# U.S. DOT/PHMSA - Regulatory Impact Analysis

**Citation:** 090000648242be17  
**Type / status:** rulemaking / current  
**Agency:** Pipeline and Hazardous Materials Safety Administration  
**Effective:** Not stated  
**Published:** Not stated

Pipeline and Hazardous Materials Safety Administration U.S. Department of Transportation Regulatory Impact Analysis Underground Natural Gas Storage Interim Final Rule December 7, 2016 Regulatory Impact Analysis: Underground Natural Gas Storage Executive Summary Federal government data show a total of 390 active underground natural gas storage fields in the United States as of 2015 (EIA, 2016e). The fields encompass an estimated 16,991 injection/withdrawal or pressure control/observation wells (AGA,...

## Document text

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Pipeline and Hazardous Materials Safety Administration
U.S. Department of Transportation
Regulatory Impact Analysis
Underground Natural Gas Storage
Interim Final Rule
December 7, 2016

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Regulatory Impact Analysis: Underground Natural Gas Storage Front Matter
Prepared with support by
Abt Associates Inc.
55 Wheeler Street, Cambridge, MA 02138
under Delivery Order #DTPH5616F00006
ii

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Regulatory Impact Analysis: Underground Natural Gas Storage Table of Contents
Table of Contents
Executive Summary ................................................................................................................ 1
1 Introduction .................................................................................................................... 1-1
1.1 Purpose ................................................................................................................................ 1-1
1.2 Need for Action ................................................................................................................... 1-1
1.3 Report Organization ............................................................................................................ 1-2
2 Overview of the Natural Gas Storage Industry .......................................................... 2-1
2.1 Storage Fields ...................................................................................................................... 2-1
2.2 Number of Wells ................................................................................................................. 2-2
2.3 Operators ............................................................................................................................. 2-4
2.4 Regulation of Underground Natural Gas Storage Facilities ................................................ 2-5
3 Summary of IFR Requirements ................................................................................... 3-1
3.1 API Recommended Practices .............................................................................................. 3-1
3.2 Regulatory Alternatives Considered by PHMSA ................................................................ 3-3
4 Analysis Framework ...................................................................................................... 4-1
4.1 Analysis Baseline ................................................................................................................ 4-1
4.1.1 Federal and State Regulations ................................................................................. 4-1
4.1.2 Existing Industry Practices and Implementation ..................................................... 4-1
4.1.3 Baseline Scenarios ................................................................................................... 4-4
4.2 Other Analysis Elements ..................................................................................................... 4-4
4.2.1 Timeframe for the Analysis ..................................................................................... 4-5
4.2.2 Regulatory Alternatives ........................................................................................... 4-5
4.2.3 Discounting of Future Costs and Benefits ............................................................... 4-5
4.2.4 Industry Growth Rate .............................................................................................. 4-5
5 Costs ................................................................................................................................ 5-1
5.1 Costing Methodology .......................................................................................................... 5-1
5.1.1 Mechanical Integrity Testing Costs ......................................................................... 5-1
5.1.2 Costs of Addressing Integrity Issues Identified through Testing ............................. 5-2
5.1.3 Costs of Other RP Elements .................................................................................... 5-3
5.1.4 Reporting Costs ....................................................................................................... 5-4
5.2 Industry Compliance Costs ................................................................................................. 5-5
5.2.1 Full Industry Compliance Baseline.......................................................................... 5-5
5.2.2 Partial Industry Compliance Baseline ...................................................................... 5-5
5.2.3 Regulatory Compliance Only Baseline .................................................................... 5-8
5.3 Economic Impacts ............................................................................................................. 5-10
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Regulatory Impact Analysis: Underground Natural Gas Storage Table of Contents
6 Benefits ............................................................................................................................ 6-1
6.1 Natural Gas Releases from Underground Storage .............................................................. 6-1
6.1.1 Catastrophic Releases .............................................................................................. 6-1
6.1.2 Operational Releases ............................................................................................... 6-3
6.2 Benefits of the IFR .............................................................................................................. 6-3
7 Uncertainty and Limitations ......................................................................................... 7-1
7.1 Affected Facilities and Operators ........................................................................................ 7-1
7.2 Baseline Degree of Compliance .......................................................................................... 7-2
7.3 Mechanical Integrity Testing Costs .................................................................................... 7-2
7.4 Timing of Compliance Activities ........................................................................................ 7-3
7.5 Effectiveness of RPs to Prevent Future Incidents ............................................................... 7-3
8 Analyses Required under Applicable Statutes or Executive Orders ........................ 8-1
8.1 Executive Orders 12866 and 13563: Analysis of Costs and Benefits ................................. 8-1
8.2 Regulatory Flexibility Act (RFA) ....................................................................................... 8-2
8.2.1 Identifying Small Entities ........................................................................................ 8-2
8.2.2 Small Businesses Affected by the Final Rule .......................................................... 8-3
8.2.3 Impacts of the IFR on Small Entities ....................................................................... 8-4
8.3 Unfunded Mandates Reform Act (UMRA) Analysis .......................................................... 8-5
8.4 Executive Order 13132: Federalism .................................................................................... 8-5
8.5 Executive Order 13211: Actions Concerning Regulations That Significantly Affect
Energy Supply, Distribution, or Use ................................................................................... 8-6
8.6 Paperwork Reduction Act of 1995 ...................................................................................... 8-7
9 References ....................................................................................................................... 9-1
Appendix A – Summary of API Recommended Practices .................................................. 1
Appendix B – Operator-level Costs ....................................................................................... 1
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Regulatory Impact Analysis: Underground Natural Gas Storage List of Exhibits
List of Exhibits
Exhibit 2-1: Underground Natural Gas Storage by State in 2015. ............................................................. 2-2
Exhibit 2-2: Top 10 Underground Natural Gas Storage Facility Operators by Working Capacity in
2015; in Alphabetical Order. ............................................................................................... 2-4
Exhibit 2-3: Summary of State Mechanical Integrity Requirements for Natural Gas Storage .................. 2-6
Exhibit 4-1: Operators with Existing Commitments to Conducting Integrity Testing .............................. 4-4
Exhibit 5-1: Well Testing Costs by Depth Category (CD). ........................................................................ 5-1
Exhibit 5-2: Recordkeeping and Reporting Costs (2015$) ........................................................................ 5-5
Exhibit 5-3: Annualized Compliance Costs Relative to the Full Industry Compliance Baseline
Scenario (2015$) ................................................................................................................. 5-5
Exhibit 5-4: Incremental Integrity Testing Costs Relative to the Partial Industry Compliance
Baseline Scenario, by State. ................................................................................................ 5-6
Exhibit 5-5: Annualized Integrity Testing Costs Relative to the Partial Industry Compliance
Baseline Scenario (Million 2015$)1
.................................................................................... 5-7
Exhibit 5-6: Annualized Compliance Costs Relative to the Partial Industry Compliance Baseline
Scenario (Million 2015$)1
................................................................................................... 5-7
Exhibit 5-7: Incremental Integrity Testing Costs Relative to the Regulatory Compliance Only
Baseline Scenario, by State. ................................................................................................ 5-8
Exhibit 5-8: Annualized Integrity Testing Costs Relative to the Regulatory Compliance Only
Baseline Scenario (Million 2015$)1
.................................................................................... 5-9
Exhibit 5-9: Annualized Compliance Costs Relative to the Regulatory Compliance Only Baseline
Scenario (Million 2015$)1
................................................................................................. 5-10
Exhibit 6-1: Social Cost of Methane1,2
....................................................................................................... 6-5
Exhibit 6-2: Climate Change-related Impacts of Methane Emissions from Natural Gas Storage
Wells ................................................................................................................................... 6-5
Exhibit 8-1: Small Business Size Standards: Subsector 486 – Pipeline Transportation ............................ 8-3
Exhibit 8-2: Size of Natural Gas Underground Storage Operating Entities Affected by the IFR ............. 8-4
Exhibit 8-3: Summary of Economic Impact Screening Analysis .............................................................. 8-5
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Regulatory Impact Analysis: Underground Natural Gas Storage Executive Summary
Executive Summary
The Pipeline and Hazardous Materials Safety Administration (PHMSA) is promulgating an interim
final rule (IFR) that revises the Pipeline Safety Regulations applicable to underground natural gas
storage facilities. The IFR incorporates by reference American Petroleum Institute (API)
Recommended Practices (RP): API RP 1170, “Design and Operation of Solution-mined Salt Caverns
used for Natural Gas Storage” (July 2015), and API RP 1171, “Functional Integrity of Natural Gas
Storage in Depleted Hydrocarbon Reservoirs and Aquifer Reservoirs” (September 2015).
The RPs provide consensus safety measures for design, construction, maintenance, risk-management,
and integrity-management procedures for natural gas storage. By adopting the API RPs by
references, the IFR takes an urgent first step to establishing uniform safety standards across the
United States and addressing the Congressional mandate contained in the PIPES Act of 2016 for
PHMSA to promulgate minimum safety standards for underground natural gas storage facilities.
Natural gas storage facility operators and industry trade groups have highlighted their existing
commitment to implementing the API RPs. While intrastate storage facilities in certain states with
existing regulations are currently required to implement certain safety measures such as
assessing the integrity of their wells, for other facilities compliance with the API RPs is currently
voluntary.
1 The IFR will set regulatory requirements for operators to assess the operational safety of
their underground natural gas storage facilities and document the implementation of identified safety
solutions. To the extent that some operators may not have implemented the practices contained in the
API RPs in the absence of regulation, the IFR would impose incremental costs on the industry. Based
on a review of existing practices, PHMSA estimates that incremental costs will mostly result from
the requirement to test the mechanical integrity of natural gas storage wells and to submit
documentation to PHMSA.
This report details PHMSA’s analysis of the costs and benefits of the IFR. This regulatory analysis
meets PHMSA’s statutory requirement for risk analysis for new rules as required by 49 USC 60102.
It also provides information to support the review of the costs and benefits of the regulation in
accordance with Executive Orders 12866 and 13563.2
1 On February 5, 2016, PHMSA issued Advisory Bulletin ADB–2016–02 (81 FR 6334). The advisory bulletin recommended that
operators of underground natural gas storage facilities review their operating, maintenance, and emergency response activities to
ensure that the integrity of underground natural gas storage facilities is properly maintained. This bulletin informed operators
about recommended practices and urged operators to take all necessary actions to prevent and mitigate breach of integrity, leaks,
or failures at their underground natural gas storage facilities and to ensure the safety of the public and operating personnel and to
protect the environment.
2 Executive Order 13563 (Improving Regulation and Regulatory Review; January 18, 2011), reaffirms the principles enunciated
in Executive Order 12866 (Regulatory Planning and Review; September 30, 1993) by stating that “to the extent permitted by law,
each agency must, among other things: (1) propose or adopt a regulation only upon a reasoned determination that its benefits
justify its costs (recognizing that some benefits and costs are difficult to quantify); (2) tailor its regulations to impose the least
burden on society, consistent with obtaining regulatory objectives, taking into account, among other things, and to the extent
practicable, the costs of cumulative regulations; (3) select, in choosing among alternative regulatory approaches, those
approaches that maximize net benefits (including potential economic, environmental, public health and safety, and other
advantages; distributive impacts; and equity); (4) to the extent feasible, specify performance objectives, rather than specifying the
behavior or manner of compliance that regulated entities must adopt; and (5) identify and assess available alternatives to direct
regulation, including providing economic incentives to encourage the desired behavior, such as user fees or marketable permits,
or providing information upon which choices can be made by the public.
ES-1

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Regulatory Impact Analysis: Underground Natural Gas Storage Executive Summary
Federal government data show a total of 390 active underground natural gas storage fields in the
United States as of 2015 (EIA, 2016e). The fields encompass an estimated 16,991
injection/withdrawal or pressure control/observation wells (AGA, 2014). Approximately 60 percent
of the aggregate storage capacity is associated with the interstate transportation of natural gas (FERC,
2016), with the remaining 40 percent involved in intrastate transportation.3
This regulatory analysis considers impacts relative to a baseline that includes the practices currently
implemented by operators to comply with state regulations where applicable, operator integrity
management programs, and industry commitments, including by Interstate Natural Gas Association
of America (INGAA) members to implement API RP 1170 and 1171 within the next decade
(INGAA, 2016). INGAA members operate approximately half of active natural gas storage fields
(210 fields out of the total 390 fields) and 70 percent of wells.
Exhibit ES-1 summarizes the estimated annualized costs of the IFR relative to three baseline
scenarios that reflect the assumed level of implementation of the API RPs in the absence of a federal
regulation. The first scenario is full compliance in the baseline (full compliance); the second scenario
is baseline compliance by operators of facilities covered by state regulations or that have made
commitments to implement the RPs individually or through their trade association (partial
compliance); the third scenario is only wells in intrastate facilities subject to state regulations would
be tested in the baseline (regulatory compliance only). The cost impacts of the IFR range from
increased reporting burden only for the full compliance baseline to the costs of conducting
mechanical integrity tests on zero, 2,408 and 13,862 active wells, respectively, for the full
compliance, partial compliance, and regulatory compliance only baselines. These estimates reflect
PHMSA’s assumptions regarding the timing of mechanical integrity tests over a 10-year phase-in
period and 10-year interval between tests. Section 5 of this report details the analysis.
As described in Section 5, the analysis focuses specifically on costs to comply with the requirements
to conduct mechanical integrity tests. This focus is reasonable given the potential significance and
magnitude of costs to underground natural gas storage facility operators, but it is important to note
that operators must also comply with all other applicable measures described in the API RPs. For this
analysis, PHMSA determined that the costs for these other measures will be small because operators
already implement the measures in the baseline or compliance will require only de minimis changes
in existing practices.
PHMSA seeks comment and data on which of these baseline scenarios best characterizes the current
compliance in the industry.
3 The 192 interstate fields account for the 60 percent of working gas capacity (2,884 billion cubic feet) and 65 percent of the
wells (11,065 wells), whereas 198 intrastate fields account for 40 percent of the working gas capacity (1,872 billion cubic feet)
and 35 percent of the wells (5,926 wells).
ES-2

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Regulatory Impact Analysis: Underground Natural Gas Storage
Executive Summary
Exhibit ES-1: Incremental Annualized Costs of the FR (Million 20155)'
Full Compliance
Incremental Costs Relative to API RPs Implementation Baseline
Baseline
Partial Compliance
Regulatory Compliance
Cost Component
3%
7%
3%
Baseline
7%
3%
Only Baseline
Discount
7%
Rate
Discount
Rate
Discount Discount
Rate
Rate
Discount
Rate
Discount
Rate
Mechanical integrity testing?
$0.0
$0.0
$27.2
$31.7
$170.6
$193.6
Other RP elements
$0.0
$0.0
$0.0
$0.0
$0.0
$0.0
Reporting
<$0.1
<$0.1
<$0.1
<$0.1
<$0.1
<$0.1
TOTAL'
<$0.1
<$0.1
$27.2
$31.7
$170.6
TRange reflects the assumed baseline level of compliance with API RPs in absence of regulatory requirements.
$193.6
2 Based on 10-year phase-in of integrity tests and a 10-year interval between tests. See Section 4 for details.
Based on information provided by the industry, PHMSA assesses the most likely baseline conditions
as lying between full compliance and partial compliance. This means that the estimated annual costs
of the rule range from $0.1 million (under the full compliance baseline) to $27.2 million (under the
partial compliance baseline) using a 3 percent discount rate. Estimated annual costs are $0.1 million
(under the full compliance baseline) to $31.7 million (under the partial compliance baseline) using a
7 percent discount rate. PHMSA judges the regulatory compliance only baseline as highly unlikely
given information provided by the major trade association representing underground natural gas
storage facility operators regarding baseline implementation of API RPs. Accordingly, the estimated
costs under that scenario represent a less likely outcome from an incremental cost perspective. As
such, PHMSA determined that the final rule is not economically significant under Executive Orders
12866 and 13563 because the estimated annual impact is less than $100 million.
The FR rule will provide benefits by setting uniform and enforceable PHMSA minimum safety
standards for all natural gas storage facilities across the United States. The standards are designed to
enable natural gas storage facility operators to detect and address well integrity issues and thereby
prevent accidental releases of natural gas and the resulting damages and environmental impacts.
PHMSA does not have data to quantify the change in risk due to required integrity tests and other
measures provided by the API RPs, and the resulting benefits. As noted in Section 6 of this report,
however, past accidents involving natural gas storage facilities have resulted in significant damages,
evacuations, injuries, fatalities, and environmental impacts. Sempra Energy, the parent company of
Southern California Gas Company (SoCalGas) which operates the Aliso Canyon facility, has
estimated the private financial costs of the Aliso Canyon incident at $763 million (Sempra Energy,
2016).4, 5 These costs do not include additional costs to society resulting from the release, such as
4 Of the $763 million, Sempra Energy notes "approximately 70% is for the temporary relocation program (including cleaning
costs and certain labor costs) and approximately 20% is for efforts to control the well, stop the leak, stop or reduce emissions, and
value of lost gas, the costs to mitigate the actual natural gas released and other costs. Cost estimate excludes any potential
the estimated cost of the root cause investigation. The remaining amount includes legal costs incurred to defend litigation, the
damage awards, restitution and any civil, administrative or criminal fines and other penalties that may be imposed, as well as any
estimate what amounts, if any, will be incurred for such matter." (Sempra Energy, 2016)
additional costs to clean homes and future legal costs necessary to defend litigation, among other potential costs, as we cannot
5 Private financial costs include a mix of remediation, repair, ex gratia payments to persons and public agencies affected by the
incident, anticipated or actual penalties, as well as litigation costs and settlements. Firms vary in the extent of their public
ES-3

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Regulatory Impact Analysis: Underground Natural Gas Storage Executive Summary
an estimated $55.3 million to $344.2 million in climate-related impacts from the approximately
5.7 BCF of gas released into the atmosphere, which PHMSA estimated based on the social cost
of methane (see Section 6.2 for details).
As part of the regulatory impact analysis for this final rule, PHMSA also evaluated the impacts of the
rule with respect to various administrative requirements. PHMSA determined that the rule:
 Would not have “a significant impact on a substantial number of small entities” (no
SISNOSE) under the Regulatory Flexibility Act (RFA). Section 8.2 details the analysis of
small entity impacts.
 Does not impose enforceable duties on State, local, or tribal governments or on the private
sector of $151 million in any one year and therefore does not have implications under Section
202 of the Unfunded Mandates Reform Act (UMRA) of 1995.
 Does not have federalism implications because it does not impose substantial direct
compliance costs on State or local governments.
 Will increase the cost of transporting natural gas only slightly and by much less than the
1 percent threshold suggestive of potential significant adverse impacts on energy supply,
distribution, or use. Therefore no Statement of Energy Effects is needed under Executive
Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply,
Distribution, or Use.
 Will change the information collection requirements associated with certain natural gas
storage facilities. PHMSA estimated changes in reporting and recordkeeping burden and is
submitting a revised Information Collection Request (ICR) to the Office of Management and
Budget (OMB) for approval under the Paperwork Reduction Act.
disclosure of the details of costs incurred. In this case, it is unclear from Sempra’s disclosure whether the reported costs include
estimates of business losses from the unavailability of the Aliso Canyon facility.
ES-4

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Regulatory Impact Analysis: Underground Natural Gas Storage 1. Introduction
1 Introduction
This report provides the estimated costs and benefits of the Interim Final Rule (IFR) to incorporate
consensus standards for underground natural gas storage facilities. PHMSA is promulgating the IFR
to address critical safety gaps and protect the public and the environment from natural gas releases
from underground storage facilities. The analyses described in this report fulfill the requirements of
Executive Orders 12866 and 13563 to prepare an assessment of the benefits and costs of the rule as
well as reasonably feasible alternatives. They also meet PHMSA’s statutory requirement for risk
analysis for new rules (49 USC 60102 et. seq.).
1.1 Purpose
In this IFR, PHMSA is adopting two American Petroleum Institute (API) Recommended Practices
(RP):6 API RP 1170, “Design and Operation of Solution-mined Salt Caverns used for Natural Gas
Storage” (July 2015), and API RP 1171, “Functional Integrity of Natural Gas Storage in Depleted
Hydrocarbon Reservoirs and Aquifer Reservoirs” (September 2015) (API, 2015a; API, 2015b). The
RPs describe a range of measures that operators of underground natural gas storage facilities should
implement to ensure the safety of their operations, including construction, maintenance, risk-
management, and integrity-management procedures. The IFR makes these provisions mandatory
unless operators provide justification in their program or procedural manuals as to why compliance
with a provision of the RP is not practicable and necessary for the safety of a particular facility.
PHMSA is issuing this IFR as an urgent first step7 in reducing the likelihood of incidents such as the
2015 Aliso Canyon natural gas leak in the future. Rapid incorporation of API RP 1170 and 1171 into
PHMSA’s regulations will require operators to assess the operational safety of their underground
natural gas storage facilities and document the implementation of identified safety solutions.
After this IFR incorporating API RP 1170 and 1171 becomes effective, PHMSA and its state partners
will monitor and enforce operators’ implementation of the requirements. After issuance of this IFR,
as a second phase, PHMSA will further investigate the need for additional regulatory requirements
for underground natural gas storage incidental to transportation. PHMSA intends to hold a public
meeting, and may pursue an additional rulemaking to address remaining safety concerns.
1.2 Need for Action
Following the accident at Aliso Canyon in 2015, the U.S. Congress recognized the need and urgency
to address safety gaps at underground natural gas facilities in enacting the PIPES Act of 2016 (Public
6 PHMSA participated, along with the Federal Energy Regulatory Commission (FERC), several state regulatory agencies, and
numerous industry representatives, in the development of the two API RPs.
7 These measures complement Advisory Bulletin ADB–2016–02 PHMSA issued on February 5, 2016 (81 FR 6334). The
advisory bulletin recommended that operators of underground natural gas storage facilities review their operating, maintenance,
and emergency response activities to ensure that the integrity of underground natural gas storage facilities is properly maintained.
This bulletin informed operators about recommended practices and urged operators to take all necessary actions to prevent and
mitigate breach of integrity, leaks, or failures at their underground natural gas storage facilities to ensure the safety of the public
and operating personnel and to protect the environment.
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Regulatory Impact Analysis: Underground Natural Gas Storage 1. Introduction
Law 114-183).
8 The PIPES Act requires PHMSA, not later than 2 years after the date of enactment of
the PIPES Act of 2016 and in consultation with the heads of other relevant Federal agencies, to issue
minimum safety standards for underground natural gas storage facilities. In issuing minimum safety
standards for underground storage facilities, PHMSA must: “(1) consider consensus standards for the
operation, environmental protection, and integrity management of underground natural gas storage
facilities; (2) consider the economic impacts of the regulations on individual gas customers; (3)
ensure that the regulations do not have a significant economic impact on end users; and (4) consider
the recommendations of the Aliso Canyon natural gas leak task force established under section 31 of
the PIPES Act of 2016.”
Lapses in operation and maintenance at underground natural gas storage facilities can and has
resulted in accidents. Industry standards and recommended practices such as API RP 1170 and RP
1171 describe measures that industry representatives have agreed on as representing good operating
practices. Although these recommended practices may be widely followed and implemented, they are
not enforceable regulations until incorporated into 49 CFR Part 192 by the IFR. In the absence of
regulations mandating the implementation of safety measures for the operation of underground
natural gas storage facilities, including the discovery and repair of hazardous conditions, operators
may not always implement those safety measures, thereby increasing the potential harm to the public
and environment. The absence of explicit regulatory requirements also limits PHMSA’s ability to
pursue enforcement against operators that fail to implement safe practices.
1.3 Report Organization
The remainder of this report is organized as follow:
 Section 2 provides an overview of the natural gas storage industry and the facilities and operators
expected to be subject to the IFR requirements, described in Section 3.
 Section 4 describes the analysis framework, including the baseline which reflects the practices
currently implemented by facility operators or expected to be implemented by the time the IFR
would be effective, absent the regulatory action.
 Sections 5 and 6 discuss the incremental costs and benefits, respectively, expected to arise from
implementation of the IFR relative to the baseline described in Section 4.
 Section 7 discusses uncertainties and limitations of the analysis and indicates the direction of any
known bias.
 Section 8 provides information on analyses and evaluations that fulfill requirements in other
Statutes and Executive Orders to evaluate the costs, benefits, or economic impacts of new
regulations.
Additional sections and appendices provide cited references and supporting data.
8 Protecting our Infrastructure of Pipelines and Enhancing Safety Act of 2016, signed into law on June 22, 2016.
1-2

