COLORADO INTERSTATE GAS CO — Gas transmission and gathering — incident on 2016-01-02

Gas transmission and gathering incident in Not Within a Municipality, ARAPAHO County, CO. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 35392 NATURAL GAS released, $14,000 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: 20160010.

Operator ID: 2564.

Reported incident date: 1/2/2016 2:53.

Location detail: MP 5 PLUS 498

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: 02:53 CIG TOTEM STATION NOTICED PRESSURE CHANGE AT LATIGO STATION AND CALLED OUT TECHNICIANS TO RESPOND; CIG GAS CONTROL ALSO NOTICED PRESSURE CHANGE; 03:24 TECHNICIANS ARRIVED AT LATIGO STATION AND CONFIRMED TWO 6-INCH VENT VALVES WERE RELEASING NATURAL GAS; TECHNICIANS ATTEMPTED TO STOP THE NATURAL GAS RELEASE BY USE OF STATION ESD SYSTEM; STATION ESD SYSTEM DID NOT FUNCTION PROPERLY; 03:30 A LOCAL FIRE CHIEF ARRIVED, NOTIFIED BY LANDOWNERS; BY THIS TIME LANDOWNERS HAD ALSO CALLED CIG GAS CONTROL; 03:34 TECHNICIANS COMPLETED CLOSING STATION BLOCK VALVE THUS STOPPING THE RELEASE OF NATURAL GAS; WITH THE VALVE CLOSURE, THE STATION WAS SHUT IN AND ISOLATED; INVESTIGATION FOUND FROZEN AIR SUPPLY LINES INCLUDING FROZEN INSTRUMENT AIR LINES; SAID FROZEN LINES ALLOWED THE TWO 6-INCH VENT VALVES TO OPEN; SAID FROZEN LINES PREVENTED THE ESD SYSTEM FROM PROPER FUNCTION; THE AIR SUPPLY SYSTEM WAS FLUSHED; A NEW AIR DRYER WAS INSTALLED IN THE AIR SUPPLY SYSTEM; LATIGO STATION SHUT IN WAS TERMINATED 10:00, 01/07/2016;

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — MALFUNCTION OF CONTROL/RELIEF EQUIPMENT.

PHMSA indexed costs: $145,000 reported total cost, $145,872.862 in 1984 dollars, $188,325.555 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.