Pipeline Safety: Safety of Gas Transmission Pipelines, 53086-53102 [2011-21753]

Agencies

• Pipeline and Hazardous Materials Safety Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 76, Number 165 (Thursday, August 25, 2011)]
[Proposed Rules]
[Pages 53086-53102]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-21753]


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DEPARTMENT OF TRANSPORTATION

Pipeline and Hazardous Materials Safety Administration

49 CFR Part 192

[Docket No. PHMSA-2011-0023]
RIN 2137-AE72


Pipeline Safety: Safety of Gas Transmission Pipelines

AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), 
Department of Transportation (DOT).

ACTION: Advance notice of proposed rulemaking (ANPRM).

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SUMMARY: PHMSA is considering whether changes are needed to the 
regulations governing the safety of gas transmission pipelines. In 
particular, PHMSA is considering whether integrity management (IM) 
requirements should be changed, including adding more prescriptive 
language in some areas, and whether other issues related to system 
integrity should be addressed by strengthening or expanding non-IM 
requirements. Among the specific issues PHMSA is considering concerning 
IM requirements is whether the definition of a high-consequence area 
(HCA) should be revised, and whether additional restrictions should be 
placed on the use of specific pipeline assessment methods. With respect 
to non-IM requirements, PHMSA is considering whether revised 
requirements are needed on new construction or existing pipelines 
concerning mainline valves, including valve spacing and installation of 
remotely operated or automatically operated valves; whether 
requirements for corrosion control of steel pipelines should be 
strengthened; and whether new regulations are needed to govern the 
safety of gathering lines and underground gas storage facilities. 
Additional issues PHMSA is considering are addressed in the 
SUPPLEMENTARY INFORMATION Section under background.

DATES: Persons interested in submitting written comments on this ANPRM 
must do so by December 2, 2011. PHMSA will consider late filed comments 
as far as practicable.

FOR FURTHER INFORMATION CONTACT: Mike Israni, by telephone at 202-366-
4571, by fax at 202-366-4566, or by mail at U.S. DOT, PHMSA, 1200 New 
Jersey Avenue, SE., PHP-1, Washington, DC 20590-0001.

ADDRESSES: You may submit comments identified by the docket number 
PHMSA-2011-0023 by any of the following methods:
     Web Site: https://www.regulations.gov. Follow the online 
instructions for submitting comments.
     Fax: 1-202-493-2251.
     Mail: Hand Delivery: U.S. DOT Docket Management System, 
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., 
Washington, DC 20590-0001 between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays.
    Instructions: If you submit your comments by mail, submit two 
copies. To receive confirmation that PHMSA received your comments, 
include a self-addressed stamped postcard.

    Note: Comments are posted without changes or edits to https://www.regulations.gov, including any personal information provided. 
There is a privacy statement published on https://www.regulations.gov. A glossary of terms used in this document can 
be found at the following Web site: https://primis.phmsa.dot.gov/comm/.


SUPPLEMENTARY INFORMATION:

I. Background

    Congress has authorized Federal regulation of the transportation of 
gas by pipeline under the Commerce Clause of the U.S. Constitution. The 
authorization is codified in the Pipeline Safety Laws (49 U.S.C. 60101 
et seq.), a series of statutes that are administered by PHMSA. PHMSA 
promulgated comprehensive minimum safety standards for the 
transportation of gas by pipeline under the Pipeline Safety

[[Page 53087]]

Regulations (PSR; 49 CFR parts 190-199).
    Congress established the current framework for regulating natural 
gas pipelines in the Natural Gas Pipeline Safety Act of 1968, Public 
Law 90-481, which has since been recodified at 49 U.S.C. 60101 et seq. 
That law delegated to DOT the authority to develop, prescribe, and 
enforce minimum Federal safety standards for the transportation of gas, 
including natural gas, flammable gas, or toxic or corrosive gas, by 
pipeline. Congress has since enacted additional legislation that is 
currently codified in the Pipeline Safety Laws.
    In 1992, Congress required regulations be issued to define the term 
``gathering line'' and establish safety standards for certain 
``regulated gathering lines.'' In 1996, Congress directed that DOT 
conduct demonstration projects evaluating the application of risk 
management principles to pipeline safety regulations, and mandated that 
regulations be issued for the qualification and testing of certain 
pipeline personnel.
    In 2002, Congress required that DOT issue regulations requiring 
operators of gas transmission pipelines to conduct risk analyses and to 
implement IM programs under which pipeline segments in HCAs would be 
subject to a baseline assessment within ten years and re-assessments at 
least every seven years. PHMSA administers compliance with these 
statutes and has promulgated comprehensive safety standards and 
regulations for the transportation of natural gas by pipeline. That 
includes regulations for the:
     Design and construction of new pipeline systems or those 
that have been relocated, replaced, or otherwise changed (subparts C 
and D of 49 CFR part 192).
     Protection of steel pipelines from the adverse effects of 
internal and external corrosion (subpart I of 49 CFR part 192).
     Pressure tests of new pipelines (subpart J of 49 CFR part 
192).
     Operation and maintenance of pipeline systems, including 
establishing programs for public awareness and damage prevention, and 
managing the operation of pipeline control rooms (subparts L and M of 
49 CFR part 192).
     Qualification of pipeline personnel (subpart N of 49 CFR 
part 192).
     Management of the integrity of pipelines in HCAs (subpart 
O of 49 CFR part 192).
    The IM requirements of subpart O of 49 CFR part 192 apply to areas 
called high consequence areas or HCA's. An integrity management program 
is a documented set of policies, processes, and procedures that are 
implemented to ensure the integrity of a pipeline. In accordance with 
pipeline safety regulations for gas transmission pipelines (subpart O 
of 49CFR part 192) an operator's integrity management program must 
include, at a minimum, the following elements:
    a. An identification of all high consequence areas;
    b. A baseline assessment plan;
    c. An identification of threats to each covered pipeline segment, 
which must include data integration and a risk assessment. An operator 
must use the threat identification and risk assessment to prioritize 
covered segments for assessment and to evaluate the merits of 
additional preventive and mitigative measures for each covered segment;
    d. A direct assessment plan, if applicable;
    e. Provisions for remediating conditions found during an integrity 
assessment;
    f. A process for continual evaluation and assessment;
    g. If applicable, a plan for confirmatory direct assessment meeting 
the requirement;
    h. Provisions for adding preventive and mitigative measures to 
protect the high consequence area;
    i. A performance plan that includes performance measures;
    j. Record keeping provisions;
    k. A management of change process;
    l. A quality assurance process;
    m. A communication plan that includes procedures for addressing 
safety concerns raised by PHMSA or a State or local pipeline safety 
authority;
    n. Procedures for providing (when requested) a copy of the 
operator's risk analysis or integrity management program to PHMSA or a 
State or local pipeline safety authority; and
    o. Procedures for ensuring that each integrity assessment is being 
conducted in a manner that minimizes environmental and safety risks;
    p. A process for identification and assessment of newly-identified 
high consequence areas.
    A high consequence area is a location that is specially defined in 
the pipeline safety regulations as an area where pipeline releases 
could have greater consequences to health and safety or the 
environment. Regulations require a pipeline operator to take specific 
steps to ensure the integrity of a pipeline for which a release could 
affect an HCA and, thereby, the protection of the HCA. The PSR provide 
gas transmission pipeline operators with two options by which to 
identify which segments of their pipelines are in HCAs: (1) Reliance on 
class locations that historically have been part of the pipeline safety 
regulations for identifying pipelines in more-populated areas, or (2) 
determining segments for which a specified number of structures 
intended for human occupation or a so-called identified site 
(representing areas where people congregate) are located within the 
potential impact radius of a hypothetical pipeline rupture and 
subsequent explosion.
    Other recent rulemaking have addressed different but related issues 
relative to pipeline safety. On October 18, 2010 (75 FR 63774) PHMSA 
published an ANPRM titled ``Pipeline Safety: Safety of On-Shore 
Hazardous Liquid Pipelines.'' In that rulemaking, PHMSA is considering 
whether changes are needed to the regulations covering hazardous liquid 
onshore pipelines. In particular, PHMSA sought comment on whether it 
should extend regulation to certain pipelines currently exempt from 
regulation; whether other areas along a pipeline should either be 
identified for extra protection or be included as additional HCAs for 
IM protection; whether to establish and/or adopt standards and 
procedures for minimum leak detection requirements for all pipelines; 
whether to require the installation of emergency flow restricting 
devices (EFRDs) in certain areas; whether revised valve spacing 
requirements are needed on new construction or existing pipelines; 
whether repair timeframes should be specified for pipeline segments in 
areas outside the HCAs that are assessed as part of the IM; and whether 
to establish and/or adopt standards and procedures for improving the 
methods of preventing, detecting, assessing and remediating stress 
corrosion cracking (SCC) in hazardous liquid pipeline systems.
    On December 4, 2009, PHMSA issued the Distribution Integrity 
Management Final Rule, which extends the pipeline integrity management 
principles that were established for hazardous liquid and natural gas 
transmission pipelines, to the local natural gas distribution pipeline 
systems. This regulation, which became effective in August of 2011, 
requires operators of local gas distribution pipelines to evaluate the 
risks on their pipeline systems, to determine their fitness for 
service, and to take action to address those risks. For older gas 
distribution systems, the appropriate mitigation measures could involve 
major pipe rehabilitation, repair, and replacement programs. At a 
minimum, these measures are needed to requalify those systems as being 
fit for service.

