support systems. OSHA employs several

methods of providing information to persons subject to its regulations; its latest

information system uses the Internet via the World Wide Web to provide assistance to

excavators and contractors on complying with OSHA requirements. Responses to

frequently asked questions, statistical data, news releases, OSHA pamphlets and

 46 National Utility Locating Contractors Association. 1996. Locator Training Standards & Practices.

Spooner, WI.
28 Chapter 3 Damage Prevention Practices

publications, and a listing of available training materials can be obtained via the

computer.

Federal training requirements for the transport of hazardous liquids are stated in

49 CFR 195.403. These are general requirements that do not specifically discuss excavation activities, and there are no comparable general training requirements for gas operator

employees. RSPA has a joint industry and government working group that periodically

meets to develop proposed requirements for employee qualification and training. That

committee, the Negotiated Rulemaking Advisory Committee on Pipeline Personnel

Qualifications, completed its fourth meeting in August 1997. It has prepared three drafts

of a proposed operator qualification regulation for committee consideration. The committee has not reached consensus and is still considering draft regulatory language.

Participants at the Safety Board’s workshop recommended that excavator associations work in conjunction with operators of buried facilities and one-call notification

centers to provide buried-facility damage-prevention training as part of their safety training programs. The participants acknowledged that the Associated General Contractors of

America and many contractor organizations are very safety conscious and have produced

several videotapes about safety issues. Few of these education efforts, however, include

testing. The current negotiated regulation process at RSPA has addressed the issue of

training verification and testing, but the scope of that work is limited to only oil and gas

operators subject to Federal regulations.

The Safety Board has long been concerned that all personnel involved in excavation activity be properly trained and qualified and has issued several recommendations in

this area as a result of its accident investigations. Following the investigation of an accident in Derby, Connecticut, in December 1985, the Safety Board recommended that

Northeast Utility Service Company

Emphasize in its training of operating personnel the importance of

following the company procedures for patrolling and protecting its gas

mains in proximity to excavation projects. (P-86-19)47

The Safety Board’s investigation of an accident that occurred 3 months later in Chicago

Heights, Illinois, also generated a recommendation concerning training. The Board

recommended that Northern Illinois Gas Company

Emphasize in company training the importance of following company

procedures for making areas near gas pipeline leaks safe for the public by

evacuation or other means. (P-87-38)48

 47 National Transportation Safety Board. 1986. Northeast Utilities Service Co. Explosion and Fire;

Derby, Connecticut; December 6, 1995. Pipeline Accident Report NTSB/PAR-86/02. Washington, DC. As

a result of the Northeast Utility Service Company’s positive response to Safety Recommendation P-86-19,

the recommendation was classified “Closed—Acceptable Action” on May 14, 1987.
Chapter 3 Damage Prevention Practices 29

As a result of an explosion and gas-fueled fire that occurred on July 22, 1993, when a

backhoe of the city of St. Paul Department of Public Works hooked and pulled apart a

high-pressure gas service line, the Safety Board asked the American Public Works

Association to

Advise its members of the circumstances of the July 22, 1993, explosion

in St. Paul, Minnesota, and urge them to develop and implement written

procedures and training to prevent excavation-caused pipeline damages.

(P-95-24)49

In 1987, RSPA first issued a notice of proposed rulemaking (NPRM) to improve

the competency of operator personnel and to set minimum training and testing standards

for employees of pipeline operators. A notice issued in October 1991 stated that a second

proposal, based on comments received earlier, would be forthcoming. By 1993, RSPA

still had not acted to implement any employee qualification and testing standards, and the

Safety Board urged that this issue become a priority in the regulatory agenda. Ten years

after its original NPRM in 1987, RSPA has entered into negotiated rulemaking. Action

on this issue is long overdue. The Safety Board concludes that employee qualification

and training is an integral component of an effective excavation damage prevention program, and industry has recognized the need for employee training but has not implemented training uniformly. Inadequate employee training was highlighted in the Safety

Board’s report of the San Juan accident.50 In that report, the Board recommended (P-97-

7) that RSPA complete a final rule on operator employee qualification, training, and testing standards within 1 year. The Board further stated in that recommendation that the

final rule should require operators to test employees on the safety procedures they are expected to follow and to demonstrate that they can correctly perform the work.

Because RSPA’s rulemaking would cover only those employees of oil and gas

operators subject to Federal regulations, additional efforts are needed by industry to

provide training materials to those employees not covered by the regulations. The

OCSI’s Training Committee—which develops educational materials for use by notification center employees, facility owners, and excavators—would appear to be the

appropriate organization to accomplish this goal. Therefore, the Safety Board believes

that the APWA should review existing training programs and materials related to

 

48 National Transportation Safety Board. 1987. Chicago Heights, Illinois; March 13, 1986. Pipeline

Accident Summary Report NTSB/PAR-87/01-SUM. Washington, DC. Safety Recommendation P-87-38

was classified “Closed—Acceptable Action” on September 29, 1988.

49 NTSB accident DCA93FP004. Safety Recommendation P-95-24 is currently classified “Open—Acceptable Response” pending receipt of further information from the APWA.

50 National Transportation Safety Board. 1997. San Juan Gas Company, Inc./Enron Corp. Propane Gas

Explosion in San Juan, Puerto Rico, on November 21, 1996. Pipeline Accident Report NTSB/PAR-97/01.

Washington, DC.
30 Chapter 3 Damage Prevention Practices

excavation damage prevention and develop guidelines and materials for distribution to

one-call notification centers.

Emergency Response Planning.—Pipeline operators are required by law to establish written emergency procedures for classifying events that require immediate response, communicating with emergency response officials, and responding to each type

of emergency.51 Although the extent of emergency response planning may vary depending on the type of excavation activity, emergency response planning should involve a

definition of responsibilities, a flow chart of actions, execution criteria, systems inventory

and resource information, coordination procedures (internal and external), and simulation

exercises of response actions.

Federal regulations require no emergency response plan for excavators; however,

these are the very people that often have responsibility for first response at an excavation

disaster. The Safety Board has addressed the need for emergency response plans and procedures in many of its reports of accidents involving excavation damage. One such accident was an explosion in Cliffwood Beach, New Jersey, on June 9, 1993, that occurred as

a result of a utility contractor’s trenching operation. The Safety Board’s investigation

determined that a failure in training was causal to the accident.52 The utility operator did

not brief or determine whether the contractor knew what procedures to follow should the

crew damage a main or service line. In addition, the Safety Board found no record or

evidence of the contractor being properly trained in emergency procedures, and the facility operator’s procedures did not include emergency response training for contractors. As

a result of its investigation, the Safety Board recommended that the gas company take the

following actions:

Train all gas operations construction contractors for emergencies involving

struck pipelines; training should stress immediately reporting natural gas

pipeline strikes to New Jersey Natural Gas’s emergency phone number.

(P-94-01)53

As a result of the previously mentioned accident in St. Paul, Minnesota, on July 22, 1993,

the Safety Board recommended that the American Public Works Association

Urge your members to call 911 immediately, in addition to calling the gas

company, if a natural gas line has been severed. (P-95-25)54

 51 49 CFR Part 192.615, “Emergency plans” [for gas pipelines]; and Part 195.402, “Procedural manual

for operations, maintenance, and emergencies” [for hazardous liquids].

52 NTSB accident DCA93FP008.

53 On August 1, 1995, the Safety Board classified this recommendation “Closed—Acceptable Action.”

54 This recommendation is currently in an “Open—Acceptable Response” status pending further action

by the APWA.
Chapter 3 Damage Prevention Practices 31

The Safety Board concludes that, at a minimum, excavators should formulate an

emergency response plan appropriate for the specific construction site and ensure that

employees working at that site know the correct action to take if a buried facility is damaged. The local one-call center can also play an important role in planning with local officials to define the best emergency response appropriate for its communities. The local

one-call centers also are in a good position to disseminate this information on a regular

basis. Therefore, the Safety Board believes that the APWA should 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.