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Regulatory Impact Analysis: Underground Natural Gas Storage 2. Industry Profile
2 Overview of the Natural Gas Storage Industry
Underground storage of natural gas offers important benefits to the U.S. energy supply infrastructure,
notably the ability to manage seasonal variations in natural gas demand and to provide a buffer for
changing production levels. Significant growth in domestic natural gas production from shale gas in
the last decade has prompted renewed interest and investment in storage capacity. Between 1995 and
2014, total natural gas storage capacity increased by nearly 16 percent to a total of 9,233 BCF (EIA,
2016b).
The Energy Information Administration (EIA) reports that 3,600 BCF of natural gas was injected
into underground storage facilities in 2015 (EIA, 2016a) – a volume of natural gas valued at over
$15 billion.9 For comparison, total natural gas consumption in the United States in 2015 was
27,473 BCF (EIA, 2016d).
There are three primary types of natural gas storage facilities (fields) in the United States (EIA,
2015):
 Depleted oil and gas reservoirs are the most common type of storage, representing approximately
81 percent of the total working gas capacity and 77 percent of the total design capacity in the
United States. As the name implies, these facilities are reservoirs that were previously used to
produce oil and/or gas and have been converted for storage by repurposing the production wells
and aboveground equipment to inject and withdraw gas as needed to build up storage or meet
demand.
 Salt caverns (salt dome) are geological formations that have been leached or mined out of their
salt deposits. These facilities represent about 11 percent of the total working gas capacity and
8 percent of the total design capacity.
 Aquifers are natural water-bearing formations that have been converted to store gas. They
represent the remaining 9 percent of the total working gas capacity and 15 percent of the total
design capacity.
2.1 Storage Fields
PHMSA estimates that there were 390 active natural gas storage fields10 in the United States in 2015,
distributed across 31 states (EIA, 2016e; Federal Energy Regulatory Commission (FERC), 2016; and
PHMSA, 2016b). These fields had an aggregate storage capacity11 of 9,155 billion cubic feet (BCF)
and a working capacity12 of 4,756 BCF (EIA, 2016e). Facilities used for interstate commerce
9 Value is based on the citygate price of natural gas of $4.25 per thousand cubic foot in 2015. Citygate refers to a point or
measuring station at which a distributing gas utility receives gas from a natural gas pipeline company or transmission system
(EIA, 2015).
10 PHMSA used EIA-191 for 2015 as primary data to determine the number of active fields. The definition of a field is based on
the number of records for which EIA indicates the status as “Active” (EIA, 2016e). Note that other available data (FERC, 2016;
PHMSA, 2016b) may subdivide or group fields, resulting in different counts of natural gas storage facilities.
11 Total natural gas storage capacity is the maximum volume of natural gas that can be stored in an underground storage facility
in accordance with its design, which comprises the physical characteristics of the reservoir, installed equipment, and operating
procedures particular to the site (EIA, 2015).
12 Working gas is the volume of gas in the reservoir above the level of base gas. Working gas is available to the marketplace
(EIA, 2015).
2-1

