# U.S. DOT/PHMSA - Report to Congress

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- **title:** U.S. DOT/PHMSA - Report to Congress
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- **agency:** Pipeline and Hazardous Materials Safety Administration
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- **summary:** Assuring the Integrity of Gas Distribution Pipeline Systems A Report to the Congress May 2005 Submitted by: Office of Pipeline Safety Pipeline and Hazardous Materials Safety Administration U.S. Department of Transportation Table of Contents Executive Summary………………………………………………………………………….1 1. Program Overview………………………………………………………………………..2 2. Regulation of Distribution Systems and the Role of State/Federal Governments………..4 3. The Gas Distribution Safety Baseline…………………………………………………….5 Diversity of Operators………………………………………………………………..5...
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<<<PAGE 1>>>

Assuring the Integrity of Gas Distribution Pipeline Systems
A Report to the Congress
May 2005
Submitted by:
Office of Pipeline Safety
Pipeline and Hazardous Materials Safety Administration
U.S. Department of Transportation

<<<PAGE 2>>>

Table of Contents
Executive Summary………………………………………………………………………….1
1. Program Overview………………………………………………………………………..2
2. Regulation of Distribution Systems and the Role of State/Federal Governments………..4
3. The Gas Distribution Safety Baseline…………………………………………………….5
Diversity of Operators………………………………………………………………..5
Diversity of Infrastructure……………………………………………………………7
Existing Regulations and Practices…………………………………………………..7
Insights from Incident Data…………………………………………………………..9
Innovative Practices…………………………………………………………………11
Monitoring the Effectiveness of Actions……………………………………………11
4. Evaluation of Applicability of Transmission IM Program and Practices………………..12
Integrity Management Elements…………………………………………………….12
Applicability to Distribution Pipeline Systems……………………………………...12
Identifying High Consequence Areas………………………………………..12
a. Hazardous liquid pipelines……………………………….………….12
b. Gas transmission pipelines…………………………………………..13
c. Gas distribution pipelines……………………………………………13
Assessing Pipeline Integrity………………………………………………….14
a. In-line Inspection…………………………………………………….14
b. Pressure testing………………………………………………………14
c. Direct Assessment……………………………………………………15
Applicability of Current IMP Practices………………………………………………17
5. Principles Guiding the PHMSA Approach………………………………………………..17
6. Plan and Schedule for Defining and Implementing Distribution Integrity Management
Requirements…………………………………………………………………………………19
7. Options Being Considered………………………………………………..……………….21
Specific Attention to Excess Flow Valves……………………………………………25
8. Conclusion………………………………………………………………………………...26
Attachments
1. NAPSR State Survey Results -- State Requirements beyond Federal Regulations
Gas Distribution Systems
2. Summary of Allegro Report – Safety Incidents on Natural Gas Distribution Systems:
Understanding the Hazards, April 2005
3. NARUC Resolution on Distribution Integrity Management, February 16, 2005
4. Position of the American Public Gas Association on Distribution Integrity Management
5. PHMSA/OPS Phase 1 Action Plan
List of Figures
1. Distribution systems subject to 49 CFR 192………………………………………………..6
2. Relationship among Federal Requirements, Standards or Guidelines, and State
Requirements…………………………………………………………………………………23
3. Example of High-level Federal Performance Requirements……………………………...24
i

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Acronyms
AGA – American Gas Association
AGF – American Gas Foundation
APGA – American Public Gas Association
CFR – Code of Federal Regulations
DA – Direct Assessment
DOT – Department of Transportation
EIA – Energy Information Administration
EFV – Excess Flow Valve
FR – Federal Register
ILI – In-line inspection
IM – Integrity Management
IMP – Integrity Management Plan
LP – Liquid propane
NAPSR – National Association of Pipeline Safety Representatives
NARUC – National Association of Regulatory Utility Commissioners
OPS – Office of Pipeline Safety
PHMSA – Pipeline and Hazardous Materials Safety Administration
USC – United States Code
ii

