PHILADELPHIA GAS WORKS — Gas distribution — incident on 2008-02-07

Gas distribution incident in PHILADELPHIA, PHILADELPHIA County, PA. Reported cause: 3. Reported consequences: 0 fatalities, 0 injuries, $925,000 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: 20080039.

Operator ID: 15469.

Reported incident date: 2/7/2008.

Cause detail: EARTH MOVEMENT

Cause detail: INCIDENT EXECUTIVE SUMMARY 709 SOUTH SIXTH ST. FEBRUARY 7, 2008 THE FOLLOWING IS AN ACCOUNT OF THE INCIDENT WHICH OCCURRED IN THE QUEEN VILLAGE SECTION OF PHILADELPHIA, 709 SOUTH SIXTH STREET ON THURSDAY AFTERNOON, AT 1602 HOURS. THURSDAY FEBRUARY 7, 2008 TIME 1602 - INITIAL CALL THE INITIAL CALL TO PGW WAS MADE BY THE PHILADELPHIA FIRE DEPARTMENT AND WAS REPORTED TO PGW TO RESPOND TO A BUILDING COLLAPSE, ONE ALARM FIRE, ENGINE ON THE WAY, INJURIES UNKNOWN AT THIS TIME. 1602 - 1609 � PGW INITIAL PERSONNEL DISPATCHING TIME PGW FIELD OPERATIONS INITIALLY DISPATCHED THE FOLLOWING: 1604 - DISTRIBUTION CREW 1602 - DISTRIBUTION SUPERVISOR 1604 - GREASE EQUIPMENT. 1604 - FSD SUPERVISOR, 1609 - FSD TECHNICIAN, 1615 � FIRST PGW EMPLOYEE ON LOCATION WITHIN 13 MINUTES OF THE INITIAL CALL THE FIRST PGW EMPLOYEE ARRIVED ON LOCATION AND PROVIDED A PRELIMINARY REPORT OF A HOUSE COLLAPSE AND AN ENSUING FIRE. VISUAL OBSERVATION OF A GAS FIRE WAS NOT INDICATED. NO INDICATION OF A GAS LEAK (ODOR OR READINGS) AT THIS TIME. NO INJURIES REPORTED AT THIS TIME. 1620 � FIRST EMERGENCY ACTION 707 S. 6TH STREET WAS SHUT OFF. THE FIRST OF FIVE BUILDINGS WERE SHUT OFF AS AN EMERGENCY ACTION. 1625 � SECOND EMERGENCY ACTION 711 S. 6TH STREET GAS WAS SHUT OFF. THIS ENSURED THAT THE FIRST TWO BUILDINGS ALONG SIDE OF THE INCIDENT ADDRESS, 709 S. 6TH STREET, WERE SHUT OFF AS SAFETY MEASURES. OTHER PREMISES WERE SHUT OFF SHORTLY THEREAFTER, 705 S. 6TH STREET TO 715 S. 6TH STREET. CONTINUED ACTIONS � PGW CONTINUED TO INVESTIGATE AND CONTINUALLY MONITOR FOR ANY SIGNS OF A GAS LEAK OR POTENTIAL MIGRATION TO OTHER STRUCTURES ON THE BLOCK. REPORTS CONTINUED THAT THERE WERE NO INJURIES. GENERAL SUPERVISOR DISTRIBUTION WAS DESIGNATED AS THE INCIDENT COMMANDER FOR PGW ACTION AND REPORTED TO DEPUTY CHIEF OF THE PHILADELPHIA FIRE DEPARTMENT. THERE WERE REPORTS OF A GAS ODOR FROM FIRE FIGHTERS ABOVE GROUND LEVEL AND OCCASIONALLY ON THE GROUND BY PGW WORKERS. THE PUC WAS NOTIFIED OF A POTENTIAL GAS INCIDENT AT 1744. THE NATIONAL RESPONSE CENTER IN WASHINGTON WAS NOTIFIED OF A POTENTIAL GAS LEAK INCIDENT AS PER �191.5 AT 1832 THAT EVENING. 1725 � ORDER TO SHUT DOWN GAS. CHIEF GROGAN ORDERED THE GAS IN FRONT OF 709 S. 6TH STREET BE SHUT OFF. DUE TO FIRE FIGHTING EQUIPMENT ON SCENE, THE EMERGENCY ON LOCATION WAS BROUGHT IN TO A SUITABLE STAGING AREA; AIR COMPRESSORS AS WELL. PREPARATIONS TO GREASE WERE MADE AT THE HEAD OF SERVICE TO 705 S. 6TH STREET AND 715 S. 6TH STREET. 1744 � GAS OFF THE GAS MAIN WAS SHUT DOWN BY GREASE INJECTION. ZERO GAS FLOW CHECKS CONFIRMED POSITIVE SHUT DOWN INSIDE THE PROPERTIES OF 707 S. 6TH STREET AND 713 S. 6TH STREET. 