Michael L. Williams, Chairman Victor G. Carillo, Commissioner Elizabeth A. Jones, Commissioner INTERNAL Mary L. McDaniel, P.E., Director Pipeline Safety Section TO: FROM: DATE: SUBJECT: Attachment Mary L. McDaniel, P.E. J. M. Ker], P.E. April 9, 2008 Accident Investigation No. 07-0673 Atmos Energy Inc., Mid-Tex Division 632 E. Woodard Ave, Cleburne, Texas May 29, 2007 The attached accident investigation has been regional level. reviewed and approved 'at the - J.M. I Re onal Supervisor A I A I I A Michael L. Williams, Chairman Victor G. Carillo, Commissioner Elizabeth A. Jones, Commissioner INTERNAL SAFETY DIVISION Mary L. McDaniel, P.E., Director Pipeline Safety Section TO: THRU: FROM: DATE: SUBJECT: II. IV. VI. VII. Mary L. McDaniel, P.E. J. M. Kcrl, P.E. S. S. Sein April 9, 2008 Accident Investigation No. 07-0673 Operator: Investigation Location: Date of Accident: Date of Investigation: Applicable Rules and Regulations: Possible Violations: Recommendations: Atmos Energy Corp. 632 Woodard Ave Cleburne, Texas Tuesday, May 29, 2007 May 29, 2007 to April 9, 2008 49CF Part 192 and 16TAC 192-617-002 l6C-205-004 None San Sein Engineering Specialist RAILROAD COMMISSION OF TEXAS SAFETY DIVISION PIPELINE SAFETY ACCIDENT INVESTIGATION REPORT Operator: Location: Date of Accident: Investigated By: Reviewed and Approved By: Date: Issued on 07-0673 Atmos Energv Com, Mid-Tex Division 632 Woodard Ave Cleburne Texas Tuesday, May 29, 2007 S. Scin J. M. Kerl mitt-(? Mary i cDaniel, P.E. Director, Safety Division LHui/Lav! RAILROAD COMMISSION OF TEXAS SAFETY DIVISION PIPELINE SAFETY FINAL REPORT ACCIDENT INVESTIGATION REPORT 07-0673 Operator: Atmos Energy Corp., Mid-Tex Division Location: 632 Woodard Ave Cleburne, Texas Date of Accident: Tuesday, May 29, 2007 Prepared By: g: San Sein Engineering Specialist Investigation Time: Hours Travel Time: 16 Hours Report Preparation Time: 23 Hours TABLE OF CONTENTS Report No. 07-0673 1 I. INVESTIGATION A. The Accident 2 B. The Accident Site 2 C. The Pipeline System 2 D. Post?Accident Activities 2-6 II. INJURIES AND DAMAGES A. Injuries to Persons 7 B. Damages 7 METEOROLOGICAL INFORMATION 7 IV. EVALUATION OF RESPONSE AND PROGRAM EFFECTIVENESS 8 V. FINDINGS A. Findings of Fact 9-10 APPENDIX Appendix A: - RRC Odor Test Form 11 Appendix B: Photographs 12 - 14 Synopsis On Tuesday, May 29, 2007, at approximately 5:04 pm, a structure ?re and explosion occurred at 632 Woodard Ave in Clebume, Texas. There were three injuries and two fatalities as a result of the incident. Natural gas concentrations were found along the street in front of the residence and gas migration was detected along the driveway and towards the house. Subsequent investigation revealed natural gas leaks were found on a vacant service stub compression coupling and two vacant service taps. The natural gas distribution system is owned and operated by Atmos Energy Corp. INVESTIGATION A. The Accident On Tuesday, May 29,? 2007, at approximately 5:04 pm, a structure ?re and explosion occurred at 632 Woodard Ave in Cleburne, Texas. Natural gas concentrations were found along the main in front of the residence and along Woodard Ave. Subsequent investigation revealed natural gas leaks on a inch vacant service stub compression coupling and two vacant service taps along the Atmos Energy natural gas main. Gas migrations were detected along the driveway and towards the house. The sewer vent and sewer clean out for 632 Woodard showed 21 percent and 50 percent natural gas concentrations, respectively. B. The Accident Site The structure fire and explosion occurred at 632 Woodard Ave in Cleburne, Texas. The residence was one-story brick exterior with a concrete slab foundation. There was no natural gas service to the residence. The house is located in a residential neighborhood. This is a class three location. C. The Pipeline System The four-inch natural gas main supplying the 600 block of Woodard Ave is coated steel pipe. It was installed in 1963 (ER The operating pressure at the time of the incident was approximately 20 psig. The maximum allowable operating pressure is 55 psig. The inch coated steel vacant service stub at 632 Woodard Ave was installed in 1963 (BR no. 3-63). It was approximately 20 feet extended towards the south side of the four?inch natural gas main. D. Post Accident Activities 1. Sequence of Events The following activities occurred on May 29 to June 1, 2007. The times listed below are approximate. May 29: 2007 4:00 pm. City of Cleburne Fire Inspector, Mr. Scott Oesch received a call from Mr. David Pollock stated that blue ?ame shoots up to the ceiling when lighting a cigarette. 