81 FR 90062 - Pipeline Safety: High Consequence Area Identification Methods for Gas Transmission Pipelines

DEPARTMENT OF TRANSPORTATION
Pipeline and Hazardous Materials Safety Administration

Federal Register Volume 81, Issue 239 (December 13, 2016)

Page Range		90062-90064
FR Document		2016-29880

PHMSA is issuing this advisory bulletin to remind gas transmission pipeline operators of certain previously issued guidance and provide operators with additional guidance for the identification of High Consequence Areas (HCAs) along pipeline right-of-ways. This advisory bulletin provides suggestions for accurately mapping and integrating HCA data, documenting how mapping systems are used, periodically verifying and updating their mapping systems, utilizing buffer zones (tolerances) to provide additional protection around the calculated potential impact radius (PIR) along their pipelines, and ensuring the accuracy of class locations. The bulletin emphasizes that HCA identification relies on pipeline-specific information regarding the location, size, and operating characteristics of the line, as well as the identification of structures, specified sites, and their intended usage along the pipeline right-of-way.

Federal Register, Volume 81 Issue 239 (Tuesday, December 13, 2016)

[Federal Register Volume 81, Number 239 (Tuesday, December 13, 2016)]
[Notices]
[Pages 90062-90064]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2016-29880]


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DEPARTMENT OF TRANSPORTATION

Pipeline and Hazardous Materials Safety Administration

[Docket No. PHMSA-2016-0065]


Pipeline Safety: High Consequence Area Identification Methods for 
Gas Transmission Pipelines

AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA); 
DOT.

ACTION: Notice; Issuance of Advisory Bulletin.

-----------------------------------------------------------------------

SUMMARY: PHMSA is issuing this advisory bulletin to remind gas 
transmission pipeline operators of certain previously issued guidance 
and provide operators with additional guidance for the identification 
of High Consequence Areas (HCAs) along pipeline right-of-ways. This 
advisory bulletin provides suggestions for accurately mapping and 
integrating HCA data, documenting how mapping systems are used, 
periodically verifying and updating their mapping systems, utilizing 
buffer zones (tolerances) to provide additional protection around the 
calculated potential impact radius (PIR) along their pipelines, and 
ensuring the accuracy of class locations. The bulletin emphasizes that 
HCA identification relies on pipeline-specific information regarding 
the location, size, and operating characteristics of the line, as well 
as the identification of structures, specified sites, and their 
intended usage along the pipeline right-of-way.

FOR FURTHER INFORMATION CONTACT: Allan Beshore by phone at 405-834-8344 
or email at [email protected]. All materials in this docket may be 
accessed electronically at http://www.regulations.gov. Information 
about PHMSA may be found at http://www.phmsa.dot.gov.

SUPPLEMENTARY INFORMATION: 

I. Background

    A key component of PHMSA's pipeline safety regulations is its 
integrity management (IM) program. For gas transmission pipelines, this 
program is outlined in Subpart O of 49 CFR part 192 and is based on the 
concept that pipeline operators need to identify those segments of 
their pipeline systems that pose the greatest risk to human life, 
property, and the environment, and to take extra precautions to ensure 
their safety. These higher-risk areas are known as ``HCAs.'' Each 
operator is required to survey its entire pipeline system to identify 
all pipeline segments

[[Page 90063]]