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A Report to the Congress: Assuring the Integrity of Gas 1
Distribution Pipeline Systems
Executive Summary
The FY 2005 Conference Committee on Appropriations asked1 the Department of
Transportation’s (DOT) Pipeline and Hazardous Materials Safety Administration (PHMSA)
Office of Pipeline Safety (OPS) to submit a report detailing the extent to which integrity
management plan elements may be applied to gas distribution pipeline systems to enhance
safety. “Integrity management” refers to programs that OPS has required of hazardous liquid
and gas transmission pipeline operators, through rules promulgated within the last five years.
Integrity management requirements have not yet been established for gas distribution pipeline
systems. The Department of Transportation’s (DOT) Inspector General recommended that
OPS take this action in testimony before the Congress in 2004.2
The principal focus of the existing integrity management regulations for pipelines is to
identify the portions of the pipeline system that pose the most risk; to inspect the physical
condition of those portions of the pipelines; and to repair any defects that could challenge the
pipeline integrity. The fundamental principles of integrity management require:
understanding the infrastructure and the risks it poses, and then taking actions to address those
risks. There are significant differences in the design of gas distribution pipeline systems
compared to the pipelines subject to current integrity management regulations. These include
pipe size, operating pressure, materials, and the large number of branches and connections in
distribution systems. These design differences significantly limit the applicability of the
inspection techniques currently in use for those pipelines to distribution pipeline systems.
The challenge is to develop appropriate methods to apply the principles of integrity
management to enhance the safety of distribution pipeline systems, while remaining mindful
of costs and service disruptions and their potential impact on consumers.
Gas distribution pipelines, those that deliver gas directly to consumers, are almost entirely
under the regulatory oversight of state agencies. OPS has implemented a program jointly with
its state partners and a broad range of stakeholders, to identify means appropriate to
distribution pipelines to focus attention on areas that pose the highest risk and to better assure
the integrity of those portions of the distribution systems, in other words, integrity
management.
The first phase of the program is to be completed in 2005 and will identify the nature of
requirements that might be imposed and any additional guidance or consensus standards that
might be needed to assist operators in implementing any integrity management requirements.
This phase will include consideration of a multi-faceted set of potential approaches, including
regulations and guidance, but will also consider a national education program, development of
new inspection technologies, and legislative models that states could adopt. The second
phase, to begin in January 2006, will include development of appropriate requirements by
OPS and preparation of guidance/standards by appropriate bodies.
1 House of Representatives Report 108-792, November 20, 2004.
2 “Progress and Challenges in Improving Pipeline Safety,” Statement of the Honorable Kenneth M. Mead,
Inspector General, Department of Transportation, before the Committee on Energy and Commerce,
Subcommittee on Energy and Air Quality, U. S. House of Representatives, July 20, 2004.

