# Alaska Gas Development Corporation – AGDC — Pipeline Special Permit

**Citation:** PHMSA-2017-0045  
**Type / status:** permit / current  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** 2019-09-09  
**Published:** 2019-09-09

PHMSA-2017-0045, issued 2019-09-09 for Alaska Gas Development Corporation – AGDC's gas transmission system.

## Document text

PHMSA pipeline special permit PHMSA-2017-0045. Operator: Alaska Gas Development Corporation – AGDC. System: Gas Transmission. Issue date: 2019-09-09.

<<<PAGE 1>>>

C
U.S. Department
of Transportation
Pipeline and Hazardous
Materials Safety
Administration
Mr. Frank T. Richards, P.E.
Senior Vice President, Program Management
Alaska Gasline Development Corporation
3201 C Street, Suite 200
Anchorage, Alaska 99503
SEP 9 2Q19 1200 New Jersey Avenue, SE
Washington, D.C. 20590
Docket No. PHMSA-2017-0045
Dear Mr. Richards:
On April 14, 2017, Alaska Gasline Development Corporation (AGDC) requested the Pipeline
and Hazardous Materials Safety Administration (PHMSA) to issue a special permit to waive
compliance from 49 Code of Federal Regulations (CFR) 192.197(a)(4) for the Alaska LNG
Pipeline. The Alaska LNG Pipeline is an 807-mile 42-inch diameter natural gas transmission
pipeline that AGDC has proposed to build extending from the AGDC's proposed Gas Treatment
Plant (GTP) on the North Slope of Alaska to the Liquefaction Facility on the shore of the Cook
Inlet near Nikiski, Alaska, including an offshore pipeline section crossing the Cook Inlet.
PHMSA is granting this special permit (enclosed) for the 42-inch diameter Alaska LNG
Pipeline. This special permit provides relief from the Federal Pipeline Safety Regulations for
the AGDC special permit segments and requires ADGC to comply with certain conditions and
limitations designed to maintain pipeline safety. AGDC is authorized to design, construct, and
operate the Alaska LNG pipeline with mainline block valve spacing of up to 50 miles in the
very sparsely populated region north of Fairbanks borough in Alaska, and up to 30 miles
spacing south of Fairbanks in Class 1 locations. Section 192.179(a)(4) requires a maximum
Class 1 location valve spacing of 20-miles.
PHMSA grants this special permit based on the findings set forth in the "Special Permit
Analysis and Findings" and the "Final Environmental Assessment and Finding ofNo
Significant Impact" documents, which can be read in their entirety in Docket No. PHMSA-
20 17-0045 in the Federal Docket Management System (FDMS) located at
www.regulations.gov.

<<<PAGE 2>>>

My staff would be pleased to discuss this matter or any other regulatory matter with you.
John Gale, Director of Standards and Rulemaking Division may be contacted at
202-366-0434, on regulatory matters, and Sentho White, Director of Engineering and Research
Division, may be contacted at 202-493-2415, on technical matters specific to this special permit
grant.
Sincerely,
A.bL'
Associate Administrator for Pipeline Safety
Enclosure: Special Permit- PHMSA-2017-0045
SEP-
9 201t9
PHMSA-2017-0045-Alaska LNG Pipeline- MLBV Spacing- LOD Page 2 of 2

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U.S. DEPARTMENT OF TRANSPORTATION
PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION
SPECIAL PERMIT- Mainline Valve Spacing
Special Permit Information:
Docket Number:
Requested By:
Operator ID#:
Original Date Requested:
Original Issuance Date:
Effective Date:
Code Sections:
PHMSA-2017-0045
Alaska Gasline Development Corporation
40015
April 14, 2017
September 9, 2019
September 9, 2019
49 CFR 192.179(a)(4)
Grant of Special Permit:
By this order, subject to the terms and conditions set forth below, the United States Department
of Transportation, Pipeline and Hazardous Materials Safety Administration (PHMSA), Office of
Pipeline Safety (OPS),1 grants this special permit to Alaska Gasline Development Corporation
(AGDC), owner and operator of the Alaska LNG Pipeline.2 This special permit waives
compliance from 49 Code of Federal Regulations (CFR) 192.179(a)(4) for sectionalizing
mainline valve spacing in Class 1 locations. This special permit requires the use of remote
controlled valves (RCV) or automatic shut-off valves (ASV) for the Alaska LNG Pipeline and
mandates specific design, construction, operations, and maintenance procedures in accordance
with the special permit conditions.
1 Throughout this special permit, the usage of"PHMSA" or "PHMSA OPS" means the U.S. Department of
Transportation's Pipeline and Hazardous Materials Safety Administration, Office of Pipeline Safety.
2 As used in these draft conditions, the term Alaska LNG Pipeline refers to the approximately 807 miles of 42-inch
natural gas transmission pipeline and not to any potential owners, operators or entities associated with the Alaska
LNG Pipeline. The special permit owner, operator, and applicant/permittee names is Alaska Gasline
Development Corporation. Please note that this pipeline does not transport liquefied natural gas (LNG). It will
supply natural gas to a liquified natural gas (LNG) facility for further transportation as LNG
PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
Page 1 of 16

<<<PAGE 2>>>

I. Purpose and Need:
The Alaska LNG Pipeline will be approximately 807 miles of 42-inch-diameter steel pipe for
transporting natural gas from AGDC's gas treatment plant (GTP) on Alaska's North Slope to the
liquefaction facility on the eastern shore ofthe Cook Inlet near Nikiski, Alaska. The pipeline
will be mostly onshore, with a segment of offshore pipeline crossing the Cook Irdet. The
onshore portion of the pipeline will be a buried pipeline except for short, above-ground special
design segments, such as aerial water crossings and aboveground fault crossings. The Alaska
LNG Pipeline's design has a maximum allowable operating pressure (MAOP) of 2,075 pounds
per square inch gauge (psig).
AGDC is requesting a waiver of compliance with 49 CFR 192.179(a)(4) for remote, sparsely
populated segments along the 42-inch pipeline route. AGDC's special permit request is
specifically for the Class 1 location segments.3
Federal pipeline safety regulations require natural gas transmission pipeline operators to have
sectionalizing block valves within 10 miles of each point on the pipeline (or no more than 20
miles between sectionalizing mainline valves) in a Class 1 location. AGDC' s request allows for
a valve spacing greater than 20 miles in Class 1 locations but requires all ofthe mainline valves
to be either RCVs or ASVs.
II. Special Permit Segment:
State of Alaska
The Alaska LNG Pipeline specialpermit segment is defined as: approximately 807 miles of 42-
inch diameter pipeline originating in the North Slope Borough, traversing the Yukon-Koyukuk
Census Area, the Fairbanks North Star Borough, the Denali Borough, the Matanuska-Susitua
Borough, and the Kenai Peninsula Borough. The specialpermit segment terminates at the
liquefaction facility on the shore of the Cook Inlet near Nikiski, Alaska.
The special permit allows alternative mainline valve placement in Class 1 locations on the 42-
inch specialpermit segment with the implementation ofthe special permit conditions.
49 CFR 192.5 defines Class location units and class 1, 2, 3, and 4 locations.
PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
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PHMSA hereby grants this special permit for the specialpermit segment based on the findings
set forth in the "Final Environmental Assessment and Findings ofNo Sign ficant Impact"
documents, which both can be read in their entirety in Docket No. PHMSA-2017-0045 in the
Federal Docket Management System (FDMS) located on the internet at www.regulations.gov.
III. Conditions:
PHMSA grants this special permit to AGDC for alternative mainline valve spacing subject to
AGDC implementing the following conditions on the specialpermit segment as detailed below:
1. Applicable Regulations: The specialpermit segment must be designed, constructed,
operated, and maintained in accordance with 49 CFR Part 192, including but not limited to,
those requirements that are stated as pertaining to alternative MAOP (49 CFR 192.112,
192.328, and 192.620), but with exception of the mainline valve spacing requirement 49 CFR
192.179(a)(4). In addition to 49 CFR Part 192 conformance, the specialpermit segment
must also be designed, constructed, operated and maintained in accordance with the special
permit conditions.
2. Maximum Allowable Operating Pressure (MAOP): AGDC must operate the special
permit segment at or below a maximum allowable operating pressure (MAOP) of 2,075
pounds per square inch gauge (psig). The specialpermit segment may be designed for
operation up to 80% of specified minimum yield strength, allowing for pressure build-up and
overpressure protection in accordance with 49 CFR 192.620(e).
Mainline Valve Spacin2, Control. Closure, Operations & Maintenance:
3. Transmission Line Valves: Sectionalizing block valves along the specialpermit segment
must be spaced as shown in Table i4 and as follows for class location segments:5
a) Class 1 locations north of Fairbanks from Mile Post 0.00 to Mile Post 422 must have a
50-mile maximum sectionalizing block valve spacing between block valves (each point
on the pipeline must be within 25 miles of a sectionalizing block valve).
"IfAGDC determines that the sectionalizing block valve spacing or operational controls (RCV or ASV), as shown
in Table 1 need to be modified, AGDC must submit proposed changes to the conditions and Table ito PHMSA's Western
Region Director or PWv1SA Project Designee for review and a "no objection" letter must be received prior to the change by
AGDC.
Transmission line class locations are defined in 49 CFR 192.5.
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Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing

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4. b) Class 1 locations south of Fairbanks from Mile Post 422 to Mile Post 807 must have a
30-mile maximum sectionalizing block valve spacing between block valves (each point
on the pipeline must be within 15 miles of a sectionalizing block valve).
c) Class 2, 3, and 4 locations between Mile Post 0.00 to Mile Post 807 must comply with the
requirements of 49 CFR 192.179.6
d) High consequence areas (as defined in 49 CFR 192.903 and 192.905) located in Class 1
and 2 locations, must comply with the requirements of 49 CFR 192.179.
Valve Monitoring, Control and Closure: All mainline valves7 within the specialpermit
segment must be controlled by a supervisory control and data acquisition (SCADA)
system and must be equipped for remote monitoring and control, or remote monitoring and
automatic control, in accordance 49 CFR 192.620(d)(3)(iii), and the below requirements:
a. b. c. d. If any crossover or lateral pipe for gas receipts or deliveries connects to the isolated
segment between the upstream and downstream mainline valves, the nearest valve
on the crossover connection(s) or lateral(s) must be isolated, such that, when all
valves are closed, there is no flow path for gas to flow to the leak or rupture site
(except for residual gas already in the shut-off segment);
All interconnect and/or meter and regulator stations must be monitored and capable
of remote operation for isolating from the pipeline such that, when all valves are
closed, there is no flow path for gas to flow to the leak or rupture site (except for
residual gas already in the shut-off segment);
Mainline valves must be continuously monitored for valve status (open, closed, or
partial closed/open), upstream pressure, and downstream pressure;
Closure of the appropriate valves following a pipeline leak or rupture meeting the
criteria of Condition 4 must occur as soon as practicable from the time the
6 Mile Post 0.00 to Mile Post 807 is the starting and ending mile posts ofthe specialpermit segment. Ifthe length
ofthe pipeline length should change due to routing or survey changes, these mile posts must be adjusted based
upon these changes.
Both RCV and ASV are permissible at sectionalizing mainline valves locations. RCV's must be installed at all
powered and teleconnnunications-equipped locations, that are: compressor, heater and metering locations.
PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
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<<<PAGE 5>>>

pipeline leak or rupture location is confirmed, not to exceed 30 minutes from such
confirmation;8
i. "Rupture" means a significant breach of a pipeline that results in a large-
volume, uncontrolled release of gas, over a short period oftime as defined
below. For purposes ofthis special permit, AGDC must treat all the
following as ruptures:
1. Specialpermit segment pressure drops to 75% of the operating
pressure at the sectionalizing mainline valve based upon maximum
flow model gradients for the upstream compressor station discharge
at MOP (2050 psig). In addition, ASV set-points must not be less
than that required to actuate the valve before a downstream RCV
actuates;9
2. A release of gas observed or reported to the operator by its field
personnel, nearby pipeline or utility personnel, the public, local
responders, or public authorities, and that may be representative of
an unintentional and uncontrolled release event defined in
3. 4. paragraphs (3) or (4) ofthis definition;
An unanticipated or unplanned pressure loss of 10 percent or greater,
occurring within a time interval of 15 minutes or less, unless the
operator has documented in advance of the pressure loss the need for
a higher pressure-change threshold due to pipeline flow dynamics
that cause fluctuations in gas demand that are typically higher than a
pressure loss of 10 percent in a time interval of 15 minutes or less; or
An unexplained flow rate change, pressure change, instrumentation
indication, or equipment function that may be representative of an
event defined in paragraph (2) of this definition.
8 The pipeline valve section location to be closed and isolated (ifthere should be a leak or rupture) must be
confirmed by AGDC through Gas Control or other field operations personnel monitoring ofthe appropriate
pipeline pressures, pressure changes, or flow rate changes through a compressor discharge section, meter stations,
or by location confirmation from responsible persons.
9AGDC must notify the PHMSA Western Region Director in writing ofthe reasons the pressure drop cannot be met
and obtain a letter of"no objection" from PHMSA prior to implementing any pressure drop below 75% of
maximum operating pressure based upon pressure loss through flow gradient.
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Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing

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e. f. Note: Rupture identification occurs when a rupture, as defined in
this section, is observed by or reported to pipeline operating
personnel or a controller.
ii. Within five (5) minutes ofthe initial notification to AGDC, AGDC must
evaluate and identify a rupture, as defined above, as being either an actual
leak event, rupture event or non-rupture event in accordance with operating
procedures and 49 CFR 192.615. Once a rupture is verified, closure of the
appropriate valves must comply with the timing requirements of Condition
4(d).
The Alaska LNG PipelineGas Control Center must monitor the pipeline 24 hours
a day, 7 days a week, and must confirm the existence of a leak or rupture as soon
as practicable in accordance with Condition 4(d);
AGDC must maintain remote monitoring and automatic control equipment,
mainline valves, mainline valve operators, and pressure sensors in accordance
with 49 CFR 192.63 1 and 192.745. All remote monitoring and automatic control
equipment including pressure sensors must have backup power to maintain
communications and control to the AGDC Gas Control Center during power
outages;
g. AGDC must conduct a point-to-point verification between SCADA displays and
the mainline valve, sensors, and communications equipment in accordance with 49
CFR 192.63 1(c) and (e);
h. All valves used to isolate a leak or rupture must be maintained in accordance with
this special permit and 49 CFR 192.745;
i. AGDC must take remedial measures to correct any valve used to isolate a leak or
rupture that is found to be inoperable or unable to maintain shut-off, as follows:
i. Repair or replace the valve as soon as practicable, but no later than six (6)
months after the finding;
ii. Designate an alternative valve within seven (7) calendar days of the
finding while repairs are being made; and
iii. If valve repair or replacement cannot be met due to circumstances
beyond AGDC's control, AGDC must notify the PHMSA Western
Region Director or Project Designee in writing of the reasons the
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Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing

