PUBLIC SERVICE CO OF COLORADO — Gas transmission and gathering — incident on 2017-08-17

Gas transmission and gathering incident in DEL NORTE, RIO GRANDE County, CO. Reported cause: EXCAVATION DAMAGE. Reported consequences: 0 fatalities, 0 injuries, 2951 NATURAL GAS released, $90,000 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: 20170069.

Operator ID: 15931.

Reported incident date: 8/17/2017 10:28.

Location detail: 3714888

Cause detail: EXCAVATION DAMAGE BY OPERATOR'S CONTRACTOR (SECOND PARTY)

Cause detail: EXCAVATION ISSUE

Cause detail: IMPROPER EXCAVATION PRACTICE NOT LISTED ABOVE

Cause detail: ON 8/17/17, A SECOND PARTY MECHANICAL CONTRACTOR STRUCK THE XCEL/PSCO 8IN IGNACIO TO DEL NORTE TRANSMISSION GAS LINE APPROXIMATELY 16 MILES SOUTHWEST OF DEL NORTE, COLORADO. WHILE EXCAVATING A TRENCH INTENDED FOR ELECTRICAL CONDUIT FOR A NEW REMOTE-CONTROLLED VALVE, THE EQUIPMENT OPERATOR STRUCK A 2IN T.D. WILLIAMSON THREAD-O-RING FITTING AT THE 12:00 POSITION ON THE 8IN PIPELINE. AS A RESULT OF THE IMPACT, THE 8IN PIPELINE FAILED, OPENING A 2.5IN DIAMETER HOLE IN THE TOP OF THE PIPE. THE INCIDENT LOCATION IS A REMOTE AREA WITHOUT CELLULAR PHONE SERVICE. THE INCIDENT WAS INITIALLY DISCOVERED BY THE GAS CONTROLLER ON DUTY BY WAY OF SCADA ALARMS AND WAS IMMEDIATELY REPORTED TO OPERATING PERSONNEL. THE DAMAGED PIPELINE SEGMENT WAS ISOLATED BY CLOSING THE MANUALLY OPERATED UPSTREAM AND DOWNSTREAM MAINLINE VALVES. UPON COMPLETION OF THE ELECTRICAL WORK, THE FINAL GRADE OF THE LOCATION WILL BE RAISED TO REACH A MINIMUM OF 36IN OF COVER. THE INITIAL NRC NUMBER IS #1187585 AND THE 48-HR FOLLOW UP NUMBER IS #1187701.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EXCAVATION DAMAGE — OPERATOR/CONTRACTOR EXCAVATION DAMAGE.

PHMSA indexed costs: $105,250 reported total cost, $56,170.159 in 1984 dollars, $126,311.605 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.