[[Page 53088]]

II. Advance Notice of Proposed Rulemaking

    PHMSA believes that the IM requirements applicable to gas 
transmission pipelines contained in the Pipeline Safety Regulations (49 
CFR parts 190-199) have increased the level of safety associated with 
the transportation of gas in HCA's. Still, incidents with significant 
consequences continue to occur on gas transmission pipelines (e.g., 
incident in San Bruno, CA September 9, 2010). PHMSA has also identified 
concerns during inspections of gas transmission pipeline operator IM 
programs that indicate a potential need to clarify and enhance some 
requirements. PHMSA is now considering whether additional safety 
measures are necessary to increase the level of safety for those 
pipelines that are in non-HCA areas as well as whether the current IM 
requirements need to be revised and enhanced to assure that they 
continue to provide an adequate level of safety in HCAs.
    Within this ANPRM, PHMSA is seeking public comment on 14 specific 
topic areas in two broad categories.
    1. Should IM requirements be revised and strengthened to bring more 
pipeline mileage under IM requirements and to better assure safety of 
pipeline segments in HCAs? Specific topics include:
     Modifying the definition of an HCA.
     Strengthening the Integrity Management requirements in 
part 192.
     Modifying repair criteria.
     Revising the requirements for collecting, validating, and 
integrating pipeline data.
     Making requirements related to the nature and application 
of risk models more prescriptive.
     Strengthening requirements for applying knowledge gained 
through the IM program.
     Strengthening requirements on the selection and use of 
assessment methods, including prescribing assessment methods for 
certain threats (such as manufacturing and construction defects, SCC, 
etc.) or in certain situations such as when certain knowledge is not 
available or data is missing.
    2. Should non-IM requirements be strengthened or expanded to 
address other issues associated with pipeline system integrity? 
Specific topics include:
     Valve spacing and the need for remotely- or automatically-
controlled valves.
     Corrosion control.
     Pipe with longitudinal weld seams with systemic integrity 
issues.
     Establishing requirements applicable to underground gas 
storage.
     Management of Change.
     Quality Management Systems (QMS).
     Exemptions applicable to \1\ facilities installed prior to 
the regulations.
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    \1\ As described below, these exemptions relate to allowable 
maximum operating pressure for pipelines that were in service before 
the initial gas pipeline safety regulations were published. These 
pipelines are commonly known as ``grandfathered'' pipelines.
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     Gathering lines.
    Each topic is discussed in more detail in this document.

