NORTHERN STATES POWER CO OF MINNESOTA — Gas distribution — incident on 2019-02-14

Gas distribution incident in MOORHEAD, CLAY County, MN. Reported cause: OTHER OUTSIDE FORCE DAMAGE. Reported consequences: 0 fatalities, 0 injuries, 3852 NATURAL GAS released, $25,000 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: 20190027.

Operator ID: 31636.

Reported incident date: 2/14/2019 23:21.

Location detail: 8 ST S AND 16 AVE S

Cause detail: DAMAGE BY CAR, TRUCK, OR OTHER MOTORIZED VEHICLE/EQUIPMENT NOT ENGAGED IN EXCAVATION

Cause detail: ON FEBRUARY 14, 2019, A SNOW PLOW HIT ABOVEGROUND PIPING FOR A PRESSURE RECORDING CHART AT A REGULATOR STATION THAT WAS INSTALLED IN A VAULT. THE IMPACT DAMAGED PIPING IN THE VAULT CAUSING THE REGULATOR TO FAIL WHICH RESULTED IN THE ACTIVATION OF THE RELIEF VALVE. THE MAOP OF THE SYSTEM IS 25 PSIG AND THE HIGHEST PRESSURE OBSERVED WAS 30.5 PSIG. AT APPROXIMATELY 12:00 ON FEBRUARY 15, 2019 THE SYSTEM WAS SHUT-IN BY CLOSING AN EMERGENCY VALVE, CAUSING AN OUTAGE TO 950 CUSTOMERS. REPAIRS WERE INITIALED AT APPROXIMATELY 16:00 ON FEBRUARY 15, 2019. REPAIRS WERE COMPLETED BY 19:30, THE SYSTEM WAS STARTED UP AND LEAK SURVEYED. CUSTOMER RELIGHTS STARTED AT APPROXIMATELY 23:00 AND CONTINUED UNTIL FEBRUARY 16, 2019 AT 16:00. ADDITIONAL LEAK SURVEYS WERE CONDUCTED FEBRUARY 16 STARTING AT 19:00. AFTER THE SECOND SURVEY NO FURTHER LEAKS WERE DISCOVERED. ON FEBRUARY 17, STARTING AT 11:00, ONE MORE SURVEY WAS CONDUCTED WITH NO FURTHER LEAKS DISCOVERED.

PHMSA trend classification: significant incident, not serious, not fire-first.

PHMSA standardized cause: OTHER OUTSIDE FORCE DAMAGE — VEHICLE NOT ENGAGED IN EXCAVATION.

PHMSA indexed costs: $362,773 reported total cost, $179,418.763 in 1984 dollars, $420,582.355 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.