20260522Staff Comments.pdf

RECEIVED
May 22, 2026
KELSEA E. ROSS IDAHO PUBLIC
DEPUTY ATTORNEY GENERAL UTILITIES COMMISSION
IDAHO PUBLIC UTILITIES COMMISSION
PO BOX 83720
BOISE, IDAHO 83702
[phone]
IDAHO BAR NO. 12050
Attorney for the Commission Staff
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF INTERMOUNTAIN )
GAS COMPANY'S 2025 INTEGRATED ) CASE NO. INT-G-25-08
RESOURCE PLAN )
COMMENTS OF THE
COMMISSION STAFF
COMMISSION STAFF ("STAFF") OF the Idaho Public Utilities Commission
("Commission"), by and through its attorney of record, Kelsea Ross, Deputy Attorney General,
submits the following comments.
BACKGROUND
On December 23, 2025, Intermountain Gas Company ("Company") filed its 2025
Integrated Resource Plan ("2025 IRP") with the Commission and requested that the Commission
issue an order acknowledging the Company's 2025 IRP. The Company's 2025 IRP is
approximately one hundred and sixty-six (166) pages, with approximately five hundred and
fourteen(514)pages of Exhibits. The 2025 IRP sets forth four substantive sections: (1)Executive
Summary; (2)Demand; (3) Supply and Delivery Resources; and(4)Optimization. 2025 IRP at ii-
vi.
The 2025 IRP outlines the Company's projected customer demand over a five-year
planning horizon, the resource strategies expected to meet that demand, and the decision-making
framework used to evaluate resource options. Id. at 1. The Company incorporates public
participation as an element of the 2025 IRP process, and in accordance with regulatory
STAFF COMMENTS 1 MAY 22, 2026

requirements, the Company submits an updated Integrated Resource Plan ("IRP") to the
Commission every two years. Id. The 2025 IRP represents a point-in-time assessment of
anticipated conditions rather than a definitive roadmap for future resource decisions, as market,
regulatory, and operational factors may evolve over the planning period.Id.
The Company's 2025 IRP, evaluates residential, commercial, and large-volume customer
demand growth under multiple scenarios and assesses the resulting impacts on its distribution
system using design-weather conditions. Id. at 5. Forecasted demand is compared with existing
natural gas delivery capabilities to identify the potential magnitude and timing of system
constraints, both system-wide and within each area of interest ("AOI"). Id. The Company also
evaluates a range of resources, solutions, and Energy Efficiency (`BE") measures to identify the
most cost-effective and operationally feasible approaches to addressing these constraints. Id.
Integrated Resource Plan Requirements
In Order No. 25342, the Commission adopted IRP requirements for local gas distribution
companies in response to amended Section 303 of Public Utility Regulatory Policies Act. In Order
No. 25342, local gas distribution companies are required to submit an IRP biannually. In Order
No. 27024, the Commission shortened the IRP planning horizon from 20 years to five years. In
Order No. 27098, the Commission removed the requirement that IRPs formally evaluate potential
demand side management ("DSM") programs and instead directed the companies to explain
whether cost-effective DSM opportunities exist.
In Order No. 32855, the Commission: (1) directed the Company to continue to improve
public participation in its IRP process; and (2) allowed the Company to stop filing semi-annual
lost and unaccounted for gas ("LAUF") reports. The IRP's LAUF section must explain the
Company's: "(a) framework for how it tested, identified,and remediated equipment measurement
errors or leaks; and (b) business process used for alleviating measurement errors through its
financial accounting of nominations, scheduling, measurements, flow volume allocation, and
billing." Order No. 32855. Order No. 25342, Order No. 27024, Order No. 27098, and Order No.
32855 are collectively referred to herein as "Orders."
In summary, these Orders direct the Company to include in its IRP:
STAFF COMMENTS 2 MAY 22, 2026