<<<PAGE 5>>>

A Report to the Congress: Assuring the Integrity of Gas 2
Distribution Pipeline Systems
1. Program Overview
The DOT Inspector General, in testimony before Congress in July 2004,3 recommended that
OPS should define an approach for requiring operators of distribution pipeline systems to
implement some form of integrity management or enhanced safety program with elements
similar to those required in hazardous liquid and gas transmission pipeline integrity
management programs. The Appropriations Committee asked OPS “to report to the House
and Senate Committees on Appropriations by May 1, 2005, detailing the extent to which
integrity management plan [IMP] elements may be applied to the natural gas distribution
pipeline industry in order to enhance distribution system safety”.4
Industry and government have long been committed to the safe operation of the Nation’s 1.9
million miles of natural gas distribution pipelines. Building on the existing set of
requirements, regulators and pipeline operators continue to examine natural gas distribution
practices to understand the most effective approaches to improving the integrity and safety of
these systems.
During the past five years, OPS (as part of PHMSA) has promulgated regulations designed to
improve the integrity of liquid and gas transmission pipelines. Together with our State
partners, PHMSA has undertaken inspection of the programs by which operators are
implementing these regulations. Implementation of these regulations has led both to
improvements in the operators’ knowledge of their pipelines, and to identification and repair
of thousands of defects in these pipelines. OPS also regulates distribution pipeline systems.5
Pursuant to agreements among OPS and the States, state inspectors perform most of the
inspection and enforcement of the pipeline safety regulations on gas distribution systems.
OPS ensures that State programs provide safety oversight in compliance with the Federal
pipeline safety regulations.
OPS and our State partners developed a program through which we will thoroughly
reexamine means for strengthening the safety of distribution pipeline systems. This program
will address the three elements of the strategy described by the DOT Inspector General: (a)
understanding the infrastructure; (b) identifying and characterizing the threats; and (c)
determining how best to manage the known risks (prevention, detection and mitigation).
These three elements are essentially the same as those underlying the transmission pipeline
integrity management regulations. The program will provide the basis for establishing
integrity management requirements for distribution pipeline systems. These requirements
must be different than those that have been applied to hazardous liquid and gas transmission
3 Ibid.
4 House of Representatives Report 108-792, November 20, 2004.
5 Gas transmission pipelines transport gas from areas where it is produced to areas where it is consumed. These
pipelines are generally steel, of large diameter, operate at high pressures, and traverse long distances, sometimes
more than 1,000 miles. Distribution pipeline systems are the network of pipes in communities that provide gas
directly to consumers. They consist of small diameter pipelines, operating at low pressure, and constructed of a
variety of materials. Distribution pipelines exist as a network with many branches in short distances (e.g., a
service line connection for each house on a city street). The differences between the two types of pipelines can
lead to a need to use different approaches to assuring safety, as described in this report.

<<<PAGE 6>>>

A Report to the Congress: Assuring the Integrity of Gas 3
Distribution Pipeline Systems
pipelines, because the models and tools prescribed by those regulations have only very limited
applicability to distribution pipeline systems.
The program presented in this Report was designed to identify opportunities for improving the
safety of distribution pipeline systems. Our analysis of the past few years of data identified
that in order to address safety threats to distribution pipelines, there are a number of target
audiences that PHMSA needs to involve in developing strategies to reduce these threats.
Accordingly, OPS is involving a larger number of key stakeholder groups than contacted in
the past, including State and Federal regulators, representatives from the spectrum of
distribution operators, interested members of the public, and representatives of our Nation’s
fire service. These participants are organized into work/study groups that will gather and
analyze data to help focus the effort and ultimately identify options for attaining improved
safety. In addition, OPS will be posting information on a public web site as the program
activities progress, to offer an opportunity for other interested members of the public to
comment.
OPS organized the program in two major phases. During the remainder of 2005 (Phase 1)
work/study groups will gather and analyze data, and develop the elements of a safety
improvement program. During the following year (Phase 2) OPS and pipeline standards
development organizations (if needed) will work to develop requirements, guidelines and
standards that will be implemented using some combination of four options favored by a
consensus of the stakeholder group.
• The first option is a high level, risk-based, performance-oriented Federal regulation.
• The second option is supplemental information through one or more guidelines or
national consensus standards describing choices on how the spectrum of distribution
pipeline operators might apply fundamental risk-based principles to achieve the
desired improvements. States would then have the opportunity to draw on the
standards and guidance to promulgate regulations describing how the unique set of
operators they regulate should implement improvements satisfying the Federal
requirements.
• Third is a structured nation-wide education program on preventing excavation
damage, focused on the new 811 one-call program.
• The final option is development of innovative safety technologies capable of
producing observable safety improvements.
The requirements that may result from this program could prove expensive for operators to
implement. The view of an executive steering group6 was that it is important to consider all
costs related to new efforts to prevent and mitigate distribution line incidents together, in
order to assure the most cost-effective solution. Thus, the group emphasized the importance
of evaluating all options for preventing, detecting and mitigating threats to public safety
consistently. For example, the group indicated its preference that use of excess flow valves
(EFVs) as a means of mitigating the impact of severed gas distribution lines should be
6 See Section 6 for a description of the groups involved in the Action Plan