that could affect HCAs. Since the greatest risk posed by gas 
transmission pipelines is the risk of fire and explosion resulting from 
pipeline leaks and ruptures, gas HCAs consist of highly populated areas 
and ``identified sites'' where people regularly gather or live.
    An operator's first step in developing a robust IM program is to 
properly identify and map all HCAs and perform periodic updates to the 
evaluation process to maintain accurate and current information. 
Subpart O of part 192 allows operators flexibility in making 
determinations to identify HCAs by defining two different 
identification methods, generally referred to as Method 1 or Method 2.
    Both methods require the operator to determine ``identified sites'' 
and calculate a PIR, using a formula to calculate the radius of a 
circle within which the potential failure of a pipeline could have 
significant impact on people or property. While Method 1 includes all 
pipe segments within Class 3 and Class 4 locations\1\ and ``identified 
areas within a PIR in Class 1 and 2 locations,'' Method 2 includes 
``identified sites'' \2\ within a PIR only, regardless of the class 
location, or the combination of ``identified sites'' with 20 or more 
buildings intended for human occupancy.
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    \1\ Under 49 CFR 192.5, all transmission pipelines fall into one 
of four ``class locations.'' Class 1 locations are offshore areas 
and all segments (``class location units'') one mile in length that 
contain 10 or fewer buildings intended for human occupancy Class 2 
locations are units with more than 10, but fewer than 46, such 
buildings. Class 3 locations are units with 46 or more buildings or 
an area where the pipeline lies within 100 yards of either a 
building or a small, well-defined outside area (such as a playground 
or recreation area) that is occupied by 20 or more people on at 
least 5 days a week for 10 weeks in any 12-month period. Class 4 
locations are units where buildings with 4 or more stories are 
prevalent.
    \2\ ``Identified sites'' is a defined term under 49 CFR 192.903 
in PHMSA's IM regulations and refers generally to the type of 
specific areas included under the Class 3 location definition above, 
plus facilities occupied by persons who are confined, are of 
impaired mobility, or would be difficult to evacuate, including 
schools, prisons, nursing homes, etc.
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    A review of PHMSA and state data from ``first-round'' IM 
inspections indicates a large percentage of intrastate and small 
operators have been inconsistent in determining HCAs using ``identified 
sites,'' and operators that initially used Method 1 to identify HCAs 
have since transitioned to Method 2.
    On July 17, 2003, (68 FR 42458) PHMSA published an advisory 
bulletin titled ``Identified Sites as Part of High Consequence Areas 
for Gas Integrity Management Programs'' to provide guidance to gas 
transmission operators on the steps PHMSA expected them to take to 
determine ``identified sites'' along their pipelines. PHMSA intended 
the guidance in the advisory bulletin to support operators in 
identifying these sites for planning their IM programs and determined 
that certain measures, if properly applied, would satisfy the intent of 
the regulation.
    On December 15, 2003, (68 FR 69778) PHMSA published a final rule 
titled: ``Pipeline Integrity Management in High Consequence Areas (Gas 
Transmission Pipelines)'' that provided requirements for the 
identification of HCAs and further explanation of how best to conduct 
the identification process.
    In the preamble of the rule, PHMSA provided the basis for defining 
an identified site as follows:
    Define an identified site as any of the following within a 
Potential Impact Circle:
    1. A facility housing persons of limited mobility that is known to 
public safety officials, emergency response officials, or local 
emergency planning committee, and which meets one of the following 
