Failure Report- Columbia Gas Transmission 5/7/09

Page 1Official PDFFailure Investigation Report – Columbia Head Gasket Failure – Activity ID 130195 Principal Investigator David Hippchen WV PSC Regional Director Byron Coy Date of Report 03/02/2011 Subject Failure Investigation Report – Columbia Clendenin Compressor Station Head Gasket Failure Summary: On May 7, 2009, a head end gasket failed on Clendenin Compressor Station Unit #3, resulting in an uncontrolled gas discharge into the building. The fixed gas detectors actuated the visual alarm which caused the station operator on duty to assess and react to the situation from outside the building. After assessing the situation, the station operator notified gas control and manually initiated a station shutdown. During the emergency shutdown sequence, 3 of 6 fire gates failed in service, allowing gas to vent from the blowdown valves for about 90 minutes until the last fire gate was manually closed. The event was reported as an incident due to the volume of lost gas and associated costs. No injuries were sustained by operator personnel or the public. Operator, Location, & Consequences Date & Time of Failure: 5/7/2009 Commodity Released: Natural Gas City/County & State: Clendenin, Hampshire County, WV OpID & Operator Name 2616 Columbia Gas Transmission Unit # & Unit Name 67791 Clendenin Compressor SMART Activity #: 130195 Milepost / Location Latitude: 38°29'43"N Longitude: 81°18'44"W Type of Failure: Head Gasket Failure and non-operational shutdown valves Fatalities: 0 Injuries 0 Description of area impacted Rural Property damage $726,553 System Details Unit No. 3, Clendenin Compressor Station Events Leading up to the Failure On Thursday, May 7, 2009, the station was set up for a typical pumping Tennessee suction to Coco storage with overflow to TM-17. At approximately 8:42 p.m. a head-end head gasket failed on main unit #3 and the building began filling with gas. As the station operator was preparing for 9:00 p.m. rounds he heard gas blowing, donned safety gear and went to identify the source. He noted that the red strobe light was on at compressor building 3-4, indicating the presence of gas in the building. Cautiously approaching an open door he saw and heard gas blowing CGT GT WV 508 2009-05-07.docx Page 1 of 3#

Page 2Failure Investigation Report – Columbia Head Gasket Failure – Activity ID 130195 between units 3 and 4, but was unable to determine its source. He then returned to the control room to advise Gas Control of the issue and notify them he would shutdown the station. Emergency Response Assistance arrived as a result of telephone notification, but also due to the enormity of noise resulting from the gas blowing off - which could be heard as far as the town of Clendenin. Station Team Leaders, repairmen and an off- duty operator responded. The team was able to identify blow off at the northeast side of the station (a 6" blow off valve at fire gate TM-171l 00) a 4"unit blow down valve in the station and a 6" blow off valve at fire gate TM- LOOPIl08 were blowing. It was then determined the 6" blow off valve at fire gate TM-LOOPIl08 required the most immediate assistance. It was closed to eliminate noise in the immediate vicinity. By this time approximately 45 minutes had elapsed since the initiation of the Emergency shutdown. The team then began determining which valves ahead of the station could be closed to deter the blow off and isolate the station, and they began manually closing line and station valves. It came down to fire gate TM-LOOPlllO to isolate the station, taking nearly 45 minutes to close this valve. At approximately 10:15 p.m. the last fire gate valve was closed and the station finally blew down. Summary of initial start-up plan and return-to-service, including preliminary safety measures While the unit was down, additional investigation and preventative maintenance was performed on the unit. In the investigation, a number of additional anomalies were noted below. After the station was back on line, gas was re-introduced to the pipeline facilities in the compressor building to determine where the leak was coming from. 1. A bent rod was found on compressor 2. 2. Evidence of elevated bearing temperature on compressor 4. 3. Significant rod packing leakage on all the compressors Investigation Findings & Contributing Factors A root cause analysis of this incident has not identified the exact cause of the gasket failure; however the evidence is strong in favor of fluids ingested into the compressor. When gas was re-introduced to the facilities in the building, the head-end of compressor 3 on Unit #3 was quickly identified as the leak source. Upon closer inspection of the compressor unit 3, it was determined that the gas leak was a result of the head end gasket located between the cylinder head and cylinder body being blown out. The blow out was at the six-o’clock discharge valve position on the head end of the cylinder. The blown out portion of the gasket was not recovered. The main causal factor for the Emergency Shutdown Failure was water in the plant Emergency Shutdown air system. The water had worked its way to the low places of the dead end piping that is inherent in the Emergency Shutdown system. The causal factor for the water in the air lines is the extended down time on the plant air dryer. Through this investigation, the exact cause of the gasket failure was not determined. However, it is likely that the failure of the head-end gasket was the result of one or more of the following: • Inadequate torque on one or more of either the through studs or internal studs (or both) in the cylinder, in the vicinity of the leak. No physical evidence was discovered to conclusively rule this in or out. • Imperfection or damage to the gasket material in the area of the failure. • Excessive discharge pressure in cylinder passages due to the clearances being consumed by fluids in the compression chamber and valve pockets. CGT GT WV 508 2009-05-07.docx Page 2 of 3#