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A Report to the Congress: Assuring the Integrity of Gas 4
Distribution Pipeline Systems
considered as part of the overall distribution safety improvement program, rather than being
addressed in a separate Federal mandate.
2. Regulation of Distribution Systems and the Role of State/Federal Governments
The principal authority for regulating the safety of gas distribution pipeline systems is
exercised by State governments. Under 49 USC 60105 and 60106, States may exercise
jurisdiction if their pipeline safety programs are certified by the DOT or if they enter into an
agreement with DOT absent certification. At this time, all States except Alaska and Hawaii
exercise safety jurisdiction under these provisions. States have a variety of ways in which
they can oversee distribution pipeline safety. They can simply mirror the Federal pipeline
safety program. They can impose additional requirements, beyond the Federal minimum.
They can engage in special oversight programs with individual operators or groups of
operators. Finally, they can provide incentives for safety improvements, often through their
rate-setting authority.
The Federal government has ultimate responsibility in regulating intrastate distribution
pipeline operators. The Federal standards in 49 CFR Part 192 establish a minimum set of
safety requirements that all states must implement. The DOT also collects data concerning
distribution system mileage, incidents that occur on systems, their leak repair experience and
other information about the size, age and material(s) of construction of their distribution
piping. Initial consideration of an approach to integrity management for distribution pipeline
systems will seek to identify changes that could be made in DOT data collection that would
help improve the ability of State and Federal regulators to analyze and more clearly
understand distribution system’s operating experience. The Office of Pipeline Safety will
define further what improvements are needed and will determine if changes to its data
collection forms are needed.
OPS provides funding for the operation of State pipeline safety programs through a grant
program that funds States’ oversight efforts. OPS has, in the past, identified emphasis areas
for State focus in their oversight programs. These emphasis areas have included content of
state regulations, pursuit of special initiatives, approaches to inspection of operators, and data
collection and reporting. OPS can adjust its criteria for state funding grants to assure that
appropriate emphasis exists in each State’s program.
One area for special grant allocation resources is damage prevention – being proactive to
reduce the likelihood that distribution pipelines will be damaged during excavation work.
(This is a principal threat to the integrity of distribution pipelines).
OPS is also engaged in work with state fire marshals, and has included a representative of this
community in the distribution integrity management program. Representatives of public
interest groups are also involved in helping to define the appropriate approaches to assuring
distribution system integrity. This inclusiveness demonstrates the willingness of OPS and
States to go beyond previous efforts to improve the assurance of distribution pipeline system
safety. The OPS will also seek other input through posting documents related to this program
on a web site.

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A Report to the Congress: Assuring the Integrity of Gas 5
Distribution Pipeline Systems
It is appropriate that the principal actions for regulating distribution pipeline safety rest with
the States. States need to balance safety and affordability. They need to assure that the
particular needs of their citizenry are fulfilled. They also need to assure that the safety
standards being applied are appropriate for the unique environment in which gas distribution
occurs. Distribution pipeline systems are limited in geographic scope. The environment in
which they operate significantly affects the safety issues that they face. Factors such as
weather (dry/wet, hot/subject to freezing), soil conditions (corrosivity), and the local economy
(significant construction and excavation activity) can significantly shape the threats affecting
individual distribution operators and the actions necessary to address those threats. Proximity
to gas producing regions also can be important, as natural gas that is distributed near
production areas may be subject to little processing and may contain more contaminants, with
potential to affect system integrity, than gas that is processed for long-distance transportation.
States must have flexibility to deal with their local circumstances. It would be both
ineffective and inefficient, for example, to impose requirements intended to address frost
heave damage in the desert southwest. Integrity management requirements for distribution
pipeline systems will be structured in a manner that allows States the necessary flexibility in
implementation.
3. The Gas Distribution Safety Baseline
In order to know what opportunities there are to enhance distribution pipeline safety, we must
first examine where and how operators are performing today.
There is very significant diversity among gas distribution pipeline operators in the United
States. The size and technical depth of operators of distribution pipeline systems, the nature
of the systems they operate, the requirements they must meet, and the practices that they use
to assure safety all vary widely. An understanding of these differences, and the current
approach to sharing and using practices that go beyond the regulations, i.e., the “baseline”
level of program management, will be useful in understanding the approach being taken to
enhance distribution integrity management.
Diversity of Operators
Operators of distribution pipeline systems subject to OPS/State safety regulation are of four
different types:
• Master meter systems (e.g., trailer parks, individual multi-occupancy buildings)
• Publicly owned (e.g., town/city/county) municipal utilities
• Investor-owned utilities
• Propane gas distribution systems
The order within this list represents the prevalence of each type of operator. There are
approximately 1,000 publicly owned utilities delivering gas to consumers in the United States.
By contrast, there are approximately 250 investor-owned utilities engaged in this business.