three criteria: (a) Is visibly marked, (b) is licensed or registered by 
a Federal, state, or local agency, or (c) is listed on a map maintained 
by or available from a Federal, State, or local agency, or
    2. An outdoor area where people congregate that is known to public 
safety officials, emergency response officials or local emergency 
planning committee and which is occupied by 20 or more people on at 
least 50 days per year, or
    3. A building occupied by 20 or more people 5 days per week, 10 
weeks in any 12-month period (the days and weeks need not be 
consecutive).
    To assist operators in meeting the requirements of the regulation, 
PHMSA introduced a ``buffer zone'' concept. This additional safety 
margin was intended to compensate for inaccuracies (e.g., incorrect 
pipeline center data or mapping errors) when implementing the 
regulation and determining the PIR. As defined in Sec.  192.903, a PIR 
is the radius of the potential impact circle (PIC), measured in feet 
surrounding the point of failure, within which the potential failure of 
a pipeline could have significant impact on people or property. Part 
192 provides the formula for determining a PIR that takes into account 
the Maximum Allowable Operating Pressure (MAOP) in the pipeline segment 
in pounds per square inch, the nominal diameter of the pipeline in 
inches, and a numeric factor, which varies for other gases depending 
upon their heat of combustion.\3\
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    \3\ Operators transporting gas other than natural gas must use 
section 3.2 of ASME/ANSI B31.8S (incorporated by reference, see 
Sec.  192.7) to calculate the impact radius formula. For flammable 
gases, additional information on factors may be found in TTO-13, 
Potential Impact Radius Formulae for Flammable Gases Other Than 
Natural Gas Subject to 49 CFR 192, June 2005, Table 7.1 which can be 
found in http://primis.phmsa.dot.gov/gasimp/docs/TTO13_PotentialImpactRadius_FinalReport_June2005.pdf).
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    Following the publication of the regulations and advisory bulletin, 
PHMSA inspections have revealed that operators may need further 
guidance regarding the identification of HCAs, as operators have been 
inconsistent in determining HCAs using ``identified sites.''
    Additionally, in CY 2015, the National Transportation Safety Board 
(NTSB) published SS-15-01, ``Safety Study: Integrity Management of Gas 
Transmission Pipelines in High Consequence Areas.'' The study was 
conducted in response to concerns about deficiencies in operators' IM 
programs that had been identified by the NTSB in three gas transmission 
pipeline accidents from the previous 5 years. Recommendation P-15-06, 
issued as a part of the study, recommended that PHMSA ``[a]ssess the 
limitations associated with the current process for identifying high 
consequence areas, and disseminate the results of [the] assessment to 
the pipeline industry, inspectors, and the public.'' PHMSA has noted 
that proper identification of an HCA and periodic verification relies 
on two key types of information: (1) Pipeline-specific information that 
includes the accurate location of the centerline of the pipeline, the 
nominal diameter of the pipeline, and the pipeline segment's MAOP; and 
(2) all the structures and their usage (including occupancy) located 
along the pipeline. PHMSA subject matter experts performed an 
assessment of the impact of these two issues on identifying HCAs using 
Methods 1 and 2 as defined in Sec.  192.903, by reviewing failure 
investigations, inspector experiences, and Gas IM inspection results 
and has documented these insights in this advisory bulletin. PHMSA will 
be including these insights in updated inspection materials, as 
appropriate.
    PHMSA is publishing this advisory bulletin to meet NTSB 
Recommendation P-15-06 by providing operators with additional guidance 
on how to improve the accuracy of their class location identification 
process, which may also lead to operators improving HCA identification.

