AMEREN ILLINOIS COMPANY

Incident Narrative

A 1/2"" PLASTIC GAS SERVICE TO 419 N WEST STREET WAS CUT BY A THIRD PARTY CONTRACTOR, RESULTING IN GAS BLOWING TO ATMOSPHERE. THE AMEREN ILLINOIS FIRST RESPONDER STOPPED THE BLOWING GAS USING AN EXPANDABLE PLUG INTO THE CUT 1/2"" SERVICE. APPROXIMATELY 80 MINUTES LATER, AFTER THE CUT GAS SERVICE HAD BEEN PLUGGED AND AN AMEREN ILLINOIS CREW WAS ON SITE TO MAKE REPAIRS, AN EXPLOSION OCCURRED AT THE STRUCTURE LOCATED AT 430 N WEST STREET. THE POST INVESTIGATION OF THE AREA REQUIRED A TEMPORARY OUTAGE TO 33 GAS CUSTOMERS. REVISION AS OF (12/20/2016): THE LIKELY CAUSE OF THE INCIDENT, GIVEN THE RELATIVELY SHORT TIMEFRAME BETWEEN THE DAMAGED GAS SERVICE AT 419 N WEST ST AND THE INCIDENT OCCURRING AT 430 N WEST ST, IS ATTRIBUTED TO THE THIRD PARTY DAMAGE OF THE GAS SERVICE. THE CONTRACTOR INSTALLING A WATER MAIN IN THE STREET HAD A VALID DIG TICKET, BUT THE SERVICE WAS INACCURATELY MARKED INACCURATELY MARKED IN THE FIELD BY THE LOCATOR. ADDITIONAL POST-INCIDENT INVESTIGATION AT THE 430 N WEST STREET LOCATION DETERMINED THAT THE SEWER TRAP FOR THE SEWER LATERAL INTO THE STRUCTURE WAS DRY. AMEREN ILLINOIS, HOWEVER, WAS NOT ABLE TO ESTABLISH THAT NATURAL GAS FROM THE HIT SERVICE LOCATION MIGRATED INTO THE HOME AT 430 N WEST ST. PART A, LINE 10 - LOST GAS ESTIMATE WAS UPDATED TO 5.4 MCF, WITH AN ASSOCIATED LOST GAS COST OF $21 UPDATED IN PART D. PART A, LINE 12 - THERE WERE TWO INJURIES REPORTED, HOWEVER AMEREN ILLINOIS COULD ONLY CONFIRM THAT ONE REQUIRED INPATIENT HOSPITALIZATION. PART A, LINE 13 - THE GAS MAIN WAS SHUT DOWN AFTER THE INCIDENT OCCURRED. THE AMEREN ILLINOIS FIRST RESPONDER HAD REMOVED THE PLUG STOPPER AFTER THE INCIDENT, AND THEN THE ADJACENT 1-1/4"" PLASTIC GAS MAIN WAS EXCAVATED AND SQUEEZED OFF INTERRUPTING SERVICE TO THE 400 BLOCK OF N WEST ST. THE GAS MAIN SERVING THE 200 AND 300 BLOCK OF N WEST ST WAS ALSO TAKEN OUT OF SERVICE AS A PRECAUTIONARY MEASURE. THE GAS MAINS WERE REENERGIZED UPON COMPLETION OF AIR PRESSURE TESTING OF THE GAS FACILITIES IN THE 200 - 400 BLOCK OF N WEST ST. PART G - THE PRIMARY CAUSE OF THE INCIDENT WAS UPDATED TO G3, THIRD PARTY DAMAGE, WITH ADDITIONAL SUPPORTING INFORMATION PROVIDED. REVISION AS OF 12/31/2016 PART A, LINE 13B - CLARIFYING THE TIME RESTORATION TO GAS MAINS IS CORRECTLY STATED AS 5/13/2016 00:00, WHICH WAS RIGHT AT MIDNIGHT. PART A, LINE 14 - REVISED TO ""YES"" PART C, LINE 5 - REVISED TO ""MECHANICAL"", WITH DIMENSIONS INTENDED TO SHOW THE CIRCUMFERENCE OF THE CUT 1/2"" SERVICE..