Discussion

The Safety Board acknowledges that considerable progress has been made by

RSPA and the industry in the area of improving excavation damage prevention programs

since the Board’s 1994 workshop and most likely because of it. The workshop provided

a valuable forum to discuss how government and industry can work together to improve

excavation damage prevention programs. The Safety Board believes that by continuing to

focus attention on this important safety issue, the number of excavation-caused accidents

to the Nation’s underground facilities will ultimately decrease. Therefore, the Safety

Board believes that RSPA should 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.

Specific progress has been made to standardize marking symbols, to develop a

uniform notification ticket, to develop guidelines for excavation practices and procedures,

and to develop minimum standards for training programs. The importance of mandatory

participation has been advocated by industry as well as government, yet many entities are

granted exemptions to participation in State excavation damage prevention programs.

Although many elements of an effective State excavation damage prevention program

have been identified, the Safety Board is concerned that these elements have not been

uniformly implemented. Some States have realized the benefit of swift, effective sanctions through the administrative process, yet many States are lacking effective enforcement programs. The practices and activities of one-call notification centers have also

been identified, but these practices have not been uniformly implemented. The Safety

Board concludes that although considerable progress has been made to improve State excavation damage prevention programs, additional efforts are needed to uniformly develop

and implement programs that are most effective.

In 1996, RSPA established a joint government/industry Damage Prevention Quality Action Team. Participants include the American Petroleum Institute (API), the

American Gas Association (AGA), the American Public Gas Association (APGA), the
32 Chapter 3 Damage Prevention Practices

 Interstate Natural Gas Association of America (INGAA), One-Call Systems International

(OCSI) of the APWA, the National Telecommunications Damage Prevention Council, the

National Association of Regulatory Utility Commissioners (NARUC), the Associated

Electrical and Gas Insurance Services, the National Association of Pipeline Safety Representatives, and industry participants. As stated in its charter, “the purpose of that team is

to assess the status of current excavation damage prevention efforts and their effectiveness, and to identify additional efforts that would lead to reduction of excavation damage.” However, rather than assessing the status of damage prevention efforts, the group

set as its goal to “conduct a national pipeline awareness campaign.” As of June 1997, the

team had developed and distributed surveys to assess the awareness of one-call systems.

Because the critical elements of an effective excavation damage prevention program have

not been uniformly implemented at the State level, the Safety Board believes there is a

need to review and evaluate existing damage prevention programs and to highlight deficiencies in existing programs so that corrective action can be taken. The Safety Board

supports current legislative interest in provisions for a review of existing excavation damage prevention programs but does not believe there is a need to await Congressional action before such an evaluation is undertaken. The Damage Prevention Quality Team

appears to be an appropriate mechanism for accomplishing a detailed evaluation of existing programs. Therefore, the Safety Board believes that RSPA, in conjunction with the

APWA, should initiate and periodically conduct 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.
Chapter 4 Accuracy of Facility Information 33

Chapter 4

Accuracy of Information

Regarding Buried Facilities

Underground Detection Technologies

Both facility owners and excavators have genuine interest in identifying the location of underground facilities. But with current locating equipment technologies and

mapping records, there remains a variety of errors that can potentially affect the ability to

positively identify the position of underground facilities. There is no one procedure or

tool that can provide accurate location information for all types of facilities in all types of

situations. Location work is a combination of operator experience and the correct use of

technology.

A variety of remote sensing technologies can be used for detecting underground

facilities. Different types of locating equipment and techniques are needed depending on

structural composition of the buried materials, soil composition, and surface access.55 A

brief description of the types and attributes of locator tools is shown in table 4–1.

In addition to equipment choice, there are situational variables that affect detection

accuracy. The more conductive the soil, the more shallow the conductor will appear.

Sandy, loose soil with a high mineral content will give sensitive readings; pipe locations

under these conditions may be deeper than the locator equipment readings indicate.

Moisture content or water table levels can also affect depth readings.

For equipment types that determine location by sensing an electronic signal that

has been introduced into the underground system, strength of the locating signal depends

on where the signal was introduced into the system, the proximity of structural uprights

connected to the underground system, and nearby surface obstructions that dissipate the

signal. Selection of radio signal frequency can also affect signal clarity. Equipment

readings cannot be taken as absolute values; they depend on situational effects associated

with locator equipment calibration, field conditions, and the operators familiarity with the

particular operating characteristics.

 55 Anspach, J.H. 1994. Locating and Evaluating the Conditions of Underground Utilities. In:

RETROFIT ’94. Washington, DC: National Science Foundation. Sponsored by: Stanford University and the

National Science Foundation.
34 Chapter 4 Accuracy of Facility Information

Table 4–1. Types of locator equipment.

Equipment type Functional description Attributes

Radio frequency (RF)

detection techniques

Conventional underground line detection

method. Requires a transmitter and a

receiver. Conductive tracing attaches the

transmitter directly to the line or tracer wire.

Inductive tracing does not require direct line

connection.

Oldest, most widely used

technology. Inductive signal

detection is quicker, but

conductive signal reading is

more accurate.

Electromagnetic

techniques

Records signal differentials of magnetic

fields. Similar to radio frequency

technology.

Useful for detecting metal

objects or structures that

exhibit strong magnetic fields at

the ground surface. This type

of detector is affected by

obstructions between the

transmit signal and the locating

equipment.

Magnetic methods Useful for detecting iron and steel facilities. Magnetic flux methods are

easy to use and inexpensive,

but they are subject to

interference from metal surface

structures.

Vacuum extraction Small test holes are dug from the surface

by vacuuming out the soil. The activity,

usually referred to as “potholing,” follows

more preliminary locating work to identify

the general facility location. The pothole

then confirms the location and verifies a

depth for that specific site.

Requires preliminary records

search to approximate location

for potholing and special

vacuum equipment. Process

can be expensive and labor

intensive.

Ground penetrating

radar

Radar wave reflections from underground

surfaces of different dielectric constants are

used to identify subsurface structures.

This method is relatively

expensive compared to other

locator methods and does not

work well in clay or saltwater.

Terrain conductivity Detects current measures that differ from

average ground surface conductivity.

This method can be useful in

areas of high conductivity, such

as marine clay soils,

particularly for locating

underground storage tanks.

Global positioning

system (GPS)

Uses triangulated satellite telemetry to

identify latitude/longitude location of ground

unit.

While not a detection

technology, GPS coordinates

are frequently used to define

geographic location.

Adapted from: Anspach, J.H. 1994. Locating and Evaluating the Conditions of Underground Utilities. In: RETROFIT

’94. Washington, DC: National Science Foundation. Sponsored by: Stanford University and the National Science

Foundation.
Chapter 4 Accuracy of Facility Information 35

Many water and sewer lines are made of plastic or concrete pipe, gas systems

commonly use plastic pipe, and fiber optic cable is often used in telecommunication lines.

These systems are difficult to detect with common locator tools because they do not contain metal. A metal tracer wire can be buried with the pipe to facilitate future locating

work. Typically, pipe is laid in the trench and covered by a shallow layer of fill dirt. The

tracer wire is then placed over the pipe and trench filling is completed. Detectable warning tape—aluminum foil covered with color-coded polyester—can be buried with nonmetallic underground facilities to permanently mark the lines. Varieties of tracer wire and

detectable warning tape are designed to be sturdy enough to be plowed into the trench

during backfill operations.

