I202608 NOPV Response

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD-P.O.BOX 7608• BOISE,IDAHO 83707•[phone]• FAX:[phone]
July 1,2026
Mr.Jeff Brooks,Programs Manager
Idaho Public Utility Commission
PO Box 83720
Boise,ID 83720-0074
Subject:Response to the Notice of Probable Violation dated June 2,2026(Report#1202608)
Dear Mr.Brooks,
This letter is intended to address one(1)notice of probable violation stemming from a field audit conducted by the
Idaho Public Utilities Commission(IPUC)May 26-27,2026,of Intermountain Gas Company's(IGC)Nampa
District pursuant to Chapter 601 Title,49 United States Code.
PROBABLE VIOLATION
1. 49 CFR 8 192.605 Procedural Manual for Operations. Maintenance. and Emergencies
General. Each operator shall prepare and follow for each pipeline,a manual of written procedures for
conducting operations and maintenance activities and for emergency response.For transmission lines,
the manual must also include procedures for handling abnormal operations.This manual must be
reviewed and updated by the operator at intervals not exceeding 15 months,but at least once each
calendar year.This manual must be prepared before operations of a pipeline system commence.
Appropriate parts of the manual must be kept at locations where operations and maintenance activities
are conducted.
OPS 500 Regulator inspection and Maintenance
4. REGULATOR INSPECTION AND MAINTENANCE
4.1.Regulators shall be set to lockup at the designated lockup pressure, with some allowance for lockup
fluctuation,but the regulator shall lockup at a pressure equal to or less than MAOP.
2. 49 CFR 8 192,703 General
(a) No person may operate a segment of pipeline,unless it is maintained in accordance with this
subpart.
3. 49 CFR 8 191-739 Pressure limiting and regulating stations: inspection and testing.
(a)Each pressure limiting station,relief device(except rupture discs),and pressure regulating station
and its equipment must be subjected to intervals not exceeding 15 months,but at least once each
calendar year,to inspections and tests to determine that it is-
(1) In good mechanical condition.
(2) Adequate from the standpoint of capacity and reliability for the service in which it is
employed.
(3) Except as provided in paragraph(b)of this section,set to control or relive at the correct
pressure consistent with the pressure limits of§ 192.201(a);and
(4) Properly installed and protected from dirt,liquids,or other conditions that might prevent
proper operation.
Finding(s):
Regulator Station 48731-RS-59980 and 48283-RS-59707 primary regulator failed to achieve lock-up. Oil was
preventing lockup at Regulator station 48371-RS-59980 for the third consecutive year during IPUC field audits.
Debris was found in Regulator station 48283-RS-59707 which failed due to heavy debris fouling.

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD-P.O.BOX 7608• BOISE,IDAHO 83707•[phone]• FAX:[phone]
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Debris Fouling Overview 48283-RS-59707 Debris Fouling Closeu 48283-RS-59707
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Overview (oil)48371-RS-59980 Closeu (oil) 48371-RS-59980

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD-P.O.BOX 7608•BOISE,IDAHO 83707•[phone]•FAX:[phone]
intermountain (:as Resnonse
Regulator Station 48283-RS-59707: The regulator was disassembled, cleaned, and reassembled onsite and
subsequently locked up properly.No previous issues have been identified at this location.The primary regulator locked
up as expected during the 2026,2025,2024,2023,and 2022 annual inspections.
Regulator Station 4873 1-RS-59980:As stated in previous response to NOPV I202504,submitted to the IPUC July 31,
2025,
IGC has been in communication with Williams to determine solutions to mitigate the oil. IGC is currently
reviewing and has recentlyproposed to Williams the installation of a coalescent filter at the Nampa Gate.Per
response from Williams, they will perform meter maintenance within the next 3-4 weeks, which will include
the collection and testing of contaminants. Based on the results, Williams will work with manufacturers to
determine the appropriate filter technology for optimum removal of contaminants(e.g., oil).
Until a mitigation plan is developed and implemented,IGC will increase the inspection frequency from annual
to quarterly at Regulator Station 483 71-RS-59980.
On August 4,2025, IGC received a closure letter from the IPUC accepting the response and corrective actions. On
June 2,2026, IGC provided updates to the IPUC via email. IGC confirmed it is continuing quarterly inspections at
Regulator Station 48371-RS-59980 and actively working with Williams Northwest Pipeline on the installation of the
coalescent filter.
Please contact Josh Sanders at(701)222-7773 with questions or comments.
Respectfully Submitted,
Pat Darras
Vice President, Engineering& Operations Services
Intermountain Gas Company