Page 3Failure Investigation Report – Columbia Head Gasket Failure – Activity ID 130195 Appendices 1 Root Cause Analysis - Lost Gas 2 Root Cause Analysis - Unit 3 Gasket 3 Response to Data Request 4 OQ Documentation 5 NRC Report #904943 6 Incident report 20090055-6145 7 Maps CGT GT WV 508 2009-05-07.docx Page 3 of 3#

Page 4Appendix 1 Root Cause Analysis – Lost Gas Columbia Gas Transmission Root Cause Investigation This document is on file at PHMSA#

Page 5Appendix 2 Root Cause Analysis – Unit 3 Gasket Columbia Gas Transmission Root Cause Investigation This document is on file at PHMSA#

Page 6130195 Appendix 3 - Response to Data Request Columbia Gas Transmission 1700 MacCorkle Avenue, SE Charleston, WV 25314 Direct: (304) 357-3728 Fax: (304) 357-3804 ghamaty@nisource.com Via: E-Mail George Hamaty Engineer David Hippchen Public Service Commission of West Virginia 201 Brooks Street Charleston, WV 25301 July 20, 2009 RE: Clendenin CS Incident First Data Response Dear Mr. Hippchen: Columbia Gas Transmission (Columbia) respectfully submits the following response to your data request regarding the Emergency Shutdown System (ESD) incident that took place on May 7, 2009 at the Clendenin Compressor Station. 1) Compressor station Operator’s full name and Operator Qualification records. Bradley Williams. (OQ report attached). 2) Procedure to maintain plant ‘Air System’, and if any Service Bulletins were issued by the manufacturer pertaining the Air System (if applicable). No procedure is available to maintain the Air System in Clendenin CS. No Service bulletins were issued. 3) Procedure covering the ESD of the compressor station. Clendenin CS does not have a "site specific" plan for ESD testing, however Company personnel follow the company approved ESD test procedure. 4) When was the last ESD run performed at the CS, (Full Scale or Block Vents)? A blocked vents test was performed on May 1, 2009. 1 of 3#

Page 7130195 Appendix 3 - Response to Data Request 5) Which valves were closed to isolate the compressor station? Please provide the location, equipment number and manufacturer. Please refer to the diagram in Exhibit 1 which displays the location of isolation valves involved in this event. The following listing represents the name and location of the isolation valves. Rockwell SM-101 24”, TM-7; 20”, TM-7 Loop; 20”, Panther Mountain; 20”, Tennessee; 24” on the west end of the station, TM-17; 24” on the east end of the station. 6) In reference to paragraph under ‘Others’ found on page 4 in the Compressor Station Root Cause Analysis, provide additional explanation regarding the AC/DC isolation and how the Telemetry will function after an isolation to its bus takes place in an ESD activation? To be provided at a later stage. 7) Is the low voltage system tied-in to Clendenin’s ESD system and is this typical Columbia standard installation or it applies to Clendenin only? To be provided at a later stage. 8) When was the failed gasket replaced and due to what? Who is the manufacturer? Was it subject to a similar failure, or a different reason (routine PM, an Advisory Bulletin, SB, etc.)? If it failed due to same gasket as in May 2009 incident, was there any RCA generated for the previous gasket? The failed gasket was replaced after the investigation was completed. A similar failure occurred in 2007. No Service Bulletins were issued by the manufacturer in reference to this type of gasket failures. (The RCA for the gasket is attached.) 2 2 of 3#