1. A forecast of future gas demand in firm and interruptible markets for each customer
class, including the number,type,and efficiency of gas end-users, as well as the effects
of economic forces on gas consumption;
2. An analysis of gas supply options for each customer class, including a projection of
spot market versus long-term purchases for both firm and interruptible markets; an
evaluation of opportunities for using company-owned or contracted storage or
production; an analysis of prospects for company participation in a gas futures market;
and an assessment of opportunities for access to multiple pipeline suppliers or direct
purchases from producers;
3. A comparative analysis of gas purchasing options and improvements in the efficient
use of gas, and an explanation of whether there are cost-effective DSM opportunities;
4. The integration of the demand forecast and resource evaluations into a long-range (at
least a five-year) plan describing the strategies designed to meet current and future
needs at the lowest cost to the utility and its ratepayers;
5. A short-term(e.g.,two-year)plan outlining the specific actions to be taken by the utility
in implementing the IRP;
6. A progress report that compares the new plan to the previously filed plan; and
7. A description of how the Company will continue to facilitate public participation.
STAFF ANALYSIS
Staff examined the Company's 2025 IRP to determine whether it satisfies Commission
requirements and Orders and adequately plans for the capability to meet demand from 2025
through 2030. Staff believes that the 2025 IRP satisfies Commission requirements and is
reasonable. Accordingly, Staff recommends the Commission acknowledge the 2025 IRP.
Demand Forecast
The Company's demand forecast is used to determine the timing and capacity of new plant
additions.Id. at 10. The demand forecast is an important driver of expenditures that will eventually
be included in the Company's rates. Staff reviewed the Company's methodology for estimating
future demand and believes it was adequate.
STAFF COMMENTS 3 MAY 22, 2026

The Company's demand forecast is based on three components: (1) a prediction of the
number of customers; (2) a forecast of the amount of gas customers will use; and (3) an estimate
of the weather conditions customers may experience. 2025 IRP at 10. The Company also includes
contracted maximum deliveries to industrial customers in its demand forecast. Id.
The Company forecasted changes in its peak-day loads due to customer growth under its
low growth, base case, and high and low growth economic scenarios. Id. at 2. The Company
forecasted total system peak-day loads to grow at a compound annual growth rate of 1.12% (low
growth), 1.46% (base case), and 1.86% (high growth). Id. at 112.
The Company identified deficits on both a total system perspective and within its AOIs.
Id. at 5. For each potential deficit, the timing and magnitude were identified. Id. The Company
evaluated and compared potential capacity improvement alternatives for each identified capacity
deficit in its optimization model. Id. at 95. The Company calculated and compared the net present
value cost,the amount of capacity, and the capacity gain for each potential capacity improvement,
which are described in greater detail in the Deficits and AOI Summaries section below.
Deficits and AOI Summaries
The Company analyzed five AOIs over the 2025-2030 IRP planning period: (1) Canyon
County; (2) State Street Lateral; (3)Central Ada County; (4) Sun Valley Lateral; and(5)the Idaho
Falls Lateral. Id. at 95. The Company projects deficits in its State Street Lateral and the Idaho
Falls Lateral. Id. at 95106. The Company provided a capacity analysis, identified when deficits
will occur, and described enhancements to resolve identified deficits. Staff reviewed the
Company's method for determining the design day, and the resulting peak-delivery requirements
under various growth assumptions and believes the Company's analysis is reasonable. Staff
encourages the Company to continue to provide Staff with capacity and cost information through
annual updates during non-filing years as enhancement projects are completed and brought online.
A summary of the capacity enhancements selected for each AOI with an identified deficit
and Staff s specific conclusions are provided below.
State Street Lateral. The State Street Lateral,located in southwest Idaho,serves primarily
residential and commercial customers in the Star, Eagle,Meridian, and northwest Boise areas. Id.
at 97. In the 2021 IRP, the Company considered two capacity enhancement alternatives and
STAFF COMMENTS 4 MAY 22, 2026

