I201805 NOPV Response

EXECUTIVE OFFICES
INTERMOUNTAIN GAS COMPANY
555 SOUTH COLE ROAD• P.O.BOX 7608• BOISE,IDAHO 83707• 208 377-6000• FAX:[phone] r r
5 �' +J
December 21,2018
Mr.Joe Leckie
Executive Director
Idaho Public Utilities Commission
P.O.Box 83720-0074
Boise,ID 83720-0074
Subject:Response to November 16,2018 Notice of Probable Violations—Owyhee District
Dear Mr. Leckie,
This letter is intended to address the November 16,2018 Notice of Probable Violations identified by the Idaho Public
Utilities Commission during the August 21-23,2018 Nampa#2 Field Inspection of Intermountain Gas Company's(IGC)
equipment in the Owyhee District.
PROBABLE VIOLATIONS
1. 49 CFR 4192.323(d)Casing.
Each casing used on a transmission line or main under a railroad or highway must comply with the following:
If vents are installed on a casing,the vents must be protected from the weather to prevent water from entering
the casing.
Finding:
During the inspection it was noted that one vent(#267-01-315)was completely buried and three others were
within a few inches of being in the same condition. The concern is during inclement weather either snow
would cover vent or water intrusion.
Intermountain Gas Response
On August 31,2018,IGC raised the vent stacks for casings 26701315,26701306,2671305,and 26701309.
(See Figure i, Figure 2, Figure 3, Figure 4,and Figure 5 respectively.)
2. 49 CFR 092.707(a)(1)Line markers for mains and transmission lines.
...a line marker must be placed and maintained as close as practical over each buried main and transmission
line: At each crossing of a public road and railroad;and...
Finding:
During the inspection it was noted that along Columbia driving to reg station 40107 there were no visual line
markers. On one end a carsonite was found flat on the ground,but on the other end there were no markers.
Intermountain Gas Response
IGC added Carsonite pipeline markers along Columbia Road near Regulator Station 40107 as requested. (See Figure 6.)

3. 49 CFR&Appendix D of art 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 IAW sections II and IV of this appendix.
Finding:
During the inspection it was noted that at the following locations CP readings were unable to be ascertained:
Casing 267-01-305 and Odorizer 30070. CP technician believes possible cause due to broken lead.
Intermountain Gas Response
A half-cell requires moisture in the soil at the point of contact to create a good electrical connection. Because the soil
conditions were too dry at the time of the inspection, a read was not produced during the Nampa#2 Field Inspection. On
August 24, 2018, the Corrosion Technician returned to casing 26701305, permeated the soil with water and obtained CP
reads on Casing 26701305 of-0.28 volts on the casing and-0.90 volts on the carrier pipe. Additionally,at the last scheduled
inspection on April 18,2018,the reads were-0.675 volts for the casing and-0.885 volts for the carrier pipe.
During the inspection, a negative (cathodic) voltage of at least 0.85 volt was not produced on the odorant flare line at
Odorizer 30070.On August 30,2018,the Corrosion Technician obtained a read of-1.137 volts at Regulator Station 30069
(i.e.the Nampa Gate).The buried pipeline portions of Odorizer 30070,two stainless-tubing lines,are cathodically connected
to Regulator Station 30069. Upon further investigation, the Corrosion Inspector determined the odorant flare line was
shorted to the above ground odorant equipment.It should be noted that odorant flare lines are used to flare off excess odorant
fumes during maintenance and do not transport natural gas as defined in §192.7. On December 10, 2018, the Corrosion
Technician repaired the short between the flare line and the odorant equipment,installed a new lb.magnesium anode and
obtained a CP read of-1.355 volts.
Please contact Josh Sanders at(701)222-7773 with questions or comments.
Respectfully Submitted,
Ali�xj 6L-1�
Pat Darras
Vice President,Engineering&Operations Services
Intermountain Gas Company
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