COLORADO INTERSTATE GAS CO — Gas transmission and gathering — incident on 2018-11-20

Gas transmission and gathering incident in AURORA, ARAPAHOE County, CO. Reported cause: EXCAVATION DAMAGE. Reported consequences: 0 fatalities, 0 injuries, 5962 NATURAL GAS released, $28,414 reported property damage. Operator-reported incident data submitted to PHMSA, generally within 30 days. Records may be supplemented or corrected and do not represent final agency causal findings.

Report number: 20180132.

Operator ID: 2564.

Reported incident date: 11/20/2018 15:13.

Location detail: MP 105+4872

Cause detail: EXCAVATION DAMAGE BY THIRD PARTY

Cause detail: MISCELLANEOUS ROOT CAUSES

Cause detail: ROOT CAUSE NOT LISTED (COMMENT REQUIRED)

Cause detail: ON NOVEMBER 20, 2018 AT 3:13 PM MST COLORADO INTRASTATE GAS COMPANY (CIG) GAS CONTROL RECEIVED A CALL FROM A THIRD-PARTY CONTRACTOR INDICATING THAT WHILE GRADING THEY THE THIRD-PARTY CONTRACTOR HAD HIT AND PUNCTURED A NATURAL GAS PIPELINE. CIG PERSONNEL ARRIVED AT THE LOCATION OF THE LINE STRIKE AT 3:43 PM MST AND CONFIRMED THAT IT WAS ON THE CIG PIPELINE. THE THIRD-PARTY CONTRACTOR STRUCK THE CIG 9A PIPELINE WHILE GRADING THE AREA FOR A NEW HOUSING DEVELOPMENT. THERE WAS AN OPEN ONE CALL TICKET AND CIG DAMAGE PREVENTION PERSONNEL HAD MARKED THE LINE. THE CONTRACTOR HAD PREVIOUSLY AGREED ORALLY AND IN WRITING TO CIG'S REQUEST THAT A CIG REPRESENTATIVE BE ONSITE FOR ANY WORK WITHIN 25 FEET OF OUR PIPELINE ASSETS. FURTHER, THE CONTRACTOR TOLD CIG A FEW DAYS BEFORE THE INCIDENT THAT NO WORK WOULD BE PERFORMED WITHIN 25 FEET OF THE PIPELINE ON THE DAY OF THE LINE STRIKE. DESPITE THE PIPELINE MARKINGS AND THE PRIOR AGREEMENTS, THE THIRD-PARTY CONTRACTOR PROCEEDED WITH GRADING OVER THE PIPELINE WITHOUT NOTIFYING CIG. POST CONFIRMATION BY CIG FIELD PERSONNEL THAT OUR PIPELINE HAD BEEN STRUCK, THEY PROCEEDED TO ISOLATE THE PIPELINE BETWEEN MLV 11 AND 11.9. CIG THEN IMPLEMENTED A BLOW DOWN PROCESS FOR THIS SEGMENT. ONCE THE LEAK SITE WAS DECLARED SAFE AND FREE OF GAS VAPORS CIG PROCEEDED TO MAKE REPAIRS. THE REPAIRS CONSISTED OF REPLACING SIXTY FEET OF PRETESTED TWENTY INCH PIPE. THE REPAIRS WERE COMPLETED ON NOVEMBER 21, 2018. UPON COMPLETING THE REPAIRS CIG IMPLEMENTED A PURGE AND PACK PROCESS FOR THIS SEGMENT. ONCE THE PURGE PROCESS WAS CONFIRMED TO BE COMPLETED THE SEGMENT PRESSURE WAS ALLOWED TO EQUALIZE. THE SEGMENT WAS THEN RETURNED TO GAS CONTROL FOR NORMAL OPERATIONS AND WAS BACK IN SERVICE AT 7:42 PM MST ON NOVEMBER 21, 2018.

PHMSA trend classification: not significant, not serious.

PHMSA standardized cause: EXCAVATION DAMAGE — THIRD PARTY EXCAVATION DAMAGE.

PHMSA indexed costs: $64,252 reported total cost, $47,038.803 in 1984 dollars, $74,517.116 in current-year dollars.

PHMSA trend flags, standardized causes, and indexed costs are analytical fields added to operator-reported incident data. They do not represent final agency causal findings.