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schedule cannot be met and obtain a letter of "no objection" from
PHMSA prior to implementing the schedule change.
5. Mainline Valve Locations: Mainline valves will be sited per Table 1:
Table 1: Mainline Valve Locations for Alaska LNG_Pipeline'0
MLBV # MP A MJ Location Description Valve
Type
Class
Location(s)
HCA
Yes/No
1 0.00 GTP Meter Station RCV 1 No
2 36.74 36.74 Stand-alone MLBV- Potential Station ASV 1 No
3 75.97 39.23 Compressor Station- Sagwon RCV 1 No
4 112.04 36.07 Stand-alone MLBV- Potential Station ASV 1 No
5 148.51 36.47 Compressor Station- Galbriath Lake RCV 1 No
6 194.09 45.58 Stand-alone MLBV- Potential Station ASV 1 No
6 194.09 45.58 Stand-alone MLBV- Potential Station ASV 1 No
7 240.10 46.01 Compressor Station- Coldfoot RCV 1 No
8 286.05 45.95 Stand-alone MLBV- Potential Station ASV 1 No
9 332.64 46.59 Compressor Station- Ray River RCV I No
9A 356.22 23.58 Added for potential "Hotspot Café" HCA ASV I No
10 377.95 21.78 Stand-alone MLBV- Potential Station ASV 1 No
11 421.56 43.61 Compressor Station- Minto RCV 1 No
12 444.90 23.34 Stand-alone MLBV ASV 1 No
13 467.10 22.20 Stand-a1oneMLBV-PotentialStation ASV 1 No
14 492.96 25.86 Stand-alone MLBV ASV 1 No
15 517.62 24.66 CompressorStation -Healy RCV 1 No
16 534.79 17.17 Upstream of Class 3 Location- Nenana Canyon ASV 1 No
17 538.79 4.00 Downstream of Class 3 Location- Nenana Canyon ASV 1 No
18 546.50 7.71 Stand-alone MLBV- Potential Station ASV 1 No
19 572.23 25.73 Stand-alone MLBV ASV 1 No
20 597.35 25.12 Compressor Station- Honolulu Creek RCV I No
21 625.83 28.48 Stand-alone MLBV ASV I No
22 648.16 22.33 Stand-alone MLBV- Potential Station ASV I No
23 675.24 27.08 Compressor Station- Rabideux Creek RCV I No
24 703.67 28.43 Stand-alone MLBV- Potential Station ASV I No
25 725.93 22.26 Stand-alone MLBV- Potential Station ASV I No
26 749.11 23.18 Heater Station- Theodore River RCV 1 No
° Sectionalizing mainline valve siting is based upon the latest route revision C2 and may be subject to change with
future route alternatives. The final siting will follow the requirements and limitations ofthe special permit
conditions.
PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
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Table 1: Mainline Valve Locations for Alaska LNG_Pipeline10
MLBV # MP A MP Location Description Valve
Type
Class
Locajons3
HCA
Yes/No
27 766.01 16.90 UpstreamofCooklnletcrossing ASV 1 No
28 793.34 27.33 Downstream of Cook Inlet crossing RCV 1 No
29 799.85 6.51 Stand-alone MLBV- Potential Class 2 Location RCV 2 No
30 806.57 6.72 LNG Meter Station RCV 1 No
6. Emergency Operations:
a) Alaska LNG Pipeline control center operators must continually monitor position and
operational status of all RCVs affected by a leak/rupture event until positive isolation
ofthe effected segment is confirmed.
b) AGDC must immediately and directly notify the appropriate public safety access
point (9-1-1 emergency call center) or other coordinating agency for the communities
and jurisdictions in which the pipeline is located when a release is indicated.
c) AGDC must establish actions required to be taken by a pipeline controller, or the
appropriate emergency response coordinator, during an emergency in accordance
with these special permit conditions and as required in 49 CFR 192.615 and 192.631.
d) Emergency closure drills simulating shutting down a randomly selected section of
transmission line must be performed at least once in a calendar year, but within an
interval not to exceed 15 months. AGDC may conduct a table-top emergency closure
drill to meet this requirement for no more than two out of each three calendar years.
The operator will conduct a site-specific emergency closure drill at a field site at least
once every three calendar years.
7. Emergency Training and Planning: AGDC must develop and implement emergency
response plans and procedures for the specialpermit segment in accordance with 49 CFR
192.6 15 and the following requirements:
a. Identify the appropriate public safety access point (911 emergency call center), fire,
police, and other public officials to be notified;
AGDC must designate the pipeline controller or the appropriate operator emergency response coordinator in its
operating procedures and train the pipeline controller or the appropriate operator emergency response
coordinator for coordinating with emergency responders.
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Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing

<<<PAGE 9>>>

b. c. Identify responsibility, resources, jurisdictional area, and emergency contact telephone
numbers for both local and out-of-area calls of each government organization that may
respond to a pipeline emergency; and
Inform emergency officials (911 emergency call centers, fire, police, and other public
officials) about the operator's ability to respond to the pipeline emergency and means of
communication.
d. Emergency response plans must be reviewed, updated and communicated, as required
in this Condition 7 and 49 CFR 192.615(b) and (c), on a calendar year basis, not to
exceed 15 months.
Reportin2 and Certification:
8. Annual Reports: Within twelve (12) months following pipeline start-up'2 and annually13
thereafter, AGDC must report the following to the PHMSA Western Region Director or
Project Designee, with copies to the Director, PHMSA Engineering and Research
Division, and Director, PHMSA Standards and Rulemaking Division:'4' 15
a) The number of new residences, identified sites, or other structures intended for human
occupancy and public gathering areas built within a potential impact radius (PIR) of
the specialpermit segment, as defined in 49 CFR 192.903;
b) Any reportable incidents associated with the specialpermit segment that occurred
during the previous year;
c) Any emergency events that cause closure of mainline valves as described in
Condition 4, including the location (mile post) of valves and closure times;
d) Any emergency drills performed in accordance with Condition 6(d). Submit a brief
description of the emergency drill and date of the drill; and
12 Pipeline start-up is defined as an interval during which the pipeline system begins operations, and throughput
(product flow through the pipeline) is ramped to commercial capacity.
13 Annual reports must be received by PHMSA by the last day ofthe month of pipeline start-up. For example, the
annual report for pipeline start-up beginning March 7, 2021, must be received by PHMSA no later than March
3 1S each year beginning in 2022.
14 Upon notice to the AGDC, PHMSA may update reporting contacts for Condition 7.
' AGDC must place a copy of each Alaska LNG Pipeline annual report on the PHMSA docket, PRMSA-20 17-
0045, at www.regulations.gov.
PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
Page 9 of 16

<<<PAGE 10>>>

e) Any company mergers, acquisitions, transfers of assets, or other events affecting the
regulatory responsibility of the company operating the pipeline to which this special
permit applies.
9. Notifications: AGDC must notify the PHMSA UPS Western Region Director or Project
Designee, at least 14 days prior to conducting field activities associated with the special
permit segment to meet Conditions 6(d).
10. Certification:
a) A senior executive officer of AGDC, vice president or higher, must certify in writing
that:
b) c) i. The specialpermit segment meets the conditions described in this special permit
(including applicable sections 49 CFR 192.112, 192.328, and 192.620 for
alternative MAOP) and other applicable sections of 49 CFR Part 192; and
ii. The written manual of O&M procedures required by 49 CFR 192.605 for the
Alaska LNG Pipeline includes all additional operating and maintenance
requirements of this special permit and 49 CFR Part 192;
The certification must be sent to PHMSA within three (3) months ofplacing the
Alaska LNG Pipeline into natural gas service.
AGDC must send a copy of the certifications required in this condition, with
completion dates, compliance documentation summary, and the required senior
executive signature and date of signature to the PHMSA Associate Administrator for
Pipeline Safety, with copies to the Deputy Associate Administrator for Pipeline
Safety, PHMSA Field Operations; Deputy Associate Administrator, PHMSA Policy
and Programs; PHMSA Western Region Director; Director, PHMSA Standards and
Rulemaking Division; Director, PUMSA Engineering and Research Division; and to
the Federal Register Docket (PHMSA-2017-0045) at www.regulations.gov.
11. AGDC may propose changes to these special permit conditions by making a request to
PHMSA in writing. Any proposed changes to the conditions by AGDC must maintain
equivalent levels of safety, as determined by PHMSA. PHMSA will determine whether
substantive changes to the conditions require a modification or public notice ofthis special
permit. PHMSA will provide AGDC with notice of its decision and an opportunity to
PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
Page 10 of 16

<<<PAGE 11>>>

respond to any PHMSA-proposed changes to AGDC's request in accordance with 49 CFR
190.341. Any submittal timing, review timing, or completion timing in these conditions can
be modified by PHMSA upon request by AGDC and with a "no objection" letter from
PHMSA'6 to AGDC.
IV. Limitations:
This special permit is subject to the limitations set forth in 49 CFR 190.34 1 as well as the
following limitations:
1) PHMSA has the sole authority to make all determinations on whether AGDC has complied
with the specified conditions of this special permit for the Alaska LNG Pipeline. Failure to
comply with any condition ofthis special permit may result in revocation ofthe permit.
2) Any work plans and associated schedules for the Alaska LNG Pipeline supporting this
special permit are automatically incorporated into this special permit and are enforceable in
the same manner.
3) Failure by AGDC to submit the certifications required by Condition 10 (Certification)
within the time frames specified may result in revocation ofthis special permit.
4) As provided in 49 CFR 190.341, PHMSA may issue an enforcement action for failure to
comply with this special permit for the Alaska LNG Pipeline. The terms and conditions
of any corrective action order, compliance order or other order applicable to a pipeline
facility covered by this special permit will take precedence over the terms ofthis special
permit.
5) If AGDC sells, merges, transfers, or otherwise disposes of all or part of the assets known as
the Alaska LNG Pipeline, AGDC must provide PHMSA with written notice of the change
within 30 days of the consummation date. In the event of such transfer, PHMSA reserves the
right to revoke, suspend, or modify the special permit ifthe transfer constitutes a material
change in conditions or circumstances underlying the permit.
16 AGDC must submit any proposed changes to the conditions to PHMSA Western Region Director or PHIMSA
project designee for review and a letter of "no objection" prior to usage.
PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
Page 11 of 16

<<<PAGE 12>>>

AUTHORITY: 49 U.S.C. 60118 and 49 CFR 1.97.
SEP 9 2019
Issued in Washington, DC on
AIbJJ
Associate Administrator for Pipeline Safety
Figure 1: Alaska LNG Pipeline Route
PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
Page 12 of 16

<<<PAGE 13>>>

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PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
Page 13 of 16

<<<PAGE 14>>>

Table 2: Mainline Valve Locations for Alaska LNG Pipeline with High Consequence Areas, Bridges, and
Railroad Locations
MLBV MP.
A MP, miles. . .
Location Description Valve Class HCA
Type Location(s) Yes/No
1 0.00 GTP Meter Station RCV 1 No
2 36.74 36.74 Stand-alone MLBV- Potential Station ASV 1 No
3 75.97 39.23 Compressor Station- Sagwon RV No
4 112.04 36.07 Stand-alone MLBV- Potential Station ASV No
5 148.51 36.47 Compressor Station- Gaibriath Lake RCV 1 No
6 194.09 45.58 Stand-alone MLBV- Potential Station ASV 1 No
6 194.09 45.58 Stand-alone MLBV- Potential Station ASV 1 No
236.08 to 1.25 HCA -Marion Campground- 1.25 miles 1 Yes
7 240.10 46.01 Compressor Station- Coldfoot RCV 1 No
8 286.05 45.95 Stand-alone MLBV- Potential Station ASV No
9 332.64 46.59 Compressor Station- Ray River RCV No
352.21 to 1.14 HCA-Hotspot Café 1 Yes
9a 356.22 23.58 Added for potential "Hotspot Café" HCA ASV 1 No
10 377.95 21.73 Stand-alone MLBV- Potential Station ASV 1 No
11 421.56 43.61 Compressor Station- Minto RCV 1 No
12 444.90 23.34 Stand-alone MLBV ASV 1 No
13 467.10 22.20 Stand-alone MLBV- Potential Station ASV 1 No
14 492.96 25.86 Stand-alone MLBV ASV 1 No
15 517.62 24.66 COmpressorStation -Healy RCV 1 No
529.21 to 1.23 HCA-RV Park and Hotel- 1.23 miles 1 Yes
532.07 Alaska Railroad Crossing No
532.13 Nenana River Bridge Crossing No
16 534.79 17.17 Upstream of Class 3 Location- Nenana Canyon ASV 1 No
HCA- Denali Riverside RV Park, McKinley Chalet
Resort, Denali Rainbow Village and RV, Denali
535 54 0.45 Princess Wilderness Lodge, Denali Crows Nest 1 Yes
990 Cabins, Grarid Denali Lodge, and Denali Bluffs Hotel
-2.20 miles
HCA- Denali Riverside RV Park, McKinley Chalet
535 99 Resort, Denali Rainbow Village and RV, Denali
536 49 0.50 Princess Wilderness Lodge, Denali Crows Nest 3 Yes
Cabins, Grand Denali Lodge, and Denali Bluffs Hotel
-2.20 miles
HCA- Denali Riverside RV Park, McKinley Chalet
536 49 Resort, Denali Rainbow Village and RV, Denali
537 1.25 Princess Wilderness Lodge, Denali Crows Nest 1 Yes
Cabins, Grand Denali Lodge, and Denali Bluffs Hotel
-2.20 miles
PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
Page 14 of 16

<<<PAGE 15>>>

Table 2: Mainline Valve Locations for Alaska LNG Pipeline with High Consequence Areas, Bridges, and
Railroad Locations
MLBV Valve Class HCA
# MP A MP, miles. .
Location Description Type Location(s) Yes/No
537.79 Lynx Creek Bridge Crossing 1 Yes
17 538.79 4.00 Downstream of Class 3 Location- Nenana Canyon ASV 1 No
18 546.50 7.71 Stand-alone MLBV- Potential Station ASV 1 No
551.34 to 0.93 HCA- Denali Perch Resort- 0.93 miles 1 Yes
565.77 to 1.46 HCA- DOT/PF Cantwell Station- 1.46 miles 1 Yes
19 572.23 25.73 Stand-alone MLBV ASV No
572.79 Alaska Railroad Crossing 1 No
588.07 Alaska Railroad Crossing 1 No
20 597.35 25.12 Compressor Station- Honolulu Creek RCV 1 No
609.02 Alaska Railroad Crossing 1 No
21 625.83 28.48 Stand-alone MLBV ASV 1 No
629.75 to 1 60 HCA-Byers Lake Campground (73 units)- 1.60 1 Yes
631.35 miles
633.75 to 0.75 HCA- Trappers Creek Pizza Club -0.75 miles 1 Yes
22 648.16 22.33 Stand-alone MLBV- Potential Station ASV 1 No
23 675.24 27.08 Compressor Station- Rabideux Creek RCV 1 No
24 703.67 28.43 Stand-alone MLBV- Potential Station ASV 1 No
25 725.93 22.26 Stand-alone MLBV- Potential Station ASV 1 No
26 749.11 23.18 Heater Station- Theodore River RCV 1 No
27 766.01 16.90 UpstreamofCooklnletcrossing ASV 1 No
28 793.34 27.33 Downstream of Cook Inlet crossing RCV 1 No
HCA-Nikiski Middle/High School, Kenai Heliport,
797 71 0.94 Commercial Buildings, and Industrial Sites- 1.57 1 Yes
798 65 miles
HCA-Nikiski Middle/High School, Kenai Heliport,
798 65 0.63 Commercial Buildings, and Industrial Sites- 1.57 2 Yes
799 28° miles
799.28 to 1.99 2 No
801.27
29 799.85 6.51 Stand-alone MLBV- Potential Class 2 Location RCV 2 No
803.39 to HCA- Conoco Phillips Property and Tesoro Kenai
803.78 0 39 Refinery -2.66 miles I Yes
803.78 to HCA- Conoco Phillips Property and Tesoro Kenai 2
806.05 2 27 Refinery -2.66 miles Yes
806.05 to 0.20 2 No
806.25
PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
Page 15 of 16

<<<PAGE 16>>>

Table 2: Mainline Valve Locations for Alaska LNG Pipeline with High Consequence Areas, Bridges, and
Railroad Locations
MLBV I Valve I Class HCA
# MP
I A MP, miles
i Location Description
I Type Location(s) Yes/No
30 806.57 6.72 LNG Meter Station RCV 1 No
PHMSA-2017-0045: Alaska Gasline Development Corporation Alaska LNG Pipeline- Special Permit for Mainline Valve Spacing
Page 16 of 16