[[Page 90064]]

II. Advisory Bulletin (ADB-2016-07)

    To: Owners and Operators of Natural Gas Pipelines.
    Subject: High Consequence Area Identification Methods.
    Advisory: PHMSA is issuing this advisory bulletin to inform owners 
and operators of gas transmission pipelines that PHMSA has developed 
guidance on the identification and periodic verification of HCAs, 
including the application of a buffer zone to the PIR, and information 
regarding the accuracy of class locations. PHMSA is recommending that 
operators review and consistently monitor class location and PIR data 
on an annual basis as part of their IM program. PHMSA anticipates this 
annual review will improve the accuracy of operator HCA determinations.
    A review of early PHMSA inspections has shown that many operators 
(28%) did not have procedures to adequately describe how to identify 
HCAs, using Method 1 or Method 2. To effectively use Method 2, 
operators should have a detailed and documented process in place to 
monitor the conditions surrounding their pipelines, including the 
existence of ``identified sites.'' Therefore, PHMSA is reminding 
operators of the existing guidance for making those determinations and 
is providing additional recommendations on how to improve the accuracy 
of HCA identification. Specifically:
     PHMSA expects that most large operators will use a 
geographic information system or similar mapping software for segment 
identification. Operators should be able to demonstrate the usability 
of their system and show a graphical overlay of HCAs with their 
pipeline system.
     An operator not using geographic information system or 
similar mapping software should describe or demonstrate how it 
performed its HCA segment identifications.
     For both geographic information system-based and non-
geographic information system-based HCA identification processes, the 
operator should address how it will deal with tolerances (or buffers) 
on top of the calculated PIR regarding the accuracy of measured 
distances to structures and the location of the pipeline centerline. 
PHMSA recognizes that global positioning system measurements and maps 
have some limitations in their accuracy; however, the rule applies to 
pipelines--and distances from those pipelines--as they actually exist 
in the field.
    PHMSA also reminds operators of the need to continually improve the 
accuracy of their pipeline data. As technology advances, pipeline 
operators have more access to tools that provide improved accuracy for 
determining class locations (including the determination of the 
centerline of the pipeline), the application of aerial photography, 
pipeline operating characteristics (diameter, grade, MAOP), population 
studies, and mapping software. It is important that operators 
continuously improve the accuracy of the data and conduct the required 
class location studies as required in Sec.  192.609, along with the 
confirmation or revision of MAOP in Sec.  192.611, as this affects the 
operation of their pipelines. Operators should include provisions in 
their continuing surveillance monitoring procedures (Sec.  192.613) to 
constantly monitor the surrounding conditions, report that information, 
and update their maps each calendar year. This is similar to the 
requirements for including newly identified areas for segments in HCAs 
(Sec.  192.905(c)) and for filing annual report information relating to 
the performance of IM plans (Sec.  191.17).
    Operators must use MAOP when calculating PIR, and accurate pipeline 
data is necessary to ensure that operators are correctly applying the 
MAOP value in the PIR calculation when determining whether areas 
qualify as HCAs. PHMSA also recommends that operators review their 
pipeline centerline and map data to account for any potential 
inaccuracies or data limitations and to add an appropriate buffer zone 
to the calculated PIR. This would establish a PIR that includes any 
areas that could potentially be excluded due to data limitations.
    A list of PHMSA-provided frequently asked questions on this subject 
can be found on the gas IM site at: https://primis.phmsa.dot.gov/gasimp/index.htm. Gas IM Frequently Asked Question Number 174 reminds 
operators that they should consider the uncertainties in the distances 
they measure or infer when evaluating PICs and consider geographic 
information system accuracy in locating HCAs:
    ``. . . Operators may use a combination of techniques in order to 
account for these inaccuracies. For instance, aerial photography may be 
used as an initial screen. Field measurements (such as pipeline 
locators along with chainage measurements or survey quality range 
finders) may be used to verify if structures near the edge of the PIC 
(i.e., within the range of mapping/geographic information system 
inaccuracies) are actually inside or outside the PIC. PHMSA will 
inspect each operator's approach to assure that the operator's process 
is adequate to identify all covered segments.''
    PHMSA recommends operators frequently and consistently review their 
data--including class location data--for potential inaccuracies or 
limitations, and add a buffer zone to the calculated PIR to help ensure 
proper HCA identification. The purpose and usage of buildings, open 
structures, and outside areas can shift over time, changing the number 
of ``identified sites'' in a PIR, and therefore, whether an area is an 
HCA. PHMSA believes that if operators review class location and PIR 
data on an annual basis as a part of their IM programs, the accuracy of 
HCA determinations will be greatly improved.

