Failure Report-Enbridge Energy LP 11/13/07

Page 1Official PDFMemorandum U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration Central Region Office Office of Pipeline Safety Date: September 30, 2010 Subject: Summary Incident Report Enbridge Energy Partners, L.P. (Op ID 11169) Clearbrook, MN to Deer River, MN (Unit 3083) Line 3 Crude Oil Leak November 13, 2007 SMART Activity ID 124316 From: James Bunn, Staff Engineer To: David Barrett, Director – Central Region, PHP-300 1.0 SUMMARY At approximately 7:00 a.m. on November 13, 2007, crude oil leaked from the Enbridge Energy Partners L.P. (“Enbridge”) Line 3 Pipeline in Clearwater County, Clearbrook, MN (the “Incident”). An estimated 2 barrels (bbls) of crude oil was released from the pipeline. The Incident occurred on the pipeline right of way (ROW) near milepost number 912 (MP 912), approximately three miles southeast of the Enbridge Clearbrook Terminal. No fatalities or injuries occurred as a result of the Incident. The Incident did not occur in a high consequence area (HCA) and no water was impacted. The total cost of the Incident, pipeline repair and environmental cleanup, is estimated at $30,680. There were no service interruptions or supply impacts as a result of the Incident. 2.0 PIPELINE SYSTEM Enbridge’s Line 3 is a 34-inch diameter crude oil pipeline that runs from Gretna, Manitoba, Canada to Superior, WI. At the Incident location, the pipeline is constructed of API 5L X-52 Page | 1#

Page 2line pipe manufactured by U.S. Steel in 1967. The pipeline is 34-inch diameter by 0.344-inch wall thickness, (double submerged arc welded) DSAW type pipe, coated with a tape type system. The line pipe was transported from the pipe mill to the construction site on rail cars. The Line 3 maximum operating pressure (MOP) is 757 psig. 3.0 DISCUSSION An Enbridge employee in route to work discovered a crude oil leak in a ditch on the south side of County Road 3. At 8:22 a.m. Enbridge Notified the Minnesota Office of Pipeline Safety (MNOPS) Duty Officer that a leak had occurred in a pasture on County Road 3, about 3 ½ miles east of Highway 92. Brian Pierzina, MNOPS Senior inspector, conducted an on-site investigation of the Incident. In situ visual inspection of the damaged pipe joint revealed two pin-holes located in the DSAW longitudinal seam. Ultrasonic inspection of the longitudinal seam detected a fatigue crack that initiated on the pipe internal surface at the toe of the DSAW longitudinal seam. This type of defect is very similar to other defects that had been identified by Enbridge on Line 3. In late November 2007, Enbridge ran an in-line inspection (ILI) crack detection (CD) tool from Clearbrook, MN to Superior, WI to determine if the MP 912 fatigue crack could be detected. The ILI tool did not complete the entire assessment from Clearbrook to Superior due to a mechanical failure experienced during the run. However, the MP 912 joint containing the fatigue crack was successfully inspected and the fatigue crack was identified by the ILI tool. On November 28, 2007, Enbridge removed an eleven foot section of pipe at MP 912 that contained the fatigue crack. This section of pipe was transported to a metallurgical laboratory for further analysis. The analysis confirmed that the failure was a fatigue type failure that initiated on the pipe internal surface at the toe of the DSAW longitudinal seam. The fatigue crack was apparently initiated by cyclical loading that occurred during rail transport of the line pipe from the pipe mill to the construction site. Pressure cycling during the operational life of the pipeline caused the fatigue crack to grow to failure. Based on this incident, Enbridge updated their crack management program for Line 3. 4.0 EMERGENCY RESPONSE Enbridge employees were dispatched to the Incident site. 5.0 RETURN TO SERVICE After the field investigation was complete, a four foot long Type B, tight fitting repair sleeve was installed in the area where the Incident occurred. Page | 2#

Page 3At the time of the Incident, Line 3 operating pressure was approximately 337 psig. Enbridge imposed a voluntary pressure reduction on Line 3 at the Clearbrook Terminal discharge. The Clearbrook Terminal maximum discharge pressure was limited to 80% of the maximum discharge pressure experienced within 15 days previous to the Incident, specifically 434 psig. The pipeline was then returned to service at reduced pressure. As of September 30, 2010, the pressure reduction remains in place. 6.0 FINDINGS The Enbridge Line 3 MP 912 Incident was caused by a fatigue crack that initiated on the pipe internal surface at the toe of the DSAW longitudinal seam. The fatigue crack was apparently initiated by cyclic loading that occurred during rail transport of the line pipe from the pipe mill to the construction site and eventually grew to failure from pressure cycling during pipeline operation. EXHIBITS Information regarding the Incident was reported by Enbridge to the National Response Center (NRC) on November 13, 2007 in NRC Report No. 854402 (Exhibit A), and to the Pipeline and Hazardous Materials Safety Administration (PHMSA) in Accident Report No. 20070350 dated December 12, 2007 (Exhibit B). Exhibit A NRC Report No. 854402 Exhibit B Accident Report No. 20070350 Exhibit C Metallurgical Report Page | 3#