The Safety Board recognizes industry efforts to inform locators about issues

relevant to locator technology. Underground Focus magazine sponsors an annual utility

locating technology seminar. This training event, currently in its 6th year, provides

information on utility locating techniques, equipment, and new technology. Participants

include locators, equipment manufacturers, engineers, trade association representatives,

and academic interests. Topics related to locator equipment are also regularly addressed at

conferences such as the annual OCSI symposium and the Underground Safety Association

forum.56

Vertical/Depth Location

The only certain method of determining facility depth is to expose the pipe, conduit, or cable through hand digging or through vacuum excavation. Southwestern Bell’s

use of vacuum excavation to expose and document exact facility locations is credited with

decreasing cable damages by 50 percent in Texas during 1996.57 This method positively

identifies both the horizontal and vertical location of the pipe at a specific site. But certainty about the line’s position is inversely related to its distance from the test hole. Depth

depends on how the line was installed and on the changes in surface grade caused by erosion or construction since installation.

For selected models of locating equipment, manufacturers claim that the units can

accurately determine depth.58 Accurate depth measurements are a highly desirable attribute of locating equipment. Based on equipment manufacturers’ claims, States have begun

 56 OCSI will hold its 23d

 annual symposium in March 1998, and the Underground Safety Association

will hold its forum in February 1998.

57 Underspace Bulletin 3(7): 2. April 1997. Spooner, WI: Center for Subsurface Strategic Action

(CSSA).

58 According to advertisements for the Sure-Lock locator by Heath Consultants, that equipment provides

a continuous depth reading. Other equipment manufacturers, Fisher TW-770 and Metrotech 9800, advertise

a pushbutton feature for digital display of depth.
36 Chapter 4 Accuracy of Facility Information

to consider adding requirements for depth location information to their damage prevention

legislation. Wyoming’s Underground Facilities Notification Act of 1996 requires construction project owners to furnish information on the nature, location, and elevation of

underground facilities.59 Minnesota is considering a similar requirement.

Remote locating devices that measure depth are susceptible to calibration

problems, antenna misalignment, and electronic fields that are combined from more than

one surface conductor.60 The capability for accurate depth measurement may exist under

ideal situations, but given field conditions, depth measures may lack a high rate of

reliability. Participants in the 1994 damage prevention workshop concluded that remote

sensing methods should not be used for determining facility depth location. More recently, at the 1997 One-Call Systems and damage prevention symposium, a session on

depth perception concluded that remote locator equipment was available that could provide elevation readings but not with a degree of accuracy that warrants placing the liability

with the locating service.61

The capability of locator equipment needs to be incorporated into damage prevention practices. The Safety Board concludes that more research and testing is needed to

determine the accuracy of depth detection by remote locating equipment. Therefore, the

Safety Board believes that RSPA should sponsor independent testing of locator equipment

performance under a variety of field conditions. Further, the Board believes that as a result of the testing, RSPA should develop uniform certification criteria of locator equipment. Finally, once locator equipment performance has been evaluated and defined by

certification criteria, RSPA should review State requirements for location accuracy and

hand-dig tolerance zones to determine that they can be accomplished with commercially

available technology.

Directional Boring/Trenchless Technology

Excavation work is frequently for the purpose of installing additional facilities.

General practices require digging an open trench from the surface down to the installation

depth. However, trenchless technology offers a different method for installing underground facilities. Directional boring “snakes” a new line that follows a drill bit horizontally through the subsurface. This method is particularly advantageous for traversing

 59 “Wyoming’s Unique One-Call Legislation.” Constructor, November 1996:17.

60 Anspach, J.H. 1994. Locating and Evaluating the Conditions of Underground Utilities. In:

RETROFIT ’94. Washington, DC: National Science Foundation. Sponsored by: Stanford University and the

National Science Foundation.

61 “Depth Perception” session at the 22d

 annual One-Call Systems and damage prevention symposium,

April 20-23, 1997, New York City. Panel participants at the moderated session represented equipment

manufacturers and underground locator services.
Chapter 4 Accuracy of Facility Information 37

below waterways, ecologically sensitive wet lands, or major traffic arteries. But there are

practical limits to the depth that lines are installed. Eventually, additional depth becomes

infeasible because of the cost of the extended line runs, geologic changes at lower stratum,

or practical concerns for future maintenance. New lines must then go through the areas

that have had line laid by directional boring.

Differences in soil density, rock formations, and variable torque on the drilling

head often result in a directional line that does not run along a straight route. Drilling

heads can be deflected by hard rock or unknown underground objects. The operational

accuracy of directional boring depends on the accuracy of sensors located on the drill bit

and the drilling unit’s resolution and correlation to a common base map. Though they do

not involve sensors, similar problems can be found with the use of pneumatic drills and

mechanical augers.

Directional boring is not always sensitive to line hits; it is possible for a boring

equipment operator to hit a facility without being aware of the hit. The drill bits, designed

to go through rock, experience little change in resistance when going through plastic pipe

or cable. This sets up a situation for hitting a gas line without knowing it; migrating gas

can then collect, creating conditions for an explosion. The Safety Board recently investigated an accident involving directional boring in Indianapolis, Indiana.62 The explosion

resulted in one fatality, one injury, and extensive damage to a residential subdivision.

Over the past year, the trade literature has documented several accidents, not

investigated by the Safety Board, that resulted from horizontal directional boring. For

example:

• In Seattle, directional boring caused a gas explosion that destroyed a home;

• A major traffic artery in northern New York State was closed for several days

to determine if a water main break resulting from directional boring had

seriously weakened the roadbed; and

• Two people were hospitalized in Overland Park, Kansas, when a gas

explosion, caused by directional boring, destroyed four homes.63

Equipment manufacturers have tried to address the problem of recording the position of lines installed by directional boring. Sensors, generally magnetic guidance-type

sensors attached to the drill bit, record location information for mapping the line. The

relative position of the drill bit is plotted on a real-time display at the drilling operator’s

control position.64 Stored as an electronic data file, this information can be archived in

 62 NTSB accident DCA97FP005; the accident occurred on July 21, 1997.

63 (a) Underground Focus 10(6): 16–19; 22–23. September/October 1996. (b) Underground Focus

10(7): 18–19. November/December 1996.

64 Configuration of the Mole Map System developed by McLaughlin Boring Systems.
38 Chapter 4 Accuracy of Facility Information

facility data records. Conceptually, this accounts for “recording the course of a new line.”

Associated issues, however, can affect the accuracy of information gathered in this manner. First, accuracy depends on sensor calibration. Operators must know how to check for

and correct calibration error. Second, the drill’s sensor may know where it is in relation to

some global positioning system (GPS) coordinates, but it may not know its location in relation to ground surface. Depth of line, an important fact, is dependent on accurately orienting the drilling activity on a topographic survey map. The accuracy of the topographic

map is, in turn, affected by erosion and grade changes over time.

The Safety Board concludes that facility maps should have a standard depiction for

underground facilities that were installed using directional boring techniques. The Safety

Board believes that the APWA should work in conjunction with the American Society of

Civil Engineers (ASCE) to develop standards for map depiction of underground facilities

that were installed using directional boring techniques.

Mapping

Maps are important to many aspects of excavation damage prevention. Rather

than using a standard, common mapping system, current damage prevention programs use

many different maps. An excavator usually uses a city road map to identify to the one-call

center the intended area of construction activity. The one-call center refers to its coverage

map (grid system coded with database information) to identify which facility owners

should be notified to mark their underground facilities. Locators use a combination of

utility maps to direct their field work.

