NIAGARA MOHAWK POWER CORP
gas_distribution Incident — OSWEGO CITY, NY — April 29, 2019
Incident Information
| Incident Date | April 29, 2019 |
| Operator | NIAGARA MOHAWK POWER CORP |
| Commodity | NATURAL GAS |
| Pipeline Type | gas_distribution |
Location
| City | OSWEGO CITY |
| State | NY |
| County | OSWEGO |
| Coordinates | 43.45362, -76.53305 |
Cause
| Cause | INCORRECT OPERATION |
| Subcause | "VALVE LEFT OR PLACED IN WRONG POSITION, BUT NOT RESULTING IN AN OVERPRESSURE" |
Casualties
| Fatalities | 0 |
| Injuries | 0 |
Costs
| Property Damage | $0 |
| Emergency Response | $0 |
| Other Costs | $0 |
Location Map
Incident Narrative
"ON 4/29/2019 A ROUTINE ANNUAL PERFORMANCE TEST WAS CONDUCTED ON A 90 PSIG REGULATOR STATION, GRS-824-228) IN OSWEGO, NY. UPON COMPLETION OF THE RELIEF VALVE TEST, THE CREW LEFT THE STATION. APPROX. 2 HOURS LATER THE RELIEF VALVE BEGAN VENTING GAS. THE RELIEF VALVE ASSOCIATED WITH THAT REGULATOR STATION VENTED GAS FROM APPROX. 2:53 PM (14:53) UNTIL 3:47 PM (15:47). THE ABNORMAL OPERATING CONDITION (AOC) WAS DETECTED BY SCADA AND COMMUNICATED FROM THE CONTROL CENTER TO FIELD PERSONNEL. . FIELD PERSONNEL RETURNED TO THE STATION AND DETERMINED THAT THE RELIEF VALVE PILOT HAD NOT BEEN RETURNED TO THE CORRECT OPERATING POSITION AND THEN CORRECTED THE CONDITION. VOLUME OF VENTED GAS WAS APPROX. 3,650,000 CFH BASED ON CAPACITY OF THE VALVE. OUTLET MAOP OF THE STATION IS 90 PSIG. RELIEF VALVE SETTING WAS 94 PSIG (WITH MAXIMUM OF 99 PSIG). NO CUSTOMERS WERE IMPACTED BY THIS RELEASE OF GAS. (NO OUTAGES NOR OVERPRESSURIZATION OCCURRED.)"
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.