TEXAS EASTERN TRANSMISSION, LP (SPECTRA ENERGY PARTNERS, LP) — Gas transmission and gathering — incident on 2019-01-31

Gas transmission and gathering incident in MARIETTA, LANCASTER County, PA. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 1782 NATURAL GAS released, $200 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: 20190026.

Operator ID: 19235.

Reported incident date: 1/31/2019 11:00.

Location detail: 169.92

Cause detail: DEFECTIVE OR LOOSE TUBING OR FITTING

Cause detail: ORIGINAL REPORT: 48 HR NRC 1237186 AT APPROXIMATELY 11:00 AM EST ON JANUARY 31, 2019, A NATURAL GAS RELEASE WAS DISCOVERED FROM A RELIEF VALVE AT MARIETTA COMPRESSOR STATION ON THE TEXAS EASTERN TRANSMISSION (TETLP) SYSTEM IN LANCASTER COUNTY, PA. THE INITIAL GAS LOSS WAS DETERMINED TO BE LESS THAN THE REPORTING THRESHOLD. THE APPARENT CAUSE WAS A TUBING FITTING UNDER A RELIEF VALVE SNAPPING OFF DUE TO VIBRATION, WHICH CAUSED THE RELIEF VALVE 305-10 TO ACTIVATE AND VENT GAS TO ATMOSPHERE. THE GAS LOSS WAS LATER REVISED ON FEBRUARY 6, 2019 AFTER IT WAS DETERMINED THAT DURING STATION ESD, THE MARIETTA STATION 36"X30" SUCTION VALVE #2-6290 DID NOT CLOSE AS INTENDED DUE TO FREEZING IN THE VALVE CONTROLS. THE REVISED GAS LOSS EXCEEDED THE REPORTING THRESHOLD. AFTER CONSULTATION WITH PHMSA ON FEBRUARY 6, 2019, PHMSA RECOMMENDED THAT ENBRIDGE MAKE THE NRC NOTIFICATION. THE AFFECTED PART OF MARIETTA STATION WAS RETURNED TO SERVICE BY 9:12 PM EST ON JANUARY 31, 2019. SUPPLEMENTAL REPORT: AT APPROXIMATELY 11:00 AM EST ON JANUARY 31, 2019, A NATURAL GAS RELEASE WAS DISCOVERED FROM A RELIEF VALVE AT MARIETTA COMPRESSOR STATION ON THE TEXAS EASTERN TRANSMISSION (TETLP) SYSTEM IN LANCASTER COUNTY, PA. THE ESD SYSTEM WAS ACTIVATED TO ISOLATE THE LEAK IMMEDIATELY AFTER THE LEAK WAS IDENTIFIED. THE INITIAL GAS LOSS WAS DETERMINED TO BE APPROXIMATELY 1,782 MCF, LESS THAN THE REPORTING THRESHOLD. THE APPARENT CAUSE WAS THE FAILURE OF A TUBING FITTING UNDER A RELIEF VALVE DUE TO VIBRATION, WHICH CAUSED THE RELIEF VALVE 305-10 TO ACTIVATE AND VENT GAS TO ATMOSPHERE. ON FEBRUARY 5, DURING THE INVESTIGATION OF THIS EVENT, IT WAS DETERMINED THE MARIETTA STATION 36"X30" SUCTION VALVE #2-6290 DID NOT CLOSE AS INTENDED DUE TO FREEZING IN THE VALVE CONTROLS, RESULTING IN A GAS LOSS VOLUME GREATER THAN ORIGINALLY ESTIMATED. THE GAS LOSS WAS REVISED TO APPROXIMATELY 4,200 MCF ON FEBRUARY 5, 2019. THE REVISED GAS LOSS EXCEEDED THE REPORTING THRESHOLD. AFTER CONSULTATION WITH PHMSA ON FEBRUARY 6, 2019, PHMSA RECOMMENDED THAT ENBRIDGE MAKE THE NRC NOTIFICATION. THE NRC NOTIFICATION WAS MADE ON FEB. 6, AS RECOMMENDED BY PHMSA. THE AFFECTED PART OF MARIETTA STATION WAS RETURNED TO SERVICE BY 9:12 PM EST ON JANUARY 31, 2019.

PHMSA trend classification: not significant, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — DEFECTIVE OR LOOSE TUBING/FITTING.

PHMSA indexed costs: $12,210 reported total cost, $12,545.023 in 1984 dollars, $15,519.1 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.