Engineers and project designers are forced to use a variety of data sources from

both public and private organizations to determine the structure and location of the underground facility network. Land use and zoning maps, tax assessor maps, easement descriptions, highway and transportation network maps, quadrangle and topographic maps of the

U.S. Geologic Survey, construction permit drawings, construction plans, and aerial photographs are also used to help define the location. As the following example illustrates, map

quality can vary. Excavation to install telephone cable on the University of New Haven

campus in Connecticut in August 1996 hit a gas main, but the gas did not ignite. The gas

crew searched for 33 minutes to find the correct shutoff valve. The director of facilities

for the university said the gas line was not marked on maps of the campus.65

 65 Underground Focus 10(6): 17. September/October 1996.
Chapter 4 Accuracy of Facility Information 39

Facility records maintained by the utility owners or pipeline operators are the most

widely used sources of information about the underground infrastructure. As a result of

the Pipeline Safety Act of 1992, OPS requires operators to identify facilities in environmentally sensitive areas and in densely populated areas, but there is no requirement for

system operators to maintain a comprehensive system map of their underground facilities,

though most do maintain this information to facilitate their business operations. Different

utility services use different types of maps; they vary in scale, accuracy, resolution, standard notation, and data format. System records developed prior to the widespread use of

computer technology most likely exist as architectural and engineering diagrams. For

some systems, these diagrams have been electronically imaged so that they are easier to

reference, update, and store. Digitized versions of early maps do not always reflect the

uncertainty of information that may have been inherent on the hand-drafted version.

Structural references and landmarks that define the relative locations of underground facilities also change over time and may not be reflected on maps.

Many system maps lack documentation of abandoned facilities. Abandoned facilities result when the use of segments of the underground system are discontinued, or

when replaced lines run in new locations, or when entire systems are upgraded. Without

accurate records of abandoned facilities, excavators run the risk of mistaking the abandoned line for an active one, thereby increasing the likelihood of hitting the active line.

Several States have recognized the need to require facility operators to map abandoned

lines; for example, Arizona requires that any line abandoned after December 1988 be

mapped.

In addition to documenting the location of a facility, utility map records may also

contain information on the age of the facility, type and dimensions of the material, history

of leakage and maintenance, status of cathodic protection, soil content, and activity related

to pending construction. However, the quality of this information varies widely. Participants at the 1994 damage prevention workshop recommended that when excavation revealed errors in mapping, operators should be required to update system maps.

Recent utility records often exist as geographical information systems in a variety

of computerized software packages and electronic data storage formats. The Mapping Requirements and Standards task group of the AGA’s Distribution Engineering Committee

surveyed member companies in 1995 about mapping requirements and practices. Of the

27 companies that responded, 12 used computer-based mapping systems, 12 others were

planning to automate their mapping systems, and 3 reported that they had no plan to automate mapping records.66

Many automated mapping programs are not compatible, and it is difficult to merge

system records developed over the years by different departments and companies.

 66 Place, J.C. 1996. “Gas Utility Mapping: What’s Needed, What’s Used.” Gas Industries, January: 21–

22.
40 Chapter 4 Accuracy of Facility Information

Additionally, computerized diagrams may be associated with large databases that contain

entry errors that are difficult to identify. Inconsistencies between data dictionaries—similar information labeled differently in different databases—require considerable effort to

correct once identified. More importantly, these differences may lead to an unknown error

if they are not resolved. A good quality printed image of an electronic map can disguise

the poor level of information used to generate the image.

One-call systems are beginning to use GPS receivers and mapping programs.67

Arizona Blue Stake One-Call and Ohio Utility Protection Service are working to develop

positionally accurate, map-driven software to support their notification systems. California’s USA North One Call ticket locations can be displayed as GPS coordinates.68 Excavators, locators, and utility operators can use GPS information to identify field locations

(longitude and latitude coordinates), and they can use this information to navigate to the

sites. With the added capability of differential GPS, objects can be located to an accuracy

of better than 1 meter (1.1 yards). This degree of accuracy makes differential GPS appropriate for many aspects of mapping underground facilities. The Tennessee One-Call System is considering the feasibility of installing differential GPS antennas across the State to

provide location accuracy.

Most commercial maps are based on topographically integrated geographic encoding and referencing (TIGER) files from the U.S. Census Bureau. These files often

contain positional inaccuracies that can be problematic when integrated with GPS latitude

and longitude coordinates. For example, many, if not most, existing underground systems

are not documented by GPS coordinates. Consequently, a facility owner working on a line

may want to update the positional record of that line to include the coordinates. Using a

GPS receiver, the facility owner acquires the line’s position and then references a TIGERbased map for that area to verify aboveground landmarks. The map can indicate that those

coordinates are on the south side of the highway, yet the locator might actually be standing

above the underground facility on the north side of the highway.

In 1994, the Federal Geographic Data Committee recommended a plan for the Nation’s spatial data infrastructure, and Congress mandated governmental response to the

plan.69 The OPS subsequently formed a joint government/industry team to start a national

pipeline mapping system. The team’s 1996 report, “Strategies for Creating a National

Pipeline Mapping System,” made several recommendations: (1) develop, promote, and

aggressively communicate pipeline data standards that are consistent with the standards of

the Federal Geographic Data Committee; (2) formalize a partnership with industry, and

 67 Vista One Call Mapping Program by Kuhagen, Inc., is compatible with California’s USA North One

Call System and has been accepted for use by the State fire marshal as a method for digitizing pipeline mapping.

68 “One-Calls Eye New Mapping.” Underground Focus 10(2): 6. Symposium Edition 1996.

69 The Federal Office of Management and Budget (OMB), under the directive of OMB Circular A16,

created the Federal Geographic Data Committee, which is chaired by the Secretary of the Interior. The 1994

Plan for the National Spatial Data Infrastructure was issued in March 1994.
Chapter 4 Accuracy of Facility Information 41

Federal and State agencies; (3) develop a partnership with One-Call Systems International

to reach a better understanding of one-call system data needs and gather support for using

geographically referenced data; and (4) create a distributed mapping system with centralized quality control and decentralized access capabilities.

There are many different facility mapping systems in use by one-call systems and

facility owners. Those with GPS positional accuracy lack information on landmarks and

developed structures, and maps that accurately reflect current structural improvements often lack positional accuracy. The Safety Board concludes that underground facility mapping must consider the amount of detail and the accuracy of information necessary for

effective use. The Safety Board recognizes RSPA’s effort in creating strategies for a national pipeline mapping system and for its current Mapping Implementation Quality Action Team. The Board believes RSPA should develop mapping standards for a common

mapping system, with a goal to actively promote its widespread use.

Subsurface Utility Engineering

Subsurface utility engineering (SUE) is a process for identifying, verifying, and

documenting underground facilities. Depending on the information available and the

technologies employed to verify facility locations, a level of the quality of information can

be associated with underground facilities. These levels, shown in table 4–2, indicate the

degree of uncertainty associated with the information; level A is the most reliable and

level D the least reliable. This categorization is a direct result of the source of information

and the technologies used to verify the information.

A comprehensive map and automated computer diagram of a construction site is

developed as a SUE product; it depicts co-registered information for all utilities in that

area. The SUE process identifies all utilities during a single coordinated effort. In this

way, information known about one facility can beneficially affect the mapping of other

utilities, and unknown facilities are more likely to be documented. By signing the SUE

product, a professional engineer warrants the maps against errors and omissions and assumes liability for the accuracy of the information.

The Federal Highway Administration (FHWA) considers SUE an integral part of

preliminary engineering work on highway projects receiving Federal aid. It has the

potential to reduce facility conflicts, relocation costs, construction delays, and redesign

work. In 1984, the State of Virginia began a SUE program, called the Utility Designation

and Locating Program, and determined that there were substantial cost savings. A highway project in the city of Richmond used SUE work costing $93,553 to avoid an estimated

$731,425 worth of expenses to move utilities had the highway projects not been designed

to avoid conflict with underground facilities. Virginia’s estimate of cost savings, just in

terms of avoiding utility relocations, was $4 saved for each dollar spent.
42 Chapter 4 Accuracy of Facility Information

Table 4–2. Subsurface utility engineering (SUE) levels of information.

Quality level of

the information Description

Level D Information is collected from existing utility records without field activities to

verify the information. The accuracy or comprehensiveness of the information

cannot be guaranteed; consequently, this least certain set of data is the lowest

quality level.