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Regulatory Impact Analysis: Underground Natural Gas Storage 2. Industry Profile
represented approximately 60 percent of the working capacity while intrastate facilities represented
the remaining 40 percent. Exhibit 2-1 summarizes the data by state. For this analysis, a natural gas
storage facility is equivalent to a unique gas field record in EIA-191 data (EIA, 2016e).
Exhibit 2-1: Underground Natural Gas Storage by State in 2015.
State Number of
Active Fields1
Design Capacity (BCF)3 Working Capacity (BCF)3
Interstate2 Intrastate2 Total Interstate2 Intrastate2 Total
Alaska 5 0.0 83.6 83.6 0.0 67.9 67.9
Alabama 2 0.0 43.6 43.6 0.0 33.2 33.2
Arkansas 2 0.0 21.9 21.9 0.0 12.2 12.2
California 14 0.0 601.8 601.8 0.0 375.5 375.5
Colorado 10 100.8 29.4 130.2 52.1 11.7 63.8
Illinois 27 135.9 851.4 987.3 46.5 255.6 302.1
Indiana 20 12.2 99.1 111.3 5.0 28.4 33.4
Iowa 4 288.2 0.0 288.2 90.3 0.0 90.3
Kansas 16 271.8 10.5 282.3 116.7 5.9 122.6
Kentucky 22 168.2 52.1 220.3 79.3 28.3 107.6
Louisiana 17 669.5 55.0 724.4 406.5 39.2 445.7
Maryland 1 64.0 0.0 64.0 18.3 0.0 18.3
Michigan Minnesota 44 435.7 644.9 1,080.6 282.5 403.2 685.7
1 0.0 7.0 7.0 0.0 2.0 2.0
Mississippi 12 287.8 44.0 331.8 169.2 32.2 201.4
Missouri 1 0.0 13.8 13.8 0.0 6.0 6.0
Montana 4 287.2 89.0 376.2 164.4 33.1 197.5
Nebraska 1 34.9 0.0 34.9 14.8 0.0 14.8
New Mexico 2 68.6 20.5 89.1 44.0 15.7 59.7
New York 26 229.3 11.3 240.6 122.5 3.5 126.0
Ohio 22 402.9 171.8 574.8 167.5 63.3 230.7
Oklahoma 12 196.8 179.2 376.0 104.7 87.7 192.4
Oregon 7 0.0 29.6 29.6 0.0 15.9 15.9
Pennsylvania 47 737.6 28.5 766.1 411.8 15.5 427.3
Texas 32 326.3 515.9 842.2 210.0 322.6 532.6
Utah 3 124.5 0.0 124.5 54.9 0.0 54.9
Virginia 2 0.0 9.5 9.5 0.0 5.4 5.4
Washington 1 46.9 0.0 46.9 24.6 0.0 24.6
West Virginia 26 488.6 8.7 497.3 229.9 3.3 233.1
Wyoming 7 131.0 24.1 155.0 68.2 4.9 73.2
U.S. Total 390 5,508.5 3,646.3 9,154.8 2,883.7 1,872.0 4,755.7
1. Number of fields based on Form EIA-191 through 2015 (EIA, 2016e).
2. Interstate fields identified from the FERC (2016) list of jurisdictional fields and PHMSA (2016b) data. All other fields
are intrastate fields.
3. Capacity data based on EIA (2016e).
2.2 Number of Wells
The American Gas Association (AGA) publishes a report periodically on the natural gas storage
fields in the lower-48 states and Canada (AGA, 2014). The report provides field-level data on total
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Regulatory Impact Analysis: Underground Natural Gas Storage 2. Industry Profile
number of injection/withdrawal wells, the number of horizontal injection/withdrawal wells, and the
number of pressure control/observation wells. PHMSA used the AGA data to determine the number
of wells in each active field potentially subject to the regulation. The AGA report also provides the
minimum and maximum depth to the formation, among other information about the geological
characteristics of each field. PHMSA used this information to classify the wells in three depth
categories: 3,500 feet or less; 3,501 feet to 7,000 feet; and greater than 7,000 feet.
Specifically, PHMSA matched the fields identified in the EIA data described in Section 2.1 to the
corresponding information in the AGA report for each field and transferred data on the number of
injection/withdrawal wells, the number of horizontal injection/withdrawal wells, and the number of
pressure control/observation wells.
The AGA report does not include data for fields in Alaska. PHMSA estimated the number of wells in
these fields based on their storage capacity and the ratio of wells to total storage capacity for active
fields in the lower-48 states (0.51 well per BCF of storage capacity). PHMSA further assumed that
wells in Alaska are 3,500 feet or less in depth, as this is the most common depth category for fields in
the lower-48 states.
Fields reported in the AGA survey but not in EIA data were left out of the analysis. In some cases,
AGA provides information for combined fields (e.g., Fink and Kennedy together) that are listed
separately in the EIA data (Fink and Kennedy as two fields). In that case, PHMSA assigned the wells
to one of the EIA listed fields.
Based on these data, PHMSA estimated that there are a total of 16,991 injection/withdrawal wells
and pressure control/observation wells within the 390 active fields.13 PHMSA seeks comment,
supported by data, on this estimate of the number of wells.
Many of these wells are decades old. For example, the well involved in the October 2015 Aliso
Canyon accident (see Section 6.1) was drilled in 1953 and was repurposed for natural gas storage in
1972. This age is not exceptional: according to AGA data, approximately 60 percent of active
injection, withdrawal, pressure control or observation wells are located in storage fields that were
activated before 1960 (AGA, 2014). Although AGA does not provide data on the age of individual
wells, it is reasonable to expect that many wells are developed by the time a storage facility starts
operating. The Interagency Task Force on Natural Gas Storage Safety (2016) highlights growing
concerns regarding the age of the natural gas storage infrastructure as it affects risk. Wells reflect
material, technology, and design factors applicable at the time they were constructed and many may
not meet design criteria for new wells. Over time, corrosion, other environmental processes, and
mechanical stresses from injection and withdrawal of natural gas can weaken well integrity. Wells in
depleted oil fields may have been designed for lower pressure than the stress they are now subject to.
Further many of these wells were not designed with redundant barriers to gas migration and present
riskier, single points of failure.
13 PHMSA notes that this number is slightly lower than estimates provided in some other sources. For example, in its letter to
PHMSA, INGAA (2016) stated that “there are approximately 17,500 active and observation storage wells in these fields.”
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Regulatory Impact Analysis: Underground Natural Gas Storage 2. Industry Profile
2.3 Operators
Entities that operate natural gas storage include interstate and intrastate pipeline companies, local
distribution companies (LDCs) and independent storage providers. These entities are classified into
North American Industry Classification System (NAICS) code 486210: Pipeline Transportation of
Natural Gas. The most recent Economic Census shows total revenue for this sector of $23 billion in
2012, with 125 firms and 2,118 establishments (U.S. Census, 2012). Following the NAICS definition
of the sector, these figures include revenue and entities involved in the storage of natural gas in either
underground, aboveground, or LNG facilities, or in natural gas transmission. As further discussed in
Section 8.2, the Small Business Administration (SBA) defines entities in this sector as small if they
have annual receipts of $27.5 million or less (SBA, 2016).
As described by EIA (2015), the owners or operators of storage facilities do not necessarily own the
natural gas held in storage. In fact, most working gas held in storage facilities is held under lease
with shippers, LDCs, or end users who own the gas. The type of entity that owns or operates the
facility determines to some extent how that facility's storage capacity is utilized. For example,
interstate pipeline companies rely heavily on underground storage to balance load and manage
system supply on their long-haul transmission lines. FERC regulations allow interstate pipeline
companies to reserve some portion of their storage capacity for this purpose, but the bulk of their
storage capacity is leased to other industry participants under open access rules. Intrastate pipeline
companies also use storage capacity and inventories for similar purposes, in addition to serving
customers.
Based on the field-level data described above, 124 companies operate the 390 active fields. Exhibit
2-2 lists the top 10 operators in terms of total working capacity in 2015. These operators accounted
for approximately half of the total working capacity, total design capacity, and number of wells.
Exhibit 2-2: Top 10 Underground Natural Gas Storage Facility Operators by Working Capacity in
2015; in Alphabetical Order.
Operator Number of
Active Fields
Total Working
Capacity
(MCF)
Total Design
Capacity
(MCF)
Number of
Wells
ANR Pipeline Company1 14 191.2 317.0 932
Columbia Gas Transmission LLC 32 282.5 677.7 3,362
Consumers Energy Company 14 148.3 303.2 981
Dominion Transmission INC 15 417.6 754.4 1,431
Michigan Consolidated Gas Company 5 230.0 306.4 102
Natural Gas Pipeline Co. of America 8 288.0 602.1 691
Northern Illinois Gas Company 8 149.7 466.3 516
Pacific Gas and Electric Company 3 102.2 173.0 116
Southern California Gas Company 4 135.3 266.9 196
Williston Basin Interstate Pipeline 2 192.8 350.4 203
Top 10 Operators’ Share of U.S. Total 27% 45% 46% 50%
Sources: Form EIA-191 through 2015 (EIA, 2016e); AGA (2014).
1 Does not include storage fields operated by affiliated companies and subsidiaries.
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Regulatory Impact Analysis: Underground Natural Gas Storage 2. Industry Profile
As discussed further in Section 8.2, natural gas storage facility operators include four entities that
meet SBA’s definition of a small business, including one small municipal government.
2.4 Regulation of Underground Natural Gas Storage Facilities
FERC has jurisdiction over storage facilities engaged in interstate commerce of natural gas; these
facilities represent approximately 60 percent of the total storage capacity and total working capacity
in the United States (see Exhibit 2-1). With the implementation of FERC Order 636 in 1994,
interstate pipeline companies have been required to operate their storage facilities on a
nondiscriminatory or open-access basis14 (EIA, 2015). FERC reviews rates for storage and storage-
related services under the authority of § 4(f) of the Natural Gas Act of 1938, but does not set safety
requirements for fields under its jurisdiction.
The U.S. Environmental Protection Agency (EPA) oversees Section 112(r) of the Clean Air Act
which aims to “prevent the accidental release [of extremely hazardous substances] and to minimize
the consequences of any such release” from stationary sources. 42 U.S.C. § 7412(r)(1). Section
112(r)(7) also authorizes EPA to publish regulations that impose accident prevention and emergency
response requirements on stationary sources that hold more than a threshold quantity of certain
regulated substances in a process. EPA’s “Risk Management Plan” regulations are codified at 40
CFR 68. However, these regulations specifically exempt facilities that are subject to oversight or
regulation under 49 CFR parts 192, 193, or 195, or a state natural gas or hazardous liquid program
for which the state has in effect a certification to DOT under 49 U.S.C. section 60105.
Facilities engaged in intrastate commerce may be regulated by the oil and gas commission,
environmental protection department, or other government agency of the state where they are
located. As of May 2016, PHMSA found that of the 16 states with intrastate underground natural gas
storage facilities (out of the total of 30 states with storage facilities), ten states had promulgated or
proposed regulations requiring operators to implement preventive measures such as mechanical
integrity testing to prevent the accidental release of natural gas from storage facilities. Exhibit 2-3
summarizes the requirements applicable to intrastate facilities in the ten states, focusing specifically
on requirements pertaining to mechanical integrity assessments and tests. As shown in the table,
existing or proposed regulations in nine states require well mechanical integrity tests every 10 years
or more frequently.15
While PHMSA has jurisdiction over interstate and intrastate fields, it currently does not have safety
requirements under 49 CFR Part 192 covering the wells and wellbore tubing and casing. The absence
of federal safety regulations over interstate facilities and of state regulation over much of the
intrastate facilities leaves over three quarters of natural gas storage capacity as currently unregulated,
based on working gas capacity. The gap also means that an estimated 13,682 wells out of the total
16,991 active storage wells (81 percent of wells) are currently unregulated.
14 Open access means that the working gas storage capacity (beyond what may be reserved by the pipeline/operator to maintain
system integrity and for load balancing) at each site must be made available to third parties (i.e., shippers or customers) on a first-
come, first-served basis at nondiscriminatory rates (EIA, 2015).
15 The tenth state, Michigan, exempts natural gas storage wells from the periodic testing requirements applicable to other types
of injection wells.
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Regulatory Impact Analysis: Underground Natural Gas Storage 2. Industry Profile
Exhibit 2-3: Summary of State Mechanical Integrity Requirements for Natural Gas Storage
State Regulation Summary of Requirements1
Alabama Alabama Gold Book,
400-5-7-.01
 Test for internal mechanical integrity prior to storing gas using
approved method and demonstrate internal mechanical integrity at
least every five years thereafter.
 Conduct tests for fluid movement along the annular space outside the
wellbore when deemed necessary by the state.
California Chapter 4:
Development,
Regulation, and
Conservation of Oil and
Gas Resources;
Subchapter 1: Onshore
Well Regulations
(California Department
of Conservation, 2016b)
 Mechanical integrity tests of all storage wells on a 5-year interval.
 Daily inspections of gas wellheads, using gas leak detection
technology.
 On-going measurement of annular gas pressure or annular gas flow
within wells.
 Regular testing of all safety valves – surface and subsurface.
 Establish minimum and maximum pressure limits for each gas
storage facility.
 Comprehensive risk management plans that evaluate risks at the
facility including corrosion of pipe and equipment.
Illinois Illinois Administrative
Code: Title 62, Part
240. Subpart R:
Requirements in
Underground Gas
Storage Fields and for
gas Storage and
Observation Wells
 Permit application and review process.
 Internal mechanical integrity performed prior to initial injection for
newly permitted Class II UIC well, following certain changes, and at
least once every 5 years.
Indiana Indiana Administrative
Code. Article 16: Oil
and Gas
 One of the following methods must be used to evaluate mechanical
integrity of the casing, tubing or packer: (1) After an initial pressure
test, monthly monitoring of annulus pressure (at a positive value) by
the owner or operator to be reported to the division no less frequently
than quarterly. (2) Pressure testing with liquid. Where pressure testing
is performed, the casing-tubing annulus above the packer must be
filled with fluid and tested, with no more than a three percent pressure
differential over a thirty-minute period, not less than once every five
years under the supervision of a division representative at a pressure
of no less than 300 pounds per square inch.
 One of the following methods must be used to evaluate mechanical
integrity to prevent migration of fluids: (1) The results of a temperature
or noise log. (2) Records demonstrating the presence of cement
adequate to prevent the migration of fluids in the well bore. (3) A
radioactive tracer survey.
 The division director may authorize an alternative test only where the
test reliably demonstrates the mechanical integrity of a well.
 In conducting and evaluating a test authorized by this section, the
owner or operator and the director shall apply methods and standards
generally accepted in the petroleum industry. When reporting the
results of a mechanical integrity test to the director, an owner or
operator shall include a description of any test and method used.
When evaluating a mechanical integrity test, the division director shall
review monitoring and other test data submitted since the previous
evaluation.
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Regulatory Impact Analysis: Underground Natural Gas Storage 2. Industry Profile
Exhibit 2-3: Summary of State Mechanical Integrity Requirements for Natural Gas Storage
State Regulation Summary of Requirements1
Kansas Kansas Department of
Health and Environment
K.A.R. 28-45a-14
 Hydraulic pressure test for each underground natural gas storage well
or storage cavern every five years.
 Integrity tests (a) After each workover; (b) before injecting working
gas into any existing underground natural gas storage well; and (c)
before plugging the well.
 Integrity test must be conducted at the maximum allowable operating
pressure.
 Casing evaluation for each underground natural gas storage well
using magnetic flux, ultrasonic imaging or alternative substantially
equivalent evaluation method
 Casing evaluation (a) every 10 years; (b) before the injection of
working gas in an existing underground natural gas storage well; and
(b) after any workover in which the injection string is pulled, if present.
Kentucky Oil and Gas
Regulations. 805 KAR
1:110. Underground
injection control
 Demonstrate mechanical integrity of new and existing Class II
injection wells.
 Submit a plan to demonstrate mechanical integrity with the application
for permit to inject.
 Use one of the following methods to evaluate the absence of
significant leaks: (a) Following an initial pressure test, monitoring of
the tubing and casing annulus pressure with sufficient frequency to be
representative, as determined by the division, while maintaining an
annulus pressure different from atmospheric pressure measured at
the surface; (b) A pressure test performed with liquid or gas; or (c)
Records of monitoring demonstrating the absence of significant
changes in the relationship between injection pressure and injection
flow rate for Class II enhanced recovery wells.
 Use one of the following methods to confirm the absence of fluid
movement: (a) The results of a temperature log or noise log, cement
bond log; (b) Cementing records demonstrating the presence of
adequate cement to prevent a migration; or (c) other methods
approved by the administrator.
 Perform mechanical integrity test on the annulus of the tubing and
casing. A minimum pressure of 300 psi shall be applied to the
annulus of the tubing and casing. The well is considered to have
mechanical integrity if, at the end of 30 minutes, there is no more than
a plus or minus of 3 percent change of the test pressure on the
gauge.
 A division field inspector must witness and approve a mechanical
integrity test.
 The division may require higher test pressures to be used when the
anticipated injection pressure will be high.
 The test results shall be filed on the Certificate of Mechanical
Integrity, Form ED-22.
 The owner or operator of a Class II well shall schedule at 5-year
intervals or less, mechanical integrity test.
 The owner or operator shall certify the test results to the division in
writing within fifteen days of completion of the test.
 The owner or operator shall not perform mechanical integrity test of a
Class II well without giving written notice to the division within fifteen
calendar days prior to the proposed test date.
 The division shall then notify the owner or operator of the earliest
possible date available to test the well.
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Regulatory Impact Analysis: Underground Natural Gas Storage 2. Industry Profile
Exhibit 2-3: Summary of State Mechanical Integrity Requirements for Natural Gas Storage
State Regulation Summary of Requirements1
Michigan Michigan DEQ. Office of
Oil, Gas, and Minerals.
Part 615, Chapter 324
 Before injecting fluid into a newly drilled well or previously existing
well newly converted to an injection well to be utilized for gas storage,
a permittee of an injection well shall provide for a test of the
mechanical integrity of the casing, by a qualified person, utilizing
either a pressure test at a bottom hole pressure of not less than the
maximum expected operating pressure of the gas storage field or an
equivalent test approved by the supervisor.
 Regulations exempt injection wells utilized from gas storage from
requirements to develop a plan to conduct 5-year mechanical integrity
tests of casing (§§ 324.201 and 324.805).
Mississippi Title 53: Oil, Gas and
Other Minerals. Rule
64: Underground
Storage Wells of
Liquefied Compressed
Gases, Crude Oils,
Refined Hydrocarbons,
Compressed Air and
Natural Gases in
Reservoirs Dissolved in
Salt Beds
 Design (including casing program), permitting, operating and reporting
requirements.
 Cavern mechanical integrity test at least every five years.
 For injection wells, use one of the following methods must be used to
evaluate the absence of significant leaks: 1) pressure test with liquid;
2) Monitoring of annulus pressure.
Pennsylvania Pennsylvania’s Oil and
Gas Act (Act 223)
Tile 58. Chapter 11. Oil
and Gas Act
 Case and cement gas storage wells to ensure no gas can leak from
them.
 Conduct monthly inspections of all gas storage wells and all wells
used for observation.
 Annually inspect the gas storage reservoir and storage protective
area to make sure no gas is leaking or other hazardous condition
exists.
 Implement gas storage well monitoring and integrity testing programs
once every five years.
 Not exceed pressures that may cause the gas to begin leaking.
 Notify DEP within 24 hours of making emergency repairs to gas
storage wells and submit a written explanation of the emergency and
what action was taken within five days.
 Keep records of well inspection results and pressure data, integrity
testing data, and inspections of abandoned and plugged wells.
 Notify DEP 15 days before the gas storage well is plugged to prevent
migration of gas or other fluids within or outside of the well.
Texas Texas Administrative
Code. Title 16, Part 1,
Chapter 3, Rule §3.96
Underground Storage of
Gas in Productive or
Depleted Reservoirs
 Safety training. Prepare and implement a plan to train and test each
employee at each gas storage project on operational safety and
emergency response procedures to the extent applicable to the
employee's duties and responsibilities.
 Wellhead pressure. The wellhead pressure of each gas storage well
shall be continuously recorded, continuously monitored electronically,
or controlled by a preset high-low pressure sensor switch.
 Pressure reporting. Information regarding wellhead pressures for
each gas storage well shall be reported annually to the commission
on the prescribed form.
 Integrity testing:
‒ (1) Prior to commencing operations. Before beginning gas injection
operations, the operator shall pressure test the long string casing,
or the tubing-casing annulus if the well is equipped with tubing set
in a packer. Gas storage wells in which injection occurs through
casing shall be tested at the maximum authorized injection
pressure. Gas storage wells in which injection occurs through
tubing and packer shall be tested at no less than 500 psig.
‒ (2) Subsequent tests. Each gas storage well shall be pressure
tested in the manner provided in paragraph (1) of this subsection at
least once every five years to determine if there are leaks in the
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Regulatory Impact Analysis: Underground Natural Gas Storage 2. Industry Profile
Exhibit 2-3: Summary of State Mechanical Integrity Requirements for Natural Gas Storage
State Regulation Summary of Requirements1
casing, tubing, or packer. The commission, or its designee, may
prescribe a schedule and mail notification to operators to allow for
orderly and timely compliance with this requirement.
‒ (3) Alternatives to testing. As an alternative to the testing required
in paragraph (2) of this subsection, the tubing-casing annulus
pressure may be monitored and monitoring results described in the
annual monitoring report required by subsection (n) of this section,
provided that there is no indication of problems with the well. The
commission, or its designee, may also grant an exception for other
viable alternative tests or surveys.
‒ (4) District office notification. The operator shall notify the
appropriate district office at least 48 hours prior to conducting the
test required in paragraphs (1) or (2) of this subsection. Testing
shall not commence before the end of the 48-hour period unless
authorized by the district office.
‒ (5) Test records. A complete record of all tests shall be filed in
duplicate with the district office within 30 days after the testing.
‒ (6) Gas withdrawal wells exempt. Gas storage wells that shall be
used only for gas withdrawal are excluded from the requirements of
this subsection.
1 This table provides only a summary of selected requirements. Refer to the full text of each regulation for details.
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Regulatory Impact Analysis: Underground Natural Gas Storage 3. Regulatory Requirements
3 Summary of IFR Requirements
In this IFR, PHMSA is adopting two API RPs: API RP 1170, “Design and Operation of Solution-
mined Salt Caverns used for Natural Gas Storage,” and API RP 1171, “Functional Integrity of
Natural Gas Storage in Depleted Hydrocarbon Reservoirs and Aquifer Reservoirs.” The RPs describe
a range of measures that operators of underground natural gas storage facilities should implement to
ensure the safety of their operations, including construction, maintenance, risk-management, and
integrity-management procedures. The IFR makes these provisions mandatory unless operators
provide justification in their program or procedural manuals as to why compliance with a provision
of the RP is not practicable and necessary for the safety of a particular facility.
3.1 API Recommended Practices
The API RPs apply to both newly constructed and existing underground natural gas storage facilities.
For newly constructed facilities the API RPs have sections that address the storage integrity, design,
and construction of “new” underground natural gas storage facilities including the following
reservoir or cavern and well aspects: siting, integrity, geological characterization, and containment of
the reservoir or cavern; the design, well casing, wellhead, cementing, and environmental, safety, and
health aspects of the well; and the testing, commissioning, monitoring, and recordkeeping of the
well. Regarding the operations and maintenance activities for both new and existing wells, the API
RPs have requirements for the following activities: threat identification, risk assessments, preventive
and mitigative measures, and periodic review and reassessment; integrity demonstration, verification,
monitoring, and gas inventory assessment practices; site security and emergency preparedness and
response; and operational procedures, training, and records.
Tables in Appendix A summarize the scope of RP 1170 and RP 1171 and highlight operator actions
associated with selected recommended practices.
Notably, RP 1171 provides guidance on well mechanical integrity evaluation of reservoirs and salt
caverns. Well mechanical integrity tests, whether by pressure tests or usage of well logs that detect
corrosion (similar to a pipeline smart pig), are critical to an operator’s ability to monitor well
integrity and to determine whether the maximum well operating pressure can be sustained in light of
corrosion or other anomalous defects or non-conservative well casing design.
API RP 1170 and 1171 set general performance objectives but do not specify a mechanical integrity
test procedure or testing intervals. API RP 1170 and 1171 require operators to evaluate the integrity
of each well through the review of well design, completion, wellhead and downhole inspections, well
pressure monitoring and testing, and gas sampling. API RP 1171 gives a minimum test pressure of
new and modified well casings. API RP 1171 states that an operator should monitor for tubular
(casing and tubing) corrosion and evaluate corrosion impact on well integrity and operating pressure,
but does not define an inspection interval. API RP 1170 states that an operator shall have an integrity
monitoring program that includes identification of components to be monitored, monitoring methods,
cavern volume and inventory verification, analysis of data from inspections and reporting, and
periodic review of the program for effectiveness with no defined inspection interval. Sections 6 and 9
of API RP 1171 include a method for a mechanical integrity test for a new well or modified casing.
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Regulatory Impact Analysis: Underground Natural Gas Storage 3. Regulatory Requirements
In this instance, operators are required to test 1.1 times the maximum allowable operating pressure
for 30-minutes and verify that the pressure drop does not exceed 10 percent of initial pressure.
By adopting the API RPs, PHMSA is making the practices contained therein (i.e., practices that the
RPs say “shall” be implemented or that the operator “may consider”) mandatory for all natural gas
operators, unless an operator provides justification in its program or procedural manual as to why
compliance with a recommended practice for a particular well or facility is not practicable and not
necessary for safety. This would involve a documented, technical review that is signed by technical
reviewer and senior company management. PHMSA or its state partner would review such
justifications during compliance inspections and utilize our range of enforcement tools as necessary
to ensure variances are not utilized inappropriately. In addition, PHMSA is able to issue bulletins or
otherwise notify operators advising them of variances that have frequently been deemed
objectionable and should be avoided under most circumstances. This approach has worked well in
pipeline regulation involving incorporation by reference
After the IFR becomes effective, PHMSA and its state partners will monitor and enforce operators’
implementation of the requirements. This will include reviewing the integrity test interval established
by the operator and the methodology for establishing the interval for a particular well to ensure that it
is supported by sound technical analysis.
The IFR also specifies new reporting requirements for underground storage facilities by adding
requirements for an annual report under 49 CFR §191.17, incident reports for unintentional releases
of natural gas under §191.15, and safety-related conditions reports under §191.23. Additionally,
operators not currently registered with PHMSA will need to obtain an operator identification number
under §191.22.
The IFR specifies timelines for facilities to comply with the API RPs, relative to the effective date of
the rule. Thus, the IFR requires that facilities meet “the operations, maintenance, integrity
demonstration and verification, monitoring, threat and hazard identification, assessment, remediation,
site security, emergency response and preparedness, and recordkeeping requirements and
recommendations” of API RPs 1170 and 1171 no later than 12 months from the effective date of the
rule. This 12-month deadline includes establishment of a testing program to assess the mechanical
integrity of the wells and other components of the storage system. The compliance schedule does not
require integrity tests to be completed before the 12-month deadline, however. PHMSA expects that
wells will be tested over the next several years (5 to 10 years) according to risk-based priorities.
Section 8.5 in API RP 1171 describes the six principal components to the risk assessment process:
a) identification of potential threats and hazards to a storage facility; b) evaluation of likelihood of
events and consequences related to the events; c) determination of risk ranking to develop preventive
and mitigating measures to monitor and/or reduce risk; d) documentation of risk evaluation and
decision basis for preventive and mitigative (P&M) measures; e) provision for data feedback and
validation; and f) regular, periodic risk assessment reviews to update information and evaluate risk
management effectiveness.
PHMSA determined that, of the sets of actions described in the API RPs, the requirement to conduct
mechanical integrity testing of storage wells has the greatest potential to impose incremental costs on
facility operators. Site design and planning, risk assessment, pressure monitoring, instrument
calibration and other measures described in the API RPs are steps that operators already take to
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Regulatory Impact Analysis: Underground Natural Gas Storage 3. Regulatory Requirements
ensure the reliable and safe supply of natural gas. PHMSA based its determination on a review of
ongoing O&M and capital expenditures and existing risk assessment programs described in
testimonies to public utilities commissions to support rate recovery requests (e.g., SoCalGas, 2014;
Xcel Energy, 2015).
3.2 Regulatory Alternatives Considered by PHMSA
PHMSA considered one primary alternative to adopting the API RPs: Promulgating more stringent
testing requirements than provided in the API RPs.
16
Because of the Congressional mandate described in Section 1.2, PHMSA cannot consider a “no
action alternative” because it would be both inconsistent with Congress’ direction and would not
address the current risk to safety, public health or the environment. Therefore, due to PHMSA’s
limited discretion due to Congress’ mandate, PHMSA has eliminated the no-action alternative from
consideration.
PHMSA considered promulgating more stringent requirements for underground storage facilities to
further enhance operators’ ability to detect and address integrity issues that could cause a release.
The API RPs provide general performance goals for ensuring the integrity of the storage
infrastructure but leave specific criteria to the discretion of the operator, based on a risk assessment.
Based on information regarding Aliso Canyon and other major well incidents, as well as studies by
the industry, service providers, federal regulators, state governments, and academia that address the
risk and integrity issues of wells, PHMSA considered setting explicit criteria in a rulemaking that
would build and further expand on the principles laid out in RPs 1170 and 1171. For example,
PHMSA considered setting specific criteria for (1) determining the maximum allowable operating
pressure (MAOP) of the reservoir and (2) testing wells. PHMSA also considered requiring safety
valves. Going beyond existing consensus standards, however, would require a more extensive
development and review process involving technical studies that would take years to complete.
The Aliso Canyon incident highlighted the urgency of closing regulatory gaps. Although PHMSA’s
statutory authorization extends to the regulation of underground natural gas storage, the lack of
applicable federal downhole regulations currently leaves the agency with no effective means of
regulating the safety of interstate underground natural gas storage facilities generally. Proposing
major infrastructure requirements subject to extensive technical studies and notice and comment
proceedings prior to issuing this IFR would leave the public and the industry without any national
minimum safety standards for underground natural gas storage incidental to transportation for years.
It would also leave PHMSA without any inspection or enforcement authority for underground natural
gas storage facilities during the rulemaking process.
PHMSA also considered an alternative that would not mandate compliance with nonmandatory RPs
(absent an operator making the justification under new § 192.12(a)(6)). However, PHMSA rejected
this alternative because it cannot enforce voluntary provisions. Having an unenforceable
“regulation” is meaningless and would not be a regulation at all -- it would be no more than guidance
16 PHMSA determined that a second alternative, which would have incorporated the API RPs by reference but without making
the practices mandatory, was impracticable as it would limit PHMSA’s ability to enforce the safety standards.
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Regulatory Impact Analysis: Underground Natural Gas Storage 3. Regulatory Requirements
and would not satisfy the mandate that Congress gave to PHMSA in section 12 of the PIPES Act. In
PHMSA’s experience, one of the key reasons why enforceability is important is that it ensures a level
playing field for industry. While many operators are committed to safety and would conscientiously
follow voluntary RPs, some other companies may be tempted to cut corners, thereby putting
operators who invest in safety at a competitive disadvantage. The absence of mandatory requirements
applicable to all industry participants reduces regulatory certainty and can result in a race to the
bottom. Clear, enforceable regulatory requirements provide the public and operators confidence that
all operators are following the same minimum rules. PHMSA seeks public comments on the
advantages and disadvantages of this alternative.
Because the existing emergency situation necessitates immediate regulatory action, PHMSA opted
against this alternative at this time. As a second phase after issuance of this IFR, PHMSA will further
investigate the need for more detailed regulatory requirements for underground natural gas storage
incidental to transportation and may pursue an additional rulemaking to address remaining safety
concerns. This second phase would also benefit greatly from field observation and experience gained
in implementing the IFR.
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Regulatory Impact Analysis: Underground Natural Gas Storage 4. Analysis Baseline
4 Analysis Framework
4.1 Analysis Baseline
The baseline for the regulatory analysis represents PHMSA’s best assessment of conditions absent
the regulatory action. In the case of this IFR, the analytical baseline accounts for the practices
implemented by storage facility operators under existing federal and state regulations, various
industry standards and recommended practices, and ongoing initiatives.
4.1.1 Federal and State Regulations
As detailed in Section 2, PHMSA has safety authority over the underground storage facilities used in
natural gas pipeline transportation. However, the existing safety regulations in 49 CFR Part 192 do
not apply to the downhole underground storage reservoir for natural gas. Accordingly, there is no
regulatory requirement for the performance of mechanical integrity tests for wells in interstate fields.
On February 5, 2016, PHMSA issued Advisory Bulletin ADB–2016–02 (81 FR 6334). The advisory
bulletin recommended that operators of underground natural gas storage facilities review their
operating, maintenance, and emergency response activities to ensure that the integrity of
underground natural gas storage facilities is properly maintained. This bulletin informed operators
about recommended practices and urged operators to take all necessary actions to prevent and
mitigate breach of integrity, leaks, or failures at their underground natural gas storage facilities and to
ensure the safety of the public and operating personnel and to protect the environment. The bulletin is
not a regulation, however, and PHMSA cannot compel operators to implement the RPs or enforce
compliance.
A number of states have promulgated or proposed their own safety regulations for intrastate natural
gas storage facilities, including underground storage wells, and inspect and enforce these regulations.
See Section 2.4 for details. State requirements for integrity testing are part of the baseline for this
analysis and therefore operators of the wells located in intrastate fields within states that have
requirements functionally equivalent to the API RPs will not incur incremental costs as a result of the
IFR. One exception is Michigan, which as summarized in Exhibit 2-3, does not require mechanical
integrity tests for natural gas storage wells; accordingly, PHMSA assumed that operators of intrastate
facilities in Michigan may incur incremental costs under the IFR.17
Note that promulgation of the IFR will not preempt exiting state regulations if the state regulations
are stricter than federal regulations (e.g., state regulations require integrity testing on a specified,
more frequent basis than the API RPs PHMSA is incorporating in this IFR).
4.1.2 Existing Industry Practices and Implementation
Since the publication of API RPs in July 2015 and following the Aliso Canyon incident in October
2015, the natural gas storage and transportation industry has highlighted its commitment to ensuring
17 As summarized in Exhibit 2-3, Michigan exempts natural gas storage wells from 5-year mechanical integrity tests applicable
to other types of injection wells.
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Regulatory Impact Analysis: Underground Natural Gas Storage 4. Analysis Baseline
the safe storage of natural gas. The industry has made implementation of API RPs 1170 and 1171 an
explicit part of this commitment.
Overall, the natural gas pipeline industry has been supportive of the need to promulgate consistent
federal standards based on the API RPs. On January 20, 2016, INGAA, a trade association
representing the majority of interstate natural gas pipeline companies in the United States and a
participant in the development of API RP 1170 and 1171, petitioned PHMSA to incorporate both
standards by reference into 49 CFR Part 192. That petition, along with a February 11, 2016 letter
from INGAA, urged PHMSA to adopt API RP 1170 and 1171 as quickly as possible to put into place
a set of consensus standards for operators of underground storage facilities to follow in assessing
their facilities and establishing procedures to ensure safety.
On May 9, 2016 in response to PHMSA questions about existing implementation of the API RPs,
INGAA described the following actions regarding implementation of RP 1171 by natural gas storage
facility operators (INGAA, 2016):18
 Storage operators are actively conducting a gap analyses to assess their individual integrity
management practices compared to the requirements of RP 1171. In the interim, operators will
enhance their current programs as they work toward alignment with the RP. Examples of current
integrity activities undertaken by operators are monitoring for the presence of annular gas and
monitoring the injection and withdrawal flow rates and pressures at each storage reservoir.
 Operator personnel visit a well site multiple times annually and observe the wellhead assembly
and wellsite conditions each time. Pursuant to the RP, operators will conduct a standardized
inspection and documentation of their findings. All active storage wells will be inspected within
one year.
 Existing surface and subsurface shut-off valves systems will be tested at least annually per the
manufacturer’s recommendations and the operator’s procedures.
 Operators will conduct a risk assessment and investigate enhancing their existing integrity
management plans and procedures consistent with the requirements of the RP. INGAA estimated
that this initial program development will be completed within 15 months.
 Operators will evaluate the threats and hazards impacting storage wells and reservoirs utilizing
Table 1 (Section 8) in RP 1171 as supplemented based on site-specific conditions. Operators will
also assess the potential interaction of threats and hazards and perform periodic reevaluations of
these threats and hazards in order to account for changes in the likelihood or consequence of the
event potential. INGAA indicated that this task will be 50 percent complete within two years and
100 percent complete within three years.
 Operators will develop and implement appropriate preventative and mitigative (P&M) measures
utilizing Table 2 (Section 8) in RP 1171, as supplemented, to reduce the risk to storage facilities.
This will include routine condition monitoring activities and training personnel in these
procedures. Complete implementation of the P&M measures will be contingent upon the
successful and timely completion of the prior step, evaluating threats and hazards. Completion of
this step may take up to three years.
18 INGAA noted that a similar timeline for incorporating RP-1170 is under development and is expected to be fairly consistent
with that for RP-1171.
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Regulatory Impact Analysis: Underground Natural Gas Storage 4. Analysis Baseline
 Monitoring for tubular corrosion and evaluating the impact on well integrity and operating
pressure will be conducted using risk assessment. This will include an evaluation of tubular
integrity and identification of defects caused by corrosion or other chemical or mechanical
damage, corrosion potential of wellbore fluids and solids, annular and packer fluid corrosion
potential, and corrosion potential of current flow associated with cathodic protection systems.
INGAA indicated that this step will be completed for each active storage well within five years.
 Operators will evaluate the mechanical integrity of every active storage well using the plans and
procedures developed under the RP. Approximately 50 percent of the active wells will be
evaluated within two years and the remainder will be completed within five years.
INGAA expects some of the activities to run concurrently and others sequentially, and the time
required to finish all of the activities will be approximately seven to eight years.
PHMSA’s review of active storage facilities indicates that companies INGAA identified as members
on its website operate over half of the facilities, 61 percent of working gas capacity, and 86 percent
of the wells.19 Statements made by INGAA on behalf of its member companies suggest that a
significant fraction of active storage facility operators have already started incorporating the RPs in
their operations and would continue to do so even without a regulation. If so, the costs of the
integrity testing and other measures contained in the RPs are part of the baseline for this action.
In addition, several facility operators have made separate public statements regarding their program
for maintaining integrity of their storage facilities. PHMSA is aware of commitments made publicly
by Southern California Gas Company (SoCal), Public Service Company of Colorado, and Pacific
Gas and Electric Company (PG&E) to test all their natural gas storage wells to verify their integrity
(SoCalGas (2014); Xcel Energy (2015); PG&E (2016)). In reviewing company websites to determine
the size of business entities for the Regulatory Flexibility Analysis (see Section 8.2), PHMSA also
found descriptions of integrity assessment programs for Honeoye Storage and Puget Sound Energy’s
Jackson Prairie Gas Storage that include elements similar to those in the API RPs.20 The costs
incurred by these operators under these existing programs and commitments are also part of the
baseline for this action and not attributable to the IFR. Exhibit 4-1 lists the companies and the
number of fields and wells they operate. PHMSA did not conduct an exhaustive search of all facility
operators to determine whether they had existing programs or had made explicit, public
commitments to assess the integrity of their wells.
19 INGAA members are listed at http://www.ingaa.org/25/INGAAMembers.aspx (accessed June 10, 2016). PHMSA based its
review on the parent owner of each operator as described in Section 8.2.
20 For example, the corporate website for Honeoye Storage describes the company’s program as follows (emphasis added): “Well
Logging: To maintain and monitor the condition of gas well piping, we conduct an annual casing inspection logging program.
The majority of the well is below the surface and cannot be visually inspected without the use of sophisticated measuring
devices. Electronic tools are lowered to the bottom of the well bore, a distance that averages 2,800 feet below the ground surface,
and a computerized record is generated that summarizes the condition of the well pipe from the bottom of the well to the ground
surface. This requires HSC to contract with companies that operate specialized trucks equipped with masts, pressure controls, and
instruments utilized to record the data obtained from the “down hole” tools.” (Honeoye Storage, 2015)
Puget Sound Energy reported that it will comply with the latest PHMSA natural gas storage advisory bulletin (ABD-2016-02)
dated 2/5/2016 and API RP-1171 (Puget Sound Energy, 2016)
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Regulatory Impact Analysis: Underground Natural Gas Storage 4. Analysis Baseline
Exhibit 4-1: Operators with Existing Commitments to Conducting Integrity Testing
Company Name Number of Fields Number of Wells
HONEOYE STORAGE CORPORATION 1 38
PACIFIC GAS AND ELECTRIC COMPANY 3 116
PUBLIC SERVICE COMPANY OF COLORADO 3 46
PUGET SOUND ENERGY 1 103
SOUTHERN CALIFORNIA GAS COMPANY 4 196
Total 12 499
Sources: SoCalGas (2014); P&&E (2016); Xcel Energy (2015); Honeoye Storage (2016); Puget Sound Energy
(2016); Number of fields from EIA (2016e); Number of wells from AGA (2014).
4.1.3 Baseline Scenarios
For this analysis, PHMSA evaluated the impacts of the regulation relative to three distinct baselines
that differ in terms of the level of implementation with the RP measures in the absence of the
regulation:
 Full compliance: For this first scenario, PHMSA assumed that the entire industry would be
implementing the RPs in the absence of this rule. The costs associated with the measures
described in the RPs are therefore not attributable to the regulation. Incremental costs consist
only of those (minimal) costs associated with notifications or reporting to PHMSA, as such
reports would not be needed absent the regulatory requirement to provide information to the
government.
 Partial industry compliance: For this second scenario, PHMSA assumed that only those operators
who are INGAA members or have stated publicly that they are implementing the RPs would
implement the measures in the absence of this rule and that the regulation could therefore impose
an incremental costs on all other operators of interstate facilities or of intrastate facilities in states
without regulatory requirements. PHMSA considers this baseline to represent a lower bound
level of implementation in the absence of the regulation, as suggested by the response from
INGAA (2016) regarding current and planned activities, and the incremental costs therefore may
overstate the impacts of the IFR.
 Regulatory compliance only: For this last scenario, PHMSA assumed that only those operators of
intrastate facilities subject to existing state regulations would implement safety measures
contained in the RP. PHMSA judges this baseline as highly unlikely and the incremental costs
represent an upper bound of the costs that are attributable to the IFR.
For each of the baselines, DOT expects that all operators would comply with all nonmandatory
provisions in the RPs in the absence of the IFR except as justified in accordance with § 192.12(a)(6).
Given the potential that not all operators would implement the RPs or would do so within the
timeframe PHMSA specified in the IFR, PHMSA evaluated the costs, economic impacts, and
benefits of the IFR relative to the three baselines. The following sections detail this analysis.
4.2 Other Analysis Elements
In addition to the baseline described above, the analysis of the costs and benefits of this IFR
embeds other common elements discussed below.
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Regulatory Impact Analysis: Underground Natural Gas Storage 4. Analysis Baseline
4.2.1 Timeframe for the Analysis
The relevant timeframe for the analysis of the costs and benefits of the IFR is determined in part by
the expected implementation schedule and the life (i.e., periodicity) of compliance technologies or
procedures. Thus, PHMSA estimated the compliance costs accounting for when operators would be
expected to conduct the integrity tests on their wells and the interval between successive tests.
Similarly, PHMSA accounted for the benefits based on the timing of the compliance measures and
the expected duration of the resulting benefits.
As discussed in Section 5.1, PHMSA analyzed the costs and benefits of the IFR over a 20-year
period starting in 2016 and ending in 2035. This period reflects assumptions for the primary analysis
of a 10-year phase-in for completing mechanical integrity tests on all active wells and 10-year
interval between successive mechanical integrity tests. PHMSA also analyzed an alternative scenario
that assumes a shorter 5-year interval between integrity tests.
PHMSA annualized the costs over the period of analysis using discount rates of 3 percent and
7 percent.
4.2.2 Regulatory Alternatives
As discussed in Section 3.2, PHMSA considered and rejected one alternative to this IFR
(promulgating more stringent testing requirements than provided in the API RPs). Because the
alternative was not viable, PHMSA did not analyze its costs and benefits quantitatively.
4.2.3 Discounting of Future Costs and Benefits
The analytic framework includes two basic temporal components, which are used consistently
throughout the analysis of social benefits and social costs:
 Use of constant prices. This analysis applies a year 2015 constant price level to all future
costs and benefits.
 Discount rate and year. This analysis estimates the annualized value of future costs and
benefits using two discount rates: 3 percent and 7 percent. This is consistent with guidance
provided by the Office of Management and Budget (OMB) in Circular A-4, which
recommends that 3 percent be used when a regulation affects private consumption and
7 percent be used in evaluating a regulation that will mainly displace or alter the use of
capital in the private sector (OMB, 2003). The same discount rates are used for both benefits
and costs. All future cost and benefit values are discounted back to 2016.
4.2.4 Industry Growth Rate
For this analysis, PHMSA assumed that the number of storage fields, active wells, and operators
would remain the same during the period of analysis. PHMSA made this assumption due to the
difficulty of projecting changes in the number of underground storage facilities and wells over time.
Historical data show a 16 percent increase in underground storage capacity between 1995 and 2014
(EIA, 2016b). If this growth trend were to continue and additional wells were constructed and subject
to mechanical integrity test, then assuming that the number of wells would remain constant would
understate the costs of the IFR.
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Regulatory Impact Analysis: Underground Natural Gas Storage 5. Costs
5 Costs
The most significant potential cost associated with the IFR consists of the cost of conducting
mechanical integrity tests on the 16,991 wells in active natural gas storage fields.21 As discussed in
Section 4.1.3, information provided to PHMSA by industry representatives suggests that storage
facility operators already conduct mechanical integrity tests or will be conducting these tests in
accordance with the industry’s commitment to promote implementation of the API RPs. If so, then
there would be no incremental cost attributable to the IFR for these tests.
PHMSA understands that API RPs are not regulations and thus there is no enforcement mechanism.
As such, implementation may be incomplete in the absence of regulatory requirements, in which case
the IFR would result in incremental costs and benefits, relative to the baseline. As discussed in
Section 4.1.3, PHMSA evaluated baseline compliance scenarios that consider the incremental costs
to operators not currently subject to equivalent state requirements (under the regulatory compliance
only baseline) and also to operators not members of INGAA and without an integrity management
program for testing wells in the baseline (under the partial compliance baseline).
Other costs for the IFR are related to new PHMSA reporting requirements that go beyond the
recordkeeping required to implement the API RPs. PHMSA reporting requirements represent
incremental costs independent of the baseline level of API RP implementation, and as a result apply
to both the partial and full compliance baseline scenarios.
5.1 Costing Methodology
5.1.1 Mechanical Integrity Testing Costs
PHMSA expects that mechanical integrity testing costs will depend on the number of wells tested
and the depth of the wells. Exhibit 5-1 shows PHMSA estimates of mechanical integrity testing costs,
based on input from industry regarding the cost of setting up and running the mechanical integrity
tests for wells of varying depths. The values in Exhibit 5-1 represent the costs of conducting a
mechanical integrity test on an average individual well within a given depth range, including both
equipment and labor. Actual costs may vary depending on the location, well characteristics and other
factors. PHMSA assumes that logging costs include analysis of the results to determine any follow
up actions, such as the recommended timing for the next inspection.
Exhibit 5-1: Well Testing Costs by Depth Category (CD).
Cost Item 0-3,500 ft 3,501-7,000 ft >7,000 ft
Logging costs (noise, temp, bond, casing integrity,
caliper, pressure test) $60,000 $90,000 $130,000
Workover rig costs $50,000 $100,000 $200,000
Total $110,000 $190,000 $330,000
Source: Estimate provided to PHMSA by an industry representative.
21 As discussed in Section 3.1, PHMSA assumes that operators already conduct other actions described in the API RPs as part of
their existing safety procedures.
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Regulatory Impact Analysis: Underground Natural Gas Storage 5. Costs
PHMSA confirmed that the costs in Exhibit 5-1 are reasonable by comparing them with estimates
cited in other sources. For example, in a 2014 regulatory filing, SoCalGas provide cost estimates of
$390,000 (in 2013 dollars) per well for a weeklong testing process, including pressure and corrosion
tests (SoCalGas, 2014).22 The higher costs cited by SoCalGas are expected due to the higher price
levels in California and the depth of wells needing to be tested; of the four active storage fields
operated by SoCalGas, two are approximately 10,000 feet deep and the other two are nearly 7,000
feet deep.
PHMSA seeks comment and any available data on these estimates of the costs of mechanical
integrity testing for wells of various depths and in different areas of the country.
The second factor influencing costs is the number of wells to be tested in any given location. Because
some of the testing costs are associated with mobilizing personnel and equipment, PHMSA expects
that operators with multiple wells in the same area will realize economies of scale relative to the unit
costs for testing individual wells presented in Exhibit 5-1. Specifically, for this analysis, PHMSA
assumed that operators may save 10 percent, relative to the unit costs, when conducting tests on more
than 10 wells within the same field. PHMSA expects operators of fields with a large number of wells
to inspect a portion of their wells each year, whereas operators of smaller fields may conduct all
inspections in a single effort. For comparison, there are more than 10 wells at all 4 fields discussed
by SoCalGas in the 2014 regulatory filing (104 at Aliso Canyon; 29 at Honor Rancho; 21 at La
Goleta; and 42 at Playa del Rey).
PHMSA calculated the testing cost for each active field CF by multiplying the number of wells by the
cost corresponding to the field’s maximum depth to the formation, and applying a 10 percent
reduction to those fields with more than 10 wells (Equation 1).
𝑪𝑭 = 𝑵𝑭 × 𝑪𝑫 × 𝑭𝑵 (Equation 1)
where NF is the number of wells in field F
CD is the cost per well for a formation depth D based on Exhibit 5-1
FN is an adjustment factor based on the number of wells N (FN = 1.0 if N  10; FN = 0.9 if N
>10)
PHMSA summed field-level costs over all fields operated by a given company to derive the operator-
level costs summarized in Appendix B, and over all fields within a state or over the industry to
calculate costs presented in this section. As discussed above, PHMSA zeroed-out the costs for
operators who are listed as INGAA members or that have existing programs or for intrastate fields in
states with existing requirements as these costs are already reflected in the baseline.
5.1.2 Costs of Addressing Integrity Issues Identified through Testing
Integrity tests may reveal issues in the casing or other well components requiring repairs or other
corrective actions. The API RPs describe the types of repairs that operators would need to perform to
ensure the continued safe operation of the storage facility, including replacing the tubing,
22 SoCalGas had proposed conducting well logs for corrosion and pressure tests for integrity in their rate case (SoCalGas, 2014).
This testing is similar to the testing requirements of this rule.
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Regulatory Impact Analysis: Underground Natural Gas Storage 5. Costs
recementing, or plugging the well. These are corrective actions that would need to be performed at
some point to continue safe operation, and the knowledge gained through the integrity test merely
changes the timing of the repair which may avert more severe and costly repairs that would result
from leaks or minor issues that escalated to more costly ones due to a lack of preventative
maintenance. Further, the RPs give discretion to the operator on prioritizing repairs based on risk, so
that operators are able to plan for, and schedule, those repairs based on the information gained from
the inspections and tests rather than do repairs reactively when a leak occurs. However, operators
may accelerate repairs of conditions they discover during the inspections as compared to when those
repairs would have otherwise occurred.
The savings from avoiding leaks and having the ability to schedule capital expenditures based on risk
could offset cost implications from potentially having to conduct repairs sooner than currently done
in the baseline. There is considerable uncertainty involved in predicting when repairs would have
been discovered and addressed without the integrity test results and how this timing changes when
implementing the RPs. PHMSA anticipates that there is a significant difference in costs of preventive
maintenance as compared to measures that may need to be taken to control an ongoing release. In a
2014 rate case to the California Public Utilities Commission, SoCalGas described the advantage of a
SIMP program including mechanical integrity testing of wells at Aliso Canyon as follows: “By
establishing the additional and more robust SIMP inspections, and creating baseline assessments of
well conditions, the severity and extent of reactive maintenance may be reduced in the future, and the
time necessary to respond to indications of breaches in reservoir integrity and safety should be
greatly improved.” (SoCalGas, 2014; p. 21) Xcel Energy made similar arguments in their request to
the Colorado Public Utilities Commission to make changes to the existing maintenance program to
include testing the integrity of the gas wells associated with Xcel’s storage fields, noting that “failure
to maintain any component required to run the field can result in significant reliability concerns and
potentially significant subsequent O&M costs.” (Excel Energy, 2015; p. 66). PHMSA requests
comment on the size of savings from avoiding leaks and the ability to schedule capital expenditures
based on risk, and the cost of repairs.
5.1.3 Costs of Other RP Elements
While PHMSA expects the most significant costs resulting from implementation of the API RPs to
be those related to mechanical integrity testing, operators may also incur costs to implement the other
RPs elements summarized in Exhibits A-1 and A-2 (in Appendix A). For example, RP 1171
recommends that operators evaluate the threats and hazards affecting their storage wells and
reservoirs, assess the risk, and use this information to prioritize management actions. According to
RP 1171, the operators should update their assessment at a pre-defined frequency. The RP also
recommends that operators monitor well and related facilities and average reservoir pressure versus
inventory, to allow for the discovery and correction of any unexpected conditions. Records
developed in accordance with the RPs must be maintained for the life of the facility.
The RPs provide flexibility in how these other elements are implemented. PHMSA expects that
operators already conduct assessment, monitoring, planning, and recordkeeping activities as part of
normal business operations and may simply need to incorporate the existing procedures into their
program. Accordingly, PHMSA estimated the incremental burden and costs of these other RP
elements to be zero for this analysis. This assumption applies to all three baseline scenarios. There
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Regulatory Impact Analysis: Underground Natural Gas Storage 5. Costs
may be operators that do not conduct assessment, monitoring, planning, and recordkeeping to the
extent recommended in RP 1170 and 1171, and there will be additional costs for those operators as a
result of this IFR. PHMSA requests comment on the extent to which any operators may need to
supplement assessment, monitoring, planning, or recordkeeping in order to comply with this IFR.
5.1.4 Reporting Costs
PHMSA estimated that all 124 operators with active natural gas storage facilities will need to submit
an annual report to PHMSA and maintain records. In addition, a subset of operators may need to
submit safety-related condition reports or incident reports to PHMSA on an as needed basis.
Operators that do not currently report to PHMSA will need to register and request an operator
identifier (OPID). Operators may also update their registration as needed to reflect certain changes
such as changes in ownership.
For this analysis, PHMSA estimated the incremental burden associated with registration and
notification, recordkeeping, annual reports, safety related conditions reports, and incident reports.
The preamble to the IFR describes the annual reporting and recordkeeping burden. PHMSA
estimated the costs of recordkeeping and reporting requirements assuming that a compliance officer
would perform the necessary activities.
A review of existing operators shows that 100 of the total 124 operators of active underground
storage facilities have other operations that already require submittal of information to PHMSA.
PHMSA assumed that 24 operators may have to submit a new registration and that 25 operators may
need to revise their registration each year. PHMSA estimated a burden of one hour each for
registrations or notifications.
All 124 operators will need to maintain records and submit an annual report. Because assessment,
monitoring, planning, and recordkeeping activities are already conducted as part of normal business
operations and may simply need to be modified and formalized to comply with the RPs, PHMSA
estimated that the IFR will increase the recordkeeping burden by one hour per operator per year.
PHMSA assumed that the annual report by natural gas storage facilities will require an average of
8 hours, including the time to review instructions, gather data, and complete and review the form.
Because these operators are already subject to various reporting requirements to FERC, Public
Utilities Commissions, and other authorities, and because the information requested by PHMSA
should already be available, PHMSA expects that any additional set up costs for the first report will
be minimal.
PHMSA assumed that, on average, four operators (3 percent) may need to submit incident reports
and the same number may need to submit safety-related condition reports annually, with respective
burdens of 10 hours and 6 hours.
The IFR will make measures described in the API RPs mandatory. Operators who deviate from the
API RPs will need to include a justification in their program or procedural manuals as to why
compliance with a provision of the recommended practice is not practicable and not necessary for the
safety of a particular facility. This justification must be technically reviewed and documented by a
subject matter expert to ensure there will be no adverse impact on design, construction, operations,
maintenance, integrity, emergency preparedness and response, and overall safety and must be dated
and approved by a senior executive officer, vice president or higher with responsibility of the
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Regulatory Impact Analysis: Underground Natural Gas Storage
5. Costs
underground natural gas storage facility. PHMSA assumed that 12 operators (10 percent of
operators) per year would incur incremental cost to compile and maintain records justifying API RP
deviations, with each justification taking 8 hours to document.
Exhibit 5-2 summarizes the estimated recordkeeping and reporting costs.
Exhibit 5-2: Recordkeeping and Reporting Costs (2015$)
Hours
Total
Annualized
Annualized
Reporting Activity
of Filers
umber
per
Cost per
Cost (3%
Cost (7%
Report
Report
Costs?
Discount
Rate)
Discount
One-time registration
Rate)
24
1
$61
$1,467
$96
$129
Notifications
25
1
$61
$1,528
$1,528
$1,528
Recordkeeping
124
1
$61
$7,578
$7,578
$7,578
Annual report
124
8
$489
$60,621
$60,621
$60,621
Safety-related conditions report
4
6
$367
Incident report
$1,467
$1,467
$1,467
4
10
$611
$2,444
$2,444
$2,444
Recordkeeping for deviations
12
8
$489
$5,867
$5,867
$5,867
Total
$79,600
$79,633
"Source: PHMSA professional judgment (see Table 3-96 in PHMSA, 2016a)
2 Assumes hourly rate of $61.11 based on wage for compliance officers from Bureau of Labor Statistics ($40.74/hour;
see BLS (2016)) multiplied by 1.5.
3 Calculated as [number of filers] × [cost per report]
^ Cost per year calculated by annualizing the one-time registration costs over the 20-year analysis period using
3 percent and 7 percent discount rates.
5.2 Industry Compliance Costs
5.2.1 Full Industry Compliance Baseline
Under the first baseline scenario where the industry is already in full compliance with the RPs,
incremental costs attributable to the regulation for mechanical integrity testing and other procedures
are zero. PHMSA estimated the costs associated with reporting requirements at approximately
$79,600 per year (using a 7 percent discount rate), as detailed in Section 5.1.4 above.
Exhibit 5-3: Annualized Compliance Costs Relative to the Full Industry Compliance Baseline
Scenario (2015$)
Cost Component
3% Discount Rate
7% Discount Rate
Mechanical integrity testing
$0
$0
Other RP elements
$0
$0
Reporting'
$79,600
See Exhibit 5-2 for details
Total
$79,600
$79,633
$79,633
5.2.2
Partial Industry Compliance Baseline
To estimate incremental costs relative to the partial compliance baseline scenario, PHMSA first
determined the number of wells incrementally tested. PHMSA adjusted the number of wells by
subtracting (1) all wells at intrastate facilities in states with existing standards; (2) wells at facilities
operated by operators with existing integrity testing commitments (see Section 4.1.2; and (3) wells at
facilities operated by companies that are members of INGAA (see Section 4.1.2). Under these
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Regulatory Impact Analysis: Underground Natural Gas Storage
5. Costs
assumptions, 2,408 wells will be subject to testing under the regulation (referred as "applicable
wells" below), out of the total of 16,991 active wells in the United States.
PHSMA multiplied the number of applicable wells at each field by the cost corresponding to the field
depth to the formation summarized in Exhibit 5-1. Exhibit 5-4 shows the estimated compliance costs
by state, before accounting for a phase-in of the tests (i.e., assuming immediate implementation).
Appendix B presents estimated compliance costs by operator.
Exhibit 5-4: Incremental Integrity Testing Costs Relative to the Partial Industry Compliance
Baseline Scenario, by State.
State
Count of Applicable Wells'
Incremental Integrity
(Million 2015$)
Testing Costs
Total Annualized Integrit
(Million 2015$/Year)
Testing Costs
Alaska
165
$16.5
$2.2
Alabama
$0.0
$0.0
Arkansas
$1.4
$0.2
California
$0.0
$0.0
Colorado
$1.9
$0.3
Indiana
Illinois
$0.0
$0.0
$0.0
$0.0
lowa
$19.8
$2.6
Kansas
$23.6
$3.1
Kentucky
$0.0
$0.0
Louisiana
Maryland
$23.4
$3.1
$0.0
$0.0
Michigan
$101.4
Minnesota
$13.5
$6.5
$0.9
Mississippi
$4.8
$0.6
Missouri
$8.0
$1.1
Montana
$27.1
$3.6
Nebraska
New Mexico
$0.0
$0.0
5
$1.7
$0.2
New York
$9.6
$1.3
Ohio
$6.9
$0.9
Oklahoma
$5.1
$0.7
Oregon
$4.5
$0.6
Pennsylvania
3
$0.6
$0.1
Texas
$2.8
$0.4
Utah
$0.0
$0.0
Virginia
$000
$0.0
Washington
$0.0
$0.0
West Virginia
21
$3.7
$0.5
Wyoming
22
$2.3
$0.3
Count of applicable wells excludes fields operated by companies that are members of INGAA, operators with
existing integrity management programs, and intrastate fields in states with existing requirements. See Sections 4.1.1
and 4.1.2 for details.
the assumed 10-year phase-in period.
2 Represents the total costs of conducting mechanical integrity tests, before accounting for the timing of the tests over
3 Costs annualized using a 7 percent discount rate over 10 years (assuming tests conducted every 10 years).
5-6