2300 � CUT AND CAP AS PER PGW PROCEDURES, THE MAIN WAS PHYSICALLY DISCONNECTED BY CUTTING AND CAPPING. FINAL LEAK SURVEY OF THE ENTIRE BLOCK WAS CONDUCTED AND NO READINGS WERE FOUND. AT THIS TIME THE FIRE MARSHALL CONCLUDED THE DAY�S INVESTIGATION AND CALLED FOR CONTINUATION THE NEXT MORNING. FRIDAY, FEBRUARY 8, 2008 INVESTIGATION PGW ON SCENE DURING THE FIRE MARSHALL (FM) INVESTIGATION OF THE EXPLOSION/FIRE AT 709 S. 6TH STREET. FIRE MARSHALL CLAY WAS THE LEAD INVESTIGATOR IN CHARGE. PUC SAFETY DIVISION WAS REPRESENTED BY PAUL METRO, PETE STANLEY AND MICHAEL NYGUEN. AFTER DEBRIS AND UNSAFE OVERHANGING STRUCTURES WERE REMOVED IN FRONT OF THE PROPERTY, PGW CONTINUED TO ASSIST THE FM BY PREPARING AND TESTING THE MAIN AND SERVICES ABANDONED THE PREVIOUS NIGHT. A 6� WATER COLUMN PRESSURE TEST (OPERATING PRESSURE AT THE TIME) WAS PLACED ON THE MAIN AND SERVICES. THIS TEST FAILED. WHEN DEBRIS WAS REMOVED IN FRONT OF 709 S. 6TH STREET, PGW PROVIDED BARHOLES FOR LEAK INVESTIGATION. HIGHEST READING FOUND WAS A 3% GAS READING IN A BARHOLE. THIS WAS ASSUMED TO BE RESIDUAL GAS FROM THE DISCONTINUED MAIN. SINCE THE MAIN AND SERVICES FAILED TEST, THE NEXT STEP OF THE INVESTIGATION WAS TO DISCONNECT THE SERVICES AND TEST THEM INDIVIDUALLY. THEY ALL PASSED AN AIR TEST. THE MAIN WAS THEN TESTED AND THIS TEST FAILED. THE FIRE MARSHALL CONCLUDED THE INVESTIGATION AND SCHEDULED CONTINUATION THE FOLLOWING DAY. SATURDAY, FEBRUARY 9, 2008 INVESTIGATION STEVEN GROEBER, DIRECTOR, FIELD OPERATIONS REPRESENTING PGW, FIELD MARSHALL CLAY, PETE STANLEY AND MICHAEL NYGUEN WERE ON LOCATION SATURDAY, FEBRUARY 9, 2008 AT 0700. THE INVESTIGATION CONTINUED BY SETTING UP A FLOW LOSS TEST ON THE MAIN. FLOW LOSS WAS MEASURED AT 150 � 200 CFH. VACUUM EXCAVATION WAS PERFORMED IN FRONT OF 709 S. 6TH STREET. AT 0915 A 6� CAST IRON, BROKEN MAIN WAS UNCOVERED ALMOST CENTER TO THE PROPERTY OF 709 S. 6TH STREET. THE MAIN WAS CLEANED, SCALED AND RECORDED (PHOTOS) IN PLACE. SOAPY WATER TEST OF THE MAIN INDICATED THAT THE MAIN WAS BROKEN ON THE TOP FROM 9AM TO 3PM. THE BOTTOM OF THE MAIN WAS NOT LEAKING. A SLEEVE WAS PLACED AROUND THE BREAK AND THE PRESSURE TEST THEN HELD; CONFIRMATION THAT THAT WAS THE ONLY BREAK ON THE LINE. PUC REPRESENTATIVES DIRECTED PGW TO CUT THE PIPE 12� EITHER SIDE OF THE BREAK. THE SECTION WAS CUT OUT AND REMOVED. THIS ALONG WITH OTHER EXCAVATED PIPING FROM THE SERVICES WERE TAGGED AND PLACED IN THE PGW EVIDENCE LOCKER. ALL EXCAVATIONS MADE BY PGW WERE BACKFILLED AND STEEL PLATE WAS LEFT IN THE FOOTWAY IN FRONT OF 709 S. 6TH STREET SO HEAVY EQUIPMENT COULD ACCESS THE BUILDING FOR THE FINAL INVESTIGATION. THE FIRE MARSHALL INDICATED THAT HE WOULD CHECK ALL GAS APPLIANCES BEFORE MAKING ANY CONCLUSIONS. ON SUNDAY, FEBRUARY 10, THE FIRE MARSHALL CONTINUED THE INVESTIGATION TO EXAMINE APPLIANCES AND CONDITIONS WITHIN THE STRUCTURE (709). THE FIRE MARSHALL REPORTED NO RECOGNIZABLE PROBLEMS WITH THE APPLIANCES. ON MONDAY MORNING, FEBRUARY 11 THE FIRE MARSHALL�S OFFICE ANNOUNCED THAT THE CAUSE OF THE EXPLOSION WAS A BREAK IN PGW�S LINE.

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

PHMSA standardized cause: NATURAL FORCE DAMAGE — EARTH MOVEMENT.

PHMSA indexed costs: $925,000 reported total cost, $515,716.63 in 1984 dollars, $1,270,051.339 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.