Level C Adds aboveground survey data (such as manholes, valve boxes, posts, and

meters) to existing utility records. The Federal Highway Administration Office of

Engineering estimates that 15–30 percent of level C facility information pertinent to

highway construction is omitted or plotted with an error rate of more than 2 feet.(a)

Level B Confirmed existence and horizontal position of facilities are mapped using

surface geophysical techniques. The two-dimensional, plan-view map is useful in

the construction planning phase when slight changes to avoid conflicts can

produce substantial cost savings by eliminating the relocation of utilities.

Level A Vacuum excavation is used to positively verify both the horizontal and vertical

depth location of facilities.

(a) Scott, Paul. 1995. “Subsurface Utility Engineering: An Alternative to Excavation Damage.” In: Proceedings,

Excavation Damage Prevention Workshop; 1994 September 8-9; Washington, DC. Report of Proceedings NTSB/RP95/01. Washington, DC: National Transportation Safety Board: 186-189.

Source: Stutzman, H.G.; Anspach, J.H. 1993. “Site Investigation and Detection.” In: Research Needs in Automated

Excavation and Material Handling: Proceedings, National Science Foundation Symposium; 1993 April. Washington,

DC: National Science Foundation.

Additionally, Virginia credits the process with reducing design time by 20 percent.70 The

utility coordinator for Maryland’s State Highway Administration estimates a savings of

$18 for each dollar spent. Florida DOT found that it saved $3 in contract construction

delay claims for each dollar spent on SUE. Variations in these estimates reflect different

cost assumptions, geographic conditions, and system configurations. Twenty-six highway

agencies have used SUE at some level on some projects;71 FHWA estimates a nationwide

savings of $100 million a year as a result of SUE.72

Compiling comprehensive information on underground facilities can be expensive

and labor intensive. Small contractors generally do not have the resources or expertise

available to accomplish SUE on a regular basis; consequently, SUE is generally used on

large construction projects such as those typical of highway development.

 70 U.S. Department of Transportation, Federal Highway Administration. 1995. Subsurface Utility Engineering Handbook. FHWA-PD-96-004 (p. I–14). Washington, DC. November.

71 According to the FHWA, Maryland, Pennsylvania, Delaware, North Carolina, and Arizona use SUE

on an extensive basis.

72 U.S. Department of Transportation, Federal Highway Administration. 1995. Subsurface Utility Engineering Handbook. FHWA-PD-96-004 (p. I–29). Washington, DC. November.
Chapter 4 Accuracy of Facility Information 43

Architects, engineers, and contractors should have ready access to information on

the location of underground facilities to plan construction activities. The advantage of this

information was recognized at the 1994 damage prevention workshop. The Safety Board

concludes that providing construction planners with information on the location of underground facilities, referred to as “planning locates,” can reduce conflicts between construction activities and existing underground facilities. The Safety Board believes that the

APWA should encourage one-call notification centers to work with their members to provide facility location information for the purpose of construction planning.

The Standards Committee of the ASCE is developing standards for depicting underground facilities on construction drawings. The Board thus believes that the APWA

and the ASCE should address the accuracy of information that depicts subsurface facility

location on construction drawings. Further, the Safety Board believes that the Associated

General Contractors of America should promote the use of subsurface utility engineering

practices among its members to minimize conflicts between construction activities and

underground systems.

Chapter 5 System Performance Measures 45

Chapter 5

System Performance

Measures

Few performance-based measures are available and useful for assessing excavation damage prevention programs. Those measures that are maintained are specific to

selected States or are maintained by individual companies for a specific underground

system. Data concerning underground damage for all types of systems are needed: (1) to

determine if changes to State damage prevention programs are effective in decreasing underground facility damage; (2) to assess the benefit of different practices followed by onecall notification centers; (3) to identify the risks of different field practices used by facility operators, locators, and excavators; (4) to allow facility operators to evaluate their

company’s excavation damage prevention programs; (5) to assess the needs and benefits

of training; and (6) to perform risk assessment for the purposes of business, insurance,

and public policy decisions.

Risk Exposure

A critical component of excavation damage data is the total number of

excavations that present a chance for damage. These data, however, are not available.

The number of excavations presented in this report are industry estimates; they did not result from a national data collection system. To quantify the number of accidents in

relation to how many could have occurred, it is necessary to determine some frequency of

exposure. In the context of excavation damage, exposure can be measured by the number

of excavations. This measure can be approximated by the number of locate tickets issued

by one-call centers, although that number will capture only those excavations that were

reported to one-call centers.

One-call centers offer the best opportunity for the industry as a whole to determine the rate of excavation damage. The OCSI Delegate Committee is developing a process to standardize and collect one-call center information from its members. To be

useful, the information will need to be qualified by reporting criteria. Categories will

need to be clearly defined: what is an excavation activity, what constitutes a facility hit,

how is the level of damage categorized, what caused the damage?

Many facility operators, particularly companies that transport gas and hazardous

liquids, investigate and record “line hits” in terms of damages per thousand locate
46 Chapter 5 System Performance Measures

requests. But because of proprietary interests, these numbers are rarely compiled across

companies. The Gas Research Institute’s (GRI) 1995 study made an effort to determine

risk exposure for the gas industry.73 The study surveyed 65 local distribution companies

and 35 transmission companies regarding line hits. Less than half (41percent) of the

companies responded, and several major gas-producing States were poorly represented

(only one respondent from Texas and one from Oklahoma). The GRI estimate was determined by extrapolation and may be subject to a large degree of error because the data

sample was not representative. Based on survey responses, however, GRI calculated an

approximate magnitude of risk. For those companies that responded, a total of 25,123

hits to gas lines were recorded in 1993; from that, the GRI estimated total U.S. pipeline

hits in 1993 to be 104,128. For a rate of exposure, this number can be compared to pipeline miles: for 1993, Gas Facts reported 1,778,600 miles (2 861 767.4 kilometers) of gas

transmission, main, and service line, which calculates to a risk exposure rate of 58 hits

per 1,000 line miles (1609 kilometers).74

Because the risk of excavation damage is associated with digging activity rather

than system size, “hits per digs” is a useful measure of risk exposure. For the same year

that GRI conducted its survey, one-call systems collectively received more than an estimated 20 million calls from excavators. (These calls generated 300 million work-site

notifications for participating members to mark many different types of underground

systems.) Using GRI’s estimate of hits, the risk exposure rate for 1993 was 5 hits per

1,000 notifications to dig.75 A comprehensive measure of hits per digs tracked over time

can be a useful indicator of how well excavation damage prevention programs are performing. Because the measure is expressed as a rate rather than simply a number of hits,

it can be used to compare years in which there were different levels of construction activity. The measure can also be used to compare geographic locations or utility systems of

different size. Industry is beginning to use such measures of performance; for example,

measures of hits per locates have been incorporated into contractual agreements between

utilities and their locator services.76

 73 Doctor, R.H.; Dunker, N.A.; Santee, N.M. 1995. Third-Party Damage Prevention Systems. GRI95/0316. Final report, contract 5094–810–2870. Chicago, IL: Gas Research Institute. 67 p., plus

appendixes.

74 Calculated as total hits (104,128) ÷ miles of gas line (1,778,600) = 0.0585 hits per mile or 58.5 hits

per 1,000 miles. (104,128 hits ÷ 2 861 767.4 kilometers = 0.0364 hits per kilometer or 36.4 hits per 1000

kilometers.) Note: Different categories of gas lines were added together. Transmission lines have a substantially lower rate than other gas systems: survey respondents reported 201 hits per 36,042 line miles

(57 992 kilometers), for a rate of 5.5 hits per 1,000 miles (1609 kilometers). However, GRI survey numbers account for only 10 percent of the U.S. gas transmission system. If the number of transmission system

hits per 1,000 miles is separated from the U.S. total, the rate for local distribution companies increases to 71

hits per 1,000 miles.