A. Modifying the Definition of HCA

    Part 192 has historically included requirements delineating 
pipeline segments by class location based on the population density 
near the pipeline. Class locations are based on the number of buildings 
intended for human occupancy that exist within a ``class location 
unit,'' defined as an area extending 220 yards (100 meters) on either 
side of the centerline of any continuous one-mile (1.6 kilometers) 
length of pipeline. Class locations are defined in Sec.  192.5 as:
     Class 1--10 or fewer buildings intended for human 
occupancy within a class location unit.
     Class 2--more than ten but less than 46 buildings intended 
for human occupancy.
     Class 3--46 or more buildings intended for human 
occupancy.
     Class 4--any class location unit where buildings with four 
or more stories are prevalent.
    Part 192 provides additional protection for higher class location 
areas, principally through provisions that require pipe in these higher 
class locations to operate at lower stress levels.
    With the advent of IM requirements, PHMSA introduced a new 
mechanism in part 192 to define pipeline segments to which additional 
requirements should apply based on the population at risk in the 
vicinity of the pipeline. HCAs are defined in Sec.  192.903 using 
either of two methods. Operators are allowed to pick the method they 
use to identify their HCAs.
    Method 1 builds on the traditional concept of class locations. 
Under this method, all pipeline segments in Class 3 and 4 locations are 
within an HCA. In addition, pipeline segments in Class 1 and 2 
locations are within an HCA if an ``identified site'' is located within 
the ``potential impact circle.'' Identified sites are defined as areas 
in which 20 or more persons congregate for a specified number of days 
each year or facilities occupied by persons who are confined, of 
impaired mobility, or would be difficult to evacuate.
    Method 2 defines HCAs based solely on potential impact circles. A 
potential impact circle is an estimated zone in which the failure of a 
pipeline could have significant impact on people or property. The 
radius of the potential impact circle is calculated using a formula 
specified in the regulations that is based on the diameter and 
operating pressure of the pipeline. A pipeline segment is identified as 
an HCA if the potential impact circle includes 20 or more buildings 
intended for human occupancy or an identified site, regardless of class 
location.
    Some gas transmission pipeline operators do not collect data 
concerning the number of buildings within class location units along 
their pipeline, but rather design all of their pipelines as though they 
were in a Class 3 or 4 location. This approach is often used by 
operators of gas distribution companies that also operate small amounts 
of pipeline meeting part 192's definition as transmission pipeline. 
Method 1 was included in the definition of an HCA in deference to these 
operators, allowing them to avoid the additional costs associated with 
collecting data on nearby buildings that they have not previously 
collected. Method 2 was presumed to identify pipeline segments where 
incidents could produce high consequences more accurately and is 
typically used by pipeline operators who have collected data on local 
structures to determine class locations.
    PHMSA regulates approximately 297,000 miles of onshore gas 
transmission pipelines. Of these, approximately 30,300 miles (10.2%) 
are in Class 2 locations, approximately 33,500 miles (11.3%) are in 
Class 3 locations, and approximately 1600 miles (0.54%) are in Class 4 
locations. Operators have identified approximately 19,000 miles (6.4%) 
of gas transmission pipeline to be within an HCA.
    IM requirements in subpart O of part 192 specify how pipeline 
operators must identify, prioritize, assess, evaluate, repair and 
validate; through comprehensive analyses, the integrity of gas 
transmission pipelines in HCAs. Although operators may voluntarily 
apply IM practices to pipeline segments that are not in HCAs, the 
regulations do not require operators to do so.
    A gas transmission pipeline ruptured in San Bruno, California on 
September 9, 2010, resulting in eight deaths and considerable property 
damage. As a result of this event, public concern has been raised 
regarding whether safety requirements applicable to pipe in populated 
areas can be improved. PHMSA is thus considering expanding the 
definition of an HCA so that more

[[Page 53089]]

miles of pipe are subject to IM requirements.
Questions
    A.1. Should PHMSA revise the existing criteria for identifying HCAs 
to expand the miles of pipeline included in HCAs? If so, what 
amendments to the criteria should PHMSA consider (e.g., increasing the 
number of buildings intended for human occupancy in Method 2?) Have 
improvements in assessment technology during the past few years led to 
changes in the cost of assessing pipelines? Given that most non-HCA 
mileage is already subjected to in-line inspection (ILI) does the 
contemplated expansion of HCAs represent any additional cost for 
conducting integrity assessments? If so, what are those costs? How 
would amendments to the current criteria impact state and local 
governments and other entities?
    A.2. Should the HCA definition be revised so that all Class 3 and 4 
locations are subject to the IM requirements? What has experience shown 
concerning the HCA mileage identified through present methods (e.g., 
number of HCA miles relative to system mileage or mileage in Class 3 
and 4 locations)? Should the width used for determining class location 
for pipelines over 24 inches in diameter that operate above 1000 psig 
be increased? How many miles of HCA covered segments are Class 1, 2, 3, 
and 4? How many miles of Class 2, 3, and 4 pipe do operators have that 
are not within HCAs?
    A.3. Of the 19,004 miles of pipe that are identified as being 
within an HCA, how many miles are in Class 1 or 2 locations?
    A.4. Do existing criteria capture any HCAs that, based on risk, do 
not provide a substantial benefit for inclusion as an HCA? If so, what 
are those criteria? Should PHMSA amend the existing criteria in any way 
which could better focus the identification of an HCA based on risk 
while minimizing costs? If so, how? Would it be more beneficial to 
include more miles of pipeline under existing HCA IM procedures, or, to 
focus more intense safety measures on the highest risk, highest 
consequence areas or something else? If so, why?
    A.5. In determining whether areas surrounding pipeline right-of-
ways meet the HCA criteria as set forth in part 192, is the potential 
impact radius sufficient to protect the public in the event of a gas 
pipeline leak or rupture? Are there ways that PHMSA can improve the 
process of right-of-ways HCA criteria determinations?
    A.6. Some pipelines are located in right-of-ways also used, or 
paralleling those, for electric transmission lines serving sizable 
communities. Should HCA criteria be revised to capture such critical 
infrastructure that is potentially at risk from a pipeline incident?
    A.7. What, if any, input and/or oversight should the general public 
and/or local communities provide in the identification of HCAs? If 
commenters believe that the public or local communities should provide 
input and/or oversight, how should PHMSA gather information and 
interface with these entities? If commenters believe that the public or 
local communities should provide input and/or oversight, what type of 
information should be provided and should it be voluntary to do so? If 
commenters believe that the public or local communities should provide 
input, what would be the burden entailed in providing provide this 
information? Should state and local governments should be involved in 
the HCA identification and oversight process? If commenters believe 
that state and local governments be involved in the HCA identification 
and oversight process what would the nature of this involvement be?
    A.8. Should PHMSA develop additional safety measures, including 
those similar to IM, for areas outside of HCAs? If so, what would they 
be? If so, what should the assessment schedule for non-HCAs be?
    A.9. Should operators be required to submit to PHMSA geospatial 
information related to the identification of HCAs?
    A10. Why has the number of HCA miles declined over the years?
    A.11. If commenters suggest modification to the existing regulatory 
requirements, PHMSA requests that commenters be as specific as 
possible. In addition, PHMSA requests commenters to provide information 
and supporting data related to:
     The potential costs of modifying the existing regulatory 
requirements pursuant to the commenter's suggestions.
     The potential quantifiable safety and societal benefits of 
modifying the existing regulatory requirements.
     The potential impacts on small businesses of modifying the 
existing regulatory requirements.
     The potential environmental impacts of modifying the 
existing regulatory requirements.