Page 4EXHIBIT A NRC REPORT No. 854402#

Page 5Page 1 of 2 NATIONAL RESPONSE CENTER 1-800-424-8802 *** For Public Use *** Information released to a third party shall comply with any applicable federal and/or state Freedom of Information and Privacy Laws Incident Report # 854402 INCIDENT DESCRIPTION *Report taken at 09:33 on 13-NOV-07 Incident Type: PIPELINE Incident Cause: EQUIPMENT FAILURE Affected Area: The incident was discovered on 13-NOV-07 at 07:20 local time. Affected Medium: LAND GROUND ____________________________________________________________________________ SUSPECTED RESPONSIBLE PARTY Organization: ENBRIDGE ENERGY CO. SUPERIOR, WI 54880 Type of Organization: PRIVATE ENTERPRISE ____________________________________________________________________________ INCIDENT LOCATION County: CLEARWATER City: CLEAR BROOK State: MN Section: 3 Township: 148N Range: 37W NEAR COUNTY 3 ____________________________________________________________________________ RELEASED MATERIAL(S) CHRIS Code: OIL Official Material Name: OIL: CRUDE Also Known As: Qty Released: 2 BARREL(S) ________________________________________________________________________ DESCRIPTION OF INCIDENT CALLER IS REPORTING THAT 2 BARRELS OF CRUDE OIL RELEASED FROM A PIPELINE ONTO THE GROUND DUE TO A LEAKING PIPELINE. ____________________________________________________________________________ INCIDENT DETAILS Pipeline Type: TRANSMISSION DOT Regulated: YES Pipeline Above/Below Ground: BELOW Exposed or Under Water: NO Pipeline Covered: UNKNOWN ____________________________________________________________________________ DAMAGES Fire Involved: NO Fire Extinguished: UNKNOWN INJURIES: NO Hospitalized: Empl/Crew: Passenger: FATALITIES: NO Empl/Crew: Passenger: Occupant: EVACUATIONS: NO Who Evacuated: Radius/Area: Damages: NO Closure Type Air: N Length of Direction of Description of Closure Closure Closure Road: N Waterway: N Track: N Passengers Transferred: NO Major Artery: N http://www.nrc.uscg.mil/reports/rwservlet?standard web+inc _ _ seq=854402 11/15/2010#

Page 6Page 2 of 2 Environmental Impact: UNKNOWN Media Interest: NONE Community Impact due to Material: ____________________________________________________________________________ REMEDIAL ACTIONS PIPELINE MAINTENANCE CREWS WERE DISPATCHED TO THE SITE, PADS WERE PUT DOWN ON THE AREA AND LINES WERE CLOSED Release Secured: YES Release Rate: Estimated Release Duration: ____________________________________________________________________________ WEATHER Weather: UNKNOWN, ºF ____________________________________________________________________________ ADDITIONAL AGENCIES NOTIFIED Federal: NONE State/Local: LOCAL SHERIFF'S OFFICE State/Local On Scene: State Agency Number: NO REPORT # ____________________________________________________________________________ NOTIFICATIONS BY NRC ATLANTIC STRIKE TEAM (MAIN OFFICE) 13-NOV-07 09:38 USCG ICC (ICC ONI) 13-NOV-07 09:38 DOT CRISIS MANAGEMENT CENTER (MAIN OFFICE) 13-NOV-07 09:38 U.S. EPA V (MAIN OFFICE) 13-NOV-07 09:40 MN DEPT OF HEALTH (MAIN OFFICE) 13-NOV-07 09:38 MN U.S. ATTORNEY'S OFFICE (ATTN: CARL WAHL) 13-NOV-07 09:38 NATIONAL INFRASTRUCTURE COORD CTR (MAIN OFFICE) 13-NOV-07 09:38 NOAA RPTS FOR MN (MAIN OFFICE) 13-NOV-07 09:38 PIPELINE & HAZMAT SAFETY ADMIN (OFFICE OF PIPELINE SAFETY (AUTO)) 13-NOV-07 09:38 MN DEM ATTN: MS. GOELZ (MAIN OFFICE) 13-NOV-07 09:38 SURFACE TRANS SECURITY INSPECT PROG (COMMAND CENTER) 13-NOV-07 09:38 ____________________________________________________________________________ ADDITIONAL INFORMATION CALLER HAD NO FURTHER INFORMATION. ___________________________________________________________________________ *** END INCIDENT REPORT # 854402 *** http://www.nrc.uscg.mil/reports/rwservlet?standard web+inc _ _ seq=854402 11/15/2010#