<<<PAGE 36>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
5. Costs
For the primary analysis, PHMSA assumed that each well will be tested every 10 years. The costs of
implementing the integrity requirements in the RPs are approximately $30.9 million when annualized
over 10 years using a 3 percent discount and $36.1 million when annualized using a 7 percent
discount. PHMSA assumed immediate implementation of the requirements.
However, as discussed in Section 4.2.1, PHMSA assumes that facility operators will test their active
wells according to a schedule that reflects assessment of the relative risk across their operations. For
the primary analysis, PHMSA assumed a 10-year phase-in period with the first 10" of the wells
tested in Year 1, the second 10# in Year 2, etc. so that all wells will have been tested once by
Year 10. This schedule means that wells tested in 2016 would be tested again in 2026, wells tested in
2017 would be tested again in 2027, and so on.
As discussed in Section 3, API RPs do not specify an interval for testing and although ten years may
be reasonable, some operators may need to test more or less frequently based on site-specific risk
factors (e.g., age of the wells, operating pressures, casing conditions). To evaluate the effects of
different testing intervals on annualized costs, PHMSA also conducted an alternative analysis
assuming that operators would tests their well every five years.
Exhibit 5-5 summarizes the annualized costs for 10-year testing interval and an alternative 5-year
interval and assuming a 10-year phase-in period for implementing the mechanical integrity testing
program. As shown below, the estimated annualized costs of the requirements to test wells every ten
years are $27.2 million using 3 percent discount rate and $31.7 million using a 7 percent discount
rate, when phasing-in the requirements over ten years and applying the partial industry compliance
baseline (a 12 percent reduction as compared to immediate implementation). The estimated
annualized costs of testing wells every five years are $50.6 million and $54.5 million, using 3 percent
and 7 percent discount rates respectively (a 6 percent reduction). As noted previously, these costs are
for the scenario of only partial industry compliance with mechanical integrity tests in the absence of
federal regulatory requirements.
Baseline Scenario (Million 2015$)
Exhibit 5-5: Annualized Integrity Testing Costs Relative to the Partial Industry Compliance
Phase-in Period
Testing Interval
3% Discount Rate
7% Discount Rate
Immediate Implementation
10 Years
$30.9
$36.1
5 Years
$57.6
$61.9
Phase-in over 10 Years
10 Years
$27.2
$31.7
Reflects 10-year implementation phase-in of integrity tests over the period of 2016 through 2025 and costs
5 Years
$54.4
annualized over 10 years or 5 years, depending on the scenario.
Exhibit 5-6 summarizes total annualized compliance costs for this scenario, based on a 10-year
phase-in and 10-year interval for mechanical integrity testing.
Scenario (Million 2015$)1
Exhibit 5-6: Annualized Compliance Costs Relative to the Partial Industry Compliance Baseline
Cost Component
3% Discount Rate
7% Discount Rate
Mechanical integrity testing'
$27.2
$31.7
Other RP elements
$0
$0
5-7