<<<PAGE 1>>>

U.S. DEPARTMENT OF TRANSPORTATION
PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION
Mainline Block Valve Spacing
Special Permit Analysis and Findings
Special Permit Information:
Docket Number: PHMSA-2017-0045
Requested By: Alaska Gasline Development Corporation
Operator ID#: 40015
Original Date Requested: April 14, 2017
Original Issuance Date: September 9, 2019
Effective Dates: September 9, 2029
Code Section(s): 49 CFR 192.179(a)(4)
Purpose:
The Pipeline and Hazardous Materials Safety Administration (PHMSA)1 provides information to
describe the facts of the subject special permit application submitted by the Alaska Gasline
Development Corporation (AGDC), owner and operator of the Alaska LNG Pipeline,
2 to discuss any
relevant public comments received with respect to the application for a special permit, to present the
engineering/safety analysis, and to make public the findings regarding whether the requested special
permit should be granted and if so under what conditions. AGDC requested a special permit for the
Alaska LNG Pipeline to waive compliance from 49 Code of Federal Regulations (CFR)
192.179(a)(4) for sectionalizing mainline block valve spacing in Class 1 locations in Alaska.
1 Throughout this special permit the usage of “PHMSA” or “PHMSA OPS” means the U.S. Department of
Transportation’s Pipeline and Hazardous Materials Safety Administration Office of Pipeline Safety.
2 Alaska LNG Pipeline refers to the approximately 807 miles of 42-inch natural gas transmission pipeline and not to any
potential owners, operators, or entities associated with the Alaska LNG Pipeline. The special permit owner, operator,
and applicant/permittee is Alaska Gasline Development Corporation. Please note that this pipeline does not transport
liquefied natural gas (LNG). It will supply natural gas to a LNG facility for further transportation as LNG.
PHMSA-2017-0045 - - Alaska Gasline Development Corporation Alaska LNG Pipeline – Special Permit Analysis & Findings
Page 1 of 11

<<<PAGE 2>>>

Pipeline System Affected:
The Alaska LNG Pipeline will be approximately 807 miles of 42-inch-diameter steel pipe for
transporting natural gas from AGDC’s gas treatment plant (GTP) on Alaska’s North Slope to the
liquefaction facility on the eastern shore of the Cook Inlet near Nikiski, Alaska. The pipeline will be
mostly onshore, with a segment of offshore pipeline crossing the Cook Inlet. The onshore portion of
the pipeline will be a buried pipeline except for short, above-ground special design segments, such
as aerial water crossings and aboveground fault crossings. The Alaska LNG Pipeline’s design has a
maximum allowable operating pressure (MAOP) of 2,075 pounds per square inch gauge (psig).
AGDC is requesting a waiver of compliance of 49 CFR 192.179(a)(4) for remote, sparsely populated
segments along the 42-inch pipeline route. AGDC’s special permit request is specifically for the
Class 1 location segments.3
Federal pipeline safety regulations require natural gas transmission pipeline operators to have
sectionalizing block valves within 10 miles of each point on the pipeline (or no more than 20 miles
between sectionalizing mainline valves) in a Class 1 location. AGDC’s request allows for a valve
spacing greater than 20 miles in Class 1 locations but requires all mainline block valves to be either
remote controlled valves (RCVs) or automatic shut-off valves (ASVs).
Special Permit Request:
AGDC requested increased spacing of sectionalizing mainline block valves along the special permit
segment as follows:
Transmission Line Valves: Sectionalizing block valves along the special permit segment must
be spaced as shown in Tables 1 and 24 and as follows for class location segments:
a) Class 1 locations north of Fairbanks from Mile Post 0.00 to Mile Post 422 must have a 50-
mile maximum sectionalizing block valve spacing between block valves (each point on the
pipeline must be within 25 miles of a sectionalizing block valve).
3 49 CFR 192.5 defines Class location units and class 1, 2, 3, and 4 locations.
4 If AGDC determines that the sectionalizing block valve spacing or operational controls (RCV or ASV) as shown in
Table 1 need to be modified, AGDC must submit proposed changes to the conditions and Table 1 to PHMSA’s Western Region
Director or PHMSA Project Designee for review, and a “no objection” letter must be received prior to the change by AGDC.
PHMSA-2017-0045 - - Alaska Gasline Development Corporation Alaska LNG Pipeline – Special Permit Analysis & Findings
Page 2 of 11

<<<PAGE 3>>>

b) Class 1 locations south of Fairbanks from Mile Post 422 to Mile Post 807 must have a 30-
mile maximum sectionalizing block valve spacing between block valves (each point on the
pipeline must be within 15 miles of a sectionalizing block valve).
c) Class 2, 3, and 4 locations between Mile Post 0.00 to Mile Post 807 must comply with the
requirements of 49 CFR 192.179.
d) High consequence areas (as defined in 49 CFR 192.903 and 192.905) located in Class 1 and
2 locations, must comply with the requirements of 49 CFR 192.179.
PHMSA designed a comprehensive set of special permit conditions that AGDC is required to
implement in order to operate the 42-inch diameter pipeline with an increased mainline block valve
spacing. An overview of the special permit condition topics is in the Operational Integrity
Compliance section of this document. The special permit conditions were based upon pipeline
safety considerations for the 49 CFR Part 192 sections that AGDC was seeking relief for an
alternative mainline block valve spacing.
The usage of remote controlled valves (RCVs) and automatic shut-off valves (ACVs) will reduce the
time to isolate a pipeline segment should there be a rupture on the pipeline. In remote locations
where it could take over 1 hour to isolate a pipeline segment, the Alaska LNG Pipeline will be able
to isolate a pipeline segment in less than 35 minutes. The time to isolate a mainline block valve
(MLBV) along the special permit segment is shown in Table 2 - MLBV Locations with
Approximate Valve Closure Time and Gas Released.
Special Permit Segment:
State of Alaska
The Alaska LNG Pipeline special permit segment is defined as: approximately 807 miles of 42-inch
diameter pipeline originating in the North Slope Borough, traversing the Yukon-Koyukuk Census
Area, the Fairbanks North Star Borough, the Denali Borough, the Matanuska-Susitna Borough, and
the Kenai Peninsula Borough. The special permit segment terminates at the liquefaction facility on
the shore of the Cook Inlet near Nikiski, Alaska.
The special permit allows alternative mainline valve placement in Class 1 locations on the 42-inch
special permit segment with the implementation of the special permit conditions.
PHMSA-2017-0045 - - Alaska Gasline Development Corporation Alaska LNG Pipeline – Special Permit Analysis & Findings
Page 3 of 11

<<<PAGE 4>>>

Public Notice:
On May 28, 2019, PHMSA published a special permit request in the Federal Register (84 FR 24594)
for public comment. The public comment period ended on July 29, 2019, and PHMSA reviewed
and considered all comments received through July 29, 2019. The special permit application from
AGDC, pipeline route maps, public comments, final environmental assessment and finding of no
significant impact, and special permit conditions are available in Docket No. PHMSA-2017-0045 at:
www.regulations.gov.
PHMSA Overall Response and Considerations of Public Safety Concerns:
PHMSA published a Notice of Availability in the Federal Register on May 28, 2019, for four (4)
special permit requests for the line pipe of the Alaska LNG Pipeline. (84 FR 24594, Docket Nos.:
PHMSA-2017-0046, Usage of 3LPE Coating; PHMSA-2017-0044, Usage of Strain Based Design;
PHMSA-2017-0045, Alternative Mainline Block Valve Spacing; and PHMSA-2017-0047, Usage of
Crack Arrestor Spacing at www.Regulations.gov.) PHMSA requested comment on the special
permit applications, the draft permit conditions, and the draft environmental analyses. The public
notice comment period ended on July 29, 2019, and PHMSA reviewed and considered all comments
received through July 29, 2019. PHMSA received a public comment concerning usage of fossil
fuels, the building of the Alaska LNG Pipeline, and the building of a liquified natural gas (LNG)
facility. PHMSA does not have siting authority over pipeline facilities. The public comment
received did not submit concerns directed towards the special permit, the environmental assessment,
or the special permit conditions, which were the issues within PHMSA’s decision making authority
and the intent of the public notice.
Operational Integrity Compliance:
PHMSA has reviewed this special permit request to ensure that integrity threats to the pipeline in the
special permit segment are addressed in the operator’s operations and management plan (O&M
Procedures and specifications). PHMSA carefully designed a comprehensive set of conditions that
AGDC is required to implement in order to operate the Alaska LNG Pipeline with increased
mainline block valve spacing in Class 1 locations.
PHMSA-2017-0045 - - Alaska Gasline Development Corporation Alaska LNG Pipeline – Special Permit Analysis & Findings
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<<<PAGE 5>>>

The special permit conditions are summarized by topic in the below list. The full conditions can be
reviewed in their entirety in the special permit, which can be reviewed on Docket PHMSA-2017-
0045 at www.regulations.gov.
1) Applicable Regulations
2) Maximum Allowable Operating Pressure
3) Transmission Line Valves
4) Valve Monitoring, Control and Closure
5) Mainline Valve Locations
6) Emergency Operations
7) Emergency Training and Planning
8) Annual Reports
9) Notifications
10) Certification
11) Changes to Special Permit Conditions
12) Limitations
Past Enforcement History:
AGDC has no gas transmission pipeline operating history or enforcement history with PHMSA.
Findings:
Based on the information submitted by AGDC and PHMSA’s analysis of technical, operational, and
safety issues, and given the conditions that will be imposed in the special permit, PHMSA finds that
granting this special permit to AGDC to operate the Alaska LNG Pipeline special permit segment at
increased mainline block valve spacing intervals and with either RCVs or ASVs will not be
inconsistent with pipeline safety.
Completed in Washington DC on: September 9, 2019
Prepared By: PHMSA – Engineering and Research Division
PHMSA-2017-0045 - - Alaska Gasline Development Corporation Alaska LNG Pipeline – Special Permit Analysis & Findings
Page 5 of 11

<<<PAGE 6>>>

Figure 1: ALASKA LNG Pipeline Route
PHMSA-2017-0045 - - Alaska Gasline Development Corporation Alaska LNG Pipeline – Special Permit Analysis & Findings
Page 6 of 11

<<<PAGE 7>>>

Table 1: Mainline Valve Locations for Alaska LNG Pipeline with High Consequence Areas (HCAs),
Bridges, and Railroad Locations
MLBV
# MP  MP, miles Location Description Valve
Type
Class
Location(s)
HCA
Yes/No
1 0.00 GTP Meter Station RCV 1 No
2 36.74 36.74 Stand-alone MLBV - Potential Station ASV 1 No
3 75.97 39.23 Compressor Station - Sagwon RCV 1 No
4 112.04 36.07 Stand-alone MLBV - Potential Station ASV 1 No
5 148.51 36.47 Compressor Station - Galbriath Lake RCV 1 No
6 194.09 45.58 Stand-alone MLBV - Potential Station ASV 1 No
6 194.09 45.58 Stand-alone MLBV - Potential Station ASV 1 No
236.08 to
237.33 1.25 HCA – Marion Campground – 1.25 miles 1 Yes
7 240.10 46.01 Compressor Station - Coldfoot RCV 1 No
8 286.05 45.95 Stand-alone MLBV - Potential Station ASV 1 No
9 332.64 46.59 Compressor Station - Ray River RCV 1 No
352.21 to
353.35 1.14 HCA - Hotspot Café 1 Yes
9a 356.22 23.58 Added for potential “Hotspot Café” HCA ASV 1 No
10 377.95 21.73 Stand-alone MLBV - Potential Station ASV 1 No
11 421.56 43.61 Compressor Station - Minto RCV 1 No
12 444.90 23.34 Stand-alone MLBV ASV 1 No
13 467.10 22.20 Stand-alone MLBV - Potential Station ASV 1 No
14 492.96 25.86 Stand-alone MLBV ASV 1 No
15 517.62 24.66 Compressor Station - Healy RCV 1 No
529.21 to
530.44 1.23 HCA – RV Park and Hotel – 1.23 miles 1 Yes
532.07 Alaska Railroad Crossing 1 No
532.13 Nenana River Bridge Crossing 1 No
16 534.79 17.17 Upstream of Class 3 Location - Nenana Canyon ASV 1 No
535.54 to
535.99 0.45
HCA - Denali Riverside RV Park, McKinley Chalet
Resort, Denali Rainbow Village and RV, Denali
Princess Wilderness Lodge, Denali Crows Nest
Cabins, Grand Denali Lodge, and Denali Bluffs Hotel
– 2.20 miles
1 Yes
535.99 to
536.49 0.50
HCA - Denali Riverside RV Park, McKinley Chalet
Resort, Denali Rainbow Village and RV, Denali
Princess Wilderness Lodge, Denali Crows Nest
Cabins, Grand Denali Lodge, and Denali Bluffs Hotel
– 2.20 miles
3 Yes
PHMSA-2017-0045 - - Alaska Gasline Development Corporation Alaska LNG Pipeline – Special Permit Analysis & Findings
Page 7 of 11

<<<PAGE 8>>>

Table 1: Mainline Valve Locations for Alaska LNG Pipeline with High Consequence Areas (HCAs),
Bridges, and Railroad Locations
MLBV
# MP  MP, miles Location Description Valve
Type
Class
Location(s)
HCA
Yes/No
536.49 to
537.74 1.25
HCA - Denali Riverside RV Park, McKinley Chalet
Resort, Denali Rainbow Village and RV, Denali
Princess Wilderness Lodge, Denali Crows Nest
Cabins, Grand Denali Lodge, and Denali Bluffs Hotel
– 2.20 miles
1 Yes
537.79 Lynx Creek Bridge Crossing 1 Yes
17 538.79 4.00 Downstream of Class 3 Location - Nenana Canyon ASV 1 No
18 546.50 7.71 Stand-alone MLBV - Potential Station ASV 1 No
551.34 to
552.27 0.93 HCA – Denali Perch Resort – 0.93 miles 1 Yes
565.77 to
567.23 1.46 HCA – DOT/PF Cantwell Station – 1.46 miles 1 Yes
19 572.23 25.73 Stand-alone MLBV ASV 1 No
572.79 Alaska Railroad Crossing 1 No
588.07 Alaska Railroad Crossing 1 No
20 597.35 25.12 Compressor Station - Honolulu Creek RCV 1 No
609.02 Alaska Railroad Crossing 1 No
21 625.83 28.48 Stand-alone MLBV ASV 1 No
629.75 to
631.35 1.60 HCA – Byers Lake Campground (73 units) – 1.60
miles 1 Yes
633.75 to
634.50 0.75 HCA – Trappers Creek Pizza Club – 0.75 miles 1 Yes
22 648.16 22.33 Stand-alone MLBV - Potential Station ASV 1 No
23 675.24 27.08 Compressor Station - Rabideux Creek RCV 1 No
24 703.67 28.43 Stand-alone MLBV - Potential Station ASV 1 No
25 725.93 22.26 Stand-alone MLBV - Potential Station ASV 1 No
26 749.11 23.18 Heater Station - Theodore River RCV 1 No
27 766.01 16.90 Upstream of Cook Inlet crossing ASV 1 No
28 793.34 27.33 Downstream of Cook Inlet crossing RCV 1 No
797.71 to
798.65 0.94
HCA – Nikiski Middle/High School, Kenai Heliport,
Commercial Buildings, and Industrial Sites – 1.57
miles
1 Yes
798.65 to
799.28 0.63
HCA – Nikiski Middle/High School, Kenai Heliport,
Commercial Buildings, and Industrial Sites – 1.57
miles
2 Yes
799.28 to
801.27 1.99 2 No
29 799.85 6.51 Stand-alone MLBV - Potential Class 2 Location RCV 2 No
803.39 to
803.78 0.39 HCA – Conoco Phillips Property and Tesoro Kenai
Refinery – 2.66 miles 1 Yes
PHMSA-2017-0045 - - Alaska Gasline Development Corporation Alaska LNG Pipeline – Special Permit Analysis & Findings
Page 8 of 11