Page 7EXHIBIT B ACCIDENT REPORT No. 20070350#

Page 8NOTICE: This report is required by 49 CFR Part 195. Failure to report can result in a civil penalty not to exceed $25,000 for each violation for each day that such violation persists except that the maximum civil penalty shall not exceed $500,000 as provided in 49 USC 60122 Form Approved OMB No. 2137-0047 U.S. Department of Transportation Research and Special Programs Administration ACCIDENT REPORT – HAZARDOUS LIQUID PIPELINE SYSTEMS Report Date No. (DOT Use Only) INSTRUCTIONS Important: Please read the separate instructions for completing this form before you begin. They clarify the information requested and provide specific examples. If you do not have a copy of the instructions, you can obtain one from the Office Of Pipeline Safety Web Page at http://ops.dot.gov. PART A – GENERAL REPORT INFORMATION Original Report Supplemental Report Final Report 1. a. Operator's OPS 5-digit Identification Number (if known) / ____________/ 2. b. If Operator does not own the pipeline, enter Owner’s OPS 5-digit Identification Number (if known) / ___ / c. Name of Operator ______________________________________________________________________________________ d. Operator street address _______________________________________________________________________________ e. Operator address ______________________________________________________________________________________ City, County, State and Zip Code IMPORTANT: IF THE SPILL IS SMALL, THAT IS, THE AMOUNT IS AT LEAST 5 GALLONS BUT IS LESS THAN 5 BARRELS, COMPLETE THIS PAGE ONLY, UNLESS THE SPILL IS TO WATER AS DESCRIBED IN 49 CFR §195.52(A)(4) OR IS OTHERWISE REPORTABLE UNDER §195.50 AS REVISED IN CY 2001. 2. Time and date of the accident / / / / / / / / hr. month day year 3. Location of accident (If offshore, do not complete a through d. See Part C.1) a. Latitude: _____ Longitude: __________ (if not available, see instructions for how to provide specific location) b. _________________________________________________ City, and County or Parish c. _________________________________________________ State and Zip Code d. Mile post/valve station or survey station no. (whichever gives more accurate location) _________________________________ 4. Telephone report / / / / / / / / NRC Report Number month day year 5. Losses (Estimated) Public/Community Losses reimbursed by operator: Public/private property damage $_______________ Cost of emergency response phase $_______________ Cost of environmental remediation $_______________ Other Costs $_______________ (describe) _____________________________________ Operator Losses: Value of product lost $_______________ Value of operator property damage $_______________ Other Costs $_______________ (describe) _____________________________________ Total Costs $_______________ 6. Commodity Spilled Yes No (If Yes, complete Parts a through c where applicable) a. Name of commodity spilled ___________________________ b. Classification of commodity spilled: HVLs /other flammable or toxic fluid which is a gas at ambient conditions CO2 or other non-flammable, non-toxic fluid which is a gas at ambient conditions Gasoline, diesel, fuel oil or other petroleum product which is a liquid at ambient conditions Crude oil c. Estimated amount of commodity involved : Barrels Gallons (check only if spill is less than one barrel) Amounts: Spilled : ____________ Recovered: ____________ CAUSES FOR SMALL SPILLS ONLY (5 gallons to under 5 barrels) : (For large spills [5 barrels or greater] see Part H) Corrosion Natural Forces Excavation Damage Other Outside Force Damage Material and/or Weld Failures Equipment Incorrect Operation Other PART B – PREPARER AND AUTHORIZED SIGNATURE (type or print) Preparer's Name and Title Preparer's E-mail Address Area Code and Telephone Number Area Code and Facsimile Number Authorized Signature (type or print) Name and Title Date Area Code and Telephone Number Form RSPA F 7000-1 ( 01-2001 ) Page 1 of 4 OPS Data Facsimile#

