PHMSA Report 20120049 - NORTHERN NATURAL GAS CO — Gas transmission and gathering — incident on 2012-04-25 | Regulus

Gas transmission and gathering incident in HINTON, PLYMOUTH County, IA. Reported cause: EXCAVATION DAMAGE. Reported consequences: 0 fatalities, 2 injuries, 46285 NATURAL GAS released, $218,190 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: 20120049.

Operator ID: 13750.

Reported incident date: 4/25/2012 13:45.

Location detail: 20.29

Cause detail: EXCAVATION DAMAGE BY THIRD PARTY

Cause detail: NOTIFICATION ISSUE

Cause detail: NO NOTIFICATION MADE TO THE ONE-CALL CENTER/811

Cause detail: ON APRIL 25, 2012, NORTHERN NATURAL GAS' 24-INCH-DIAMETER SOUTH SIOUX CITY-TO-PAULINA M560C MAINLINE (C-LINE) WAS DAMAGED DURING THE INSTALLATION OF FARM DRAINAGE TILE IN A FIELD IN PLYMOUTH COUNTY NEAR HINTON, IOWA. THE TILING WORK WAS BEING PERFORMED BY DEROCHER CONSTRUCTION HEADQUARTERED IN LE MARS, IOWA, ON BEHALF OF RANDY RIEDIGER OF HINTON, IOWA, THE FARM TENANT. THE DAMAGED C-LINE RUPTURED AND THE ESCAPING GAS IGNITED. TWO TILING WORKERS WERE TREATED FOR INJURIES AT A SIOUX CITY HOSPITAL BUT THEIR INJURIES ARE NOT BELIEVED TO BE LIFE THREATENING. NO ONE CALL REQUEST WAS PLACED FOR THE TILING OPERATION. REPAIRS TO THE C-LINE AND INSPECTION OF THE NEARBY 16-INCH-DIAMETER SOUTH SIOUX CITY-TO-PAULINA B-LINE WERE COMPLETED APRIL 27, 2012. NO CUSTOMERS LOST SERVICE DUE TO THE LINE HIT OR THE SUBSEQUENT INVESTIGATION AND REPAIRS. FACILITY PLANNING ESTIMATES THE TOTAL GAS LOST AS A RESULT OF THIS INCIDENT TO BE 57.576 MMCF. THE IOWA ATTORNEY GENERAL OFFICE CONTACTED NORTHERN NATURAL GAS IMMEDIATELY FOLLOWING THE INCIDENT AND HAS OPENED AN INVESTIGATION INTO THE ONE CALL VIOLATION. SUPPLEMENTAL/FINAL REPORT FOR REPORT NO. 20120049-15515 DATED 05/14/2012. UPDATED INFORMATION IN PART A, SECTION 11, PART D, SECTION 7 WITH ESTIMATED FINAL TOTAL COST. APPROXIMATELY 102 FEET OF NEW 24-INCH-DIAMETER TESTED PIPE WAS REPLACED. THE LEGAL DEPARTMENT OF NORTHERN NATURAL GAS COMPANY IS FOLLOWING UP WITH SEEKING REIMBURSEMENT FOR COST INCURRED FROM THE INCIDENT. SUPPLEMENTAL/FINAL UPDATE TO REPORT # 20120049-15648 - IN SECTION C, ITEM 6 WHERE A MECHANICAL PUNTURE WAS INDICATED, ALTHOUGH THERE EXTENSIVE DAMAGE TO THE PIPE, THE SIZE OF THE PUNTURE IS ESTIMATED AS 10 INCHES AXIAL BY A CIRCUMFERENTIAL SIZE OF 18-INCHES. SUPPLEMENTAL/FINAL: REPORT # 20120049, DATED 5/14/2012 - UPDATED PART D ITEM 7A, PART G3 ITEM 10 TO TRENCHER AND ITEM 16. THE TWO TILING WORKERS INJURIES: ONE INCURRED 1ST DEGREE BURNS ON HIS BACK AND THE OTHER INCURRED 1ST AND 2ND DEGREE BURNS ON HIS BACK.

PHMSA trend classification: significant incident, serious incident.

PHMSA standardized cause: EXCAVATION DAMAGE — THIRD PARTY EXCAVATION DAMAGE.

PHMSA indexed costs: $472,273 reported total cost, $288,077.98 in 1984 dollars, $577,929.677 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.