75 Calculated as total hits (104,128) ÷ excavation notifications (20,000,000) = 0.0052 per notification

or 5.2 per 1,000 notifications.

76 Northern Illinois Gas incorporated a performance incentive based on hits per locates into its most recent locator service contract with Kelly Cable Corporation.
Chapter 5 System Performance Measures 47

The Safety Board is encouraged that attempts are being made to calculate risk exposure data. Without this information, evaluations on the effectiveness of State damage

prevention programs cannot be adequately performed. The Safety Board is concerned,

however, that these isolated attempts to calculate exposure data are neither standardized

nor centrally reported. A “utility” in one State may be defined differently for another

State, resulting in inconsistent measures of damage.

If all digging activity were recorded through one-call systems, notification ticket

volume would be a useful measure of risk exposure. The Safety Board recognizes that

not all excavators currently use one-call notifications systems and that there are 84 separate one-call systems operating in the United States collecting different information in

different formats. The Safety Board concludes that the one-call notification centers may

be the most appropriate organizations to collect risk exposure data on frequency of digging and data on accidents. To standardize how and what information should be collected, the Safety Board believes that the APWA, in conjunction with RSPA, should

develop a plan for collecting excavation damage exposure data and then work with the

one-call systems to implement the plan to ensure that excavation damage exposure data

are being consistently collected. The universal damage report form developed by Alberta

One-Call (appendix E) could be considered by the OCSI. Finally, the Safety Board believes that the APWA and RSPA should use excavation damage exposure data in the periodic assessments of the effectiveness of State excavation damage prevention programs

described in other safety recommendations in this report.

Accident Reporting Requirements

of RSPA

The requirements and criteria for reporting natural gas and hazardous liquid pipeline accidents are found in 49 CFR Part 191.3 and Part 195.50, respectively. A natural

gas incident report is required for (1) an event that involves release of gas causing a

death, or personal injury necessitating in-patient hospitalization, or property damage or

loss of $50,000;77 (2) an event that results in an emergency shutdown; or (3) an event that

is significant in the judgment of the operator. For hazardous liquids, an accident report is

required for any of the following conditions: (1) explosion or fire not intentionally set by

the operator; (2) loss of 50 or more barrels of liquid product; (3) escape to the atmosphere

of more than 5 barrels a day of volatile liquids; (4) death of any person; (5) bodily harm;

(6) or estimated property damage exceeding $50,000.

 77 Before 1984, $5,000 was the OPS property loss threshold for reporting natural gas and liquid

pipeline failures. In July 1984, this threshold was increased, resulting in a sharp decline in reportable line

failures after 1983.
48 Chapter 5 System Performance Measures

RSPA receives accident reports on only a small portion of the underground infrastructure, not as a result of failure to report on the part of industry, but because RSPA’s

oversight responsibilities are limited to only a portion of the gas and hazardous liquids

systems, and of that subset, accident reports are required only when reporting thresholds

are exceeded. Nonetheless, RSPA’s database is important because there are few sources

for national accident measures and because RSPA’s experience in collecting pipeline accident data can be useful for designing future databases on excavation damage.

According to the GRI study of damage prevention, gas transmission and distribution systems accident reports by RSPA account for less than 1 percent of the occurrences

of underground pipeline damage.78 Although numerous accidents and incidents do not

meet the above reporting criteria and, consequently, are not recorded by RSPA, the Safety

Board is concerned that many accidents that should be reported are not being reported

because the cost of damage is underestimated. For example, a recent university study

determined that a gas line rupture, originally reported to cost $15,000, cost substantially

more.79 Survey responses from businesses, homeowners, and emergency response units

determined that the cost of the accident, not including the cost of lost gas or legal fees

associated with ongoing litigation, was over $300,000. Because of the $50,000 reporting

threshold, this accident, based on the original damage estimate, was not required to be

reported to RSPA.

Although a determination by the operator that an incident costs less than $50,000

alleviates the operator of the requirement to report the incident to RSPA and may be a

factor in the under-reporting of accidents, estimating property damage can be difficult and

very subjective. The incident reports filed by operators ask for estimated property damage; however, little guidance is provided to operators on all costs that should be included

to ensure accurate reporting. Dollar amounts are generally assumed to represent product

loss, facility damage incurred by the operator and others, and the environmental cleanup

cost; however, the exclusion of any one of these costs could reduce the estimated damage

to below the reporting threshold. As a result, the accident would not be reported to

RSPA. The Safety Board concludes that facility operators are provided little guidance for

estimating property damage resulting from an accident, and subjective estimates of damage below the reporting threshold may account for some accidents not being reported to

RSPA when they should have been. Therefore, the Safety Board believes that RSPA

should 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.

 78 Doctor, R.H.; Dunker, N.A.; Santee, N.M. 1995. Third-Party Damage Prevention Systems. GRI95/0316. Final report, contract 5094–810–2870. Chicago, IL: Gas Research Institute. 67 p., plus

appendixes.

79 North Carolina State University, Construction Automation & Robotics Laboratory. 1996. Assessment

of the Cost of Underground Utility Damages. Raleigh, NC. 17 p., plus appendixes. The study was also the

subject of the following article: Carver, C. 1996. “Real Costs of Utility Damages Researched by NCSU.”

Underground Focus 10(6): 28. September/October.
Chapter 5 System Performance Measures 49

Accident Causes

The accident report form for hazardous liquid pipelines offers seven categories of

cause.80 For accidents reported between 1986 and 1995, three categories (corrosion, outside force damage, and other) accounted for 78 percent of the reported accidents. For

1996, RSPA data indicated that “outside force damage” was the leading cause of accidents (damage by outside force is primarily, though not exclusively, the category in which

excavation damage is placed). The second leading cause for that year was “other.” The

Safety Board has previously expressed concern that the definition of accident cause is

imprecise and that distinctions between categories of cause are vague (see appendix G).

For example, in the data for hazardous liquid pipeline accidents, pipeline accidents resulting from similar events (as described by text explanations) are categorized differently.

Accidents described as “lightning strike,” “vandalism,” “drilled into pipe,” and “bullet

hole” appear in both the “outside force damage” and “other” categories. Because excavation damage is not separately categorized, Safety Board staff conducted a systematic

review of the accidents reported to RSPA for the years 1991 through 1996 to determine

the number of excavation-related accidents (table 5–1). The review indicated no trend

toward a long-term decrease in excavation-related accidents (figure 5–1).

Numerous accident records in the databases for distribution, transmission, and

hazardous liquids systems show $0.00 for accident costs.81 This is particularly disturbing

because in one case, a damage cost of $0.00 was reported for an accident that injured 12

persons (a distribution system accident, July 1996 in Brooklyn, New York). A review of

text comments associated with the accident records indicated that most excavation

damage accidents were classified in the database as “outside force damage.” However,

there were many additional accidents classified as “outside force damage” that were not

excavation-caused and several incidents of excavation damage were mis-categorized as

“other,” “corrosion,” “accidentally caused by operator,” or “construction/operating error.”

Based on this review and previous analysis of RSPA data, the Safety Board concludes that deficiencies in RSPA accident data, particularly with respect to the cause of

accidents and a record of whether those involved in pipeline accidents participated in excavation damage prevention programs, precludes effective analyses of accident trends and

evaluations of operator performance. Although RSPA and the industry consider excavation damage to be one of the leading causes of pipeline accidents, excavation damage is

not specifically indicated on RSPA’s accident form as a separate data element. A more

useful analysis of accident data could also be performed if information were available on

 80 DOT Form 7000-1, Part D: (1) corrosion, (2) failed weld, (3) incorrect operation by operator personnel, (4) failed pipe, (5) outside force damage, (6) malfunction of control or relief equipment, (7) other—

specify. Category 7 includes cases involving excavation damage, such as backhoe dug into line, and category 5 (outside force damage) includes vandalism and lightning strikes. Excavation damage is not separately categorized.

