20250530Amen Exhibit Nos. 34-38.pdf

Preston N. Carter, ISB No. 8462
Megann E. Meier, ISB No. 11948
GIVENS PURSLEY LLP
601 West Bannock Street
P.O. Box 2720
Boise, Idaho 83701-2720
Office: [phone]
Fax: [phone]
[e-mail]
[e-mail]
Attorneys for Intermountain Gas Company
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF THE APPLICATION Case No. INT-G-25-02
OF INTERMOUNTAIN GAS COMPANY
FOR THE AUTHORITY TO INCREASE
ITS RATES AND CHARGES FOR
NATURAL GAS SERVICE IN THE STATE
OF IDAHO
EXHIBIT 34 TO ACCOMPANY THE
DIRECT TESTIMONY OF RON AMEN

ATRIUM ECONOMICS
CENTERED ON ENERGY
Ronald J. Amen
Managing Partner
Mr. Amen has over 40 years of combined experience in utility
management and consulting in the areas of regulatory support,
resource planning, organizational development, distribution
operations and customer service, marketing, and systems EDUCATION
administration. University of Nebraska,
He has advised gas, electric and water utility clients in the Bachelor of Science with
Distinction, Business
following areas: regulatory policy, strategy, and analysis; cost of Administration, Finance
service studies (embedded and marginal cost analyses); rate and Economics
design and pricing issues including time- of-use rates, revenue
decoupling, weather normalization and other cost tracking YEARS EXPERIENCE
mechanisms; resource strategy, planning and financial analysis; 45
and business process design, evaluation, and organizational PROFESSIONAL ASSOCIATIONS
structures. Mr. Amen has provided expert testimony in American Gas Association
numerous state and provincial regulatory agencies, and the Southern Gas Association
Federal Energy Regulatory Commission. Prior to establishing RELEVANT EXPERTISE
Atrium Economics in 2020, Mr. Amen's consulting experience Financial Analysis; Litigation
included Director Advisory & Planning at Black & Veatch Support; Regulatory Support,
Strategy, Utility Operations
Management Consulting, LLC, Vice President of Concentric
Energy Advisors, Inc. and Director with Navigant Consulting, Inc.
His prior utility experience includes leadership of State and
Federal Regulatory Affairs at two electric and gas utilities, and
management positions in Regulatory Affairs, Information Systems and Distribution Operations.
REPRESENTATIVE PROJECT EXPERIENCE
REGULATORY POLICY, STRATEGY AND ANALYSIS
FortisBC Energy, Inc. (2016—2018, 2021-2022)
Performed an overall review of the client's Transportation Service Model. Analyzed the client's
various midstream transportation and storage capacity resources used in providing balancing of
transportation customers' loads. Review included the physical diversity, functionality and
flexibility provided by the various capacity resources, and the cost impact caused by
transportation customers' imbalance levels. Conducted an industry-wide benchmarking study of
current industry-wide best practices, by regulatory jurisdiction, related to transportation
balancing tariff provisions. Participated in stakeholder workshops and testified before the BCUC.
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Retained in 2021 to update quantitative analysis of the operation of the transportation balancing
rules for reporting requirements of the BCUC in 2022.
Western Export Group (2019)
In a Nova Gas Transmission, LTD. (NGTL) Rate Design and Service Application before the Canada
Energy Regulator (CER), Mr. Amen led a consulting team supporting the interests of the Western
Export Group, a group of nine utility companies located in the Western U.S. and British Columbia
who are export shippers on the NGTL system. The case resulted in a settlement with all parties.
Regulatory Commission of Alaska (2019—2020)
Part of a multi-functional team that assisted the Regulatory Commission of Alaska (RCA) in its
evaluation of the Chugach Electric Association, Inc's acquisition of the Municipal of Anchorage
d/b/a Municipal Light & Power Department. Assisted the RCA with its evaluation of the long-term
benefits of the transaction to ML&P and Chugach customers, the implication of terms and
assumptions in various agreements, and the careful balance of the fiscal and regulatory
implications for the customers of the combined entity.
CPS Energy(2017—2018)
Provided an overall review of the client's Strategic Roadmap to prioritize its multi-year regulatory
initiatives. (e.g., changes in product and service offerings, restructuring of current rate classes,
introduction of new rate structures, rate levels, and tariff provisions). Current pricing processes
and platforms were assessed to identify recommended enhancements to enable the
development and implementation of dynamic pricing concepts. Assisted client with preparation
of next rate case (e.g., costing and pricing analyses, load forecasting, internal communications,
and stakeholder engagement).
McDowell Rackner& Gibson Law Firm (2015—2016)
Provided due diligence services to the law firm in connection with a state utility commission
investigation into the law firm client's gas storage and optimization activities. Provided an
independent opinion as to the likely outcome of the Commission's ongoing investigation.
Gulfport Energy Corporation (2016)
Provided regulatory analysis and support to Gulfport Energy Corporation in the ANR Pipeline
Company Natural Gas Act §4 rate proceeding before the Federal Energy Regulatory Commission
(FERC). Analyzed as-filed cost of service and rate design to identify key cost of service, cost
allocation, rate design and service related/tariff issues. Developed an integrated cost of service
and rate design model to prepare studies on client issues. Prepared best/worst case litigation
outcomes, discovery, and evaluations of discovery of other parties. Analyzed FERC staff top
sheets and settlement offers; and assisted in the preparation of settlement positions.
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Confidential Financial / Energy Partners (2015)
Provided regulatory due diligence support for client related to a proposed merger with a
multijurisdictional gas/electric company including an evaluation of the regulatory landscape in
the various applicable state jurisdictions, recent regulatory decisions, and current regulatory
issues.
Confidential International Energy Company (2014)
Provided regulatory due diligence support for client related to a proposed merger with a
multijurisdictional gas company including an evaluation of the regulatory landscape in the
various applicable state jurisdictions, recent regulatory decisions, and current regulatory issues.
Pacific Gas & Electric Company (2014)
Developed an extensive industrywide benchmarking study to determine the cost allocation and
ratemaking treatment utilized by Local Distribution Companies (LDCs) in the United States for
recovery of gas transmission costs. Benchmarked cost allocation and rate design utilized by
Interstate/Intrastate Pipelines. Benchmarked how Industrial & Electric Generation customers are
served with natural gas.
Public Service Company of New Mexico (2009-2010)
Provided case management, revenue requirement, cost of service and rate design support for
general rate cases in the utility's two state regulatory jurisdictions. Issue management and policy
development included an electric fuel and purchased power cost mechanism, recovery of
environmental remediation costs for a coal fired power plant, and the valuation of renewable
energy credits related to a wind power facility.
Confidential International Energy Company (2009)
Provided due diligence on behalf of client related to the purchase of a gas/electric utility,
including a review of the regulatory and market-related assumptions underlying the client's
valuation model, resulting in the validation of the model and identification of key business risks
and opportunities.
RESOURCE PLANNING, STRATEGY AND FINANCIAL ANALYSIS
Manitoba Hydro (2024-2025)
Retained by the client to provide a financial benchmarking framework that will ensure its
financial health, its ability to achieve long-term financial targets, and will support organizational
decision making. Reviewed regulatory jurisdictions in Canada and the U.S. with similarly situated
provincially or publicly owned electric utilities to gain an understanding of how each regulatory
jurisdiction uses financial metrics in rate setting, i.e., which metrics are relied upon and how do
those metrics factor into the determination of authorized rates. Review included at least one
Crown or municipal utility in each Canadian province, U.S. public power hydroelectric utilities,
and opportunistically brought in relevant research from other sectors. Short-listed a group of
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financial metrics used to assess financial health for modeling to test financial outcomes of
metrics and targets for consideration by Executive Team (in progress).
Confidential Multi-Jurisdiction Gas Utility (2021-2022)
Retained by the multi-jurisdiction interstate transmission pipeline and local distribution utility
("client")to assist it in identifying and supporting a natural gas supply solution to satisfy additional
deliverability requirements with the goals of minimizing costs, enhancing system resiliency, and
introducing renewable fuels into its system. Reviewed the process and analyses that had been
conducted to-date (including all underlying assumptions) and provided insight into the best path
forward. The goal of the effort was to help prepare client for internal approval of the process and
recommended path forward, and ultimately the development and approval of the necessary
regulatory filings at the federal, state, and local levels. Atrium evaluated a broad spectrum of
regulatory, economic, market-related, and logistical considerations in order to advise the client on
the best path forward in utilizing LNG to meet its future deliverability requirements. Specific
components of Atrium's analysis included regulatory approvability, rate design and cost recovery
risk, site location (including siting LNG in multiple locations in multiple states), ownership
structure, and ability to incorporate RNG and hydrogen into Utility's system to decarbonize the
pipeline system.
Great Plains Natural Gas (2021-2022)
Retained to review the gas supply procurement practices and objectives of Great Plains, the
interstate pipeline, storage and supply contracts, and other information available to Great Plains
leading up to and throughout the severe weather event that occurred from February 13-17,
2021, and the actions by Great Plains personnel in response to the weather event, as part of a
state-wide investigation by the Minnesota Public Utilities Commission. Expert testimony filed on
behalf of Great Plains.
Fortis BC Energy, Inc. (2011, 2021-2022)
Retained to help develop a gas supply incentive mechanism in cooperation with the British
Columbia Utilities Commission staff and the company's other stakeholders. Provided an
independent analysis of the utility's management of pipeline and storage capacity and supply.
Part of this work entailed a review of the major markets in which the utility transacted, reviewing
the size of trading activity at the major market hubs and reviewing the price indices for these
markets. In 2021, retained to refresh all quantitative analysis of the operation of the GSMIP for
reporting requirements of the BCUC in 2022.
Black Hills Colorado Electric Utility(2009)
Engaged as a member of a consultant team that served as the independent evaluator in a
competitive solicitation for non-intermittent generation resources. Jointly recommended by the
utility client, the staff of the utility commission and the state attorney general, the consulting
team acted as an agent of the public utility commission monitoring and overseeing the
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solicitation, which included reviewing the request for proposals and solicitation process,
including provisions of the power purchase agreement, preliminary review (economic and
contractual) of bids received from the request for proposals, initial modeling of bids for
screening, selection of bidders with whom to conduct negotiations and oversight of the
negotiation process, and the ultimate selection of the winning bid. Provided due diligence review
of all input data, preliminary and final model output, and output summaries. The team produced
biweekly confidential reports to the commission regarding the process and its results.
NW Natural (2007-2008)
Assisted with the development of its long-term Integrated Resource Plan (IRP) for its Oregon and
Washington service territories. The IRP included the evaluation of incremental inter- and intra-
state pipeline capacity, underground storage, and two proposed LNG plants under development
in the region.
Puget Sound Energy(2007)
Engaged to assist the client with the development of a natural gas resource efficiency and direct
end-use strategy, an interdepartmental initiative focused on preparing a natural gas resource
efficiency plan that optimizes customers' end-use energy consumption while furthering
corporate customer, financial, environmental, and social responsibilities.
Puget Sound Energy(2002—2003)
Provided resource planning strategy and analysis for the company's Least Cost Plan, including a
review of the company's underlying 20-year electric and gas demand forecasts. As a member of
a consulting team, served as the client's financial advisor for the acquisition of new electric
power supply resources. Conducted a multitrack solicitation process for evaluation of generation
assets and purchase power agreements. Provided regulatory support for the acquisition.
COST ALLOCATION, PRICING ISSUES AND RATE DESIGN
Philadelphia Gas Works PGW (2023, 2024-2025)
Mr. Amen led an Atrium team engaged by PGW to review the mechanics, input data, billing
controls, and weather trends surrounding PGW's Weather Normalization Adjustment ("WNA")
formula to understand the factors that contributed to the abnormally high WNA charges in June
2022. Atrium's review identified structural factors inherent in PGW's WNA mechanism that may
have contributed to the anomalous WNA amounts billed to customers in June 2022. Mr. Amen
filed testimony with Atrium's findings and recommendation in the pending general rate case
before the Pennsylvania Public Utility Commission. Mr. Amen provided expert testimony in
PGW's 2024 general rate proceeding supporting the continuation of the WNA, supplemented by
the addition of a Revenue Normalization Adjustment ("RNA") mechanism. (Case pending)
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Public Service Company of Colorado (Xcel) (2024)
Mr. Amen was engaged to provide expert testimony presenting and supporting the Company's
proposed Revenue Stability Mechanism ("RSM"). The RSM is a total revenue decoupling
mechanism intended to separate the Company's revenue from the volume of gas it sells to help
support Colorado's state decarbonization goals. The Colorado Senate Bill 21-264 directed gas
utilities to submit "Clean Heat Plans" to reduce carbon dioxide and methane emissions toward
Clean Heat targets in specific years. Potential emissions reduction measures include energy
efficiency, biomethane, hydrogen, recovered methane, beneficial electrification of customer end
users, and leak detection, among others.
Potomac Electric Power Company(PEPCO) (2022-2023)
Mr. Amen led an Atrium team engaged by PEPCO on behalf of services requested by the Public
Service Commission of the District of Columbia ("DC Commission"), for comprehensive
evaluation of the processes, procedures, mechanics, and internal controls surrounding PEPCO's
Bill Stabilization Adjustment ("BSA"). Atrium provided independent audit services sought by the
DC Commission, including a) independently evaluate the timing, impact and magnitude of the
billing determinant error that was identified during Formal Case No. 1156; b) independently
confirm that current BSA processes and procedures are properly and timely executed as
designed; c) independently confirm that current Pepco BSA internal controls are properly and
timely executed; d) independently identify any recommended process and procedural
improvements, as well as any recommended changes in existing internal controls or new internal
controls; and e) independently conduct a comprehensive review of Pepco's BSA deferral balances
by customer class, with an overall determination of the breakdown of BSA deferral balances by
key drivers for each customer class. Our audit report and recommendations were filed with the
DC Commission in July 2023.
Summit Natural Gas of Maine, Inc. (2022 - 2023)
Mr. Amen provided revenue requirement, allocated cost of service, class revenue
apportionment, rate design, and expert witness testimony support for the utility's gas general
rate case and multi-year rate plan before the Maine Public Utilities Commission. Responsibilities
included determination of an optimal normal weather period for purposes of normalizing test
year billing determinants, followed by the weather normalization process of determining a
representative level of gas throughput for the Company's test year. The case resulted in an all-
party settlement before the Maine PUC.
Black Hills Energy Arkansas (2021-2022, 2023-2024)
Mr. Amen provided allocated cost of service, class revenue apportionment, rate design for
natural gas infrastructure mechanisms, and expert witness support for two of the utility's gas
general rate case before the Arkansas Public Service Commission. The cases resulted in
settlements before the Arkansas PSC.
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Until Electric System, Northern Utilities, Fitchburg Gas & Electric (2021-2022, 2023-2024)
Mr. Amen provided allocated cost of service ("ACOSS"), marginal cost of service, class revenue
apportionment, rate design, and expert witness support for the utility's separate electric and gas
general rate cases before the New Hampshire Public Utilities Commission, including expert
witness testimony. The cases resulted in settlements before the NHPUC.
For Until affiliate, Fitchburg Gas & Electric, Mr. Amen conducted an ACOSS to determine the
embedded costs of serving the Company's gas distribution customers and support its rate design
efforts in its base distribution rate proceeding before the Massachusetts Department of Public
Utilities. Sponsored expert witness support for the ACOSS, class revenue apportionment,
proposed rate design, and bill impacts. Also sponsored the weather normalization and
annualization of its billing determinants and a Marginal Cost of Service Study.
Manitoba Hydro—Centra Gas Manitoba (2021-2022)
Retained to provide an independent review of the cost of service methodologies employed for
Centra Gas Manitoba Inc.'s natural gas operations. Atrium prepared a report filed with the
Manitoba Public Utility Board documenting and supporting our assessment of Centra's existing
COSS methods in conformance with the regulatory requirements of the MPUB. Focusing on the
trends of Canadian gas distribution utilities, the COSS method utilized in the current COSS was
reviewed against the: (1) cost causative factors identified for each plant and expense element of
Centra's total cost of service; and (2) the current range of regulatory practices observed in the
North American gas utility market. Centra's 2022 rate application based on the
recommendations in our report was approved by the MPUB.
Montana-Dakota Utilities and Great Plains Natural Gas (2020—2021, 2022—2023, 2024-2025)
Mr. Amen provided cost of service, class revenue apportionment, rate design, and expert witness
support for the gas utilities' general rate cases before the Montana Public Service Commission
(MPSC) and North Dakota Public Service Commission (NDPSC). Testimony included theoretical
principals and practical application of cost allocation, and rate design principles or objectives that
have broad acceptance in utility regulatory and policy literature. Supported the Straight Fixed-
Variable Rate Design (SFV) in North Dakota with analysis showing low-income residential
customers would experience lower annual bills under the SFV rate design than a volumetric
weighted rate design. Provided a presentation at a public input hearing and oral testimony at
Commission hearings in both jurisdictions. SFV rate design was approved by the North Dakota
PSC. The cases resulted in settlements approved by the respective Commissions.
Mr. Amen also represented the client's interests (as well as those of neighboring utility clients
NW Natural and Puget Sound Energy) in a Washington generic rulemaking proceeding on the
subject of electric and gas cost of service methodologies and minimum filing requirements.
Mr. Amen supported MDU electric general rate case filings in Montana and North Dakota (2022),
including a marginal cost study in Montana, and allocated cost studies, revenue apportionment
and rate design in both jurisdictions.
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Mr. Amen recently supported gas general rate case filings in MDU's Idaho affiliate, Intermountain
Gas (2022-2023) and Washington affiliate, Cascade Natural Gas (2024). Testimony support
included a class level, design day load studies across the two utilities' temperature zones, using a
combination of AMI penetration and monthly billing data, class allocated cost of service study,
class revenue apportionment, and rate design.
Mr. Amen supported gas and electric general rate case filings in MDU's South Dakota service
territory (2023), including gas and electric allocated cost studies, revenue apportionment and
rate design, and are currently supporting MDU gas cases in Montana and Wyoming ( both filed
August 2024).
Chesapeake Utilities Corporation (2020—2021, 2024-2025)
Reviewed and evaluated Chesapeake's Swing Service Rider (SSR), which recovers intrastate
pipeline capacity costs directly from all transportation customers, and the application of the
current cost allocation methodology underlying the service for its Florida gas utilities, Central
Florida Gas and Florida Public Utilities. Supported Chesapeake through three primary tasks; (1)
Assessment of the factors influencing the current cost allocation method, its impact on various
customer groups, and data collection, (2) Assessment of the appropriateness of alternative cost
allocation methods and model the application to and impact on the SSR charges, and (3)
Provided a report of the evaluation, modelling results and recommendations in a report and
conducted a review session with Chesapeake management personnel.
Mr. Amen is currently providing testimony support for Chesapeake Utility's Delaware general
rate case (filed August 2024), including a Lead Lag study supporting cash working capital,
determination of normal weather, cost of service and rate design principles, allocated cost of
service results, revenue apportionment, and a modified version of a prior weather normalization
adjustment (WNA) rider.
Kansas City, KS Board of Public Utilities (2019—2020)
Provided expert witness testimony supporting the basis for a Green Energy Program, its
objectives, and overall benefits. Provide an assessment of how the program is aligned with best
practices in design of Green Energy tariff programs nationally. Testimony also provided an
assessment of how the program mitigates potential risks to the Board of Public Utilities and
protects against subsidization of other rate classes.
NW Natural (2018—2019)
Provided cost of service, class revenue apportionment, rate design, and expert witness support
for the gas utility's general rate case before the Washington Utility and Transportation
Commission (WUTC), filed in December 2018. Testimony included theoretical principals and
practical application of cost allocation, and rate design principles or objectives that have broad
acceptance in utility regulatory and policy literature.
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Chesapeake Utilities Corporation (2018—2019)
Developed a Weather Normalization Adjustment (WNA) mechanism applicable to the monthly
billings of Chesapeake's residential and general service customers. Sponsored the WNA
mechanism through expert testimony filed with the Delaware Public Service Commission in
January 2019. The testimony included a description of the WNA calculations; back-casting
performance analyses, with bill impacts; a WNA tariff; and conceptual and evidentiary support
for this ratemaking mechanism.
Louisville Gas & Electric Company and Kentucky Utilities Company (2018)
Engaged by LG&E and KU to conduct a study in support of a joint utility and stakeholder
collaborative concerning economical deployment of electric bus infrastructure by the transit
authorities in the Louisville and Lexington KY areas, as well as possible cost-based rate structures
related to charging stations and other infrastructure needed for electric buses.
Summit Utilities—Colorado Natural Gas, Inc. (2018)
Engaged by Summit Utilities to develop and support with expert testimony an appropriate
normal weather period for the client's five Colorado temperature zones, resulting normalized
billing determinants, and a Weather Normalization Adjustment ("WNA") proposal in conjunction
with the filing of a general rate case for its Colorado Natural Gas, Inc. subsidiary.
Westar Energy (2018)
Provided cost of service and expert witness support for the electric utility's general rate case
filing before the Kansas Corporation Commission (KCC). The cost of service study determined the
cost components for a new Residential Distributed Generation (DG) customer class that provided
the basis for recommendations for establishing components of a sound, modern three-part rate
design for this new Residential DG (roof-top solar) service, which was approved by the KCC.
Florida Public Utilities (Chesapeake Utilities) (2017—2018)
Provided a rate stratification study of the utility's commercial and industrial customer classes to
facilitate the reconfiguration of the classes by size of service facilities, annual volume, and load
factor. Reviewed the cost allocation bases and recommended alternatives for recovery of capital
investments related to the utility's Gas Reliability Investment Program (GRIP).
Tacoma Power(2016—2018, 2023, 2024- 2025)
Provided cost of service and rate design support for the electric utility's general rate case filings,
including support for recovery of fixed costs through fixed charges and impacts on low income
customers. Provided recommendations as to specifications in the client's cost of service analysis
(COSA) model for deriving Open Access Transmission Tariff rates, using FERC approved standards
to guide the evaluation. Conducted an electric utility costing and pricing workshop for the PUB in
October 2017; and participated with Tacoma Utilities staff in a comprehensive electric and water
Rates and Financial Planning workshop in February 2018. Engagement was extended for the 2019
—2020 rate filing, which incorporated the Black &Veatch municipal COSA model for costing and
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ratemaking purposes. Currently providing cost of service and rate design for the 2023—2024 rate
filing. Ongoing work involves innovative rate programs and demand forecasting.
Tacoma Power(2017)
Engaged to review and assess current rates for 3rd Party Pole Attachments (PA), and more
specifically, to determine and recommend if any rate adjustments were needed. Performed
several tasks:
• Performed a market survey of rates charged by comparable utilities.
• Reviewed current regulations on rate setting and practice for 3rd Party Pole
Attachments as set forth by the Federal Communications Commission (FCC) and
the State of Washington (WA), and the interpretation of such regulations in court
decisions.
• Reviewed industry best practices under the FCC, WA, and the American Public
PowerAssociation (APPA)
• Collected and reviewed data for cost-based fees including:
• Application Fees
• Non-Compliance Fees
• Reviewed cost data supplied by the City of Tacoma related to determining pole
costs,and
• Performed modeling of rates under the FCC Model,the APPA model, and the State
ofWashington shared model (50% FCC Rate/50%APPA Rate).
BC Hydro (2016)
Provided research and analysis of the line extension policies of a select group of peer utilities in
Canada with similar regulatory regimes as well as U.S. utilities based on their geographic
relationship to the client. Conducted interviews with peer utilities to gather comparative
information regarding their line extension policies and related internal procedures. Performed a
comparative analysis of the various line extension policies from the selected peer group.
Cascade Natural Gas Corporation (2015—2019)
Provided cost of service and rate design support for several of the company's general rate case
filings in its two state jurisdictions, 3 in Oregon and 2 in Washington. Conducted Long-run
Incremental Cost Studies in the Oregon jurisdiction and embedded class allocated cost of service
studies in the Washington jurisdiction. Performed benchmark analyses to compare each of the
client's administrative and general (A&G) and operations and management (O&M) expenses, on
a per-customer basis, to various peer groups. Analyses were performed for natural gas utilities
and combination utilities with both electric and gas operations. Various iterations of the analyses
were prepared to make the peer group of utilities more comparable to the characteristics of the
client's utility operations. Represented the client's interests in a Washington generic rulemaking
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proceeding on the subject of electric and gas cost of service methodologies and minimum filing
requirements.
Chesapeake Utilities (2015—2016)
For its Delaware jurisdiction, provided cost of service and rate design support in the client's
general rate case proceeding, including expert witness testimony in support of the utility's
proposed gas revenue decoupling mechanism.
Homer Electric Association/Alaska Electric and Energy Cooperatives (2015)
Represented clients in an ENSTAR gas general rate proceeding. Testimony discussed accepted
industry principles of revenue allocation and rate design, including the applicability to and
alignment with ENSTAR's revenue allocation and rate design proposals for large power and
industrial customers. Provided a critique of certain methodological aspects of ENSTAR's Cost of
Service study, proposed revenue allocation, and rate design relating to the various large power
and industrial customers.
Arkansas Oklahoma Gas Corporation (2002, 2003, 2004, 2007, 2012, 2013)
Provided cost of service and rate design support for several of the company's general rate case
filings in its two state jurisdictions and in support of Section 311 transportation filings (2007,
2010) before the Federal Energy Regulatory Commission. Provided related research, design, and
expert witness testimony in support of a Revenue Decoupling mechanism in one jurisdiction and
a Weather Normalization Adjustment mechanism in the other jurisdiction, along with a
significant increase in fixed charges and the introduction of demand charges for the company's
largest customer classes. Conducted a pre-filing "decoupling" workshop for the utility
commission staff.
Northern Indiana Public Service Company (NiSource) (2009—2010, 2013, 2017, 2021)
Conducted class allocated cost of service studies for the client's natural gas (including two other
affiliate gas utilities) and electric operations. Work included reconfiguring the Company's
commercial and industrial customer classes according to size of load and customer-related
facilities. Rate design was modernized to recover a greater portion of fixed costs via fixed
monthly customer and demand-based charges, a transition to a "Straight-Fixed Variable" form of
rate design. Industry research was provided on alternative rate designs for the electric service,
including Time-of-Use rates and Critical Peak Pricing. Served as an expert witness on behalf of the
client in five general rate cases before the Indiana Utility Regulatory Commission. The 2021 rate
case is currently pending before the IURC.
Southwestern Public Service Company (Xcel) (2012)
Retained to conduct a study to estimate the conservation effect of replacing its existing electric
residential rate design with an alternative rate design such as an inverted block rate design.
Reviewed inclining block rate structures that have actively been employed in other jurisdictions
and also reviewed technical and academic literature to assess the elasticity of electricity demand
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for residential customers in the southwestern U.S. Analyzed 2009-2011 residential data to
determine what sort of conservation effect the company may expect by implementing an
inclining block rate structure. Provided an overview of alternative rate structures which may also
promote conservation effects, such as seasonal rates, three-part rates, and time-of-use (TOU)
rates, and considered the competing incentives of promoting conservation and cost recovery,
without specific rate mechanisms to address this conflict.
Atlantic Wallboard LP and Flakeboard Company Limited (JD Irving) (2012)
Represented clients in an Enbridge Gas New Brunswick Limited Partnership ("EGNB") general
rate proceeding. Testimony responded to the 2012 allocated cost of service study and rate
design that was submitted to the New Brunswick Energy and Utilities Board by EGNB. Testimony
also provided benchmark information regarding EGNB's distribution pipeline infrastructure in
New Brunswick. CA.
Western Massachusetts Electric Company(Northeast Utilities) (2010—2011)
Supported utility in its decoupling proposal for the company's general rate case. Work included:
1) research on the financial implications of decoupling; 2) identification of decoupling mechanism
details to address company and regulatory requirements and objectives; 3) identification of rate
adjustment mechanisms that would work together with the company's proposed decoupling
mechanism; and 4) preparing pre-filed testimony and testifying at hearings in support of the
company's decoupling and rate adjustment proposals. The proposed rate adjustment
mechanisms included an inflation adjustment mechanism based on a statistical analysis, and a
capital spending mechanism to recover the costs associated with capital plant investment
targeted to improving service reliability.
Interstate Power& Light (Alliant Energy) (2010—2011)
Conducted class allocated cost of service studies for a Midwestern electric utility's Minnesota
electric system. Work included reconfiguring the company's customer classes for cost of service
purposes to collapse end-use based classes with the classes to which they would be eligible. Cost
of service studies were performed on a before-and-after basis for the existing and proposed
classes. The cost of service studies included a fixed/variable study for production costs, and a
primary/secondary study for poles, transformers, and conductors. Performed a TOU analysis to
determine the appropriate rate differentials for its peak and off-peak rates. Served as an expert
witness on behalf of the client in a general rate case before the Minnesota Public Service
Commission.
National Grid (2010)
Conducted class allocated cost of service studies for the client's Massachusetts natural gas
operations. This task included combined gas cost of service studies for the consolidation of four
gas service territories into two gas utility subsidiaries. During interrogatories, performed four
separate allocated cost of service studies for each gas service territory. Work included
reconfiguring the company's commercial and industrial customer classes according to size of load
Case No.INT P jS_- 42
R.Amen,IGC
Exhibit No. 34
Page 12 of 16

