PEOPLES GAS LIGHT & COKE CO — Gas transmission and gathering — incident on 2011-12-01

Gas transmission and gathering incident in CHICAGO, COOK County, IL. Reported cause: EXCAVATION DAMAGE. Reported consequences: 0 fatalities, 0 injuries, 1750 NATURAL GAS released, $65,000 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: 20120038.

Operator ID: 15329.

Reported incident date: 12/1/2011 14:30.

Location detail: 90+70.2

Cause detail: EXCAVATION DAMAGE BY OPERATOR'S CONTRACTOR (SECOND PARTY)

Cause detail: LOCATING ISSUE

Cause detail: FACILITY NOT MARKED DUE TO INCORRECT FACILITY RECORDS/MAPS

Cause detail: WHILE PERFORMING INTEGRITY MANAGEMENT ASSESSMENT WORK ON A 36" DIAMETER TRANSMISSION LINE, AN UNMARKED AND UNMAPPED 2" DIAMETER SERVICE LINE STUB WAS DAMAGED BY EXCAVATION EQUIPMENT RESULTING IN RELEASE OF GAS ON THE 2" STUB. THE INCIDENT IMPACTED MORE THAN THE 2" SERVICE LINE. THE 2" TAP ON THE 36" TRANSMISSION LINE WAS IMPACTED, AND THE OPERATING PRESSURE OF THE TRANSMISSION LINE HAD TO BE REDUCED, AND A PORTION TAKEN OUT OF SERVICE TO REPLACE A SECTION OF THE 36" TRANSMISSION LINE. THIS INCIDENT REPORT WAS ORIGINALLY FILED AS A DISTRIBUTION INCIDENT UNDER REPORT # 20110400-15372 FILED ON 12/22/2011. DETREMINATION WAS MADE TO REFILE THIS INCIDENT AS A TRANSMISSION LINE INCIDENT REPORT FOR THE RECORD. A REQUEST FOR RETRACTION OF THE DISTRIBUTION INCIDENT REPORT WILL BE SENT TO PHMSA. DECEMBER 16, 2015 UPDATE: AT THE REQUEST OF PHMSA, PGL HAS AGAIN LOOKED INTO IDENTIFYING THE YEAR THAT THE ITEM INVOLVED IN THE INCIDENT WAS INSTALLED. THE EXACT YEAR THAT THE 2" DIAMETER SERVICE LINE WAS INSTALLED COULD NOT BE DETERMINED SO IS HAS BEEN MARKED AS "UNKNOWN" IN THE FORM.

PHMSA trend classification: significant incident, not serious.

PHMSA standardized cause: EXCAVATION DAMAGE — OPERATOR/CONTRACTOR EXCAVATION DAMAGE.

PHMSA indexed costs: $111,279 reported total cost, $61,053.036 in 1984 dollars, $143,182.202 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.