81 Accidents with $0.00 damage are included in the database because they meet one of the other criteria

for reporting. For 1996, the three databases show 76 accidents with $0.00 damage costs.
Chapter 5 System Performance Measures 50
Chapter 5 System Performance Measures 51
52 Chapter 5 System Performance Measures

1991 1992 1993 1994 1995 1996

0

50

100

150

Hazardous liquid systems

Transmission systems

Distribution systems

Figure 5–1. Number of excavation-related accidents

for distribution, transmission, and hazardous liquid

systems, 1991–1996.

the primary, secondary, and contributing causes. The Safety Board has found through

years of accident investigations that accidents are rarely the result of one event, but rather

the consequence of a sequence or combination of events. Categories based on purpose of

the excavation (building construction, road grading, utility maintenance); type of equipment involved (backhoe, grader, road vehicle); excavator (facility owner employee, contract employee, landowner, general public); and locator (facility owner or contract

support) could provide meaningful information with which analyses of accident trends

and evaluations of operator performance could be conducted.

The Safety Board has addressed deficiencies in RSPA’s accident data on several

previous occasions.82 Most recently, in a 1996 special investigation report, the Safety

Board evaluated RSPA’s collection and analysis of accident data for petroleum product

pipelines.83 In that report, the Board concluded that RSPA’s failure to fully implement

the Safety Board’s original 1978 safety recommendations to evaluate and analyze its

accident data reporting needs has hampered RSPA’s oversight of pipeline safety.

Consequently, the Safety Board recommended that RSPA

 82 See appendix G for a list of Safety Board recommendations related to RSPA’s accident data.

83 National Transportation Safety Board. 1996. Evaluation of Accident Data and Federal Oversight of

Petroleum Product Pipelines. Pipeline Special Investigation Report NTSB/SIR-96/02. Washington, DC.

67 p. The special investigation was prompted by the ruptures of two petroleum product pipelines operated

by the same company. Both ruptures occurred within a 15-month period.
Chapter 5 System Performance Measures 53

Develop within 1 year and implement within 2 years a comprehensive plan

for the collection and use of gas and hazardous liquid pipeline accident

data that details the type and extent of data to be collected, to provide the

Research and Special Programs Administration with the capability to

perform methodologically sound accident trend analyses and evaluations

of pipeline operator performance using normalized accident data. (P-96-1)

RSPA indicated that it agreed with the Board’s recommendation and was working with

the pipeline industry to determine the value of industry’s data to RSPA.84 Industry and

RSPA have conducted workshops to review data issues and, as recommended by the

Safety Board, RSPA has obtained database information from the Federal Energy

Regulatory Commission for analysis. The Safety Board believes that given the large percentage of accidents that are caused by excavation damage and the emphasis in recent

years by industry to address and respond to these types of accidents, RSPA should, as part

of its comprehensive plan for the collection and use of gas and hazardous liquid data,

revise the cause categories on its 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.

 84 Correspondence dated August 7, 1996, from the RSPA Administrator. On January 2, 1997, the

Safety Board classified Safety Recommendation P-96-1 “Open—Acceptable Response” based on RSPA’s

response and pending a further progress report.

Conclusions 55

Conclusions

1. Full participation in excavation damage prevention programs by all excavators and

underground facility owners is essential to achieve optimum effectiveness of these

programs.

2. Many essential elements and activities of a one-call notification center have been

identified but have not been uniformly implemented.

3. Administrative enforcement has proven effective in some State excavation damage

prevention programs.

4. Pre-marking an intended excavation site to specifically indicate the area where

underground facilities need to be identified is a practice that helps prevent excavation

damage.

5. Employee qualification and training is an integral component of an effective

excavation damage prevention program, and industry has recognized the need for

employee training but has not implemented training uniformly.

6. At a minimum, excavators should formulate an emergency response plan appropriate

for the specific construction site and ensure that employees working at that site know

the correct action to take if a buried facility is damaged.

7. Although considerable progress has been made to improve State excavation damage

prevention programs, additional efforts are needed to uniformly develop and

implement programs that are most effective.

8. More research and testing is needed to determine the accuracy of depth detection by

remote locating equipment.

9. Facility maps should have a standard depiction for underground facilities that were

installed using directional boring techniques.

10. Underground facility mapping must consider the amount of detail and the accuracy of

information necessary for effective use.

11. Providing construction planners with information on the location of underground

facilities, referred to as “planning locates,” can reduce conflicts between construction

activities and existing underground facilities.

12. One-call notification centers may be the most appropriate organizations to collect

risk exposure data on frequency of digging and data on accidents.
56 Conclusions

13. Facility operators are provided little guidance for estimating property damage

resulting from an accident, and subjective estimates of damage below the reporting

threshold may account for some accidents not being reported to the Research and

Special Programs Administration when they should have been.

14. Deficiencies in the Research and Special Programs Administration’s accident data,

particularly with respect to the cause of accidents and a record of whether those

involved in pipeline accidents participated in excavation damage prevention

programs, precludes effective analyses of accident trends and evaluations of operator

performance.
Recommendations 57

Recommendations

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)
58 Recommendations

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)
Recommendations 59

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)
60 Recommendations

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)
Recommendations 61

By the National Transportation Safety Board

James E. Hall John A. Hammerschmidt

Chairman Member

Robert T. Francis II John Goglia

Vice Chairman Member

George W. Black, Jr.

Member

Adopted: December 16, 1997

Appendix A 63

Appendix A

NTSB Investigations of Accidents

Caused by Excavation Damage,

Since 1985

Date of

accident Location

NTSB accident

number

06/09/94 Allentown, Pennsylvania DCA94MP003

05/03/94 Green River, Wyoming DCA94MP002

03/23/94 Edison, New Jersey DCA94MP001

01/31/93 Allentown, Pennsylvania DCA94FP002

07/22/93 St. Paul, Minnesota DCA93MP011

06/09/93 Cliffwood Beach, New Jersey DCA93FP008

03/28/93 Reston, Virginia DCA93MP007

12/03/92 Denver, Colorado DCA93FP003

08/19/92 Lancaster,Ohio DCA92FP010

05/20/92 Rochester, Michigan DCA92FP008

01/02/92 Ontario, New York DCA92FP003

12/28/91 Santa Rosa CA DCA92FP002

12/19/91 Fountain Inn, South Carolina

(Durbin Creek)

DCA92FP001

02/05/91 Greendale, Wisconsin DCA91FP004

02/19/91 Lititz, Pennsylvania DCA91FP005

03/13/90 Blenheim, New York DCA90MP006

11/19/88 Smithtown, New York DCA91FP004

08/31/88 Green Oaks, Illinois

(Waukegan)

DCA88FP015

12/18/87 Austin, Texas DCA88FP002

11/12/87 Kalkaska, Michigan DCA88FP001

08/05/87 Wilmington, North Carolina DCA87FP014

06/11/87 Centerville, Virginia DCA87FP011

12/06/86 Elk City. Oklahoma DCA87FP005

10/16/86 Wausau, Wisconsin DCA87FP003

10/13/86 Boise City, Oklahoma DCA87FP002

09/15/86 Bellvue, Nebraska DCA86FP017

07/06/86 New Castle, Oklahoma DCA86FP013

04/24/86 Elgin, Illinois DCA86FP012

03/13/86 Chicago Heights, Illinois DCA86FP011

02/12/86 Fort Worth, Texas DCA86FP010

02/04/86 Crystal City, Mississippi DCA86FP007

12/24/85 Medley, Florida DCA86FP006

12/06/85 Derby, Connecticut DCA86FP004

04/27/85 Beaumont, Kentucky DCA85MP011
64 Appendix B

Appendix B

Excerpts From Federal Regulations

Pertaining to Excavation

Minimum standards for excavation damage prevention programs for operators of gas

pipelines (from Title 49 Code of Federal Regulations):
Appendix B 65

Minimum standards for excavation damage prevention programs for operators of

hazardous liquid pipelines (from Title 49 Code of Federal Regulations):
66 Appendix B

Summary of selected OSHA requirements relating to excavation (from Title 29 Code of

Federal Regulations):

Paragraph 1926.650(b) defines competent person as one “who is capable of

identifying existing and predictable hazards in the surroundings, or working

conditions that are unsanitary, hazardous, or dangerous to employees, and who has

authorization to take prompt corrective measures to eliminate them.” (The

preamble to the final rule for 26 CFR 1926 advises that a “competent person”

must have had training in, and be knowledgeable about, soils analysis, the use of

protective systems, and the requirements of standard 1926.)