selected the "State Street Phase II Uprate"as the lowest cost alternative. Id. at 98. The Company
stated that it budgeted the State Street Phase II Uprate for 2026 at an estimated cost of$1,200,000.
Id. Staff accepts the Company's cost assertion. However, the Company did not describe the
estimated costs for the other capacity enhancement alternative. For future IRPs, Staff requests that
the Company present each capacity enhancement alternative with updated costs to confirm that the
preferred alternative selected by the Company is still the lowest cost option.
Idaho Falls Lateral. The Idaho Falls Lateral ("IFL"), located in eastern Idaho, serves
cities between Pocatello on the south and to St. Anthony on the north. Id. at 100. The IFL utilizes
a Liquefied Natural Gas ("LNG") facility located in Rexburg to supplement the lateral's capacity
during a peak demand day. Id. at 50. The Company transports LNG to the Rexburg facility from
its Nampa, Idaho LNG facility. Id. The IFL AOI requires capacity enhancements by 2026 and
2030. Id. at 99.
The Company considered two capacity enhancement alternatives in the 2021 and 2023
IRPs to address the 2026 deficit. Id. at 100. The Blackfoot Compressor Station alternative was
chosen in both IRPs as the least-cost option per therm/day of capacity gained. Id. The Company
expects the Blackfoot Compressor Station to be completed in 2026, estimates that it will cost
$32,520,992, and states that the project will satisfy predicted growth through 2029. Id. at 101.
Staff appreciates the Company's update on this ongoing project and encourages the Company to
document the final cost and in-service date at the Company's annual update meeting or in its next
IRP.
To address the identified deficit in 2030, the Company considered two capacity
enhancement alternatives, including a separate compressor or pipeline loop upstream of the
Blackfoot Compressor Station. Id. at 102. The Company represented it is currently considering
the pipeline loop due to it being the lower cost alternative at an estimated cost of$42,000,000. Id.
at 103. Staff recommends continued evaluation of the pipeline loop enhancement in the next IRP.
Other Upgrades/Enhancements. The Company describes two gate upgrades that fall
outside of the above AOIs. Id. at 104. The Company states that upgrades are needed in 2027 at
the New Plymouth gate and the State Penn gate to support growth. Id. The New Plymouth gate
STAFF COMMENTS 5 MAY 22, 2026

upgrade is estimated to cost $3,640,000, and the State Penn gate upgrade is estimated to cost
$2,980,000. Id. at 105.
In addition to the two gate upgrades, the Company describes a significant distribution
reinforcement located in Caldwell along Highway 20. Id. at 104. The reinforcement involves
looping the Company's distribution system to bring gas to the area at reduced construction cost
due to several large developments planned for the area and the widening of the highway. Id. The
Caldwell reinforcement is scheduled to be completed in 2027 based on the Idaho Transportation
Department's construction schedule and is estimated to cost $3,650,000. Id. at 105.
For all three of these projects,the Company has stated there are no alternatives. Id. at 104.
Staff accepts the Company's explanation but plans to ask the Company for evidence that the
physical capacity limits have been reached when the Company requests a determination of
prudence for the two gate projects in a future filing. Staff encourages the Company to document
the final cost and in-service dates for each project at the annual update meeting or in the next IRP.
Supply Options
The Company's service territory is located between the Western Canadian Sedimentary
Basin ("WCSB") located in Alberta and British Columbia and in the Rockies region located in
Wyoming, Colorado, and Utah. Id. at 40. A bi-directional interstate pipeline operated by
Northwest Pipeline runs through the Company's territory and enables purchases from both regions.
The WCSB supplies approximately 79% of the Company's natural gas. Id.
The Company utilizes natural gas storage as a capacity resource. Id. at 50. Currently, the
Company has storage capacity in four facilities. Id. Two of the facilities, one at Jackson Prairie
and the other at Plymouth, Washington, are operated by Northwest Pipeline. Id. A third facility,
the Dominion Energy storage field (Clay Basin), is located near the Utah and Wyoming border.
Id. The fourth storage facility, the Company-owned LNG facility, located in Nampa, Idaho, is
described in greater detail below. Id.
Nampa LNG Facility
The Nampa LNG plant is primarily used to supplement gas supply to the Company's
distribution system. Id. at 54. The plant is capable of storing up to 600 million cubic feet of LNG.
STAFF COMMENTS 6 MAY 22, 2026