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A Report to the Congress: Assuring the Integrity of Gas 6
Distribution Pipeline Systems
There are several thousand master meter operators and a few hundred liquid propane (LP) gas
systems that are subject to the safety regulations in 49 CFR Part 192.
Figure 1 - Distribution systems subject to 49 CFR 192
(Prepared by APGA from E IA data)
# of systems
500
450
400
350
300
250
200
150
100
50
0
438
354
Municipal
Investor-owned
96
59 69
50
35
20
6 0
10
< 100 100-1000 1000-10000 10000-100000 100000-1 million > 1 million
# of customers (from EIA Form 176)
Note: EIA does not maintain data on the number of customers served by master meter systems or liquid propane
(LP) gas systems. There are several thousand master meter operators, the vast majority of which serve less than
100 customers. There are approximately 200 LP gas systems most of which also serve less than 100 customers.
Within each of these groups, the size of individual operators also varies widely, as shown in
Figure 1. Publicly-owned utilities tend to be smaller, with a majority serving less than 1,000
customers. In general, investor-owned utilities tend to be larger, with slightly over 100
companies serving more than 100,000 customers each. There are examples, though, of
publicly owned utilities serving 100,000 customers and of investor-owned companies serving
less than 1,000. The variability makes it difficult to generalize regarding these groups. The
particular circumstances of each operator must be taken into account.
Master meter operators are businesses such as apartment complexes, or mobile home or trailer
parks, or are government entities like housing authorities and universities that receive gas
from an outside supplier and distribute it via pipelines located within their facilities. These
operators are generally small, with a large majority serving fewer than 100 customers.
Distribution of gas, or operation of the distribution systems, is not their principal business.
Propane system operators subject to pipeline regulation are also small. Propane used in
individual installations, such as a rural farm with its own propane tank, is not subject to
regulation as a pipeline system. Propane systems become subject to regulation when they
distribute gas, by pipeline, to 10 or more customers. The large majority of these systems
likely serve fewer than 100 customers.

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A Report to the Congress: Assuring the Integrity of Gas 7
Distribution Pipeline Systems
Diversity of Infrastructure
The pipeline systems operated by these operators are also subject to much variation.
Natural gas has been distributed by pipeline in some areas for over a hundred years. Pipeline
systems in these areas were originally small, serving a few customers. These systems merged
as larger distribution companies were formed. The materials in use in some of these systems
reflect older (e.g., cast iron, copper, bare steel) as well as newer (e.g., polyethylene plastic and
cathodically protected coated steel) technology.
In other areas, distribution of natural gas by pipeline is a relatively new phenomenon. In
some rural areas, for example, gas may not have been available until a transmission pipeline
was routed into the vicinity. Then, municipalities or distribution companies may have created
a distribution system to bring natural gas service to customers for whom it was previously
unavailable. Systems of this nature tend to be relatively uniform in age and type of materials,
but the threats to integrity (such as electrical interference from other buried substructures and
localized flooding or vehicular traffic patterns) may still vary from one location to another.
Additional diversity will likely be introduced as systems age, new customers are added, and
portions of the original systems are replaced.
Individual master meter systems and propane systems tend to be relatively uniform due to
their small size and limited geographical extent.
Existing Regulations and Practices
The Federal pipeline safety standards in 49 CFR Part 192 provide a common base of
requirements applicable to distribution pipeline systems. These standards address design,
construction and operation of pipeline systems as well as requirements affecting inspection,
maintenance, repair and testing and also qualification of pipeline operations personnel. States
are required to adopt these standards as one of the criteria for certifying their pipeline safety
programs or for entering into an agreement with OPS to exercise safety jurisdiction. States
can, and do, impose additional requirements where appropriate.
The National Association of Pipeline Safety Representatives (NAPSR) is an organization
consisting of the senior regulatory program manager from each State that exercises pipeline
safety jurisdiction. NAPSR recently conducted a survey of its members to identify the extent
of additional State requirements that go beyond Part 192. The survey identified that most
States impose some additional requirements. A majority impose stricter criteria for reporting
incidents and/or requires that operators notify the regulator of construction or testing that
would provide an opportunity for the regulator to examine the pipeline and observe safety-
significant work. These type of requirements reflect the close oversight relationship that
exists between most state regulatory programs and the operators they regulate. State
regulators generally interact routinely with operators under their jurisdiction, and therefore
know their systems and personnel. States are actively engaged, on a daily basis, in overseeing
safe operations. Additionally, approximately 25 percent of the States impose requirements for
leak surveys beyond those required in Part 192.

