CONSUMERS ENERGY CO — Gas transmission and gathering — incident on 2018-09-02

Gas transmission and gathering incident in MCBAIN, MISSAUKEE County, MI. Reported cause: EQUIPMENT FAILURE. Reported consequences: 0 fatalities, 0 injuries, 3200 NATURAL GAS released, $2,673,007 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: 20180097.

Operator ID: 2748.

Reported incident date: 9/2/2018 22:04.

Location detail: MCBAIN DEHY

Cause detail: OTHER EQUIPMENT FAILURE

Cause detail: ON SEPTEMBER 2, 2018 AT APPROXIMATELY 22:04 CONSUMERS ENERGY GAS CONTROLLER DISPATCHED AN INSTRUMENT MECHANIC TO THE MCBAIN CITY GATE BECAUSE OF ERRATIC READINGS ON THE TRANSMITTERS AT THIS LOCATION. THE MCBAIN CITY GATE IS LOCATED IN MCBAIN, MICHIGAN (MISSAUKEE COUNTY). THE MECHANIC ARRIVED AT THE MCBAIN CITY GATE AT APPROXIMATELY 22:47 AND OBSERVED A FIRE AT/NEAR THE DEHYDRATION UNIT BUILDING. THE MECHANIC NOTIFIED THE FIELD LEADER AND REQUESTED ADDITIONAL SUPPORT TO ISOLATE THE PIPELINE SEGMENT SUPPLYING THE UNIT. ADDITIONAL RESOURCES ARRIVED AT THE 80-W VALVE SITE AT APPROXIMATELY 23:13 AND THE MECHANICS SIMULTANEOUSLY CLOSED THE VALVES AT 80-W AND MCBAIN CITY GATE TO ISOLATE THE GAS FLOW TO THE DEHYDRATION UNIT. THE FIRE CONTINUED AS THE AS THE PIPELINE DEPRESSURIZED AND THEN WAS EXTINGUISHED. THERE WERE NO FATALITIES OR INJURIES AS A RESULT OF THE INCIDENT. THE MCBAIN FIRE DEPARTMENT WAS ON SCENE AND PRELIMINARY INVESTIGATION DETERMINED A LIGHTNING STRIKE TO BE THE CAUSE. CONSUMERS ENERGY ALSO RECEIVED A REPORT FROM STRIKENET� CONFIRMING THE PRESENCE OF 22 CLOUD-TO-GROUND LIGHTNING STRIKES WERE DETECTED WITHIN 2 MILES OF THE PROPERTY ON SEPTEMBER 2, 2018. NEW VALVES WERE INSTALLED ON THE WELL LINES (R-178 AND R-179) AND A TEMPORARY HOSE TO THE 2" BLOWDOWN FOR THE LINE THAT SUPPLIES THE MCBAIN CITY GATE WAS INSTALLED. THE LINE WAS RE-PRESSURIZED ON SEPTEMBER 3, 2018 AT APPROXIMATELY 04:44. THE INCIDENT RESPONSE AND TEMPORARY REPAIRS WERE COMPLETED WITH NO CUSTOMER IMPACT AND/OR LOSS OF SERVICE. THE INLET AND OUTLET VALVES TO THE DEHYDRATION UNIT WERE BLIND FLANGED AND THE SYSTEM WAS BYPASSED TO SUPPLY THE LAKE CITY AND MCBAIN CITY GATES. AN ACTION PLAN WILL BE DEVELOPED TO PREPARE FOR WINTER OPERATIONS. AN INTERNAL TEAM WAS ASSEMBLED TO COMPLETE A ROOT CAUSE INVESTIGATION AND IDENTIFY COUNTERMEASURES TO MINIMIZE FUTURE OCCURRENCES. A ROOT CAUSE INVESTIGATION CONCLUDED THE ORIGIN OF THE FIRE WAS AT OR NEAR THE DEHYDRATION UNIT AND MAY HAVE BEEN THE RESULT OF AN EQUIPMENT FAILURE AT A KIMRAY CONTROLLER CAUSING THE FUEL TRAIN REGULATOR TO CONTINUE TO FEED THE FUEL TO THE BURNER, LEADING THE DIETHYLENE GLYCOL TO BOIL OVER AND IGNITE. HOWEVER, DUE TO THE LACK OF PHYSICAL EVIDENCE THE EXACT CAUSE REMAINS UNDETERMINED. THE DEHYDRATION UNIT WAS IN-SERVICE WHILE THE RIVERSIDE STORAGE FIELD WAS SHUT IN. LEAVING THE UNIT IN SERVICE ALLOWS CONSUMERS ENERGY TO CONTINUE TO PROVIDE REQUIRED QUALITY OF GAS TO THE CITY GATES. SEVERAL FACTORS THAT MAY HAVE CAUSED OR CONTRIBUTED TO THE SEVERITY OF THE INCIDENT HAVE BEEN OUTLINED IN THE ROOT CAUSE REPORT AND ACTION ITEMS TO PREVENT RE-OCCURRENCE HAVE BEEN IMPLEMENTED.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EQUIPMENT FAILURE — OTHER EQUIPMENT FAILURE.

PHMSA indexed costs: $2,688,873 reported total cost, $1,288,730.995 in 1984 dollars, $3,162,913.239 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.