Resume of Ronald J. Amen
and customer-related facilities. Served as an expert witness on behalf of the client in
consolidated general rate cases before the Massachusetts Department of Public Utilities.
Puget Sound Energy(2001—2002, 2006—2007, 2019—2020)
In three Washington general rate proceedings, provided cost of service and rate design support,
including expert witness testimony in support of the utility's proposed revenue decoupling
mechanism. Conducted research on accelerated cost recovery mechanisms for infrastructure
replacement, and electric power cost adjustment mechanisms. In the latest general rate case,
Mr. Amen sponsored expert testimony on a proposed revenue attrition adjustment to the
client's revenue requirement in the 2020 general rate case.
UTILITY SYSTEM OPERATIONS AND ORGANIZATIONAL DEVELOPMENT
Philadelphia Gas Works (2017, 2020)
Engaged to provide an independent consulting engineer's report to be included as an appendix
to the official statement prepared in connection with the issuance of the City of Philadelphia,
Pennsylvania Gas Works Revenue Bonds. The evaluation of the PGW system included a
discussion of organization, management, and staffing; system service area; supply facilities;
distribution facilities; and the utility's Capital Improvement Plan (CIP). Our report also contained:
(a) financial feasibility information, including analyses of gas rates and rate methodology; (b)
projection of future operation and maintenance expenses; (c) CIP financing plans; (d) projection
of revenue requirements as a determinant of future revenues; (e) an assessment of PGW's ability
to satisfy the covenants in the General Gas Works Revenue Bond Ordinance of 1998 authorizing
the issuance of the Bonds; and (f) information regarding potential liquefied natural gas ("LNG")
expansion opportunities.
Puget Sound Energy(2013—2014)
Engaged to perform a review of its project management and capital spending authorization
processes (CSA). The overall project objectives were to educate project management (PM) staff
as to the importance and relevance of regulatory prudence standards, evaluate existing PM
processes along with newly introduced corporate CSA processes, and propose PM and corporate
process and documentation efficiencies. This task was accomplished through 1) a situational
assessment and risk review; 2) analysis of project management practices; and 3) development of
common documentation for the CSA and PM processes.
Puget Sound Energy(2012—2013)
Engaged to perform a review of how the company compares to similarly situated utilities in the
areas of the underlying capitalized costs related to new customer additions ("new business
investment") and the management policies and practices that influence the new business capital
investment. Examined the interrelationships of our client's management policies and practices in
the functional areas related to new business investment and developed an understanding of the
nature of the costs captured by the new business investment process. Benchmarked those costs
Case No.INT P( je5-643
R.Amen,IGC
Exhibit No. 34
Page 13 of 16

Resume of Ronald J. Amen
relative to peers' cost factors and management capital expenditure practices and performed
targeted peer group interviews on our client's behalf. The review identified certain trends and/or
interrelationships between management policies and practices, as well as other exogenous
factors, and the resulting impact on new business investment.
Puget Sound Energy(2011—2012)
Engaged to perform a review of its electric transmission planning and project prioritization
process. The emphasis of the review was to determine if the process implemented by the client
could be expected to meet the regulatory standard of prudence, as adopted by the state
regulatory commission. Reviewed the prudence standard adopted by the commission in several
recent regulatory proceedings, supplemented by our knowledge of the prudence standard
adopted at a national level and in other states. The engagement included two phases: 1) an initial
situation assessment of the existing process employed by the client, and 2) a review of the
historic implementation of that process by reviewing a sampling of transmission projects.
Compiled and provided examples of capital planning documents and procedures, viewed as "best
practices," from other electric utilities and other relevant transmission entities.
Alliant Energy (2011—2012)
Provided audit support for one of the company's gas and electric utilities, Interstate Power &
Light, during a management audit ordered by one of its two regulatory jurisdictions. Conducted a
pre-audit of distribution operations and resource planning processes to provide the client with
potential audit issues. Assisted the client throughout the audit process in responding to
information requests, preparing company executives and management personnel for audit
interviews, and management of preliminary audit issues and findings by the independent audit
firm.
Ameren Illinois Utilities (2009—2010)
Performed a number of benchmark analyses to compare each of the client's A&G and O&M
expenses, on a per-customer basis, to various peer groups conducted for the client's natural gas
and electric operations. Analyses were performed for natural gas, electric and combination
utilities with both electric and gas operations. Various iterations of the analyses were prepared
to make the peer group of utilities more comparable to the characteristics of the client's utility
operations. Served as an expert witness on behalf of the client in a consolidated general rate
case proceeding of its three utility subsidiaries before the Illinois Commerce Commission.
Case No.INT P( jS_- 44
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Exhibit No. 34
Page 14 of 16

Resume of Ronald J. Amen
EXPERT WITNESS TESTIMONY PRESENTATION
• Alaska Regulatory Commission
• Arkansas Public Service Commission
• British Columbia Utility Commission (Canada)
• Colorado Public Utility Commission
• Connecticut Department of Public Utility Control
• Delaware Public Service Commission
• Illinois Commerce Commission
• Idaho Public Utilities Commission
• Indiana Utility Regulatory Commission
• Kansas Corporation Commission
• Kentucky Public Service Commission
• Maine Public Utilities Commission
• Manitoba Public Utilities Board (Canada)
• Massachusetts Department of Utilities
• Minnesota Public Utilities Commission
• Missouri Public Service Commission
• Montana Public Service Commission
• New Brunswick Energy and Utilities Board (Canada)
• New Hampshire Public Utilities Commission
• North Dakota Public Service Commission
• Oklahoma Corporation Commission
• Oregon Public Utility Commission
• Pennsylvania Public Utility Commission
• South Dakota Public Utilities Commission
• Washington Utilities and Transportation Commission
• Wyoming Public Service Commission
• Federal Energy Regulatory Commission
�\ Case No.INT P( B-05
G R.Amen,IGC
Exhibit No. 34
Page 15 of 16

Resume of Ronald J. Amen
SELECTED PUBLICATIONS / PRESENTATIONS
"Enhancing the Profitability of Growth," American Gas Association, Rate and Regulatory Issues
Seminar, April 4 - 7, 2004
"Regulatory Treatment of New Generation Resource Acquisition: Key Aspects of Resource
Policy, Procurement and New Resource Acquisition," Law Seminars International, Managing
the Modern Utility Rate Case, February 17 - 18, 2005
"Managing Regulatory Risk—The Risk Associated with Uncertain Regulatory Outcomes,"
Western Energy Institute, Spring Energy Management Meeting, May 18 - 20, 2005
"Capital Asset Optimization—An Integrated Approach to Optimizing Utilization and Return on
Utility Assets," Southern Gas Association, July 18 - 20, 2005
"Resource Planning as a Cost Recovery Tool," Law Seminars International, Utility Rate Case
Issues & Strategies, February 22 - 23, 2007
"Natural Gas Infrastructure Development and Regulatory Challenges," Southeastern
Association of Regulatory Utility Commissioners, Annual Conference,June 4—6, 2007
"Resource Planning in a Changing Regulatory Environment," Law Seminars International,
Utility Rate Cases—Current Issues & Strategies, February 7 - 8, 2008
"Natural Gas Distribution Infrastructure Replacement," American Gas Association, Rate
Committee Meeting and Regulatory Issues Seminar, April 11- 13, 2010
"Building a T&D Investment Program to Satisfy Customers, Regulators and Shareholders," SNL
Webinar, March 27, 2014
"Utility Infrastructure Replacement; Trends in Aging Infrastructure, Replacement Programs
and Rate Treatment," Large Public Power Council, Rates Committee Meeting, August 14, 2014
"Natural Gas in the Decarbonization Era, Gas Resource Planning for Electric Generation," EUCI,
January 22-23, 2020
012%G Case No.INT P( je5-646 R.Amen,IGC
Exhibit No. 34
Page 16 of 16

Preston N. Carter, ISB No. 8462
Megann E. Meier, ISB No. 11948
GIVENS PURSLEY LLP
601 West Bannock Street
P.O. Box 2720
Boise, Idaho 83701-2720
Office: [phone]
Fax: [phone]
[e-mail]
[e-mail]
Attorneys for Intermountain Gas Company
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF THE APPLICATION Case No. INT-G-25-02
OF INTERMOUNTAIN GAS COMPANY
FOR THE AUTHORITY TO INCREASE
ITS RATES AND CHARGES FOR
NATURAL GAS SERVICE IN THE STATE
OF IDAHO
EXHIBIT 35 TO ACCOMPANY THE
DIRECT TESTIMONY OF RON AMEN

Cost of Service Allocation Study
Table of Contents
I. INTRODUCTION ....................................................................................................................... 1
1. Purpose of Cost Allocation.............................................................................................. 1
2. COSS Procedures............................................................................................................. 1
3. Atrium Economics Cost of Service Study Model Overview ............................................ 2
II. INTERMOUNTAIN'S COST OF SERVICE PROCEDURES .............................................................4
1. Functionalization............................................................................................................. 4
2. Classification ...................................................................................................................4
3. Allocation ........................................................................................................................4
3.1. Customer Classes and Tariff Schedules ...................................................................... 4
3.2. External Allocation Factors......................................................................................... 5
3.3. Mains Analysis............................................................................................................. 7
3.4. Internal Allocation Factors.......................................................................................... 8
III. INTERMOUNTAIN'S COST OF SERVICE RESULTS ................................................................... 10
Schedule 1 -Account Balances and Allocation Methods...................................................... 11
Schedule 2 - External Allocation Factors............................................................................... 18
Schedule 3 - Internal Allocation Factors................................................................................ 19
Schedule 4 - Cost of Service and Rate of Return Under Present and Proposed Rates......... 20
Schedule 5 - Cost of Service Allocation Study Detail by Account.......................................... 22
Schedule 6 - Functionalized and Classified Rate Base and Revenue Requirement, and Unit
Costs by Customer Class........................................................................................................ 29
Table of Contents i
vI Case No. INT-G-25-02
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Exhibit No. 35
Page 1 of 32

Cost of Service Allocation Study
Page 1
I. INTRODUCTION
The purpose of this document is to discuss the development and results of the Cost of Service
Study ("COSS") model and related schedules prepared for Intermountain Gas Company
("Intermountain" or the "Company") based on the Test Year ended December 31, 2024 ("Test
Year") with pro forma adjustments for 2025.
The document is organized into three sections. The first section includes an overview of
Atrium's COSS model used to develop the cost allocation study. The second section includes
details of the methodologies adopted in the development of the study. The last section
exhibits the results of the COSS study.
1. Purpose of Cost Allocation
The purpose of a COSS is to determine the cost-of-service responsibilities of each customer
class upon which the base rates may be established. The revenue requirement studies provide
the overall level of costs of providing service, while the COSS is used to change the basic rate
structures and/or the relative overall cost responsibility of each customer class. Based on the
functionalization and classification of costs and allocation methodologies used in the COSS, the
revenue requirement by customer class is determined and used in designing the Company's
proposed base rates. In other words, the COSS measures each class's contribution to the
Company's overall cost of service. Comparing the costs to serve any customer class with that
class's rate revenues provides a measure of the return realized from that class and their
associated revenue-to-cost ratio. This allows for a comparison across classes to ascertain the
presence and extent of interclass subsidization (i.e., when one class pays more than its cost to
serve, and another pays less than its cost to serve).
2. COSS Procedures
Cost of service studies utilize a three-step process: functionalization, classification, and
allocation.
In the first step, the functionalization sets off with assigning the Federal Energy Regulatory
Commission ("FERC") plant accounts and associated investment balances to appropriate cost of
service functions, such as Storage, Transmission, Distribution, On-Site and Metering, Customer
Accounts and Service, and Gas Supply. The expenses related to particular property investments
or groups of investments can often follow the same functionalization and are allocated based
on the ratios of gas plant assigned to each function. These plant ratios can be used to
functionalize most other cost items.
INTRODUCTION
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Exhibit No. 35
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Cost of Service Allocation Study
Page 2
In the second step, classification, each functional cost category is further separated by cost
causation. There are three basic cost-defining characteristics of natural gas services: demand,
commodity, and customer.
• Demand (Capacity) related costs are associated with the peak usage of the utility system.
These costs are necessary to maintain the system at a level sufficient to satisfy the greatest
demand that all the customers could place upon the system.
• Commodity-related costs are variable costs that vary with the quantity of gas consumed.
These costs reflect the number of units consumed or supplied during a period of time.
• Customer-related costs are associated with serving customers regardless of their usage or
demand characteristics. Customer-related costs are incurred to attach a customer to the
distribution system, meter any gas usage and maintain the customer's account. Customer
costs are a function of the number of customers served and continue to be incurred
whether or not the customer uses any gas. They generally include capital costs associated
with minimum size distribution mains, services, meters, regulators and customer service
and accounting expenses.
The last step is to allocate these cost components among customer classes. The development
of allocation factors by customer class uses principles of both economics and engineering. This
results in appropriate allocation factors for different elements of costs based on cost causation.
3. Atrium Economics Cost of Service Study Model Overview
The Cost of Service Study is submitted in support of the direct testimony of Ronald J. Amen in
Exhibit 35. The COSS model presented in this proceeding is an excel based model that allows
the user to modify various inputs and assumptions.
COSS Model Capabilities
The Atrium Economics' COSS model provides a large range of analytical capabilities including:
• Unbundling of operations into functions: (i.e., production/supply, storage, transmission,
distribution, metering, and billing services.)
• Classification and allocation of costs into customer classes.
• Reports on Rate of Return, Revenue Requirement, and Revenue-to-Cost ratio for each
function and rate class.
• Development of unit costs of each functional classification for each rate class.
• Specification of the individual rate of return targets for each function or customer class.
• Provides detailed analyses of costs of gas, income taxes, working capital, depreciation
reserve, and depreciation expenses.
INTRODUCTION
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Exhibit No. 35
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Cost of Service Allocation Study
Page 3
• Use of detailed analysis of labor expenses by account to facilitate the analyses of
administrative and general expenses and overhead costs.
• Facilitation of direct assignment of plant investment, expenses, and revenue dollars to
individual functions, classifications, or customer classes.
Follows Traditional 3-Step Analysis Process
The Atrium COSS Model follows the standard three-step analysis process:1) functionalization of
rate base and expenses into various functional categories; 2) classification of functionalized
components into demand, energy/commodity, and customer cost categories; and 3) allocation
of each component among the customer classes.
As part of the functionalization process, accounts for common costs that are not specifically
related to the primary functions, such as general plant and administrative and general
expenses, are automatically allocated to the proper function based on internally defined
allocation factors. All components of the utility's total cost of service are grouped into one of
the functions.
The Atrium COSS Model provides unbundled functionalized and classified cost information by
customer class; develops unbundled revenue requirements by functional classification for each
customer class; and calculates unit costs by function for customer, commodity, and demand
categories. Accounting costs are reported by FERC account level, and the allocation of A&G
expenses, general taxes, and income taxes are clearly reported.
Revenue requirements are calculated from the allocated rate base and expenses and are
adjusted to reflect the user-determined target rate of return and statutory tax adjustments.
The actual revenues collected are compared to the calculated cost-based revenue requirements
to determine class-specific, revenue-to-cost ratios to assist in revenue allocation and pricing
activities.
Unit Cost Output Functionality
The COSS model calculates the unit cost of each functional classification separately for each
rate class based on the user-specified billing determinants. These unit cost data are among the
most important outputs from an embedded cost of service analysis. They are defined as the
average cost of providing service to customers per measure of service (i.e., per therm, per
dekatherm of daily demand, and per customer). Unit costs are a key consideration in
developing prices for bundled, unbundled, and re-bundled services.
Acceptance by Utility Regulatory Commissions
The format and presentation of the model's outputs have been used in many rate case
proceedings and conform to standard utility commission requirements. Where necessary, the
COSS model outputs can be easily modified to meet specific jurisdictional filing requirements.
INTRODUCTION
\/ Case No.INT-G-25-02
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Exhibit No. 35
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Cost of Service Allocation Study
Page 4
II. INTERMOUNTAIN'S COST OF SERVICE
PROCEDURES
1. Functionalization
The following functional cost categories were identified for purposes of Intermountain's cost
allocation:
• Storage
• Transmission
• Distribution
• General (Customer)
Intermountain's assigned functional categories are presented on Schedule 1.
2. Classification
The following classification categories were identified for purposes of Intermountain's cost
allocation:
• Demand
• Customer
Intermountain's assigned classification categories are presented on Schedule 1.
3. Allocation
The allocation step involves assigning classified costs to the customer classes based on cost
causation. Therefore, the allocation of costs is usually based on some measure of class loads or
class service characteristics. The External (Schedule 2) and Internal (Schedule 3) Allocation
Factors are utilized to allocate costs among various customer classes. Intermountain's assigned
Allocation Factors are presented on Schedule 1.
3.1. Customer Classes and Tariff Schedules
The following customer classes were identified for purposes of cost allocation:
• Residential Service
• General Service
• Large Volume
• Transport Service (Interruptible)
• Transport Service (Firm)
INTERMOUNTAIN'S COST OF SERVICE PROCEDURES
\/ Case No.INT-G-25-02
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Exhibit No. 35
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Cost of Service Allocation Study
Page 5
3.2. External Allocation Factors
Intermountain's External Allocation Factors are presented on Schedule 2. The External
Allocation Factors are developed based on the special studies conducted using various detailed
data as discussed below.
Commodity and Revenue Allocation Factors
Costs classified as "Commodity" are allocated among customer classes based on the weather-
normalized volumes for the test year.
Allocation Factor Description
REV Factor developed to directly assign associated current base rate
revenues to the specific class in the Test Year.
COM Factor developed to directly assign Weather Normalized
Volumes/Throughput to the specific class in the Test Year.
Customer Allocation Factors
Customer-related costs are generally allocated based on the number of customers within each
class of service, with appropriate weighting to recognize specific service characteristics.
Allocation FactorDescription-
CUST Customer Count factor is based on the average number of
customers per customer class in the Test Year.
The labor costs associated with planning, gas supply, and control
activities were specifically identified and allocated to the sales and
transportation customer classes based on the time reported by the
personnel in these responsibility centers. First, the expenses were
segregated between sales and transport classes according to the
assigned labor hours and then allocated among the customer
PLAN SUPPLY CTRL classes. A portion of control activities was allocated to customer
classes based on the number of alarms for the specifically
identified customer classes and the remaining costs were allocated
based on the peak demand factor. The planning and supply
related costs were allocated based on the test year weather
normalized volumes. Based on these various components a
composite allocator was created to incorporate this study into
COSS.
INTERMOUNTAIN'S COST OF SERVICE PROCEDURES
Case No. INT-G-25-02
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Exhibit No. 35
Page 6 of 32

