A202601 NOPV Response

Epv 1
2406 N. Dollar Road
Spokane Valley, WA 99212
Submitted to Jeff Brooks via electronic mail at [e-mail].
May 27, 2026
Mr. Jeff Brooks
Pipeline Safety Program Manager
Idaho Public Utilities Commission
11331 Chinden Blvd., Building 8, Suite 201-A
Boise, ID 83714
Re: IPUC Lewiston District Field Audit Probable Violation Letter—Avista Response
Dear Mr. Brooks:
In your letter of April 27, 2026, you listed Probable Violations discovered during the 2026
Lewiston Field Audit that was conducted April 21-22, 2026. In this letter we have provided a
restatement of the probable violations as noted in your letter, and Avista's response.
Notice of Probable Violation (NOPV) References:
49 CFR §192.605
49 CFR §192.703
49 CFR 192.739(a)(1)
49 CFR 192.739(a)(4)
49 CFR 192.703
Avista Gas Standards Manual Section 5.12.
Description of NOPVs
1. 49 CFR§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. (2) Controlling corrosion in accordance with the operations and maintenance
requirements of Subpart I of this part.

49 CFR � 192.703 General
No person may operate a segment of pipeline, unless it is maintained in accordance with this
subpart.
49 CFR§192.739 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 at 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.
(4) Properly installed and protected from dirt, liquids, or other conditions that might prevent
proper operation.
Avista Gas Standards Manual-Section 5.12 Regulator and Relief Inspection Maintenance
of Overpressure Protection Devices
Overpressure protection devices (including relief valves, monitor regulators, and safety
shutoff valves) shall be inspected and tested once each calendar year.
Overpressure protection devices shall be inspected to ensure the following:
• They are in good mechanical condition.
• They have a vent stack that is not restricted and is positioned away from sources of
ignition. Vent caps and screens shall be checked for obstructions, for proper
operation, and to determine that the screens are intact. Replace or repair any defects.
• They are set to function at the correct pressure by using an accurate test gauge. The
regulator inspection and maintenance record shall be consulted to determine the
relief maximum set point as specified by Gas Engineering. In some cases, the relief
set point may be less than the MAOP due to operating restrictions.
• They are properly installed and protected from dirt, liquids, and other conditions
that might affect proper operation.
• Sensing lines, control lines, filters, restrictors, etc. on relief valves have been
inspected and repaired, as necessary.
Findinds)•
Regulator 414 had dithiazine accumulation and a hair on the worker regulator diaphragm, which
interfered with proper lockup. The monitor regulator also failed to achieve lockup. Technicians
corrected both issues by disassembling the units, cleaning the diaphragms, and replacing the pilot
stems. The worker regulator experienced similar failures in 2021 and 2022.

Avista Response to NOPVs:
Avista continues to address the operational issues resulting from dithiazine accumulation at gate
stations and regulator stations. In addition, the company has a Dithiazine Monitoring and
Surveillance Program (as detailed in a previous response to the IPUC in 2022) and addresses the
topic of dithiazine in the company's DIMP Plan Document.
Although Avista concurs that dithiazine is an ongoing operations challenge, we respectfully
disagree that the dithiazine and other issues observed at Regulator Station 414 rise to the level of
being Probable Violations of federal code or Avista Gas Standards.
At Regulator Station 414 neither the monitor regulator nor the worker regulator initially achieved
"bubble tight" lock up as you noted in your letter. The way this station operates, there is
continual flow and no safety or operational requirement for the worker or monitor regulator to
lock up bubble tight. Additionally, there is telemetry at the site such that any pressure delivery
exceedance over acceptable levels, will be immediately alarmed to the Gas Control Room.
There would, consequently, not be an instance where proper operation is affected to the point of
a safety or operations issue during current operations.
A very similar observation to this occurrence was noted during the Coeur d'Alene District Audit
back in June 2023. Avista received a letter with similar NOPVs. We responded to the IPUC
with similar lines of thinking and the NOPVs were eventually considered"invalid"in your letter
of July 24, 2023. It is Avista's hope that you once again see the logic of this response and
rescind these NOPV citations from the Lewiston Audit as you did in 2023.
Respectfully Submitted,
Ryan Bean, PE
Director,Natural Gas
RB/rkb
Cc: Carie Mourin, Manager, Gas Compliance, and Integrity
Ted Boyle, Manager, Lewiston Gas Operations