Id. The plant can re-gasify approximately 50 million cubic feet per day and inject the gas into the
Company's Canyon County and Ada County distribution systems when needed. Id. at 54.
During off-peak months,the Nampa LNG facility obtains pressurized natural gas from the
Canyon County lateral, liquefies it, and then stores it in a large steel storage tank with a capacity
equivalent to 600 million standard cubic feet of gas (about 600,000 Dth).Id. at 53. The liquified
gas is withdrawn to supply the Company's non-utility customers, and during winter months,LNG
is trucked from the Nampa LNG facility to the Company's satellite LNG facility in Rexburg, ID.
Natural gas liquefication is an energy intensive process, and using LNG to meet demand for
purposes beyond needle peaking events can be costly. However, gas trucked from the Nampa
facility to the Company's facilities in Rexburg, ID is central to meeting the Idaho Falls Lateral's
needle peak demand.Id. at 65.
Purchasing Options
As part of the 2025 IRP, the Company creates a base, high, and low natural gas price
forecast based on pricing forecasts sourced from Wood Mackenzie, the U.S. Energy Information
Administration("EIA"), S& P Global,New York Mercantile Exchange ("NYMEX")Henry Hub,
and the Northwest Power and Conservation Council. Id. at 49. The Company states that it utilizes
a proprietary model to select a monthly base price projection for purchase points for the AECO,
Rockies, and Sumas markets. Id. The forecasts for these markets are shown in Chart 1 below. Id.
at 50. The Company uses this type of analysis,along with input from its Gas Oversight Committee,
to hedge a portion of its gas supply portfolio at fixed price forward physicals. Id. at 49.
STAFF COMMENTS 7 MAY 22, 2026

Chart 1 - Company Natural Gas Price Forecast
• IGC Natural Gas Price Forecast (as of 5-7-2025)
Ss.(k)
57.00
56.00
OP
55.00
m
54.00
$3.00 -
52.
51.00 -
OP
so.00
lac �aJ ljl lac J 44 lac J .40 1;§ J 4 411
Suma�s& Rockies AECO Weighted
Figure 26:Intennountain Price Forecast as of 0510712025
Id. at 50.
Enemy Efficiency
The Company's IRP considers energy efficiency (`BE")programs that can offset demand.
Id. at 39. The goal of EE programs is to acquire a cost-effective demand side resource that
displaces the need to purchase additional gas supplies, delay contracting incremental pipeline
capacity, and possibly delay or defer distribution system reinforcements. Id. at 73. The 2025 IRP
estimates therm savings potential using a Conservation Potential Assessment ("CPA"). Id. Staff
reviewed the Company's 2023 CPA, its impact on the 2025 IRP, and its plans for future CPA
studies. Staff s concerns are addressed below.
Conservation Potential Assessment
For its 2025 IRP the Company did not conduct a standalone 2025 CPA. Id. at 73. Instead,
the Company contracted with Guidehouse("Evaluator")to update several global inputs within the
2023 CPA model, which was then used for the 2025 IRP ("Updated 2023 CPA"). Id. The
Evaluator updated building stock, sales, avoided costs, inflation rates, and discount rates, as well
STAFF COMMENTS 8 MAY 22, 2026