B. Strengthening Requirements To Implement Preventive and Mitigative 
Measures for Pipeline Segments in HCAs

    Section 192.935 requires gas transmission pipeline operators to 
take additional measures, beyond those already required by part 192, to 
prevent a pipeline failure and to mitigate the consequences of a 
potential failure in an HCA. The additional measures to be taken are 
not specified. Rather, operators are required to base selection and 
implementation of these measures on the threats the operator has 
identified to each pipeline segment. Operators must use their 
comprehensive risk analyses to identify additional measures appropriate 
to the HCA. However, the rule establishes no objective criteria by 
which decisions concerning additional measures must be made, nor does 
it establish a standard by which such evaluations are to be performed. 
PHMSA is considering revising the IM requirement to add new 
requirements governing selection of additional preventive and 
mitigative measures.
    The current regulations state that these additional measures might 
include: Installing Automatic Shut-off Valves or Remote Control Valves; 
Installing computerized monitoring and leak detection systems; 
replacing pipe segments with pipe of heavier wall thickness; providing 
additional training to personnel on response procedures; conducting 
drills with local emergency responders; and implementing additional 
inspection and maintenance programs, but does not require 
implementation of any of these measures. Operators are also required to 
enhance their damage prevention programs and to take additional 
measures to protect HCA segments subject to the threat of outside force 
damage (non-excavation). Operators are required to install automatic or 
remotely-operable valves if their risk analysis concludes these would 
be an efficient means of adding protection to the HCA in the event of a 
gas release.
    The requirements of Sec.  192.935 apply only to pipeline segments 
in HCAs. As discussed above, only 6.4 percent of gas transmission 
pipeline mileage is currently classified as ``located within HCAs.'' 
Revising the criteria for identifying HCAs could, of course, increase 
the number of pipeline miles to which the requirements of Sec.  192.935 
apply. Still, PHMSA is considering whether these requirements, or other 
requirements for additional preventive and mitigative measures, should 
apply to pipelines outside of HCAs.

[[Page 53090]]

Questions
    B.1. What practices do gas transmission pipeline operators now use 
to make decisions as to whether/which additional preventive and 
mitigative measures are to be implemented? Are these decisions guided 
by any industry or consensus standards? If so, what are those industry 
or consensus standards?
    B.2. Have any additional preventive and mitigative measures been 
voluntarily implemented in response to the requirements of Sec.  
192.935? How prevalent are they? Do pipeline operators typically 
implement specific measures across all HCAs in their pipeline system, 
or do they target measures at individual HCAs? How many miles of HCA 
are afforded additional protection by each of the measures that have 
been implemented? To what extent do pipeline operators implement 
selected measures to protect additional pipeline mileage not in HCAs?
    B.3. Are any additional prescriptive requirements needed to improve 
selection and implementation decisions? If so, what are they and why?
    B.4. What measures, if any, should operators be required explicitly 
to implement? Should they apply to all HCAs, or is there some 
reasonable basis for tailoring explicit mandates to particular HCAs? 
Should additional preventative and mitigative measures include any or 
all of the following: Additional line markers (line-of-sight); depth of 
cover surveys; close interval surveys for cathodic protection (CP) 
verification; coating surveys and recoating to help maintain CP current 
to pipe; additional right-of-way patrols; shorter ILI run intervals; 
additional gas quality monitoring, sampling, and in-line inspection 
tool runs; and improved standards for marking pipelines for operator 
construction and maintenance and one-calls? If so, why?
    B.5. Should requirements for additional preventive and mitigative 
measures be established for pipeline segments not in HCAs? Should these 
requirements be the same as those for HCAs or should they be different? 
Should they apply to all pipeline segments not in HCAs or only to some? 
If not all, how should the pipeline segments to which new requirements 
apply be delineated?
    B.6. If commenters suggest modification to the existing regulatory 
requirements, PHMSA requests that commenters be as specific as 
possible. In addition, PHMSA requests commenters to provide information 
and supporting data related to:
     The potential costs of modifying the existing regulatory 
requirements pursuant to the commenter's suggestions.
     The potential quantifiable safety and societal benefits of 
modifying the existing regulatory requirements.
     The potential impacts on small businesses of modifying the 
existing regulatory requirements.
     The potential environmental impacts of modifying the 
existing regulatory requirements.

C. Modifying Repair Criteria

    The existing IM regulations establish criteria for the timely 
repair of injurious anomalies and defects discovered in the pipe (Sec.  
192.933). These criteria apply to pipeline segments in an HCA, but not 
to segments outside an HCA. PHMSA is considering whether changes are 
needed to the IM rule related to the repair criteria to provide greater 
assurance that injurious anomalies and defects are repaired before the 
defect can grow to a size that leads to a leak or rupture. In addition, 
PHMSA is considering whether or not to establish repair criteria for 
pipeline segments located in areas outside an HCA, to provide greater 
assurance that defects on non-HCA pipeline segments are repaired in a 
timely manner.
    In 2000 and 2002, PHMSA published final rules (65 FR 75378; 12/1/
2000 and 67 FR 2136; 1/16/2002) requiring IM Programs for hazardous 
liquid pipeline operators. In 2003, similar IM regulations were enacted 
for gas pipelines (68 FR 69778; 12/15/2003). Some 43.9% of the nation's 
hazardous liquid pipelines (77,421 miles) and 6.5% of the natural gas 
transmission pipelines (19,004 miles) can potentially affect HCAs and 
thus receive the enhanced level of integrity assessment mandated by the 
IM rule. As a result of assessments, over the six-year period between 
2004 and 2009, hazardous liquid operators have made 6,419 repairs of 
anomalies in HCAs that required immediate attention and remediated 
25,027 other conditions on a scheduled basis. Between 2004 and 2009, 
gas pipeline operators have repaired 1,052 anomalies that required 
immediate attention and 2,239 other conditions. During this six-year 
period, hazardous liquid pipelines repair rate was 41.3 repairs per 100 
HCA miles and gas transmission pipelines repair rate was 17.3 repairs 
per 100 HCA miles.
    The gas IM regulations (Sec.  192.933) require ``prompt action'' to 
address all anomalous conditions discovered. More specifically, the IM 
regulation mandates ``immediate'' pressure reduction, pipeline 
shutdown, or repair of the following conditions: A predicted failure 
pressure less than or equal to 1.1 times (<= 1.1) the established 
maximum allowable operating pressure (MAOP) at the location of the 
anomaly; a dent that has any indication of metal loss, cracking, or a 
stress riser; or any anomaly that in the judgment of the person 
designated by the operator to evaluate assessment results requires 
immediate action. Furthermore, operators must repair within one year, 
smooth dents at the top of the pipeline with a depth greater than six 
percent of the pipeline diameter and dents with a depth greater than 
two percent of the pipeline diameter that affect pipe curvature at a 
girth weld or at a longitudinal seam weld.
    The method used to calculate the predicted failure pressure is 
prescribed in part 192. However, the methods do not account for such 
factors as inaccurate ILI tool results, low tensile steel strength due 
to steel property variances, external loads such as caused by soil 
movement or settlement, or vehicle or farm equipment crossing the 
pipeline at grade. The IM repair criterion (predicted failure pressures 
<= 1.1 MAOP) includes a 10% margin between the predicted failure 
pressure and MAOP. PHMSA is considering if this is adequate to account 
for the above factors as well as operational factors that allow for the 
pipeline to operate up to 110% MAOP for brief periods during upset 
conditions (Sec. Sec.  192.201 and 192.739).
    In addition, regulations at Sec. Sec.  192.103, 192.105, 192.107, 
and 192.111 require the usage of class location design factors. The 
design factor is 0.72 for Class 1 locations. The reciprocal (1.39) can 
be used to express a failure pressure ratio for sound pipe in a Class 1 
location. The failure pressure ratio (FPR) of 1.39 indicates a safety 
factor over MAOP of 39 percent. This ratio is higher in other class 
locations (i.e., 1.67 in Class 2, 2.0 in Class 3, and 2.5 in Class 4). 
PHMSA is considering if class location design factors should be 
explicitly factored into repair criteria.
    The assessments operators have been conducting on pipeline segments 
in HCAs have often extended to areas beyond the HCAs. PHMSA believes 
that many repairs have been made outside HCAs as in HCAs due to 
anomalies identified in these extended assessments, but gas 
transmission pipeline operators are not required to report these 
repairs so specific data are not available. Up to now, PHMSA has 
enforced the IM repair criteria as only applying to the anomalous 
conditions discovered in the HCAs. If, through the integrity assessment 
or information

