DTE GAS COMPANY — Gas transmission and gathering — incident on 2018-03-15

Gas transmission and gathering incident in MILFORD, OAKLAND County, MI. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 7500 NATURAL GAS released, $0 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: 20180042.

Operator ID: 12408.

Reported incident date: 3/15/2018 0:04.

Location detail: 1008

Cause detail: MALFUNCTION OF CONTROL/RELIEF EQUIPMENT

Cause detail: ON MARCH 15, 2018, AN ESD OCCURRED AT MILFORD COMPRESSOR STATION RESULTING IN A RELEASE OF NATURAL GAS AT VENT VALVE 1008. VENT VALVE 1008 WAS LOCKED CLOSED TO PREVENT RECURRENCE DURING INVESTIGATION. MILFORD COMPRESSOR STATION HAS ADEQUATE PROTECTION IN THE EVENT OF AN ESD. ON MARCH 23, 2018, IT WAS DETERMINED THAT THE SOLENOID CASING THAT CONTROLS THE VALVE HAD AN ACCUMULATION OF WATER. THE SEAL PROTECTING THE SOLENOID WAS NOT FULLY SEALED. WATER WAS REMOVED AND THE SEAL WAS FIXED. ADDITIONAL INVESTIGATION IS IN PROGRESS TO REVIEW ELECTRONICS OF THE SYSTEM. UPON FURTHER INVESTIGATION, IT WAS FOUND THAT AN EXCESS OF CURRENT TO THE CONTROL MODULE CAUSED THE SOLENOID CONTROLLING VALVE 1008 TO FAIL. THE CONTROL MODULE WAS REPLACED AND UPGRADED. DTE CONTROL MAINTENANCE TESTED ALL THE REMAINING CONTROL MODULES FOR VENT VALVES AT MILORD. IT WAS FOUND THAT ALL THE CURRENT READINGS WERE WITHIN THE OUTPUT LIMITS OF THE MODULES BEFORE PUTTING THE STATION BACK INTO SERVICE. RESULTS OF TESTING AND REPLACEMENT OF MODULES HAS BEEN SUPPLIED TO THE MICHIGAN PUBLIC SERVICE COMMISSION. DTE GAS BELIEVES THAT WITH THESE ACTIONS, WE DO NOT EXPECT A REPEAT OCCURRENCE. MILFORD COMPRESSOR STATION WAS PUT BACK INTO SERVICE ON APRIL 12, 2018.

PHMSA trend classification: not significant, not serious.

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

PHMSA indexed costs: $22,500 reported total cost, $21,010.638 in 1984 dollars, $25,797.872 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.