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A Report to the Congress: Assuring the Integrity of Gas 8
Distribution Pipeline Systems
The NAPSR survey also identified that approximately 65 percent of States have a program to
replace some types of distribution piping. This may include cast iron pipe, uncoated and
unprotected steel pipe, or certain types of plastic pipe that have been found to be subject to
deterioration in service. The replacement programs vary in scope. In some cases, they
involve all (or nearly all) of the operators in a State. In other cases, they may involve
individual operators and may have been initiated as a result of an incident or event that
highlighted problems associated with the aging material.
A summary of the NAPSR survey results is included as Attachment 1 to this report.
In addition to the NAPSR survey, OPS contacted several larger investor-owned utilities to
obtain information about their safety practices that exceed minimum regulatory requirements.
The operators surveyed, all of which serve mid- to large-sized cities, all reported that they use
risk evaluation to help direct work on their pipelines. This supports a conclusion of the
American Gas Foundation (AGF) that 82% of companies they surveyed use risk control
practices.7 Use of risk models is not currently required of distribution system operators.
Neither OPS nor States have audited these models or their application. We therefore cannot
comment yet on the thoroughness of the approaches used, but note with satisfaction that the
concept of using an estimate of risk to manage safety activities is becoming widely prevalent.
OPS’ discussions also identified that the larger operators all had pipe management programs
that included replacing portions of their system: where problems had been experienced
identifying materials susceptible to failure; where certain construction practices potentially
leading to problems may have been used; that include their older pipelines; or based on
estimated risk. Again, this reinforces the AGF conclusion that 65% of surveyed companies
had replacement programs.8 (It should be noted that replacement of pipe in highly built-up
urban areas can be difficult due to the number and complexity of buried infrastructure
facilities and the difficulty of working in the urban environment.)
The operators contacted by OPS also perform leak surveys more frequently, based on unique
operating conditions, than would be required by regulations and implement special practices
to reduce third party damage.
Most of the operators contacted by OPS also reported that they have elected to install excess
flow valves (EFV) for new and replacement services, which goes beyond the regulatory
requirement that customers be apprised of the availability of EFVs and that they be installed if
the customer agrees to pay for them.
The most prevalent safety practice followed by distribution system operators that is not
required by Part 192 is membership in damage prevention programs, most often referred to as
“one-call” programs. The AGF reports that over 95 percent of operators belong to such
7 American Gas Foundation, “Safety Performance and Integrity of the Natural Gas Distribution Infrastructure”,
January 2005, p. 5-11.
8 Ibid, p. 5-13.

