20260930Notice_of_Amended_Application_Order_No_37191.pdf

Office of the Secretary
Service Date
September 30,2026
BEFORE THE IDAHO PUBLIC UTILITIES COMMISSION
IN THE MATTER OF AVISTA ) CASE NO. AVU-G-26-03
CORPORATION'S APPLICATION FOR AN )
ORDER APPROVING A CHANGE IN RATES ) NOTICE OF AMENDED
FOR PURCHASED GAS COSTS AND ) APPLICATION
AMORTIZATION OF GAS-RELATED )
DEFERRAL BALANCES ) ORDER NO. 37191
On July 31, 2026, Avista Corporation, doing business as Avista Utilities ("Company"),
applied to the Idaho Public Utilities Commission("Commission")requesting approval of proposed
rates in its Purchased Gas Adjustment ("PGA") filing for natural gas service in Idaho
("Application"), effective November 1, 2026. Application at 1. On August 20, 2026, the
Commission issued a Notice of Application and Notice of Modified Procedure, establishing
written comment deadlines. Order No. 37144.
On September 21, 2026, the Company filed an amended application correcting an input
error in the Company's demand costs calculation ("Amended Application"). The Company also
filed a substitute tariff sheet and amended workpapers with the Amended Application. If the
Amended Application is approved,as filed,an Idaho residential customer' that uses approximately
66 therms per month would see a $1.90 decrease in their monthly bill (i.e., decrease from $58.562
to $56.66). Amended Application at 4.
The Commission now issues this Notice of Amended Application.3
BACKGROUND
The Company's rates include a base-rate component and a gas-related cost (PGA)
component. The base-rate component is intended to cover the Company's fixed costs to serve its
customers.For example,the Company's costs for equipment and facilities to provide service rarely
change. The Company's PGA is a Commission-approved mechanism that adjusts rates up or down
1 The Company referred to the monthly bill for Idaho residential and small commercial customers using 66 therms per
month. Amended Application at 4 (emphasis added). However, because the Company only referred to residential
natural gas customers in the cover letter of its Amended Application,the Commission believes the Company means
to only describe the monthly bill for Idaho residential customers using 66 therms per month.
2 The Commission believes that this monthly bill amount does not include the State of Idaho Usage Tax from the
Company's Schedule 157 and thus may not accurately reflect an Idaho residential customer's monthly bill.
3 This Order does not alter or amend the public comment or Company reply deadlines established in Order No.37144.
NOTICE OF AMENDED APPLICATION
ORDER NO. 37191 1

to reflect actual changes in the Company's costs to buy natural gas from suppliers (compared to
the same cost assumptions embedded in rates), including changes in transportation, storage, and
other related costs.
The PGA consists of two tariffs schedules—Schedule 150 and Schedule 155. Schedule 150
is forward looking and estimates the Company's weighted Average Cost of Gas ("WACOG") for
the upcoming PGA deferral period. Schedule 155 amortizes the prior year's deferral of actual gas
costs compared to the amount collected through rates and collects or returns the difference as a
rebate or surcharge.
NOTICE OF AMENDED APPLICATION
YOU ARE HEREBY NOTIFIED that the Company represents that if the Amended
Application is approved as filed, the annual revenue of the Company will decrease by about $3.0
million or 3.6%.Id. at 1.
YOU ARE FURTHER NOTIFIED that the Company represents that the annual PGA
would: (1) pass through the changes in the estimated cost to purchase natural gas for November
2026 through October 2027; and (2) adjust the amortization rate(s) used to return or collect the
deferred natural gas costs balance.Id. at 2-3.
YOU ARE FURTHER NOTIFIED that the Company represents that the proposed
WACOG rate (Schedule 150) would be a decrease by $0.04529 per therm from the present
WACOG of$0.21148 per therm.Id. at 3. The proposed WACOG is $0.16619 per therm.Id.
YOU ARE FURTHER NOTIFIED that the Company states it expects demand costs for
residential customers to increase by approximately $0.00535 per therm.Id. at 4.
YOU ARE FURTHER NOTIFIED that the Company states that the proposed amortization
rate (Schedule 155) change for Schedule 101 and Schedule III customers would increase by
$0.01113 per therm. Id. The Company also represents that the proposed Schedule 155 rate would
be $0.05165 per therm.Id.
YOU ARE FURTHER NOTIFIED that the Amended Application, proposed substitute
tariff rates, and supporting amended workpapers are available for public inspection during regular
business hours at the Commission's office. The Amended Application, proposed substitute tariff
rates, and supporting amended workpapers are also available on the Commission's website at
www.puc.idaho.gov. Click on the"GAS"icon, select"Open Cases,"and click on the case number
as shown on the front of this document.
NOTICE OF AMENDED APPLICATION
ORDER NO. 37191 2

YOU ARE FURTHER NOTIFIED that all proceedings in this case will be held pursuant
to the Commission's jurisdiction under Title 61 of the Idaho Code, and that all proceedings in this
matter will be conducted pursuant to the Commission's Rules of Procedure, IDAPA 31.01.01.000
et seq.
DONE by Order of the Idaho Public Utilities Commission at Boise, Idaho this 30th day of
September 2026.
G
EDWARD LODGE, PRtAIDENT
J R. HAMMOND JR., COMMISSIONER
DAYN HA IE, COMMISSIONER
ATTEST:
o i a anchez
Commission Secretary
L\Legal\GASW VUG2603_PGA\orders\AVUG2603_ntc_app_amd_kr.docx
NOTICE OF AMENDED APPLICATION
ORDER NO. 37191 3