NORTHWEST PIPELINE LLC
gas_transmission Incident —
Incident Information
| Report Date | — |
| Operator | NORTHWEST PIPELINE LLC |
| Commodity | — |
| Pipeline Type | gas_transmission |
Location
| State | |
| Coordinates | 40.03891, -109.45346 |
Cause
| Cause | INCORRECT OPERATION |
| Subcause | — |
Casualties
| Fatalities | 0 |
| Injuries | 0 |
Costs
| Property Damage | — |
| Lost Commodity | — |
| Public/Private Damage | — |
| Emergency Response | — |
| Environmental Remediation | — |
| Other Costs | — |
Location Map
Incident Narrative
ON 4/25/23, MOUNTAINWEST PIPELINE RELEASED 5,640 MSCF OF NATURAL GAS DUE TO AN INCORRECTLY INSTALLED SOLENOID WIRING FOR A SUCTION VALVE ON COMPRESSOR UNIT 2. THE SOLENOID WAS NOT PROPERLY TESTED AT THE TIME OF INSTALL. AT APPROXIMATELY 9:50, MOUNTAINWEST PIPELINE GAS CONTROL WAS ALERTED FROM A NEIGHBORING PLANT ABOUT GAS BEING VENTED ON UNIT 2 AT FIDLAR COMPRESSOR STATION. OPERATIONS ARRIVED ON-SITE AT 9:55 AND PERFORMED AN ESD AT 10:47 ON THE STATION AFTER ATTEMPTING TO FIX THE ISSUE WITH THE AUTOMATION'S GROUP. COMPRESSOR UNIT 2 WAS NOT ACTIVE AT THE TIME AND HAD NOT BEEN ACTIVE FOR 5 YEARS. WORK WAS BEING PERFORMED ON THE SOFTWARE OF THE SOLENOID TO UPGRADE THE FIRMWARE WHICH RESULTED IN THE SUCTION VALVE OPENING INSTEAD OF CLOSING. THIS RESULTED IN GAS FLOWING THROUGH THE SYSTEM AND OUT THE VENT VALVE. ATTEMPTS TO CLOSE BOTH THE SUCTION VALVE AND VENT VALVE WERE UNSUCCESSFUL LEADING TO THE ESD. NOTES/ESTIMATIONS: A4) TIME OF INCIDENT REPORTING CRITERIA WAS MET WAS ESTIMATED BASED FLOW RATE AND TIME IT WOULD TAKE TO REACH 3 MMSCF. A7) AMOUNT OF GAS LOSS WAS ESTIMATED BASED ON THE DIFFERENCE BETWEEN INLET METERS VS. OUTLET METERS DATA AT THE STATION.
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.