Page 9PART C – ORIGIN OF THE ACCIDENT (Check all that apply) 1. Additional location information a. Line segment name or ID _______________________ b. Accident on Federal land other than Outer Continental Shelf Yes No c. Is pipeline interstate? Yes No Offshore: Yes No (complete d if offshore) d. Area ___________________ Block # ______________ State / / or Outer Continental Shelf 2. Location of system involved (check all that apply) Operator’s Property Pipeline Right of Way High Consequence Area (HCA)? Describe HCA____________________________________ 3. Part of system involved in accident Above Ground Storage Tank Cavern or other below ground storage facility Pump/meter station; terminal/tank farm piping and equipment, including sumps Other Specify: _________________________________ Onshore pipeline, including valve sites Offshore pipeline, including platforms If failure occurred on Pipeline, complete items a - g: 4. Failure occurred on Body of Pipe Pipe Seam Scraper Trap Pump Sump Joint Component Valve Metering Facility Repair Sleeve Welded Fitting Bolted Fitting Girth Weld Other (specify) Year the component that failed was installed: / / 5. Maximum operating pressure (MOP) a. Estimated pressure at point and time of accident: ____ PSIG b. MOP at time of accident: ___________PSIG c. Did an overpressurization occur relating to the accident? Yes No a. Type of leak or rupture Leak: Pinhole Connection Failure (complete sec. H5) Puncture, diameter (inches) _________ Rupture: Circumferential – Separation Longitudinal – Tear/Crack, length (inches) __________ Propagation Length, total, both sides (feet) _________ N/A Other _______________________________ b.Type of block valve used for isolation of immediate section: Upstream: Manual Automatic Remote Control Check Valve Downstream: Manual Automatic Remote Control Check Valve c. Length of segment isolated _______ ft d. Distance between valves _______ ft e. Is segment configured for internal inspection tools? Yes No f. Had there been an in-line inspection device run at the point of failure? Yes No Don’t Know Not Possible due to physical constraints in the system g. If Yes, type of device run (check all that apply) High Resolution Magnetic Flux tool Year run: ______ Low Resolution Magnetic Flux tool Year run: ______ UT tool Year run: ______ Geometry tool Year run: ______ Caliper tool Year run: ______ Crack tool Year run: ______ Hard Spot tool Year run: ______ Other tool Year run: ______ PART D – MATERIAL SPECIFICATION PART E – ENVIRONMENT 1. Nominal pipe size (NPS) / / in. 2. Wall thickness / / in. 3. Specification SMYS / / 4. Seam type 5. Valve type 6. Manufactured by in year / / 1. Area of accident In open ditch Under pavement Above ground Underground Under water Inside/under building Other ____________ 2. Depth of cover: inches PART F – CONSEQUENCES 1. Consequences (check and complete all that apply) a. Fatalities Injuries c. Product ignited Yes No d. Explosion Yes No Number of operator employees: _______ _______ e. Evacuation (general public only) / / people Contractor employees working for operator: _______ _______ Reason for Evacuation: General public: _______ _______ Precautionary by company Totals: _______ _______ Evacuation required or initiated by public official b. Was pipeline/segment shutdown due to leak? Yes No f. Elapsed time until area was made safe: If Yes, how long? ______ days ______ hours _____ minutes / / hr. / / min. 2. Environmental Impact a. Wildlife Impact: Fish/aquatic Yes No e. Water Contamination: Yes No (If Yes, provide the following) Birds Yes No Amount in water _________ barrels Terrestrial Yes No Ocean/Seawater No Yes b. Soil Contamination Yes No Surface No Yes If Yes, estimated number of cubic yards: _________ Groundwater No Yes c. Long term impact assessment performed: Yes No Drinking water No Yes (If Yes, check below.) d. Anticipated remediation Yes No Private well Public water intake If Yes, check all that apply: Surface water Groundwater Soil Vegetation Wildlife Form RSPA F 7000-1 ( 01-2001 ) OPS Data Facsimile Page 2 of 4#