[[Page 53091]]

analysis, the operator discovers anomalous conditions in the areas 
outside the HCA, the pipeline safety regulations require operators to 
use the prompt remediation requirements in Sec.  192.703 rather than 
the IM repair criteria. Though the remediation requirements in Sec.  
192.703 are more conservative than the IM repair criteria, this 
difference is off-set by the establishment of repair time frames, 
increased monitoring of any anomalous conditions, and other safety off-
sets. The safety factor associated with the repair criteria in non-HCA 
is related to the class location design factor. For example, a Class 1 
location has a 39% safety factor (1.67 in Class 2, 2.0 in Class 3 and 
2.5 in Class 4). PHMSA is now considering whether the IM repair time 
frames should also be made to apply to the pipeline segments located 
outside HCAs when anomalous conditions in these areas are discovered 
through the integrity assessment. This would provide greater assurance 
that defects on non-HCA pipeline segments are repaired in a timely 
manner.
Questions
    C.1. Should the immediate repair criterion of FPR <= 1.1 be revised 
to require repair at a higher threshold (i.e., additional safety margin 
to failure)? Should repair safety margins be the same as new 
construction standards? Should class location changes, where the class 
location has changed from Class 1 to 2, 2 to 3, or 3 to 4 without pipe 
replacement have repair criteria that are more stringent than other 
locations? Should there be a metal loss repair criterion that requires 
immediate or a specified time to repair regardless of its location (HCA 
and non-HCA)?
    C.2. Should anomalous conditions in non-HCA pipeline segments 
qualify as repair conditions subject to the IM repair schedules? If so, 
which ones? What projected costs and benefits would result from this 
requirement?
    C.3. Should PHMSA consider a risk tiering--where the conditions in 
the HCA areas would be addressed first, followed by the conditions in 
the non-HCA areas? How should PHMSA evaluate and measure risk in this 
context, and what risk factors should be considered?
    C.4. What should be the repair schedules for anomalous conditions 
discovered in non-HCA pipeline segments through the integrity 
assessment or information analysis? Would a shortened repair schedule 
significantly reduce risk? Should repair schedules for anomalous 
conditions in HCAs be the same as or different from those in non-HCAs?
    C.5. Have ILI tool capability advances resulted in a need to update 
the ``dent with metal loss'' repair criteria?
    C.6. How do operators currently treat assessment tool uncertainties 
when comparing assessment results to repair criteria? Should PHMSA 
adopt explicit voluntary standards to account for the known accuracy of 
in-line inspection tools when comparing in-line inspection tool data 
with the repair criteria? Should PHMSA develop voluntary assessment 
standards or prescribe ILI assessment standards including wall loss 
detection threshold depth detection, probability of detection, and 
sizing accuracy standards that are consistent for all ILI vendors and 
operators? Should PHMSA prescribe methods for validation of ILI tool 
performance such as validation excavations, analysis of as-found versus 
as-predicted defect dimensions? Should PHMSA prescribe appropriate 
assessment methods for pipeline integrity threats?
    C.7. Should PHMSA adopt standards for conducting in-line 
inspections using ``smart pigs,'' the qualification of persons 
interpreting in-line inspection data, the review of ILI results 
including the integration of other data sources in interpreting ILI 
results, and/or the quality and accuracy of in-line inspection tool 
performance, to gain a greater level of assurance that injurious 
pipeline defects are discovered? Should these standards be voluntary or 
adopted as requirements?
    C.8. If commenters suggest modification to the existing regulatory 
requirements, PHMSA requests that commenters be as specific as 
possible. In addition, PHMSA requests commenters to provide information 
and supporting data related to:
     The potential costs of modifying the existing regulatory 
requirements pursuant to the commenter's suggestions.
     The potential quantifiable safety and societal benefits of 
modifying the existing regulatory requirements.
     The potential impacts on small businesses of modifying the 
existing regulatory requirements.
     The potential environmental impacts of modifying the 
existing regulatory requirements.

D. Improving Requirements for Collecting, Validating, and Integrating 
Pipeline Data

    IM regulations require that gas transmission pipeline operators 
gather and integrate existing data and information concerning their 
entire pipeline that could be relevant to pipeline segments in HCAs 
(Sec.  192.917(b)). Operators are then required to use this information 
in a risk assessment of the covered segments at (Sec.  192.917(c)) that 
must subsequently be used to determine whether additional preventive 
and mitigative measures are needed (Sec.  192.935) and to define the 
intervals at which IM reassessments must be performed (Sec.  192.939). 
Operators' risk analyses and the conclusions reached using them can 
only be as good as the information used to perform the analysis.
    Preliminary results from the investigation of the September 9, 
2010, pipeline rupture and explosion in San Bruno, CA, indicate that 
the pipeline operator's records concerning the pipe segments involved 
in the incident were erroneous. The errors affected basic information 
about the pipeline. For example, the records indicated that pipe in the 
area was 30-inch diameter seamless pipe, whereas pipe fragments 
recovered after the incident showed that seamed pipe was present. Thus, 
analyses performed using the information in the operator's records 
before the incident could not have led to accurate conclusions 
concerning risk, whether or not additional preventive and mitigative 
measures were needed, or what the allowable MAOP should be. PHMSA 
issued an Advisory Bulletin (76 FR 1504; January 10, 2011) on this 
issue. PHMSA is considering whether more prescriptive requirements for 
collecting, validating, integrating and reporting pipeline data is 
necessary.
Questions
    D.1. What practices are now used to acquire, integrate and validate 
data (e.g., review of mill inspection reports, hydrostatic tests 
reports, pipe leaks and rupture reports) concerning pipelines? Are 
practices in place, such as excavations of the pipeline, to validate 
data?
    D.2. Do operators typically collect data when the pipeline is 
exposed for maintenance or other reasons to validate information in 
their records? If discrepancies are found, are investigations conducted 
to determine the extent of record errors? Should these actions be 
required, especially for HCA segments?
    D.3. Do operators try to verify data on pipe, pipe seam type, pipe 
mechanical and chemical properties, mill inspection reports, 
hydrostatic tests reports, coating type and condition, pipe leaks and 
ruptures, and operations and maintenance (O&M) records on a periodic 
basis? Are practices in place to validate data, such as excavation and 
in situ examinations of the pipeline? If so, what are these practices?

