LACLEDE GAS CO

Incident Narrative

AFTER COMPLETING A LEAK INVESTIGATION FROM A CUSTOMER REPORTED CALL OF A SLIGHT INSIDE ODOR, IT WAS DETERMINED A NEARBY 24 INCH CAST IRON MAIN WAS LEAKING. EXCAVATION CREWS HAD DIFFICULTY REACHING THE MAIN DUE ITS DEPTH OF 84 INCHES ALONG WITH THE CONCRETE AND BRICK FOUND BELOW THE PIPE. TWO LONGITUDINAL CRACKS TOTALING 32 INCHES IN LENGTH WERE FOUND ON THE BOTTOM SECTION OF THE PIPE. INSTALLATION OF A STAINLESS STEEL CLAMP WAS ATTEMPTED TO REPAIR THE LEAK; HOWEVER IT WAS UNSUCCESSFUL. THE INCIDENT WAS DEEMED TO BE REPORTABLE ON FEBRUARY 27, 2016, WHEN IT WAS DETERMINED THAT THE REPAIR COSTS WOULD PROBABLY EXCEED $50,000. THE COMPANY ORDERED A 44 INCH LONG STEEL, SPLIT SLEEVE ENCAPSULATION FITTING AS AN ALTERNATE REPAIR. THE ENCAPSULATION FITTING REQUIRED ADDITIONAL EXCAVATION OF THE PIPE WHICH UNCOVERED A THIRD CRACK 16 INCHES LONG. THE ENCAPSULATION FITTING WAS SUCCESSFULLY INSTALLED AROUND THE ORIGINAL TWO CRACKS. THE THIRD CRACK WAS SOAP TAPED AS A TEMPORARY REPAIR. SERVICE TECHNICIANS REMAINED ONSITE TO MONITOR THE LEAK WHILE THE REPAIRS WERE MADE. IT IS UNCLEAR IF THE PIPE WAS CONSTRUCTED RESTING ON CONCRETE AND BRICK OR IF SUBSIDENCE OVER THE PAST 113 YEARS MOVED THE PIPE TO ITS CURRENT POSITION. THE COMPANY IS ALSO UNABLE TO DETERMINE IF OUTSIDE FORCES FROM THE TRAFFIC ABOVE THE PIPE WAS A CONTRIBUTING FACTOR TO THE FAILURE. THE UNCERTAINTY OF THE ROOT CAUSE OF FAILURE HAS PROMPTED THE COMPANY TO ACCELERATE ITS PLANS FOR FULL REPLACEMENT OF THIS PIPE SEGMENT AND ADJOINING MAIN. THE COMPANY HAS PROPOSED REPLACING OR ABANDONING APPROXIMATELY 2,800 FEET OF THE 24 INCH CAST IRON MAIN INVOLVED AND APPROXIMATELY 900 FEET OF 12 INCH CAST IRON MAIN.