Failure Report- Enbridge Energy LP 6/9/09

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) Floodwood, MN to Superior, WI (Unit 3083) Line 2 Crude Oil Leak June 9, 2009 SMART Activity ID 125641 From: James Bunn, Staff Engineer David Barrett, Director – Central Region, PHP-300 To: 1.0 SUMMARY At approximately 5:00 p.m. on June 9, 2009, Enbridge Energy Partners L.P. (“Enbridge”) discovered a crude oil leak on their Line 2 Pipeline in St. Louis County, Gowan, MN (the “Incident”). An estimated 5 barrels (bbls) of crude oil was released from the pipeline. The Incident occurred on the pipeline right of way (ROW) near milepost number 1056 (MP 1056), southeast of the City of Gowan, MN. 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 $44,000. There were no service interruptions or supply impacts as a result of the Incident. 2.0 PIPELINE SYSTEM Enbridge’s Line 2 is a 26-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 line pipe manufactured by A.O. Smith in 1954. The pipeline is 26-inch diameter by 0.281-inch wall thickness, electric flash welded (EFW) type pipe, coated with a coal tar enamel type system. Page | 1#

Page 2The Line 2 maximum operating pressure (MOP) is 651 psig. 3.0 DISCUSSION On June 5, 2009, an Enbridge employee investigating 3rd party activity near MP 1056 discovered a small pool of crude oil on the ROW. Initially, Enbridge attributed the crude oil source to a 3rd party. Enbridge obtained samples of the crude and sent them to a laboratory to identify the source. At 5:35 p.m. on June 9, Enbridge Notified the Minnesota Office of Pipeline Safety (MNOPS) Duty Officer that a leak had occurred. Ron Wiest, MNOPS Senior inspector, conducted an on-site investigation of the Incident. Enbridge proceeded to excavate the area around the pipeline. Once the line was exposed a 30- inch long Plidco split sleeve was discovered at the Incident location. The Plidco sleeve was installed in 1989 to repair a dent in the pipeline. In 1989 Enbridge standard practice for installing Plidco split sleeves on a pipeline called for the replacement of mechanical fasteners (bolts) with bar stock so the two halves of the sleeve could be welded into place. The bar stock was inserted in the flange holes and then welded to the sleeve to secure the sleeve to the pipe line. On June 9, 2009, crude oil was discovered leaking through a ½” long crack in a horizontal seal weld between the Plidco flange body and one of the bar stock filled bolt holes. The Plidco sleeve flanges contained 28 (14 each at 3:00 O’clock and 9:00 O’clock) seal welds. All seal welds were tested in the field for the presence of cracks with magnetic particle inspection (MT). 4.0 EMERGENCY RESPONSE Enbridge employees were dispatched to the Incident site. Once the repair was completed and inspected the contaminated soil was remediated. 5.0 RETURN TO SERVICE After the field investigation was complete, a 2-inch, 3000# socket weld end cap was installed over the leaking seal weld to encapsulate the crack. A second socket weld end cap was installed over a second non-leaking seal weld where MT inspection identified a crack. At the time of the Incident, Line 2 operating pressure was approximately 239 psig. No reduction in operating pressure was required as a result of this incident. Page | 2#

Page 36.0 FINDINGS The Enbridge Line 2 MP 1056 Incident was caused by a crack that initiated on the external surface of a Plidco repair sleeve. The crack was located between the Plidco flange body and one of the bar stock filled bolt holes. The crack was apparently caused by a defective weld. EXHIBITS Information regarding the Incident was reported by Enbridge to the National Response Center (NRC) on June 9, 2009 in NRC Report No. 908091 (Exhibit A), and to the Pipeline and Hazardous Materials Safety Administration (PHMSA) in Accident Report No. 20090191 dated, July 8, 2009 (Exhibit B). Exhibit A Exhibit B NRC Report No. 908091 Accident Report No. 20090191 Page | 3#

