I201909 NOPV Response

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD•P.O.BOX 7608•BOISE,IDAHO 83707•[phone]• FAX:[phone] RECEIVED
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August 15,2019
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Mr. Darrin Ulmer
Pipeline Safety,Program Manager
Idaho Public Utilities Commission
P.O. Box 83720-0074
Boise,ID 83720-0074
Subject:Response to July 15,2019 Notice of Probable Violations—Pocatello District
Dear Mr.Ulmer,
This letter is intended to address the July 15, 2019 Notice of Probable Violations identified by Idaho Public Utilities
Commission(IPUC)during the July 8-10,2019 field inspection of Intermountain Gas Company(IGC)equipment in
the Pocatello District.
PROBABLE VIOLATIONS
1. 49 CFR 4192.739(a)(1 &3)Pressure limiting and regulating station: Inspection and testing.
Pressure limiting and regulating stations: Inspection and testing—reads: 1.)In good mechanical condition.
3.)Except as provided in... set to control or relieve at the correct pressure consistent with the pressure limits
of 19.201(a).
Finding:
During the inspection it was noted that: regulator station 60076 had tubing leaks on both pilot inlets and
regulator station 60118 had one or both regulators fail to lock up at the pre-established set point preventing
proper operation.
Intermountain Gas Response
IGC maintains the leaks on the threaded connections at District Regulator Station 60076 are not a violation
of§192.739(a) (1). The grade 2 leak identified during the IPUC inspection was repaired at the time of
discovery which exceeds the requirements of standard operating procedure 4204—Leak Surveys.
As mentioned in IGCs December 13,2018 response to the November 16,2018 Letter of Concern and IGCs
June 5,2019 response to the April 30,2019 Notice of Probable Violations,IGC is 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.Because District Regulator Station 60118 was installed on September
7,2016 and the first indication of sulfur was March 15, 2018 during the annual inspection, 60118 was not
identified on the initial data review. 60118 will now be included in the investigation for the application of
filtration devices.
2. 49 CFR 4 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 sections II and IV of this appendix.
Findin s•

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD•P.O.BOX 7608•BOISE,IDAHO 83707•[phone]•FAX:[phone]
During the inspection it was noted that at the following locations had CP readings that were below the
requirement of-0.85: Regulator Stations 60067 and 60068(-0.81 on both regulators).CP technician stated
that he would be placing anodes in the area to elevate the low readings.
Intermountain Gas Response
The buried steel piping of regulator stations 60067 and 60068 are part of Isolation District 679-062 which had a pipe
to soil read of-1.05 volts at Test Point ID 67906210 when the annual read was taken by the Corrosion Technician on
April 5, 2019. After installing anodes at the inlets of regulator stations 60067 and 60068 and turning up Rectifier
R03062679 on July 10,2019,the pipe to soil read at regulator stations 60067 and 60068 is-0.86 volt. Because of the
acceptable readings during the annual inspection,and when deficiencies were found IGC took prompt remedial action
as required by§192.465(d),we maintain the CP readings that were below the Appendix D to Part 192 requirement of
-.85 volt are not a violation.
Please contact Josh Sanders at(701)222-7773 with questions or comments.
Respectfully Submitted,
Pat Darras
Vice President,Engineering&Operations Services
Intermountain Gas Company