    Issued in Washington, DC, on December 8, 2016, under authority 
delegated in 49 CFR 1.97.
Alan K. Mayberry,
Acting Associate Administrator for Pipeline Safety.
[FR Doc. 2016-29880 Filed 12-12-16; 8:45 am]
 BILLING CODE 4910-60-P

90062 Federal Register / Vol. 81, No. 239 / Tuesday, December 13, 2016 / Notices

SUPPLEMENTARY INFORMATION: proposed to extend the 75 in3 (1.23 L) DEPARTMENT OF TRANSPORTATION
Public Action Requested volume limitation of DOT–39 cylinders
to all liquefied flammable compressed Pipeline and Hazardous Materials
PHMSA advises offerors of DOT–39 gases by revising § 173.304 to delete Safety Administration
cylinders having an internal volume Note 9 from the table at § 173.304(a)(2) [Docket No. PHMSA–2016–0065]
exceeding 75 cubic inches (in3) (1.23 L) and adding §§ 173.304a and 173.304b.1
that such cylinders should not be filled Pipeline Safety: High Consequence
RSPA received several comments in
with liquefied flammable compressed Area Identification Methods for Gas
opposition to extending the limit to all
gas. PHMSA further advises the public Transmission Pipelines
not to use any DOT–39 cylinder with an liquefied flammable compressed gases
internal volume greater than 75 in3 (1.23 which would have been codified in AGENCY: Pipeline and Hazardous
L) containing a liquefied flammable § 173.304a(a)(3). RSPA published a final Materials Safety Administration
compressed gas. rule on August 8, 2002 and, based on (PHMSA); DOT.
the opposing comments, decided not to
Safety Concern ACTION: Notice; Issuance of Advisory
extend the 75 in3 (1.23 L) limitation to
Bulletin.
The release of a liquefied flammable all liquefied flammable compressed
compressed gas from or rupture of such gases in a DOT–39 cylinder at that time. SUMMARY: PHMSA is issuing this
a cylinder having an internal volume However, in the process of publishing advisory bulletin to remind gas
exceeding 75 in3 (1.23 L) is a safety the final rule, the agency inadvertently transmission pipeline operators of
concern that could result in extensive omitted the 75 in3 (1.23 L) limitation for certain previously issued guidance and
property damage, serious personal liquefied flammable compressed gas and provide operators with additional
injury, or even death. A liquefied liquefied petroleum gas.2 guidance for the identification of High
flammable compressed gas has a stored Consequence Areas (HCAs) along
energy that is several times greater than On November 13, 2014, PHMSA
pipeline right-of-ways. This advisory
that of a non-liquefied compressed gas. accepted a petition for rulemaking (P–
bulletin provides suggestions for
Further, a DOT–39 cylinder can have a 1622) from Worthington Cylinders to
accurately mapping and integrating
volume of up to 1,526 in3 (25 L) at a address this error in a rulemaking. On
HCA data, documenting how mapping
service pressure of 500 psig or less and, July 26, 2016, PHMSA published in the systems are used, periodically verifying
as such, can have up to 22 times the Federal Register an NPRM titled, and updating their mapping systems,
stored energy of a DOT–39 cylinder ‘‘Hazardous Materials: Miscellaneous utilizing buffer zones (tolerances) to
limited to 75 in3 (1.23 L). Additionally, Amendments Pertaining to DOT provide additional protection around
because of the design specifications that Specification Cylinders (RRR),’’ [81 FR the calculated potential impact radius
allow for thinner walls when used at 48977; Docket No. PHMSA–2011–0140 (PIR) along their pipelines, and ensuring
lower pressure, the cylinders may be at (HM–234) 3] that again proposes to the accuracy of class locations. The
greater risk from corrosion or puncture. extend the limit on the internal volume bulletin emphasizes that HCA
Given the known risks associated with of DOT–39 cylinders to use with all identification relies on pipeline-specific
cylinders that are filled with liquefied liquefied flammable compressed gases, information regarding the location, size,
flammable compressed gases, PHMSA is thus correcting the inadvertently and operating characteristics of the line,
issuing this safety advisory notice to omitted size limitation and expanding as well as the identification of
inform offerors and users of DOT–39 the applicability to capture those structures, specified sites, and their
cylinders that cylinders with an internal liquefied flammable compressed gases intended usage along the pipeline right-
volume of 75 in3 (1.23 L) or more (e.g., difluoromethane (Refrigerant gas R of-way.
should not be filled with liquefied 32)) either not reflected in the FOR FURTHER INFORMATION CONTACT:
flammable compressed gas. § 173.304a(a)(2) table or not considered Allan Beshore by phone at 405–834–
Background a liquefied petroleum gas. 8344 or email at allan.beshore@dot.gov.
This safety advisory notice is being Issued in Washington, DC on December 5,
All materials in this docket may be
issued in part because of concern over 2016.
accessed electronically at http://
confusion about the regulatory www.regulations.gov. Information about
William S. Schoonover, PHMSA may be found at http://
requirements when using DOT–39 Acting Associate Administrator for
cylinders for liquefied compressed www.phmsa.dot.gov.
Hazardous Materials Safety, Pipeline and
gases. Historically, the Hazardous Hazardous Materials Safety Administration. SUPPLEMENTARY INFORMATION:
Materials Regulations (HMR; 49 CFR [FR Doc. 2016–29813 Filed 12–12–16; 8:45 am] I. Background
parts 171–180) limited the internal
BILLING CODE 4910–60–P
volume of a DOT–39 specification A key component of PHMSA’s
cylinder to 75 in3 (1.23 L) when used for pipeline safety regulations is its
certain liquefied flammable compressed integrity management (IM) program. For
gases. This size limitation applied when gas transmission pipelines, this program
DOT–39 cylinders were used for gases is outlined in Subpart O of 49 CFR part
that were subject to Note 9 following the 192 and is based on the concept that
table at § 173.304(a)(2) or liquefied pipeline operators need to identify those
pmangrum on DSK3GDR082PROD with NOTICES