Paragraph 1926.651(b) requires that the estimated location of utility

installations, including gas lines, must be determined before opening an

excavation. Consistent with local time constraints, such as those in Pennsylvania

Act 38 and before beginning an excavation, excavators are required to contact

utility companies/owners, advise them of the proposed work, and ask them to

establish the locations of underground installations. When the excavator is

approaching the estimated location of a marked buried facility, he is required to

determine the exact location by safe and acceptable means. While the excavation

is open, underground installations must be protected, supported, or removed as

necessary to safeguard employees and people that live or work in the vicinity.

Paragraph 1926.651(i) requires protection of adjacent structures by support

systems, such as shoring, if the excavation operations endanger them.

Paragraph 1926.651(k) requires daily inspections of excavations when employee

exposure can be reasonably anticipated of the adjacent areas and of protective

systems by a competent person for evidence of a situation that could result in

cave-ins, failure of protective systems, hazardous atmospheres, or other hazardous

conditions. The paragraph also requires that employees be removed from any

hazardous condition until proper corrective action has been taken.

Paragraph 1926.652(a) requires protection of employees from cave-ins when in

excavations 5 feet deep or more. The protective system may be one of several

described in the regulation, such as sloping, benching, or shoring.
Appendix C 67

Appendix C

Characteristics of Current State Laws

on Excavation Damage Prevention

The characteristics in this appendix were reproduced from the following publication:

American Public Works Association. 1997. One-Call Systems International

Directory 1997–1998 and Excavator’s Damage Prevention Guide. Kansas City,

MO. 45 p. (p. 31–43).
68 Appendix C
Appendix C 69
70 Appendix C
Appendix C 71
72 Appendix C
Appendix C 73
74 Appendix C
Appendix C 75
76 Appendix C
Appendix C 77
78 Appendix C
Appendix C 79
80 Appendix C
Appendix D 81

Appendix D

Reports of Workshop Groups

on Excavation Damage Prevention

The reports in this appendix were reproduced from the following publication:

National Transportation Safety Board. 1995. Proceedings of the Excavation

Damage Prevention Workshop; 1994 September 8–9; Washington, DC. Report of

Proceedings NTSB/RP–95/01 (p. 175–183). Washington, DC. Appendix A.
82 Appendix D
Appendix D 83
84 Appendix D
Appendix D 85
86 Appendix D
Appendix D 87
88 Appendix D
Appendix D 89
90 Appendix D
Appendix E 91

Appendix E

Example of

Universal Damage Report Form

The form shown in this appendix was developed by the Alberta One-Call Corporation in

Calgary, Alberta, Canada.
92 Appendix E
Appendix F 93

Appendix F

Industry Practices and Procedures

for Excavation Damage Prevention

The guidelines in this appendix were reproduced from the following publication, with the

permission of the National Utility Locating Contractors Association:

National Utility Locating Contractors Association. 1997. Excavation Practices and

Procedures for Damage Prevention: A Guide for Protection of Underground

Facilities. Spooner, WI. 8 p.
94 Appendix F
Appendix F 95
96 Appendix F
Appendix F 97
98 Appendix F
Appendix F 99
100 Appendix F
Appendix F 101
102 Appendix F
Appendix F 103
104 Appendix G

Appendix G

NTSB Safety Recommendations

Related to RSPA Accident Data

Safety Recommendation No.: P-78-58

Date Issued: October 15, 1978

Recipient: Research and Special Programs Administration

Status and Date Status Assigned: Closed—Superseded, September 9, 1987

Recommendation:

Publish a plan that describes how the OPSO will use accident report data to

formulate safety regulations and to develop a safe service life model for pipelines.

Safety Recommendation No.: P-78-59

Date Issued: October 25, 1978

Recipient: Research and Special Programs Administration

Status and Date Status Assigned: Closed—Unacceptable Action, May 23, 1989

Recommendation:

Redesign the Liquid Pipeline Accident Reporting System to include data similar to

that collected in the Natural Gas Accident Reporting System.

Safety Recommendation No.: P-78-60

Date Issued: October 25, 1978

Recipient: Research and Special Programs Administration

Status and Date Status Assigned: Closed—Unacceptable Action, May 23, 1989

Recommendation:

Provide clear instructions and definitions to ensure the accuracy and consistency of

the data recorded on the liquid pipeline accident report forms.
Appendix G 105

Safety Recommendation No.: P-78-61

Date Issued: October 25, 1978

Recipient: Research and Special Programs Administration

Status and Date Status Assigned: Closed—Unacceptable Action, May 23, 1989

Recommendation:

Computerize the redesigned Liquid Pipeline Accident Reporting System. Include the

capability to (a) compute the historical accident/leak rate-per-mile of pipe for each

carrier as well as the nationwide rate; (b) make periodic comparisons of each

carrier’s accident/leak rate against the nationwide accident/lead rate; (c) compute and

plot selective accident/leak rates based on pipeline parameters such as age, specified

yield strength, depth of cover, product transported, etc.; (d) selectively retrieve and

summarize accident/leak data pertaining to any given accident or classification of

accidents; and (e) produce summarized reports reflecting the above-listed

information.

Safety Recommendation No.: P-78-62

Date Issued: October 25, 1978

Recipient: Research and Special Programs Administration

Status and Date Status Assigned: Closed—Unacceptable Action, April 4, 1979

Recommendation:

Conduct audits of the completed liquid pipeline accident reports to ensure that

mandatory data are provided.

Safety Recommendation No.: P-80-61

Date Issued: August 20, 1980

Recipient: Research and Special Programs Administration

Status and Date Status Assigned: Closed—Unacceptable Action, May 31, 1989

Recommendation:

Develop and publish for public comment a formal data analysis plan for the pipeline

data system.
106 Appendix G

Safety Recommendation No.: P-80-62

Date Issued: August 20, 1980

Recipient: Research and Special Programs Administration

Status and Date Status Assigned: Closed—Unacceptable Action, October 7, 1981

Recommendation:

Expedite the proposed creation of an Office of Regulatory Planning and Analysis and

define responsibilities for developmenet and management of a pipeline data analysis

plan.

Safety Recommendation No.: P-80-63

Date Issued: August 20, 1980

Recipient: Research and Special Programs Administration

Status and Date Status Assigned: Closed—Unacceptable Action, March 17, 1986

Recommendation:

Postpone promulgation of proposed, revised pipeline data forms until development

of a data analysis plan and coordination of the forms with the plan.

Safety Recommendation No.: P-80-64

Date Issued: August 20, 1980

Recipient: Research and Special Programs Administration

Status and Date Status Assigned: Closed—Reconsidered, October 7, 1981

Recommendation:

Develop explicit directions for completion of the present data forms to improve the

quality of the information collected on these forms. Assure that terms not universally

accepted across the pipeline industry are defined.

Safety Recommendation No.: P-80-65

Date Issued: August 20, 1980

Recipient: Research and Special Programs Administration

Status and Date Status Assigned: Closed—Acceptable Alternate Action,

March 17, 1986

Recommendation:

Train existing personnel to more effectively validate incoming leak report forms.