Cost of Service Allocation Study
Page 6
Allocation FactorDescription
Meter Allocation factor is based on the weighted customer class
cost of meters used to serve gas customers in different rate
classes. The analysis relies upon the Company's records, which
provide an inventory of each type and size of meter for a specific
customer class, and related meter replacement costs. First, the
MTRS meter records were grouped into rate classes. Next, the average
unit cost per group for each customer class was derived. Then the
relative weighting factor was derived by prorating to Residential
Class unit cost. To derive the allocation basis, the weighted factor
was multiplied by the test year customer bill counts for each
customer class prorated by the groups.
The factor was derived to allocate FERC Account 385 Industrial
measuring and regulating station equipment. The analysis was
M&R performed based on the same set of data used to derive the
Meters allocation factor. Similar steps were taken to develop an
allocation basis but only relying on large meter data and excluding
the Residential and General Service Classes.
The analysis relies upon the data contained in the Company's
property records which provide an inventory and original cost of
the service lines and service lines by diameter. The original cost
data was restated in terms of current cost using Handy-Whitman
indices for services to determine current unit cost. The
interruptible snowmelt customer counts were removed for the
purpose of this analysis, due to their shared service lines with the
customer premise. The records were grouped into three groups:
the Small Service group included service diameters of up to one
SERV and a quarter inch, the next group of Medium Services included
service diameters of two inches, and service lines with over four-
inch diameters were identified as Large Services. Then, the unit
cost per group was derived. Using meter data records, customers
were grouped into similar groups (small meters, medium meters,
and industrial meters). Applying service unit cost to relative
customer group counts determined total estimated service costs
by customer class and service cost per customer. Then the relative
customer class unit cost was developed based on the Residential
Class and multiplied by the test year customer count for each
customer class.
INTERMOUNTAIN'S COST OF SERVICE PROCEDURES
Case No. INT-G-25-02
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Exhibit No. 35
Page 7 of 32

Cost of Service Allocation Study
Page 7
Allocation FactorDescription
ACT 904 The factor is based on the three-year (2022-2024) average of Bad
Debt write-offs.
Demand Allocation Factors
Demand-related costs are generally allocated based on peak capacity demand for each
customer class.
DescriptionAllocation Factor
PDAY F The factor is based on Peak Day capacity demand throughput for
each customer class including Firm customer classes only.
3.3. Mains Analysis
The allocation of investment in facilities serving a distribution function should recognize that
the cost of these facilities is driven by two principal factors. First is the cost of extending the
system to connect individual customers. Second is the cost associated with the capacity
requirements of the customers connected.
There are two widely accepted methods for the classification of mains between customer-
related costs and demand-related costs. The two methods are the Minimum System Method
and the Zero-Intercept Method, both relying on the Company's property record data to
determine the cost of pipe by size and type. Diameter groups that did not contain enough
sample data were removed. The unit cost for pipe in any year is determined by dividing the
booked costs by the amount of pipe installed in a standard unit of measurement. A variety of
factors, such as the length of pipe installed, location, installation conditions, etc., cause the
annual unit cost of pipe by size and type to vary significantly. Thus, a simple average of the
yearly costs is not adequate for a determination of the cost for each size of the pipe as it will
not reflect a consistent set of data. Therefore, the original cost data was restated in terms of
current cost using the Handy-Whitman index.
Zero-Intercept Study:
The zero-intercept study was performed using a Weighted Linear Regression (WLR) on the cost
per foot by pipe diameter. Based on this relationship, the study estimates the cost of installing
a hypothetical pipe with zero capacity, which is where the estimated diameter is zero (i.e., the
zero-intercept). The zero-intercept determined value is then multiplied by all quantities of
distribution mains currently installed by the utility to arrive at a total minimum system cost.
INTERMOUNTAIN'S COST OF SERVICE PROCEDURES
\/ Case No.INT-G-25-02
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Exhibit No. 35
Page 8 of 32

Cost of Service Allocation Study
Page 8
Total minimum system cost divided by total system cost derives the portion of the system that
is considered a fixed investment and is classified as customer-related.
Zero-Intercept
Plastic -Weighted Linear Regression
Steel -Weighted Linear Regression
Material Footage Cost 2024 Zero-Intercept Customer Customer
Plastic 25,877,089 $ 330,641,219 $ 5.94 $ 153,626,945 46%
Steel 9,664,838 $ 858,619,504 $ 56.05 $ 541,694,300 63%
Total 35,541,927 $ 1,189,260,723 $ 695,321,244 58%
The distribution mains investment is functionalized to distribution, classified based on the
results of the zero-intercept study to demand (42%) and customer (58%). The demand
component of the mains investment is allocated based on each class's allocation of peak day.
The customer component of the mains investment is allocated based on each class's number of
customers.
3.4. Internal Allocation Factors
Internal Allocation Factors are developed within the COSS model based on the cost ratios of
allocated cost based the external allocation factors, representing various forms of the
composite external and internal factors as mathematical sums.
Allocation Factor Description The factor is based on the derived rate base by customer class.
INT REV REQ The factor is based on the derived revenue requirement by
customer class.
INT REQ INCOME The factor is based on the derived customer class required return
on the rate base.
INT TOTPLT The factor is based on the total plant in service balance allocated
to the customer classes.
INT STORPT The factor is based on the total Storage plant in service balance
allocated to the customer classes.
INT MISC INTGPLT The factor is based on the Miscellaneous Intangible plant in service
balance allocated to the customer classes.
INT STD PLANT The factor is based on the Storage, Transmission, and Distribution
plant in service balances allocated to the customer classes.
INTERMOUNTAIN'S COST OF SERVICE PROCEDURES
\/ Case No.INT-G-25-02
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Exhibit No. 35
Page 9 of 32

Cost of Service Allocation Study
Page 9
Allocation FactorDescription
The factor is based on the Distribution operation and maintenance
INT_DIST_SUBTOTAL expenses by customer class excluding FERC Accounts 870, 880,
881, 885, and 894.
INT DISTPT The factor is based on the total Distribution plant in service
balance allocated to the customer classes.
INT DMAINS SERV The factor is based on the FERC Accounts 376 - Mains and 380 -
Services balances allocated to the customer classes.
INT MAINS This factor is based on the total Distribution mains plant in service
allocated to the customer classes.
INT GENPLT The factor is based on the General plant in service balance
allocated to the customer classes.
INT TRANSPT The factor is based on the Transmission plant in service balance
allocated to the customer classes.
INT CUSTACC The factor is based on the Customer Account expenses allocated to
the customer classes, excluding FERC Account 901- Supervision.
INT OML The factor is based on the total customer class allocated labor-
- related Operation and Maintenance Expenses.
INT DIST OL The factor is based on the customer class allocated Distribution
labor-related Operation Expenses.
INT DIST ML The factor is based on the customer class allocated Distribution
labor-related Maintenance Expenses.
INT 376-385 This factor is based on the customer class allocated Distribution
plant in service in accounts 376-385.
INTERMOUNTAIN'S COST OF SERVICE PROCEDURES
\/ Case No.INT-G-25-02
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Exhibit No. 35
Page 10 of 32

Cost of Service Allocation Study
Page 10
III. INTERMOUNTAIN'S COST OF SERVICE
RESULTS
Schedule 1 - Account Balances and Allocation Methods
Schedule 2 - External Allocation Factors
Schedule 3 - Internal Allocation Factors
Schedule 4 - Cost of Service and Rate of Return Under Present and Proposed Rates
Schedule S - Cost of Service Allocation Study Detail by Account
Schedule 6 - Functionalized and Classified Rate Base and Revenue Requirement,
and Unit Costs by Customer Class
INTERMOUNTAIN'S COST OF SERVICE RESULTS
\/ Case No.INT-G-25-02
R.Amen,1GC
Exhibit No. 35
Page 11 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 11
Schedule 1-Account Balances and Allocation Methods
Line FERC Internal Functional Classification Demand Commodity Customer
No. Account Description Account Account Balance Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor
1 RATE BASE
2 Plant in Service
3 Intangible Plant
4 Organization 301.0 2,506 INT_STD_PLANT
5 Franchises&Consents 302.0 429,487 INT_STD_PLANT
6 Misc.Intangible Plant-Plant Related 303.0 33,314,052 INT_STD_PLANT
7 Misc.Intangible Plant-Customer Related 303.0 34,682,812 CUSTOMER CUSTOMER CUST
8 Misc.Intangible Plant-Labor Related 303.0 12,238,004 INT_OML
9 Subtotal-Intangible Plant 80,666,861
10 Natural Gas Other Storage Plant
11 Land&Land Rights 360.0 313,452 STORAGE DEMAND PDAY_F
12 Structures&improvement 361.0 12,041,702 STORAGE DEMAND PDAY_F
13 Gas Holders 362.0 11,891,028 STORAGE DEMAND PDAY_F
14 LNG Equipment 363.0 20,484,770 STORAGE DEMAND PDAY_F
15 Subtotal-Natural Gas Other Storage Plant 44,730,952
16 Transmission plant
17 Land and Land Rights 365.1 3,853,192 TRANSMISSION DEMAND PDAY_F
18 Structures and improvements 366.0 77,152 TRANSMISSION DEMAND PDAY_F
19 Mains 367.0 73,366,402 TRANSMISSION DEMAND PDAY_F
20 Compressor station equipment 368.0 32,475,290 TRANSMISSION DEMAND PDAY_F
21 Communication equipment 370.0 714,440 TRANSMISSION DEMAND PDAY_F
22 Subtotal-Transmission plant 110,486,476
23 Distribution Plant
24 Land and land rights 374.0 1,572,737 INT_MAINS
25 Structures and improvements 375.0 326,776 INT_376-385
26 Mains-Demand-related 376.0 149,160,990 DISTRIBUTION DEMAND PDAY_F
27 Mains-Customer-related 377.0 205,984,224 DISTRIBUTION CUSTOMER CUST
28 Measuring and regulating station equipment-general 378.0 16,782,286 INT_MAINS
29 Measuring and regulating station equipment-city gate check stations 379.0 1,834,398 DISTRIBUTION DEMAND PDAY_F
30 Services 380.0 272,146,974 CUSTOMER CUSTOMER SERV
31 Meters 381.0 112,825,353 CUSTOMER CUSTOMER MTRS
32 House regulators 383.0 21,177,214 CUSTOMER CUSTOMER MTRS
33 Industrial measuring and regulating station equipment 385.0 12,831,056 CUSTOMER CUSTOMER M&R
34 Other equipment 387.0 273,973 INT_376-385
35 Subtotal-Distribution Plant 794,915,981
36 General Plant
37 Land and Land Rights 389.0 4,052,523 INT_STD_PLANT
38 Structures and Improvements 390.0 25,051,409 INT_STD_PLANT
39 Office Furniture and Equipment 391.0 6,709,342 INT_OML
40 Transportation Equipment 392.0 16,250,568 INT_STD_PLANT
41 Stores Equipment 393.0 99,370 INT_STD_PLANT
42 Tools,Shop,and Garage Equipment 394.0 11,660,299 INT_STD_PLANT
43 Power Operated Equipment 396.0 4,639,058 INT_STD_PLANT
44 Communication Equipment 397.0 6,886,019 INT_STD_PLANT
45 Misc.Equipment 398.0 88,058 INT_STD_PLANT
46 Subtotal-General Plant 75,436,646
47 Total Plant in Service 1,106,236,916
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 12 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 12
Schedule 1-Account Balances and Allocation Methods
Line FERC Internal Functional Classification Demand Commodity Customer
No. Account Description Account Account Balance Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor
48 Accumulated Depreciation&Amortization
49 Intangible Plant
50 Organization 301.0 (2,506) INT_STD_PLANT - - - - -
51 Franchises&Consents 302.0 (429,487) INT_STD_PLANT - - - -
52 Misc.Intangible Plant-Plant Related 303.0 (45,374,501)INT_MISC_INTGPLT
53 Subtotal-Intangible Plant (45,806,494)
54 Natural Gas Other Storage Plant
55 Land&Land Rights 360.0 - - STORAGE DEMAND PDAY_F - -
56 Structures&improvement 361.0 (4,639,469) - STORAGE DEMAND PDAY_F - -
57 Gas Holders 362.0 (4,891,022) - STORAGE DEMAND PDAY_F - -
58 LNG Equipment 363.0 (10,522,577) - STORAGE DEMAND PDAY_F - -
59 Subtotal-Natural Gas Other Storage Plant (20,053,068)
60 Transmission plant
61 Land and Land Rights 365.1 (505,755) - TRANSMISSION DEMAND PDAY_F - -
62 Structures and improvements 366.0 (69,116) - TRANSMISSION DEMAND PDAY_F - -
63 Mains 367.0 (52,349,257) - TRANSMISSION DEMAND PDAY_F - -
64 Compressor station equipment 368.0 (2,400,940) - TRANSMISSION DEMAND PDAY_F - -
65 Communication equipment 370.0 (751,405) - TRANSMISSION DEMAND PDAY_F - -
66 Subtotal-Transmission plant (56,076,473)
67 Distribution Plant
68 Land and land rights 374.0 (576,921) INT_MAINS - - - - -
69 Structures and improvements 375.0 (33,344) INT_376-385 - - - - -
70 Mains-Demand-related 376.0 (55,157,627) - DISTRIBUTION DEMAND PDAY_F - -
71 Mains-Customer-related 377.0 (76,170,057) - DISTRIBUTION CUSTOMER - - CUST
72 Measuring and regulating station equipment-general 378.0 (4,267,827) INT_MAINS - - - - -
73 Measuring and regulating station equipment-city gate check stations 379.0 (97,508) - DISTRIBUTION DEMAND PDAY_F - -
74 Services 380.0 (134,026,730) - CUSTOMER CUSTOMER - - SERV
75 Meters 381.0 (38,743,449) - CUSTOMER CUSTOMER - - MTRS
76 House regulators 383.0 (7,790,539) - CUSTOMER CUSTOMER - - MTRS
77 Industrial measuring and regulating station equipment 385.0 (8,238,442) - CUSTOMER CUSTOMER - - M&R
78 Other equipment 387.0 (58,318) INT_376-385 - - - - -
79 Subtotal-Distribution Plant (325,160,762)
80 General Plant
81 Land and Land Rights 389.0 - INT_STD_PLANT - - - - -
82 Structures and Improvements 390.0 (10,485,679) INT_STD_PLANT - - - - -
83 Office Furniture and Equipment 391.0 (2,938,414) INT_OML - - - - -
84 Transportation Equipment 392.0 (6,531,348) INT_STD_PLANT - - - - -
85 Stores Equipment 393.0 (16,913) INT_STD_PLANT - - - - -
86 Tools,Shop,and Garage Equipment 394.0 (5,403,760) INT_STD_PLANT - - - - -
87 Power Operated Equipment 396.0 (874,562) INT_STD_PLANT - - - - -
88 Communication Equipment 397.0 (3,533,909) INT_STD_PLANT - - - - -
89 Misc.Equipment 398.0 (87,513) INT_STD_PLANT - - - - -
90 Subtotal-General Plant (29,872,098)
91 Total Accumulated Depreciation&Amortization (476,968,895)
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 13 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 13
Schedule 1-Account Balances and Allocation Methods
Line FERC Internal Functional Classification Demand Commodity Customer
No. Account Description Account Account Balance Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor
92 Other Rate Base Items
93 Materials And Supplies 154.0 (2,195,672)INT_STD_PLANT
94 LNG Inventory 164.2 (4,523,963) STORAGE DEMAND PDAY_F
95 Accumulated deferred income taxes—Storage Plant 282.1 (37,606,342)INT_STORPT
96 Accumulated deferred income taxes—Transmission Plant 282.2 (3,398,748)INT_TRANSPT
97 Accumulated deferred income taxes—Distribution Plant 282.3 7,145,826 INT_DISTPT
98 Accumulated deferred income taxes—General Plant 282.4 3,835,955 INT_GENPLT
99 Customer advances for construction 252.0 (14,051,983)INT DMAINS SERV
100 Total Other Rate Base Items (50,794,927)
101 TOTAL RATE BASE 578,473,094
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 14 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 14
Schedule 1-Account Balances and Allocation Methods
Line FERC Internal Functional Classification Demand Commodity Customer
No. Account Description Account Account Balance Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor
102 OPERATION AND MAINTENANCE EXPENSE
103 Production,Storage,LNG,Transmission,and Distribution Expense
104 Other Gas Supply Expenses
105 Other gas supply expenses 813.0 50,129 DISTRIBUTION DEMAND PDAY_F
106 Other gas supply expenses-Gas Supply 813.1 181,994 DISTRIBUTION DEMAND PLAN_SUPPLY_CTRL
107 Subtotal-Other Gas Supply Expenses 232,123
108 Other Storage Expenses-Operation
109 Operation supervision and engineering 840.0 (400) STORAGE DEMAND PDAY_F
110 Operation labor and expenses 841.0 963,632 STORAGE DEMAND PDAY_F
111 Fuel 842.1 73,240 STORAGE DEMAND PDAY_F
112 Power 842.2 144,240 STORAGE DEMAND PDAY_F
113 Subtotal-Other Storage Expenses-Operation 1,180,712
114 Other Storage Expenses-Maintenance
115 Maintenance of structures and improvements 843.2 3,960 STORAGE DEMAND PDAY_F
116 Maintenance of gas holders 843.3 - STORAGE DEMAND PDAY_F
117 Maintenance of purification equipment 843.4 - STORAGE DEMAND PDAY_F
118 Maintenance of liquefaction equipment 843.5 36,902 STORAGE DEMAND PDAY_F
119 Maintenance of vaporizing equipment 843.6 105,837 STORAGE DEMAND PDAY_F
120 Maintenance of compressor equipment 843.7 33,469 STORAGE DEMAND PDAY_F
121 Maintenance of other equipment 843.9 60,016 STORAGE DEMAND PDAY_F
122 Subtotal-Other Storage Expenses-Maintenance 240,184
123 Transmission Operation Expenses
124 Communication system expenses 852.0 28,148 TRANSMISSION DEMAND PDAY_F
125 Compressor station labor and expenses 853.0 213,607 TRANSMISSION DEMAND PDAY_F
126 Mainsexpenses 856.0 2,883 TRANSMISSION DEMAND PDAY_F
127 Subtotal-Transmission Operation Expenses 244,638
128 Transmission Maintenance Expenses
129 Maintenance of mains 863.0 2,042 TRANSMISSION DEMAND PDAY_F
130 Transmission Mains-Pipeline Integrity 863.1 171,521 TRANSMISSION DEMAND PDAY_F
131 Maintenance of communication equipment 866.0 13,022 TRANSMISSION DEMAND PDAY_F
132 Subtotal-Transmission Maintenance Expenses 186,585
133 Distribution Operation Expenses
134 Operation supervision and engineering 870.0 5,338,801 INT_DIST_OL
135 Operation supervision and engineering-Gas Supply and Control 870.1 76,517 DISTRIBUTION DEMAND PLAN_SUPPLY_CTRL
136 Distribution load dispatching 871.0 326,240 DISTRIBUTION DEMAND PLAN_SUPPLY_CTRL
137 Mains and services expenses 874.0 4,998,638 INT_DMAINS_SERV
138 Mains and services expenses(locating) 874.0 502,765 INT_DMAINS_SERV
139 Mains and services expenses(leak survey) 874.0 217,691 INT_DMAINS_SERV
140 Measuring and regulating station expenses-general 875.0 400,548 INT_MAINS
141 Measuring and regulating station expenses-industrial 876.0 330,947 DISTRIBUTION CUSTOMER M&R
142 Measuring and regulating station expenses-city gate check stations 877.0 184,820 DISTRIBUTION DEMAND PDAY_F
143 Meter and house regulator expenses 878.0 3,569,799 CUSTOMER CUSTOMER MTRS
144 Meter and house regulator expenses-installation credits 878.3 (2,681,987) CUSTOMER CUSTOMER MTRS
145 Customer installations expenses 879.0 810,259 CUSTOMER CUSTOMER CUST
146 Other expenses 880.0 4,154,976 INT_DISTPT
147 Rents 881.0 285,879 INT_DIST_OL
148 Subtotal-Distribution Operation Expenses 18,515,893
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 15 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 15
Schedule 1-Account Balances and Allocation Methods
Line FERC Internal Functional Classification Demand Commodity Customer
No. Account Description Account Account Balance Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor
149 Distribution Maintenance Expenses
150 Maintenance supervision and engineering 885.0 221,166 INT_DIST_ML
151 Maintenance of mains 887.0 1,408,913 INT_MAINS
152 Pipeline Integrity 887.1 20,146 INT_MAINS
153 Maintenance of measuring and regulating station equipment-general 889.0 681,976 INT_MAINS
154 Maintenance of measuring and regulating station equipment-industrial 890.0 165,055 CUSTOMER CUSTOMER M&R
155 Maintenance of measuring and regulating station equipment-City Gate 891.0 55,603 DISTRIBUTION DEMAND PDAY_F
156 Maintenance of services 892.0 2,724,977 DISTRIBUTION CUSTOMER SERV
157 Maintenance of meters and house regulators 893.0 1,880,450 DISTRIBUTION CUSTOMER MTRS
158 Maintenance of Other Equipment 894.0 1,319,475 INT_DIST_ML
159 Subtotal-Distribution Maintenance Expenses 8,477,761
160 Total Production,Storage,LNG,Transmission,and Distribution Expense 29,077,896
161 Customer Accounts,Service,and Sales Expense
162 Customer Account
163EUncollectible
ion 901.0 238,082 INT_CUSTACC
164eading expenses 902.0 1,011,548 CUSTOMER CUSTOMER CUST
165er records and collection expenses 903.0 8,526,279 CUSTOMER CUSTOMER CUST
166 accounts 904.0 1,017,994 CUSTOMER CUSTOMER ACT_904
167 Subtotal-Customer Account 10,793,803
168 Customer Service&Information Expenses
169 Supervision 907.0 -
170 Customer assistance expenses 908.0 64,909 CUSTOMER CUSTOMER CUST
171 Informational and instructional advertising expenses 909.0 134,307 CUSTOMER CUSTOMER CUST
172 Subtotal-Customer Service&Information Expenses 199,216
173 Sales Expenses
174 Supervision 910.0 368,525 CUSTOMER CUSTOMER CUST
175 Demonstrating and selling expenses 912.0 1,426,550 CUSTOMER CUSTOMER CUST
176 Advertising expenses 913.0 39,857 CUSTOMER CUSTOMER CUST
177 Subtotal-Sales Expenses 1,834,932
178 Total Customer Accounts,Service,and Sales Expense 12,827,951
179 Administrative and General Expenses
180 Administrative and general salaries 920.0 8,169,928 INT_OML
181 Administrative and general salaries-Gas Supply and Control 920.1 126,823 CUSTOMER CUSTOMER PLAN_SUPPLY_CTRL
182 Office supplies and expenses 921.0 6,992,401 INT_OML
183 Outside services employed 923.0 711,958 INT_OML
184 Property insurance 924.0 255,881 INT_TOTPLT
185 Injuries and damages 925.0 2,055,873 INT_OML
186 Employee pensions and benefits 926.0 1,690,883 INT_OML
187 Franchise requirements 927.0 -
188 Regulatory commission expenses 928.0 192,974 CUSTOMER CUSTOMER REV
189 General advertising expenses 930.1 71,220 CUSTOMER CUSTOMER CUST
190 Miscellaneous general expenses 930.2 254,999 INT_DIST_SUBTOTAL
191 Miscellaneous general expenses 930.7 353,491 INT_DIST_SUBTOTAL
192 Rents 931.0 1,021,585 INT_OML
193 Maintenance of general plant 932.0 -
194 Maintenance of general plant 935.0 204 INT_GENPLT
195 Total Administrative and General Expenses 21,898,220
196 TOTAL OPERATION AND MAINTENANCE EXPENSE 63,804,067 Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 16 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 16
Schedule 1-Account Balances and Allocation Methods
Line FERC Internal Functional Classification Demand Commodity Customer
No. Account Description Account Account Balance Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor
197 Adjustments,Depreciation and Amortization Expense
198 Depreciation Expense
199 Intangible Plant
200 Organization 301.0 - INT_STD_PLANT - - - -
201 Franchises&Consents 302.0 - INT_STD_PLANT - - - -
202 Misc.Intangible Plant-Plant Related 303.0 6,882,197 INT_MISC_INTGPLT - - - -
203 Subtotal-Intangible Plant 6,882,197
204 Natural Gas Other Storage Plant
205 Land&Land Rights 360.0 - - STORAGE DEMAND PDAY_F - -
206 Structures&improvement 361.0 474,780 - STORAGE DEMAND PDAY_F - -
207 Gas Holders 362.0 345,107 - STORAGE DEMAND PDAY_F - -
208 LNG Equipment 363.0 410,012 - STORAGE DEMAND PDAY_F - -
209 Subtotal-Natural Gas Other Storage Plant 1,229,899
210 Transmission plant
211 Land and Land Rights 365.1 13,387 - TRANSMISSION DEMAND PDAY_F - -
212 Structures and improvements 366.0 2,832 - TRANSMISSION DEMAND PDAY_F - -
213 Mains 367.0 968,436 - TRANSMISSION DEMAND PDAY_F - -
214 Compressor station equipment 368.0 1,909,547 - TRANSMISSION DEMAND PDAY_F - -
215 Communication equipment 370.0 - - TRANSMISSION DEMAND PDAY_F - -
216 Subtotal-Transmission plant 2,894,202
217 Distribution Plant
218 Land and land rights 374.0 23,479 INT_MAINS - - - - -
219 Structures and improvements 375.0 9,182 INT_376-385 - - - - -
220 Mains-Demand-related 376.0 2,409,049 - DISTRIBUTION DEMAND PDAY_F - -
221 Mains-Customer-related 377.0 3,326,783 - DISTRIBUTION CUSTOMER - - CUST
222 Measuring and regulating station equipment-general 378.0 471,582 INT_MAINS - - - - -
223 Measuring and regulating station equipment-city gate check stations 379.0 54,849 - DISTRIBUTION DEMAND PDAY_F - -
224 Services 380.0 7,355,118 - CUSTOMER CUSTOMER - - SERV
225 Meters 381.0 3,177,066 - CUSTOMER CUSTOMER - - MTRS
226 House regulators 383.0 349,425 - CUSTOMER CUSTOMER - - MTRS
227 Industrial measuring and regulating station equipment 385.0 243,790 - CUSTOMER CUSTOMER - - M&R
228 Other equipment 387.0 5,205 INT_376-385 - - - - -
229 Subtotal-Distribution Plant 17,425,528
230 General Plant
231 Land and Land Rights 389.0 - INT_STD_PLANT - - - - -
232 Structures and Improvements 390.0 340,698 INT_STD_PLANT - - - - -
233 Office Furniture and Equipment 391.0 395,180 INT_OML - - - - -
234 Transportation Equipment 392.0 13,416 INT_STD_PLANT - - - - -
235 Stores Equipment 393.0 2,921 INT_STD_PLANT - - - - -
236 Tools,Shop,and Garage Equipment 394.0 831,380 INT_STD_PLANT - - - - -
237 Power Operated Equipment 396.0 - INT_STD_PLANT - - - - -
238 Communication Equipment 397.0 724,597 INT_STD_PLANT - - - - -
239 Misc.Equipment 398.0 2,177 INT_STD_PLANT - - - - -
240 Subtotal-General Plant 2,310,369
241 Total-Depreciation Expense 30,742,195
242 Total Adjustments,Depreciation and Amortization Expense 30,742,195
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 17 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 17
Schedule 1-Account Balances and Allocation Methods
Line FERC Internal Functional Classification Demand Commodity Customer
No. Account Description Account Account Balance Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor Allocation Factor
243 Taxes
244 Taxes Other Than Income Taxes
245 Taxes Other ThanlncomeTaxes-Payroll 408.1 2,437,202 INT_OML
246 Taxes Other Than Income Taxes-Property 408.1 - INT_TOTPLT
247 Taxes Other ThanlncomeTaxes-Franchise 408.1 25,207 CUSTOMER CUSTOMER REV
248 Taxes Other Than Income Taxes-IPUC Fee 408.1 886,919 CUSTOMER CUSTOMER REV
249 Subtotal-Taxes Other ThanlncomeTaxes 3,349,328
250 Income Taxes
251 IncomeTaxes-Federal 409.1 1,488,471 INT REC_INCOME
252 Income Taxes-State 409.1 (211,845)INT_REQ_INCOME
253 Income Taxes-Other 410.1 -
254 Subtotal-Income Taxes 1,276,626
255 Total Taxes 4,625,954
256 REVENUE REQUIREMENT AT EQUAL RATES OF RETURN
257 Test Year Expenses at Current Rates 99,172,216
258 Return on Rate Base 45,467,985 INT_RATEBASE
259 Gross Up Items
260 Gross-up Federal Income Tax 5,243,171 INT_REQ_INCOME
261 Gross-up State Utility Tax 1,397,347 INT_RECI_INCOME
262 Gross-up Bad Debts 75,550 CUSTOMER CUSTOMER ACT_904
263 Gross-up Annual Filing Fee 58,908 CUSTOMER CUSTOMER REV
264 TOTAL REVENUE REQUIREMENT AT EQUAL RATES OF RETURN 151,415,177
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 18 of 32