<<<PAGE 12>>>

A Report to the Congress: Assuring the Integrity of Gas 9
Distribution Pipeline Systems
programs.9 Most states require gas utilities to belong to one-call programs. The breadth of
participation in these activities provides a basis to presume that excavation damage incidents
can be reduced. However, unfortunately, these incidents continue to occur. They are
undoubtedly less prevalent than they would be in the absence of one-call programs, but they
still represent a threat to distribution pipeline systems. This program will specifically include
a review of industry practices and other approaches to prevent or reduce damage to identify
ways in which their effectiveness can be improved.
Insights from Incident Data
The principal source of information available about distribution pipeline system safety and
integrity is the data resulting from incident reports submitted to OPS. These reports are filed
by operators, pursuant to 49 CFR 191.9, and include events occurring on jurisdictional
pipelines that involve either: 1) a death or personal injury necessitating in-patient
hospitalization; 2) estimated property damage, including cost of gas lost, of the operator or
others, or both, of $50,000 or more; or 3) events that are significant, in the judgment of the
operator, even if neither of the other criteria is met or exceeded.
OPS changed its incident report form in 2004 to require that the cause of incidents be reported
more precisely. All incidents reported prior to that time were attributed by the reporting
operator to one of five major causes, one of which was “other.” Using the revised forms,
operators identify one of seven major causes, which are further subdivided into 25 second-
level causes. This change is intended to improve our understanding of the factors that result
in gas pipeline incidents.
The set of incident data submitted by operators represents significant problems that occur on
the pipeline. It does not include all events involving or exacerbated by natural gas from
distribution pipeline systems. For example, problems with an appliance in a customer’s home
could result in an accumulation of gas, an explosion, and fire, potentially resulting in injury or
death. Although the media may report such events as gas pipeline incidents, they are not.
OPS has no regulatory authority over customer-owned piping or gas appliances, and operators
are not required to report such events to OPS. Customer piping within homes and businesses
is regulated by local building codes, often based on the National Fuel Gas Code or other
model codes.
There have been two recent studies that considered recent distribution incident experience.
One was conducted by the AGF, under the oversight of a committee formed of representatives
from AGF members and state pipeline safety regulators. The results of this study were
reported in “Safety Performance and Integrity of the Natural Gas Distribution Infrastructure,”
published by AGF in January 2005. The other was performed by Allegro Energy Consulting,
in late 2004, under contract to OPS.
The AGF study covered the period from 1990 to 2002. During that period, AGF found a
statistically significant downward trend in “serious” incidents, defined as those involving a
9 Ibid, p. 5-12.

<<<PAGE 13>>>

A Report to the Congress: Assuring the Integrity of Gas Distribution Pipeline Systems
10
death or injury. (AGF chose to focus on these incidents because the reporting criteria are not
as subjective as “significant to the operator” nor do local economic factors or inflation affect
reporting of an event wherever or whenever it occurs.) The AGF concluded there were
approximately 1.6 serious incidents per 100,000 miles of distribution pipeline during 2002.
The AGF study identified that nearly half of the serious incidents occurring during the study
period were a result of outside force damage. The only other cause category contributing to
more than 10 percent of serious incidents was “other” which was responsible for almost 27
percent.
The Allegro study re-evaluated five years of incident report data (1999-2003) to re-classify
them to the new cause categories. This was accomplished by reviewing the narrative
description of the incident that the operator provided when submitting the original report.
Allegro considered 634 incidents reported in the five-year period. One third of them involved
death or injury, i.e., would have been considered “serious” incidents by the AGF study.
Nearly one half were reported due to the cost of damages alone. Six percent of the incidents
apparently did not meet any of the reporting criteria, but they were still retained in the Allegro
analysis.
Allegro’s re-classification was successful in reducing the number of incidents for which the
cause could not be attributed from the 27 percent noted in the AGF study to 12 percent.
Allegro further found that a large majority of the incidents (67%) were caused by outside
force damage. The new cause categories permitted Allegro to break the outside force damage
category down into several components. Thirty-eight percent of the incidents were caused by
excavation and mechanical damage (the vast majority caused by third parties), but 29 percent
were caused by other sources of outside force. This new category included two major
components: “fire first” and vehicle damage, each representing 11 percent of the total number
of incidents.
The fire first events represent incidents in which a building was on fire and the operator
responded, but the fire was not caused by a gas leak. In many cases, the gas supply system in
the building is compromised or damaged by the fire and contributes to its intensity until the
gas can be shut off. Fire first incidents are not caused by problems in the gas distribution
system and cannot be addressed in a distribution integrity management program.
The vehicle-related events represent incidents in which a vehicle impacts a portion of the
pipeline system, often the above-ground meter assembly. The accidents resulted from
multiple causes, including drivers operating their vehicles while intoxicated and unattended
vehicles rolling into the pipeline system. Allegro found that this category of incidents, while
representing 11 percent of all incidents, involved 25 percent of the fatal incidents over the
period studied. Thus, these data tell us that 1 out of 4 of the fatal incidents during this period
could not have been prevented by any preventive action taken on the pipeline. Reducing the
number of these incidents is likely to require actions that affect persons not under the
regulatory jurisdiction of OPS or State pipeline regulatory authorities, i.e., vehicle operators.
A summary of the Allegro report is included as Attachment 2.