<<<PAGE 9>>>

Table 1: Mainline Valve Locations for Alaska LNG Pipeline with High Consequence Areas (HCAs),
Bridges, and Railroad Locations
MLBV
# MP  MP, miles Location Description Valve
Type
Class
Location(s)
HCA
Yes/No
803.78 to
806.05 2.27 HCA – Conoco Phillips Property and Tesoro Kenai
Refinery – 2.66 miles 2 Yes
806.05 to
806.25 0.20 2 No
30 806.57 6.72 LNG Meter Station RCV 1 No
Table 2 - MLBV Locations with Approximate Valve Closure Time and Gas Released
MLBV # MP MP Location Description Valve Type
Approximate
Closure Time
(minutes)5
Approximate
Mass of Gas
Released (tons)6
1 0.00 GTP Meter Station RCV 10.7 14,600
2 36.74 36.74 Stand-alone MLBV -
Potential Station 28.6 14,600
ASV
29.9 15,300
10.7 15,300
3 75.97 39.23 Compressor Station -
Sagwon RCV
10.7 14,400
4 112.04 36.07 Stand-alone MLBV -
Potential Station 28.3 14,400
ASV
28.5 14,500
5 148.51 36.47 Compressor Station -
Galbriath Lake RCV
10.7 14,500
10.7 17,000
6 194.09 45.58 Stand-alone MLBV -
Potential Station 33.1 17,000
ASV
33.3 14,600
7 240.10 46.01 Compressor Station -
Coldfoot 10.7 14,600
RCV
10.7 17,100
8 286.05 45.95 Stand-alone MLBV -
Potential Station ASV
33.3 17,100
33.6 17,200
9 332.64 46.59 Compressor Station - Ray
River RCV
10.7 17,200
10.7 16,900
9A 356.22 23.58 Added for potential
“Hotspot Café” HCA ASV 20.5 11,300
23.7 11,500
10 377.95 21.78 Stand-alone MLBV -
Potential Station ASV
32.9 16,900
32.1 16,500
5 Closure time is the total time measured from leak detection to complete valve closure and full interruption of flow.
6 The mass of gas released is based on a rupture occurring between the adjacent valves using the closure times of the
upstream and downstream valves. Based on the Alaska LNG Pipeline gas composition, there are 45,148 cubic feet per
ton.
PHMSA-2017-0045 - - Alaska Gasline Development Corporation Alaska LNG Pipeline – Special Permit Analysis & Findings
Page 9 of 11

<<<PAGE 10>>>

Table 2 - MLBV Locations with Approximate Valve Closure Time and Gas Released
MLBV # MP MP Location Description Valve Type
Approximate
Closure Time
(minutes)5
Approximate
Mass of Gas
Released (tons)6
10.7 16,500
11 421.56 43.61 Compressor Station - Minto RCV
10.7 10,200
21.8 10,200
12 444.90 23.34 Stand-alone MLBV ASV
20.4 11,200
13 467.10 22.20 Stand-alone MLBV -
Potential Station 20.4 11,200
ASV
22.7 12,700
22.7 12,700
14 492.96 25.86 Stand-alone MLBV ASV
22.5 10,700
10.7 10,700
15 517.62 24.66 Compressor Station - Healy RCV
10.7 7,800
16 534.79 17.17 Upstream of Class 3
Location - Nenana Canyon 18.7 7,800
ASV
9.3 2,300
17 538.79 4.00 Downstream of Class 3
Location - Nenana Canyon ASV
9.3 2,300
11.6 4,400
18 546.50 7.71 Stand-alone MLBV -
Potential Station 11.6 4,400
ASV
22.6 12,700
22.6 12,700
19 572.23 25.73 Stand-alone MLBV ASV
22.7 10,800
20 597.35 25.12 Compressor Station -
Honolulu Creek RCV
10.7 10,800
10.7 12,000
24.4 12,000
21 625.83 28.48 Stand-alone MLBV ASV
20.5 11,300
22 648.16 22.33 Stand-alone MLBV -
Potential Station 20.5 11,300
ASV
23.7 11,500
23 675.24 27.08 Compressor Station -
Rabideux Creek RCV
10.7 11,500
10.7 12,000
24 703.67 28.43 Stand-alone MLBV -
Potential Station ASV
24.4 12,000
20.5 11,300
25 725.93 22.26 Stand-alone MLBV -
Potential Station 20.5 11,300
ASV
21.8 10,100
26 749.11 23.18 Heater Station - Theodore
River 10.7 10,100
RCV
10.7 7,700
27 766.01 16.90 Upstream of Cook Inlet
crossing ASV
18.6 7,700
23.6 13,300
28 793.34 27.33 Downstream of Cook Inlet
crossing RCV
23.6 13,300
10.9 3,700
29 799.85 6.51 RCV 10.9 3,700
PHMSA-2017-0045 - - Alaska Gasline Development Corporation Alaska LNG Pipeline – Special Permit Analysis & Findings
Page 10 of 11

<<<PAGE 11>>>

Table 2 - MLBV Locations with Approximate Valve Closure Time and Gas Released
MLBV # MP MP Location Description Valve Type
Approximate
Closure Time
(minutes)5
Approximate
Mass of Gas
Released (tons)6
Stand-alone MLBV -
Potential Class 2 Location 13.4 3,300
30 806.57 6.72 LNG Meter Station RCV 10.7 3,300
PHMSA-2017-0045 - - Alaska Gasline Development Corporation Alaska LNG Pipeline – Special Permit Analysis & Findings
Page 11 of 11

<<<PAGE 1>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
U.S. DEPARTMENT OF TRANSPORTATION
PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION
Final Environmental Assessment
and
Finding of No Significant Impact
Mainline Block Valve Spacing Special Permit
Special Permit Information:
Docket Number: PHMSA-2017-0045
Requested By: Alaska Gasline Development Corporation
Operator ID#: 40015
Original Date Requested: April 14, 2017
Original Issuance Date: September 9, 2019
Effective Date: September 9, 2019
Code Sections: 49 CFR 192.179(a)(4)
Page 1 of 40

<<<PAGE 2>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Mainline Block Valve
Final Environmental Assessment
This Final Environmental Assessment (FEA) analyzes the Alaska LNG Pipeline for a special
permit to waive the requirements of Title 49 of the Code of Federal Regulations
(CFR) 192.179(a)(4). The special permit request described herein is related to, but distinct from
the Federal Energy Regulatory Commission (FERC) decision making process for siting and
permitting Alaska LNG’s 42-inch pipeline (Mainline) to transport natural gas to a facility on
Alaska’s North Slope. The Pipeline and Hazardous Material Safety Administration (PHMSA)
does not have pipeline siting or construction approval authority, but PHMSA’s pipeline safety
regulations impose certain safety requirements that will apply to the Alaska LNG Pipeline. The
requirements for special permit applications to PHMSA to request waiver from one or more
safety regulations are described at 49 CFR 190.341. This FEA references the Alaska Gasline
Development Corporation’s (AGDC) FERC Resource Reports for the Alaska LNG Pipeline to
avoid duplication. Furthermore, this FEA accompanies AGDC’s special permit request on crack
arrestor spacing. This information can also be found in Appendix C, Environmental Information
for Mainline Block Valve and Crack Arrestor Spacing Special Permit of the Alaska LNG
Pipeline FERC Resource Report No. 11, Reliability and Safety found on the FERC docket CP17-
178, Accession Number 20170417-5342 which can be accessed through
https://elibrary.ferc.gov/IDMWS/common/OpenNat.asp?fileID=14562356.
I. Purpose and Need
AGDC is proposing to construct a 42-inch diameter pipeline as part of an integrated
liquefied natural gas (LNG) project (Project) with interdependent facilities for the purpose
of liquefying supplies of natural gas from Alaska, in particular from the Point Thomson
Unit (PTU) and Prudhoe Bay Unit (PBU) production fields on the Alaska North Slope
(North Slope), for export in foreign commerce and for in-state deliveries of natural gas.
FERC is the lead Federal agency. Pursuant to 49 U.S.C. 60101, et seq and 49 CFR 192,
PHMSA has authority over design, construction, operation, and maintenance of natural
gas pipelines to maintain safety. As noted above, PHMSA does not have pipeline siting
authority or construction approval authority. If required, special permits can be granted
under 49 CFR 190.341 for deviations from the regulatory requirements. PHMSA imposes
conditions on the grant of special permits to assure safety and environmental protection in
accordance with 49 CFR 190.341. PHMSA complies with the National Environmental
Policy Act (NEPA) in deciding whether to issue the special permit.
AGDC is requesting a special permit from PHMSA to waive compliance with 49 CFR
192.179 only in Class 1 locations. AGDC is proposing a mainline block valve (MLBV)
Page 2 of 40