<<<PAGE 37>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
5. Costs
Scenario (Million 2015$)'
Exhibit 5-6: Annualized Compliance Costs Relative to the Partial Industry Compliance Baseline
3% Discount Rate
7% Discount Rate
Based on 10-year phase-in of integrity tests and a 10-year interval between tests. See Exhibit 5-5 for details.
5.2.3 Regulatory Compliance Only Baseline
PHMSA used a similar approach to estimate the incremental costs relative to the worst-case baseline
scenario in which only operators of intrastate facilities located in states with existing regulations
implement the RP measures. The only difference is the number of applicable wells. In this scenario,
PHMSA subtracted from the total number of active wells only the wells at intrastate facilities in the
nine states with existing standards (see Section 4.1.1). Under these assumptions, there would be
13,682 applicable wells, out of the total of 16,991 active wells in the United States. PHMSA used the
same approach as for the partial industry compliance baseline to estimate the testing costs.
Exhibit 5-7 shows the estimated compliance costs by state, before accounting for a phase-in of the
tests (i.e., the costs in Exhibit 5-7 assume immediate implementation). Appendix B presents
estimated compliance costs by operator.
Exhibit 5-7: Incremental Integrity Testing Costs Relative to the Regulatory Compliance Only
Baseline Scenario, by State.
State
Count of Applicable Wells'
Incremental Integrity
(Million 2015$)
Testing Costs
Total Annualized Integrity
(Million 2015$/Year)
Testing Costs
Alaska
165
$16.5
$2.2
Alabama
Arkansas
13
$0.0
$0.0
$1.4
$0.2
California
Colorado
$0.0
$0.0
254
$45.7
$6.1
Illinois
224
$22.2
$3.0
Indiana
160
$15.8
$2.1
lowa
432
$42.8
$5.7
Kansas
761
$93.7
$12.5
Kentucky
337
$33.4
$4.4
Louisiana
379
$85.6
$11.4
Maryland
Michigan
2,152
84
$24.9
$3.3
$240.5
$32.0
Minnesota
66
$6.5
$0.9
Mississippi
132
$19.4
$2.6
Missouri
81
$8.0
$1.1
Montana
263
$27.1
$3.6
Nebraska
51
$8.7
$1.2
New Mexico
25
$5.1
$0.7
New York
952
$112.8
$15.0
Ohio
3,304
$406.6
$54.1
Oklahoma
329
$44.5
$5.9
Oregon
43
$4.5
$0.6
5-8

<<<PAGE 38>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
5. Costs
Exhibit 5-7: Incremental Integrity Testing Costs Relative to the Regulatory Compliance Only
Baseline Scenario, by State.
State
Count of Applicable Wells'
Incremental Integrity
Testing Costs
Total Annualized Integrity
(Million 2015$)
(Million 2015$/Year)
Testing Costs
Pennsylvania
1,670
$213.7
$28.4
Texas
115
$19.7
$2.6
Utah
63
$9.5
$1.3
Virginia
43
$7.4
$1.0
Washington
103
$10.2
$1.4
West Virginia
1,444
$175.6
$23.4
Wyoming
37
$3.8
$0.5
U.S. Total
13,682
$1,705.5
$226.9
Count of applicable wells excludes intrastate fields in states with existing requirements. See Sections 4.1.1 for
" Represents the total costs of conducting mechanical integrity tests, before accounting for the timing of the tests over
details.
the assumed 10-year phase-in period
3 Costs annualized using a 7 percent discount rate over 10 years (assuming tests conducted every 10 years.
For the primary analysis, PHMSA assumed that each well will be tested every 10 years. The costs of
implementing the integrity requirements in the RPs are approximately $194.1 million when
annualized over 10 years using a 3 percent discount and $226.9 million when annualized using a
7 percent discount. This is based on an assumed immediate implementation of the requirements.
Exhibit 5-8 summarizes the annualized costs for 10-year testing interval and an alternative 5-year
interval and assuming a 10-year phase-in period for implementing the mechanical integrity testing
program. As shown below, the estimated annualized costs of the requirements to test wells every ten
years are $170.6 million using 3 percent discount rate and $193.6 million using a 7 percent discount
rate, when phasing-in the requirements over ten years. The estimated annualized costs of testing
wells every five years are $319.7 million and $333.8 million, using 3 percent and 7 percent discount
rates respectively.
Baseline Scenario (Million 2015$)'
Exhibit 5-8: Annualized Integrity Testing Costs Relative to the Regulatory Compliance Only
Phase-in Period
Testing Interval
3% Discount Rate
7% Discount Rate
Immediate Implementation
10 Years
$194.1
$226.9
5 Years
$361.6
$388.7
Phase-in over 10 Years
10 Years
$170.6
$193.6
5 Years
$319.7
$333.8
Reflects 10-year implementation phase-in of integrity tests over the period of 2016 through 2025 and cost
nnualized over 10 years or 5 years, depending on the scenari
Exhibit 5-9 summarizes total annualized compliance costs for this scenario, based on a 10-year
phase-in and 10-year interval for mechanical integrity testing.
5-9

<<<PAGE 39>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
5. Costs
Scenario (Million 2015$)'
Exhibit 5-9: Annualized Compliance Costs Relative to the Regulatory Compliance Only Baseline
Cost Component
3% Discount Rate
Mechanical integrity testing'
$170.6
7% Discount Rate
$193.6
Other RP elements
$0.0
$0.0
Reporting
<$0.1
Total
$170.6
<$0.1
$193.6
"Based on 10-year phase-in of integrity tests and a 10-year interval between tests. See Exhibit 5-5 for details.
5.3 Economic Impacts
Mechanical integrity tests may represent a material share of storage facility operators' operation and
maintenance (O&M) expenditures and revenue. For example, one of the ten operators listed in
Exhibit 2-2, ANR Pipeline Company, reported in a FERC filing in 2015 revenue from storage
activities specifically of $121.8 million. Based on the 14 fields and 932 active wells operated by
ANR Pipeline Company, PHMSA estimated annualized testing costs of $14.9 million dollars,?3 or
12 percent of the reported revenue from these activities. As another example, PHMSA estimated
annualized testing costs for SoCalGas' 196 wells at approximately $6.7 million. Although these costs
are not attributable to the IFR given regulations proposed by the state of California and SoCalGas'
commitment to conducting the tests, they nonetheless represent approximately a quarter of the total
O&M costs the company reported in a 2014 regulatory filing requesting a rate adjustment to cover
the additional expenditures on its integrity management program (SoCalGas, 2014).
Under FERC regulation, operators of natural gas storage facilities may be able to pass through their
compliance costs to their customers through increased rates for their storage services. Under cost-of-
service ratemaking, rates are designed based on an operator's cost of providing service including an
opportunity for the operator to earn a reasonable return on its investment. Based on natural gas
storage throughput in 2015 of 3,639 BCF (amount of gas injected), the total incremental integrity
testing costs under the partial industry compliance scenario of $31.7 million (10-year phase in and
annualized over 10 years at 7 percent; see Exhibit 5-6) represent an increase of approximately
$0.01 per thousand cubic feet. This is less than 0.1 percent of the average price paid by residential
customers in the United States in 2015, assuming that all incremental storage costs are passed
through to end-use customers. Such an increase would cost the average residential customer $0.66
per year, or $0.06 per month, based on an annual average residential consumption rate of 76 thousand
cubic feet per year (EIA, 2016d).2 Under the assumption that only wells subject to state regulations
are tested in the baseline, the incremental costs of the IFR ($193.6 million annually) translate into an
increase of approximately $0.053 per thousand cubic feet, or $0.34 per month for an average
residential customer. Increase in rates paid by other types of natural gas consumer can be expected to
be similarly small. PHMSA notes that these figures may overstate impacts on average consumers,
23 Integrity testing costs are assumed to be $110,000 or $190,000 per well, based on the depth of the formation at each facility
annualized over 10 years using a discount rate of 7 percent.
operated by ANR Pipeline Company, and including economies of scale savings for fields with more than 10 wells. Costs are
24 PHMSA calculated the annual average consumption rate by dividing the total volume of natural gas delivered to residential
customers in 2014 (5.1 BCF), by the number of customers (67.2 million)
5-10

<<<PAGE 40>>>

Regulatory Impact Analysis: Underground Natural Gas Storage 5. Costs
however, since incremental storage costs affect only a fraction of the total gas consumed.25 Expressed
on the basis of total gas consumed in the United States in 2015 (27,474 BCF), the incremental costs
under the partial compliance scenario amount to approximately $0.001 per thousand cubic feet, or
less than $0.01 per month for the average residential customer.
These costs are unlikely to have a significant impact on the natural gas transmission and storage
industry, on the demand for natural gas, or on natural gas consumers.
25 According to EIA, operators injected 3,639 BCF of gas into underground storage in 2015. In that same year, total natural gas
consumption was 27,474 BCF (EIA, 2016a; 2016d)
5-11

<<<PAGE 41>>>

Regulatory Impact Analysis: Underground Natural Gas Storage 6. Benefits
6 Benefits
PHMSA expects the benefits of the IFR in general, and of the mechanical integrity testing
requirements in particular, to include the potential prevention of catastrophic natural gas releases due
to the failure of storage wells– and associated impacts on human health, property, and the
environment – or of fugitive and vented emissions ancillary to the operation of storage facilities.
This section discusses these benefits qualitatively.
6.1 Natural Gas Releases from Underground Storage
6.1.1 Catastrophic Releases
On October 23, 2015, SoCalGas’ Aliso Canyon Well SS25 developed a natural gas leak near an area
known as Porter Ranch in Los Angeles, California. Although investigations have not yet been
completed, the leak is believed to have originated from the subsurface (downhole) well casing. What
is already known, however, is that integrity assessment and monitoring were inadequate. As
documented by the Interagency Task Force on Natural Gas Storage Safety (2016), at Aliso Canyon,
“logging of SS-25 was performed only as a means to detect the presence of leaks. Since 1979, there
are no records of logs performed for the purpose of valuating the condition of the casing that could
be used to assess the risk of a leak. For example, no logs were located that could indicate metal loss
in the production casing, which is the primary barrier to the surrounding environment.”
Over the 112-day event, the accident released approximately 5.7 BCF of natural gas into the
atmosphere, containing up to 109,000 metric tons26 of methane, a potent greenhouse gas, as well as
panoply of other pollutants (California Air Resources Board (CARB), 2016a; County of Los Angeles
Public Health, 2016). Over 5,790 households had to be relocated due to the natural gas odorant
(mercaptans), according to the Aliso Canyon Incident Command briefing report issued on February
1, 2016, although some sources place the number of related households at approximately 8,000.
27
Additional reports identify other potential health effects that lasted even after the well was sealed. A
report by the Los Angeles County of Public Health suggests that the continued health symptoms may
be due to contaminants in indoor air and dust (Los Angeles County Public Health, 2016). As of
November 2, 2016, Sempra Energy, the parent company of SoCalGas, reported costs of $763 million
to control the release, monitor air emissions, relocate residents, and cover its legal and other expenses
(Sempra, 2016).
28 These costs are those incurred by Sempra and do not include additional costs to
society as a result of the release.
26 CARB estimates that the incident resulted in a total emission of 99,650 ± 9,300 metric tons of methane (CARB, 2016a) and
seeks mitigation of 109,000 metric tons.
27 For example, see KPCC news report on August 4, 2016, “Cost estimate of Aliso Canyon gas leak hits $717 million”.
http://www.scpr.org/news/2016/08/04/63268/cost-estimate-of-aliso-canyon-gas-leak-hits-717-mi/
28 Of the $763 million, Sempra Energy notes “approximately 70% is for the temporary relocation program (including cleaning
costs and certain labor costs) and approximately 20% is for efforts to control the well, stop the leak, stop or reduce emissions, and
the estimated cost of the root cause investigation. The remaining amount includes legal costs incurred to defend litigation, the
value of lost gas, the costs to mitigate the actual natural gas released and other costs. Cost estimate excludes any potential
damage awards, restitution and any civil, administrative or criminal fines and other penalties that may be imposed, as well as any
6-1

<<<PAGE 42>>>

Regulatory Impact Analysis: Underground Natural Gas Storage 6. Benefits
Several other catastrophic incidents involving natural gas underground storage facilities have
occurred in the past 15 years (Hopper, 2004; British Geological Survey, 2008; Kansas Geological
Survey, 2004):29
 On August 19, 2004, the Market Hub Partners Moss Bluff storage facility located in Liberty
County, Texas, had a well control incident and natural gas fire at Cavern #1. According to
newspaper reports at the time, the incident sent a plume of burning gas “hundreds of feet into
the air” (Bardwell and Horswell, 2004) and forced the evacuations of residents within a
three-mile radius (OGJ, 2004). Over a period of 6.5 days, the incident released and burned
approximately 6 BCF of gas. Estimates of the number of people evacuated vary between
dozens and hundreds. Hopper (2004) estimated the value of the product lost at $36 million
and property damage at $20 million. Investigators attributed the incident to initial separation
and breach of a 8-5/8-inch well string inside the cavern.
 A casing failure at the Magnolia Salt Cavern facility in December 2003 caused the release of
approximately 0.35 BCF of natural gas, forced the shutdown of the facility and the
evacuation of area residents (approximately 30 people). Geologists determined that the
eruptions had sprung from an underground gas storage field seven miles away and migrated
into injection wells. Investigator attributed the incident to casing failure, specifically to a
crack in the casing of a well near the top of a cavern.
 On January 17 and 18, 2001, the Yaggy underground natural gas storage field operated by
Kansas Gas Service had a wellbore failure, which led to a series of gas explosions in
Hutchinson, Kansas. The gas leaked from the storage field well production casing and
migrated approximately nine miles underground to the Hutchinson, Kansas area. An
explosion in downtown Hutchinson destroyed two businesses, damaged 26 others, and
caused two fatalities. Approximately 250 people were evacuated. Approximately 143 million
cubic feet of natural gas leaked from the storage field. Flares took over a month to burn off
the escaped gas.30 Investigators attributed the incident to a hole in the well casing. Although
PHMA could not find response costs for this incident, other costs incurred by the responsible
party included payment of $1.7 million to the two businesses destroyed by the explosions, $5
million in court-awarded damages to residential plaintiffs for impacts on housing prices due
to “stigma” effects of the release, and a $180,000 fine assessed by the Kansas Department of
Health and Environment.
Although infrequent, catastrophic natural gas release incidents can cause significant damages due to
the quantities of natural gas involved, proximity to populations, and other factors. Note that in recent
accidents, natural gas migrated underground for miles before erupting in locations distant from the
source of the leak. The difficulty of identifying the actual dimensions of elevated risk zones argues in
favor of making an additional effort to identify possible sources and prevent leaks in the first place.
additional costs to clean homes and future legal costs necessary to defend litigation, among other potential costs, as we cannot
estimate what amounts, if any, will be incurred for such matter.” (Sempra Energy, 2016).
29 There have also been additional accidents involving underground storage facilities storing other products such as liquefied
petroleum gas (LPG).
30 Flares are commonly used as a means of disposing of waste gas, when it is safer to burn the gas than to simply vent it to the
atmosphere.
6-2

<<<PAGE 43>>>

Regulatory Impact Analysis: Underground Natural Gas Storage 6. Benefits
The benefits of preventing accidental natural gas releases include avoided property damages, injuries
and fatalities, resident relocation, adverse human health effects, and emissions of methane (CH4), the
main constituent of natural gas and a potent greenhouse gas.
6.1.2 Operational Releases
Operational releases of natural gas from storage facilities include fugitive emissions (70 percent) and
vented natural gas (30 percent). Equipment leak is the principal source of fugitive emissions (U.S.
EPA, 2008). The leaks may be caused by mechanical and thermal stresses in piping, valves,
compressor seals, flanges, fittings, and other components. They may also arise due to improperly
plugged and abandoned wells (and to a lesser extent from the geologic formation due to over-
pressurizing). Venting is associated with various equipment or operations (e.g., compressor
startup/shutdown), condensate storage tank vents, equipment depressurization.
The annual Inventory of U.S. Greenhouse Gas Emissions and Sinks (GHG Inventory) provides
estimates of fugitive natural gas methane emissions from transmission and storage segments of the
natural gas industry (EPA, 2016a; 2016b). In the GHG Inventory, wells at approximately 400
underground storage facilities released approximately 15.7 kt CH4 in 2014, or 114.5 standard cubic
feet per day per well.
31 For comparison, total methane emissions from natural gas transmission and
storage were 1,282 kt CH4 in 2014.
A 2015 study of sources of methane emissions from transmission and storage by the Joint Institute
for Strategic Energy Analysis (JISEA) highlighted approaches for reducing operational releases that
include periodic leak detection and repairs and improvements in the construction and operation of the
wells and reservoirs. The implementation of mechanical integrity tests and other measures contained
in the API RPs referenced in the IFR represent steps in reducing these emissions.
6.2 Benefits of the IFR
As described in Section 6.1, casing defects and failures caused the releases at the Magnolia Salt
Cavern and Yaggy Field, and preliminary reports point to casing failure as the cause of the Aliso
Canyon incident as well. Mechanical integrity tests and other measures mandated by the IFR are
expected to reduce the likelihood of such well failures in the future by detecting conditions that
precede the failures. PHMSA did not find data to estimate quantitatively the reduction in risk that
will result from conducting mechanical integrity tests on storage wells but notes that the tests are
used to establish existing conditions and to monitor development of corrosion or other conditions
(e.g., mechanical defects or damages) that could lead to a release or other consequences. However,
PHMSA requests any information from the public that could be used to estimate such risk reduction.
Corrosion poses a serious threat to maintaining natural gas containment. Without proactive tests,
serious integrity conditions may be discovered and addressed only after containment has already
been compromised and the casing is leaking. SoCalGas (2014) noted an increase in the number of
safety and integrity conditions discovered during well repair work, including casing or tubing leaks.
Ultrasonic surveys SoCalGas conducted between 2008 and 2013 as part of well repair work revealed
internal or external casing corrosion or mechanical damage in 15 wells (SoCalGas, 2014; p. PEB-9).
31 Storage well CH4 emissions from Table A-147 in U.S. EPA (2016b). 1 kt = 1 kilotonne = 1 Gg.
6-3

<<<PAGE 44>>>

Regulatory Impact Analysis: Underground Natural Gas Storage 6. Benefits
These are the types of conditions that led to the failures described in in Section 6.1 and which
mechanical integrity tests are designed to detect.
By requiring natural gas storage facility operators to implement measures to detect and address well
integrity issues preventively, implementation of the IFR may help reduce overall storage operating
costs, particularly when accounting for the much greater costs of reactive measures. In fact,
SoCalGas explicitly mentions the greater cost of reactive measures taken after a leak has occurred as
justification for its proposed storage integrity management program (SIMP), noting that “without the
SIMP, SoCalGas will continue to operate in a reactive mode (with the potential for even higher costs
to ratepayers) to address sudden failure of old equipment. In addition, SoCalGas and customers could
experience major failures and service interruptions from potential hazards that currently remain
undetected.” (SoCalGas, 2014)
This greater cost is apparent when considering the response to the Aliso Canyon incident, which
required drilling relief wells to intercept and seal the leaking well. SoCalGas reported capital costs
for well control, leak stoppage and relief wells of $53.4 million through February 2016 (not counting
other costs such as those associated with residents relocation, air emissions monitoring, public
relations, etc.; SoCalGas, 2016b). SoCalGas ultimately succeeded in stopping the leak by plugging
the failed well. Although a detailed breakdown and assessment of the costs of response actions is not
available, the magnitude of these costs may be driven in part by the emergency conditions under
which these actions had to be taken, as they are significantly higher than the capital costs for
maintaining, replacing, and plugging wells under normal operating conditions. For example, in its
O&M forecast to the California Public Utilities Commission, SoCalGas had estimated the cost of
replacing well tubing at $575,000 per well, making repairs for leaking wellheads at $450,000 per
well, drilling replacement wells at $5 million to $6 million per well, and plugging wells at $600,000
per well (in 2013 dollars; SoCalGas, 2014).
Beyond lower operating costs, other benefits of preventing natural gas releases include those
associated with avoided loss of product, property damage, injuries and fatalities, emissions of
methane, adverse health effects, and others.
Descriptions of the catastrophic incidents in Section 6.1.1 provide a tally of the costs incurred by
natural gas operators (as reported in public records), but represent an incomplete accounting of the
social costs of natural gas releases resulting from storage well failures. For example, missing from
the tally are long-term damages resulting from the methane emissions.
Methane is a potent greenhouse gas (GHG) with a climate forcing effect that is 28-36 times greater
than that of carbon dioxide over a 100-year period (Intergovernmental Panel on Climate Change
(IPCC), 2013). The Interagency Working Group on the Social Cost of Greenhouse Gases
(IWGSCGG) estimated the global social costs of climate damages associated with an incremental ton
of methane emissions by year for different discount rates (IWGSCGG, 2016). Using the values
published by IWGSCGG (see Exhibit 6-1), PHMSA estimated the social costs of the climate-related
impacts of the Aliso Canyon incident at $122.9 million dollars, based on the release of up to 109,000
6-4