1 NPRM—Hazardous Materials: Requirements for
petroleum gas as addressed in segments of their pipeline systems that
DOT Specification Cylinders (HM–220D) [63 FR
§ 173.304(d)(3) (The table is currently pose the greatest risk to human life,
58460].
located at § 173.304a). 2 Final Rule—Hazardous Materials: Requirements
property, and the environment, and to
In an October 30, 1998 notice of for Maintenance, Requalification, Repair and Use of
take extra precautions to ensure their
proposed rulemaking (NPRM), the DOT Specification Cylinders (HM–220D) [67 FR safety. These higher-risk areas are
Research and Special Programs 51625] known as ‘‘HCAs.’’ Each operator is
Administration (RSPA)—the 3 https://www.gpo.gov/fdsys/pkg/FR-2016-07-26/ required to survey its entire pipeline
predecessor agency to PHMSA— pdf/2016-16689.pdf. system to identify all pipeline segments

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Federal Register / Vol. 81, No. 239 / Tuesday, December 13, 2016 / Notices 90063

that could affect HCAs. Since the guidance to gas transmission operators which varies for other gases depending
greatest risk posed by gas transmission on the steps PHMSA expected them to upon their heat of combustion.3
pipelines is the risk of fire and take to determine ‘‘identified sites’’ Following the publication of the
explosion resulting from pipeline leaks along their pipelines. PHMSA intended regulations and advisory bulletin,
and ruptures, gas HCAs consist of the guidance in the advisory bulletin to PHMSA inspections have revealed that
highly populated areas and ‘‘identified support operators in identifying these operators may need further guidance
sites’’ where people regularly gather or sites for planning their IM programs and regarding the identification of HCAs, as
live. determined that certain measures, if operators have been inconsistent in
An operator’s first step in developing properly applied, would satisfy the determining HCAs using ‘‘identified
a robust IM program is to properly intent of the regulation. sites.’’
identify and map all HCAs and perform On December 15, 2003, (68 FR 69778) Additionally, in CY 2015, the
periodic updates to the evaluation PHMSA published a final rule titled: National Transportation Safety Board
process to maintain accurate and ‘‘Pipeline Integrity Management in High (NTSB) published SS–15–01, ‘‘Safety
current information. Subpart O of part Consequence Areas (Gas Transmission Study: Integrity Management of Gas
192 allows operators flexibility in Pipelines)’’ that provided requirements Transmission Pipelines in High
making determinations to identify HCAs for the identification of HCAs and Consequence Areas.’’ The study was
by defining two different identification further explanation of how best to conducted in response to concerns
methods, generally referred to as conduct the identification process. about deficiencies in operators’ IM
Method 1 or Method 2. programs that had been identified by the
Both methods require the operator to In the preamble of the rule, PHMSA
provided the basis for defining an NTSB in three gas transmission pipeline
determine ‘‘identified sites’’ and accidents from the previous 5 years.
calculate a PIR, using a formula to identified site as follows:
Define an identified site as any of the Recommendation P–15–06, issued as a
calculate the radius of a circle within part of the study, recommended that
which the potential failure of a pipeline following within a Potential Impact
Circle: PHMSA ‘‘[a]ssess the limitations
could have significant impact on people associated with the current process for
or property. While Method 1 includes 1. A facility housing persons of
identifying high consequence areas, and
all pipe segments within Class 3 and limited mobility that is known to public
disseminate the results of [the]
Class 4 locations1 and ‘‘identified areas safety officials, emergency response
assessment to the pipeline industry,
within a PIR in Class 1 and 2 locations,’’ officials, or local emergency planning
inspectors, and the public.’’ PHMSA has
Method 2 includes ‘‘identified sites’’ 2 committee, and which meets one of the
noted that proper identification of an
within a PIR only, regardless of the class following three criteria: (a) Is visibly
HCA and periodic verification relies on
location, or the combination of marked, (b) is licensed or registered by
two key types of information: (1)
‘‘identified sites’’ with 20 or more a Federal, state, or local agency, or (c)
Pipeline-specific information that
buildings intended for human is listed on a map maintained by or
includes the accurate location of the
occupancy. available from a Federal, State, or local
centerline of the pipeline, the nominal
A review of PHMSA and state data agency, or
diameter of the pipeline, and the
from ‘‘first-round’’ IM inspections 2. An outdoor area where people pipeline segment’s MAOP; and (2) all
indicates a large percentage of intrastate congregate that is known to public the structures and their usage (including
and small operators have been safety officials, emergency response occupancy) located along the pipeline.
inconsistent in determining HCAs using officials or local emergency planning PHMSA subject matter experts
‘‘identified sites,’’ and operators that committee and which is occupied by 20 performed an assessment of the impact
initially used Method 1 to identify or more people on at least 50 days per of these two issues on identifying HCAs
HCAs have since transitioned to Method year, or using Methods 1 and 2 as defined in
2. 3. A building occupied by 20 or more § 192.903, by reviewing failure
On July 17, 2003, (68 FR 42458) people 5 days per week, 10 weeks in investigations, inspector experiences,
PHMSA published an advisory bulletin any 12-month period (the days and and Gas IM inspection results and has
titled ‘‘Identified Sites as Part of High weeks need not be consecutive). documented these insights in this
Consequence Areas for Gas Integrity To assist operators in meeting the advisory bulletin. PHMSA will be
Management Programs’’ to provide requirements of the regulation, PHMSA including these insights in updated
1 Under 49 CFR 192.5, all transmission pipelines
introduced a ‘‘buffer zone’’ concept. inspection materials, as appropriate.
fall into one of four ‘‘class locations.’’ Class 1 This additional safety margin was PHMSA is publishing this advisory
locations are offshore areas and all segments (‘‘class intended to compensate for inaccuracies bulletin to meet NTSB Recommendation
location units’’) one mile in length that contain 10 (e.g., incorrect pipeline center data or P–15–06 by providing operators with
or fewer buildings intended for human occupancy mapping errors) when implementing the
Class 2 locations are units with more than 10, but
additional guidance on how to improve
fewer than 46, such buildings. Class 3 locations are regulation and determining the PIR. As the accuracy of their class location
units with 46 or more buildings or an area where defined in § 192.903, a PIR is the radius identification process, which may also
the pipeline lies within 100 yards of either a of the potential impact circle (PIC), lead to operators improving HCA
building or a small, well-defined outside area (such measured in feet surrounding the point
as a playground or recreation area) that is occupied
identification.
by 20 or more people on at least 5 days a week for of failure, within which the potential
10 weeks in any 12-month period. Class 4 locations failure of a pipeline could have 3 Operators transporting gas other than natural gas
are units where buildings with 4 or more stories are significant impact on people or
pmangrum on DSK3GDR082PROD with NOTICES