Intermountain Natural Gas Company
Gas Class Cost of Service Study Page 18
Test Year Ended December 31,2024
Schedule 2-External Allocation Factors
Residential Transport Service Transport Service
Line Allocator Code Description Total Service General Service Large Volume (Interruptible) (Firm)
RS GS LV-1 T-3 T-4
1 CUSTOMER EXTERNAL ALLOCATORS
2 CUST Average Number Customers 100.0% 91.5% 8.4% 0.0% 0.0% 0.0%
3 440,266 402,961 37,153 38 9 105
4 PLAN_SUPPLY_CTRL Gas Supply and Control Cost Allocation 100.0% 36.8% 15.9% 2.5% 1.4% 43.4%
5 711,575 261,654 113,095 18,109 10,229 308,487
6 MTRS Customer Meters 100.0% 74.0% 24.0% 0.4% 0.1% 1.4%
7 Test Year Replacement Cost 87,725,231 64,917,796 21,061,562 382,326 105,929 1,257,618
8 M&R Industrial measuring and regulating station equipment 100.0% 0.0% 0.0% 17.2% 7.0% 75.8%
9 Large Meter Replacement Cost 1,423,277 244,193 99,745 1,079,339
10 SERV Services 100.0% 87.7% 11.5% 0.3% 0.0% 0.5%
11 Weighted Customer Cost 459,278 402,618 52,825 1,195 137 2,503
12 ACT_904 Uncollectible accounts 100.0% 87.0% 13.0% 0.0% 0.0% 0.0%
13 Uncollectible accounts 3 Yr Average $ 1,001,999 $ 872,193 $ 129,806 $ $ - $ -
14 COMMODITY EXTERNAL ALLOCATORS
15 REV Total Sales and Transportation 100.0% 66.7% 23.6% 0.6% 0.5% 8.5%
16 1 $119,595,3281 $79,817,6791 $28,264,2611 $777,0241 $563,9131 $10,172,451
17 COM Weather Normalized Volumes 100.0% 36.1% 17.3% 1.8% 4.5% 40.3%
18 857,517,633 309,250,607 148,742,341 15,440,184 38,382,448 345,702,053
19 DEMAND EXTERNAL ALLOCATORS
20 PDAY F Peak Day(Design Day)Firm 100.0% 53.7% 22.3% 1.2% 0.0% 22.8%
21 6,698,285 3,598,775 1,490,975 82,005 1,526,530
23 FUNCTIONAL PLANT ALLOCATORS
24 Intangible Plant(FERC Account 303)
25 Miscellaneous Intangible Plant -Plant Related 41.5%
26 Miscellaneous Intangible Plant -Customer Related 43.2%
27 Miscellaneous Intangible Plant -Labor Related 15.3%
28 MAINS CLASSIFICATION
29 Customer and Demand Componenets of Mains
30 Demand Component 42%
Case No.INT-G-25-02
31 Zero-Intercept Customer Component 58%
R.Amen,IGC
Exhibit No. 35
Page 19 of 32

Intermountain Gas Company
Gas Class Cost of Service Study Page 19
Test Year Ended December 31,2024
Schedule 3-Internal Allocations
Line Residential Transport Service Transport Service
No. Category Description Total System Service General Service Large Volume (Interruptible) (Firm)
1 Allocation Basis
2 INT_MISC_INTGPLT 80,234,868 65,665,269 10,247,048 367,840 71,771 3,882,940
3 INT_STORPT 44,730,952 24,032,515 9,956,688 547,627 - 10,194,122
4 INT_TRANSPT 110,486,476 59,360,862 24,593,247 1,352,651 - 25,179,716
5 INT_DISTPT 794,915,981 621,747,695 117,169,610 5,459,062 1,147,758 49,391,856
6 INT_376-385 792,742,495 620,087,999 116,857,044 5,446,769 1,146,870 49,203,813
7 INT_GENPLT 75,436,646 56,048,219 12,071,320 590,891 99,919 6,626,297
8 INT_TOTPLT 1,106,236,916 827,175,164 174,106,894 8,321,417 1,319,969 95,313,472
9 INT_RATEBASE 578,473,094 442,538,480 89,845,602 3,717,614 574,349 41,797,050
10 INT_DMAINS_SERV 627,292,188 507,242,899 81,886,286 2,551,730 85,643 35,525,630
11 INT_MAINS 355,145,214 268,669,894 50,584,490 1,843,910 4,211 34,042,710
12 INT_OML 22,511,571 16,918,157 3,679,987 196,475 56,691 1,660,262
13 INT_DIST_01- 10,654,262 7,982,058 1,743,850 100,865 31,650 795,840
14 INT_DIST_ML 4,967,888 3,941,221 775,415 30,329 7,071 213,853
15 INT_CUSTACC 10,555,721 9,615,682 936,746 823 195 2,275
16 INT_LABOR 31,800,101 25,418,616 4,464,859 197,275 56,881 1,662,472
17 INT_REV_REQ 151,415,177 116,625,079 22,889,275 1,046,932 226,910 10,626,981
18 INT_DIST_SUBTOTAL 15,673,357 11,980,848 2,268,246 153,819 45,535 1,224,909
19 INT_STD_PLANT 950,133,409 705,141,072 151,719,544 7,359,340 1,147,758 84,765,695
20 INT_RECI-INCOME 45,467,985 34,783,524 7,061,864 292,204 45,144 3,285,248
21 Allocation Percentage
22 INT_MISC_INTGPLT 100.0% 81.8% 12.8% 0.5% 0.1% 4.8%
23 INT_STORPT 100.0% 53.7% 22.3% 1.2% 0.0% 22.8%
24 INT_TRANSPT 100.0% 53.7% 22.3% 1.2% 0.0% 22.8%
25 INT_DISTPT 100.0% 78.2% 14.7% 0.7% 0.1% 6.2%
26 INT_376-385 100.0% 78.2% 14.7% 0.7% 0.1% 6.2%
27 INT_GENPLT 100.0% 74.3% 16.0% 0.8% 0.1% 8.8%
28 INT_TOTPLT 100.0% 74.8% 15.7% 0.8% 0.1% 8.6%
29 INT_RATEBASE 100.0% 76.5% 15.5% 0.6% 0.1% 7.2%
30 INT_DMAINS_SERV 100.0% 80.9% 13.1% 0.4% 0.0% 5.7%
31 INT_MAINS 100.0% 75.7% 14.2% 0.5% 0.0% 9.6%
32 INT_OML 100.0% 75.2% 16.3% 0.9% 0.3% 7.4%
33 INT_DIST_OL 100.0% 74.9% 16.4% 0.9% 0.3% 7.5%
34 INT_DIST_ML 100.0% 79.3% 15.6% 0.6% 0.1% 4.3%
35 INT_CUSTACC 100.0% 91.1% 8.9% 0.0% 0.0% 0.0%
36 INT_LABOR 100.0% 79.9% 14.0% 0.6% 0.2% 5.2%
37 INT_REV_REQ 100.0% 77.0% 15.1% 0.7% 0.1% 7.0%
38 INT_DIST_SUBTOTAL 100.0% 76.4% 14.5% 1.0% 0.3% 7.8%
39 INT_STD_PLANT 100.0% 74.2% 16.0% 0.8% 0.1% 8.9%
40 INT_REQ_lNCOME 100.0% 76.5% 15.5% 0.6% 0.1% 7.2%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 20 of 32

Intermountain Gas Company
Gas Class Cost of Service Study Page 20
Test Year Ended December 31,2024
Schedule 4-Summary of Cost of Service and Rate of Return Under Present and Proposed Rates
Line Transport Service Transport Service
No. Category Description Total System Residential Service General Service Large Volume (Interruptible) (Firm)
1 Rate Base
2 Plant in Service $ 1,106,236,916 $ 827,175,164 $ 174,106,894 $ 8,321,417 $ 1,319,969 $ 95,313,472
3 Accumulated Reserve (476,968,895) (355,622,299) (73,609,121) (4,051,358) (756,448) (42,929,669)
4 Other Rate Base Items (50,794,927) (29,014,385) (10,652,171) (552,445) 10,828 (10,586,754)
5 Total Rate Base $ 578,473,094 $ 442,538,480 $ 89,845,602 $ 3,717,614 $ 574,349 $ 41,797,050
6 Rate of Return Under Current ROR
7 Revenue at Current Rates
8 Gas Service Revenue $ 119,595,328 $ 79,817,679 $ 28,264,261 $ 777,024 $ 563,913 $ 10,172,451
9 Other Revenues 5,320,360 4,097,921 804,273 36,787 7,973 373,406
10 Total Revenue at Current Rates $ 124,915,688 $ 83,915,600 $ 29,068,534 $ 813,811 $ 571,886 $ 10,545,857
11 Operating Expenses at Current Rates
12 O&M and A&G Expenses $ 63,804,067 $ 49,860,987 $ 9,198,271 $ 466,495 $ 130,086 $ 4,148,229
13 Depreciation and Amortization Expense 30,742,195 23,378,400 4,761,802 209,772 33,104 2,359,117
14 Taxes Other Than Income 3,349,328 2,440,385 613,977 27,197 10,438 257,330
15 Total Operating Expenses at Current Rates $ 97,895,590 $ 75,679,772 $ 14,574,049 $ 703,464 $ 173,628 $ 6,764,676
16 Earnings Before Interest and Taxes $ 27,020,098 $ 8,235,828 $ 14,494,485 $ 110,346 $ 398,258 $ 3,781,181
17 Current State/Federal Income Taxes $ 1,276,626 $ 389,120 $ 684,825 $ 5,214 $ 18,817 $ 178,650
18 Deferred Income Tax - - - - - -
19 Total Income Taxes $ 1,276,626 $ 389,120 $ 684,825 $ 5,214 $ 18,817 $ 178,650
20 Total Expenses at Current Rates $ 99,172,216 $ 76,068,893 $ 15,258,874 $ 708,678 $ 192,445 $ 6,943,327
21 Operating Income at Current Rates $ 25,743,472 $ 7,846,707 $ 13,809,660 $ 105,133 $ 379,442 $ 3,602,530
22 Current Rate of Return 4.45% 1.77% 15.37% 2.83% 66.06% 8.62%
23 Relative Rate of Return 1.00 0.40 3.45 0.64 14.85 1.94
24 Current Revenue to Cost Ratio 0.82 0.72 1.27 0.78 2.52 0.99
25 Current Parity Ratio 1.00 0.87 1.54 0.94 3.05 1.20
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 35
Page 21 of 32

