SOUTHERN NATURAL GAS CO — Gas transmission and gathering — incident on 2016-12-30

Gas transmission and gathering incident in TUSCALOOSA, TUSCALOOSA County, AL. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 4335 NATURAL GAS released, $1,465 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: 20170009.

Operator ID: 18516.

Reported incident date: 12/30/2016 15:08.

Location detail: MP 17.593

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: 12/30/2016, 15:08, CITY OF TUSCALOOSA FIRE DEPARTMENT REPORTED A NATURAL GAS RELEASE TO SOUTHERN NATURAL GAS COMPANY (SNG) GAS CONTROL; 15:20, SNG TECHNICIAN CONFIRMED WITH SNG GAS CONTROL HE WAS IN ROUTE TO THE SNG TUSCALOOSA #1 METER STATION; CUSTOMER (ALAGASCO) TECHNICIAN ARRIVED AT SNG METER STATION AND AT 15:52 CUSTOMER (ALAGASCO) TECHNICIAN CONTACTED SNG GAS CONTROL AND CONFIRMED GAS VENTING FROM SNG METER STATION RELIEF VALVE; APPROXIMATELY 16:35 SNG TECHNICIAN ISOLATED FAILED REGULATOR, THE RELIEF VALVE THEN RESET; 16:41, SNG TECHNICIAN REPORTED TO SNG GAS CONTROL HE HAD ISOLATED THE REGULATOR AND VENTING OF NATURAL GAS WAS TERMINATED; INVESTIGATION FOUND OIL HAD ENTERED REGULATOR PILOT AND BODY OF REGULATOR WHICH CAUSED THE REGULATOR TO FAIL OPEN AS DESIGNED; THE RESULTING INCREASED PRESSURE CAUSED VENTING AT THE RELIEF VALVE; REGULATOR EQUIPMENT WAS CLEANED INTERNALLY AND REPAIRED BY REPLACING SOFT-GOODS; TUSCALOOSA #1 METER STATION WAS RETURNED TO SERVICE 12/31/2016, 00:04; DOCUMENTATION FROM THE CITY OF TUSCALOOSA FIRE DEPARTMENT NOTES THE FIRE DEPARTMENT CONDUCTED AN EVACUATION ON 51ST AVENUE; THIS EVACUATION WAS BASED UPON FIRE DEPARTMENT CRITERIA AND THEIR EVENT KNOWLEDGE AT THE TIME OF THE ALARM. THE DOCUMENTATION DOES NOT SPECIFICALLY IDENTIFY THE EVACUEES NOR DOES THE DOCUMENTATION PROVIDE THE EVACUATION POPULATION; ALL TIMES IN THIS REPORT ARE CST;

PHMSA trend classification: not significant, not serious.

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

PHMSA indexed costs: $17,748 reported total cost, $17,951.82 in 1984 dollars, $23,065.067 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.