<<<PAGE 14>>>

A Report to the Congress: Assuring the Integrity of Gas Distribution Pipeline Systems
11
Innovative Practices
The American Gas Association (AGA) each year sponsors groups from among its members to
identify innovative practices that they employ to improve operational performance and safety.
These groups typically evaluate approximately five topic areas (e.g., damage prevention, main
and service replacement, system reliability). In each area, practices of member companies are
shared, innovative practices are identified, and the information is exchanged with participants
at a roundtable forum. Detailed information is available only to companies that have
participated in the groups.
These forums serve a useful purpose and can contribute to expanding the understanding and
application of innovative practices. This expansion can occur among participants, which are
generally the larger, investor-owned companies. The results of these efforts are not available
to operators that do not directly participate in the program, particularly publicly-owned
operators that are not usually members of AGA.
OPS believes that these activities have a positive impact on the reduction of incidents
disproportionate to the percentage of operators that participate. There are two reasons for
believing this: the large-operator participants operate a much larger percentage of the total
distribution pipeline mileage than their numbers might suggest; and smaller operators,
particularly those with only a few persons on staff and a limited amount of pipeline mileage,
generally have much better detailed knowledge of their systems and the issues that affect
them.
Nevertheless, the impact of these activities is limited. Participation is not available to
municipal operators who are not AGA members and often lack the staff resources necessary
to become involved in this kind of outside activity. Also, not all AGA members participate in
these activities.
Monitoring the Effectiveness of Actions
It is important that the effectiveness of whatever actions are taken to improve distribution
pipeline safety be monitored. The ultimate measure of distribution pipeline system safety is
the number of deaths and injuries and the amount of property damage caused by incidents on
distribution pipeline systems. Fortunately, however, incidents occur relatively infrequently.
Other interim measures are needed to evaluate the effectiveness of any new integrity
management requirements implemented for distribution pipeline systems. An interim
measure might be how any new regulatory initiatives impact system operators (e.g., the
number of assessments or repairs that have been conducted is an interim measure of the
effectiveness of the hazardous liquid and gas transmission integrity management rules). The
program described in this report includes development of a way to measure these impacts and
to develop a baseline from which improvements can be measured.

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A Report to the Congress: Assuring the Integrity of Gas Distribution Pipeline Systems
12
4. Evaluation of Applicability of Transmission IM Program and Practices
OPS promulgated regulations in recent years requiring that pipeline operators (other than
distribution pipeline operators) implement integrity management programs. These regulations
apply to operators of hazardous liquid pipelines (49 CFR 195.452, published at 65 FR 75378
and 67 FR 2136) and to operators of gas transmission pipelines (49 CFR 192, Subpart O,
published at 68 FR 69778). It is reasonable to ask why the same techniques used in these
regulations cannot simply be applied to gas distribution pipeline systems. Both regulations
set requirements for making best use of information to set safety priorities and to perform
continuous evaluations.
Integrity Management Elements
The integrity management regulations for hazardous liquid and gas transmission pipelines are
similar. Both require that operators identify segments of their pipeline where an incident
could create high consequences. Both require that operators implem
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