Intermountain Gas Company
Gas Class Cost of Service Study Page 21
Test Year Ended December 31,2024
Schedule 4-Summary of Cost of Service and Rate of Return Under Present and Proposed Rates
Line Transport Service Transport Service
No. Category Description Total System Residential Service General Service Large Volume (Interruptible) (Firm)
26 Rate of Return Under Equal ROR
27 Revenue Requirement at Equal Rates of Return
28 Required Return 7.86% 7.86% 7.86% 7.86% 7.86% 7.86%
29 Required Operating Income $ 45,467,985 $ 34,783,524 $ 7,061,864 $ 292,204 $ 45,144 $ 3,285,248
30 Expenses at Required Return
31 O&M and A&G Expenses 63,804,067 49,860,987 9,198,271 466,495 130,086 4,148,229
32 Depreciation and Amortization Expense 30,742,195 23,378,400 4,761,802 209,772 33,104 2,359,117
33 Taxes Other Than Income 3,349,328 2,440,385 613,977 27,197 10,438 257,330
34 Total Operating Expenses at Required Return $ 97,895,590 $ 75,679,772 $ 14,574,049 $ 703,464 $ 173,628 $ 6,764,676
35 Current State/Federal Income Taxes $ 1,276,626 $ 976,633 $ 198,279 $ 8,204 $ 1,268 $ 92,241
36 Deferred Income Tax $ $ - $ - $ - $ - $ -
37 Income Taxes and Other $ 1,276,626 $ 976,633 $ 198,279 $ 8,204 $ 1,268 $ 92,241
38 Increase-Federal Income Tax 5,243,171 4,011,085 814,344 33,696 5,206 378,841
39 Increase-State Utility Tax 1,397,347 1,068,986 217,029 8,980 1,387 100,964
40 Increase-Bad Debts 75,550 65,763 9,787 - - -
41 Increase-Annual Filing Fee 58,908 39,315 13,922 383 278 5,011
42 Revenue Increase Related Expenses $ 6,774,976 $ 5,185,149 $ 1,055,082 $ 43,059 $ 6,871 $ 484,815
43 Total Expenses at Required Return $ 105,947,192 $ 81,841,555 $ 15,827,410 $ 754,727 $ 181,766 $ 7,341,733
44 Total Revenue Requirement at Equal Rates of Return $ 151,415,177 $ 116,625,079 $ 22,889,275 $ 1,046,932 $ 226,910 $ 10,626,981
45 LESS
46 Current Miscellaneous Revenue Margin 5,320,360 4,097,921 804,273 36,787 7,973 373,406
47 Total Rate Margin at Equal Rates of Return $ 146,094,817 $ 112,527,159 $ 22,085,001 $ 1,010,145 $ 218,937 $ 10,253,575
48 Total Current Rate Margin $ 119,595,328 $ 79,817,679 $ 28,264,261 $ 777,024 $ 563,913 $ 10,172,451
49 Base Rate Margin(Deficiency)/Surplus $ (26,499,489) $ (32,709,480) $ 6,179,260 $ (233,121) $ 344,976 $ (81,124)
50 Proposed Margin Increase $ 26,499,489 $ 21,222,846 $ 3,705,260 $ 206,604 $ 31,237 $ 1,333,542
51 Total Revenue Increase as Proposed $ 151,415,177 $ 105,138,446 $ 32,773,794 $ 1,020,415 $ 603,124 $ 11,879,399
52 Income Prior to Taxes $ 53,385,129 $ 29,353,596 $ 18,176,036 $ 316,568 $ 429,218 $ 5,109,712
53 Income Taxes $ 7,917,144 $ 6,056,705 $ 1,229,652 $ 50,880 $ 7,861 $ 572,046
54 Proposed Operating Income $ 45,467,985 $ 23,296,891 $ 16,946,384 $ 265,687 $ 421,357 $ 4,537,666
55 Proposed Rate of Return 7.86% 5.26% 18.86% 7.15% 73.36% 10.86%
56 Relative Rate of Return 1.00 0.67 2.40 0.91 9.33 1.38
57 Proposed Revenue to Cost Ratio 1.00 0.90 1.43 0.97 2.66 1.12
58 Proposed Parity Ratio 1.00 0.90 1.43 0.97 2.66 case No.INT1ki-25-02
R.Amen,IGC
Exhibit No. 35
Page 22 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 22
Schedule 5-Cost of Service Allocation Study Detail by Account
Line FERC Residential Transport Service Transport Service
No. Account Description Account Account Balance Service General Service Large Volume (Interruptible) (Firm)
1 RATE BASE
2 Plant in Service
3 Intangible Plant
4 Organization 301 2,506 1,860 400 19 3 224
5 Franchises&Consents 302 429,487 318,744 68,581 3,327 519 38,316
6 Misc.Intangible Plant-Plant Related 303 33,314,052 24,724,008 5,319,666 258,037 40,243 2,972,097
7 Misc.Intangible Plant-Customer Related 303 34,682,812 31,744,014 2,926,824 2,994 709 8,272
8 Misc.Intangible Plant-Labor Related 303 12,238,004 9,197,247 2,000,558 106,810 30,819 902,571
9 Subtotal-Intangible Plant 80,666,861 65,985,872 10,316,030 371,186 72,293 3,921,480
10 Natural Gas Other Storage Plant
11 Land&Land Rights 360 313,452 168,408 69,771 3,837 - 71,435
12 Structures&improvement 361 12,041,702 6,469,623 2,680,369 147,423 - 2,744,287
13 Gas Holders 362 11,891,028 6,388,670 2,646,831 145,578 - 2,709,949
14 LNG Equipment 363 20,484,770 11,005,814 4,559,716 250,789 - 4,668,451
15 Subtotal-Natural Gas Other Storage Plant 44,730,952 24,032,515 9,956,688 547,627 - 10,194,122
16 Transmission plant
17 Land and Land Rights 365.1 3,853,192 2,070,197 857,684 47,173 - 878,137
18 Structures and improvements 366 77,152 41,451 17,173 945 - 17,583
19 Mains 367 73,366,402 39,417,430 16,330,669 898,202 - 16,720,102
20 Compressor station equipment 368 32,475,290 17,447,938 7,228,693 397,585 - 7,401,074
21 Communication equipment 370 714,440 383,846 159,028 8,747 - 162,820
22 Subtotal-Transmission plant 110,486,476 59,360,862 24,593,247 1,352,651 - 25,179,716
23 Distribution Plant
24 Land and land rights 374 1,572,737 1,189,787 224,010 8,166 19 150,756
25 Structures and improvements 375 326,776 255,606 48,170 2,245 473 20,282
26 Mains-Demand-related 376 149,160,990 80,139,446 33,201,828 1,826,131 - 33,993,585
27 Mains-Customer-related 377 205,984,224 188,530,448 17,382,661 17,779 4,211 49,126
28 Measuring and regulating station equipment-general 378 16,782,286 12,695,919 2,390,356 87,133 199 1,608,679
29 Measuring and regulating station equipment-city gate check stations 379 1,834,398 985,564 408,320 22,458 - 418,057
30 Services 380 272,146,974 238,573,005 31,301,796 707,820 81,432 1,482,920
31 Meters 381 112,825,353 83,492,207 27,087,739 491,718 136,238 1,617,451
32 House regulators 383 21,177,214 15,671,410 5,084,344 92,295 25,572 303,594
33 Industrial measuring and regulating station equipment 385 12,831,056 - - 2,201,434 899,218 9,730,403
34 Other equipment 387 273,973 214,303 40,386 1,882 396 17,005
35 Subtotal-Distribution Plant 794,915,981 621,747,695 117,169,610 5,459,062 1,147,758 49,391,856
36 General Plant
37 Land and Land Rights 389 4,052,523 3,007,578 647,116 31,389 4,895 361,544
38 Structures and Improvements 390 25,051,409 18,591,892 4,000,268 194,038 30,262 2,234,949
39 Office Furniture and Equipment 391 6,709,342 5,042,282 1,096,782 58,557 16,896 494,824
40 Transportation Equipment 392 16,250,568 12,060,352 2,594,929 125,870 19,631 1,449,797
41 Stores Equipment 393 99,370 73,747 15,868 770 120 8,865
42 Tools,Shop,and Garage Equipment 394 11,660,299 8,653,686 1,861,944 90,316 14,086 1,040,268
43 Power Operated Equipment 396 4,639,058 3,442,875 740,776 35,932 5,604 413,871
44 Communication Equipment 397 6,886,019 5,110,456 1,099,576 53,336 8,318 614,333
45 Misc.Equipment 398 88,058 65,352 14,061 682 106 7,856
46 Subtotal-General Plant 75,436,646 56,048,219 12,071,320 590,891 99,919 6,626,297
47 Total Plant in Service 1,106,236,916 827,175,164 174,106,894 8,321,417 1,319,969 95,313,472
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 23 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 23
Schedule 5-Cost of Service Allocation Study Detail by Account
Line FERC Residential Transport Service Transport Service
No. Account Description Account Account Balance Service General Service Large Volume (Interruptible) (Firm)
48 Accumulated Depreciation&Amortization
49 Intangible Plant
50 Organization 301 (2,506) (1,860) (400) (19) (3) (224)
51 Franchises&Consents 302 (429,487) (318,744) (68,581) (3,327) (519) (38,316)
52 Misc.Intangible Plant-Plant Related 303 (45,374,501) (37,135,087) (5,794,921) (208,021) (40,588) (2,195,894)
53 Subtotal-Intangible Plant (45,806,494) (37,455,690) (5,863,902) (211,367) (41,110) (2,234,424)
54 Natural Gas Other Storage Plant
55 Land&Land Rights 360 - - - - - -
56 Structures&improvement 361 (4,639,469) (2,492,639) (1,032,702) (56,800) - (1,057,329)
57 Gas Holders 362 (4,891,022) (2,627,790) (1,088,695) (59,879) - (1,114,657)
58 LNG Equipment 363 (10,522,577) (5,653,445) (2,342,226) (128,825) - (2,398,081)
59 Subtotal-Natural Gas Other Storage Plant (20,053,068) (10,773,874) (4,463,624) (245,503) - (4,570,067)
60 Transmission plant
61 Land and Land Rights 365.1 (505,755) (271,726) (112,576) (6,192) - (115,261)
62 Structures and improvements 366 (69,116) (37,134) (15,385) (846) - (15,751)
63 Mains 367 (52,349,257) (28,125,587) (11,652,450) (640,895) - (11,930,324)
64 Compressor station equipment 368 (2,400,940) (1,289,949) (534,427) (29,394) - (547,171)
65 Communication equipment 370 (751,405) (403,706) (167,256) (9,199) - (171,244)
66 Subtotal-Transmission plant (56,076,473) (30,128,102) (12,482,094) (686,527) - (12,779,751)
67 Distribution Plant
68 Land and land rights 374 (576,921) (436,445) (82,173) (2,995) (7) (55,301)
69 Structures and improvements 375 (33,344) (26,082) (4,915) (229) (48) (2,070)
70 Mains-Demand-related 376 (55,157,627) (29,634,435) (12,277,567) (675,277) - (12,570,347)
71 Mains-Customer-related 377 (76,170,057) (69,715,897) (6,427,863) (6,574) (1,557) (18,166)
72 Measuring and regulating station equipment-general 378 (4,267,827) (3,228,642) (607,880) (22,159) (51) (409,096)
73 Measuring and regulating station equipment-city gate check stations 379 (97,508) (52,388) (21,704) (1,194) - (22,222)
74 Services 380 (134,026,730) (117,492,248) (15,415,484) (348,587) (40,104) (730,307)
75 Meters 381 (38,743,449) (28,670,649) (9,301,743) (168,853) (46,783) (555,421)
76 House regulators 383 (7,790,539) (5,765,099) (1,870,396) (33,953) (9,407) (111,694)
77 Industrial measuring and regulating station equipment 385 (8,238,442) - - (1,413,476) (577,361) (6,247,605)
78 Other equipment 387 (58,318) (45,617) (8,597) (401) (84) (3,620)
79 Subtotal-Distribution Plant (325,160,762) (255,067,500) (46,018,323) (2,673,697) (675,403) (20,725,839)
80 General Plant
81 Land and Land Rights 389 - - - - - -
82 Structures and Improvements 390 (10,485,679) (7,781,942) (1,674,378) (81,218) (12,667) (935,475)
83 Office Furniture and Equipment 391 (2,938,414) (2,208,311) (480,345) (25,646) (7,400) (216,712)
84 Transportation Equipment 392 (6,531,348) (4,847,237) (1,042,941) (50,589) (7,890) (582,691)
85 Stores Equipment 393 (16,913) (12,552) (2,701) (131) (20) (1,509)
86 Tools,Shop,and Garage Equipment 394 (5,403,760) (4,010,398) (862,885) (41,855) (6,528) (482,094)
87 Power Operated Equipment 396 (874,562) (649,056) (139,652) (6,774) (1,056) (78,024)
88 Communication Equipment 397 (3,533,909) (2,622,689) (564,303) (27,372) (4,269) (315,276)
89 Misc.Equipment 398 (87,513) (64,948) (13,974) (678) (106) (7,807)
90 Subtotal-General Plant (29,872,098) (22,197,132) (4,781,179) (234,263) (39,936) (2,619,588)
91 Total Accumulated Depreciation&Amortization (476,968,895) (355,622,299) (73,609,121) (4,051,358) (756,448) (42,929,669)
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 24 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 24
Schedule 5-Cost of Service Allocation Study Detail by Account
Line FERC Residential Transport Service Transport Service
No. Account Description Account Account Balance Service General Service Large Volume (Interruptible) (Firm)
92 Other Rate Base Items
93 Materials And Supplies 154 (2,195,672) (1,629,517) (350,610) (17,007) (2,652) (195,886)
94 LNG Inventory 164.2 (4,523,963) (2,430,581) (1,006,991) (55,385) - (1,031,005)
95 Accumulated deferred income taxes—Storage Plant 282.1 (37,606,342) (20,204,689) (8,370,817) (460,403) - (8,570,434)
96 Accumulated deferred income taxes—Transmission Plant 282.2 (3,398,748) (1,826,039) (756,529) (41,610) - (774,570)
97 Accumulated deferred income taxes—Distribution Plant 282.3 7,145,826 5,589,145 1,053,286 49,074 10,318 444,004
98 Accumulated deferred income taxes—General Plant 282.4 3,835,955 2,850,053 613,827 30,047 5,081 336,947
99 Customer advances for construction 252 (14,051,983) (11,362,757) (1,834,336) (57,161) (1,918) (795,810)
100 Total Other Rate Base Items (50,794,927) (29,014,385) (10,652,171) (552,445) 10,828 (10,586,754)
101 TOTAL RATE BASE 578,473,094 442,538,480 89,845,602 3,717,614 574,349 41,797,050
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 25 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 25
Schedule 5-Cost of Service Allocation Study Detail by Account
Line FERC Residential Transport Service Transport Service
No. Account Description Account Account Balance Service General Service Large Volume (Interruptible) (Firm)
102 OPERATION AND MAINTENANCE EXPENSE
103 Production,Storage,LNG,Transmission,and Distribution Expense
104 Other Gas Supply Expenses
105 Other gas supply expenses 813 50,129 26,933 11,158 614 - 11,424
106 Other gas supply expenses-Gas Supply 813.1 181,994 66,921 28,926 4,632 2,616 78,899
107 Subtotal-Other Gas Supply Expenses 232,123 93,854 40,084 5,245 2,616 90,324
108 Other Storage Expenses-Operation
109 Operation supervision and engineering 840 (400) (215) (89) (5) - (91)
110 Operation labor and expenses 841 963,632 517,729 214,495 11,797 - 219,610
111 Fuel 842.1 73,240 39,350 16,303 897 - 16,691
112 Power 842.2 144,240 77,496 32,106 1,766 - 32,872
113 Subtotal-Other Storage Expenses-Operation 1,180,712 634,359 262,815 14,455 - 269,083
114 Other Storage Expenses-Maintenance
115 Maintenance of structures and improvements 843.2 3,960 2,128 881 48 - 902
116 Maintenance of gas holders 843.3 - - - - - -
117 Maintenance of purification equipment 843.4 - - - - - -
118 Maintenance of liquefaction equipment 843.5 36,902 19,826 8,214 452 - 8,410
119 Maintenance of vaporizing equipment 843.6 105,837 56,863 23,558 1,296 - 24,120
120 Maintenance of compressor equipment 843.7 33,469 17,982 7,450 410 - 7,628
121 Maintenance of other equipment 843.9 60,016 32,245 13,359 735 - 13,678
122 Subtotal-Other Storage Expenses-Maintenance 240,184 129,043 53,463 2,940 - 54,738
123 Transmission Operation Expenses
124 Communication system expenses 852 28,148 15,123 6,265 345 - 6,415
125 Compressor station labor and expenses 853 213,607 114,764 47,547 2,615 - 48,681
126 Mains expenses 856 2,883 1,549 642 35 - 657
127 Subtotal-Transmission Operation Expenses 244,638 131,436 54,454 2,995 - 55,753
128 Transmission Maintenance Expenses
129 Maintenance of mains 863 2,042 1,097 455 25 - 465
130 Transmission Mains-Pipeline Integrity 863.1 171,521 92,153 38,179 2,100 - 39,089
131 Maintenance of communication equipment 866 13,022 6,996 2,899 159 - 2,968
132 Subtotal-Transmission Maintenance Expenses 186,585 100,246 41,532 2,284 - 42,522
133 Distribution Operation Expenses
134 Operation supervision and engineering 870 5,338,801 3,999,771 873,835 50,543 15,859 398,792
135 Operation supervision and engineering-Gas Supply and Control 870.1 76,517 28,136 12,161 1,947 1,100 33,172
136 Distribution load dispatching 871 326,240 119,962 51,852 8,303 4,690 141,434
137 Mains and services expenses 874 4,998,638 4,042,014 652,519 20,334 682 283,089
138 Mains and services expenses(locating) 874 502,765 406,547 65,631 2,045 69 28,473
139 Mains and services expenses(leak survey) 874 217,691 176,030 28,417 886 30 12,329
140 Measuring and regulating station expenses-general 875 400,548 303,017 57,051 2,080 5 38,395
141 Measuring and regulating station expenses-industrial 876 330,947 - - 56,781 23,193 250,973
142 Measuring and regulating station expenses-city gate check stations 877 184,820 99,298 41,139 2,263 - 42,120
143 Meter and house regulator expenses 878 3,569,799 2,641,697 857,057 15,558 4,311 51,176
144 Meter and house regulator expenses-installation credits 878.3 (2,681,987) (1,984,705) (643,906) (11,689) (3,239) (38,449)
145 Customer installations expenses 879 810,259 741,603 68,376 70 17 193
146 Other expenses 880 4,154,976 3,249,836 612,438 28,534 5,999 258,168
147 Rents 881 285,879 214,177 46,792 2,706 849 21,354
148 Subtotal-Distribution Operation Expenses 18,515,893 14,037,385 2,723,362 180,360 53,565 1,521,221
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 26 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 26
Schedule 5-Cost of Service Allocation Study Detail by Account
Line FERC Residential Transport Service Transport Service
No. Account Description Account Account Balance Service General Service Large Volume (Interruptible) (Firm)
149 Distribution Maintenance Expenses
150 Maintenance supervision and engineering 885 221,166 175,460 34,521 1,350 315 9,521
151 Maintenance of mains 887 1,408,913 1,065,853 200,676 7,315 17 135,052
152 Pipeline Integrity 887.1 20,146 15,241 2,869 105 0 1,931
153 Maintenance of measuring and regulating station equipment-general 889 681,976 515,920 97,136 3,541 8 65,371
154 Maintenance of measuring and regulating station equipment-industrial 890 165,055 - - 28,319 11,567 125,169
155 Maintenance of measuring and regulating station equipment-City Gate 891 55,603 29,874 12,377 681 - 12,672
156 Maintenance of services 892 2,724,977 2,388,805 313,421 7,087 815 14,848
157 Maintenance of meters and house regulators 893 1,880,450 1,391,557 451,469 8,195 2,271 26,958
158 Maintenance of Other Equipment 894 1,319,475 1,046,791 205,951 8,055 1,878 56,800
159 Subtotal-Distribution Maintenance Expenses 8,477,761 6,629,500 1,318,420 64,648 16,871 448,322
160 Total Production,Storage,LNG,Transmission,and Distribution Expense 29,077,896 21,755,823 4,494,130 272,928 73,052 2,481,962
161 Customer Accounts,Service,and Sales Expense
162 Customer Account
163 Supervision 901 238,082 216,880 21,128 19 4 51
164 Meter reading expenses 902 1,011,548 925,836 85,363 87 21 241
165 Customer records and collection expenses 903 8,526,279 7,803,817 719,518 736 174 2,033
166 Uncollectible accounts 904 1,017,894 886,029 131,865 - - -
167 Subtotal-Customer Account 10,793,803 9,832,562 957,874 842 199 2,326
168 Customer Service&Information Expenses
169 Supervision 907 - - - - - -
170 Customer assistance expenses 908 64,909 59,409 5,478 6 1 15
171 Informational and instructional advertising expenses 909 134,307 122,927 11,334 12 3 32
172 Subtotal-Customer Service&Information Expenses 199,216 182,336 16,812 17 4 48
173 Sales Expenses
174 Supervision 910 368,525 337,299 31,099 32 8 88
175 Demonstrating and selling expenses 912 1,426,550 1,305,673 120,384 123 29 340
176 Advertising expenses 913 39,857 36,480 3,363 3 1 10
177 Subtotal-Sales Expenses 1,834,932 1,679,452 154,947 158 38 438
178 Total Customer Accounts,Service,and Sales Expense 12,827,951 11,694,349 1,129,533 1,017 241 2,811
179 Administrative and General Expenses
180 Administrative and general salaries 920 8,169,928 6,139,959 1,335,546 71,305 20,574 602,544
181 Administrative and general salaries-Gas Supply and Control 920.1 126,823 46,634 20,157 3,228 1,823 54,981
182 Office supplies and expenses 921 6,992,401 5,255,010 1,143,054 61,028 17,609 515,700
183 Outside services employed 923 711,958 535,059 116,384 6,214 1,793 52,508
184 Property insurance 924 255,881 191,332 40,272 1,925 305 22,047
185 Injuries and damages 925 2,055,973 1,545,053 336,075 17,943 5,177 151,624
186 Employee pensions and benefits 926 1,690,883 1,270,752 276,410 14,758 4,258 124,705
187 Franchise requirements 927 - - - - - -
188 Regulatory commission expenses 928 192,974 128,790 45,606 1,254 910 16,414
189 General advertising expenses 930.1 71,220 65,185 6,010 6 1 17
190 Miscellaneous general expenses 930.2 254,999 194,923 36,903 2,503 741 19,929
191 Miscellaneous general expenses 930.7 353,491 270,212 51,157 3,469 1,027 27,626
192 Rents 931 1,021,585 767,753 166,999 8,916 2,573 75,343
193 Maintenance of general plant 932 - - - - - -
194 Maintenance of general plant 935 204 152 33 2 0 18
195 Total Administrative and General Expenses 21,898,220 16,410,815 3,574,608 192,549 56,792 1,663,456
196 TOTAL OPERATION AND MAINTENANCE EXPENSE 63,804,067 49,860,987 9,198,271 466,495 130,086 4,148,229 Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 27 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 27
Schedule 5-Cost of Service Allocation Study Detail by Account
Line FERC Residential Transport Service Transport Service
No. Account Description Account Account Balance Service General Service Large Volume (Interruptible) (Firm)
197 Adjustments,Depreciation and Amortization Expense
198 Depreciation Expense
199 Intangible Plant
200 Organization 301 - - - - - -
201 Franchises&Consents 302 - - - - - -
202 Misc.Intangible Plant-Plant Related 303 6,882,197 5,632,480 878,947 31,552 6,156 333,062
203 Subtotal-Intangible Plant 6,882,197 5,632,480 878,947 31,552 6,156 333,062
204 Natural Gas Other Storage Plant
205 Land&Land Rights 360 - - - - - -
206 Structures&improvement 361 474,780 255,084 105,682 5,813 - 108,202
207 Gas Holders 362 345,107 185,415 76,818 4,225 - 78,649
208 LNG Equipment 363 410,012 220,286 91,265 5,020 - 93,441
209 Subtotal-Natural Gas Other Storage Plant 1,229,899 660,786 273,764 15,057 - 280,292
210 Transmission plant
211 Land and Land Rights 365.1 13,387 7,192 2,980 164 - 3,051
212 Structures and improvements 366 2,832 1,522 630 35 - 645
213 Mains 367 968,436 520,310 215,565 11,856 - 220,705
214 Compressor station equipment 368 1,909,547 1,025,939 425,047 23,378 - 435,183
215 Communication equipment 370 - - - - - -
216 Subtotal-Transmission plant 2,894,202 1,554,962 644,222 35,433 - 659,585
217 Distribution Plant
218 Land and land rights 374 23,479 17,762 3,344 122 0 2,251
219 Structures and improvements 375 9,182 7,182 1,354 63 13 570
220 Mains-Demand-related 376 2,409,049 1,294,305 536,232 29,493 - 549,019
221 Mains-Customer-related 377 3,326,783 3,044,892 280,742 287 68 793
222 Measuring and regulating station equipment-general 378 471,582 356,755 67,169 2,448 6 45,204
223 Measuring and regulating station equipment-city gate check stations 379 54,849 29,469 12,209 671 - 12,500
224 Services 380 7,355,118 6,447,739 845,971 19,130 2,201 40,078
225 Meters 381 3,177,066 2,351,070 762,768 13,846 3,836 45,546
226 House regulators 383 349,425 258,579 83,892 1,523 422 5,009
227 Industrial measuring and regulating station equipment 385 243,790 - - 41,827 17,085 184,878
228 Other equipment 387 5,205 4,071 767 36 8 323
229 Subtotal-Distribution Plant 17,425,528 13,811,825 2,594,446 109,447 23,639 886,171
230 General Plant
231 Land and Land Rights 389 - - - - - -
232 Structures and Improvements 390 340,698 252,849 54,403 2,639 412 30,395
233 Office Furniture and Equipment 391 395,180 296,990 64,600 3,449 995 29,145
234 Transportation Equipment 392 13,416 9,957 2,142 104 16 1,197
235 Stores Equipment 393 2,921 2,168 466 23 4 261
236 Tools,Shop,and Garage Equipment 394 831,380 617,008 132,757 6,440 1,004 74,171
237 Power Operated Equipment 396 - - - - - -
238 Communication Equipment 397 724,597 537,759 115,705 5,612 875 64,645
239 Misc.Equipment 398 2,177 1,616 348 17 3 194
240 Subtotal-General Plant 2,310,369 1,718,347 370,422 18,283 3,309 200,008
241 Total-Depreciation Expense 30,742,195 23,378,400 4,761,802 209,772 33,104 2,359,117
242 Total Adjustments,Depreciation and Amortization Expense 30,742,195 23,378,400 4,761,802 209,772 33,104 2,359,117
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 28 of 32