as extended the forecast period by two years. Id. at 74. While this allowed the Company to obtain
an updated EE savings potential forecast for the 2025 IRP at a significantly reduced cost, Staff is
concerned that the model results inherit issues from the calibration from the 2023 CPA and that
the unit energy savings ("UES")inputs sourced from the commercial Residential and Commercial
Technical Reference Manuals("TRMs")are unreasonably high. Staff believes that the Company's
forecasted energy savings potential is overstated and cautions against using the results of the
Updated 2023 CPA to plan any EE program changes.
Model Calibration
Staff has ongoing concerns with the data used for model calibration of the Company's 2023
CPA which was used in the 2025 IRP. In its comments on the Company's 2023 IRP in Case No.
INT-G-23-07, Staff expressed concern that the Company used overstated savings estimates to
calibrate its models, which in turn led to overstated forecasts for energy savings potential. Staff
Comments for Case No. INT-G-23-07 at 10. In its response to Staff Production Request No. 15
in this case,the Company stated that the Updated 2023 CPA model results were not re-calibrated.
Staff believes that previous concerns over using overstated savings estimates for the purpose of
calibration have not been addressed, thus the residential sector saving estimates are still inflated.
Commercial Savings Estimates
The Company stated in its response to Staff Production Request No. 2 that the Evaluator
updated the 2023 CPA UES model inputs using the TRM. In its comments in Case No. INT-G-
25-07, Staff disagreed with the commercial TRM savings estimates. Staff Comments in Case No.
INT-G-25-07 at 13. On May 5, 2026, the Commission issued Order No. 37033 denying the
Company's application for its proposed commercial program changes and directed the Company
to work with Staff to discuss changes to the commercial TRM. Based on the analysis conducted
by Staff in the filing for Case No. INT-G-25-07, Staff believes the Evaluator included overstated
commercial sector UES inputs in its CPA, which caused the savings potential to also be
overestimated.
STAFF COMMENTS 9 MAY 22, 2026

Impacts on IRP and Program Planning
Due to Staff s concerns with the Updated 2023 CPA, Staff believes the impact of the
forecasted savings potential on the rest of the 2025 IRP is unclear. Staff believes the Company's
forecasted achievable savings potential is significant when compared to the projected load growth
in the base case, design weather 2025 IRP scenario. The Updated 2023 CPA model estimates
about 6.1 million therms in achievable savings potential between 2026 and 2030. Id. at 79. This
is about 11% of the projected 54 million therms of growth in usage. Id. at 111. However, Staff is
concerned that overstated savings forecasts will likely result in an overestimated demand
reduction. This could obfuscate capacity deficits and reinforcement option selections needed on
the system. Additionally, in the meeting with Staff and its CPA consultant regarding issues with
the Company's CPA in Case No.INT-G-23-07(that the Commission directed in Order No.36249),
the Company stated that its EE forecasts did not defer any capital projects for the 2025 IRP
reducing Staffs concerns that an overstated value may be covering a capacity deficit.
Even with more reasonable modeling, Staff believes that the impact of the forecasted EE
savings on the 2025 IRP would be unclear. The EE savings potential is used as an input to the
PLEXOS Optimization Model. Id. at 107 and 132. The resulting Load Demand Curve ("LDC")
guides long-term planning and highlights potential capacity constraints. Id. at 107. This process
produces LDCs that reflect the impacts of potential EE strategies. 2025 IRP at 132. However,
Staff believes it is not possible to evaluate the effects of EE forecasts on the Company's anticipated
capacity deficits and reinforcement option selections without a non-EE baseline to compare the
LDC forecast against. For this reason, Staff recommends the Company consider including a
forecast produced by the PLEXOS model under a scenario where no EE savings were forecasted
and a comparison of this result with its EE inclusive forecast in the Company's 2027 IRP.
Next CPA
In its April 2026 Energy Efficiency Stakeholder Committee ("EESC"), the Company
described its plans for its 2027 CPA. In its response to Staff Production Request No. 3 for Case
No. INT-G-26-02, the Company explained that it intends to contract with a third-party consultant
to conduct a Furnace Evaluation, Measurement, and Verification Study ("EM&V") that separates
savings for new construction,retrofit,and replacement,in compliance with Order No. 36797. Case
No. INT-G-26-02, Company's Response to Production Request No. 1 —Confidential Attachment
STAFF COMMENTS 10 MAY 22, 2026