must use section 3.2 of ASME/ANSI B31.8S
prevalent. property. Part 192 provides the formula (incorporated by reference, see § 192.7) to calculate
2 ‘‘Identified sites’’ is a defined term under 49 the impact radius formula. For flammable gases,
CFR 192.903 in PHMSA’s IM regulations and refers
for determining a PIR that takes into additional information on factors may be found in
generally to the type of specific areas included account the Maximum Allowable TTO–13, Potential Impact Radius Formulae for
under the Class 3 location definition above, plus Operating Pressure (MAOP) in the Flammable Gases Other Than Natural Gas Subject
facilities occupied by persons who are confined, are pipeline segment in pounds per square to 49 CFR 192, June 2005, Table 7.1 which can be
of impaired mobility, or would be difficult to found in http://primis.phmsa.dot.gov/gasimp/docs/
evacuate, including schools, prisons, nursing
inch, the nominal diameter of the TTO13_PotentialImpactRadius_FinalReport_
homes, etc. pipeline in inches, and a numeric factor, June2005.pdf).

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Document Created: 2016-12-13 02:44:36
Document Modified: 2016-12-13 02:44:36

Category		Regulatory Information
Collection		Federal Register
sudoc Class		AE 2.7: GS 4.107: AE 2.106:
Publisher		Office of the Federal Register, National Archives and Records Administration
Section		Notices
Action		Notice; Issuance of Advisory Bulletin.
Contact		Allan Beshore by phone at 405-834-8344 or email at [email protected] All materials in this docket may be accessed electronically at http://www.regulations.gov. Information about PHMSA may be found at http://www.phmsa.dot.gov.
FR Citation		81 FR 90062

81 FR 90062 - Pipeline Safety: High Consequence Area Identification Methods for Gas Transmission Pipelines

DEPARTMENT OF TRANSPORTATIONPipeline and Hazardous Materials Safety Administration

Federal Register Volume 81, Issue 239 (December 13, 2016)

DEPARTMENT OF TRANSPORTATION
Pipeline and Hazardous Materials Safety Administration