LACLEDE GAS CO — Gas distribution — incident on 2010-01-12

Gas distribution incident in SPANISH LAKE, ST LOUIS County, MO. Reported cause: OTHER OUTSIDE FORCE DAMAGE. Reported consequences: 0 fatalities, 0 injuries, 5747 NATURAL GAS released, $93,802 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: 20100087.

Operator ID: 11032.

Reported incident date: 1/12/2010 11:40.

Location detail: 1829 DUNN ROAD

Cause detail: OTHER OUTSIDE FORCE DAMAGE

Cause detail: A 2-INCH STEEL NATURAL GAS MAIN WAS EXPOSED IN AN EXCAVATION BY A CONTRACTOR PREPARING TO INSTALL A WATER MAIN ON DECEMBER 16, 2009 . THE 2-INCH LINE WAS CONNECTED TO A 2-INCH VALVE JUST BEYOND THE EXCAVATION. THE EXCAVATION WAS QUICKLY BACKFILLED THE SAME DAY IT WAS EXCAVATED. IN THE DAYS FOLLOWING THE BACKFILL, HEAVY RAIN SATURATED THE AREA AND FILLED THE VOIDS CREATED BY THE RECENT EXCAVATION WITH MOISTURE. THIS WAS QUICKLY FOLLOWED BY EXTREMELY COLD TEMPERATURES. A LEAK WAS REEORTED BY THE PUBLIC IN THE AREA OF THE DECEMBER 16 EXCAVATION, ON JANUARY 12, 2010. DURING REPAIR THE MAIN REMAINED ACTIVE IN ORDER TO MAINTAIN SERVICE TO CUSTOMERS. ON JANUARY 13, 2010, IT WAS ESTIMATED THAT THE COST OF REPAIR AND THE RELEASED NATURAL GAS WOULD EXCEED $50,000. A NOTIFICATION WAS THEN MADE TO THE NATIONAL RESPONSE CENTER WHILE NATURAL GAS WAS STILL BEING BEING RELEASED AND REPAIRS WERE ON-GOING. THE BODY OF THE 2-INCH VALVE AT THE FLANGE WAS FOUND CRACKED ON JANUARY 14, 2010, FROM SOIL STRESS. REPAIR CREWS ESTIMATED THE DEPTH OF FROST IN THE PREVIOUSLY EXCAVATED AREA TO BE 30-INCHES AND THE FROST DEPTH OUTSIDE OF THIS AREA TO BE 12 TO 18 INCHES. APPARENTLY THE FROZEN SOIL EXPANSION CAUSED THE FAILURE AS THE BREAK ORIGINATED FROM PRESSURE PUSHING DOWNWARD ON THE MAIN.

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

PHMSA standardized cause: OTHER OUTSIDE FORCE DAMAGE — OTHER OUTSIDE FORCE DAMAGE.

PHMSA indexed costs: $130,027 reported total cost, $74,478.59 in 1984 dollars, $154,826.859 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.