5:04 pm. 5:12 pm. 6:00 pm. 6:15 pm. 6:20 pm. 6:30 pm. 6:40 pm. 7:15 pm. 8:40 pm. 9:20 pm. 9:25 pm. Ma 30 2007 12:00 am. 12:50 am. Cleburne Fire Department called Atmos Energy?s Dispatch to report a possible explosion/?re at 632 Woodard Ave. Leak Investigation Order was dispatched to Service Technician, J. Kemp with Atmos Energy. Atmos Energy?s Dispatch noti?ed manager on call. Mr. Kemp reported the natural gas readings he found to the Clebume Fire Department and expanded the investigation. Atmos Dispatch noti?ed the Pipeline and Hazardous Materials Safety Administration (DOT). Cleburne Fire Department initiated evacuation. Atmos Dispatch noti?ed the Railroad Commission of Texas, Pipeline Safety Division of the accident. Atmos Energy?s supervisor Pete Peterson arrived onsite. RRC personnel S.Sein and J. Kerl arrived onsite to conduct an investigation. An odor test was taken by Atmos Energy and RRC personnel at 634 Woodard Ave. The malodorant was rated as strong at 0.17 gas-in-air. Atmos Energy and RC personnel began bar testing the natural gas main and services in the 600 block of Woodard Ave. Atmos Energy continued to bar test. Atmos Energy found a leak at 632 Woodard Ave. and the leak is rated as grade I leak with a 94 percent gas concentration. 1:00 am. 1:10 am. 3:30 am. 5:45 am. 7:30 am. 8:30 am. 9:15 am. 9:30 am. 3:30 pm. Ma 31 2007 12:00 am. 12:40 am. Atmos Energy found a leak at 700 Woodard Ave. and classi?ed the leak as a grade 3 leak with a 53 percent gas concentration. Atmos Energy found a leak at 634 Woodard Ave. and classi?ed the leak as a grade 3 leak with a 82 percent gas concentration. Atmos Energy continued to leak survey the 600 block of Woodard Ave. and gas concentrations were found along the main. Atmos Energy excavated the leak at 632 Woodard Ave. A inch vacant service stub compression coupling was found to be leaking. The vacant service stub did not appear to be separated or pulled out from the compression coupling. Atmos Energy personnel applied liquid soap to the compression coupling wing nut, and a natural gas leak at the compression coupling was observed. The vacant service stub at 632 Woodard was retired. Cleburne Fire Department began to lift the evacuation. The ?ttings at the two vacant service taps were replaced and this repaired the natural gas leaks found at 634 and 700 Woodard. Atmos Energy continued to aerate and monitor the natural gas migration toward 632 and 634 Woodard Ave. and in the area. RRC personnel departed the scene. Atmos Energy continued to aerate and monitor the natural gas migration. Cleburne Fire Department released evacuation to 634 Woodard Ave. May 31-June 1: 2007 RC investigator S. Sein met with Atmos Energy representatives Messrs. J. Martinez, P. Peterson, K. Slaughter, and R. Oliver at 100 W. Morningside, Ft. Worth, TX. Selected procedures, maps and records were reviewed. . Odor Test Data On Tuesday, May 29, 2007, a malodorant test was taken and the malodorant was found to be strong at a concentration of 0.17% by volume gas in air. . Bar Test Data On Tuesday, May 29, 2007, Atmos Energy personnel bar tested the natural gas main and services along the 600 block of Woodard Ave. Natural gas readings were detected along the street and towards the 632 and 634 Woodard Ave. . Records Reviewed A. Leakage Survey Records The natural gas main and services along the 600 block of Woodard Ave are located on Atmos Energy map sheet: AG027248. Records show that the natural gas main and services on this map sheet were last leak surveyed on August 3, 2006. B. Leak Complaint History Atmos Energy leak investigation orders (LIOs) were reviewed for the period between May 2002 and the date of the accident. This included the area surrounding the 600 block of Woodard Ave. Leak complaints at 626 Woodard Ave and 618 Woodard Ave were reported to Atmos Energy on December 8, 2003 and December 5, 2002, respectively. The leaks were found on