WASHINGTON NATURAL GAS CO — Gas distribution — incident on 1996-09-16

Gas distribution incident in MUKILTEO, KING County, WA. Reported cause: DAMAGE BY OUTSIDE FORCES. Reported consequences: 0 fatalities, 0 injuries, $100,000 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: 19960152.

Operator ID: 22189.

Reported incident date: 19960916.

Cause detail: THIS WAS AN ON-GOING JOB THAT HAD BEEN ONE-CALLED SEVERAL TIMES. THE GAS MAIN WAS MARKED CORRECTLY JUST 6 DAYS PRIOR TO THE OCCURENCE OF THE DAMAGE. A CONTRACTOR USING A BULLDOZER ON A STREET IMPROVEMENT JOB WAS REMOVING UNSUITABLE MATERIAL FROM A PORTION OF THE ROADBED WHEN HE TORE A 30" X 3" HOLE IN THE TOP OF A 4" PE MAIN. THE ONE-WAY FEED MAIN WAS SQUEEZED OFF ON THE DOWNSTREAMSIDE OF THE BREAK, THEN THE UPSTREAM SIDE, AFTER GAUGES INDICATED NO PRESSURE REMAINED IN THE SYSTEM. THE RESULT WAS A LOSS OF SERVICE TO 1427 CUSTOMERS.THE MAIN WAS REPAIRED BY 18:30, 9/16/96 AND ALL AFFECTED METERS WERE SHUT OFF AND LOCKED BY 03:00 AM, 9/17/96. GAS WAS REINTRODUCED INTO THE SYSTEM AND RELIGHTS BEGAN IMMEDIATELY, UTILIZING EMPLOYEE'S STATIONED THROUGHOUT THE COMPANY THAT HAVE BEEN QUALIFIED TO PERFORM LIGHT-UPS. RESTORATION OF SERVICE WASCOMPLETED TO ALL AVAILABLE CUSTOMERS BY 23:45, 9/17/96. THE ONE-CALL LOCATION CENTER HAD BEEN NOTIFIED OF THE EXCAVATION WORK AND THE GAS MAIN WAS MARKEDON 9/9 AND 9/10/96 IN THE AREA OF DAMAGE. IT DID NOT APPEAR THAT THE MAIN WAS POT-HOLED BY HAND OR THE LOCATION MARKS MAINTAINED BY THE EXCAVATING CONTRACTOR.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EXCAVATION DAMAGE — THIRD PARTY EXCAVATION DAMAGE.

PHMSA indexed costs: $100,000 reported total cost, $71,973.217 in 1984 dollars, $177,247.882 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.