[[Page 53092]]

    D.4. Should PHMSA make current requirements more prescriptive so 
operators will strengthen their collection and validation practices 
necessary to implement significantly improved data integration and risk 
assessment practices?
    D.5. If commenters suggest modification to the existing regulatory 
requirements, PHMSA requests that commenters be as specific as 
possible. In addition, PHMSA requests commenters to provide information 
and supporting data related to:
     The potential costs of modifying the existing regulatory 
requirements pursuant to the commenter's suggestions.
     The potential quantifiable safety and societal benefits of 
modifying the existing regulatory requirements.
     The potential impacts on small businesses of modifying the 
existing regulatory requirements.
     The potential environmental impacts of modifying the 
existing regulatory requirements.

E. Making Requirements Related to the Nature and Application of Risk 
Models More Prescriptive

    As described above, current regulations require that gas 
transmission pipeline operators perform risk analyses of their covered 
segments and use these analyses to make certain decisions concerning 
actions to assure the integrity of their pipeline and to enhance 
protection against the consequences of potential incidents. The 
regulations do not prescribe the type of risk analysis nor impose any 
requirements regarding its breadth and scope.
    PHMSA's experience in inspecting operator compliance with IM 
requirements has identified that most pipeline operators use a relative 
index-model approach to performing their risk assessments and that 
there is a wide range in scope and quality of the resulting analyses. 
It is not clear that all of the observed risk analyses can support 
robust decision making and management of the pipeline risk. PHMSA is 
considering making requirements related to the nature and application 
of risk models more prescriptive to improve the usefulness of these 
analyses in informing decisions to control risks from pipelines.
Questions
    E.1. Should PHMSA either strengthen requirements on the functions 
risk models must perform or mandate use of a particular risk model for 
pipeline risk analyses? If so, how and which model?
    E.2. It is PHMSA's understanding that existing risk models used by 
pipeline operators generally evaluate the relative risk of different 
segments of the operator's pipeline. PHMSA is seeking comment on 
whether or not that is an accurate understanding. Are relative index 
models sufficiently robust to support the decisions now required by the 
regulation (e.g., evaluation of candidate preventive and mitigative 
measures, and evaluation of interacting threats)?
    E.3. How, if at all, are existing models used to inform executive 
management of existing risks?
    E.4. Can existing risk models be used to understand major 
contributors to segment risk and support decisions regarding how to 
manage these contributors? If so, how?
    E.5. How can risk models currently used by pipeline operators be 
improved to assure usefulness for these purposes?
    E.6. If commenters suggest modification to the existing regulatory 
requirements, PHMSA requests that commenters be as specific as 
possible. In addition, PHMSA requests commenters to provide information 
and supporting data related to:
     The potential costs of modifying the existing regulatory 
requirements pursuant to the commenters' suggestions.
     The potential quantifiable safety and societal benefits of 
modifying the existing regulatory requirements.
     The potential impacts on small businesses of modifying the 
existing regulatory requirements.
     The potential environmental impacts of modifying the 
existing regulatory requirements.

F. Strengthening Requirements for Applying Knowledge Gained Through the 
IM Program

    IM assessments provide information about the condition of the 
pipeline segments assessed. Identified anomalies that exceed criteria 
in Sec.  192.933 must be remediated immediately (Sec.  192.933(d)(1)) 
or within one year (Sec.  192.933(d)(2)) or must be monitored on future 
assessments (Sec.  192.933(d)(3)). Operators are also expected to apply 
knowledge gained through these assessments to assure the integrity of 
their entire pipeline.
    Section 192.917(e)(5) explicitly requires that operators must 
consider other portions of their pipeline if an assessment identifies 
corrosion requiring repair under the criteria of Sec.  192.933. The 
operator must ``evaluate and remediate, as necessary, all pipeline 
segments (both covered and non-covered) with similar material coating 
and environmental characteristics.''
    Section 192.917 also requires that operators conduct risk 
assessments that follow American Society of Mechanical Engineers/
American National Standards Institute (ASME/ANSI) B31.8S, Section 5, 
and use these analyses to prioritize segments for assessment, and to 
determine what preventive and mitigative measures are needed for 
segments in HCAs. Section 5.4 of ASME/ANSI B31.8S states that ``risk 
assessment methods should be used in conjunction with knowledgeable, 
experienced personnel * * * that regularly review the data input, 
assumptions, and results of the risk assessments.'' That Section 
further states ``An integral part of the risk assessment process is the 
incorporation of additional data elements or changes to facility data'' 
and requires that operators ``incorporate the risk assessment process 
into existing field reporting, engineering, and facility mapping 
processes'' to facilitate such updates. Neither part 192 nor ASME/ANSI 
B31.8S specifies a periodicity by which pipeline risk analyses must be 
reviewed and updated. This is considered a continuous ongoing process.
    PHMSA is considering strengthening requirements related to 
operators' use of insights gained from implementation of its IM 
program.
Questions
    F.1. What practices do operators use to comply with Sec.  
192.917(e)(5)?
    F.2. How many times has a review of other portions of a pipeline in 
accordance with Sec.  192.917(e)(5) resulted in investigation and/or 
repair of pipeline segments other than the location on which corrosion 
requiring repair was initially identified?
    F.3. Do pipeline operators assure that their risk assessments are 
updated as additional knowledge is gained, including results of IM 
assessments? If so, how? How is data integration used and how often is 
it updated? Is data integration used on alignment maps and layered in 
such a way that technical reviews can identify integrity-related 
problems and threat interactions? How often should aerial photography 
and patrol information be updated for IM assessments? If the commenter 
proposes a time period for updating, what is the basis for this 
recommendation?
    F.4. Should the regulations specify a maximum period in which 
pipeline risk assessments must be reviewed and validated as current and 
accurate? If so, why?