<<<PAGE 45>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
6. Benefits
metric tons of methane and the average SC-CH4 at a 3 percent discount rate. Social cost estimates
range from $55.3 to $344.2 million, depending on the discount rate. Using the same approach, the
climate change impacts from operational releases from fugitive and venting emissions (15,700 metric
tons per year; see Section 6.1.2) are estimated at approximately $1.8 million as of 2015 at a 3 percent
discount rate, with a range of $0.8 to $5.0 million. Exhibit 6-2 summarizes the value of estimated
impacts of methane emissions at various discount rates. If an inspection allows an operator to correct
and reduce fugitive emissions, then the benefits of the inspection would be realized for several years
since these emissions are ongoing.
Exhibit 6-1: Social Cost of Methane??
20075 per Metric T8% CH.
2015$ per Metric Ton CHA
Average
percentile
Average
Average
percentile
3% 95th
$3,158
$3,609
$4,173
$4,737
$5,526
$6,203
$6,879
'Source: Values from Table 1 in IWGSCGG (2016). Social Cost of Methane (SC-CH4), 2010 - 2050
$7,556
2 PHMSA restated costs to 2015 dollars using the GDP deflator (GDP 2015/GDP 2007 = 1.1278)
Exhibit 6-2: Climate Change-related Impacts of Methane Emissions from Natural Gas Storage
Wells
Release Source
Basis
Methane
Value of Damages (Million 20155)
(Metric Tons)
Quantity
5% Average
3% Average
2.5%
3% 95''
Aliso Canyon incident
One-time
109,000
$55.3
$122.9
Average
percentile
$172.1
$344.2
Fugitive emissions
Annual
15,700
$0.8
$1.8
$2.5
$5.0
"Calculated as the quantity (in metric tons) times the SC-CH4 values for 2015 in Exhibit 6-1.
In summary, to the degree that the IF promotes implementation of safer practices by making them
mandatory and enforceable, then the FR has the potential to provide the benefits described in this
section by acting on information obtainable through inspections to reduce the probability of
catastrophic or operational natural gas releases or their magnitude 33 PHMSA seeks comment and
data on how these expected benefits might be quantified.
32
discount rate, emissions occurring in 2015). Costs were restated from 2012 dollars to 2015 dollars using the GDP deflator
Based on emissions of 109,000 metric tons of methane and a cost of $1,128 per metric ton (average SC-CH4 at a 3%
($1,100 × 1.04335)
33 If storage facility operators currently conduct mechanical integrity tests and implement other measures contained in the API
reflected in the baseline and are not attributable to the IFR
RPs or will do so without being compelled by regulations, then the associated prevention benefits (and the costs) are already
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Regulatory Impact Analysis: Underground Natural Gas Storage 6. Benefits
The IFR also provides hard-to-quantify benefits from increasing certainty by specifying mandatory
minimum safety standards that all operators must meet.
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Regulatory Impact Analysis: Underground Natural Gas Storage 7. Uncertainty and Limitations
7 Uncertainty and Limitations
The sections below discuss main areas of uncertainty and limitations of the analysis.
7.1 Affected Facilities and Operators
As discussed in Section 2, PHMSA identified a total of 390 active fields operated by 124 companies.
PHMSA identified a total of 16,991 active wells at these fields. Data on the number of wells were
obtained primarily from a survey published by AGA (2014) that reflects fields in operation in
2013/2014. The AGA report lists additional fields, however, that are not contained in the EIA data
set. Conversely, the EIA data include fields not contained in the AGA report. Fields in Alaska were
omitted entirely from the AGA report and PHMSA estimated the number of wells that may be
present in those fields based on the ratio of the number of well and storage capacity in Lower-48
fields. The actual number of wells in Alaska may be higher or lower than that estimated by PHMSA.
PHMSA did not estimate the number of wells in other fields reported in EIA but omitted from the
AGA report (26 fields of the 390 total fields reported by EIA). Omission of these wells may
understate costs.
Overall, PHMSA expects the uncertainty on the exact number of fields and wells to have a small
effect on the estimated costs since PHMSA estimates are generally close to those available from
other sources, including industry estimates. Thus, as of June 1, 2016, AGA estimated at 397 the
number of active fields in the Lower-48 states, as compared to PHMSA’s estimate of 385. AGA
estimated at 16,900 the number of wells in those fields, as compared to PHMSA’s 16,826 (AGA,
Personal Communication) 34, a difference of only about 0.4 percent.
PHMSA used a static snapshot of storage fields and wells in estimating the incremental costs of the
IFR. As discussed in Section 4.2.4, however, historical data show a 16 percent increase in
underground storage capacity between 1995 and 2014 (EIA, 2016b). If this growth trend were to
continue and additional wells were constructed and subject to mechanical integrity test, then
assuming that the number of wells remains constant understates the costs of the IFR. PHMSA
doesn’t have data on changes in the number of wells over time and notes that the existing relationship
between gas working capacity and the number of wells is not linear. Nonetheless, if we assume that
storage capacity will continue to increase at the same rate as the last two decades (16 percent over
20 years, or 0.75 percent per year) and further assume that the number of wells will increase in
proportion to the storage capacity, then annualized testing costs may be $32.8 million as compared to
$31.7 million for the static scenario (see Exhibit 5-5; 7 percent discount rate and 10-year phase-in
and testing interval). Note that this alternate calculation overstates the cost of the IFR since it
assumes that new wells will be inspected as they become active whereas operators may not test wells
until years later according to their risk-based integrity management program.
34 Email from Cristina Sames of AGA to Alan Mayberry of PHMSA dated June 1, 2016.
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Regulatory Impact Analysis: Underground Natural Gas Storage 7. Uncertainty and Limitations
7.2 Baseline Degree of Compliance
PHMSA’s analysis of the costs and benefits of the RFI depends on assumptions about the actions
storage facility operators will take to implement the API RPs. The most significant area of
uncertainty is the degree to which operators of underground natural gas storage facilities would be
implementing the API RPs in the absence of regulatory requirements. As discussed in Section 4.1.2,
industry representatives stated the commitment by natural gas storage operators to implement the
API RPs in full, described existing compliance with some elements of the RPs, and outlined the
schedule for implementing the remaining substantive measures in the RPs. Specifically, input from
INGAA (2016) describes that operators have already been implementing many of the practices
contained in the API RPs and are already assessing their existing risk management plans and other
measures to verify adherence to the API RPs. For example, INGAA notes that “operators have
individually developed and maintained well and reservoir integrity management programs” but that
the standards now provide a way for operators to “align their integrity programs and measure
continual integrity management improvements.” INGAA provides other examples of current
activities undertaken by operators, including monitoring for the presence of annular gas and
monitoring the injection and withdrawal flow rates and pressures at each storage reservoir; annual or
more frequent visits and observation of the well assembly and conditions; and annual testing of
existing surface and subsurface shut-off valve systems per manufacturer’s recommendations and
operator procedures (INGAA, 2016).INGAA members have started conducting the tests needed to
meet the schedule outlined by INGAA which set out to evaluate 50 percent of their active wells
within two years and the remainder within five years, and to complete all of the activities in
approximately seven to eight years. INGAA member companies operate 86 percent of all active wells
in the United States.
Because of the uncertainty regarding the level of implementation of the API RPs in the absence of a
rule, PHMSA conducted its analysis relative to three baselines (see Section 4.1.3): a baseline that
assumes industry-wide implementation of the RP, an alternative baseline with implementation
limited to certain operators or types of fields, and a worst-case baseline (from the perspective of IFR
incremental costs) that assumes that only operators of intrastate facilities in states with regulatory
requirements would implement the RP absent federal regulations. PHMSA expects actual baseline
conditions to lie between full compliance, with annualized costs attributable to the IFR being less
than $0.1 million, and partial compliance, with annualized costs of $31.7 million (7 percent discount
rate and 10-year phase-in and testing interval).
The benefits of the IFR also depend on the baseline level of implementation. If storage facility
operators currently conduct mechanical integrity tests and implement other measures contained in the
API RPs or will do so without being compelled by regulations, then the associated prevention
benefits (see Section 6.2) are already reflected in the baseline and are not attributable to the IFR.
7.3 Mechanical Integrity Testing Costs
The analysis uses average costs of conducting mechanical integrity tests on wells within three depth
ranges. As discussed in Section 5.1.1, actual costs may vary depending on the location, well
characteristics and other factors. For example, the inspection may run into unforeseen difficulties
during test preparation or performance, which may increase the cost of conducting the tests.
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Regulatory Impact Analysis: Underground Natural Gas Storage 7. Uncertainty and Limitations
PHMSA assumed that testing costs include analysis of the results to determine follow up actions,
such as the timing of subsequent inspections.
PHMSA assumed that testing costs would be less in cases where a field has more than 10 wells.
Removing this assumption increases the annualized testing costs to $34.9 million (7 percent discount
rate and 10-year phase-in and testing interval) as compared to $31.7 million (Exhibit 5-4).
PHMSA used the maximum depth of each field formation, based on data from AGA (2014). This
assumption provides an upper bound for testing costs within a field. If wells are shallower than
assumed by PHMSA, the IFR costs will be lower. For example, using the midpoint of the formation
depth range as the basis for testing cost shows 18 active fields that correspond to a less expensive
testing cost category and total annualized costs of $31.6 million, as compared to $31.7 million using
the maximum formation depth (Exhibit 5-4).
7.4 Timing of Compliance Activities
The analysis assumes that implementation will be phased-in over 10 years, but starting immediately
(in 2016). This immediate start overstates costs slightly relative to implementation starting at a future
date to be specified 12 months from the effective date of the rule.
For the analysis, PHMSA assumed a uniform interval of 10 years (or alternative interval of 5 years)
between successive integrity tests on a well. PHMSA analyzed the two intervals as illustrative of the
potential programs operators may develop. In practice, however, the interval between successive tests
will be determined based on a field-specific (and perhaps well-specific) assessment of the risk as
described in the API RPs. If this risk-based interval is less than 5 years then the annualized costs
would be greater than estimated by PHMSA for the most stringent alternative scenario analyzed.
7.5 Effectiveness of RPs to Prevent Future Incidents
As discussed in Section 6.2, benefits of the IFR are difficult to quantify. Incidents involving the
catastrophic release of natural gas from underground storage facilities are very infrequent. The
contribution of integrity tests to preventing or reducing the impacts of a release is unknown. The risk
of an accident may change over time as use of the fields increase and wells and other surface
equipment age.
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Regulatory Impact Analysis: Underground Natural Gas Storage 8. Other Analyses
8 Analyses Required under Applicable Statutes or Executive
Orders
PHMSA must conduct analyses of the costs, benefits, and economic impacts of the regulation to
fulfill requirements of various statutes and Executive Orders. As discussed in Section 4.1.2,
information received from industry representatives indicate that storage facility operators already
implement the API RPs or have committed to do so even in the absence of the IFR. This section
discusses the IFR in the context of each of the Statutory or Executive Orders requirements relative to
the partial compliance and full compliance baseline scenarios.
8.1 Executive Orders 12866 and 13563: Analysis of Costs and Benefits
Under Executive Order 12866 (58 FR 51735, October 4, 1993), PHMSA must determine whether the
regulatory action is “significant” and therefore subject to review by the Office of Management and
Budget (OMB) and other requirements of the Executive Order. The order defines a “significant
regulatory action” as one that is likely to result in a regulation that may:
 Have an annual effect on the economy of $100 million or more, or adversely affect in a
material way the economy, a sector of the economy, productivity, competition, jobs, the
environment, public health or safety, or State, local, or Tribal governments or communities;
or
 Create a serious inconsistency or otherwise interfere with an action taken or planned by
another agency; or
 Materially alter the budgetary impact of entitlements, grants, user fees, or loan programs or
the rights and obligations of recipients thereof; or
 Raise novel legal or policy issues arising out of legal mandates, the President’s priorities, or
the principles set forth in the Executive Order.
Executive Order 13563 (76 FR 3821, January 21, 2011) supplements Executive Order 12866 by
outlining the President’s regulatory strategy to support continued economic growth and job creation,
while protecting the safety, health and rights of all Americans. Executive Order 13563 requires
considering costs, reducing burdens on businesses and consumers, expanding opportunities for public
involvement, designing flexible approaches, ensuring that sound science forms the basis of decisions,
and retrospectively reviewing existing regulations.
Pursuant to the terms of Executive Order 12866, PHMSA determined that the regulation is not an
“economically significant regulatory action” because, under the most reasonable baselines in which a
significant fraction of the industry is already implementing the required provisions, it is unlikely to
have an annual effect on the economy of $100 million or more. Although the annualized compliance
costs relative to the regulatory compliance only baseline are greater than $100 million
($170.6 million at a 3 percent discount and $193.6 million at a 7 percent discount), PHMSA notes
that information provided by the industry suggests that using this baseline would greatly overstate the
impacts of the IFR.
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Regulatory Impact Analysis: Underground Natural Gas Storage 8. Other Analyses
Although PHMSA determined that the IFR is not economically significant, the Agency nonetheless
submitted this action for review by the Office of Management and Budget (OMB) under Executive
Orders 12866 and 13563. The docket for this action documents changes made in response to OMB
suggestions or recommendations.
8.2 Regulatory Flexibility Act (RFA)
The Regulatory Flexibility Act (RFA) of 1980, as amended by the Small Business Regulatory
Enforcement Fairness Act (SBREFA) of 1996, requires Federal agencies to consider the impact of
their rules on small entities, analyze alternatives that minimize those impacts, and make their
analyses available for public comments. The Act is concerned with three types of small entities:
small businesses, small nonprofits, and small government jurisdictions.
The RFA describes the regulatory flexibility analyses and procedures that Federal agencies must
complete unless they certify that the rule, if promulgated, would not have a significant economic
impact on a substantial number of small entities. A statement of factual basis must support this
certification, e.g., through addressing the number of small entities affected by the proposed action,
calculating expected cost impacts on these entities, and evaluating economic impacts.
PHMSA prepared a RFA screening analysis of this IFR, which is summarized below. Based on this
analysis, PHMSA determined that the IFR will not have “a significant impact on a substantial
number of small entities” (No SISNOSE).
8.2.1 Identifying Small Entities
The RFA incorporates and uses the definition of "small business" found in the Small Business Act (5
U.S.C. section 601(3)). The Small Business Act authorizes the Small Business Administration (SBA)
to define "small business" by issuing regulations. SBA periodically reviews and reissues these
definitions. SBA (2016) has established size standards for various types of economic activities, or
industries, under the North American Industry Classification System (NAICS). These size standards
generally define small businesses based on the number of employees or annual receipts. For example,
Exhibit 8-1 shows the SBA size standards for pipeline transportation (NAICS 486). Underground
storage of natural gas is covered under NAICS 486210: Pipeline Transportation of Natural Gas.
35
Note that the SBA definition of a small business applies to a firm's parent company and all affiliates
as a single entity. The business size is determined based on the primary economic sector of the parent
company, which is not necessarily pipeline transportation of natural gas.
35 486 PIPELINE TRANSPORTATION: Industries in the Pipeline Transportation subsector use transmission pipelines to
transport products, such as crude oil, natural gas, refined petroleum products, and slurry. Industries are identified based on the
products transported (i.e., pipeline transportation of crude oil, natural gas, refined petroleum products, and other products). The
Pipeline Transportation of Natural Gas industry includes the storage of natural gas because the storage is usually done by the
pipeline establishment and because a pipeline is inherently a network in which all the nodes are interdependent. (U.S. Census,
2012)
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Regulatory Impact Analysis: Underground Natural Gas Storage 8. Other Analyses
Exhibit 8-1: Small Business Size Standards: Subsector 486 – Pipeline Transportation
NAICS Code Description Standard
486110 Pipeline Transportation of Crude Oil 1,500 employees
486210 Pipeline Transportation of Natural Gas $27.5 million
486910 Pipeline Transportation of Refined Petroleum Products 1,500 employees
486990 All Other Pipeline Transportation $37.5 million
Source: SBA (2016)
NAICS = North American Industrial Classification System
SBA = Small Business Administration
The RFA defines "small governmental jurisdiction" as the government of a city, county, town,
township, village, school district, or special district with a population of less than 50,000 (5 U.S.C.
section 601(5)). For the purposes of the RFA, states and tribal governments are not considered small
governments.
The RFA defines "small organization" as any "not-for-profit enterprise which is independently
owned and operated and is not dominant in its field".
36 PHMSA did not identify small organizations
affected by the final rule.
8.2.2 Small Businesses Affected by the Final Rule
To identify small businesses, PHMSA used operator data from EIA (2016e) and related the data to
existing information available to PHMSA for natural gas pipeline operators that submitted 2014
Annual Reports. PHMSA had already combined the 2014 Annual Reports filers with data provided
by Dun & Bradstreet (D&B) that included determination of small business classification.37 Note that
the D&B classification may be based on a different primary industrial classification than pipeline
transportation of natural gas in cases where the parent entity’s primary business is in another
economic sector.
PHMSA conducted selective additional review of other data sources to complement, confirm or
update the D&B size classification. PHMSA determined the size category for 48 of the 124 operators
of underground storage facilities for which PHMSA did not have a size determination from D&B.
PHMSA determined the size for these operators based on data from other publically available
sources (company websites, Security and Exchange Commission (SEC) filings, Manta.com, etc.).
PHMSA also used data from these other sources to verify, and as needed update, the parent entity
information and the size determination derived from D&B data.
Thus, of the four small business entities identified by PHMSA, two businesses were identified based
on revenue below the $27.5 million threshold defined by SBA for NAICS 486210 (Egyptian Gas
36 5 U.S.C. section 601(4)
37 The D&B data set corresponds to the operators who filed annual reports for the calendar year 2014 and which PHMSA
analyzed in its Preliminary Regulatory Impact Assessment for the Notice of Proposed Rulemaking - Pipeline Safety: Safety of
Gas Transmission and Gathering Pipelines (PHMSA, 2016a). PHMSA compared this list to the 124 operators of active natural
gas underground storage facilities identified by EIA.
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Regulatory Impact Analysis: Underground Natural Gas Storage 8. Other Analyses
Storage Corporation and Honeoye Storage Corporation), one had no revenue data38 and was assumed
to be small (Cherokee Wells LLC), and the last entity was determined to be small based on
population (City of Elizabethtown).
Exhibit 8-2 summarizes the number of entities in each size category. Note that some operators are
owned by the same domestic parent entity and therefore there are fewer than 124 unique parent
entities represented in the data.
Exhibit 8-2: Size of Natural Gas Underground Storage Operating
Entities Affected by the IFR
Size Category Number
Small1 4
Large 120
Total 124
1. Based on information from Dun & Bradstreet, supplemented by PHMSA.
8.2.3 Impacts of the IFR on Small Entities
PHMSA estimated that four small entities will have to comply with IFR requirements: three private
entities and one small municipal government entity (City of Elizabethtown, KY).
For this screening analysis, PHMSA looked at the impacts from both the partial compliance and full
compliance baseline scenarios. As discussed in Section 5.2, under the scenario where storage facility
operators already implement the API RPs in the baseline, the only compliance costs attributable to
the IFR are those associated with reporting requirements. These costs, which are detailed in Section
5.1.4, are approximately $79,600 per year across all 124 operators (using a 7 percent discount rate).
Under the alternative scenario wherein a small fraction of operators would not implement the API
RPs without being compelled by the IFR, compliance costs attributable to the regulation also include
the costs of conducting mechanical integrity tests, detailed in Section 5.1.1. If the analysis suggests
minimal impacts under the second, partial industry compliance baseline scenario, then PHMSA may
conclude no SISNOSE irrespective of uncertainty about the baseline level of compliance with API
RPs by small entities.
PHMSA used a sales test to estimate the economic impact of the compliance costs for small storage
facility operators. This test consists of dividing total annual compliance costs by annual receipts. If
this ratio is high for many small entities then the agency may not be able to certify that the rule will
not have a significant economic impact on a substantial number of small entities. If a rule does have a
Significant Impact on a Substantial Number of Small Entities (SISNOSE) then under the RFA,
PHMSA would have to prepare a Final Regulatory Flexibility Analysis. PHMSA uses cost to revenue
ratios of 1 percent and 3 percent of revenue. PHMSA then evaluated the absolute number and the
percent of entities in each impact category, and by type of ownership. The Agency assumed that
entities incurring costs below 1 percent of revenue are unlikely to face significant economic impacts,
while entities with costs of at least 1 percent of revenue have a higher chance of facing significant
38 PHMSA could not find sales data for five operators from D&B or other publically available sources. For four of these
operators, further research revealed a subsidiary relationship to a large company. PHMSA assumed that the remaining operator is
small.
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Regulatory Impact Analysis: Underground Natural Gas Storage 8. Other Analyses
economic impacts, and entities incurring costs of at least 3 percent of revenue have a still higher
probability of significant economic impacts.
For revenue data, PHMSA primarily relied on firm level data obtained from D&B for 2015 and on
data obtained from other sources for the most recent year available. PHMSA adjusted revenue to
2015 dollars. PHMSA calculated annual compliance costs per operator as described in Section 5.
Exhibit 8-3 summarizes the results of the screening analysis. None of the small businesses affected
by the regulation are expected to have costs exceeding 1 percent of sales under any of the three
baseline scenarios PHMSA analyzed. This is because all four small businesses operate intrastate
fields in states (Illinois, Kansas, and New York) that already have regulatory requirements in the
baseline. Accordingly, incremental costs for these businesses arise only from the requirement to
submit an Annual Report and incident or safety-related conditions reports as needed. The total costs,
if all three types of report are needed in the same year, are approximately $1,500. Although entity
revenue data are not available for two of the entities, PHMSA expects that the costs are de minimis
relative to revenue for all four small businesses. These results support a determination that the IFR
will not have “a significant impact on a substantial number of small entities” (No SISNOSE).
Exhibit 8-3: Summary of Economic Impact Screening Analysis
Partial Industry
Compliance Baseline
Category Full Industry
Compliance Baseline
Total small entities affected 4 4
Number (%) small entities for which compliance costs may
exceed 1% of sales 0 (0%) 0 (0%)
Number (%) small entities for which compliance costs may
exceed 3% of sales 0 (0%) 0 (0%)
8.3 Unfunded Mandates Reform Act (UMRA) Analysis
Title II of the Unfunded Mandates Reform Act (UMRA) of 1995, Pub. L. 104-4, requires that
Federal agencies assess the effects of their regulatory actions on State, local, and Tribal governments
and the private sector. Under UMRA section 202, PHMSA generally must prepare a written
statement, including a cost-benefit analysis, for proposed and final rules with “Federal mandates”
that might result in expenditures by State, local, and Tribal governments, in the aggregate, or by the
private sector, of $100 million (adjusted annually for inflation) or more in any one year (i.e.,
$151 million in 2015 dollars).
Based on the cost estimates detailed in Section 5, PHMSA estimated the compliance costs to be
below the threshold set in UMRA.
8.4 Executive Order 13132: Federalism
Executive Order 13132 (64 FR 43255, August 10, 1999) requires PHMSA to develop an accountable
process to ensure “meaningful and timely input by State and local officials in the development of
regulatory policies that have federalism implications.” Policies that have federalism implications are
defined in the Executive Order to include regulations that have “substantial direct effects on the
States, on the relationship between the national government and the States, or on the distribution of
power and responsibilities among the various levels of government.”
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Regulatory Impact Analysis: Underground Natural Gas Storage 8. Other Analyses
Under section 6 of Executive Order 13132, PHMSA may not issue a regulation that has federalism
implications, that imposes substantial direct compliance costs, and that is not required by statute
unless the Federal government provides the funds necessary to pay the direct compliance costs
incurred by State and local governments or unless PHMSA consults with State and local officials
early in the process of developing the regulation. PHMSA also may not issue a regulation that has
federalism implications and that preempts State law, unless the Agency consults with State and local
officials early in the process of developing the regulation.
PHMSA has concluded that this action will not have federalism implications, because it does not
impose substantial direct compliance costs on State or local governments.
PHMSA identified one local government entity (City of Elizabethtown) that operates an active field
affected by the IFR but this intrastate field is located in a state with existing regulatory requirements
(Kansas) and therefore incremental costs due to the IFR consist of only very small (non-substantial)
reporting costs.
8.5 Executive Order 13211: Actions Concerning Regulations That Significantly
Affect Energy Supply, Distribution, or Use
Executive Order 13211 requires Agencies to prepare a Statement of Energy Effects when
undertaking certain agency actions. Such Statements of Energy Effects shall describe the effects of
certain regulatory actions on energy supply, distribution, or use, notably: (i) any adverse effects on
energy supply, distribution, or use (including a shortfall in supply, price increases, and increased use
of foreign supplies) should the proposal be implemented, and (ii) reasonable alternatives to the action
with adverse energy effects and the expected effects of such alternatives on energy supply,
distribution, and use.
The OMB implementation memorandum for Executive Order 13211 outlines specific criteria for
assessing whether a regulation constitutes a “significant energy action” and would have a “significant
adverse effect on the supply, distribution or use of energy.” 39 Those criteria include:
1. Reductions in crude oil supply in excess of 10,000 barrels per day;
2. Reductions in fuel production in excess of 4,000 barrels per day;
3. Reductions in coal production in excess of 5 million tons per year;
4. Reductions in natural gas production in excess of 25 million mcf per year;
5. Reductions in electricity production in excess of 1 billion kilowatt-hours per year, or in excess of
500 megawatts of installed capacity;
6. Increases in the cost of energy production in excess of 1 percent;
7. Increases in the cost of energy distribution in excess of 1 percent;
8. Significant increases in dependence on foreign supplies of energy; or
9. Having other similar adverse outcomes, particularly unintended ones.
Of the potential significant adverse effects on the supply, distribution, or use of energy (listed above),
only the seventh is relevant to the IFR. Though the IFR could increase the cost of transporting natural
39 Executive Order 13211 was issued May 18, 2002. The Office of Management and Budget later released an
Implementation Guidance memorandum on July 13, 2002.
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Regulatory Impact Analysis: Underground Natural Gas Storage 8. Other Analyses
gas, the cost increase is expected to less than the 1 percent threshold suggestive of potential impacts
on energy supply, distribution, or use.
As detailed in Section 5.2.3, the compliance costs under the partial compliance scenario amount to
approximately $0.009 per thousand cubic feet, which is less than 0.1 percent of natural gas rates paid
by residential consumers. For the worst-case regulatory compliance only baseline scenario, the
incremental costs translate in approximately $0.053 per thousand cubic feet, which is approximately
0.4 percent of the residential rates. According to AGA (2015), the cost of the gas itself accounts for
approximately 41 percent of the revenue received by a distribution company, meaning that the
remaining 59 percent covers fixed and variable costs of transporting and distributing natural gas to
consumers. Based on this share, PHMSA determined that the impacts on transportation and
distribution costs are below the 1 percent threshold. This is true for all scenarios PHMSA analyzed.
The compliance costs for the partial compliance scenario represent approximately 0.14 percent of
transportation and distribution costs, whereas compliance costs for the worst-case regulatory
compliance only baseline scenario represent 0.87 percent of transportation and distribution costs.
8.6 Paperwork Reduction Act of 1995
The Paperwork Reduction Act of 1995 (PRA) (superseding the PRA of 1980) is implemented by the
Office of Management and Budget (OMB) and requires that agencies submit a supporting statement
to OMB for any information collection that solicits the same data from more than nine parties. The
PRA seeks to ensure that Federal agencies balance their need to collect information with the
paperwork burden imposed on the public by the collection.
The definition of “information collection” includes activities required by regulations, such as permit
development, monitoring, record keeping, and reporting. The term “burden” refers to the “time,
effort, or financial resources” the public expends to provide information to or for a Federal agency,
or to otherwise fulfill statutory or regulatory requirements. PRA paperwork burden is measured in
terms of annual time and financial resources the public devotes to meet one-time and recurring
information requests (44 U.S.C. 3502(2); 5 C.F.R. 1320.3(b)). Information collection activities may
include:
 reviewing instructions;
 using technology to collect, process, and disclose information;
 adjusting existing practices to comply with requirements;
 searching data sources;
 completing and reviewing the response; and
 transmitting or disclosing information.
Agencies must provide information to OMB on the parties affected, the annual reporting burden, the
annualized cost of responding to the information collection, and whether the request significantly
impacts a substantial number of small entities. An agency may not conduct or sponsor, and a person
is not required to respond to, an information collection unless it displays a currently valid OMB
control number.
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OMB has previously approved the information collection requirements contained in the existing
pipeline safety regulations under the provisions of the Paperwork Reduction Act.
The IFR modifies the information collection requirements for operators of natural gas storage
facilities. PHMSA estimated changes in reporting and recordkeeping burden in Section 5.1.4 and is
submitting a revised Information Collection Request (ICR) to OMB for approval.
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Regulatory Impact Analysis: Underground Natural Gas Storage 9. References
9 References
American Gas Association (AGA). 2014. Survey of Underground Storage of Natural Gas in the
United States and Canada: 2013/2014.
American Gas Association (AGA). 2015. Natural Gas Utility Rate Structure: The Customer Charge
Component – 2015 Update. EA 2015-03. May 28, 2015.
American Petroleum Institute (API). 201a. API Recommended Practice 1170: Design and Operation
of Solution-mined Salt Caverns Used for Natural Gas Storage. First Edition, July 2015.
American Petroleum Institute (API). 201b. API Recommended Practice 1171: Functional Integrity of
Natural Gas Storage in Depleted Hydrocarbon Reservoirs and Aquifer Reservoirs. First
Edition, September 2015.
Bardwell, S.K. and C. Horswell. 2004. Valve Failure Sends Flames into Sky at Moss Bluff Storage
Facility. Houston Chronicle. August 20.
British Geological Survey. 2008. An appraisal of underground gas storage technologies and
incidents, for the development of risk assessment methodology. Research Report RR605.
Bureau of Labor Statistics (BLS). (2016). “May 2015 National Industry-Specific Occupational
Employment and Wage Estimates: NAICS 211100.” Available at
http://www.bls.gov/oes/current/naics4_211100.htm#11-0000; Accessed November 29, 2016.
California Air Resources Board (CARB). 2016a. Determination of Total Methane Emissions from
the Aliso Canyon Natural Gas Leak Incident. October 21, 2016.Available at
https://www.arb.ca.gov/research/aliso_canyon/aliso_canyon_methane_emissions-
arb_final.pdf.
California Air Resources Board (CARB). 2016b. Aliso Canyon Methane Leak Climate Impacts
Mitigation Program. March 31, 2016.
California Department of Conservation. 2016a. Oil, Gas and Geothermal Idle Well Program. Web
page. Available at http://www.conservation.ca.gov/dog/idle_well
California Department of Conservation. 2016b. State Announces Comprehensive Natural Gas
Storage and Inspection Mandates. Press Release. NR#2016-3. February 5, 2016. Available at
http://www.conservation.ca.gov/index/Documents/2016-0 Emergency regulations for natural
gas storage wells go into effect.pdf
County of Los Angeles Public Health. Aliso Canyon Gas Leak Public Health Assessment:
Environmental Conditions and Health Concerns in Proximity to Aliso Canyon Following
Permanent Closure of Well SS-25. May 13, 2016.
Energy Information Administration (EIA). 2015. The Basics of Underground Natural Gas Storage.
November 16, 2015. Available at http://www.eia.gov/naturalgas/storage/basics/ (Accessed
May 18, 2016)
Energy Information Administration (EIA). 2016a. U.S. Underground Natural Gas Storage – All
Operators, Released April 29, 2016. Available at
http://www.eia.gov/dnav/ng/ng_stor_sum_dcu_nus_a.htm.
9-1