Page 8130195 Appendix 3 - Response to Data Request Exhibit 1 Schematic drawing (last page in Clendenin Compressor Station ESD Failure/Lost Gas Issue, May 209 Root Cause Analysis) showing the location of the isolation valves that are used in the ESD system at Clendenin CS. 3 3 of 3#

Page 9130195 Appendix 4 - OQ Documentation OPQUALE- OpQual by Team Leader and Employee Employee: BAWILLIAMS Employee Name: Williams,Bradley Team Leader: SNELSON Date Issued Qualification Description ExpirationDate Team Leader PLOQ.0015 4/11/07 SNELSON Isolate & Purge Compressor Units 4/9/12 PLOQ.0019 4/11/07 SNELSON Perform Manual Start/Operate/Stop Compressor Unit 4/9/12 PLOQ.0020 4/11/07 SNELSON Perform Automatic Start/Operate/Stop Compressor Unit 4/9/12 PLOQ.0024 3/6/07 SNELSON Operate Valve 3/4/12 PLOQ.0025 3/6/07 SNELSON Inspect Valve 3/4/12 PLOQ.0029 3/14/02 SNELSON Patrol Pipeline Facilities 3/13/07 PLOQ.0030 3/6/07 SNELSON Operate Portable Gas Detectors - Presence of Gas 3/4/12 PLOQ.0031 3/6/07 SNELSON Operate Portable Gas Detector - % of Gas 3/4/12 PLOQ.0034 3/6/07 SNELSON Purge Gas Facility of Air Using Gas 3/4/12 PLOQ.0035 3/6/07 SNELSON Blowdown Gas Facilities (for Pressure Removal Only) 3/4/12 PLOQ.0036 3/6/07 SNELSON Evacuate Gas from Facilities (for Construction Activities) 3/4/12 OPQUALE- This report pulls all Operator Qualifications for the selected Team Leader (or all) and Employee (or all). 1 of 1 7/1/2009 OPQUALE- OpQual by Team Leader and Employee 1#

Page 10TeleDetail 130195 Appendix 5 - NRC Report 904943 HMIS->INCiDENTs->TELEPhONiCs (Version 3.4.05 PROD ) Rules of Behavior Home Logout Menu [Return to Search] 1..1 of 1 Rescinded Comments (max 250 characters) NRC Number: 904943 Call Date: 05/07/2009Call Time: 22:24:58 Caller Information First Name: Last Name: Company Name: Address: City: State: Country: Zip: Phone 1: Phone 2: Organization Type: Is caller the spiller? Yes No No Response Confidential: Yes No No Response Discharger Information First Name: Last Name: Company Name: Address: City: State: Country: Zip: Phone 1: Phone 2: Organization Type: Spill Information State: County: Nearest City: Zip Code: Location Spill Date: (mm/dd/yyyy) Spill Time: (24hh:mm:ss) DTG Type: DISCOVERED Incident Type FIXED FACILITY Reported Incident Type Description 1 of 2 https://phmhqnwas003/...d=%3d&reportingCompany=&operreportingCompany=%3d&responsibleCompany=&OperresponsibleCompany=%3d&startno=1[10/19/2010 10:51:25 AM]#

Page 11TeleDetail 130195 Appendix 5 - NRC Report 904943 Materials Involved Material / Chris Name Chris Code Total Qty. Water Qty. NATURAL GAS ONG 0 UNKNOWN AMOUNT Medium Type: AIR Additional Medium Information: Injuries: Fatalites: Evacuations: Yes No Unknown No. of Evacuations: Damages: Yes No Unknown Damage Amount: Federal Agency Notified: Yes No Unknown State Agency Notified: Yes No Unknown Other Agency Notified: Yes No Unknown Remedial Actions Additional Info Latitude Degrees: Minutes: Seconds: Quadrant: Longitude Degrees: Minutes: Seconds: Quadrant: Distance from City: Direction: Section: Township: Range: Milepost: 2 of 2 https://phmhqnwas003/...d=%3d&reportingCompany=&operreportingCompany=%3d&responsibleCompany=&OperresponsibleCompany=%3d&startno=1[10/19/2010 10:51:25 AM]#