customer owned service lines. The numbers were 489127 and 401385. C. Cathodic Protection Records The natural gas main and services along the 600 block of Woodard Ave have been cathodically protected since 10/9/89 and are designated as Zone 16M. The last pipe to soil survey on Zone 16-M was last conducted on July 7, 2006 with readings above the required -.85 volt criteria. I D. Leak History Records Atmos Energy repaired leak records prior to the date of the accident were reviewed. This included the area surrounding the 600 block of Woodard Ave. The leaks were repaired at 634 Woodard Ave and 606 Woodard Ave. They were repaired on May 2, 2004 and April 21, 2004, respectively. The leaks were found on service lines. The leak numbers were 336193 and 336192. E. Line Location Records Line locate records showed utility line Locate ticket No. 063451960 for intersection of 632 Woodard Ave and Gatrix Ave that was requested for the City of Cleburne on December 11, 2006. The ticket noted that ?Locate PROP Line to PROP Line Both sides of STREET AND The nature of work was trenching. There appeared to be no evidence of excavation activity near or at the vacant service stub at 632 Woodard Ave. F. Procedure Review The Atmos Energy Operation and Maintenance Plan was reviewed. Procedure 3-5 addresses leakage surveys. The natural gas leak survey for effectively coated steel pipes are to be conducted at intervals not exceeding 60 months. G. Other pertinent information 1. Cleburne Fire Department Report According to the Cleburne Fire Department report reviewed, the source of the ignition was listed as a cigarette. 2. Metallurgical Report On January 25, 2008, S. Sein met with Mr. Jeff Martinez from Atmos Energy regarding the metallurgical analysis conducted on the compression coupling at 632 Woodard Ave, Cleburne, Texas. According to Mr. Martinez, the analysis results were forwarded to Austin HQ for further review. The metallurgical report conducted by Anderson Associates (AA Job No:070974) was reviewed at Austin II. HQ on February 5, 2008. The report showed damage of the vacant stub compression coupling retaining ring and seal gasket at the 12 O?Clock position. Mr. Martinez con?rmed that the damage had been caused during the removal of the compression coupling. Additional leakage history record search was conducted on compression coupling at 632 Woodard Ave, Cleburne, Texas. On March 7, 2008, Mr. Martinez con?rmed that no repair record prior to the date of the accident was found. INJURIES AND DAMAGES A. Injuries to Persons Injuries Companv Personnel Others Iota] Fatal -0- -2- Nonfatal i Total -5- -5- There were six people at home at the time of the accident. Three were reported injured and hospitalized. There were two fatalities, Mrs. Hazel Pawlik, a 64-year old female and Mrs. Hazel Sanderson, a 44-year old female. B. Damage 1. Damage to Pipeline Facilities There was no damage to the pipeline facilities as a result of the structure ?re and explosion. 2. Damage to Structure As a result of the structure ?re, most of the house was destroyed. According to Atmos EnergY, the damaged was estimated to be $250,000.00. METOROLOGICAL INFORMATION The Local Climatological Data for Dallas/Fort Worth on 5/29/2007 is listed below. High (Fahrenheit) - 88 degrees Low (Fahrenheit) - 66 degrees Precip (Inches) 2.39 Weather did not appear to be a factor in the accident. IV. EVALUATION OF RESPONSE AND PROGRAM EFFECTIVENESS The incident occurred on Tuesday, May 29, 2007, at approximately 5:04 pm. Atmos Energy Dispatch was noti?ed. Mr. J. Kemp, service representative, arrived onsite at 6:15 pm. At that time, Mr. Kemp implemented emergency investigation procedures. Mr. Kemp noti?ed appropriate supervisory personnel. Atmos Energy noti?ed the Pipeline and Hazardous Material Administration at 6:20pm. and the Railroad Commission Emergency number at 6:40pm. After this occurred, a plan of action was discussed and implemented. It appears that Atmos Energy followed their procedures during all activities after the accident occurred. V. FINDINGS Findings of Fact 1. On Tuesday, May 29, 2007 at approximately 5:04 pm, a structure ?re and explosion occurred at 632 Woodard Ave. in Cleburne, Texas. There were three injuries and two fatalities as a result of the accident. Natural