Page 4EXHIBIT A NRC REPORT No. 908091#

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 # 908091 INCIDENT DESCRIPTION *Report taken at 17:30 on 09-JUN-09 Incident Type: PIPELINE Incident Cause: EQUIPMENT FAILURE Affected Area: The incident was discovered on 09-JUN-09 at 15:05 local time. Affected Medium: SOIL SOIL ____________________________________________________________________________ SUSPECTED RESPONSIBLE PARTY Organization: ENBRIDGE ENERGY PARTNERS SUPERIOR, WI 54880 Type of Organization: PRIVATE ENTERPRISE ____________________________________________________________________________ INCIDENT LOCATION SEE LEGAL DESCRIPTION County: ST. LOUIS State: MN Section: SE NE 17 Township: 50 N Range: 19 W RURAL AREA ____________________________________________________________________________ RELEASED MATERIAL(S) CHRIS Code: OIL Official Material Name: OIL: CRUDE Also Known As: Qty Released: 5 BARREL(S) ____________________________________________________________________________ DESCRIPTION OF INCIDENT CALLER IS REPORTING A DISCHARGE OF CRUDE OIL FROM A 26 INCH STEEL PIPELINE DUE TO A FITTING THAT WAS LEAKING. CALLER WAS NOTIFIED OF DISCHARGE AT 1505 CDT. ____________________________________________________________________________ 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=908091 10/7/2010#

Page 6Page 2 of 2 Environmental Impact: UNKNOWN Media Interest: NONE Community Impact due to Material: ____________________________________________________________________________ REMEDIAL ACTIONS CALLER STATES THE LINE WAS SHUTDOWN, REPAIRS WILL BE MADE AND THE CONTAMINATED SOIL WILL BE REMOVED. Release Secured: YES Release Rate: Estimated Release Duration: ____________________________________________________________________________ WEATHER Weather: OVERCAST, 55ºF ____________________________________________________________________________ ADDITIONAL AGENCIES NOTIFIED Federal: NONE State/Local: NONE State/Local On Scene: NONE State Agency Number: NONE ____________________________________________________________________________ NOTIFICATIONS BY NRC ATLANTIC STRIKE TEAM (MAIN OFFICE) 09-JUN-09 17:36 USCG ICC (ICC ONI) 09-JUN-09 17:36 DOT CRISIS MANAGEMENT CENTER (MAIN OFFICE) 09-JUN-09 17:36 U.S. EPA V (MAIN OFFICE) 09-JUN-09 17:37 FLD INTEL SUPPORT TEAM DETROIT (COMMAND CENTER) 09-JUN-09 17:36 MN BUREAU OF CRIMINAL APPREHENSION (OPERATIONS CENTER) 09-JUN-09 17:36 MN DEPT OF HEALTH (MAIN OFFICE) 09-JUN-09 17:36 MN U.S. ATTORNEY'S OFFICE (MAIN OFFICE) 09-JUN-09 17:36 NTL ENVMTL EMERG CENTRE CANADA (MAIN OFFICE) 09-JUN-09 17:36 NATIONAL INFRASTRUCTURE COORD CTR (MAIN OFFICE) 09-JUN-09 17:36 NOAA RPTS FOR MN (MAIN OFFICE) 09-JUN-09 17:36 PIPELINE & HAZMAT SAFETY ADMIN (OFFICE OF PIPELINE SAFETY (AUTO)) 09-JUN-09 17:36 WI DEPT NAT RES BUREAU OF LAW ENF (MAIN OFFICE) 09-JUN-09 17:36 USCG DISTRICT 9 (COMMAND CENTER) 09-JUN-09 17:36 ____________________________________________________________________________ ADDITIONAL INFORMATION CALLER WILL NOTIFY STATE AGENCIES. ___________________________________________________________________________ *** END INCIDENT REPORT # 908091 *** http://www.nrc.uscg.mil/reports/rwservlet?standard web+inc _ _ seq=908091 10/7/2010#

Page 7EXHIBIT B ACCIDENT REPORT No. 20090191#

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. M ile 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 fa ilure? 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) Bir ds 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: _________ Groundw ater 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#