Page 12130195 Appendix 6 - Incident report 20090055-6145 NOTICE: This report is required by 49 CFR Part 191. Failure to report can result in a civil penalty not to exceed $25,000 for each violation Form Approved for each day that such violation persists except that the maximum civil penalty shall not exceed $500,000 as provided in 49 USC 1678. OMB No. 2137-0522 U.S. Department of Transportation Research and Special Programs Administration INCIDENT REPORT - GAS TRANSMISSION AND GATHERING 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 Nearest street or road City and County or Parrish a. b. c. State and Zip Code d. Mile Post/Valve Station e. Survey Station No. f. Latitude: Longitude: (if not available, see instructions for how to provide specific location) g. Class location description Onshore: Class 1 Class 2 Class 3 Class 4 Offshore: Class 1 (complete rest of this item) Area ___________________ Block # ___________ State / / or Outer Continental Shelf h. Incident on Federal Land other than Outer Continental Shelf Yes No i. Is pipeline Interstate Yes No 4. Type of leak or rupture Leak: Pinhole Connection Failure (complete sec. F5) Puncture, diameter (inches) Rupture: Circumferential – Separation Longitudinal – Tear/Crack, length (inches) Propagation Length, total, both sides (feet) N/A Other: Operator Name and Address Original Report Supplemental Report Final Report a. Operator's 5-digit Identification Number (when known) / / b. If Operator does not own the pipeline, enter Owner’s 5-digit Identification Number (when known) / / c. Name of Operator ______________________________ _______________________________________________________ d. Operator street address ________________________________________________________________________________________ e. Operator address _______________________ City, County or Parrish, State and Zip Code 2. Time and date of the incident / / / / / / / / hr. month day year 3. Location of incident 5. Consequences (check and complete all that apply) a. Fatality Total number of people: / / Employees: / / General Public: / / Non-employee Contractors: / / b. Injury requiring inpatient hospitalization Total number of people: / / Employees: / / General Public: / / Non-employee Contractors: / / c. Property damage/loss (estimated) Total $ Gas loss $ Operator damage $ Public/private property damage $ d. Release Occurred in a ‘High Consequence Area’ e. Gas ignited – No explosion f. Explosion g. Evacuation (general public only) / / people Reason for Evacuation: Emergency worker or public official ordered, precautionary Threat to the public Company policy 6. Elapsed time until area was made safe: / / hr. / / min. 7. Telephone Report / / / / / / / / NRC Report Number month day year 8. a. Estimated pressure at point and time of incident: PSIG b. Max. allowable operating pressure (MAOP): PSIG c. MAOP established by 49 CFR section: 192.619 (a)(1) 192. 619 (a)(2) 192. 619 (a)(3) 192.619 (a)(4) 192. 619 (c) d. Did an overpressurization occur relating to the incident? Yes No PART B – PREPARER AND AUTHORIZED SIGNATURE Area Code and Telephone Number (type or print) Preparer's Name and Title Preparer's E-mail Address Area Code and Facsimile Number Date Area Code and Telephone Number Authorized Signature (type or print) Name and Title Form RSPA F 7100.2 ( 01-2002 ) OPS Data Facsimile Page 1 of 3 1 of 3#