<<<PAGE 3>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
spacing of 50 miles north of Fairbanks, Alaska, and 30 miles south of Fairbanks.
1 The
purpose of MLBVs is to isolate a segment of pipeline in the event of a pipeline failure in
order to stop product flow to the failure site. The spacing of MLBV is defined in 49 CFR
192.179(a) as stated below:
Each transmission line, other than offshore segments, must have sectionalizing
block valves spaced as follows, unless in a particular case the Administrator finds
that alternative spacing would provide an equivalent level of safety:
(4) Each point on the pipeline in a Class 1 location must be within 10 miles (16
kilometers) of a valve.
II. Background and Site Description
The Alaska LNG Pipeline route from the proposed gas treatment plant (GTP) located at
Prudhoe Bay to the proposed LNG Plant site located on the Kenai Peninsula is shown in
Figure 1. The Alaska LNG Pipeline will be a 42-inch-diameter natural gas pipeline,
approximately 807 miles in length, extending from the Alaska LNG’s GTP on the North
Slope, flowing south to the Liquefaction Facility on the shore of the Cook Inlet near
Nikiski, including an offshore pipeline section crossing Cook Inlet. The onshore pipeline
will be a buried pipeline except for short aboveground special design segments, such as
aerial water crossings and aboveground fault crossings. As presented in Table 1.3.2-1 of
FERC Resource Report 1 (inserted below), the Alaska LNG Pipeline will originate in the
North Slope Borough, traverse south to the Yukon-Koyukuk Census Area, the Fairbanks
North Star Borough, the Denali Borough, the Matanuska-Susitna Borough, and the Kenai
Peninsula Borough, and terminate at the Liquefaction Facility. The Alaska LNG
Pipeline’s design has a maximum allowable operating pressure (MAOP) of 2,075 pounds
per square inch gauge (psig).
1 The average Class 1 MLBV spacing north of Fairbanks is about 42 miles, while the average spacing south of
Fairbanks is about 24 miles.
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ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Figure 1: Alaska LNG Pipeline Route Map
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ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
TABLE 1.3.2-1 (From FERC Resource Report 1)
Mainline Route Summary for a 42-inch Pipeline
Segment or
Facility Name Boroughs or Census Areas Approximate Length
(miles)
North Slope Borough 184.4
Yukon-Koyukuk Census Areas 303.8
Fairbanks North Star Borough 2.4
Mainline
Denali Borough 86.8
Matanuska-Susitna Borough 179.9
Kenai Peninsula Borough 51.3
Total 806.6
The Alaska LNG Pipeline will include several types of aboveground pipeline facilities. The
design includes eight (8) compressor stations, four meter stations, multiple pig
launching/receiving stations, multiple MLBVs, and five potential gas interconnection points
(Figure 2 and Figure 3 to this FEA, and FERC Resource Report No. 1, Appendix A). A list
of compressor stations, heater station, and meter stations is provided in Table 1.3.2-6 of
FERC Resource Report 1.
Approximately 36 percent of the Alaska LNG Pipeline route is collocated within 500 feet of:
an existing right-of-way (ROW) that includes the Trans Alaska Pipeline System (TAPS) and
other pipelines; highways or major roads; utilities; and railroads. Table 1.3.2-2 of FERC
Resource Report No. 1 (inserted below) identifies these areas along the pipeline. The Alaska
LNG Pipeline crosses TAPS twelve times and its associated Fuel Gas Line five times,
respectively, along with four railroad crossings. Design of the road and railroad crossings will
determine the minimum wall thickness requirements for service loads in accordance with
American Petroleum Institute (API) Recommended Practice (RP) 1102, and in compliance
with 49 CFR 192.111. The minimum depth of cover will be four (4) feet for road crossings as
specified by the Alaska Administrative Code 17.AAC 15.211 “Underground Facilities”, and
ten feet for railroad crossings as specified in Alaska Railroad Corporation (ARRC) standards.
These values exceed the 49 CFR 192.327 requirement of a minimum of three feet at drainage
ditches of public roads and railroads. Site-specific designs for major highway and railroad
crossings are provided in Appendix H of FERC Resource Report No. 1, General Project
Description, and in the table below:
Bridge and Railroad Crossings
Milepost (MP) Crossing Type Description
532.13 Bridge Nenana River at Moody
537.90 Bridge Lynx Creek
532.07 Railroad Alaska Railroad Mainline
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ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
572.79 Railroad Alaska Railroad Mainline
588.07 Railroad Alaska Railroad Mainline
609.02 Railroad Alaska Railroad Mainline
Additional details on roads, railroads, pipelines, utilities, and power line crossings can be
found in FERC Resource Report No. 8, Land Use, Recreation, and Aesthetics.
TABLE 1.3.2-2 (From FERC Resource Report No. 1)
Collocated ROWs with the Mainline (within 500 feet)
Borough/Census Area Category Length (Miles) Length (Feet)
North Slope Borough
Trans-Alaska Pipeline System (TAPS) 24.39 128,768
Other Pipelinesa 34.83 183,904
Highways or Major Roadsb 59.97 316,630
Utilities 108.65 573,692
Railroads – –
Yukon-Koyukuk Census Area
TAPS 64.14 338,653
Other Pipelinesa
– –
Highways or Major Roadsb 94.13 496.985
Utilities 106.42 561.898
Railroads 0.83 4,405
Denali Borough
TAPS – –
Other Pipelinesa 0.09 453
Highways or Major Roadsb 13.25 69,984
Utilities 46.21 243,983
Railroads 1.00 5,283
Matanuska-Susitna Borough
TAPS –
–
Other Pipelinesa 2.31 12,206
Highways or Major Roadsb 26.76 141,289
Utilities 29.76 157,157
Railroads 2.30 12,123
Kenai Peninsula Boroughc
TAPS –
–
Other Pipelinesa 3.37 17,810
Highways or Major Roadsb 1.58 8,342
Utilities 0.02 130
Railroads –
–
Total Collocation Opportunities 289.58 1,528,971
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ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Aerial crossings on pipeline specific bridges (i.e. bridges that carry only a pipeline) are
located at Nenana River at Moody and Lynx Creek. The design factor for the pipeline at
aerial crossings will comply with 49 CFR § 192.111 (i.e., the design factor in Class 1
Locations will be 0.60).
Pipeline design standards in 49 CFR 192.5(a)(1) are based on “class location units,” which
classify locations based on population density in the vicinity of an existing or proposed
pipeline system. The lower the class location (1-4), the higher the design factor used to
find the minimum required wall thickness for pressure containment, i.e. the required
minimum thickness of the pipe increases as the Class location and population density
increases. Ninety-nine percent of the Alaska LNG Pipeline route is in Class 1, which is
defined as having 10 or fewer buildings intended for human occupancy located within 220
yards on either side of any continuous 1-mile length of pipeline. On the Kenai Peninsula,
near Nikiski, there is a Class 2 location that is about 2.6 miles long, and a potential Class 3
location as the Mainline nears the LNG Plant. In the Nenana Canyon region of Denali
National Park (~milepost [MP] 536) there is approximately 0.5 mile of Class 3.
Additional details on class locations for the Mainline can be found in FERC Resource
Report No. 11, Reliability and Safety, Section 11.7. Resource Report No. 11 and Table
11.7.2-1 identifying class locations for the pipeline route is reproduced below.
TABLE 11.7.2-1 (From FERC Resource Report No. 11)
Class Locations for the Mainline
Milepost (MP)
Start
(MP)
End
(MP)
Class Location
0.00 535.99 1
535.99 536.49 3
536.49 798.65 1
798.65 801.27 2
801.27 803.78 1
803.78 806.25 2
806.25 806.57 1
There are 10 potential high consequence areas (HCA), as defined under 49 CFR 192.903, along
the Alaska LNG Pipeline route. Details of HCA locations can be found in FERC Resource
Report No. 11, Section 11.7, Table 11.7.4-1 (shown below with insertions for mainline valve
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ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
locations and valve type), Table 1, Table 2, and Attachment D - Main Line Block Valve Spacing
Technical Support document2 of the MLBV spacing special permit application.
TABLE 11.7.4-1 (From FERC Resource Report No. 11) –
with insertions for mainline valve locations and type
Potential HCA Takeoff for Proposed Route
From MP To MP Length
(mi.)
Description
0.00 MLBV 1, GTP Meter Station
36.74 MLBV 2, Automatic Shut-off Valve (ASV)
75.97 MLBV 3, Remote Controlled Valve (RCV)
112.04 MLBV 4, ASV
148.51 MLBV 5, RCV
194.09 MLBV 6, ASV
236.08 237.33 1.25 Marion Creek Campground
240.1 MLBV 7, RCV
286.05 MLBV 8, RCV
332.64 MLBV 9, RCV
352.21 353.35 1.14 Hotspot Cafe
356.22 MLBV 9A, ASV
377.95 MLBV 10, ASV
421.56 MLBV 11, RCV
444.90 MLBV 12, ASV
467.10 MLBV 13, ASV
492.96 MLBV 14, ASV
517.62 MLBV 15, RCV
529.21 530.44 1.23 RV Park and Motel
534.79 MLBV 16, ASV
535.54 537.74 2.20 Denali Riverside RV Park, McKinley Chalet Resort,
Denali Rainbow Village and RV, Denali Princess
Wilderness Lodge, Denali Crow’s Nest Cabins, Grand
Denali Lodge, Denali Bluffs Hotel
538.79 MLBV 17, ASV
546.50 MLBV 18, ASV
551.34 552.27 0.93 Denali Perch Resort
565.77 567.23 1.46 DOT/PF Cantwell Station
572.23 MLBV 19, ASV
597.35 MLBV 20, RCV
2 Attachment D can be found in www.regulations.gov in Docket PHMSA-2017-0045.
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ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
625.83 MLBV 21, ASV
629.75 631.35 1.60 Byers Lake Campground (73 units)
633.75 634.50 0.75 Trappers Creek Pizza Pub
648.16 MLBV 22, RCV
675.24 MLBV 23, ASV
703.67 MLBV 24, ASV
725.93 MLBV 25, RCV
749.11 MLBV 26, ASV
766.01 MLBV 27, ASV
793.34 MLBV 28, RCV
797.71 799.28 1.57 Nikiski Middle/High School, Kenai Heliport, Commercial
Buildings, Industrial Sites
799.85 MLBV 29, RCV
803.39 806.05 2.66 Conoco Phillips Property and Tesoro Kenai Refinery
806.57 MLBV 30, LNG Meter Station
HCA Total Length 14.79
In addition, the pipeline route special permit segments addressed in the special permit for
Strain Based Design (SBD) segments, will be incorporated into the integrity management
program (IMP), and treated as covered segments in HCA, in accordance with 49 CFR Part
192, Subpart O, and the associated special permit conditions, if the special permit for
Strain Based Design is granted by PHMSA.
The construction ROW width will vary depending on the type of terrain, the season of
construction, and the ease of access from nearby roads. The ROW width will be 50 feet
plus the diameter of the pipeline, i.e. 53.5 feet. At MLBV locations the ROW width will
expand to approximately 85 feet over lengths of approximately 100 feet. If a helipad
associated with any MLBV location is deemed necessary, an additional section of
expanded ROW (approximately 115 feet wide by approximately 115 feet long) will be
required. See FERC Resource Report No. 1, General Project Description, Appendix E,
drawing E-102 for further details of the overall arrangement. Greater details on the
construction ROW can be found in FERC Resource Report No. 1, General Project
Description. The Mainline will be sited on land composed of more than 85 percent
Federal, State of Alaska, and borough land of various holdings, with the remainder on
privately owned land (see FERC Resource Report No. 8, Land Use, Recreation and
Aesthetics).
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ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Environmental Setting
The corridor for the Alaska LNG Pipeline spans nine ecoregions including the Beaufort
Coastal Plain, Brooks Foothills, Brooks Range, Kobuk Ridges and Valleys, Ray Mountains,
Yukon-Tanana Uplands, Tanana-Kuskokwim Lowlands, Alaska Range, and Cook Inlet
Basin. These regions host a variety of ecosystems including muskeg bogs, spruce upland
forest, alpine and Arctic tundra, high brush, and bottomland spruce and poplar forests. The
associated ecosystems support a variety of species which include grizzly and black bears,
Arctic foxes, seals, caribou, moose, small terrestrial mammals, birds, and anadromous fish.
A variety of marine mammals inhabit the coastal waters along the pipeline ROW, including
the bowhead whale, polar bear, beluga whale, ringed seal, bearded seal, Stellar sea lion,
harbor seal, ribbon seal and spotted seal. Some of these species are critical subsistence
resources for Alaska Native peoples. For additional information see FERC Resource Report
No.3, Fish, Wildlife and Vegetation Resources.
A detailed description of the Alaska LNG Pipeline ROW is included in Section 1.3.2.1 of
FERC Resource Report No. 1, General Project Description. Supporting facilities are
described in Section 1.3.2.1.3 and temporary construction infrastructure is described in
Section 1.3.2.4 of FERC Resource Report No. 1, General Project Description. Baseline
environmental conditions and the analysis of environmental effects resulting from
construction and operation of the Alaska LNG Pipeline are addressed in the individual
FERC Resource Reports which can be accessed by entering the FERC Docket Number
“CP17-178” at https://elibrary.ferc.gov/IDMWS/common/OpenNat.asp?fileID=14562356
and then opening the Accession Number of the FERC filing for that Resource Report.
Direct links to the Accession File for each Resource Report are given below:
a) Resource Report No. 1 (General Project Description) 20170417-5337.
https://elibrary.ferc.gov/idmws/file_list.asp?document_id=14561634
b) Resource Report No. 2 (Water Use and Quality) 20170417-5341.
https://elibrary.ferc.gov/idmws/file_list.asp?document_id=14561641
c) Resource Report No. 3 (Fish, Wildlife and Vegetation) 20170417-5351.
https://elibrary.ferc.gov/idmws/file_list.asp?document_id=14561657
d) Resource Report No. 4 (Cultural Resources) 20170417-5336.
https://elibrary.ferc.gov/idmws/file_list.asp?document_id=14561631
e) Resource Report No. 5 (Socioeconomics) 20170417-5338.
https://elibrary.ferc.gov/idmws/file_list.asp?document_id=14561635
f) Resource Report No. 6 (Geological Resources) 201704167-5338.
https://elibrary.ferc.gov/idmws/file_list.asp?document_id=14561635
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ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
g) Resource Report No. 7 (Soils) 20170417-5345.
https://elibrary.ferc.gov/idmws/file_list.asp?document_id=14561645
h) Resource Report No. 8 (Land Use, Recreation and Aesthetics) 20170417-5345.
https://elibrary.ferc.gov/idmws/file_list.asp?document_id=14561645
i) Resource Report No. 9 (Air and Noise Quality) 20170417-5345.
https://elibrary.ferc.gov/idmws/file_list.asp?document_id=14561645
j) Resource Report No. 10 (Alternatives) 20170417-5340
https://elibrary.ferc.gov/idmws/file_list.asp?document_id=14561638
k) Resource Report No. 11, (Reliability and Safety) 20170417-5342.
https://elibrary.ferc.gov/idmws/file_list.asp?document_id=14561642
Description of Special Permit Needs
As stated above, the Applicant is seeking exemption from the requirements for MLBV
spacing requirements in 49 CFR 192.179 in Class 1 locations. Additional details on class
locations for the Alaska LNG Pipeline can be found in FERC Resource Report No. 11,
Reliability and Safety, Section 11.7.
The Alaska LNG Pipeline will traverse areas of high environmental value commonly used
for outdoor recreation, sporting, and subsistence activities. It is possible that individuals
could be in the vicinity of the pipeline even if there are 10 or fewer buildings intended for
human occupancy located within 220 yards on either side of any continuous 1-mile length
of pipeline. However, as the engineering analysis has shown, the proposed alternative to
MLBV spacing will not expose these individuals or infrastructure to any risk greater than
a 49 CFR Part 192 compliant design, as a result of additional mitigation measures
designed to reduce risk to the public and nearby infrastructure.
III. Alternatives
An applicant requesting a special permit from PHMSA has the option of building a
pipeline that will not require PHMSA to issue a special permit. This will require the
design, construction, and operation of a pipeline in compliance with all requirements of 49
CFR Part 192. Therefore, PHMSA’s NEPA assessment is slightly different form other
agencies in that the “No Action” alternative is not a “no build” alternative. Rather, the No
Action alternative reflects a pipeline design that will not require issuance of a special
permit. The “Proposed Action” alternative reflects the Applicant’s increase of MLBV
spacing for which a special permit with specific conditions will be issued. The two
alternatives are described below.
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<<<PAGE 12>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
No Action Alternative – Design, construct, operate and maintain the pipeline in
compliance with 49 CFR Part 192. This will require MLBVs to be placed at intervals
defined by 49 CFR 192.179(a)(4). A 20-mile maximum spacing is required in Class 1
locations.
Proposed Action Alternative – Design, construct, operate, and maintain the pipeline with
MBLV spacing at longer intervals than allowed by 49 CFR 192.179(a)(4), and design,
construct, operate, and maintain the pipeline in compliance with the MLBV spacing
special permit conditions.
AGDC is requesting a special permit from PHMSA to allow for increased MLBV spacing,
in low risk, Class 1 locations. This special permit contains conditions that will require
enhanced monitoring of MLBVs with shorter valve activation times as compared to a
design that is compliant to 49 CFR 192. The valves will include a combination of Remote
Controlled Valves (RCV) and Automatic Shut-off Valves (ASV), both with pressure set
points that will initiate automatic closure. In addition, the RCVs will be capable of remote
operation (closure and opening) along with pressure monitoring, both upstream and
downstream of the valve that is reported to a pipeline control center. Due to the faster
response and the valves, any failure will result in equivalent gas release for the first 17.5
minutes following the failure. Thereafter, the shorter valve closure times required in the
special permit will result in less gas released and lower thermal radiation factors. The
below Figure 1A shows RCV and ASV closure times versus manual valve closure times.
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<<<PAGE 13>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Figure 1A – Gas Outflow as a Function of Time
The special permit conditions are designed to provide for equal or greater pipeline safety
than a pipeline constructed in accordance with 49 CFR Part 192.
a. Explain what the special permit application asks for.
The special permit will increase MLBV spacing up to 50 miles north of Fairbanks
and 30 miles South of Fairbanks from the requirement in 49 CFR 192.179(a)(4),
which requires MLB spacing of up to 20 miles in Class 1 locations.
i. Cite regulation(s) for which special permit is sought in accordance with 49 CFR
190.341:
49 CFR 192.179(a)(4).
ii. Explain/summarize how the design/operation/maintenance of the pipeline
operating under the special permit would differ from the pipeline in the no action
alternative.
There will be two (2) types of MLBVs utilized for line break detection and
sectionalization: RCVs will be installed at all powered locations (i.e. compressor
and heater stations), and ASVs will be installed at other locations. The ASVs willPage 13 of 40

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ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
automatically close based on either a pressure set point of 75% of the operating
pressure at the valve location based upon maximum flow model gradients, or a
decrease in operating pressure over a fifteen (15) minute period that is greater
than approximately 10%, as these conditions will likely indicate a line break.
Functionality will be added to the RCVs to allow the pipelines gas control center
to remotely close these valves in an emergency when deemed safe to do so. The
ASVs will close based on the 75% of maximum operating pressure (MOP) at the
valve location based upon maximum flow model gradients. In addition, ASV set
points shall not be less than that required to actuate the valve before a downstream
RCV. Once activated, both types of valves will close in less than one (1) minute.
Approximate closure times and gas release volumes for each valve-to-valve
section are presented in Table 1 – MLBV Locations. These requirements are
intended to result in a reduction of valve closure actuation times as compared to a
49 CFR Part 192 compliant design. Real time monitoring of the RCVs via the
Supervisory Control and Data Acquisition (SCADA) system will be performed at
the Alaska LNG Pipeline Control Center. Additional detail on the requirements
for design, construction, and operation is provided in Section VII of this
document and the special permit conditions.
iii. Applicant should include the pipeline stationing and mile posts (MP) for the
location or locations of the applicable special permit segment(s)
Details of the MLBV locations are presented in Table 1 – MLBV Locations.
Maps showing the MLBV locations and other information are presented in Figure
2 and Figure 3.
3
Table 1 MLBV Locations
MLBV # MP MP Location Description Valve Type
Approximate
Closure Time
(minutes)4
Approximate Mass
of Gas Released
(tons)5
1 0.00 GTP Meter Station RCV 10.7 14,600
2 36.74 36.74 Stand-alone MLBV -
Potential Station 28.6 14,600
ASV
29.9 15,300
3 Estimated time to begin activation of a manual mainline valve, if the “No Action Alternative” is selected, is two
hours with another 30 minutes to close the valve.
4 Closure time is the total time measured from leak detection to complete valve closure and full interruption of flow.
5 The mass of gas released is based on a rupture occurring between the adjacent valves using the closure times of
the upstream and downstream valves. Based on the Alaska LNG Pipeline gas composition, there are 45,148 cubic
feet per ton.
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<<<PAGE 15>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Table 1 MLBV Locations
MLBV # MP MP Location Description Valve Type
Approximate
Closure Time
(minutes)4
Approximate Mass
of Gas Released
(tons)5
10.7 15,300
3 75.97 39.23 Compressor Station -
Sagwon RCV
10.7 14,400
4 112.04 36.07 Stand-alone MLBV -
Potential Station 28.3 14,400
ASV
28.5 14,500
5 148.51 36.47 Compressor Station -
Galbriath Lake RCV
10.7 14,500
10.7 17,000
6 194.09 45.58 Stand-alone MLBV -
Potential Station 33.1 17,000
ASV
33.3 14,600
7 240.10 46.01 Compressor Station -
Coldfoot RCV
10.7 14,600
10.7 17,100
8 286.05 45.95 Stand-alone MLBV -
Potential Station 33.3 17,100
ASV
33.6 17,200
9 332.64 46.59 Compressor Station - Ray
River 10.7 17,200
RCV
10.7 16,900
9A 356.22 23.58 Added for potential
“Hotspot Café” HCA ASV 20.5 23.7 11,300
11,500
10 377.95 21.78 Stand-alone MLBV -
Potential Station 32.9 16,900
ASV
32.1 16,500
10.7 16,500
11 421.56 43.61 Compressor Station - Minto RCV
10.7 10,200
21.8 10,200
12 444.90 23.34 Stand-alone MLBV ASV
20.4 11,200
13 467.10 22.20 Stand-alone MLBV -
Potential Station 20.4 11,200
ASV
22.7 12,700
22.7 12,700
14 492.96 25.86 Stand-alone MLBV ASV
22.5 10,700
10.7 10,700
15 517.62 24.66 Compressor Station - Healy RCV
10.7 7,800
16 534.79 17.17 Upstream of Class 3
Location - Nenana Canyon ASV
18.7 7,800
9.3 2,300
17 538.79 4.00 Downstream of Class 3
Location - Nenana Canyon 9.3 2,300
ASV
11.6 4,400
18 546.50 7.71 Stand-alone MLBV -
Potential Station ASV
11.6 4,400
22.6 12,700
19 572.23 25.73 Stand-alone MLBV ASV 22.6 12,700
Page 15 of 40