Page 10PART G – LEAK DETECTION INFORMATION 1. Computer based leak detection capability in place? 2. Was the release initially detected by? (check one): Yes No CPM/SCADA-based system with leak detection Static shut-in test or other pressure or leak test Local operating personnel, procedures or equipment Remote operating personnel, including controllers Air patrol or ground surveillance A third party Other (specify) _________________ 3. Estimated leak duration days ____ hours ____ PART H – APPARENT CAUSE Important: There are 25 numbered causes in this Part H. Check the box corresponding to the primary cause of the accident. Check one circle in each of the supplemental categories corresponding to the cause you indicate. See the instructions for guidance. H1 – CORROSION 1. External Corrosion 2. Internal Corrosion (Complete items a – e where applicable.) b. Visual Examination Localized Pitting General Corrosion Other ____________________ a. Pipe Coating c. Cause of Corrosion Bare Galvanic Atmospheric Coated Stray Current Microbiological Cathodic Protection Disrupted Stress Corrosion Cracking Selective Seam Corrosion Other ____________________ d. Was corroded part of pipeline considered to be under cathodic protection prior to discovering accident? No Yes, Year Protection Started: / / e. Was pipe previously damaged in the area of corrosion? No Yes => Estimated time prior to accident: / / years / / months Unknown H2 – NATURAL FORCES 3. Earth Movement => Earthquake Subsidence Landslide Other 4. Lightning 5. Heavy Rains/Floods => Washouts Flotation Mudslide Scouring Other 6. Temperature => Thermal stress Frost heave Frozen components Other 7. High Winds H3 – EXCAVATION DAMAGE 8. Operator Excavation Damage (including their contractors/Not Third Party) 9. Third Party (complete a-f) a. Excavator group General Public Government Excavator other than Operator/subcontractor b. Type: Road Work Pipeline Water Electric Sewer Phone/Cable Landowner-not farming related Farming Railroad Other liquid or gas transmission pipeline operator or their contractor Nautical Operations Other ________ c. Excavation was: Open Trench Sub-strata (boring, directional drilling, etc…) d. Excavation was an ongoing activity (Month or longer) Yes No e. Did operator get prior notification of excavation activity? If Yes, Date of last contact /_________/ Yes; Date received: / / mo. / / day / ______/ yr. No Notification received from: One Call System Excavator Contractor Landowner f. Was pipeline marked as result of location request for excavation? No i. Temporary markings: Flags Stakes Paint ii. Permanent markings: iii. Marks were (check one) : Accurate Not Accurate iv. Were marks made within required time? Yes No H4 – OTHER OUTSIDE FORCE DAMAGE 10. Fire/Explosion as primary cause of failure => Fire/Explosion cause: Man made Natural 11. Car, truck or other vehicle not relating to excavation activity damaging pipe 12. Rupture of Previously Damaged Pipe 13. Vandalism Yes (If Yes, check applicable items i - iv) Form RSPA F 7000-1 ( 01-2001 ) Page 3 of 4 OPS Data Facsimile#

Page 11H5 – MATERIAL AND/OR WELD FAILURES Material 14. Body of Pipe => Dent Gouge Bend Arc Burn Other 15. Component => Valve Fitting Vessel Extruded Outlet Other 16. Joint => Gasket O-Ring Threads Other Weld 17. Butt => Pipe Fabrication Other 18. Fillet => Branch Hot Tap Fitting Repair Sleeve Other 19. Pipe Seam => LF ERW DSAW Seamless Flash Weld HF ERW SAW Spiral Other Complete a-g if you indicate any cause in part H5. a. Type of failure: Construction Defect => Poor Workmanship Procedure not followed Poor Construction Procedures Material Defect b. Was failure due to pipe damage sustained in transportation to the construction or fabrication site? Yes No c. Was part which leaked pressure tested before accident occurred? Yes, complete d-g No d. Date of test: / / yr. / / mo. / / day e. Test medium: Water Inert Gas Other f. Time held at test pressure: / / hr. g. Estimated test pressure at point of accident: PSIG H6 – EQUIPMENT 20. Malfunction of Control/Relief Equipment => Control valve Instrumentation SCADA Communications Block valve Relief valve Power failure Other 21. Threads Stripped, Broken Pipe Coupling => Nipples Valve Threads Dresser Couplings Other 22. Seal Failure => Gasket O-Ring Seal/Pump Packing Other H7 – INCORRECT OPERATION 23. Incorrect Operation a. Type: Inadequate Procedures Inadequate Safety Practices Failure to Follow Procedures Other _______________________________________ b. Number of employees involved who failed a post-accident test: drug test: / / alcohol test /_________/ H8 – OTHER 24. Miscellaneous, describe: 25. Unknown Investigation Complete Still Under Investigation (submit a supplemental report when investigation is complete) PART I – NARRATIVE DESCRIPTION OF FACTORS CONTRIBUTING TO THE EVENT (Attach additional sheets as necessary) Form RSPA F 7000-1 (01-2001 ) Page 4 of 4 OPS Data Facsimile#

Page 12EXHIBIT C METALLURGICAL REPORT No distribution without permission from the client#

Page 13Metallurgical Analysis of November 13, 2007 Leak on Line 3 at US MP 912.3188 Enbridge Energy Partners, L.P. Final Report – 813 7608 1 May 22, 2008 .#