Page 13130195 Appendix 6 - Incident report 20090055-6145 PART C - ORIGIN OF THE INCIDENT 1. Incident occurred on Transmission System Gathering System Transmission Line of Distribution System 2. Failure occurred on Body of pipe Pipe Seam Joint Component Other: 3. Material involved (pipe, fitting, or other component) Steel Plastic (If plastic, complete all items that apply in a-c) Plastic failure was: a.ductile b.brittle c.joint failure Material other than plastic or steel: _________ 4. Part of system involved in incident Pipeline Regulator/Metering System Compressor Station Other: 5. Year the pipe or component which failed was installed: / / PART D – MATERIAL SPECIFICATION (if applicable) PART E – ENVIRONMENT 1. Nominal pipe size (NPS) / / in. 2. Wall thickness / / in. 3. Specification SMYS / / 4. Seam type 5. Valve type 6. Pipe or valve manufactured by in year / / 1. Area of incident In open ditch Under pavement Above ground Under ground Under water Inside/under building Other: 2. Depth of cover: inches PART F – APPARENT CAUSE Important: There are 25 numbered causes in this section. Check the box to the left of the primary cause of the incident. Check one circle in each of the supplemental items to the right of or below the cause you indicate. See the instructions for this form for guidance. F1 – CORROSION If either F1 (1) External Corrosion, or F1 (2) Internal Corrosion is checked, complete all subparts a – e. a. Pipe Coating b. Visual Examination c. Cause of Corrosion Bare Galvanic Stray Current 1. External Corrosion Localized Pitting Coated General Corrosion Improper Cathodic Protection Other: ____________________ Microbiological Stress Corrosion Cracking Other: ____________________ 2. Internal Corrosion d. Was corroded part of pipeline considered to be under cathodic protection prior to discovering incident? No Yes, Year Protection Started: / / e. Was pipe previously damaged in the area of corrosion? No Yes, How long prior to incident: / / years / / months F2 – 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 F3 - EXCAVATION 8. Operator Excavation Damage (including their contractors) / Not Third Party 9. Third Party Excavation Damage (complete a-d) a. Excavator group General Public Government Excavator other than Operator/subcontractor b. Type: Road Work Pipeline Water Electric Sewer Phone/Cable Landowner Railroad Other: c. Did operator get prior notification of excavation activity? No Yes: Date received: / / mo. / / day / / yr. Notification received from: One Call System Excavator Contractor Landowner d. Was pipeline marked? No Yes (If Yes, check applicable items i – iv) i. Temporary markings: Flags Stakes Paint ii. Permanent markings: Yes No iii. Marks were (check one) Accurate Not Accurate iv. Were marks made within required time? Yes No F4 – 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 2 of 3 Form RSPA F 7100.2 ( 01-2002 ) Page 2 of 3#

Page 14130195 Appendix 6 - Incident report 20090055-6145 F5 – MATERIAL AND WELDS Material 14. Body of Pipe => Dent Gouge Wrinkle 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 F5. 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 incident occurred? Yes, complete d-g No d. Date of test: / / mo. / / day / / yr. e. Test medium: Water Natural Gas Inert Gas Other: f. Time held at test pressure: / / hr. g. Estimated test pressure at point of incident: PSIG F6 – EQUIPMENT AND OPERATIONS 20. Malfunction of Control/Relief Equipment => Valve Instrumentation Pressure Regulator Other: 21. Threads Stripped, Broken Pipe Coupling => Nipples Valve Threads Mechanical Couplings Other: 22. Ruptured or Leaking Seal/Pump Packing 23. Incorrect Operation a. Type: Inadequate Procedures Inadequate Safety Practices Failure to Follow Procedures Other: b. Number of employees involved who failed post-incident drug test: / / Alcohol test: / / c. Were most senior employee(s) involved qualified? Yes No d. Hours on duty: / / F7 – OTHER 24. Miscellaneous, describe: 25. Unknown Investigation Complete Still Under Investigation (submit a supplemental report when investigation is complete) PART G – NARRATIVE DESCRIPTION OF FACTORS CONTRIBUTING TO THE EVENT (Attach additional sheets as necessary) Form RSPA F 7100.2 ( 01-2002 ) OPS Data Facsimile Page 3 of 3 3 of 3#

Page 15130195 Appendix 7 - Maps Route 13/20 Broad Run Rd: Elk River RaN Columbia Gas Clendenin Compressor Station 4 Latitude: 38°29'43"N Longitude: 81°18'44"W 200 m 1000# 11 DigitalGlobe. USDA FS4 e Agency, GeoEye, U.S. Geological Survey, Map data ©2011 Google - Terms of Use 3 West Union Road Clendenin WV 25045 Clendenin Compressor Station Columbia Gas 02011 Gabgle - Imagery ©2011 DigitalGlobe Agency, GeoEye, U.S. Geological Survey, Map data ©2011 Google - Terms of Use 1 of 1#