NORTHERN NATURAL GAS CO
gas_transmission Incident — — November 12, 2021
Incident Information
| Incident Date | November 12, 2021 |
| Operator | NORTHERN NATURAL GAS CO |
| Commodity | NATURAL GAS |
| Pipeline Type | gas_transmission |
Location
| State | |
| Coordinates | 42.28200, -93.28154 |
Cause
| Cause | INCORRECT OPERATION |
| Subcause | EQUIPMENT NOT INSTALLED PROPERLY |
Casualties
| Fatalities | 0 |
| Injuries | 0 |
Costs
| Property Damage | $1,700,181 |
| Emergency Response | $840 |
| Other Costs | $0 |
Location Map
Incident Narrative
"ON NOVEMBER 12, 2021, NEW VALVES WERE BEING MANIPULATED FOR COMMISIONING AND LUBRICATION. AT 10:30, A 30 INCH BYPASS VALVE WAS MANIPULATED WHEN THEN GROUND WAS REPORTED TO RAISE AND SETTLE WITH A MUFFLED SOUND. THE ON-SITE PERSONNEL EVACUATED THE LOCATION TO REPORT THE EVENT. INITIAL REPORTING DID NOT SEE ANY PRESSURE CHANGES ON SCADA, AND DUE TO EXTREMLEY HIGH WINDS, NO VISUAL OR AUDIBLE INDICATIONS COULD BE MADE OF VENTING GAS. A PLAN WAS CREATED TO REDUCE PRESSURE TO 600 POUNDS FOR THE B, C AND D LINES AS THEY WERE ALL IN COMMON AT THE LOCATION. AT 21:00, IT WAS REPORTED THAT AS TECHNICIANS APPROACHED THE VALVE SETTING, THE LEL MONITORING EQUIPMENT DETECTED GAS APPROXIMATELY 100 YARDS UPWIND OF THE VALVE ASSEMBLY. THE PIPELINE WAS ISOLATED AT 1555 ON NOVEMBER 14, 2021. EXCAVATION OF THE VALVE FOUND THAT A 1.5 INCH DIAMETER BODY BLEED PLUG WAS MISSING, CONCLUDING IT WAS NOT INSTALLED OR IMPROPERLY INSTALLED."
About This Pipeline Incident
Pipeline incident data is reported to the Pipeline and Hazardous Materials Safety Administration (PHMSA). All significant incidents involving fatalities, injuries, or property damage over $50,000 must be reported.