Intermountain Gas Company
Gas Class Cost of Service Study
Test Year Ended December 31,2024 Page 28
Schedule 5-Cost of Service Allocation Study Detail by Account
Line FERC Residential Transport Service Transport Service
No. Account Description Account Account Balance Service General Service Large Volume (Interruptible) (Firm)
243 Taxes
244 Taxes Other Than Income Taxes
245 Taxes Other Than Income Taxes-Payroll 408.1 2,437,202 1,831,634 398,412 21,271 6,138 179,747
246 Taxes Other Than Income Taxes-Property 408.1 - - - - - -
247 Taxes Other Than Income Taxes-Franchise 408.1 25,207 16,823 5,957 164 119 2,144
248 Taxes Other Than Income Taxes-IPUC Fee 408.1 886,919 591,928 209,608 5,762 4,182 75,439
249 Subtotal-Taxes Other Than Income Taxes 3,349,328 2,440,385 613,977 27,197 10,438 257,330
250 Income Taxes
251 IncomeTaxes-Federal 409.1 1,488,471 1,138,697 231,182 9,566 1,478 107,548
252 IncomeTaxes-State 409.1 (211,845) (162,064) (32,903) (1,361) (210) (15,307)
253 IncomeTaxes-Other 410.1 - - - - - -
254 Subtotal-IncomeTaxes 1,276,626 976,633 198,279 8,204 1,268 92,241
255 Total Taxes 4,625,954 3,417,019 812,256 35,402 11,706 349,572
256 REVENUE REQUIREMENT AT EQUAL RATES OF RETURN
257 Test Year Expenses at Current Rates 99,172,216 76,656,406 14,772,328 711,669 174,895 6,856,918
258 Return on Rate Base 45,467,985 34,783,524 7,061,864 292,204 45,144 3,285,248
259 Gross Up Items - - - - -
260 Gross-up Federal Income Tax 5,243,171 4,011,085 814,344 33,696 5,206 378,841
261 Gross-up State Utility Tax 1,397,347 1,068,986 217,029 8,980 1,387 100,964
262 Gross-up Bad Debts 75,550 65,763 9,787 - - -
263 Gross-up Annual Filing Fee 58,908 39,315 13,922 383 278 5,011
264 TOTAL REVENUE REQUIREMENT AT EQUAL RATES OF RETURN 151,415,177 116,625,079 22,889,275 1,046,932 226,910 10,626,981
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 29 of 32

Intermountain Gas Company Page 29
Gas Class Cost of Service Study
Test Year Ended December 31,2024
Schedule 6-Functionalized and Classified Rate Base and Revenue Requirement,and Unit Costs by Customer Class
Transport Service Transport Service
Line Description TOTAL Residential Service General Service Large Volume (Interruptible) (Firm)
1 Functional Rate Base
2 Storage
3 Demand $ (14,498,853) $ (7,789,772) $ (3,227,308) $ (177,505) $ $ (3,304,269)
4 Commodity $ - $ - $ - $ $ $
5 Customer $ - $ - $ - $ $ $
6 Subtotal $ (14,498,853) $ (7,789,772) $ (3,227,308) $ (177,505) $ $ (3,304,269)
7 Transmission
8 Demand $ 57,783,351 $ 31,045,153 $ 12,862,028 $ 707,423 $ $ 13,168,746
9 Commodity $ - $ - $ - $ - $ $ -
10 Customer $ - $ - $ - $ - $ $ -
11 Subtotal $ 57,783,351 $ 31,045,153 $ 12,862,028 $ 707,423 $ $ 13,168,746
12 Distribution
13 Demand $ 110,717,696 $ 59,431,587 $ 24,624,629 $ 1,359,649 $ 4,536 $ 25,297,295
14 Commodity $ - $ - $ - $ - $ - $ -
15 Customer $ 151,924,146 $ 138,741,319 $ 12,962,085 $ 44,009 $ 14,432 $ 162,300
16 Subtotal $ 262,641,841 $ 198,172,907 $ 37,586,714 $ 1,403,658 $ 18,968 $ 25,459,595
17 Customer
18 Demand $ - $ - $ - $ - $ - $ -
19 Commodity $ - $ - $ - $ - $ - $ -
20 Customer $ 272,546,755 $ 221,110,193 $ 42,624,167 $ 1,784,038 $ 555,381 $ 6,472,977
21 Subtotal $ 272,546,755 $ 221,110,193 $ 42,624,167 $ 1,784,038 $ 555,381 $ 6,472,977
37 Total
38 Demand $ 154,002,193 $ 82,686,968 $ 34,259,349 $ 1,889,568 $ 4,536 $ 35,161,772
39 Commodity $ - $ - $ - $ - $ - $ -
40 Customer $ 424,470,901 $ 359,851,512 $ 55,586,253 $ 1,828,046 $ 569,813 $ 6,635,277
41 TOTAL RATE BASE $ 578,473,094 $ 442,538,480 $ 89,845,602 $ 3,717,614 $ 574,349 $ 41,797,050
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 30 of 32

Intermountain Gas Company Page 30
Gas Class Cost of Service Study
Test Year Ended December 31,2024
Schedule 6-Functionalized and Classified Rate Base and Revenue Requirement,and Unit Costs by Customer Class
Transport Service Transport Service
Line Description TOTAL Residential Service General Service Large Volume (Interruptible) (Firm)
42 Functional Revenue Requirement
43 Storage
44 Demand $ 2,182,077 $ 1,172,360 $ 485,710 $ 26,714 $ $ 497,292
45 Commodity $ - $ - $ - $ - $ $ -
46 Customer $ - $ - $ - $ - $ $ -
47 Subtotal $ 2,182,077 $ 1,172,360 $ 485,710 $ 26,714 $ $ 497,292
48 Transmission
49 Demand $ 9,444,029 $ 5,073,976 $ 2,102,152 $ 115,620 $ $ 2,152,281
50 Commodity $ - $ - $ - $ - $ $ -
51 Customer $ - $ - $ - $ - $ $ -
52 Subtotal $ 9,444,029 $ 5,073,976 $ 2,102,152 $ 115,620 $ $ 2,152,281
53 Distribution
54 Demand $ 23,011,066 $ 12,081,143 $ 5,016,191 $ 303,679 $ 23,905 $ 5,586,147
55 Commodity $ - $ - $ - $ - $ - $ -
56 Customer $ 40,552,903 $ 35,297,305 $ 4,241,900 $ 186,631 $ 68,207 $ 758,860
57 Subtotal $ 63,563,969 $ 47,378,448 $ 9,258,092 $ 490,310 $ 92,112 $ 6,345,007
58 Customer
59 Demand $ - $ - $ - $ - $ - $ -
60 Commodity $ - $ - $ - $ - $ - $ -
61 Customer $ 76,225,102 $ 63,000,295 $ 11,043,322 $ 414,287 $ 134,798 $ 1,632,401
62 Subtotal $ 76,225,102 $ 63,000,295 $ 11,043,322 $ 414,287 $ 134,798 $ 1,632,401
78 Total
79 Demand $ 34,637,172 $ 18,327,479 $ 7,604,053 $ 446,014 $ 23,905 $ 8,235,720
80 Commodity $ - $ - $ - $ - $ - $ -
81 Customer $ 116,778,005 $ 98,297,600 $ 15,285,222 $ 600,918 $ 203,005 $ 2,391,261
82 TOTAL REVENUE REQUIREMENT AT $ 151,415,177 $ 116,625,079 $ 22,889,275 $ 1,046,932 $ 226,910 $ 10,626,981
EQUAL RATES OF RETURN
83 Demand 22.88% 15.71% 33.22% 42.60% 10.54% 77.50%
84 Energy 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%
85 Customer 77.12% 84.29% 66.78% 57.40% 89.46% 22.50%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 31 of 32

Intermountain Gas Company Page 31
Gas Class Cost of Service Study
Test Year Ended December 31,2024
Schedule 6-Functionalized and Classified Rate Base and Revenue Requirement,and Unit Costs by Customer Class
Transport Service Transport Service
Line Description TOTAL Residential Service General Service Large Volume (Interruptible) (Firm)
86 Unit Costs
87 Storage
88 Demand $ 0.03 $ 0.03 $ 0.03 $ 0.03 $ $ 0.03
89 Commodity $ - $ - $ - $ - $ $ -
90 Customer $ - $ - $ - $ - $ $ -
91 Transmission
92 Demand $ 0.12 $ 0.12 $ 0.12 $ 0.12 $ $ 0.12
93 Commodity $ - $ - $ - $ - $ $ -
94 Customer $ - $ - $ - $ - $ $ -
95 Distribution
96 Demand $ 0.29 $ 0.28 $ 0.28 $ 0.31 $ $ 0.30
97 Commodity $ - $ - $ - $ - $ - $ -
98 Customer $ 7.68 $ 7.30 $ 9.51 $ 409.28 $ 631.55 $ 602.27
99 Customer
100 Demand $ $ - $ - $ - $ - $ -
101 Commodity $ $ - $ - $ - $ - $ -
102 Customer $ 14.43 $ 13.03 $ 24.77 $ 908.52 $ 1,248.13 $ 1,295.56
115 Total
116 Commodity $ - $ - $ - $ - $ - $ -
117 Customer(per cust month) $ 22.10 $ 20.33 $ 34.28 $ 1,317.80 $ 1,879.68 $ 1,897.83
118 Demand&Customer(per cust month) $ 28.66 $ 24.12 $ 51.34 $ 2,295.90 $ 2,101.02 $ 8,434.11
119 BILLING DETERMINANTS
1.20 Demand(Peak Day Demand*12) 80,379,423 43,185,302 17,891,701 984,060 0 18,318,360
121 Energy 857,517,633 309,250,607 148,742,341 15,440,184 38,382,448 345,702,053
122 Customers(Number of Bills) 5,283,196 4,835,532 445,840 456 108 1,260
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.35
Page 32 of 32

Preston N. Carter, ISB No. 8462
Megann E. Meier, ISB No. 11948
GIVENS PURSLEY LLP
601 West Bannock Street
P.O. Box 2720
Boise, Idaho 83701-2720
Office: [phone]
Fax: [phone]
[e-mail]
[e-mail]
Attorneys for Intermountain Gas Company
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF THE APPLICATION Case No. INT-G-25-02
OF INTERMOUNTAIN GAS COMPANY
FOR THE AUTHORITY TO INCREASE
ITS RATES AND CHARGES FOR
NATURAL GAS SERVICE IN THE STATE
OF IDAHO
EXHIBIT 36 TO ACCOMPANY THE
DIRECT TESTIMONY OF RON AMEN

Intermountain Gas Company
Gas Class Cost of Service Study Test Year Ended December 31,
2024 Exhibit 36-Proposed Revenue Targets
Line Transport Service Transport Service
No. Category Description Total System Residential Service General Service Large Volume (Interruptible) (Firm)
1 Total Rate Base $ 578,473,094 $ 442,538,480 $ 89,845,602 $ 3,717,614 $ 574,349 $ 41,797,050
2 Gas Service Revenue $ 119,595,328 $ 79,817,679 $ 28,264,261 $ 777,024 $ 563,913 $ 10,172,451
3 Other Revenues 5,320,360 4,097,921 804,273 36,787 7,973 373,406
4 Total Revenue $ 124,915,688 $ 83,915,600 $ 29,068,534 $ 813,811 $ 571,886 $ 10,545,857
5 Current Revenue to Cost Ratio 0.82 0.72 1.27 0.78 2.52 0.99
6 Current Parity Ratio 1.00 0.87 1.54 0.94 3.05 1.20
7 Scenario 1:Revenues at Equalized Rates of Return
8 Margin Revenue Increase/(Decrease) $ 26,499,489 $ 32,709,480 $ (6,179,260) $ 233,121 $ (344,976) $ 81,124
9 Total Rate Revenue at Equalized Rates of Return $ 146,094,817 $ 112,527,159 $ 22,085,001 $ 1,010,145 $ 218,937 $ 10,253,575
10 Other Revenues 5,320,360 4,097,921 804,273 36,787 7,973 373,406
11 Total Revenue at Equalized Rates of Return $ 151,415,177 $ 116,625,079 $ 22,889,275 $ 1,046,932 $ 226,910 $ 10,626,981
12 %Increase of Total Revenues 21.2% 39.0% -21.3% 28.6% -60.3% 0.8%
13 %Increase of Margin Revenues 22.2% 41.0% -21.9% 30.0% -61.2% 0.8%
14 Resulting Revenue to Cost Ratio(Parity Ratio) 1.00 1.00 1.00 1.00 1.00 1.00
15 Scenario 2:Equal Percentage Increase on Service Revenue
16 Percent Increase 22.2% 22.2% 22.2% 22.2% 22.2% 22.2%
17 Revenue Increase/(Decrease) $ 26,499,489 $ 17,685,705 $ 6,262,690 $ 172,170 $ 124,950 $ 2,253,974
18 Total Rate Revenue 146,094,817 97,503,384 34,526,951 949,194 688,863 12,426,425
19 Other Revenues 5,320,360 4,097,921 804,273 36,787 7,973 373,406
20 Total Revenue at Equal Percentage Increase $ 151,415,177 $ 101,601,305 $ 35,331,224 $ 985,981 $ 696,836 $ 12,799,831
21 Resulting Revenue to Cost Ratio(Parity Ratio) 1.00 0.87 1.54 0.94 3.07 1.20
22 Scenario 3:Moderated based on Current Parity Ratio
23 Multiple of System Increase 1.20 0.59 1.20 0.25 0.59
24 Percent Increase 26.59% 13.11% 26.59% 5.54% 13.11%
25 Revenue Increase/(Decrease) $ 26,499,489 $ 21,222,846 $ 3,705,260 $ 206,604 $ 31,237 $ 1,333,542
26 Total Rate Revenue 146,094,817 101,040,525 31,969,521 983,628 595,150 11,505,993
27 Other Revenues $ 5,320,360 $ 4,097,921 $ 804,273 $ 36,787 $ 7,973 $ 373,406
28 Total Revenue at Proposed $ 151,415,177 $ 105,138,446 $ 32,773,794 $ 1,020,415 $ 603,124 $ 11,879,399
29 Base Rate Margin at Proposed $ 146,094,817 $ 101,040,525 $ 31,969,521 $ 983,628 $ 595,150 $ 11,505,993
30 Percent Increase on Base Rate Margin 22.16% 26.59% 13.11% 26.59% 5.54% 13.11%
31 Resulting Revenue to Cost Ratio(Parity Ratio) 1.00 0.90 1.43 0.97 2.66 1.12
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 36
Page 1 of I

Preston N. Carter, ISB No. 8462
Megann E. Meier, ISB No. 11948
GIVENS PURSLEY LLP
601 West Bannock Street
P.O. Box 2720
Boise, Idaho 83701-2720
Office: [phone]
Fax: [phone]
[e-mail]
[e-mail]
Attorneys for Intermountain Gas Company
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF THE APPLICATION Case No. INT-G-25-02
OF INTERMOUNTAIN GAS COMPANY
FOR THE AUTHORITY TO INCREASE
ITS RATES AND CHARGES FOR
NATURAL GAS SERVICE IN THE STATE
OF IDAHO
EXHIBIT 37 TO ACCOMPANY THE
DIRECT TESTIMONY OF RON AMEN

Intermountain Gas Company
Exhibit 37-Proposed Rate Design and Proof of Revenue
Residential-STEP 1 RATES
Billing Current Base Rates Proposed Step 1 Base Rates Difference
Description Units Determinants Rates Revenues Rates Revenues $
RS_RESIDENTIAL SERVICE
Customer Charge Customer Bills 4,831,416 $ 8.00 $ 38,651,328 $ 14.00 $ 67,639,824 $ 28,988,496 75.00%
Distribution Charge Therms 308,569,141 $ 0.13301 41,042,781 $ 0.10782 33,269,925 (7,772,857) -18.94%
Total COG Therms 308,569,141 $ 0.40358 124,532,334 $ 0.40358 124,532,334 0.00%
Energy Efficiency Therms 308,569,141 $ 0.01149 3,545,459 $ 0.01149 3,545,459 0.00%
Total Revenues $ 207,771,903 $ 228,987,542 $ 21,215,639 10.21%
IS-R RESIDENTIAL INTERRUPTIBLE SNOWMELT SERVICE
Customer Charge Customer Bills 4,116 $ 8.00 $ 32,928 $ 14.00 $ 57,624 $ 24,696 75.00%
Distribution Charge Therms 681,467 $ 0.13301 90,642 $ 0.10782 73,476 (17,166) -18.94%
Total COG Therms 681,467 $ 0.40358 275,026 $ 0.40358 275,026 - 0.00%
Total Revenues $ 398,596 $ 406,126 $ 7,530 1.89%
Total Customer Charge Revenue Cust $ 38,684,256 $ 67,697,448 $ 29,013,192 75.00%
Total Distribution Charge Revenue Therms 41,133,423 33,343,400 (7,790,023) -18.94%
Total Gas Cost Revenue 124,807,360 124,807,360 0.00%
Total Energy Efficiency Rider Revenue 3,545,459 3,545,459 0.00%
Total Revenues $ 208,170,499 $ 229,393,668 $ 21,223,169 10.20%
Target Base Revenue
$101,040,525
Customer Bills 4,831,416 $ 8.00 $ 38,651,328 $ 14.00 $ 67,639,824 $28,988,496 75.00%
Customer Bills 4,116 $ 8.00 32,928 $ 14.00 57,624 24,696 75.00%
Therms 309,250,607 $ 0.13301 $ 41,133,423 $ 0.10782 $ 33,343,077 ($7,790,346) -18.94%
Total Base Revenue $ 79,817,679 $ 101,040,525 $ 21,222,846 26.59%
Total Gas Cost Revenue $ 124,807,360 $ 124,807,360 $ -
Total Energy Efficiency Rider Revenue 3,545,459 3,545,459 -
Total Revenue $ 208,170,499 $ 229,393,345 $ 21,222,846 10.20%
Target Revenue Difference(due to rounding) $ 323
Target Revenue Difference% 0.00%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 37
Pagel of 8