[[Page 53093]]

    F.5. Are there any additional requirements PHMSA should consider to 
assure that knowledge gained through IM programs is appropriately 
applied to improve safety of pipeline systems?
    F.6. What do operators require for data integration to improve the 
safety of pipeline systems in HCAs? What is needed for data integration 
into pipeline knowledge databases? Do operators include a robust 
database that includes: Pipe diameter, wall thickness, grade, and seam 
type; pipe coating; girth weld coating; maximum operating pressure 
(MOP); HCAs; hydrostatic test pressure including any known test 
failures; casings; any in-service ruptures or leaks; ILI surveys 
including high resolution--magnetic flux leakage (HR-MFL), HR-geometry/
caliper tools; close interval surveys; depth of cover surveys; 
rectifier readings; test point survey readings; alternating current/
direct current (AC/DC) interference surveys; pipe coating surveys; pipe 
coating and anomaly evaluations from pipe excavations; SCC excavations 
and findings; and pipe exposures from encroachments?
    F.7. If commenters suggest modification to the existing regulatory 
requirements, PHMSA requests that commenters be as specific as 
possible. In addition, PHMSA requests commenters to provide information 
and supporting data related to:
     The potential costs of modifying the existing regulatory 
requirements pursuant to the commenter's suggestions.
     The potential quantifiable safety and societal benefits of 
modifying the existing regulatory requirements.
     The potential impacts on small businesses of modifying the 
existing regulatory requirements.
     The potential environmental impacts of modifying the 
existing regulatory requirements.

G. Strengthening Requirements on the Selection and Use of Assessment 
Methods

    The existing IM regulations require that baseline and periodic 
assessments of pipeline segments in an HCA be performed using one of 
four methods:
    (1) In-line inspection;
    (2) Pressure test per subpart J;
    (3) Direct assessment to address the threats of external and 
internal corrosion and SCC; or
    (4) Other technology that an operator demonstrates can provide an 
equivalent understanding of the condition of line pipe.
    Operators must notify PHMSA in advance if they plan to use ``other 
technology.'' Operators must apply one or more methods, depending on 
the threats to which the covered segment is susceptible.
    The three specified assessment methods provide different levels of 
understanding of pipeline integrity. In-line inspection, using modern 
technology, can provide information concerning small anomalies that can 
be evaluated and addressed, if needed, before they adversely affect 
pipeline integrity. In-line inspection, with appropriate selection of 
tools, is capable of detecting many types of anomalies including 
corrosion, dents and deformation, selective seam corrosion and other 
seam issues, and SCC. Pressure testing provides no information about 
the existence of anomalies that do not result in leaks or failures 
during the pressure test. Pressure tests are conducted at a pressure 
higher than MAOP to afford a safety margin between MAOP and a pressure 
at which failure might occur. Direct assessment can identify conditions 
(e.g., coating holidays, presence of water in the gas stream) that 
could lead to degradation and, through related excavations and direct 
examination, knowledge of whether such degradation is occurring in the 
locations examined. Direct assessment is not a satisfactory assessment 
technology to identify or characterize threats such as material or 
construction defects other than coating holidays, unless it is used 
with other non-destructive exam technologies that conduct a full pipe 
and weld body examination.
    Standards for conducting pressure tests are specified in subpart J 
of part 192 and minimum pressures for these tests can be found at 
Sec. Sec.  192.505, 192.507, 192.619, 192.620. Standards for external 
corrosion direct assessment (ECDA) are specified in Sec.  192.925 and 
in National Association of Corrosion Engineers (NACE) NACE RP0502-2008 
(incorporated by reference). Standards for internal corrosion direct 
assessment (ICDA) and SCC direct assessment (SCCDA) are in Sec. Sec.  
192.927 and 192.929 respectively, but in neither case is a consensus 
standard incorporated as is the case for ECDA. Standards for in-line 
inspection are not specified in the regulations.
    PHMSA is considering strengthening the requirements for selection 
and use of assessment methods.
Questions
    G.1. Have any anomalies been identified that require repair through 
various assessment methods (e.g., number of immediate and total repairs 
per mile resulting from ILI assessments, pressure tests, or direct 
assessments)?
    G.2. Should the regulations require assessment using ILI whenever 
possible, since that method appears to provide the most information 
about pipeline conditions? Should restrictions on the use of assessment 
technologies other than ILI be strengthened? If so, in what respect? 
Should PHMSA prescribe or develop voluntary ILI tool types for 
conducting integrity assessments for specific threats such as corrosion 
metal loss, dents and other mechanical damage, longitudinal seam 
quality, SCC, or other attributes?
    G.3. Direct assessment is not a valid method to use where there are 
pipe properties or other essential data gaps. How do operators decide 
whether their knowledge of pipeline characteristics and their 
confidence in that knowledge is adequate to allow the use of direct 
assessment?
    G.4. How many miles of gas transmission pipeline have been modified 
to accommodate ILI inspection tools? Should PHMSA consider additional 
requirements to expand such modifications? If so, how should these 
requirements be structured?
    G.5. What standards are used to conduct ILI assessments? Should 
these standards be incorporated by reference into the regulations? 
Should they be voluntary?
    G.6. What standards are used to conduct ICDA and SCCDA assessments? 
Should these standards be incorporated into the regulations? If the 
commenter believes they should be incorporated into the regulations, 
why? What, if any, remediation, hydrostatic test or replacement 
standards should be incorporated into the regulations to address 
internal corrosion and SCC?
    G.7. Does NACE SP0204-2008 (formerly RP0204), ``Stress Corrosion 
Cracking Direct Assessment Methodology'' address the full lifecycle 
concerns associated with SCC?
    G.8. Are there statistics available on the extent to which the 
application of NACE SP0204-2008, or other standards, have affected the 
number of SCC indications operators have detected and remediated on 
their pipelines?
    G.9. Should a one-time pressure test be required to address 
manufacturing and construction defects?
    G.10. Have operators conducted quality audits of direct assessments 
to determine the effectiveness of direct assessment in identifying 
pipeline defects?
    G.11. If commenters suggest modification to the existing regulatory 
requirements, PHMSA requests that commenters be as specific as 
possible. In addition, PHMSA requests

[[Page 53094]]

commenters to provide information and supporting data related to:
     The potential costs of modifying the existing regulatory 
requirements pursuant to the commenter's suggestions.
     The potential quantifiable safety and societal benefits of 
modifying the existing regulatory requirements.
     The potential impacts on small businesses of modifying the 
existing regulatory requirements.
     The potential environmental impacts of modifying the 
existing regulatory requirements.

H. Valve Spacing and the Need for Remotely or Automatically Controlled 
Valves

    Gas transmission pipelines are required to incorporate 
sectionalizing block valves. These valves can be used to isolate a 
section of the pipeline for maintenance or in response to an incident. 
Valves are required to be installed at closer intervals in areas where 
the population density near the pipeline is higher. Section 192.179 
requires that block valves be located such that:

    ``(1) Each point on the pipeline in a Class 4 location must be 
within 2\1/2\ miles (4 kilometers) of a valve.
    (2) Each point on the pipeline in a Class 3 location must be 
within 4 miles (6.4 kilometers) of a valve.
    (3) Each point on the pipeline in a Class 2 location must be 
within 7\1/2\ miles (12 kilometers) of a valve.
    (4) Each point on the pipeline in a Class 1 location must be 
within 10 miles (16 kilometers) of a valve.''