"2026 UCT Residential Forecast." The Company represented the results, along with updated
savings estimates for other measures,will be used to complete a full-scale CPA study for the 2027
IRP and to develop program design for cost-effective EE programs. Case No. INT-G-26-02,
Company Response to Staff Production Request No. 3.
Staff believes that using up-to-date and accurate savings estimates in the CPA model is
critical in analyzing the potential of EE programs. The results should be reliable enough to be
used to identify potential cost-effective measures and serve as a foundation for program planning.
Staff has consistently stated concerns over the Company's use of overstated and/or outdated
savings values to estimate achievable EE savings potential. Staff Comments for Case No. INT-G-
21-06 at 9; Staff Comments for Case No. INT-G-23-07 at 10. In a telephone call with Staff the
Company represented to Staff that it plans to improve the accuracy and usefulness of the 2027
CPA; however, Staff believes the Company should use the most up-to-date savings estimates,
including those produced by its upcoming Furnace EM&V, to build and calibrate the 2027 CPA
model.
The Company represented in its April 2026 EESC presentation that it intends to review all
study results with the EESC and the Intermountain Gas Resource Advisory Committee
("IGRAC"). However, Staff believes the results of the CPA and program design are ultimately
the responsibility of the Company. Staff recommends that the Company thoroughly review any
third-party evaluation results and planning elements before filing proposed program changes in a
future Commission docket.
EE Avoided Cost
The 2025 IRP describes the three major components of the EE avoided costs as the
commodity cost, transportation cost, and variable distribution cost. Id. at 83. The commodity
costs represents the purchase price of natural gas. Id. In the 2025 IRP, the Company forecasted
the commodity cost of gas using a weighted average price from the Company's three primary
supply basins and adjusting the prices by the Heating Degree Days ("HDD") of each month. Id.
The transportation costs are the costs incurred by the Company for the delivery of gas to its
distribution system. Id. The Company's per therm transportation cost is calculated as the weighted
average of gas transportation costs from the Company's residential and commercial tariffs and
increased each year by the model's inflation rate, which was 3.99% in the 2025 IRP. Id. The
STAFF COMMENTS 11 MAY 22, 2026

Company updates the transportation costs each year to reflect the most recent Purchased Gas Cost
Adjustment ("PGA") filing. Id. The variable distribution costs are the cost associated with
deferred or delayed capacity expansion projects. Id. In the 2025 IRP,the distribution cost remains
at zero while the Company and its stakeholders investigate methods to quantify these savings. Id.
Staff believes the Company's avoided cost calculation and the support for its components
are consistent with discussions from the EESC avoided cost subcommittee. Staff believes that the
Company's 2025 EE avoided costs and supporting methodologies are reasonable.
In its April 2026 EESC, the Company described its plan to reconvene its avoided cost
subcommittee, in which Staff intends to participate. Similar to the previous iteration of this
subcommittee,if the Company identifies any potential changes, Staff anticipates that the Company
will file any proposed changes to its avoided cost practices with the Commission for approval.
Renewable Natural Gas
Renewable Natural Gas ("RNG") is pipeline-quality gas that utilizes biomass materials
to produce a renewable fuel gas, and when purified is fully interchangeable with conventional
natural gas. U.S. Department of Energy,Alternative Fuels Data Center,
hgps://afdc.energy.gov/fuels/natural gas_renewable.html(last visited May 13, 2026).
The Company is involved in the growth and development of the RNG industry in Idaho.
In 2020, the Company filed an application with the Commission seeking authority to facilitate
RNG access. Application in Case No. INT-G-20-03. In Order No. 34693, issued in Case No.
INT-G-20-03, the Commission approved the Company's RNG facilitation plan. The Company's
RNG facilitation agreement allows RNG producers to access the Company's distribution system
to transport RNG to their end-use customers. 2025 IRP at 8. Currently, the Company reports
multiple RNG producers located in Idaho supplying RNG from landfill and dairy operations and
expects additional RNG producers to interconnect to its system. Id. at 66.
1 Biomass is any biodegradable organic material that can be derived from plants, animals,animal byproduct,
wastewater,food/production byproduct and municipal solid waste.
STAFF COMMENTS 12 MAY 22, 2026