<<<PAGE 16>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Table 1 MLBV Locations
MLBV # MP MP Location Description Valve Type
Approximate
Closure Time
(minutes)4
Approximate Mass
of Gas Released
(tons)5
22.7 10,800
20 597.35 25.12 Compressor Station -
Honolulu Creek 10.7 10,800
RCV
10.7 12,000
24.4 12,000
21 625.83 28.48 Stand-alone MLBV ASV
20.5 11,300
22 648.16 22.33 Stand-alone MLBV -
Potential Station ASV
20.5 11,300
23.7 11,500
23 675.24 27.08 Compressor Station -
Rabideux Creek RCV
10.7 11,500
10.7 12,000
24 703.67 28.43 Stand-alone MLBV -
Potential Station 24.4 12,000
ASV
20.5 11,300
25 725.93 22.26 Stand-alone MLBV -
Potential Station 20.5 11,300
ASV
21.8 10,100
26 749.11 23.18 Heater Station - Theodore
River RCV
10.7 10,100
10.7 7,700
27 766.01 16.90 Upstream of Cook Inlet
crossing 18.6 7,700
ASV
23.6 13,300
28 793.34 27.33 Downstream of Cook Inlet
crossing RCV
23.6 13,300
10.9 3,700
29 799.85 6.51 Stand-alone MLBV -
Potential Class 2 Location 10.9 3,700
RCV
13.4 3,300
30 806.57 6.72 LNG Meter Station RCV 10.7 3,300
Page 16 of 40