Intermountain Gas Company
Exhibit 37-Proposed Rate Design and Proof of Revenue
Residential-STEP 2 RATES
Billing Proposed Step 1 Base Rates Proposed Step 2 Base Rates Difference
Description Units Determinants Rates Revenues Rates Revenues $
RS_RESIDENTIAL SERVICE
Customer Charge Customer Bills 4,831,416 $ 14.00 $ 67,639,824 $ 20.00 $ 96,628,320 $ 28,988,496 42.86%
Distribution Charge Therms 308,569,141 $ 0.10782 33,269,925 $ 0.01400 4,319,968 (28,949,957) -87.02%
Total COG Therms 308,569,141 $ 0.40358 124,532,334 $ 0.40358 124,532,334 0.00%
Energy Efficiency Therms 308,569,141 $ 0.01149 3,545,459 $ 0.01149 3,545,459 0.00%
Total Revenues $ 228,987,542 $ 229,026,081 $ 38,539 0.02%
IS-R RESIDENTIAL INTERRUPTIBLE SNOWMELT SERVICE
Customer Charge Customer Bills 4,116 $ 14.00 $ 57,624 $ 20.00 $ 82,320 $ 24,696 42.86%
Distribution Charge Therms 681,467 $ 0.10782 73,476 $ 0.01400 9,541 (63,935) -87.02%
Total COG Therms 681,467 $ 0.40358 275,026 $ 0.40358 275,026 - 0.00%
Total Revenues $ 406,126 $ 366,887 $ (39,239) -9.66%
Total Customer Charge Revenue Cust $ 67,697,448 $ 96,710,640 $ 29,013,192 42.86%
Total Distribution Charge Revenue Therms 33,343,400 4,329,509 (29,013,892) -87.02%
Total Gas Cost Revenue 124,807,360 124,807,360 0.00%
Total Energy Efficiency Rider Revenue 3,545,459 3,545,459 0.00%
Total Revenues $ 229,393,668 $ 229,392,968 $ (700) 0.00%
Target Base Revenue
$101,040,525
Customer Bills 4,831,416 $ 14.00 $ 67,639,824 $ 20.00 $ 96,628,320 $28,988,496 42.86%
Customer Bills 4,116 $ 14.00 57,624 $ 20.00 82,320 24,696 42.86%
Therms 309,250,607 $ 0.10782 $ 33,343,400 $ 0.01400 $ 4,329,885 ($29,013,515) -87.01%
Total Base Revenue $ 101,040,848 $ 101,040,525 $ (323) 0.00%
Total Gas Cost Revenue $ 124,807,360 $ 124,807,360 $ -
Total Energy Efficiency Rider Revenue 3,545,459 3,545,459 -
Total Revenue $ 229,393,668 $ 229,393,345 $ (323) 0.00%
Target Revenue Difference(due to rounding) $ (377)
Target Revenue Difference% 0.00%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 37
Page 2 of 8

Intermountain Gas Company
Exhibit 37-Proposed Rate Design and Proof of Revenue
General Service
Billing Current Base Rates Proposed Base Rates Difference
Description Units Determinants Rates Revenues Rates Revenues $ %
GS-1 GENERAL SERVICE
Customer Charge Customer Bills 444,756 $ 15.00 $ 6,671,340 $ 40.00 $ 17,790,240 $ 11,118,900 166.67%
Block 1-First 200 therms per bill Therms 39,943,198 $ 0.16885 $ 6,744,409 $ 0.11061 $ 4,418,117 $ (2,326,292) -34.49%
Block 2-Next 1,800 therms per bill Therms 71,568,655 $ 0.14738 10,547,788 $ 0.09654 6,909,238 (3,638,550) -34.50%
Block 3-Next 8,000 therms per bill Therms 29,669,663 $ 0.12665 3,757,663 $ 0.08296 2,461,395 (1,296,268) -34.50%
Block 4-Over 10,000 therms per bill Therms 7,009,068 $ 0.06396 448,300 $ 0.04190 293,680 (154,620) -34.49%
148,190,583 $ 21,498,160 $ 14,082,430 $ (7,415,730) -34.50%
Total COG Therms 148,190,583 $ 0.38615 $ 57,223,794 $ 0.38615 $ 57,223,794 $ 0.00%
Energy Efficiency Therms 148,190,583 $ - - $ - - 0.00%
Total Revenues $ 85,393,294 $ 89,096,464 $ 3,703,170 4.34%
GS-1 IRRIGATION CUSTOMERS
Customer Charge Customer Bills 76 $ 15.00 $ 1,140 $ 40.00 $ 3,040 $ 1,900.00 166.67%
Block 1-First 200 therms per bill Therms 8,554 $ 0.16885 $ 1,444 $ 0.11061 $ 946 $ (498.18) -34.49%
Block 2-Next 1,800 therms per bill Therms 31,170 $ 0.14738 4,594 $ 0.09654 3,009 (1,584.68) -34.50%
Block 3-Next 8,000 therms per bill Therms 5,504 $ 0.12665 697 $ 0.08296 457 (240.47) -34.50%
Block 4-Over 10,000 therms per bill Therms - $ 0.06396 - $ 0.04190 0.00%
45,228 $ 6,735 $ 4,412 $ (2,323.34) -34.50%
Total COG Therms 45,228 $ 0.38615 $ 17,465 $ 0.38615 $ 17,465 $ 0.00%
Energy Efficiency Therms 45,228 $ - - $ - - 0.00%
Total Revenues $ 25,340 $ 24,917 $ (423) -1.67%
GS-1 COMPRESSED NATURAL GAS
Customer Charge Customer Bills - $ 15.00 $ - $ 40.00 $ - $ - 0.00%
Block 1-First 10,000 therms per bill Therms $ 0.12665 $ 0.08296 0.00%
Block 2-Over 10,000 therms per bill Therms $ 0.06396 $ 0.04190 0.00%
$ $ $ 0.00%
Total COG Therms $ 0.38615 $ $ 0.38615 $ $ 0.00%
Total Revenues $ $ $ 0.00%
IS-C SMALL COMMERCIAL INTERRUPTIBLE SNOWMELT SERVICE
Customer Charge Customer Bills 1,008 $ 12.50 $ 12,600 $ 40.00 $ 40,320 $ 27,720.0 220.00%
Block 1-First 200 therms per bill Therms 98,755 $ 0.16885 $ 16,675 $ 0.11061 $ 10,923 $ (5,751) -34.49%
Block 2-Next 1,800 therms per bill Therms 287,823 $ 0.14738 42,419 $ 0.09654 27,786 (14,633) -34.50%
Block 3-Next 8,000 therms per bill Therms 119,951 $ 0.12665 15,192 $ 0.08296 9,951 (5,241) -34.50%
Block 4-Over 10,000 therms per bill Therms - $ 0.06396 - $ 0.04190 - - 0.00%
506,529 $ 74,286 $ 48,661 $ (25,625) -34.50%
Total COG Therms 506,529 $ 0.38615 $ 195,596 $ 0.38615 $ 195,596 $ - 0.00%
Total Revenues $ 282,482 $ 284,577 $ 2,095
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.37
Page 3 of 8

Intermountain Gas Company
Exhibit 37-Proposed Rate Design and Proof of Revenue
General Service
Billing Current Base Rates Proposed Base Rates Difference
Description Units Determinants Rates Revenues Rates Revenues $ %
General Service Total:
Customer Charge Customer Bills 445,840 $ 6,685,080 $ 17,833,600 $ 11,148,520 166.77%
Block 1-First 200 therms per bill Therms 40,050,507 6,762,528 4,429,987 (2,332,542) -34.49%
Block 2-Next 1,800 therms per bill Therms 71,887,647 10,594,801 6,940,033 (3,654,768) -34.50%
Block 3-Next 8,000 therms per bill Therms 29,795,118 3,773,552 2,471,803 (1,301,749) -34.50%
Block 4-Over 10,000 therms per bill Therms 7,009,068 448,300 293,680 (154,620) -34.49%
Total COG Therms 148,742,341 57,436,855 57,436,855 0.00%
Energy Efficiency Therms 148,235,811 - - 0.00%
Total Revenues $ 85,701,116 $ 89,405,958 $ 3,704,842 4.32%
Target Base Revenue
$31,969,521
Customer Charge Customer Bills 444,832 $ 15.00 $ 6,672,480 $ 40.00 $ 17,793,280 $ 11,120,800 166.67%
Customer Charge-Interruptible Customer Bills 1,008 $ 12.50 12,600 $ 40.00 $ 40,320 $ 27,720 220.00%
Block 1-First 200 therms per bill Therms 40,050,507 $ 0.16885 $ 6,762,528 $ 0.11061 $ 4,429,944 $ (2,332,584) -34.49%
Block 2-Next 1,800 therms per bill Therms 71,887,647 0.14738 10,594,801 0.09654 6,940,359 (3,654,442) -34.49%
Block 3-Next 8,000 therms per bill Therms 29,795,118 0.12665 3,773,552 0.08296 2,471,949 (1,301,603) -34.49%
Block 4-Over 10,000 therms per bill Therms 7,009,068 0.06396 448,300 0.04190 293,669 (154,631) -34.49%
148,742,341 $ 21,579,181 $ 14,135,921 $ (7,443,260) -34.49%
Total Base Revenue $ 28,264,261 $ 31,969,521 $ 3,705,260 13.11%
Total Gas Cost Revenue $ 57,436,855 $ 57,436,855 $ -
Total Energy Efficiency Rider Revenue - - -
Total Revenue $ 85,701,116 $ 89,406,375 $ 3,705,260 4.32%
Target Revenue Difference(due to rounding) $ (418)
Target Revenue Difference% 0.00%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No.37
Page 4 of 8

Intermountain Gas Company
Exhibit 37-Proposed Rate Design and Proof of Revenue
Large Volume
Billing Current Base Rates Proposed Base Rates Difference
Description Units Determinants Rates Revenues Rates Revenues $
LV-1 LARGE VOLUME
Customer Charge Customer Bills 456 $ 150.00 $ 68,400 $ 375.00 $ 171,000 $ 102,600 150.00%
Demand Charge Demand(Therm) 984,060 $ 0.3200 $ 314,899 $ 0.44000 $ 432,986 $ 118,087 37.50%
Overrun Demand Charge Demand(Therm) 34,448 $ 0.3200 $ 11,023 $ 0.44000 $ 15,157 $ 4,134 37.50%
Block 1-First 35,000 therms per bill Therms 11,203,517 $ 0.03000 $ 336,106 $ 0.02857 $ 320,084 $ (16,021) -4.77%
Block 2-Next 35,000 therms per bill Therms 3,419,788 $ 0.01187 40,593 0.01130 38,644 (1,949) -4.80%
Block 3-Over 70,000 therms per bill Therms 816,879 $ 0.00735 6,004 0.00700 5,718 (286) -4.76%
All Volumes 15,440,184 $ 382,702 $ 364,446 $ (18,256) 0.00%
Total COG Therms 15,440,184 $ 0.32435 $ 5,008,024 0.32435 $ 5,008,024 $ - 0.00%
Total Revenues $ 5,785,049 $ 5,991,614 $ 206,565 3.57%
Target Base Revenue $ 983,628
Total Gas Cost Revenue $ 5,008,024
Total Revenue Target $ 5,991,652
Target Revenue Difference(due to rounding) (38)
Target Revenue Difference% 0.00%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 37
Page 5 of 8

Intermountain Gas Company
Exhibit 37-Proposed Rate Design and Proof of Revenue
Transportation
Billing Current Base Rates Proposed Base Rates Difference
Description Units Determinants Rates Revenues Rates Revenues $ %
T-3-TRANSPORT INTERRUPTIBLE
Customer Charge Customer Bills 108 $ 300.00 $32,400 $ 600.00 $ 64,800 $ 32,400 100.00%
Block 1-First 100,000 therms per bill Therms 9,153,504 $ 0.03694 $ 338,130 $ 0.03686 $ 337,398 $ (732) -0.22%
Block 2-Next 50,000 therms per bill Therms 3,310,904 0.01504 49,796 0.01501 49,697 (99) -0.20%
Block 3-Over 150,000 therms per bill Therms 25,918,040 0.00554 143,586 0.00553 143,327 (259) -0.18%
All Volume 38,382,448 $ 531,512 $ 530,422 $ (1,091) -0.21%
Total COG Therms 38,382,448 $ (0.00205) $ (78,684) (0.00205) $ (78,684) $ - 0.00%
Total Base Revenues $ 485,228 $ 516,538 $ 31,309 6.45%
Target Revenue 595,150
Total Gas Cost Revenue $ (78,684)
Total Revenue Target $ 516,466
Target Revenue Difference(due to rounding) 71
Target Revenue Difference% 0.01%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 37
Page 6 of 8

Intermountain Gas Company
Exhibit 37-Proposed Rate Design and Proof of Revenue
Transportation
Billing Current Base Rates Proposed Base Rates Difference
Description Units Determinants Rates Revenues Rates Revenues $
T-4-TRANSPORT FIRM
Customer Charge Customer Bills 1,260 $ 150.00 $ 189,000 $ 300.00 $ 378,000 $ 189,000 100.00%
Total Revenues
Demand Charge Demand(Therm) 18,354,360 $ 0.3200 $ 5,873,395 $ 0.44000 $ 8,075,918 $ 2,202,523 37.50%
Overrun Demand Charge Demand(Therm) 468,953 $ 0.3200 $ 150,065 $ 0.44000 $ 206,339 $ 56,274 37.50%
Block 1-First 250,000 therms per bill Therms 133,107,242 $ 0.02172 $ 2,891,089 $ 0.01561 $ 2,077,804 $ (813,285) -28.13%
Block 2-Next 500,000 therms per bill Therms 106,612,320 0.00768 818,783 0.00552 588,500 (230,283) -28.13%
Block 3-Over 750,000 therms per bill Therms 105,982,491 0.00236 250,119 0.00169 179,110 (71,008) -28.39%
All Volumes 345,702,053 $ 3,959,991 $ 2,845,414 $ (1,114,576) -28.15%
Other Temps Demand(Therm) 18,354,360 $ (0.05586) $ (1,025,275) $ (0.05586) $ (1,025,275) $ - 0.00%
Total Revenues $ 9,147,176 $ 10,480,398 $ 1,333,222 14.58%
Target Base Revenue $ 11,505,993
Total Other Temps $ (1,025,275)
Total Revenue $ 10,480,718
Target Revenue Difference(due to rounding) (321)
Target Revenue Difference% 0.00%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 37
Page 7 of 8

Intermountain Gas Company
Exhibit 37-Proposed Rate Design and Proof of Revenue
Summary of Rate Schedule Revenues
Line Rate Schedule Description Current Revenue Proposed Revenue Revenue Change Percent Change
1 RS_RESIDENTIAL SERVICE(Step 1)
2 Customer Charge Revenue $ 38,651,328 $ 67,639,824 $ 28,988,496 75.00%
3 Distribution Charge Revenue 41,042,781 33,269,925 (7,772,857) -18.94%
4 Gas Cost Revenue 124,532,334 124,532,334 0.00%
5 Energy Efficiency Rider 3,545,459 3,545,459 - 0.00%
6 Total Rate Revenue $ 207,771,903 $ 228,987,542 $ 21,215,639 10.21%
7 IS-R_RESIDENTIAL INTERRUPTIBLE SNOWMELT SERVICE
8 Customer Charge Revenue $ 32,928 $ 57,624 $ 24,696 75.00%
9 Distribution Charge Revenue 90,642 73,476 (17,166) -18.94%
10 Gas Cost Revenue 275,026 275,026 - 0.00%
11 Total Rate Revenue $ 398,596 $ 406,126 $ 7,530 1.89%
12 GS-1_GENERALSERVICE
13 Customer Charge Revenue $ 6,671,340 $ 17,790,240 $ 11,118,900 166.67%
14 Distribution Charge Revenue 21,498,160 14,082,430 (7,415,730) -34.50%
15 Gas Cost Revenue 57,223,794 57,223,794 0.00%
16 Energy Efficiency Rider - - - 0.00%
17 Total Rate Revenue $ 85,393,294 $ 89,096,464 $ 3,703,170 4.34%
18 GS-1_IRRIGATION CUSTOMERS
19 Customer Charge Revenue $ 1,140 $ 3,040 $ 1,900 166.67%
20 Distribution Charge Revenue 6,735 4,412 (2,323) -34.50%
21 Gas Cost Revenue 17,465 17,465 0.00%
22 Energy Efficiency Rider - - - 0.00%
23 Total Rate Revenue $ 25,340 $ 24,917 $ (423) -1.67%
24 GS-1_COMPRESSED NATURAL GAS
25 Customer Charge Revenue $ - $ - $ - 0.00%
26 Distribution Charge Revenue 0.00%
27 Gas Cost Revenue 0.00%
28 Total Rate Revenue $ - $ - $ - 0.00%
29 IS-C_SMALL COMMERCIAL INTERRUPTIBLE SNOWMELT SERVICE
30 Customer Charge Revenue $ 12,600 $ 40,320 $ 27,720 220.00%
31 Distribution Charge Revenue 74,286 48,661 (25,625) -34.50%
32 Gas Cost Revenue 195,596 195,596 - 0.00%
33 Total Rate Revenue $ 282,482 $ 284,577 $ 2,095 0.74%
34 LV-1_LARGE VOLUME
35 Customer Charge Revenue $ 68,400 $ 171,000 $ 102,600 150.00%
36 Demand Charge Revenue 325,923 448,144 122,221 31.94%
37 Distribution Charge Revenue 382,702 364,446 (18,256) -5.60%
38 Gas Cost Revenue 5,008,024 5,008,024 - 0.00%
39 Total Rate Revenue $ 5,785,049 $ 5,991,614 $ 206,565 3.57%
40 T-3-TRANSPORT INTERRUPTIBLE
41 Customer Charge Revenue $ 32,400 $ 64,800 $ 32,400 100.00%
42 Distribution Charge Revenue 531,512 530,422 (1,091) -0.21%
43 Gas Cost Revenue (78,684) (78,684) - 0.00%
44 Total Rate Revenue $ 485,228 $ 516,538 $ 31,309 6.45%
45 T-4-TRANSPORT FIRM
46 Customer Charge Revenue $ 189,000 $ 378,000 $ 189,000 100.00%
47 Demand Charge Revenue 6,023,460 8,282,258 2,258,798 37.50%
48 Distribution Charge Revenue 3,959,991 2,845,414 (1,114,576) -28.15%
49 Gas Cost Revenue (1,025,275) (1,025,275) - 0.00%
50 Total Rate Revenue $ 9,147,176 $ 10,480,398 $ 1,333,222 14.58%
51 TOTAL COMPANY RATE REVENUE SUMMARY
52 Customer Charge Revenue $ 45,659,136 $ 86,144,848 $ 40,485,712 88.67%
53 Demand Charge Revenue 6,349,383 8,730,401 2,381,019 37.50%
54 Distribution Charge Revenue 67,586,810 51,219,186 (16,367,624) -24.22%
55 Gas Cost Revenue 186,148,280 186,148,280 0.00%
56 Energy Efficiency Rider 3,545,459 3,545,459 - 0.00%
57 Total Rate Revenue $ 309,289,068 $ 335,788,175 $ 26,499,106 Case Nd:5MT-G-25-02
R.Amen,IGC
Exhibit No.37
Page 8 of 8

Preston N. Carter, ISB No. 8462
Megann E. Meier, ISB No. 11948
GIVENS PURSLEY LLP
601 West Bannock Street
P.O. Box 2720
Boise, Idaho 83701-2720
Office: [phone]
Fax: [phone]
[e-mail]
[e-mail]
Attorneys for Intermountain Gas Company
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF THE APPLICATION Case No. INT-G-25-02
OF INTERMOUNTAIN GAS COMPANY
FOR THE AUTHORITY TO INCREASE
ITS RATES AND CHARGES FOR
NATURAL GAS SERVICE IN THE STATE
OF IDAHO
EXHIBIT 38 TO ACCOMPANY THE
DIRECT TESTIMONY OF RON AMEN

Intermountain Gas Company
Exhibit 38-Bill Impact
Residential-STEP 1 RATES
RS-RESIDENTIAL SERVICE
CURRENT PROPOSED
RATES STEP-1 RATES
CUSTOMER CHARGE $ 8.00 $ 14.00
DISTRIBUTION CHARGE $0.13301 $0.10782
Total COG $0.40358 $0.40358
Energy Efficiency $0.01149 $0.01149
Property Tax $0.00000 $0.00329
DIFFERENCE
THERMS CURRENT PROPOSED AMOUNT PERCENT
0 8.00 14.00 6.00 75.00%
10 13.48 19.26 5.78 42.88%
20 18.96 24.52 5.56 29.33%
30 24.44 29.79 5.34 21.86%
40 29.92 35.05 5.12 17.12%
50 35.40 40.31 4.90 13.85%
(1) 60 40.88 45.57 4.69 11.46%
70 46.37 50.83 4.47 9.63%
80 51.85 56.09 4.25 8.19%
90 57.33 61.36 4.03 7.03%
100 62.81 66.62 3.81 6.07%
110 68.29 71.88 3.59 5.26%
120 73.77 77.14 3.37 4.57%
130 79.25 82.40 3.15 3.98%
140 84.73 87.67 2.93 3.46%
150 90.21 92.93 2.71 3.01%
160 95.69 98.19 2.50 2.61%
170 101.17 103.45 2.28 2.25%
180 106.65 108.71 2.06 1.93%
190 112.14 113.97 1.84 1.64%
200 117.62 119.24 1.62 1.38%
210 123.10 124.50 1.40 1.14%
220 128.58 129.76 1.18 0.92%
230 134.06 135.02 0.96 0.72%
240 139.54 140.28 0.74 0.53%
250 145.02 145.55 0.52 0.36%
260 150.50 150.81 0.31 0.20%
270 155.98 156.07 0.09 0.06%
280 161.46 161.33 (0.13) -0.08%
290 166.94 166.59 (0.35) -0.21%
300 172.42 171.85 (0.57) -0.33%
(1) RS_Residential Service average monthly usage
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 1 of 12

