{"operation":"document","citation":"DCA00MP009","title":"Natural Gas Pipeline Rupture and Fire","source_type":"incident","agency":"National Transportation Safety Board","status":"current","official":true,"published_on":"2026-01-30","effective_on":"2000-08-19","summary":"Accident. in Pecos, NM, USA. on 2000-08-19. El Paso Natural Gas Company. Rupture/fire","machine_formats":{"json":"https://regulus.evalyn.ai/document/ntsb-case-dca00mp009.json","markdown":"https://regulus.evalyn.ai/document/ntsb-case-dca00mp009.md"},"app_url":"https://regulus.evalyn.ai/document/ntsb-case-dca00mp009","source_url":"https://www.ntsb.gov/investigations/Pages/DCA00MP009.aspx","body":"NTSB investigation DCA00MP009.\n\nEvent Type: Accident\n\nEvent Date: 2000-08-19\n\nEvent City: Pecos\n\nEvent State Or Region: NM\n\nEvent Country: USA\n\nPipeline Operator: El Paso Natural Gas Company\n\nPipeline Type: Gas Transmission - Regulated\n\nAccident Type: Rupture/fire\n\nCompletion Status: Completed\n\nReport Number: PAR-03-01\n\nProbable cause: The National Transportation Safety Board determines that the probable cause of the August 19, 2000, natural gas pipeline rupture and subsequent fire near Carlsbad, New Mexico, was a significant reduction in pipe wall thickness due to severe internal corrosion. The severe corrosion had occurred because El Paso Natural Gas Company’s corrosion control program failed to prevent, detect, or control internal corrosion within the company’s pipeline. Contributing to the accident were ineffective Federal preaccident inspections of El Paso Natural Gas Company that did not identify deficiencies in the company’s internal corrosion control program.\n\nTier1Name: System operating\n\nTier2Name: Fire/explosion (post-release)\n\nTier1Name: System operating\n\nTier2Name: Pipe structural malfunction/failure\n\nFinding Tier1Name: Organizational\n\nFinding Tier2Name: Support/oversight/monitoring\n\nFinding Tier3Name: Oversight\n\nFinding Modifier Name: Federal agency\n\nFinding Report Text: Organizational - