Railroad Commission of Texas Pipeline Evaluation System Investigation Report Inspection Package ID = 116917 6/7/18 3:21 PM Incident ID: Page 1 of 5 1693 Contacts Company ID: 6776 Company Name: ATMOS ENERGY CORP., MID-TEX DIVISION Alternate Company Name: Contact Type Name Pipeline Operator Marlo Sutton Onsite Contact Ken Parks Company / Affiliation ATMOS ENERGY CORP., MID-TEX DIVISION ATMOS ENERGY CORP., MID-TEX DIVISION Incident Detail Investigation Status: Original Approved - Waiting for Supplemental/Final Date of Incident: 1/1/18 4:57 AM Drill? No Date Reported: 1/1/18 7:20 AM Inspector Notified Date: 1/1/18 2:26 PM Assigned Inspector: San Sein Incident Location Nearest City: Irving Location/Street Address: 3567 Colgate Ln Region: Fort Worth County: DALLAS Phone Number 214-957-3295 214-316-4911 Railroad Commission of Texas Pipeline Evaluation System Investigation Report Inspection Package ID = 116917 6/7/18 3:21 PM Incident ID: Page 2 of 5 1693 Notes Synopsis On Monday, January 1, 2018 at 4:57 am, a natural gas ignition and an explosion occurred at 3567 Colgate Ln. There were no injuries as a result of the incident. Subsequent investigation revealed that there was a natural gas leak at a 6 inch polyethylene natural gas main mechanically jointed connection. Further investigation revealed that there was a separation between a 6 inch polyethylene gas main and a 6 inch bolted mechanical coupling in which it was connected. The natural gas distribution system is owned and operated by Atmos Energy. Sketches of all surveys, historical records, leak diagrams, etc., were retained by Atmos Energy. Investigation (Include a probable cause statement for incident/accident investigation) Operator's Operations and Maintenance Manual of Gas Leak Surveys-Classification of Leaks (9.4) was reviewed. Operator considers Grade-1 Leak as follow: "A leak that represents an existing or probable hazard to persons or property that requires immediate repair or continuous action until the conditions are no longer hazardous." Operator's gas migration survey records confirmed that a sewer leak check to 3567 Colgate Ln was last performed on 9:21 pm, December 31, 2017 with no recorded natural gas reading. Since then, no additional sewer checks were performed. The below ground gas migration surveys were last performed on 2:30 am of January 1, 2018. There were no continuous actions taken during and leading up to the gas ignition and explosion at 4:57 am of January 1, 2018 while attempting to eliminate a natural gas leak. At 4:57 am January 1, 2018, the structure of 3567 Colgate Ln was ignited then followed by explosion. The post incident sewer check was then performed again on 9:00 am January 1, 2018 with no recorded natural gas reading. Atmos gas migration survey indicated that the air inside the structure of 3567 Colgate Ln was not tested for the presence of a natural gas while attempting to eliminate a natural gas leak outside the structure. Operator's personnel qualification records were reviewed on individuals involved in responding to the leak prior to the incident. Emergency Response (Complete for incident/accident investigations) 7:55pm / 12/31/17Atmos received call from IFD report of gas odor in the air. 8:23pm / 12/31/17Atmos Technician dispatched to location of O'Connor Rd and Colgate Ln. for odor complaint. 9:00pm / 12/31/17Atmos Technician arrived at location. 9:00pm / 12/31/17Atmos Technician conducted bar hole tests at Colgate Ln. and O'Connor Rd, with Sensit S/N 26403. 9:20pm / 12/31/17Atmos Technician pinpointed area at O'Connor Rd. and Colgate Ln., Created Leak No. 576035, Grade 1. 9:21pm / 12/31/17Atmos Technician requested crew for digging out leak. Locate Ticket No. 1786563792. 10:00pm / 12/31/17Atmos 3-man crew arrived at location, unloaded and began digging at O'Connor Rd. and Colgate Ln. 12:06am / 12/31/17Atmos Technician bar hole tested in alley between Colgate Ln. and Princeton Dr. Railroad Commission of Texas Pipeline Evaluation System Investigation Report Inspection Package ID = 116917 6/7/18 3:21 PM Incident ID: Page 3 of 5 1693 2:30am/ 1/1/18Atmos Technician bar hole tested gas main on O'Connor Rd, street corner, yard and at corner of house at 3567 Colgate Ln. w/ Trak-It S/N 5347. 2:53am / 1/1/18Atmos crew contacted 911 for additional assistance on traffic control. 3:15am / 1/1/18Irving Fire Department arrived on location. Atmos crew began digging two additional squeeze locations. 4:57am / 1/1/18House at 3567 Colgate Ln ignited. Irving F.D. evacuated 4 residents from house. No injuries reported. 6:30am / 1/1/18Atmos crew was given return to work. Leak squeezed and eliminated. 7:25am / 1/1/18Atmos notified PHMSA No. 1200886 7:35am / 1/1/18Atmos notified RRC No. 1693 8:30am / 1/1/18Atmos Technicians bar tested service risers in alley North of Colgate Ln. (Six houses, 9-holes on N. side of Colgate Ln.) and in alley South of Colgate Ln. (Six houses, 11-holes on S. side of alley.) w/ Trak-It S/N 6119. 9:00am / 1/1/18Atmos Technicians bar tested sewer vents on Six houses on North side of Colgate, and Six houses on South side of Colgate. Used Sensit Gold CG-1, S/N 18061 and Extender pole. 9:30am / 1/1/18Atmos Technicians bar tested at alleys and intersection of O'Connor Rd and Bellah Dr, w/ Sensit Gold CGI S/N 18061. 11:20am / 1/1/18Second crew arrived to relieve first crew. First crew left for drug and alcohol testing. 11:21am / 1/1/18Atmos Technicians bar tested around perimeter of house, w/ Trak-It3 S/N 6119. 11:25am / 1/1/18Second crew fully exposed leaking 6-inch mechanical coupling. 1:10pm / 1/1/18Additional mobile leak survey identified two additional leaks #576047 and #576048. Both repaired. 1:25 pm/ 1/1/18Atmos crew removed 4-foot section of the 6-Inch line and coupling. Butt fusions new section. 3:00pm / 1/1/18Atmos crews bar tested additional areas from house to streets: both O'Connor Rd. and Colgate Ln., w/ Trak-It3 S/N 6119. 7:02pm / 1/1/18Atmos Technicians performed Odorant Tests at service riser at 3567 Colgate and removed meter and regulator. Railroad Commission of Texas Pipeline Evaluation System Investigation Report Inspection Package ID = 116917 6/7/18 3:21 PM Incident ID: Page 4 of 5 1693 Operator - 30 Day Report Part A-Key Report Information by operator Report is final? No OPS Operator Identification Number: 31348 NRC Number (from Incident Detail): 1200886 Volume of commodity released unintentionally: Volume of commodity released intentionally: Volume of commodity recovered: 465 0 0 Fatalities? No Operator employees: 0 MCF Injuries requiring inpatient hospitalization? No Operator employees: 0 Contractor employees working for the Operator: 0 Non-Operator emergency responders: 0 Workers working on the right-of-way, but NOT associated with this Operator: 0 General Public: 0 Total Fatalities: 0 Contractor employees working for the Operator: 0 Non-Operator emergency responders: 0 Workers working on the right-of-way, but NOT associated with this Operator: 0 General Public: 0 Total Injuries: 0 Part C-Additional Facility Information by operator Incident Occured On: Main Failure Occured On: Joint Connection Failure Material Involved: Polyethelene Plastic-Failure was: Polyethylene (PE) Install Year: 1972 Part D-Additional Consequence Information by operator HCA or USA? No Public and non-operator costs: Cost of commodity unintentionally released: Cost of commodity intentionally released: Cost of property damage and repair: Cost of emergency response: Cost of environmental remediation: $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 $ 0.00 Other costs: $ 0.00 Total costs: $ 0.00 Part G-Apparent Cause from operator Incident Cause (Confirmed): Still under investigation Sub-cause: Unknown Part H-Operator Incident Summary Additional NRC Report No. 1200977 An Atmos Energy construction crew was making repairs on a 6" poly main near the intersection of Colgate Lane and O'Connor Road. At the request of Atmos Energy to provide assistance, the Irving Fire Department arrived on site at approximately 3:00 - 3:15 a.m. At approximately 5:00 a.m. there was a structure fire at 3567 Colgate Lane. At 7:06 Railroad Commission of Texas Pipeline Evaluation System Investigation Report Inspection Package ID = 116917 6/7/18 3:21 PM Incident ID: Page 5 of 5 1693 a.m., an Atmos Energy representative was allowed on site and confirmed the discovery of a potential natural gas reportable incident. A telephonic report was made to PHMSA (NRC 1200886) at 7:25am and the Texas Railroad Commission (TRRC1693) at approximately 7:35 a.m. As of the filing of this report the cause of the structure fire at 3567 Colgate is still under investigation.