<<<PAGE 59>>>

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(Summary), Released April 29, 2016. Available at
http://www.eia.gov/dnav/ng/ng_stor_cap_a_epg0_sac_mmcf_a.htm.
Energy Information Administration (EIA). 2016c. Number of Natural Gas Residential Consumers,
Released April 29, 2016. Available at
http://www.eia.gov/dnav/ng/ng_cons_num_a_epg0_vn3_count_a.htm.
Energy Information Administration (EIA). 2016d. U.S. Natural Gas Consumption by End Use,
Released April 29, 2016. Available at
http://www.eia.gov/dnav/ng/ng_cons_sum_dcu_nus_a.htm.
Energy Information Administration (EIA). 2016e. Natural Gas Annual Respondent Query System
(EIA-191 Data through 2015), Release Date March 2016. Available at
http://www.eia.gov/cfapps/ngqs/ngqs.cfm?f_report=RP7
Energy Information Administration (EIA). 2016f. Trends in U.S. Oil and Natural Gas Upstream
Costs. March 2016. Available at
https://www.eia.gov/analysis/studies/drilling/pdf/upstream.pdf.
Federal Energy Regulatory Commission (FERC). 2016. Jurisdictional Storage Fields in the United
States. Available at https://www.ferc.gov/industries/gas/indus-act/storage/sortable.xlsx;
accessed March 28, 2016.
Honeoye Storage Corporation. 2015. Honeoye Storage Corporation 2015 Newsletter. Available at
http://www.honeoyestoragecorp.com/newsletter.htm; Accessed June 3, 2016
Hopper, J.M. 2004. Gas Storage and Single-point Failure. Natural Gas.
Interagency Working Group on the Social Cost of Greenhouse Gases (IWGSCGG). 2016. Addendum
to Technical Support Document on Social Cost of Carbon for Regulatory Impact Analysis
under Executive Order 12866: Application of the Methodology to Estimate the Social Cost of
Methane and the Cost of Nitrous Oxide. August 2016. Available at
https://www.whitehouse.gov/sites/default/files/omb/inforeg/august_2016_sc_ch4_sc_n2o_ad
dendum_final_8_26_16.pdf
Intergovernmental Panel on Climate Change (IPCC). 2013 Climate Change 2013: The Physical
Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the
Intergovernmental Panel on Climate Change. [Stocker, T.F., D. Qin, G.-K., Plattner, M.
Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)].
Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA,
1535 pp.
Interagency Task Force on Natural Gas Storage Safety. 2016. Ensuring Safe and Reliable
Underground Natural Gas Storage. October 2016. Available at
http://energy.gov/sites/prod/files/2016/10/f33/Ensuring Safe and Reliable Underground
Natural Gas Storage – Final Report.pdf; Accessed November 23, 2016.
Interstate Natural Gas Association of America (INGAA). 2016. Response to PHMSA Questions.
Personal Communication from Terry D. Boss (INGAA) to John Gale (PHMSA). May 9,
2016.
9-2

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Joint Institute for Strategic Energy Analysis (JISEA). 2015. Estimating U.S. Methane Emissions
from the Natural Gas Supply Chain: Approaches, Uncertainties, Current Estimates, and
Future Studies. Technical Report NREL/TP-6A50-62820. August 2015
Joyce S. and J. Wirfs-Brock. The Rising Cost of Cleaning up After Oil and Gas. Inside Energy.
October 1, 2015. Available at http://insideenergy.org/2015/10/01/the-rising-cost-of-cleaning-
up-after-oil-and-gas/
Kansas Geological Survey. 2004. Natural Gas Explosions in Hutchison, Kansas: Geologic Factors.
August 20, 2004. Available at
http://www.kgs.ku.edu/Hydro/Hutch/GSA_Watney_updated082004.pdf
OGJ. 2004. Second Moss Bluff Explosion Accesses 6 BCF of Gas in Cavern, Feeds Larger Fire.
August 20, 2004.
Pacific Gas and Electric Company (PG&E). 2016. PG&E Safely Operates its Natural Gas Storage
Facilities. Currents. February 5, 2016. Available at
http://www.pgecurrents.com/2016/02/05/pge-safely-operates-its-natural-gas-storage-
facilities/. Accessed May 15, 2016.
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Assessment. Notice of Proposed Rulemaking - Pipeline Safety: Safety of Gas Transmission
and Gathering Pipelines. March 2016
Pipeline and Hazardous Safety Administration (PHMSA). 2016b. Unit Component Gas Storage
Fields Report. Data as of April 5, 2016.
Puget Sound Energy. 2016. Jackson Prairie Gas Storage. Presentation to Washington State Utilities
& Transportation Commission Citizens Committee on Pipeline Safety. March 22, 2016.
Available at
http://www.utc.wa.gov/publicSafety/Documents/PSE%20Presentation%20on%20Jackson%2
0Prairie%20Operation.pdf. Accessed June 10, 2016.
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at https://www.census.gov/econ/isp/sampler.php?naicscode=486&naicslevel=3#. Accessed
June 1, 2016.
U.S. Environmental Protection Agency (U.S. EPA). 2008. Methane to Markets: Reducing Methane
Emissions from Underground Natural Gas Storage Operations. Gazprom – EPA Technical
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Sinks: 1990-2012. EPA 430-R-14-003. Washington, D.C.
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Proposed Emission Standards for New and Modified Sources in the Oil and Natural Gas
Sector. EPA-452/R-15-002, August 2015.
9-3

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1990-2014.
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Emissions of CH4, N2O, and Indirect Greenhouse Gases from Stationary Combustion.
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November 23, 2016.
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at https://www.whitehouse.gov/sites/default/files/omb/assets/regulatory_matters_pdf/a-4.pdf
U.S. Office of Management and Budget (OMB). Not dated. Regulatory Impact Analysis: A Primer.
Available at https://www.whitehouse.gov/sites/default/files/omb/inforeg/regpol/circular-a-
4_regulatory-impact-analysis-a-primer.pdf
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7E59-423E-955D-D21499D8AB52/Q3-16_Presentation.pdf; Accessed November 23, 2016
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North American Industry Classification System Codes. Effective February 26, 2016.
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the Public Utilities Commission of the State of California. November 2014.
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inactive-well-requirements/cost-calculation/
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Locker on Behalf of Public Service Company of Coloraro. March 3, 2015.
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Allen L. Robinson. 2015. Methane Emissions from the Natural Gas Transmission and
Storage System in the United States. Environ. Sci. Technol. 2015, 49, 9374−9383.
9-4

<<<PAGE 62>>>

Regulatory Impact Analysis: Underground Natural Gas Storage Appendix A. Summary of API RPs
Appendix A – Summary of API Recommended Practices
The tables below summarize the scope of API RP 1170 and API RP 1171 and provide examples of
measures and associated operator actions. Note that this is a condensed summary of the RP and the
reader should refer to the respective documents for details on the measures.
1
Exhibit A-1: Summary of RP 1170 Measures with Associated Operator Actions.
Title: Design and Operation of Solution-mined Salt Caverns Used for Natural Gas Storage
Scope overview: This recommended practice (RP) provides the functional recommendations for salt cavern facilities
used for natural gas storage service and covers facility geomechanical assessments, cavern well design and drilling,
solution mining techniques and operations, including monitoring and maintenance practices. This RP includes the
cavern well system (wellhead, wellbore, and cavern) from the emergency shutdown (ESD) valve down to the cavern
and facilities having significant impact to safety and integrity of the cavern system.
RP Section Scope or Facility Components Selected Measures and Operator Actions
5. Geological and
Geomechanical
Evaluation
 Site selection criteria
 Geologic site characterization
 Geomechanical site
characterization
 Assessment of cavern stability
and geomechanical performance
 Select and assess the site to ensure that the
salt deposit is suitable for cavern development.
RP describes steps in the assessment process
and tests that should be done to verify site
suitability.
6. Well Design  Hole section design
 Casing design (conductor casing,
surface casing, intermediate
casing, production casing)
 Wellhead design
 Design the storage well system to ensure
confinement of the stored gas to the cavern
system. The RP describes design
considerations and the design, operational, and
maintenance procedures that should be
included to ensure integrity
7. Drilling  Rig and equipment
 BOP system
 Drilling guidelines
 Logging
 Cementing
 Completion
 Select drilling equipment and logging
procedures to achieve the desired well design
and ensure safety. The RP describes the type of
equipment needed and selection considerations
8. Cavern Solution
Mining
 Cavern solution mining design
 Cavern development phases
 Equipment
 Instrumentation, control, and shut
down
 Workover during solution mining
 Workover to configure for gas
storage service
 Debrining the cavern
 Existing cavern conversions
 Cavern rewatering
 Cavern enlargement
 Design and develop the cavern to store gas.
The RP discusses the design considerations,
equipment and instrumentations needed,
monitoring during development phase, and
workover procedures.
A-1

<<<PAGE 63>>>

Regulatory Impact Analysis: Underground Natural Gas Storage Appendix A. Summary of API RPs
1
Exhibit A-1: Summary of RP 1170 Measures with Associated Operator Actions.
Title: Design and Operation of Solution-mined Salt Caverns Used for Natural Gas Storage
Scope overview: This recommended practice (RP) provides the functional recommendations for salt cavern facilities
used for natural gas storage service and covers facility geomechanical assessments, cavern well design and drilling,
solution mining techniques and operations, including monitoring and maintenance practices. This RP includes the
cavern well system (wellhead, wellbore, and cavern) from the emergency shutdown (ESD) valve down to the cavern
and facilities having significant impact to safety and integrity of the cavern system.
RP Section Scope or Facility Components Selected Measures and Operator Actions
9. Gas Storage
Operations
 Minimum and maximum
operating limits
 Equipment
 Instrumentation, control, and shut
down
 Inspection and testing
 Workovers
 Site security and safety
 Operating administration
 Equip and monitor the cavern to ensure safe
operation and detect upset conditions, including
by installing SCADA systems, alarms, ESD
system, overpressure protection system, and
fire and gas detection.
 Test and calibrate equipment and safety devices
at least annually.
 Have O&M procedures to allow the safe
operation and necessary maintenance of the
wellhead and cavern to ensure integrity. The RP
lists some of the procedures that should be in
place.
 Maintain records of system development and
O&M at least until the facility is
decommissioned.
10. Cavern Integrity
Monitoring
 Integrity monitoring program  Monitor the cavern to ensure functional integrity.
The RP describes various integrity monitoring
methods applicable to the cavern system,
wellbore, cavern, and wellhead
11. Cavern
Abandonment
 Abandonment design
 Removal of stored gas
 Wellbore integrity test
 Removal of downhole equipment
 Production casing inspection
 Sonar survey
 Long-term monitoring

 Stabilize the cavern and maintain hydraulic
integrity
1 This table provides only a summary of selected measures. Refer to the full text of the API RP for details on the
measures.
1
Exhibit A-2: Summary of RP 1171 Measures with Associated Operator Actions.
Title: Functional Integrity of Natural Gas Storage in Depleted Hydrocarbon Reservoirs and Aquifer Reservoirs
Scope Overview: This recommended practice (RP) applies to natural gas storage in depleted oil and gas reservoirs
and aquifer reservoirs, and focuses on storage well, reservoir, and fluid management for functional integrity in design,
construction, operation, monitoring, maintenance, and documentation practices. This RP applies to both existing and
newly constructed facilities. However, Sections 5 and 7 apply exclusively to new facilities and facilities undergoing
expansion, and Section 6 applies to new well construction and remediation of a new or existing well.
RP Section Scope or Facility Components Selected Measures and Operator Actions
5. Functional Integrity
in Design of Reservoir
 Geological reservoir
characterization
 Engineering reservoir
characterization
 Containment assurance of
reservoir design
 Environmental, safety, and health
considerations in design
 Assess and design new natural gas storage
capacity development in hydrocarbon
production reservoirs and aquifer reservoirs,
and increased maximum pressure and/or total
capacity in existing natural gas storage
reservoirs. RP provides guidance on
considerations and steps.
 Maintain accurate and comprehensive records
of natural gas storage design activities for the
life of the facility. RP lists records needing to be
maintained as applicable and available.
A-2

<<<PAGE 64>>>

Regulatory Impact Analysis: Underground Natural Gas Storage Appendix A. Summary of API RPs
1
Exhibit A-2: Summary of RP 1171 Measures with Associated Operator Actions.
Title: Functional Integrity of Natural Gas Storage in Depleted Hydrocarbon Reservoirs and Aquifer Reservoirs
Scope Overview: This recommended practice (RP) applies to natural gas storage in depleted oil and gas reservoirs
and aquifer reservoirs, and focuses on storage well, reservoir, and fluid management for functional integrity in design,
construction, operation, monitoring, maintenance, and documentation practices. This RP applies to both existing and
newly constructed facilities. However, Sections 5 and 7 apply exclusively to new facilities and facilities undergoing
expansion, and Section 6 applies to new well construction and remediation of a new or existing well.
RP Section Scope or Facility Components Selected Measures and Operator Actions
6. Functional Integrity
in Design of Storage
Wells
 Wellhead equipment and valves
 Well casing
 Casing cementing practices
 Completion and stimulation
 Well remediation
 Well closure (plugging and
Abandonment)
 Environmental, safety and health
 Testing and commissioning
 Monitoring of construction
activities
 Ensure functional integrity in the design,
construction, and completion of new natural gas
storage wells, the remediation and
reconditioning of existing wells, and
abandonment of wells within a natural gas
storage facility. RP provides consideration and
measures to provide this assurance
7. Functional Integrity
of the Natural Gas
Storage Reservoir and
Wells Established and
Demonstrated
Through Initial
Attainment of
Maximum Reservoir
Pressure and Total
Inventory
 Testing and commissioning
 Reservoir integrity monitoring
 Mechanical integrity monitoring
 Verify functional integrity of the natural gas
storage reservoir and wells during reservoir
development and during commissioning until
reaching the designed maximum reservoir
pressure and/or total capacity.
 Establish and document baseline conditions.
 Monitor material balance behavior of the storage
reservoir. RP provides monitoring and analysis
methods such as reservoir pressure monitoring,
use of observation wells, gas identification logs.
 Monitor wells and related facilities. RP describes
measures for wellheads, well safety systems,
piping, and site locations, wellhead injection
pressure and flow rate, observation well
pressures and fluid levels, and well annulus
pressures or vents.
 Maintain records of natural gas storage testing
and monitoring activities conducted during
commissioning for the life of the facility. RP lists
records needing to be maintained as applicable
and available.
8. Risk management
for gas storage
operations
 Risk management
 Data collection and integration
 Threat and hazard identification
and analysis
 Risk assessment
 Preventative and mitigative
measures
 Periodic review and assessment
 Develop, implement, and document a program
to manage risk. Measures include: data
collection, identification of potential threats and
hazards to the storage operation, risk analysis
including estimation of the likelihood of
occurrence of events related to each threat, the
likelihood of occurrence and potential severity of
the consequences of such events, and the
preventive, mitigative, and monitoring processes
to reduce the likelihood of occurrence and/or the
likelihood and severity of consequences, and a
periodic review and reassessment of the
processes.
A-3

<<<PAGE 65>>>

Regulatory Impact Analysis: Underground Natural Gas Storage Appendix A. Summary of API RPs
1
Exhibit A-2: Summary of RP 1171 Measures with Associated Operator Actions.
Title: Functional Integrity of Natural Gas Storage in Depleted Hydrocarbon Reservoirs and Aquifer Reservoirs
Scope Overview: This recommended practice (RP) applies to natural gas storage in depleted oil and gas reservoirs
and aquifer reservoirs, and focuses on storage well, reservoir, and fluid management for functional integrity in design,
construction, operation, monitoring, maintenance, and documentation practices. This RP applies to both existing and
newly constructed facilities. However, Sections 5 and 7 apply exclusively to new facilities and facilities undergoing
expansion, and Section 6 applies to new well construction and remediation of a new or existing well.
RP Section Scope or Facility Components Selected Measures and Operator Actions
9. Integrity
Demonstration,
Verification, and
Monitoring Practices
 Well integrity identification and
analysis
 Risk assessment
 Preventative and mitigative
measures
 Periodic review and assessment
 Evaluate the mechanical integrity of each active
well that penetrates the storage reservoir and
buffer zone or areas influenced by storage
operations.
 RP discusses measures including review of
design, completion, and well work records,
wellhead and downhole inspection, well
pressure monitoring and testing, and gas
sampling.
 Monitor well integrity. RP provides expected
frequencies for some inspections and tests.
 Document inspections, tests and patrols and
maintain records for the life of the facility.
10. Site Security and
Safety, Site
Inspections, and
Emergency
Preparedness and
Response
 Site security and safety
 Ingress and egress
 Signage
 Site inspections
 Emergency
preparedness/emergency
response
 Assess and monitor site security and
emergency preparedness
 Develop and implement an emergency
preparedness/response plan and provide
training to applicable staff. RP lists element of
the Plan and training scope and activities.
 Have in place a blowout contingency plan
11. Procedures and
Training
 Procedures  Develop, implement, and maintain programs,
plans, and procedures for O&M, emergency
plans, well work, other well entry and well
operation, interaction with control room, integrity
and risk management, safety and environmental
programs, public awareness and damage
prevention, management of change, and
training.
1 This table provides only a summary of selected measures. Refer to the full text of the API RP for details on the
measures.
A-4

