I201903 NOPV Response

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY �+
555 SOUTH COLE ROAD• P.O.BOX 7608• BOISE,IDAHO 83707•[phone]• FAX:[phone] IR E C F I V E D
11 19 JUN 10 AM 9: 29
June 5,2019
1CA H 0 r 11BLI IC
T F I I° COMMISSION
Mr.Darrin Ulmer
Pipeline Safety,Program Manager
Idaho Public Utilities Commission
P.O. Box 83720-0074
Boise,ID 83720-0074
Subject:Response to April 30,2019 Notice of Probable Violations—Boise District
Dear Mr.Ulmer,
This letter is intended to address the April 30,2019 Notice of Probable Violations identified by Idaho Public Utilities
Commission(IPUC)during the April 8-11,2019 field inspection of Intermountain Gas Company(IGC)equipment in
the Boise District.
PROBABLE VIOLATIONS
1. 49 CFR�192.739(a)(1)Pressure limiting and regulating station: Inspection and testing.
Each pressure limiting station, relief device (except rupture discs), and pressure regulating station and its
equipment must be subject at intervals not exceeding 15 months, but at least once each calendar year, to
inspection and tests to determine that it is(1)In good mechanical condition.
Finding:
During the inspection it was noted that 5 regulator stations on the list were not plumbed for lock-up. Meter
inspector was unable to demonstrate that the regulators were functioning properly and were able to lock-up
when the necessity arrives.
Intermountain Gas Response
The primary run of Regulator Station 40086 is plumbed to test for lock-up.On March 13,2019 during the
Annual Regulator Station Inspection,the primary regulator locked up at 56 psig. The secondary regulator,
set 5 psig lower than the primary,was not flowing gas at the time of inspection;therefore,it was locked-up
at the time of inspection.
While performing the 2018 Annual Regulator Station Inspections,IGC inspected and tested the four other
stations identified as not plumbed for lock-up(40048,40087,40091,and 40092). It is recognized that the
test methods utilized by IGC were not as definitive as a gauge reading. However,the inspection and test
practices utilized did give clear indications that the stations were in good mechanical condition. Therefore,
IGC maintains that we have remained compliant with§192.739(a)(1).
Because of the findings in this inspection,IGC has completed a data review of all regulator stations
inspections from the previous year. From this review it has been determined that 89 regulator stations are
not plumbed for a gauge or other appurtenance to test for lock-up. Subsequently,IGC is conducting an
engineering review of each of the 89 regulator stations to determine the best solution to resolve the issues
pertaining to lock-up testing. The engineering review will include a schedule and plan for the retrofit,
replacement,or abandonment of the 89 regulator stations.IGC anticipates completing this engineering
review by December 31,2019.

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD•P.O.BOX 7608• BOISE,IDAHO 83707•[phone]• FAX:[phone]
2. 4192.739(a)(4)Pressure limiting and regulating station: Inspection and testing.
Pressure limiting and regulating stations: Inspection and testing—reads: Properly installed and protected
from dirt, liquids, or other conditions that might prevent proper operation. Which is also covered in IGC
Procedure 4306 Sec 4.1.1.
Finding:
During the inspection it was noted that regulator stations 40072 (primary), 40085 (primary), 40058
(primary),40049(primary),40032(primary),40098(primary)and 40094(primary)had one of its regulators
fail to lock up at the pre-established set point preventing proper operation.
Intermountain Gas Response
During the 2018 Annual Regulator Station Inspections,the primary regulators at three of the above-mentioned stations
(40085,40049,and 40098)failed to lock up due to debris in the regulator. They were rebuilt on site and subsequently
locked up properly. The primary regulators at the four remaining stations sited (40072, 40058, 40032 and 40094)
locked up as expected during their annual inspection. Additionally, as mentioned in IGC's December 13, 2018
response to IPUC's Letter of Concern,we are currently investigating the application of filtration devises at each IGC
regulator station that failed lock-up two or more times during the three-year period from 2016-2018. This initial data
review is scheduled to be completed by June 28,2019, with a plan of remediation to be completed by December 31,
2019. This plan will include a schedule and possible debris filtration solution.
3. 49 CFR Appendix D of Part 192—Criteria for Cathodic Protection and determination of
measurements.
I. Criteria for cathodic protection—A. Steel... (1)A negative(cathodic)voltage of at least 0.85 volt, with
reference to a saturated copper-copper sulfate half-cell. Determination of this voltage must be made with
the protective current applied, and IA section II and IV of this appendix.
Findings:
During the inspection it was noted that at the following locations CP readings were below the standard:
Casing 42509702 (-0.79),42509703 (-0.79)and Reg Station 40048(-0.53). CP technician was aware and
investigating the cause.
Intermountain Gas Response
The above locations with low CP readings,(42509702,42509703,and 40048)all belong to isolation district 425-097.
Reads for Regulator Station 40048 are taken at 1300 Amity. While performing the annual inspection on March 20,
2019, our Corrosion Control Technician found the pipe-to-soil reads to be below criteria. The Technician began
promptly investigating the cause for these low reads.After a full investigation of the isolation district and concluding
there wasn't sufficient cathodic protection,the technician bonded isolation district 425-097 to isolation district 425-
230 on April 12,2019,remedying the issue 30 days after discovery. Shown below are the reads taken during the 2018
and 2019 annual inspections and after bonding the districts.
ID Location Date P/S Read Description
4250971 Isolation District 425-097(1300 Amity) 4/19/2019 -1.53 V After bonding
3/20/2019 -0.73 V 2019 Annual Inspection
3/26/2018 -1.47 V 1 2018 Annual Inspection
42509703 Casing at Enterprise& Boeing, South Scepter 4/19/2019 -1.53 V After bonding
3/20/2019 -0.81 V 2019 Annual Inspection
3/26/2018 -1.41 V 2018 Annual Inspection

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD•P.O.BOX 7608•BOISE,IDAHO 83707•[phone]• FAX:[phone]
42509702 Casing at Enterprise&Boeing,North Scepter 4/19/2019 -1.53 V After bonding
3/20/2019 -0.81 V 2019 Annual Inspection
3/26/2018 -1.53 V 2018 Annual Inspection
Please contact Josh Sanders at(701)222-7773 with questions or comments.
Respectfully Submitted,
Pat Darras
Vice President,Engineering&Operations Services
Intermountain Gas Company