<<<PAGE 17>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Figure 2: Valve Location Map
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<<<PAGE 18>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Figure 3: Valve Location Map (Nenana Canyon)
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<<<PAGE 19>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
i. Mitigation Measures
Additional mitigation measures are addressed in Section VIII of this document
and the special permit conditions.
RCVs and ASVs to be used on the Alaska LNG Pipeline are identical in material
and construction but differ with respect to the logic systems within the valve
actuators connected to the valves. In both cases, the RCVs and ASVs will be
large diameter ball valves meeting API 6D requirements and will be controlled by
valve actuators. The valve actuators are gas-hydraulic powered, using line gas
pressure to open/close the valves. The ASV’s will be configured to close
automatically, utilizing energy stored in the valve actuator, when the gas pressure
in the pipeline is below the valve close set point. An auxiliary device, such as a
hand pump, may be required to reopen a valve after a closure event. RCV’s will
be shut-in from the gas control center.
The ASVs use mechanical systems to constantly compare the line pressure on
either side of the valve to a pre-set value (75% MOP for the Alaska LNG
Pipeline) and should the line pressure drop below this set point the valve will
close. The use of purely mechanical and hydraulic systems for ASVs means they
can operate without the need for electrical power in the event of a line break.
Actuators on RCVs will include the same internal mechanical/hydraulic logic
systems as the ASVs but will additionally incorporate power-controlled solenoids
(switches) to signal the valve to close when a computer-controlled system sends
an alternate signal to the valve based on other criteria. AGDC will implement
procedures that a decrease in operating pressure over a fifteen (15) minute period
of greater than approximately 10% MOP will cause mainline valves to be closed
to isolate the applicable pipeline segment. RCVs can also be closed by a signal
from the pipeline control center should the need arise, such as when an
observation of a leak or rupture6 is reported.
IV. Environmental Impacts of Proposed Action and Alternatives
a. Describe how a small and large leak/rupture to the pipeline could impact safety and the
environment/human health.
6 Definitions for “leak” or “rupture” vary. However, the project defines a “leak” as a release from a stable through-
wall defect, and “rupture” as a release where the defect expands under the influence of the applied stress after
become through-wall.
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Potential impacts of small and large pipeline leaks/ruptures to the environment/human
health apply equally to the Proposed Action and No Action alternatives because:
i. Any discussion of the consequence of a leak or rupture must be put into the
context of its probability. It is highly unlikely a leak or rupture occurring over the
Alaska LNG Pipeline Class 1 locations will impact the environment or human
health for the following reasons:
a) Remoteness of the pipeline route: more than 99% of the Alaska LNG Pipeline
route is in Class 1 location (801 miles of 806.6 miles). The frequency of
incidents is significantly less for pipelines in Class 1 locations than in Class 2,
3 or 4. Specifically, the number of incidents per 1,000 mile-years in Class 1
locations was 0.15 as compared with 0.24 and 0.65 for Class 2 and Class 3
and 4 locations, respectively.
7 The lower incident rate in Class 1 locations is
attributed to fewer incidences of outside force damage in these lesser
populated areas.
b) Resilience to third party mechanical damage: given the planned thickness of
the pipe wall, there is very low risk of mechanical damage. Fracture
mechanics calculations based on the mechanical properties of the pipe
material and operating conditions of the pipe have shown the pipe is very
resistant to puncture and fracture, capable of withstanding a through wall
thickness flaw of greater than 4 inches in length without rupturing.
c) Very low probability of corrosion damage: The Alaska LNG Pipeline will be
transporting a dry, LNG specification gas, which will contain no significant
quantities of the microbial species required to cause corrosion: water (< 0.1
lbs./MMSCF), CO2 (<50 ppmv) and H2S (≤4 ppmv). With these low impurity
contents, a corrosive liquid water phase will not form inside the pipeline.
Therefore, the probability of internal corrosion is minimal. To ensure the
integrity of the pipeline, the in-line inspection program will comply with the
robust requirements of 49 CFR 192.620(d)(9) and (10). External corrosion
will be mitigated by using a high-integrity coating with a cathodic protection
system.8
d) Compliance with Alternative MAOP requirements: the entire Alaska LNG
Pipeline will be operated and maintained per 49 CFR 192.620, which
7 Eiber, R., and Kiefner, J. 2010. Review of Safety Considerations for Natural Gas Pipeline Block Valve Spacing.
ASME Standards Technology, LLC. Columbus. July.
8 See Alaska LNG Pipeline FEA for special permit request for use of 3LPE Coating. [Docket PHMSA-2017-0046 at
www.regulations.gov]
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establishes robust operational requirements. Additionally, more than 615
miles of the total Mainline length, to include Alternative MAOP and SBD
segments, will also comply with 49 CFR 192.112 and 192.328, which,
respectively, establish robust design and construction requirements.
e) AGDC performed an engineering study that considered requirements from
ASME B31.8 § 846.1 for block valve spacing, including consideration of “the
amount of gas released due to repair and maintenance blowdowns, leaks, or
ruptures.” The analysis results, summarized in Attachment D - Main Line
Block Valve Spacing Technical Support document, suggest “that increased
valve spacing could be implemented in remote, low population density areas
without affecting safety” because, as the thermal radiation analysis
demonstrated, there is a negligible difference in the potential consequence to
people in Class 1 locations, where there is an extremely low density of
buildings intended for human occupancy. Incident prevention (decreasing
probability of rupture) is better controlled through other practices, such as
design for fracture resistance and control, and robust integrity management
practices that include in-line inspections.9
ii. A small leak from a buried pipeline would result in a much slower release of gas
than a full-bore rupture, with the total amount of gas released being dependent on
the time it takes for the leak to be detected and fixed. Small leaks would be
identified through a variety of techniques, such as routine surveillance, pipeline
inspection programs, and mass balance systems incorporated in gas pipeline
control. These identification techniques are not impacted by mainline block valve
spacing. Gas from a small leak would permeate up through the pipeline backfill
material (soil) before dissipating into the air. An individual small leak is not a
significant source of methane emissions, although such leaks in the aggregate can
be. Also, small gas pipeline leaks may result in some impacts to, or loss of,
surrounding vegetation. This localized browning of vegetation can facilitate
identification of small underground leaks during ROW inspection, which will be
performed at intervals not exceeding 45 days but a least 12 times each calendar
year per 49 CFR 192.620(d)(4). The rate at which gas is lost, and total volume of
gas lost from a small leak is independent of valve spacing and is more contingent
on identification timelines. The environmental impacts caused from a small leak
are the same in both the Proposed Action and No Action alternatives.
9 See Alaska LNG Pipeline FEA for special permit request for Crack Arrestor Spacing. [Docket PHMSA-2017-0047
at www.regulations.gov].
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iii. A pipeline rupture would result in the rapid release of a large volume of natural
gas, resulting in significant damage to the pipeline and creating a trench or crater
in the immediate vicinity of the rupture. If an ignition source is present, an
intense fire or explosion would result. Damage from a fire resulting from a
pipeline rupture would depend on the extent of the combustible materials in the
vicinity (infrastructure, vegetation) and local environmental conditions (e.g., rain,
snow cover, etc.). A thermal radiation intensity of approximately 4,750 Btu/hr-ft2
(15 kW/m2) will result in piloted ignition of nearby wooden structures. The
calculated distance to this isotherm from an ignited rupture is approximately
1,700 feet after 30 seconds, and quickly diminishes. This distance is roughly
equivalent to the calculated potential impact radius (PIR) of the pipeline. Thus,
wooden structures within this distance (PIR) may ignite. Structures constructed of
other materials (e.g. steel) would not be seriously affected within this distance.
Human exposure to a fire within the PIR could result in serious injury or death;
however, the probability for human injury or fatality, and property damage, is
relatively small due to the remoteness of the pipeline. The risk to people and
environmental resources decreases as distance from the rupture increases. The
pipeline will be sectionalized with MLBVs and the gas released during a rupture
scenario would be, limited to the gas volume between valves, once the valves
have fully closed. This amount of gas volumes and pressures would determine
the duration of the fire. For more information, see Table 1, Table 2, and
Attachment D - of the special permit application. The spacing between the block
valves is the subject of this special permit. Large ruptures would be detectable
through monitoring of pressure and flow conditions at pipeline facilities and the
MLBVs via the SCADA system.
b. Submit an explanation of delta/difference in safety and possible effects to the
environment between the 49 CFR Part 192 baseline (Code baseline) and usage of the
proposed special permit conditions for MLBV spacing mitigation measures.
i. The anticipated differences in effects for individual resources between the No
Action alternative and the Proposed Action alternative are discussed below.
References are made to FERC Resource Reports, where applicable, for further
detailed information and analysis of impacted resources. The basis for the FERC
Resource Reports is the Proposed Action alternative; however, the associated
environmental impact analysis is also applicable to the No Action alternative,
given both alternatives are based on below ground design and installation, and
both follow an identical route.
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1. Human Health and Safety
The impacts to human health and safety, and related infrastructure, due to the
rupture and ignition event are similar with respect to the Proposed Action and No
Action alternatives since, assuming ignition occurs, the thermal radiation released
is identical between the 20 and 50 miles spacing cases for approximately 17.5
minutes because of the identical gas flow rate from the pipeline. As stated
previously, it is within the initial period (seconds to minutes) immediately
following pipeline rupture when most injuries and fatalities occur, as this is when
the thermal radius is at its largest, but quickly dropping after the initial rupture.
With this initial period being equal in both the Proposed Action and No Action
alternatives, there are no differential safety risks.
However, the installation and operation of RCVs and ASVs in accordance with
the special permit conditions will reduce the total duration and quantity of gas
release when compared with a design in compliance with 49 CFR 192.179 or
192.620 (see Tables 5 and 6 in Attachment D - Main Line Block Valve Spacing
Technical Support).
With respect to the impacts of the total rupture event (including the timeline
beyond the initial 17.5 -minute window discussed above), the published rupture
analysis report evaluating the impact of increased sectionalizing valve spacing
further outlines that the total threshold thermal dosage (accumulated amount of
damaging heat) is equivalent in all sectionalizing valve spacing cases examined.
2. Air Quality
There will be no significant difference during construction or operation in
emissions between the No Action and Proposed Action alternatives. Most of the
heavy equipment required for construction in either alternative will be the same,
including equipment such as brushers and bulldozers for the clearing and leveling
of the ROW, trucks for transporting pipe, and side booms and welding trucks for
pipe placement and welding.
In the unlikely event of a pipeline rupture or leak, fewer MLBVs could result in
more gas outflow because the pipeline mileage between valves will be greater and
contain more gas. On the other hand, for a rupture or leak large enough to
depressurize the pipeline and trigger valve closure, as shown in the supporting
documentation and due to the special permit conditions related to use of RCVs
and ASVs, the Proposed Action alternative will result in 31% less average gas
outflow for the system per segment than the No Action alternative. This
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highlights the importance of more responsive valve functionality (RCV and ASV)
defined in the special permit conditions, which positively offsets larger pipeline
segments due to longer MLBV spacing. The lower gas outflow also results in
shorter duration of an ignited rupture and less total thermal radiation over the
entire period of the rupture event than a system designed in compliance with 49
CFR Part 192.
Should there be an operational requirement to evacuate a pipeline section, (i.e. for
maintenance reasons), there will be an incremental increase of greenhouse gas
emissions based on the Proposed Action alternative design if the gas were directly
vented, due to the increased volume between MLBVs that sectionalize the line.
However, for operational events, if the special permit is granted, AGDC will
employ several emissions reduction strategies, such as the following examples:
gas drawdown strategies, voiding the pipeline of as much gas as possible before
blowdown is initiated, and use of passive blocks (e.g. stopples) to significantly
limit the volume of gas released to atmosphere. AGDC’s commitment to utilize
these emissions reduction strategies will mitigate or eliminate any increase in
greenhouse gas or pollution emissions between the Proposed Action and No
Action alternatives.
Pipeline maintenance activities for both the No Action and Proposed Action
alternatives will require similar equipment and personnel. This comparison will
apply equally to pollutant and greenhouse emissions.
A reduced number of MLBVs for the Project Action alternative will reduce the
fugitive emissions sources of greenhouse gases.
A detailed description of air emissions, including greenhouse gas emissions, from
pipeline construction and operations are contained in FERC Resource Report 9
(Air and Noise Quality).
3. Aesthetics
There will likely be a reduced aesthetics impact with the Proposed Action
alternative as increased MLBV spacing will result in fewer valves and thus fewer
overall pipeline facilities.
4. Biological Resources (including vegetation, wetlands, and wildlife)
There will be no significant difference in impacts to vegetation, wetlands and
wildlife between the between the No Action and Proposed Action alternatives.
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Based on calculations of accumulated thermal radiation dosage (function of
thermal radiation intensity and time, see Attachment D - Main Line Block Valve
Spacing Technical Support for more detail), MLBV spacing has no effect on
piloted ignition of wooden structures for over an hour. This should correlate to
similar effects on vegetation. Both of the Alaska LNG Pipeline alternatives for the
consideration of this special permit application will be below ground and follow
the same route. Fewer valves, under the Proposed Action alternative, may result
in slightly less disturbance of or impact to biological resources on the right of
way.
FERC Resource Report 3 (Fish, Wildlife and Vegetation) contains descriptions of
vegetation and wildlife resources, and potential impacts associated with the
Alaska LNG Pipeline route. FERC Resource Report 2 contains a detailed analysis
of wetlands affected by the Alaska LNG Pipeline route and mitigation of the
impacts. The extent of impacts to biological resources will be similar or identical
under the No Action and Proposed Action alternatives.
5. Resilience and Adaptation
The potential effects of a changing climate on the Alaska LNG Pipeline design,
construction, and operation are not expected to differ between the No Action and
Proposed Action alternatives. Project design criteria incorporated consideration
of a range of variable site conditions that could occur based upon historic
information and future conditions. Mitigations are integrated into the design
where appropriate or required for facility integrity and safe operations.
Opportunities for resilience and adaptation to potential weather effects will be
considered in the design of the Alaska LNG Pipeline. For example, geothermal
modeling will be used to assess potential changes in ground temperatures that
could be caused by longer-term geothermal impacts of pipeline construction,
operations, and changes in climate. Other resilience and adaptation design
considerations for the Alaska LNG Pipeline are addressed in FERC Resource
Report No. 1.
FERC Resource Report 9 (Air and Noise Quality) discusses greenhouse gas
emissions from the pipeline.
6. Cultural Resources
There will be no difference in the effect on Cultural Resources between the No
Action and Proposed Action alternatives. Construction activities have the
potential to affect cultural resources. Ground-clearing activities under both
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alternatives will be similar. FERC is conducting the Section 106 consultation
process with stakeholders that will lead to the development of a Programmatic
Agreement to address management and recovery of known cultural resources and
any discovered during construction. The Programmatic Agreement will apply to
both the No Action and Proposed Action alternatives to mitigate effects on those
resources. FERC Resource Report 6 (Cultural Resources) addresses cultural
resources affected and associated mitigations.
7. Environmental Justice
Since both pipeline designs will be sited in the same footprint, there will be no
difference in effects on environmental justice resulting from construction or
operation of the pipeline between the No Action and Proposed Action
alternatives.
8. Geology, Soils and Mineral Resources
There will be minimal differences in the effects on geology, soils and mineral
resources between the No Action and Proposed Action alternatives. Construction
activities have the potential to affect soils in a localized manner with minimal
effect on regional geology or mineral resources. Construction activities that could
contribute to erosion include clearing and grading, excavation trenching, stockpile
management, backfilling, and the development of gravel pads. AGDC manages
erosion impacts with the use of erosion and sediment control measures, including:
a) The use of winter construction in areas of inundated and frozen ground
conditions;
b) Use of settlement basins, silt fences, and other Best Management Practices
(BMP) for storm water control;
c) Use of engineered flow diversions and slope breakers to control water
flow on slopes and around water courses; and
d) Installation of trench breakers to address storm and groundwater flow
through the trench backfill or during construction.
Construction, operations, and maintenance activities along the pipeline right-of-
way will be similar for the No Action and Proposed Action alternatives. All
excavations will be conducted as authorized under the applicable ROW
authorization. As the land management agencies responsible for lands along the
pipeline route, ROW permits will be issued by the Bureau of Land Management
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and/or the Alaska Department of Natural Resources. All excavations and other
applicable activities will be permitted through the appropriate Federal and state
agencies for both alternatives. Both alternatives will have similar impacts on soil
resources.
FERC Resource Report 7 (Soils), contains a more detailed discussion of impacts
to soils and erosion resulting from the pipeline construction and the potential
mitigation measures to address those impacts. FERC also has a standard Upland
Erosion Control, Revegetation and Maintenance Plan, to which AGDC has
proposed alternative measures that will be subject to FERC approval.
9. Indian Trust Assets
No Indian Trust Assets or Native allotments are located within the pipeline route.
10. Land Use, Subsistence, and Recreation
There will be minimal difference in the effect on land use, subsistence, and
recreation between the No Action and Proposed Action alternatives. During
construction, land use in the form of subsistence activities and recreation for both
alternatives could be altered in the immediate vicinity of the construction ROW.
The pipeline’s remote location combined with the relatively small width of the
ROW will generally limit the extent of displacement by users to the active
construction zones. Construction activities will be timed to avoid potential use
conflicts with portions of the trail used during the annual Iditarod sled-dog race.
After construction, the ROW will be graded and revegetated to a stable condition
in accordance with the FERC approved Alaska LNG Upland Erosion Control,
Revegetation and Maintenance Plan; Alaska LNG Wetland & Waterbody
Construction & Mitigation Procedures; and the associated Alaska LNG Project
Restoration Plan. No long-term linear access along the pipeline alignment is
proposed. Crossing of the ROW perpendicular to the pipeline is expected but use
of the ROW itself as any type of access road is not proposed and in fact will be
discouraged. However, under either alternative, PHMSA regulations will require
that the pipeline ROW is brushed to prevent the growth of large vegetation over
and around the pipeline to maintain a clearly defined ROW.
As shown in the supporting documentation in Attachment D - Main Line Block
Valve Spacing Technical Support, in the unlikely event of a rupture, the special
permit conditions require use of RCVs and ASVs, which will result in 31% less
average gas outflow from the system per segment than strict compliance with 49
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CFR Part 192. More responsive valve functionality (RCV and ASV) defined in
the special permit conditions will positively offset larger pipeline segments due to
longer MLBV spacing. The lower gas outflow resulting from more responsive
valve functionality will result in shorter duration of an ignited rupture and less
total thermal radiation than a system designed in full compliance with 49 CFR
Part 192.
FERC Resource Report 8 (Land Use, Recreation and Aesthetics) considers
potential effects to land use and recreation activities. FERC Resource Report 5
(Socioeconomics) considers potential impacts to subsistence.
11. Noise
During normal operations, there will be no difference in noise impacts between
the two alternatives. The difference in noise impacts during pipeline blow down
events should also be minimal.
12. Water Resources
There will be no difference in impacts to water resources between the No Action
and the Proposed Action alternatives. For both alternatives, stabilization
techniques, including gravel blankets, riprap, gabions, or geosynthetics, will be
used to stabilize the channel bed and stream banks at stream crossings.
Watercourse crossing methods for each watercourse crossing are the same for
both alternatives. Most rivers and streams along the pipeline route will be crossed
by an open-cut method during winter months. During these months, the flows of
rivers and streams are lowest, and disturbance of the channel and stream bank can
be minimized. Burial depths for crossings have been based on site specific
calculations to avoid the potential for scour.
FERC Resource Report 2 (Water Use and Quality) contains a detailed discussion
regarding the management of water during construction and operation of the
pipeline, as well as impacts to ground, surface water flow and quality resulting
from the construction and operation of the pipeline.
c. Describe safety protections provided by the proposed special permit conditions.
Several factors were taken into consideration. First, the Alaska LNG Pipeline
route has been characterized for location of dwellings and structures in
accordance with 49 CFR 192.5. Ninety-nine percent of the pipeline route is in
Class 1 location, which is defined as having 10 or fewer buildings intended for
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mile length of pipeline. Route characterization has also determined that there are
more than 700 miles of pipeline route crossing areas with no inhabited dwellings.
Table 2 – Identified Sites and Structures within the Mainline PIR adjacent to
Class 1 locations contains a list of mile posts where there are identified sites and
structures that potentially could have human occupancy within 220 yards of the
ROW. Given the geographic remoteness, robust size and grade of line pipe,
unlikelihood of internal corrosion, and monitoring conditions imposed by the
special permit, there is an extremely low probability that the pipeline will rupture.
The proposed special permit conditions, which are summarized in Section VII,
result in less time between rupture and valve actuation, improved valve
monitoring, and a resulting smaller quantity of natural gas released in the event of
failure, and require more robust pipe to be placed in proximity to key
infrastructure (e.g. key bridges identified by Alaska Department of Transportation
& Public Facilities (ADOT&PF)).
d. Explain the basis for the particular set of alternative mitigation measures used in the
proposed special permit conditions. Explain whether the measures will ensure that a
level of safety and environmental protection equivalent to compliance with existing
regulations is maintained.
The basis for the mitigation measures is the Alaska LNG Pipeline engineering
analysis, combined with consultation with PHMSA and ADOT&PF. More details on
these measures is provided in Section VIII. These measures help ensure that no
significant environmental or human safety impact will result from increasing the
MLBV spacing. The use of RCVs and ASVs allow for faster valve closure than will
be achieved with valves meeting the minimum standard for strict 49 CFR Part 192
compliance. The use of more responsive valves mitigates the longer distances
between valves proposed by the special permit.
e. Discuss how the special permit would affect the risk or consequences of a pipeline leak,
rupture or failure (positive, negative, or none). This would include how the special
permits preventative and mitigation measures (conditions) would affect the
consequences and socioeconomic impacts of a pipeline leak, rupture or failure.
As highlighted in the Project’s engineering and analysis as summarized in Attachment
D - Main Line Block Valve Spacing Technical Support document, injuries and fatalities
on gas transmission pipelines generally occur during the first 30 seconds after gas has
been released from a pipeline. 11 In the event of an Alaska LNG Pipeline failure, there
will be no difference in the volume of product released or in the likelihood of ignition
in the first 17.5 minutes. The ASVs and RCVs will decrease the total product released
and, therefore, the total thermal radiation.
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f. Discuss any effects on pipeline longevity and reliability such as life-cycle and periodic
maintenance including integrity management. Discuss any technical innovations as
well.
The Proposed Alternative will result in reduced MLBV maintenance, with no overall
impacts on pipeline longevity and reliability. Implementation of the special permit
conditions will require enhanced monitoring of RCVs, ASVs, and more stringent valve
actuation criteria than is normally required by 49 CFR Part 192.
g. Discuss how the special permit would impact human safety.
There will be no additional impact on human safety resulting from granting of the
special permit.
h. Discuss whether the special permit would affect land use planning.
The special permit will not change land use planning processes. The ROW
authorization requirements, and other land use planning notification processes will be
the same with either the No Action or Proposed Action alternative. The Proposed
Action alternative will require fewer valves along the ROW.
i. Discuss any pipeline facility, public infrastructure, safety impacts and/or environmental
impacts associated with implementing the special permit. Discuss how any
environmentally sensitive areas could be impacted.
Implementation of the special permit will reduce the number of MLBVs and associated
valve station footprints by about half. The footprint at remote MLBVs (ASVs or
RCVs) extends beyond the normal permanent ROW, affecting approximately 0.07
acres. The special permit will reduce the number of MLBVs by 22, resulting in
approximately 1.6 acres less disturbance. The special permit will require a more robust
pipeline design within proximity of key bridges resulting in a positive impact to public
infrastructure. There is no impact to environmentally sensitive areas.
V. Response to Public Comments Placed on Docket PHMSA-2017-0045
PHMSA published a Notice of Availability in the Federal Register on May 28, 2019 for four
(4) special permit requests for the line pipe of the Alaska LNG Pipeline. (84 FR 24594,
Docket Nos.: PHMSA-2017-0046, Usage of 3LPE Coating; PHMSA-2017-0044, Usage of
Strain Based Design; PHMSA-2017-0045, Alternative Mainline Block Valve Spacing; and
PHMSA-2017-0047, Usage of Crack Arrestor Spacing at www.Regulations.gov). PHMSA
requested comment on the special permit applications, the draft permit conditions, and the
draft environmental analyses. The public notice comment period ended on July 29, 2019,
with all comments received through July 29, 2019, being reviewed and considered. PHMSA
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received a public comment concerning usage of fossil fuels, the building of the Alaska LNG
Pipeline, and the building of a liquified natural gas (LNG) facility. PHMSA does not have
siting authority over pipeline facilities. The public comment received did not submit
concerns directed towards the special permit, the environmental assessment, or the special
permit conditions, which were the issues within PHMSA’s decision making authority and the
intent of the public notice.
VI. Finding of No Significant Impact
Although technically distinct, PHMSA considered the combined impacts and safety risks
associated with the issuance and implementation of the special permits, including the special
permit conditions, for usage of three-layer polyethylene (3LPE) coating, usage of strain
based design, alternative spacing of mainline block valves, and alternative spacing of crack
arrestors. PHMSA finds that special permits and associated special permit conditions will
not impose a significant impact on the human environment. The special permit conditions
are designed to be consistent with pipeline safety and to ensure the same or a greater level of
safety as will be achieved if the pipeline were designed, constructed, operated, and
maintained in full compliance with 49 CFR Part 192.
VII. Consultation and Coordination
a. Please list the name, title and company of any person involved in the preparation of
this document.
• PHMSA –Amelia Samaras (Senior Attorney), Steve Nanney (Engineer), Joshua
Johnson (Engineer)
• Alaska Gasline Development Corporation – Frank Richards (Senior Vice
President)
• Alaska LNG LLC – Rick Noecker (PHMSA Filing Coordinator), Mario Macia
(Pipeline Technology Lead), Norm Scott (ERL Advisor)
• Michael Baker International – Keith Meyer (Senior Pipeline Advisor), Paul
Carson (Corporate Pipeline Engineer)
b. Please provide names and contact information for any person or entity you know will
be impacted by the special permit. PHMSA may perform appropriate public scoping.
The applicant’s assistance in identifying these parties will speed the process
considerably.
Adjacent landowners/land managers potentially impacted:
Cook Inlet Region, Inc.
Jason Brune
Sr. Director, Land and Resources
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PO Box 93330
Anchorage, AK 99509
(907) 263-5104
Bureau of Land Management
Earle Williams
Chief, Branch of realty and Conveyance Services
BLM Alaska State Office 222
West 7th Avenue #13
Anchorage, AK 99513-7504
(907) 271-5762
Alaska Department of Natural Resources
Tom Stokes
State Pipeline Coordinator
3651 Penland Parkway
Anchorage, AK 99508
(907) 269-6419
Alaska Department of Transportation & Public Facilities
Joe Kemp
Gasline Liaison
2301 Peger Road
Fairbanks, AK 99709
(907) 451-5497
Brooke Merrell
Transportation Planner
United States National Park Service, Alaska Regional Office
240 W 5th Ave
Anchorage, AK 99501
(907) 644-3397
Don Striker
Superintendent
Denali National Park and Preserve
PO Box 9
Denali Park, AK 99755-0009
(907) 683-9532
c. If you have engaged in any stakeholder or public communication regarding this
request, please include information regarding this contact.
Alaska LNG has been active in stakeholder engagement throughout Alaska. As
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Alaska LNG Pipeline held one-on-one as well as multiagency engagement
meetings to cover pipeline design construction and routing. Additionally, there
have been over 20 engagement meetings between Alaska LNG and PHMSA. The
MLBV spacing special permit was a topic of discussion at multiple meetings.
Additionally, an overview of this special permit was provided at a joint meeting
with PHMSA and FERC on April 19, 2016.
PHMSA has participated in scoping and public outreach lead by FERC related to
the Alaska LNG Pipeline FERC Resource Reports. Details of the public outreach,
which included both members of tribal entities and the general public, are
provided in Sections 1.9 and Appendix D of the FERC Resource Report 1.
VIII. Bibliography
Alaska LNG Project. 2017a. FERC Resource Report No. 1 (General Project Description)10
Alaska LNG Project. 2017b. FERC Resource Report No. 2 (Water Use and Quality)
Alaska LNG Project. 2017c. FERC Resource Report No. 3 (Fish, Wildlife, and Vegetation)
Alaska LNG Project. 2017d. FERC Resource Report No. 4 (Cultural Resources)
Alaska LNG Project. 2017e. FERC Resource Report No. 5 (Socioeconomics)
Alaska LNG Project. 2017f. FERC Resource Report No. 6 (Geological Resources)
Alaska LNG Project. 2017g. FERC Resource Report No. 7 (Soils)
Alaska LNG Project. 2017h. FERC Resource Report No. 8 (Land Use, Recreation, and Aesthetics)
Alaska LNG Project. 2017i. FERC Resource Report No. 9 (Air and Noise Quality)
Alaska LNG Project. 2017j. FERC Resource Report No. 10 (Alternatives)
Alaska LNG Project. 2017k. FERC Resource Report No. 11 (Reliability and Safety)
Eiber, R., and Kiefner, J. 2010. Review of Safety Considerations for Natural Gas Pipeline Block
Valve Spacing. ASME Standards Technology, LLC. Columbus. July.
IX. Conditions: Example of what special permit (SP) conditions address
10 Alaska LNG Project FERC Resource Reports are available for review at: https://alaska-lng.com/regulatory-
process/ferc-application-exhibits/resource-reports/.
Page 33 of 40