Five-Year Plan
One of the requirements of a natural gas IRP under the Orders is for the Company to include
the integration of the demand forecast and resource evaluations into a long-range (at least a five-
year)plan describing the strategies designed to meet current and future needs at the lowest cost to
the utility and its ratepayers. The Company provided the following table to summarize its five-
year plan. Id. at 106.
A01--I Ada County State Street Lateral Canyon County Wr Idaho Falls Lateral
_7�_d . Capacity Capacity Capacity 14pacity Capacity
Year Capacity Capacity Capacity city Capacity
�J.ct ed Selected Selected Ito -elected Selected
Enhancement Enhancement Enhancement mhancement Enhancement
Wapello
State Street Compressor
2026 1 870,000 None 950,000 Uprate 1,390,000 None 247, 000 None 1,037,000 Station
2027 870,000 None 950,000 None 1,390,000 None 247,500 None 1,037,000 None
2028 870,000 None 950,000 None 1,390,000 None 247,500 None 1,037,000 None
2029 870,000 None 950,000 None 1,390,000 None 247,500 None 1,037,000 None
IFL Compressor
Suction
2030 870,000 None 950,000 None 1,390,000 None 247,500 None 1,122,000 Reinforcement
Table 10:A01 Capacity Summary and Timing
The Company will continue to review its five-year plan,identified deficits,and alternatives
considered for capacity enhancement in the development of the 2027 IRP. Id. The Company will
modify its plan as needed to meet demand predictions and ensure safe, reliable service to its
customers. Id.
Short Term Plan
One of the requirements of a natural gas IRP under the Orders is for the Company to
provide a short-term(e.g.,two-year)plan outlining the specific actions to be taken by the utility in
implementing the IRP. Attachment A supplied by the Company to Staff and attached hereto,
identifies the primary focus points of EE, upstream capacity and supply, and distribution system
infrastructure. The Company's two enhancements identified within the next two years are the
State Street Uprate Project and the Wapallo Compressor Upgrades. Attachment A.
Progress Since the Previous IRP
In Order No. 36249, Case No. INT-G-23-07, the Commission stated:
The Commission appreciates the work done by the Company and by Staff
to ensure that the IRP and the IRP process continues to be informed by the
STAFF COMMENTS 13 MAY 22, 2026

most accurate and relevant resource information. The Commission believes
that communication between the parties is one of the keys to that end;
therefore, the Company is directed to work with Staff to implement IRP
reporting that includes system enhancement information in future IRPs, as
well as to develop reports to the Commission of capacity enhancement
projects that include in-service dates and project costs. Staff is also directed
to meet with the Company and its CPA consultant to discuss any issues
related to the current CPA.
Order No. 36329.
To address system enhancements, the Company provided an outline of the criteria and a
description of the process used to address an identified deficit. 2025 IRP at 90. Several examples
are provided, including the criteria considered for each of these mitigation examples. Id. The
Company also provided its selection guidelines and approval processes for distribution system
enhancements. Id. at 92.
For each AOI, the Company provided a summary and description of system dynamics, as
well as identified known capacity limitations and the selected enhancement for any projected
capacity deficit. Id. at 96-105. While much of the information requested in Order No. 36249 is
provided in the 2025 IRP, projected or known in-services dates and project costs were not
consistently provided.
Staff encourages the Company to document the final cost and in-service dates for each
project at the annual update meeting or in the next IRP.
Public Participation
In Order No. 33997, Case No. INT-G-17-04, the Commission directed the Company to
convene an IRP advisory group and work with it to develop future IRPs that comprehensively and
transparently consider demand, existing resources, and potential supply and demand-side options
for meeting any deficits. Id. at 8.
The Company established the IGRAC. 2025 IRP at 4. The intent of IGRAC is to provide
a forum through which public participation can occur as the IRP is developed. Id. Advisory
committee members were solicited from across the Company's service territory to represent the
communities served by the Company. Id.
The Company states that it held four IGRAC meetings in 2025 on a virtual platform. Id.
The Company states that it provided a comment period after each meeting to ensure feedback was
timely and could be incorporated into its IRP. Id. Staff attended each of the meetings. Staff
STAFF COMMENTS 14 MAY 22, 2026