<<<PAGE 66>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
Appendix B. Operator-level Costs
Appendix B - Operator-level Costs
Exhibit B-1: Estimated Mechanical Integrity Testing Costs per Operator under Partial Compliance
Baseline Scenario
Operator Name
Number Number
of
Number Total Costs
Annualized
Total
Fields
of Wells'
of Wells
Tested
(Thousand,
2015$3
Costs (7%;
2015$/Year)3,4
Thousand
AMEREN ILLINOIS
14
12
409
$0
$0
ANR PIPELINE COMPANY
932
$0
$0
ARCADIA GAS STORAGE LLC
1
6
6
$88
ARLINGTON GAS STORAGE COMPANY LLC
3
23
23
ATMOS ENERGY CORPORATION
12
154
$0
$0
ATMOS PIPELINE TEXAS
5
56
$O
$0
BAY GAS STORAGE COMPANY LTD
$0
BEAR CREEK STORAGE COMPANY
$0
$0
$0
BLUE LAKE STORAGE COMPANY
14
$0
$O
BLUEWATER GAS STORAGE LLC
$O
$0
BOARDWALK LOUISIANA MIDSTREAM LLC
$O
$O
BOBCAT GAS STORAGE
$0
BRIDGELINE HOLDINGS LP
$380
CADEVILLE GAS STORAGE
CALEDONIA ENERGY PARTNERS LLC
$1,900
$0
$
CENTANA INTERSTATE PIPELINE LLC
$760
$1
101
CENTERPOINT ENERGY
33
,534
$8
6
CENTRAL NEW YORK OIL AND GAS COMPANY
33
$75
CENTRAL VALLEY GAS STORAGE LLC
1
CENTURY ALUMINUM SEBREE
CHEROKEE WELLS LLC
37
CHEVRON KEYSTONE GAS STORAGE, LLC
5
CHEVRON PHILLIPS CHEMICAL CO LP
1
CITIZENS ENERGY GROUP
2
CITY OF ELIZABETHTOWN NATURAL GAS
$0
93
$0
CLEAR CREEK STORAGE COMPANY LLC
$O
COLORADO INTERSTATE GAS COMPANY
COLUMBIA GAS OF PA INC
COLUMBIA GAS TRANSMISSION LLC
32
3,362
$0
$0
CONSUMERS ENERGY COMPANY
14
981
COOK INLET NATURAL GAS STORAGE
35
35
CRANBERRY PIPELINE CORPORATION
DELTA NATURAL GAS COMPANY INC
1
4
11
$0
DOMINION EAST OHIO
780
DOMINION TRANSMISSION INC
15
1431
DOW PL CO
1
EAST CHEYENNE GAS STORAGE LLC
1
$0
EATON RAPIDS GAS STORAGE SYSTEM
14
$0
EGYPTIAN GAS STORAGE CORPORATION
EL PASO NATURAL GAS COMPANY
20
ENABLE GAS TRANSMISSION LLC
71
B-1

<<<PAGE 67>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
Appendix B. Operator-level Costs
Exhibit B-1: Estimated Mechanical Integrity Testing Costs per Operator under Partial Compliance
Baseline Scenario
Operator Name
Number Number
of
Number Total Costs
Annualized
Total
Fields
of Wells'
of Wells
Tested
(Thousand,
2015$)
Costs (7%;
2015$/Year 3,4
Thousand
ENABLE MIDSTREAM PARTNERSENOGEX
2
$0
$0
ENABLE MISSISSIPPI RIVER TRANSM CORP
3
91
$0
$0
ENERGY TRANSFER FUEL LP
2
29
$0
$0
ENLINK MIDSTREAM SERVICES LLC
1
$0
$0
ENSTOR GRAMA RIDGE STORAGE TRANSP
1
5
5
$1,650
ENSTOR KATY STORAGE TRANSPLP
1
12
$0
$0
ENTERPRISE TEXAS PIPELINE
1
$0
$0
EQUITRANS L P
17
351
$0
$0
FORT CONCHO GAS STORAGE INC
$0
$0
FREEBIRD GAS STORAGE LLC
FREEPORT LNG DEVELOPMENT LP
GILL RANCH STORAGE LLC
19
$0
GOLDEN TRIANGLE STORAGE INC
GULF SOUTH PIPELINE
2
2
90
90
HAMPSHIRE GAS CO
2
17
17
HARDY STORAGE COMPANY LLC
24
$0
HILCORP ALASKA LLC
130
130
HILL LAKE GAS STORAGE LLC
HONEYE STORAGE CORPORATION
11
38
HOUSTON PIPE LINE COMPANY
46
INDIANA GAS COMPANY DBA VECTREN
156
ON OOOO
JEFFERSON ISLAND STORAGE AND HUB LLC
2
KINDER MORGAN INTERSTATE GAS TRNAMIS
51
$0
KINDERMORGAN TEXAS PIPELINE LP
29
$0
$0
LACLEDE GAS COMPANY
81
81
Leaf River Energy Center
4
$0
$0
LEE 8 STORAGE PARTNERSHIP
LODI GAS STORAGE LLC
∞ O
LOUISVILLE GAS AND ELECTRIC COMPANY
296
MICHIGAN CONSOLIDATED GAS COMPANY
LOWER COLORADO RIVER AUTHORITY
102
$0
$0
MICHIGAN GAS UTILITIES CORPORATION
1
12
MID CONTINENT CENTER
2
20
$0
$0
MISSISSIPPI HUB LLC
1
0
$0
$0
MONROE GAS STORAGE COMPANY LLC
1
1,212
23
23
NATIONAL FUEL GAS SUPPLY CORP
30
$0
$0
NATURAL GAS PIPELINE CO OF AMERICA
691
• °
$0
$0
NGO DEVELOPMENT CORPORATION
0
$0
$0
NGO TRANSMISSION INC
516
49
49
$917
NORTHERN ILLINOIS GAS COMPANY
0 0
$0
$0
NORTHERN INDIANA PUBLIC SVC C
84
$0
$0
NORTHERN NATURAL GAS COMPANY
338
338
$5,775
NORTHWESTERN CORP DBA NW ENERGY
72
72
$1,083
NW NATURAL
43
43
$593
B-2

<<<PAGE 68>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
Appendix B. Operator-level Costs
Exhibit B-1: Estimated Mechanical Integrity Testing Costs per Operator under Partial Compliance
Baseline Scenario
Operator Name
Number Number
of
Number Total Costs
Annualized
Total
Fields
of Wells'
of Wells
Tested
(Thousand,
2015$3
Costs (7%;
2015$/Year) 3,4
Thousand
ONEOK GAS STORAGE LLC
4
77
$0
$0
ONEOK TEXAS GAS STORAGE LP
2
8
$0
$0
PACIFIC GAS AND ELECTRIC COMPANY
116
$0
$0
PB ENERGY STORAGE SERVICES INC
1
2
2
$380
$51
PEOPLES GAS LIGHT AND COKE COMPANY
1
202
$0
$0
PEOPLES NATURAL GAS COMPANY
1
9
$0
$0
PEOPLES TWP LLC
4
19
$0
$0
PERRYVILLE GAS STORAGE LLO
1
1
PETAL GAS STORAGE LLC
1
$110
$15
$0
PINE PRAIRIE ENERGY CENTER LLC
PONTCHARTRAIN NATURAL GAS SYSTEM
PUBLIC SERVICE COMPANY OF COLORADO
4
PUGET SOUND ENERGY
103
QUESTAR PIPELINE COMPANY
78
ROCKY MOUNTAIN NATURAL GAS
10
$1,900
$2
RYCKMAN CREEK RESOURCES LLC
$0
$O
SALT PLAINS STORAGE LLC
30
$5,130
$683
SEMCO ENERGY GAS COMPANY
SG RESOURCES MISSISSIPPI LLC
$2,090
$950
SOURCEGAS DISTRIBUTION LLC
$2,
,530
$337
SOUTHERN CALIFORNIA GAS COMPANY
196
$0
SOUTHERN INDIANA GAS ELECTRIC
132
SOUTHERN NATURAL GAS COMPANY
73
SOUTHERN STAR CENTRAL GAS PIPELINE
599
$O
SOUTHWEST GAS STORAGE COMPANY
STECKMAN RIDGE LP
227
13
$0
TENNESSEE GAS PIPELINE COMPANY
52
$0
TEXAS EASTERN TRANSMISSION LP
138
$0
TRANSCONTINENTAL GAS PIPELINE
TEXAS GAS TRANSMISSION CORPORATION
497
$0
$0
COMPANY
51
$0
$0
TRES PALACIOS GAS STORAGE LLC
1
3
3
$330
$44
TRUNKLINE GAS COMPANY
1
62
62
$6,138
$817
UGI STORAGE COMPANY
1
3
3
$570
$76
UNDERGROUND SERVICES MARKHAM LP
1
5
5
$950
$126
UNDERGROUND STORAGE LLC
1
1
$0
$0
WILD GOOSE STORAGE INC
1
21
$0
$0
WILLISTON BASIN INTERSTATE PIPELINE
2
203
203
$20,097
$2,674
WORSHAM STEED GAS STORAGE LLC
1
57
$0
$0
WYCKOFF GAS STORAGE
1
$0
$0
Operators for which the number of wells is equal to 0 indicate fields identified in EIA (2016e) but not included in the
TOTAL
16,991
2,408
$271,535
$36,131
AGA (2014) inventory.
2 Number of wells tested is less than the total number of wells presented in the column to the left in cases where
wells are already covered under an existing operator commitment or regulated by the state where the facility is
B-3

<<<PAGE 69>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
Appendix B. Operator-level Costs
Exhibit B-1: Estimated Mechanical Integrity Testing Costs per Operator under Partial Compliance
Baseline Scenario
Total
Operator Name
Number Number
of
Number Total Costs
Fields
of Wells'
of Wells
Tested
(Thousand,
Annualized
2015$)
Costs (7%;
2015$/Year)3,
Thousand
located.
member, has an existing integrity testing program, and/or operates only intrastate fields in states with existing
" Costs may be $0 for certain operators with greater than O number of wells in cases where the operator is an INGAA
* Costs annualized using a 7 percent discount rate over 10 years (assuming tests conducted every 10 years).
Exhibit B-2: Estimated Mechanical Integrity Testing Costs per Operator under Regulatory
Compliance Only Baseline Scenario
Operator Name
Number Number
of
Number Total Costs
Annualized
Total
Fields
of Wells' of Wells
Tested
(Thousand,
2015$3
Costs (7%;
2015$/Year 3,4
Thousand
AMEREN ILLINOIS
12
409
14
932
932
$112,078
$0
$0
ANR PIPELINE COMPANY
$14,913
ARCADIA GAS STORAGE LLC
1
6
6
$660
$88
ARLINGTON GAS STORAGE COMPANY LLC
12
3
23
23
$3,982
$530
ATMOS ENERGY CORPORATION
154
$0
$0
ATMOS PIPELINE TEXAS
5
1
56
$0
$0
BAY GAS STORAGE COMPANY LTD
2
$0
$0
BEAR CREEK STORAGE COMPANY
74
74
$21,978
$2,924
BLUE LAKE STORAGE COMPANY
14
14
$2,394
$319
BLUEWATER GAS STORAGE LLC
$0
$0
BOARDWALK LOUISIANA MIDSTREAM LLC
NO
2
$380
$51
BOBCAT GAS STORAGE
$0
$0
BRIDGELINE HOLDINGS LP
10
2
2
$380
$51
CADEVILLE GAS STORAGE
10
$1,900
$253
CALEDONIA ENERGY PARTNERS LLC
1
$0
$0
CENTANA INTERSTATE PIPELINE LLC
1
4
4
$760
$101
CENTERPOINT ENERGY
1
66
66
$6,534
$869
CENTRAL NEW YORK OIL AND GAS COMPANY
1
1
33
33
$5,643
$751
CENTRAL VALLEY GAS STORAGE LLC
12
$0
$0
CENTURY ALUMINUM SEBREE
1
4
$0
$0
CHEROKEE WELLS LLC
2
37
$0
$0
CHEVRON KEYSTONE GAS STORAGE, LLC
1
5
$0
$0
CHEVRON PHILLIPS CHEMICAL CO LP
1
$0
$0
CITIZENS ENERGY GROUP
224
$0
$0
CITY OF ELIZABETHTOWN NATURAL GAS
193
$0
$0
CLEAR CREEK STORAGE COMPANY LLC
1
$0
$0
COLORADO INTERSTATE GAS COMPANY
233
233
$42,867
COLUMBIA GAS OF PA INC
1
8
$0
$5,704
$0
COLUMBIA GAS TRANSMISSION LLC
32
3,362
3,362
$382,621
$50,913
CONSUMERS ENERGY COMPANY
14
981
981
$97,262
$12,942
COOK INLET NATURAL GAS STORAGE
1
35
35
$3,503
$466
B-4

<<<PAGE 70>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
Appendix B. Operator-level Costs
Exhibit B-2: Estimated Mechanical Integrity Testing Costs per Operator under Regulatory
Compliance Only Baseline Scenario
Operator Name
Number Number
of
Number Total Costs
Annualized
Total
Fields
of Wells'
of Wells
Tested
(Thousand,
2015$3
Costs (7%;
20158/Year) 3,4
Thousand
CRANBERRY PIPELINE CORPORATION
1
4
4
$440
$59
DELTA NATURAL GAS COMPANY INC
1
11
0
$0
$0
DOMINION EAST OHIO
15
3
780
780
$133,380
$17,748
DOMINION TRANSMISSION INC
1,431
1,431
$180,608
$24,032
DOW PL CO
1
1
$0
$0
EAST CHEYENNE GAS STORAGE LLC
1
$0
$0
EATON RAPIDS GAS STORAGE SYSTEM
1
14
14
$2,394
$319
EGYPTIAN GAS STORAGE CORPORATION
1
$0
$0
EL PASO NATURAL GAS COMPANY
20
20
$3,420
$455
ENABLE GAS TRANSMISSION LLC
71
71
$9,648
$1,284
ENABLE MIDSTREAM PARTNERSENOGEX
$0
$0
ENABLE MISSISSIPPI RIVER TRANSM CORP
91
91
$24,651
$3,280
ENERGY TRANSFER FUEL LP
29
$0
$0
ENLINK MIDSTREAM SERVICES LLC
11
$0
ENSTOR GRAMA RIDGE STORAGE TRANSP
12
5
5
$1,650
$220
ENSTOR KATY STORAGE TRANSPLP
1
$0
$0
ENTERPRISE TEXAS PIPELINE
$0
$0
EQUITRANS L P
FORT CONCHO GAS STORAGE INC
17
351
329
$33,011
$4,393
1
16
$0
$0
FREEBIRD GAS STORAGE LLC
$0
$0
FREEPORT LNG DEVELOPMENT LP
$0
$0
GILL RANCH STORAGE LLC
1
19
0
$0
$0
GOLDEN TRIANGLE STORAGE INC
1
2
2
$380
$51
GULF SOUTH PIPELINE
2
90
90
$14,238
$1,895
HAMPSHIRE GAS CO
2
17
17
$3,230
$430
HARDY STORAGE COMPANY LLC
1
24
24
$7,128
$948
HILCORP ALASKA LLC
130
130
$13,027
$1,733
HILL LAKE GAS STORAGE LLC
11
$0
$0
HONEYE STORAGE CORPORATION
38
38
$3,762
$501
HOUSTON PIPE LINE COMPANY
46
$0
INDIANA GAS COMPANY DBA VECTREN
4
156
° ON
$0
$0
$0
JEFFERSON ISLAND STORAGE AND HUB LLC
2
$380
$51
KINDER MORGAN INTERSTATE GAS TRNAMIS
51
51
$8,721
KINDERMORGAN TEXAS PIPELINE LP
3
29
$1,160
$0
$0
LACLEDE GAS COMPANY
81
81
$8,019
$1,067
Leaf River Energy Center
4
$0
$0
LEE 8 STORAGE PARTNERSHIP
LODI GAS STORAGE LLC
8
$880
$117
• 0 ∞
$0
$0
LOUISVILLE GAS AND ELECTRIC COMPANY
LOWER COLORADO RIVER AUTHORITY
1O r
296
$0
$0
$0
$0
MICHIGAN CONSOLIDATED GAS COMPANY
5
102
102
$10,197
$1,357
MICHIGAN GAS UTILITIES CORPORATION
12
12
$1,188
$158
MID CONTINENT CENTER
20
$0
$0
MISSISSIPPI HUB LLC
1
$0
$0
B-5

<<<PAGE 71>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
Appendix B. Operator-level Costs
Exhibit B-2: Estimated Mechanical Integrity Testing Costs per Operator under Regulatory
Compliance Only Baseline Scenario
Operator Name
Number Number
of
Number Total Costs
Annualized
Total
Fields
of Wells'
of Wells
Tested
(Thousand,
2015$)
Costs (7%;
20158/Year) 3,4
Thousand
MONROE GAS STORAGE COMPANY LLC
1
23
23
$2,277
$303
NATIONAL FUEL GAS SUPPLY CORP
30
1,212
1,212
$136,300
$18,136
NATURAL GAS PIPELINE CO OF AMERICA
8
691
535
$60,093
$7,996
NGO DEVELOPMENT CORPORATION
2
$0
$0
NGO TRANSMISSION INC
3
49
$6,894
$917
NORTHERN ILLINOIS GAS COMPANY
8
516
$0
$0
NORTHERN INDIANA PUBLIC SVC C
2
84
$0
$0
NORTHERN NATURAL GAS COMPANY
3
338
00
$43,398
$5,775
NORTHWESTERN CORP DBA NW ENERGY
3
72
$8,141
$1,083
NW NATURAL
^ +
43
$4,455
$593
ONEOK GAS STORAGE LLC
77
$9,533
$1,268
ONEOK TEXAS GAS STORAGE LP
8
$0
$0
PACIFIC GAS AND ELECTRIC COMPANY
116
$0
PB ENERGY STORAGE SERVICES INC
2
•ON OO
$380
$51
PEOPLES GAS LIGHT AND COKE COMPANY
202
$0
$0
PEOPLES NATURAL GAS COMPANY
9
$0
$0
PEOPLES TWP LLC
19
$0
PERRYVILLE GAS STORAGE LLC
$110
$15
PETAL GAS STORAGE LLC
$1,470
$196
PINE PRAIRIE ENERGY CENTER LLC
1
5
5
$950
$126
PONTCHARTRAIN NATURAL GAS SYSTEM
1
$190
$25
PUBLIC SERVICE COMPANY OF COLORADO
3
46
46
$6,952
$925
PUGET SOUND ENERGY
103
103
$10,197
$1,357
QUESTAR PIPELINE COMPANY
78
78
$10,978
$1,461
ROCKY MOUNTAIN NATURAL GAS
10
10
$1,900
$253
RYCKMAN CREEK RESOURCES LLC
0
$0
$0
SALT PLAINS STORAGE LLC
30
30
$5,130
$683
SEMCO ENERGY GAS COMPANY
19
19
$2,090
$278
SG RESOURCES MISSISSIPPI LLC
23
5
5
$950
$126
SOURCEGAS DISTRIBUTION LLC
23
$2,530
$337
SOUTHERN CALIFORNIA GAS COMPANY
4
196
$0
$0
SOUTHERN INDIANA GAS ELECTRIC
4
132
$0
$0
SOUTHERN NATURAL GAS COMPANY
1
73
73
$12,483
$1,661
SOUTHERN STAR CENTRAL GAS PIPELINE
8
599
599
$65,997
$8,782
SOUTHWEST GAS STORAGE COMPANY
4
227
227
$32,769
$4,360
STECKMAN RIDGE LP
1
13
13
$2,223
$296
TENNESSEE GAS PIPELINE COMPANY
52
52
$8,892
$1,183
TEXAS EASTERN TRANSMISSION LP
5
138
134
$33,631
$4,475
TEXAS GAS TRANSMISSION CORPORATION
497
COMPANY
TRANSCONTINENTAL GAS PIPELINE
497
$49,203
$6,547
2
51
51
$14,025
$1,866
TRES PALACIOS GAS STORAGE LLC
1
3
3
$330
$44
TRUNKLINE GAS COMPANY
1
62
$6,138
$817
UGI STORAGE COMPANY
1
3
3
$570
$76
B-6

<<<PAGE 72>>>

Regulatory Impact Analysis: Underground Natural Gas Storage
Appendix B. Operator-level Costs
Exhibit B-2: Estimated Mechanical Integrity Testing Costs per Operator under Regulatory
Compliance Only Baseline Scenario
Total
Operator Name
Number Number
Number Total Costs
Annualized
Fields
of Wells'
of Wells
Tested
(Thousand,
2015$)j
Costs (7%;
015$/Year)3
housand
UNDERGROUND SERVICES MARKHAM LP
1
5
$950
$126
UNDERGROUND STORAGE LLC
1
1
$0
$0
WILD GOOSE STORAGE INC
1
21
$0
$0
WILLISTON BASIN INTERSTATE PIPELINE
2
203
203
$20,097
$2,674
WORSHAM STEED GAS STORAGE LLC
1
57
WYCKOFF GAS STORAGE
1
$0
$0
$0
$0
"Operators for which the number of wells is equal to 0 indicate fields identified in EIA (2016e) but not included in the
TOTAL
16,991
13,682
$1,705,519
$226,942
AGA (2014) inventory.
2 Number of wells tested is less than the total number of wells presented in the column to the left in cases where
wells are already covered under an existing operator commitment or regulated by the state where the facility is
only intrastate fields in states with existing regulatory requirements.
3 Costs may be $0 for certain operators with greater than 0 number of wells in cases where the operator operates
4 Costs annualized using a 7 percent discount rate over 10 years (assuming tests conducted every 10 years).
B-7

## Provenance

- Official: Yes
- Source: <https://downloads.regulations.gov/PHMSA-2016-0016-0005/attachment_1.pdf>
- Source ID: `regulations-gov`
- SHA-256: `985281c8de386117d5f91f2a36eb02699bc0b458a1872cb7388a191d7a981e5d`
- Retrieved: 2026-08-20T02:22:46.679Z
- Exported: 2026-08-25T19:17:11.477Z
- Document slug: `regulations-gov-attachment-090000648242be17`

### Source metadata

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