PHMSA Report 20190004 - ALGONQUIN GAS TRANSMISSION, L.L.C. (SPECTRA ENERGY PARTNERS, LP) — Gas transmission and gathering — incident on 2018-12-13 | Regulus

Gas transmission and gathering incident in SOUTHINGTON, HARTFORD County, CT. Reported cause: INCORRECT OPERATION. Reported consequences: 0 fatalities, 0 injuries, 9.975 NATURAL GAS released, $198,467 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: 20190004.

Operator ID: 288.

Reported incident date: 12/13/2018 9:38.

Location detail: 4.229

Cause detail: EQUIPMENT NOT INSTALLED PROPERLY

Cause detail: ORIGINAL REPORT: 48 HR NRC REPORT 1233090 AT APPROXIMATELY 9:38 AM EST ON DECEMBER 13, 2018, A GAS UTILITY COMPANY NOTIFIED ENBRIDGE OF A POSSIBLE NATURAL GAS RELEASE DISCOVERED DURING A LEAK SURVEY IN CLOSE PROXIMITY TO ALGONQUIN GAS TRANSMISSION'S (AGT) NATURAL GAS PIPELINE AT SOUTHINGTON, CONNECTICUT. ENBRIDGE PERSONNEL WERE IMMEDIATELY DISPATCHED TO THE SITE AT ABOUT 10:30 AM EST. AGT'S INITIAL LEAK SURVEYS WAS INCONCLUSIVE BECAUSE OF THE LOW GAS LEVELS. AGT PERFORMED FURTHER TESTS WITH AN ETHANE GAS DETECTOR AND CONCLUSIVELY DETERMINED THE ORIGIN OF THE GAS RELEASE WAS FROM AGT'S PIPELINE FACILITIES AT ABOUT 2:00 PM EST. AGT PROACTIVELY MADE THE NRC CALL AT 2:36 PM EST AFTER DETERMINING THE COST OF EXCAVATION ACTIVITIES TO REPAIR THE LEAK WOULD EXCEED THE $50,000. AGT MADE EMERGENCY ONE CALL TICKETS AND REQUESTS FROM THE CITY OF SOUTHINGTON WERE PUT IN FOR EXCAVATION ACTIVITIES. AGT MOBILIZED CONTRACTORS TO BEGIN EXCAVATION ACTIVITIES AT THE SITE ON DECEMBER 14 AT ABOUT 8:00 AM. AGT UPON EXCAVATION, ENBRIDGE DETERMINED THAT THE APPARENT CAUSE OF THE LEAK WAS FROM A 1INCH THREADED NIPPLE. THE PIPE WAS REPLACED ON JANUARY 9-10, 2019. THE CAUSE OF THE RELEASE IS UNDER INVESTIGATION. SUPPLEMENTAL REPORT: THE APPARENT CAUSE IS THE 1 INCH THREADED NIPPLE WAS NOT PROPERLY TORQUED INTO THE THREAD-O-LET, RESULTING IN THE NATURAL GAS LEAK.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: INCORRECT OPERATION — INCORRECT INSTALLATION.

PHMSA indexed costs: $198,800 reported total cost, $95,116.48 in 1984 dollars, $233,858.632 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.