recognizes the Company's efforts to enhance public participation, appreciates the opportunity to
participate in the IGRAC, and looks forward to the Company's continued public involvement in
the development of future IRPs.
Lost and Unaccounted for Gas
The 2025 IRP reports its LAUF rate of 1.1% for the period of July 2024 to June 2025. Id.
at 68. Staff compared the LAUF reported in Response to Staff Production Request No. 5 to the
LAUF totals reported to the Pipeline and Hazardous Materials Safety Administration("PHMSA")
on Form PHMSA F 7100,1-1 (rev 6-2023) and identified a significant discrepancy.
Staff requested the LAUF calculation method used by the Company and determined that
the Company has been using a calculation method that is not consistent with the method prescribed
by PHMSA. Response to Staff Production Request No. 7. In its supplemental response to Staff
Production Request No. 7, the Company indicated that it will conform to the PHMSA-prescribed
formula for all future reporting beginning in 2026.
Staff believes the Company's alternative calculation method provided inaccurate amounts
of LAUF reported for the last several years. Thus, Staff recommends the Commission direct the
Company to use the PHMSA-prescribed formula for all LAUF calculations going forward.
STAFF RECOMMENDATION
Staff believes the 2025 IRP analyzed residential, commercial, and industrial customer
growth and its impact on the Company's system under multiple scenarios. Staff believes the
Company's 2025 IRP meets the Commission's IRP requirements. Staff recommends that the
Commission:
1. Acknowledge the Company's 2025 IRP; and
2. Direct the Company to use the PHMSA-prescribed formula for all LAUF
calculations going forward.
STAFF COMMENTS 15 MAY 22, 2026

Respectfully submitted this 22nd day of May 2026.
/s/Kelsea E. Ross
Kelsea E. Ross
Deputy Attorney General
Technical Staff. Michael Eldred, Vicki Stephens, Rebecca Cottrell
I:\Utility\UMISC\COMMENTS\INT-G-25-08 Comments.docx
STAFF COMMENTS 16 MAY 22, 2026

Attachment A
Here is a summary of the two-year action plan:
Energy Efficiency
Intermountain will continue to acquire all cost-effective, projected energy efficiency savings
identified in this IRP.This includes ongoing implementation of customer efficiency programs and
evaluation of additional opportunities as market conditions,technologies, and customer
participation evolve.
Upstream Capacity and Supply
Intermountain plans to participate in the Rockies Express Pipeline expansion to the extent
participation remains cost-effective and consistent with projected system needs.This participation
is intended to enhance supply diversity, system flexibility, and reliability during peak demand
periods.
Distribution System Infrastructure
To support projected load growth and maintain system reliability, Intermountain expects to advance
the following distribution system projects in the near term:
• State Street Uprate Project,to address localized capacity constraints and improve delivery
capability.
• Wapallo Compressor Upgrades,to enhance compression capacity and operational
flexibility under peak conditions.
These projects are consistent with the IRP's preferred strategy and are expected to be evaluated,
refined, and implemented through normal engineering, budgeting, and regulatory processes.
Received from Michael Parvinen via e-mail 5/4/2026
ATTACHMENT A
Case No. INT-G-25-08
Staff Comments
May 22,2026

CERTIFICATE OF SERVICE
I HEREBY CERTIFY THAT I HAVE THIS 22nd DAY OF MAY 2026, SERVED
THE FOREGOING COMMENTS OF THE COMMISSION STAFF , IN CASE NO.
INT-G-25-08, BY E-MAILING A COPY THEREOF, TO THE FOLLOWING:
MICHAEL PARVINEN PRESTON N. CARTER
DIR—REGULATORY AFFAIRS GIVENS PURSLEY LLP
INTERMOUNTAIN GAS CO 601 W BANNOCK ST
PO BOX 7608 BOISE ID 83702
BOISE ID 83707 E-MAIL: prestoncarter(&givenspursley.com
E-MAIL: michael.parvinen(a),cn cg com [e-mail]
igcre ug latogAint a
PATRICIA JORDAN, ECRETARY
CERTIFICATE OF SERVICE