    These requirements apply to initial gas transmission pipeline 
construction. If population increases after a pipeline is placed in 
service, such that the class location changes, operators must reduce 
pressure, conduct pressure tests or verify the adequacy of prior 
pressure tests, or replace the pipeline to allow continued operation at 
the existing pressure. If operators replace the pipeline, then Sec.  
192.13(a)(1) would require that the new pipeline be ``designed, 
installed, constructed, initially inspected, and initially tested in 
accordance with this part,'' including the requirements for valve 
spacing. If operators reduce pressure or verify that prior pressure 
tests are sufficient to justify continued operation without reducing 
pressure or replacing the pipeline, then no current regulation would 
require that new valves be installed to comply with the spacing 
requirements in Sec.  192.179.
    Sectionalizing block valves are not required to be remotely 
operable or to operate automatically in the event of an unexpected 
reduction in pressure (e.g., from a pipeline rupture). Congress has 
previously required PHMSA to ``assess the effectiveness of remotely 
controlled valves to shut off the flow of natural gas in the event of a 
rupture'' and to require use of such valves if they were shown 
technically and economically feasible.\2\ The National Transportation 
Safety Board (NTSB) has also issued a number of recommendations 
concerning requirements for use of automatic or remotely operated 
mainline valves, including one following a 1994 pipeline rupture in 
Edison, NJ.\3\ PHMSA's predecessor agency, the Research and Special 
Programs Administration (RSPA) conducted the Congressionally-mandated 
evaluation and concluded that remotely and automatically controlled 
mainline valves are technically feasible but not, on a generic basis, 
economically feasible.\4\ Nevertheless, IM regulations require that an 
operator must install an automatic or remotely operated valve if the 
operator determines, based on a risk analysis, that these would be an 
efficient means of adding protection to a HCA in the event of a gas 
release (Sec.  192.935(c)). In publishing this regulation, PHMSA 
acknowledged its prior conclusion that installation of these valves was 
not economically feasible but noted that this was a generic conclusion. 
PHMSA stated that it did not expect operators to re-perform the generic 
analyses but rather to ``evaluate whether the generic conclusions are 
applicable to their HCA pipeline segments.'' \5\
---------------------------------------------------------------------------

    \2\ Accountable Pipeline Safety and Partnership Act of 1996, 
Public Law 104-304.
    \3\ NTSB, ``Texas Eastern Transmission Corporation Natural Gas 
Pipeline Explosion and Fire, Edison, New Jersey, March 23, 1994,'' 
PB95-916501, NTSB/PAR-95/01, January 18, 1995.
    \4\ DOT, RSPA, ``Remotely Controlled Valves on Interstate 
Natural Gas Pipelines, (Feasibility Determination Mandated by the 
Accountable Pipeline Safety and Partnership Act of 1996), September 
1999.
    \5\ Federal Register, December 15, 2003, 68 FR 69798, column 3.
---------------------------------------------------------------------------

    The incident in San Bruno, CA on September 9, 2010, has raised 
public concern about the ability of pipeline operators to isolate 
sections of gas transmission pipelines in the event of an accident 
promptly and whether remotely or automatically operated valves should 
be required to assure this. PHMSA is considering changes to its 
requirements for sectionalizing block valves in response to these 
concerns.
Questions
    H.1. Are the spacing requirements for sectionalizing block valves 
in Sec.  192.179 adequate? If not, why not and what should be the 
maximum or minimum separation distance? When class locations change as 
a result of population increases, should additional block valves be 
required to meet the new class location requirements? Should a more 
stringent minimum spacing of either remotely or automatically 
controlled valves be required between compressor stations? Under what 
conditions should block valves be remotely or automatically controlled? 
Should there be a limit on the maximum time required for an operator's 
maintenance crews to reach a block valve site if it is not a remotely 
or automatically controlled valve? What projected costs and benefits 
would result from a requirement for increased placement of block 
valves?
    H.2. Should factors other than class location be considered in 
specifying required valve spacing?
    H.3. Should the regulations be revised to require explicitly that 
new valves must be installed in the event of a class location change to 
meet the spacing requirements of Sec.  192.179? What would be the costs 
and benefits associated with such a change?
    H.4. Should the regulations require addition of valves to existing 
pipelines under conditions other than a change in class location?
    H.5. What percentage of current sectionalizing block valves are 
remotely operable? What percentage operate automatically in the event 
of a significant pressure reduction?
    H.6. Should PHMSA consider a requirement for all sectionalizing 
block valves to be capable of being controlled remotely?
    H.7. Should PHMSA strengthen existing requirements by adding 
prescriptive decision criteria for operator evaluation of additional 
valves, remote closure, and/or valve automation? Should PHMSA set 
specific guidelines for valve locations in or around HCAs? If so, what 
should they be?
    H.8. If commenters suggest modification to the existing regulatory 
requirements, PHMSA requests that commenters be as specific as 
possible. In addition, PHMSA requests commenters to provide information 
and supporting data related to:
     The potential costs of modifying the existing regulatory 
requirements pursuant to the commenter's suggestions.
     The potential quantifiable safety and societal benefits of 
modifying the existing regulatory requirements.
     The potential impacts on small businesses of modifying the 
existing regulatory requirements.

[[Page 53095]]

     The potential environmental impacts of modifying the 
existing regulatory requirements.

I. Corrosion Control

    Gas transmission pipelines are generally constructed of steel pipe, 
and corrosion is a threat of potential concern. Requirements for 
corrosion control of gas transmission pipelines are in subpart I of 
part 192. This subpart includes requirements related to external 
corrosion, internal corrosion, and atmospheric corrosion. However, this 
subpart does not include requirements for the specific threat of SCC.
    Buried pipelines installed after July 31, 1971, are required to 
have a protective coating and CP unless the operator can demonstrate 
that the pipeline is not in a corrosive environment. Buried pipelines 
installed before that date must have CP if they have an effective 
coating or, if bare or with ineffective coating, if active corrosion is 
found to exist. Appendix D of part 192 provides standards for the 
adequacy of CP and operators are required to conduct tests periodically 
to demonstrate that these standards are met.
    These requirements have proven effective in minimizing the 
occurrence of incidents caused by gas transmission pipeline corrosion. 
Many of the provisions in subpart I, however, are general. They 
provide, for example, that each pipeline under CP ``have sufficient 
test stations or other contact points for electrical measurement to 
determine the adequacy of CP'' (Sec.  192.469) rather than specifying 
the number or spacing of such test stations. Operators are required to 
take ``prompt'' remedial action to address problems with CP (Sec.  
192.465(d)), but ``prompt'' is not defined. In addition, the 
regulations do not now include provisions addressing issues that 
experience has shown can be important to protecting pipelines from 
corrosion damage:
     Surveying post-construction for coating damage, using 
techniques such as direct