gas concentrations were found along the main in front of the residence and along the 600 block of Woodard Ave. Subsequent investigation revealed that leaks were found on a inch vacant service stub compression coupling and two vacant service taps. The vacant service stub was located at 632 Woodard Ave and vacant service taps were located at 634 and 700 Woodard Ave. It did not appear that the vacant service stub was separated or pulled out from the compression coupling. Atmos Energy personnel applied liquid soap to the compression coupling wing nut, and a natural gas leak at the compression coupling was noted. The metallurgical report conducted by Anderson Associates (AA Job No:070974) was reviewed at Austin HQ on February 5, 2008. The report showed damage of the vacant stub compression coupling retaining ring and seal gasket at the 12 O?Clock position. Mr. Martinez con?rmed that the damage had been caused during the removal of the compression couphng. An odor test was conducted and the malodorant was rated as strong at 0.17 percent gas-in?air. The main and services for the 600 block of Woodard Ave are located on Atmos Energy map sheet: AGOZ7248. Records document the main and services on this map sheet were last leak surveyed on August 8, 2006. According to the Cleburne Fire Department report, the source of ignition appears to be a cigarette. The natural gas distribution system is owned and operated by Atmos Energy, Corp. The probable cause of the incident was natural gas leaks along the Atmos Energy natural gas main that had migrated natural gas to the residence at 632 Woodard Ave, Cleburne, Texas. 10 APPENDIX A Railroad Commission of Texas Supplemental Odorization Evaluation Form Company Name; 6.5 19th 3 Evaluation Number: 7" 0675 Ci@ cliiamne Date: 57/35! System Type: Distribution Transmission Master Meter Odorized By: Supplier Natural None Odorization Tests: Meter Sniff None No. of Odorizers: . Odorizer Code: Odorant Code: Odorizer Location: GPS Coordinate: Date: Odorant Beginning lbs. Gal. MMCF Inject Rt. Odorant Added lbs. I Gal. Farm Taps Adequate Yes No l. Odorant End Ga Odor Test Adequate 2 Yezgzg?egtipnr Yes No Instrument Used: .J.W. Odorometer eathte Other Serial# 8 *3 DUC 522 Location of Test: ?34 771 . Test Date: 9 07' I . Odorizer Distance: 94] mes/ ards/Feet TestTime: 2: 91,0 TEST 1 Percent gas in Odorometer ef?uent (from meter chart)when ?rst detected 0 ?2 2 TEST 2 Odorant Concentration at 1% Gas in Air Odor Intensity Rating: Absent Barely Readily Strong xtreme Evaluatorz%$\ Witness: 1/ 3, '27 A a] Odorizer HOok- -up or Comments: FL Wig/? r5 ar liequL PS-28 rn~oel5 ng to M7 Ix . 3?33? 27w awvaooM if? 94m if; EAV ?mix 9.x 539% 937.31%: ?96 Ck 2m ?76?39 zby?zs?aa) as am? $19,293 25/29 7?1?13940 9,;0 ?20 go . I Dri?wvmg 3 039 a! w: and?) APPENDIX Distribution Evaluation Data (enter new evaluation data in boxes with dotted borders) company?id: 6776 company: ATMOS ENERGY CORP., MID-TEX unit_id: 3305 unit: ATMOS system__id: 610103 system: CLEBURNE *system_code: DID systemmiles: 713950 endusers?i??uwl; install_yrr'1929 t4no: 99999 previous evaluation_no: :9 enter new_evaluation_no 5.70; 06 75 begin_date: 312942051] end_date: L?229?2_00?j evalrs: 5/47/07 ?flaps $25 *activity: 73' *classification: region: 630000007? Q, 7 miles_ evaltd: #00? num__of__endusers: 07:0 7 integrity_code: 0 number_violations_cited 2 7 7 from: to: Iost_unacctforgas_iune ending from: 0000 to: 0000 mcf_purchased: 77777777777777777777777777 1 mcf_purchased: mew?: _jj_j j; museum WW6 Lu 649959?. 32:: mcf_lost: 7 mcf_lost: QT *accident_cause: .23? 6 3 number_fatalities: 2 number_injuries: if 3 propenLdamage: 3 W9 2 57; age} canin-no: 9'7?56925789, person 1 contacted: person 2 contacted: Title 1: Title 2: personnel contacted at: county locations JOHNSON violations cited new_code old_code est_completion conf_completion repeat For use of codes, procedural guidance, and blank forms, go to the "Forms and Procedures" button on the "package_builder" form. 4/9/2008 Page 1 of 1 :ull Number: 403E375 LEAK ("lulu-raw 03d Wumhml Ave .- me FoundGrade: 3 urvoy .lull t" Smut-ll: T: erlml" .. . I I .us Ilulrulml: Hull mu. ?luau" 3 Li . 82 Autumn": mt. ., llm- 'lml l?llt'll lnll'f- Mumllull Am? 724" .. 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