Intermountain Gas Company
Exhibit 38-Bill Impact
Residential-STEP 2 RATES
RS-RESIDENTIAL SERVICE
PROPOSED PROPOSED
STEP-1 RATES STEP-2 RATES
CUSTOMER CHARGE $ 14.00 $ 20.00
DISTRIBUTION CHARGE $0.10782 $0.01400
Total COG $0.40358 $0.40358
Energy Efficiency $0.01149 $0.01149
Property Tax $0.00329 $0.00329
DIFFERENCE
THERMS CURRENT PROPOSED AMOUNT PERCENT
0 14.00 20.00 6.00 42.86%
10 19.26 24.32 5.06 26.28%
20 24.52 28.65 4.12 16.81%
30 29.79 32.97 3.19 10.69%
40 35.05 37.29 2.25 6.41%
50 40.31 41.62 1.31 3.25%
(1) 60 45.57 45.94 0.37 0.81%
70 50.83 50.27 (0.57) -1.12%
80 56.09 54.59 (1.51) -2.68%
90 61.36 58.91 (2.44) -3.98%
100 66.62 63.24 (3.38) -5.08%
110 71.88 67.56 (4.32) -6.01%
120 77.14 71.88 (5.26) -6.82%
130 82.40 76.21 (6.20) -7.52%
140 87.67 80.53 (7.13) -8.14%
150 92.93 84.85 (8.07) -8.69%
160 98.19 89.18 (9.01) -9.18%
170 103.45 93.50 (9.95) -9.62%
180 108.71 97.82 (10.89) -10.02%
190 113.97 102.15 (11.83) -10.38%
200 119.24 106.47 (12.76) -10.70%
210 124.50 110.80 (13.70) -11.01%
220 129.76 115.12 (14.64) -11.28%
230 135.02 119.44 (15.58) -11.54%
240 140.28 123.77 (16.52) -11.77%
250 145.55 128.09 (17.46) -11.99%
260 150.81 132.41 (18.39) -12.20%
270 156.07 136.74 (19.33) -12.39%
280 161.33 141.06 (20.27) -12.56%
290 166.59 145.38 (21.21) -12.73%
300 171.85 149.71 (22.15) -12.89%
(1) RS_Residential Service average monthly usage
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 2 of 12

Intermountain Gas Company
Exhibit 38-Bill Impact
Residential-STEP 2 RATES versus Current Rates
RS-RESIDENTIAL SERVICE
CURRENT PROPOSED
RATES STEP-2 RATES
CUSTOMER CHARGE $ 8.00 $ 20.00
DISTRIBUTION CHARGE $0.13301 $0.01400
Total COG $0.40358 $0.40358
Energy Efficiency $0.01149 $0.01149
Property Tax $0.00000 $0.00329
DIFFERENCE
THERMS CURRENT PROPOSED AMOUNT PERCENT
0 8.00 20.00 12.00 150.00%
10 13.48 24.32 10.84 80.43%
20 18.96 28.65 9.69 51.08%
30 24.44 32.97 8.53 34.89%
40 29.92 37.29 7.37 24.63%
50 35.40 41.62 6.21 17.55%
(1) 60 40.88 45.94 5.06 12.37%
70 46.37 50.27 3.90 8.41%
80 51.85 54.59 2.74 5.29%
90 57.33 58.91 1.59 2.77%
100 62.81 63.24 0.43 0.68%
110 68.29 67.56 (0.73) -1.07%
120 73.77 71.88 (1.89) -2.56%
130 79.25 76.21 (3.04) -3.84%
140 84.73 80.53 (4.20) -4.96%
150 90.21 84.85 (5.36) -5.94%
160 95.69 89.18 (6.52) -6.81%
170 101.17 93.50 (7.67) -7.58%
180 106.65 97.82 (8.83) -8.28%
190 112.14 102.15 (9.99) -8.91%
200 117.62 106.47 (11.14) -9.47%
210 123.10 110.80 (12.30) -9.99%
220 128.58 115.12 (13.46) -10.47%
230 134.06 119.44 (14.62) -10.90%
240 139.54 123.77 (15.77) -11.30%
250 145.02 128.09 (16.93) -11.67%
260 150.50 132.41 (18.09) -12.02%
270 155.98 136.74 (19.24) -12.34%
280 161.46 141.06 (20.40) -12.64%
290 166.94 145.38 (21.56) -12.91%
300 172.42 149.71 (22.72) -13.17%
(1) RS_Residential Service average monthly usage
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 3 of 12

Intermountain Gas Company
Exhibit 38-Bill Impact
Residential-STEP 1 RATES
IS-R_RESIDENTIAL INTERRUPTIBLE SNOWMELT SERVICE
CURRENT PROPOSED
RATES STEP-1 RATES
CUSTOMER CHARGE $ 8.00 $ 14.00
DISTRIBUTION CHARGE $0.13301 $0.10782
Total COG $0.40358 $0.40358
Property Tax $0.00000 $0.00329
DIFFERENCE
THERMS CURRENT PROPOSED AMOUNT PERCENT
0 8.00 14.00 6.00 75.00%
10 13.37 19.15 5.78 43.25%
20 18.73 24.29 5.56 29.69%
30 24.10 29.44 5.34 22.17%
40 29.46 34.59 5.12 17.39%
50 34.83 39.73 4.90 14.08%
60 40.20 44.88 4.69 11.66%
70 45.56 50.03 4.47 9.80%
80 50.93 55.18 4.25 8.34%
90 56.29 60.32 4.03 7.16%
100 61.66 65.47 3.81 6.18%
110 67.02 70.62 3.59 5.36%
120 72.39 75.76 3.37 4.66%
130 77.76 80.91 3.15 4.05%
140 83.12 86.06 2.93 3.53%
150 88.49 91.20 2.71 3.07%
160 93.85 96.35 2.50 2.66%
(1) 170 99.22 101.50 2.28 2.29%
180 104.59 106.64 2.06 1.97%
190 109.95 111.79 1.84 1.67%
200 115.32 116.94 1.62 1.40%
210 120.68 122.08 1.40 1.16%
220 126.05 127.23 1.18 0.94%
230 131.42 132.38 0.96 0.73%
240 136.78 137.53 0.74 0.54%
250 142.15 142.67 0.52 0.37%
260 147.51 147.82 0.31 0.21%
270 152.88 152.97 0.09 0.06%
280 158.25 158.11 (0.13) -0.08%
290 163.61 163.26 (0.35) -0.21%
300 168.98 168.41 (0.57) -0.34%
(1) IS-R_Residential Interruptible Snowmelt Service average monthly usage
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 4 of 12

Intermountain Gas Company
Exhibit 38-Bill Impact
Residential-STEP 2 RATES
IS-R_RESIDENTIAL INTERRUPTIBLE SNOWMELT SERVICE
PROPOSED PROPOSED
STEP-1 RATES STEP-2 RATES
CUSTOMER CHARGE $ 14.00 $ 20.00
DISTRIBUTION CHARGE $0.10782 $0.01400
Total COG $0.40358 $0.40358
Property Tax $0.00329 $0.00329
DIFFERENCE
THERMS CURRENT PROPOSED AMOUNT PERCENT
0 14.00 20.00 6.00 42.86%
10 19.15 24.21 5.06 26.44%
20 24.29 28.42 4.12 16.97%
30 29.44 32.63 3.19 10.82%
40 34.59 36.83 2.25 6.50%
50 39.73 41.04 1.31 3.29%
60 44.88 45.25 0.37 0.83%
70 50.03 49.46 (0.57) -1.13%
80 55.18 53.67 (1.51) -2.73%
90 60.32 57.88 (2.44) -4.05%
100 65.47 62.09 (3.38) -5.17%
110 70.62 66.30 (4.32) -6.12%
120 75.76 70.50 (5.26) -6.94%
130 80.91 74.71 (6.20) -7.66%
140 86.06 78.92 (7.13) -8.29%
150 91.20 83.13 (8.07) -8.85%
160 96.35 87.34 (9.01) -9.35%
(1) 170 101.50 91.55 (9.95)
180 106.64 95.76 (10.89) -10.21%
190 111.79 99.97 (11.83) -10.58%
200 116.94 104.17 (12.76) -10.92%
210 122.08 108.38 (13.70) -11.22%
220 127.23 112.59 (14.64) -11.51%
230 132.38 116.80 (15.58) -11.77%
240 137.53 121.01 (16.52) -12.01%
250 142.67 125.22 (17.46) -12.23%
260 147.82 129.43 (18.39) -12.44%
270 152.97 133.63 (19.33) -12.64%
280 158.11 137.84 (20.27) -12.82%
290 163.26 142.05 (21.21) -12.99%
300 168.41 146.26 (22.15) -13.15%
(1) IS-R_Residential Interruptible Snowmelt Service average monthly usage
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 5 of 12

Intermountain Gas Company
Exhibit 38-Bill Impact
Residential-STEP 2 RATES versus Current Rates
IS-R_RESIDENTIAL INTERRUPTIBLE SNOWMELT SERVICE
CURRENT PROPOSED
RATES STEP-2 RATES
CUSTOMER CHARGE $ 8.00 $ 20.00
DISTRIBUTION CHARGE $0.13301 $0.01400
Total COG $0.40358 $0.40358
Property Tax $0.00000 $0.00329
DIFFERENCE
THERMS CURRENT PROPOSED AMOUNT PERCENT
0 8.00 20.00 12.00 150.00%
10 13.37 24.21 10.84 81.12%
20 18.73 28.42 9.69 51.71%
30 24.10 32.63 8.53 35.39%
40 29.46 36.83 7.37 25.02%
50 34.83 41.04 6.21 17.84%
60 40.20 45.25 5.06 12.58%
70 45.56 49.46 3.90 8.56%
80 50.93 53.67 2.74 5.38%
90 56.29 57.88 1.59 2.82%
100 61.66 62.09 0.43 0.69%
110 67.02 66.30 (0.73) -1.09%
120 72.39 70.50 (1.89) -2.61%
130 77.76 74.71 (3.04) -3.91%
140 83.12 78.92 (4.20) -5.05%
150 88.49 83.13 (5.36) -6.06%
160 93.85 87.34 (6.52) -6.94%
(1) 170 99.22 91.55 (7.67)
180 104.59 95.76 (8.83) -8.44%
190 109.95 99.97 (9.99) -9.08%
200 115.32 104.17 (11.14) -9.66%
210 120.68 108.38 (12.30) -10.19%
220 126.05 112.59 (13.46) -10.68%
230 131.42 116.80 (14.62) -11.12%
240 136.78 121.01 (15.77) -11.53%
250 142.15 125.22 (16.93) -11.91%
260 147.51 129.43 (18.09) -12.26%
270 152.88 133.63 (19.24) -12.59%
280 158.25 137.84 (20.40) -12.89%
290 163.61 142.05 (21.56) -13.18%
300 168.98 146.26 (22.72) -13.44%
(1) IS-R_Residential Interruptible Snowmelt Service average monthly usage
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 6 of 12

Intermountain Gas Company
Exhibit 38-Bill Impact
General Service
GS-1_GENERAL SERVICE
GS-1 IRRIGATION CUSTOMERS
CURRENT PROPOSED
RATES RATES
CUSTOMER CHARGE $ 15.00 $ 40.00
Block 1 200 $0.16885 $0.11061
Block 2 1,800 $0.14738 $0.09654
Block 3 8,000 $0.12665 $0.08296
Block 4 10,000 $0.06396 $0.04190
Total COG $0.38615 $0.38615
Energy Efficiency $0.00000 $0.00000
Property Tax $0.00000 $0.00329
DIFFERENCE
THERM CURRENT PROPOSED AMOUNT PERCENT
Usage Per THERM
- 15.00 40.00 25.00 166.67%
100 70.50 90.01 19.51 27.67%
200 126.00 140.01 14.01 11.12%
(1) 300 179.35 188.61 9.26 5.16%
400 232.71 237.21 4.50 1.93%
500 286.06 285.80 (0.26) -0.09%
(2)1 600 339.41 334.40 (5.01)
700 392.77 383.00 (9.77) -2.49%
800 446.12 431.60 (14.52) -3.25%
900 499.47 480.20 (19.28) -3.86%
1000 552.82 528.79 (24.03) -4.35%
1100 606.18 577.39 (28.79) -4.75%
1200 659.53 625.99 (33.54) -5.09%
1300 712.88 674.59 (38.30) -5.37%
1400 766.24 723.19 (43.05) -5.62%
1500 819.59 771.78 (47.81) -5.83%
1600 872.94 820.38 (52.56) -6.02%
1700 926.30 868.98 (57.32) -6.19%
1800 979.65 917.58 (62.07) -6.34%
1900 1,033.00 966.18 (66.83) -6.47%
2000 1,086.35 1,014.77 (71.58) -6.59%
2100 1,137.63 1,062.01 (75.62) -6.65%
2200 1,188.91 1,109.25 (79.66) -6.70%
2300 1,240.19 1,156.49 (83.70) -6.75%
2400 1,291.47 1,203.73 (87.74) -6.79%
2500 1,342.75 1,250.97 (91.78) -6.84%
2600 1,394.03 1,298.21 (95.82) -6.87%
2700 1,445.31 1,345.45 (99.86) -6.91%
2800 1,496.59 1,392.69 (103.90) -6.94%
2900 1,547.87 1,439.93 (107.94) -6.97%
3000 1,599.15 1,487.17 (111.98) -7.00%
(1) GS-1 Geneneral Service average monthly usage
(2) GS-1 Irrigation Service average monthly usage
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 7 of 12

Intermountain Gas Company
Exhibit 38-Bill Impact
General Service
GS-1 COMPRESSED NATURAL GAS
CURRENT PROPOSED
RATES RATES
CUSTOMER CHARGE $ 15.00 $ 40.00
Block 1 10,000 $0.12665 $0.08296
Block 2 10,000 $0.06396 $0.04190
Total COG $0.38615 $0.38615
Property Tax $0.00000 $0.00329
DIFFERENCE
THERM CURRENT PROPOSED AMOUNT PERCENT
Usage Per THERM
- 15.00 40.00 25.00 166.67%
1000 527.80 512.40 (15.40) -2.92%
2000 1,040.60 984.80 (55.80) -5.36%
3000 1,553.40 1,457.20 (96.20) -6.19%
4000 2,066.20 1,929.60 (136.60) -6.61%
5000 2,579.00 2,402.00 (177.00) -6.86%
6000 3,091.80 2,874.40 (217.40) -7.03%
7000 3,604.60 3,346.80 (257.80) -7.15%
8000 4,117.40 3,819.20 (298.20) -7.24%
9000 4,630.20 4,291.60 (338.60) -7.31%
10000 5,143.00 4,764.00 (379.00) -7.37%
11000 5,593.11 5,195.34 (397.77) -7.11%
12000 6,043.22 5,626.68 (416.54) -6.89%
13000 6,493.33 6,058.02 (435.31) -6.70%
14000 6,943.44 6,489.36 (454.08) -6.54%
15000 7,393.55 6,920.70 (472.85) -6.40%
16000 7,843.66 7,352.04 (491.62) -6.27%
17000 8,293.77 7,783.38 (510.39) -6.15%
18000 8,743.88 8,214.72 (529.16) -6.05%
19000 9,193.99 8,646.06 (547.93) -5.96%
20000 9,644.10 9,077.40 (566.70) -5.88%
21000 10,094.21 9,508.74 (585.47) -5.80%
22000 10,544.32 9,940.08 (604.24) -5.73%
23000 10,994.43 10,371.42 (623.01) -5.67%
24000 11,444.54 10,802.76 (641.78) -5.61%
25000 11,894.65 11,234.10 (660.55) -5.55%
26000 12,344.76 11,665.44 (679.32) -5.50%
27000 12,794.87 12,096.78 (698.09) -5.46%
28000 13,244.98 12,528.12 (716.86) -5.41%
29000 13,695.09 12,959.46 (735.63) -5.37%
30000 14,145.20 13,390.80 (754.40) -5.33%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 8 of 12

Intermountain Gas Company
Exhibit 38-Bill Impact
General Service
IS-C SMALL COMMERCIAL INTERRUPTIBLE SNOWMELT SERVICE
CURRENT PROPOSED
RATES RATES
CUSTOMER CHARGE $ 12.50 $ 40.00
Block 1 200 $0.16885 $0.11061
Block 2 1800 $0.14738 $0.09654
Block 3 8000 $0.12665 $0.08296
Block 4 10000 $0.06396 $0.04190
Total COG $0.38615 $0.38615
Property Tax $0.00000 $0.00329
DIFFERENCE
THERM CURRENT PROPOSED AMOUNT PERCENT
Usage Per THERM
- 12.50 40.00 27.50 220.00%
100 68.00 90.01 22.01 32.36%
200 123.50 140.01 16.51 13.37%
300 176.85 188.61 11.76 6.65%
400 230.21 237.21 7.00 3.04%
(1) 500 283.56 285.80 2.24 0.79%
600 336.91 334.40 (2.51) -0.75%
700 390.27 383.00 (7.27) -1.86%
800 443.62 431.60 (12.02) -2.71%
900 496.97 480.20 (16.78) -3.38%
1000 550.32 528.79 (21.53) -3.91%
1100 603.68 577.39 (26.29) -4.35%
1200 657.03 625.99 (31.04) -4.72%
1300 710.38 674.59 (35.80) -5.04%
1400 763.74 723.19 (40.55) -5.31%
1500 817.09 771.78 (45.31) -5.54%
1600 870.44 820.38 (50.06) -5.75%
1700 923.80 868.98 (54.82) -5.93%
1800 977.15 917.58 (59.57) -6.10%
1900 1,030.50 966.18 (64.33) -6.24%
2000 1,083.85 1,014.77 (69.08) -6.37%
2100 1,135.13 1,062.01 (73.12) -6.44%
2200 1,186.41 1,109.25 (77.16) -6.50%
2300 1,237.69 1,156.49 (81.20) -6.56%
2400 1,288.97 1,203.73 (85.24) -6.61%
2500 1,340.25 1,250.97 (89.28) -6.66%
2600 1,391.53 1,298.21 (93.32) -6.71%
2700 1,442.81 1,345.45 (97.36) -6.75%
2800 1,494.09 1,392.69 (101.40) -6.79%
2900 1,545.37 1,439.93 (105.44) -6.82%
3000 1,596.65 1,487.17 (109.48) -6.86%
(1) IS-C_SMALL COMMERCIAL INTERRUPTIBLE SNOWMELT SERVICE average monthly usage
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 9 of 12

Intermountain Gas Company
Exhibit 38—Bill Impact Large
Volume
LV-1 LARGE VOLUME
Current Block Current Rates Proposed Rates
Customer Charge $ 150.00 $ 375.00
Demand Charge $0.32000 $0.44000
Block 1 35,000 $0.03000 $0.02857
Block 2 35,000 $0.01187 $0.01130
Block 3 70,000 $0.00735 $0.00700
Total COG $0.32435 $0.32435
Property Tax $0.00000 $0.00329
Customer Usage Scenario Monthly Average MDFQ Current Monthly Proposedgill Monthly Bill Difference$ Difference
High Use/High Demand 40,000 6,000 $ 16,153 $ 17,177 $ 1,024 6.34%
High Use/Low Demand 40,000 2,000 $ 14,873 $ 15,417 $ 544 3.66%
Avg.Use/Avg. Demand 30,000 3,000 $ 11,741 $ 12,381 $ 641 5.46%
Low Use/High Demand 20,000 3,000 $ 8,197 $ 8,819 $ 622 7.59%
Low Use/Low Demand 20,000 1,000 $ 7,557 $ 7,939 $ 382 5.06%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 10 of 12

Intermountain Gas Company
Exhibit 38-Bill Impact
Transportation
T-3-TRANSPORT INTERRUPTIBLE
Current Block Current Proposed
Customer Charge $ 300.00 $ 600.00
Demand Charge $ - $ -
Block 1 100,000 $0.03694 $0.03686
Block 2 50,000 $0.01504 $0.01501
Block 3 150,000 $0.00554 $0.00553
Total COG ($0.00205) ($0.00205)
Property Tax $0.00000 $0.00041
Monthly Average Current Monthly Proposed
Usage(Therm) MDFQ(Therm) Bill Monthly Bill Difference$ Difference
- $ 300 $ 600 $ 300 100.00%
100,000 $ 3,789 $ 4,122 $ 333 8.79%
200,000 $ 4,613 $ 4,985 $ 372 8.06%
300,000 $ 4,962 $ 5,374 $ 412 8.30%
400,000 $ 5,311 $ 5,763 $ 452 8.51%
500,000 $ 5,660 $ 6,152 $ 492 8.69%
600,000 $ 6,009 $ 6,541 $ 532 8.85%
700,000 $ 6,358 $ 6,930 $ 572 9.00%
800,000 $ 6,707 $ 7,319 $ 612 9.12%
900,000 $ 7,056 $ 7,708 $ 652 9.24%
1,000,000 $ 7,405 $ 8,097 $ 692 9.35%
1,100,000 $ 7,754 $ 8,486 $ 732 9.44%
1,200,000 $ 8,103 $ 8,875 $ 772 9.53%
1,300,000 $ 8,452 $ 9,264 $ 812 9.61%
1,400,000 $ 8,801 $ 9,653 $ 852 9.68%
1,500,000 $ 9,150 $ 10,042 $ 892 9.75%
1,600,000 $ 9,499 $ 10,431 $ 932 9.81%
1,700,000 $ 9,848 $ 10,820 $ 972 9.87%
1,800,000 $ 10,197 $ 11,209 $ 1,012 9.92%
1,900,000 $ 10,546 $ 11,598 $ 1,052 9.98%
2,000,000 $ 10,895 $ 11,987 $ 1,092 10.02%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 11 of 12

Intermountain Gas Company
Exhibit 38—Bill Impact
Transportation
T-4-TRANSPORT FIRM
Current Block Current Rates Proposed Rates
Customer Charge $ 150.00 $ 300.00
Demand Charge $0.32000 $0.44000
Block 1 250,000 $0.02172 $0.01561
Block 2 500,000 $0.00768 $0.00552
Block 3 750,000 $0.00236 $0.00169
Other Temps(applied to Demand) ($0.05586) ($0.05586)
Property Tax $0.00000 $0.00041
Customer Usage Scenario Monthly Average MDFQ Current Monthly Proposed Difference$ Difference
Bill Monthly Bill
High Use/High Demand 1,000,000 150,000 $ 49,631 $ 65,416 $ 15,785 31.80%
High Use/Low Demand 1,000,000 50,000 $ 23,217 $ 27,002 $ 3,785 16.30%
Avg.Use/Avg.Demand 300,000 30,000 $ 13,888 $ 16,126 $ 2,238 16.11%
Low Use/High Demand 50,000 7,500 $ 3,217 $ 3,982 $ 765 23.78%
Low Use/Low Demand 50,000 2,500 $ 1,896 $ 2,061 $ 165 8.70%
Case No.INT-G-25-02
R.Amen,IGC
Exhibit No. 38
Page 12 of 12