<<<PAGE 34>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
a) Spacing will only be increased beyond 49 CFR Part 192 limits in Class 1 locations. The
maximum spacing north of Fairbanks will be 50 miles, while the maximum spacing south
of Fairbanks will be 30 miles.
b) MLBVs will be placed as close as reasonably possible to the start and end mileposts in
Class 2, 3 and 4 locations and will not exceed the spacing requirements of 49 CFR
192.179(a).
c) An engineering analysis must be performed to confirm that the number and location of
MLBVs proposed in the special permit account for the criteria in Section 846.1.1 of
ASME B31.8.
d) Enhanced valve closure criteria that will initiate valve closure when either of the
following conditions occurs:
o Pressure drops to 75% of the operating pressure at the sectionalizing mainline
valve based upon maximum flow model gradients for the upstream compressor
station discharge at MOP (2050 psig). In addition, ASV set points shall not be less
than that required to actuate the valve before a downstream RCV actuates.
o Decrease in operating pressure in fifteen (15) minutes is greater than 10%.
e) Real time monitoring at the Pipeline Control Center of MLBVs located at compressor,
heater and metering stations (RCVs).
f) In high consequence areas (49 CFR 192.905) in Class 1 and 2 locations, sectionalizing
block valve spacing must comply with the requirements of 49 CFR 192.179(a).
g) Emergency closure drills simulating shutting down of a randomly selected section of
transmission line will be performed at least once in a calendar year, but within an interval
not to exceed 15 months. The operator may conduct a table-top emergency closure drill
to meet this requirement for no more than two out of each three calendar years. The
operator will conduct a site-specific emergency closure drill at a field site at least once in
every three calendar years.
h) Pipeline control room operators will immediately and directly notify the 911 emergency
call center(s) for the affected communities and jurisdictions, when a rupture is indicated.
i) Valve position and operational status of all RCVs affected by a leak/rupture event until
positive isolation of the effected segment is confirmed will be continually monitored by
pipeline control center operators.
j) An emergency response plan will be developed:
Page 34 of 40

<<<PAGE 35>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
o identifying the appropriate public safety access point (911 emergency call center),
fire, police, and other public officials to be notified;
o identifying responsibility, resources, jurisdictional area, and emergency contact
telephone numbers for both local and out-of-area calls of each government
organization that may respond to a pipeline emergency; and
o establishing protocols for informing the officials about the operator's ability to
respond to the pipeline emergency and means of communication.
k) Detailed maintenance procedures will be developed for all MLBV and operators installed
on the Mainline. These procedures will follow manufacturer recommendations and
industry practice.
l) Detailed maintenance procedures will be developed for all pressure sensing equipment
installed with the MLBV. These procedures will follow manufacturer recommendations
and industry practice.
m) A training program will be implemented for appropriate operating personnel to ensure
they have a thorough knowledge of, and are qualified to implement, the emergency
response plan procedures.
Page 35 of 40

<<<PAGE 36>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Table 3 – Identified Sites and Structures within the Mainline PIR adjacent to Class 1 Locations
[See MLBV Locations in Table 1]
Milepost
Offset
Distance
(feet)
Direction Class
Location Feature Comment
80.66 693 Left 1 Structure
174.78 363 Left 1 Structure DOT/PF Garage
174.85 288 Left 1 Structure
174.86 296 Left 1 Structure
174.86 335 Left 1 Structure
174.87 542 Left 1 Structure
174.90 452 Left 1 Structure
175.12 571 Left 1 Structure
236.12 1450 Left 1 Structure
236.12 494 Left 1 Structure
236.12 542 Left 1 Structure
236.12 547 Left 1 Structure
236.68 867 Left 1 Identified Site Marion Creek Campground
241.06 1364 Right 1 Structure
310.41 760 Right 1 Structure
310.42 821 Right 1 Structure
352.79 603 Left 1 Associated Structure to Identified Site Hotspot Cafe
352.80 638 Left 1 Identified Site Hotspot Cafe
358.41 619 Right 1 Structure
438.83 215 Left 1 Structure
438.96 1324 Left 1 Structure
438.98 966 Left 1 Structure
439.14 938 Left 1 Structure
439.20 514 Left 1 Structure
439.20 872 Left 1 Structure
439.21 1191 Left 1 Structure
439.26 607 Left 1 Structure
439.27 1203 Left 1 Structure
439.31 971 Left 1 Structure
469.64 589 Left 1 Structure
469.69 983 Left 1 Structure
469.70 1014 Left 1 Structure
469.70 927 Left 1 Structure
470.69 1194 Right 1 Structure
470.69 833 Right 1 Structure
470.69 750 Right 1 Structure
470.71 302 Right 1 Structure
470.71 412 Right 1 Structure
471.40 1025 Right 1 Structure
471.42 701 Right 1 Structure
471.86 75 Left 1 Structure
471.95 352 Right 1 Structure
Page 36 of 40

<<<PAGE 37>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Table 3 – Identified Sites and Structures within the Mainline PIR adjacent to Class 1 Locations
[See MLBV Locations in Table 1]
Milepost
Offset
Distance
(feet)
Direction Class
Location Feature Comment
471.96 252 Left 1 Structure
471.97 662 Right 1 Structure
471.97 418 Left 1 Structure
471.97 399 Right 1 Structure
471.97 208 Left 1 Structure
471.98 242 Left 1 Structure
472.04 535 Right 1 Structure
472.28 754 Right 1 Structure
472.33 564 Right 1 Structure
472.34 651 Right 1 Structure
472.35 577 Right 1 Structure
472.37 597 Right 1 Structure
472.38 710 Right 1 Structure
497.83 1396 Right 1 Structure
497.84 1210 Right 1 Structure
497.88 1447 Right 1 Structure
498.76 1157 Right 1 Structure
501.37 941 Right 1 Structure
502.73 1385 Right 1 Structure
504.24 1396 Right 1 Structure
504.87 269 Left 1 Structure
505.03 1379 Left 1 Structure
506.03 1338 Right 1 Structure
511.07 1191 Right 1 Structure
511.86 758 Right 1 Structure
511.86 939 Right 1 Structure
512.89 1057 Right 1 Structure
513.05 760 Left 1 Structure
513.06 1065 Left 1 Structure
513.06 307 Left 1 Structure
513.09 366 Left 1 Structure
513.09 963 Left 1 Structure
513.09 857 Left 1 Structure
513.10 1311 Left 1 Structure
513.16 1161 Left 1 Structure
513.17 682 Left 1 Structure
513.23 1071 Left 1 Structure
514.79 1039 Left 1 Structure
514.82 1232 Left 1 Structure
523.45 585 Right 1 Structure
526.82 359 Left 1 Structure
529.54 497 Right 1 Structure
529.80 934 Left 1 Identified Site Denali RV Park and Motel
536.66 1457 Right 1 Structure Denali Salmon Bake Cabins ‐ Single cabin
536.66 1465 Right 1 Structure Denali Salmon Bake Cabins ‐ Single cabin
536.66 1420 Right 1 Structure Denali Salmon Bake Cabins ‐ Single cabin
Page 37 of 40

<<<PAGE 38>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Table 3 – Identified Sites and Structures within the Mainline PIR adjacent to Class 1 Locations
[See MLBV Locations in Table 1]
Milepost
Offset
Distance
(feet)
Direction Class
Location Feature Comment
536.66 1345 Right 1 Structure Denali Salmon Bake Cabins ‐ Single cabin
536.66 1346 Right 1 Structure Denali Salmon Bake Cabins ‐ Single cabin
536.66 1409 Right 1 Structure Denali Salmon Bake Cabins ‐ Single cabin
536.68 1409 Right 1 Identified Site Alpine Glow Restaurant
536.70 1016 Right 1 Structure
536.71 1349 Right 1 Structure Denali Bluffs Hotel ‐ Single cabin
536.71 1359 Right 1 Structure Denali Bluffs Hotel ‐ Single cabin
536.72 1266 Right 1 Structure Denali Bluffs Hotel ‐ Single cabin
536.72 1378 Right 1 Structure Denali Bluffs Hotel ‐ Single cabin
536.72 1288 Right 1 Structure Denali Bluffs Hotel ‐ Single cabin
536.73 1393 Right 1 Structure Denali Bluffs Hotel ‐ Single cabin
536.73 1313 Right 1 Structure Denali Bluffs Hotel ‐ Single cabin
536.73 1401 Right 1 Structure Denali Bluffs Hotel ‐ Single cabin
536.74 1422 Right 1 Structure Denali Bluffs Hotel ‐ Single cabin
536.75 1437 Right 1 Structure Denali Bluffs Hotel ‐ Single cabin
536.81 1099 Right 1 Identified Site Grand Denali Lodge
536.81 993 Right 1 Associated Structure to Identified Site Grand Denali Lodge
536.85 1171 Right 1 Associated Structure to Identified Site Grand Denali Lodge
537.10 1437 Right 1 Structure
537.31 1344 Right 1 Associated Structure to Identified Site ERA Helicopters
537.32 1312 Right 1 Identified Site ERA Helicopters
551.32 1224 Right 1 Structure
551.34 1457 Right 1 Structure
551.39 1203 Right 1 Structure
551.43 1357 Right 1 Structure
551.65 1376 Right 1 Identified Site McKinley Creekside Cabins
551.65 1442 Right 1 Associated Structure to Identified Site McKinley Creekside Cabins
551.65 1258 Right 1 Associated Structure to Identified Site McKinley Creekside Cabins
551.65 1435 Right 1 Associated Structure to Identified Site McKinley Creekside Cabins
551.65 957 Right 1 Associated Structure to Identified Site McKinley Creekside Cabins
551.66 1404 Right 1 Associated Structure to Identified Site Denali Perch Resort
551.66 1430 Right 1 Associated Structure to Identified Site Denali Perch Resort
551.66 1459 Right 1 Associated Structure to Identified Site Denali Perch Resort
551.86 1335 Right 1 Associated Structure to Identified Site Denali Perch Resort
551.87 1025 Right 1 Associated Structure to Identified Site Denali Perch Resort
556.31 542 Right 1 Structure
556.46 587 Right 1 Structure
556.48 332 Right 1 Structure
556.51 177 Right 1 Structure
559.85 1380 Left 1 Structure Power Plant
560.07 554 Right 1 Structure Denali Fly Fishing Guides
560.15 845 Left 1 Structure
564.83 809 Right 1 Structure
566.33 1417 Right 1 Identified Site Local Gov't building
566.35 607 Right 1 Identified Site DOT/PF Cantwell Station
Page 38 of 40

<<<PAGE 39>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Table 3 – Identified Sites and Structures within the Mainline PIR adjacent to Class 1 Locations
[See MLBV Locations in Table 1]
Milepost
Offset
Distance
(feet)
Direction Class
Location Feature Comment
566.48 651 Right 1 Structure
566.50 511 Left 1 Structure
566.51 473 Right 1 Structure
566.69 394 Right 1 Structure
566.69 604 Right 1 Structure
566.74 654 Right 1 Structure
566.79 1043 Right 1 Structure
566.79 1361 Right 1 Structure
566.79 1017 Right 1 Structure
588.74 660 Right 1 Structure
588.74 810 Right 1 Structure
588.75 755 Right 1 Structure
588.77 910 Right 1 Structure
588.78 337 Right 1 Structure
608.38 1389 Left 1 Structure
608.39 1371 Left 1 Structure
608.39 1435 Left 1 Structure
608.45 1357 Left 1 Structure
608.64 345 Left 1 Structure
608.67 212 Right 1 Structure
608.69 126 Left 1 Structure
615.43 886 Left 1 Structure
615.44 956 Left 1 Structure
630.42 1125 Left 1 Identified Site Byers Lake Campground (73 units)
634.11 1449 Right 1 Identified Site Trapper Creek Pizza Pub
634.13 1430 Right 1 Associated Structure to Identified Site Trapper Creek Pizza Pub
634.14 729 Right 1 Structure
634.17 523 Right 1 Structure
636.20 1244 Left 1 Structure
650.39 1132 Right 1 Structure
650.41 1379 Left 1 Structure
657.69 982 Left 1 Structure
658.27 533 Left 1 Structure
662.53 1388 Left 1 Structure
664.35 1282 Left 1 Structure
664.66 1345 Left 1 Structure
664.67 1008 Left 1 Structure
664.68 581 Left 1 Structure
664.74 1016 Right 1 Structure
664.78 385 Right 1 Structure
664.83 979 Right 1 Structure
665.03 476 Right 1 Structure
665.62 981 Left 1 Structure
665.70 1432 Left 1 Structure
665.70 1318 Left 1 Structure
665.70 1239 Left 1 Structure
Page 39 of 40

<<<PAGE 40>>>

ALASKA LNG PIPELINE
MLBV SPACING
SPECIAL PERMIT: ATTACHMENT C
DATE: AUGUST 1, 2019
Table 3 – Identified Sites and Structures within the Mainline PIR adjacent to Class 1 Locations
[See MLBV Locations in Table 1]
Milepost
Offset
Distance
(feet)
Direction Class
Location Feature Comment
665.70 767 Left 1 Structure
665.70 1055 Left 1 Structure
665.71 1446 Left 1 Structure
665.71 726 Left 1 Structure
665.81 1342 Left 1 Structure
665.88 1062 Left 1 Structure
727.78 171 Right 1 Structure
764.53 1206 Right 1 Structure
764.54 1313 Right 1 Structure
764.62 870 Left 1 Structure
764.76 935 Left 1 Structure
764.91 1412 Left 1 Structure
764.92 1245 Left 1 Structure
764.94 648 Left 1 Structure
765.03 712 Left 1 Structure
797.12 1254 Left 1 Structure
797.13 487 Left 1 Structure
797.14 1092 Left 1 Structure
797.20 204 Right 1 Structure
797.57 812 Left 1 Structure
798.30 1246 Right 1 Associated Structure to Identified Site Nikiski Ship Repair
798.33 1279 Right 1 Associated Structure to Identified Site Nikiski Ship Repair
798.34 1150 Right 1 Identified Site Nikiski Ship Repair
798.54 1447 Left 1 Identified Site Commercial Building
801.27 767 Left 1 Structure
801.31 1352 Left 1 Structure
803.58 966 Left 1 Structure
803.60 1038 Left 1 Structure
803.62 1135 Left 1 Structure
806.32 1030 Right 1 Structure Tesoro Kenai Refinery
806.32 895 Right 1 Structure Tesoro Kenai Refinery
806.32 1120 Right 1 Structure Tesoro Kenai Refinery
806.32 1075 Right 1 Structure Tesoro Kenai Refinery
806.32 662 Right 1 Structure Tesoro Kenai Refinery
806.32 617 Right 1 Structure Tesoro Kenai Refinery
806.33 1444 Left 1 Structure
Completed by PHMSA in Washington, DC on: September 9, 2019
Page 40 of 40

## Provenance

- Official: Yes
- Source: <https://www.regulations.gov/docket/PHMSA-2017-0045>
- Source ID: `phmsa-special-permits`
- SHA-256: `56b42a4793f200bb1fabef0df869385cd1a804271d9c0294cc906ab5d802cfe8`
- Retrieved: 2026-08-20T01:06:17.853Z
- Exported: 2026-08-25T03:24:59.664Z
- Document slug: `phmsa-special-permit-phmsa-2017-0045`

### Source metadata

```json
{
  "materialSubtype": "pipeline_special_permit",
  "operator": "Alaska Gas Development Corporation – AGDC",
  "system": "Gas Transmission",
  "issuedOn": "2019-09-09",
  "issuanceStatus": "issued",
  "renewal": null,
  "indexUrl": "https://www.phmsa.dot.gov/pipeline/special-permits-state-waivers/special-permits-issued",
  "docketUrl": "https://www.regulations.gov/docket/PHMSA-2017-0045",
  "docketDocumentCount": 4,
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  "decisions": [
    {
      "id": "PHMSA-2017-0045-0009-0900006484a19d52",
      "regulationsGovDocumentId": "PHMSA-2017-0045-0009",
      "title": "2017-0045 AGDC MLBV Spacing LOD",
      "postedDate": "2021-02-03",
      "documentUrl": "https://www.regulations.gov/document/PHMSA-2017-0045-0009",
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}
```
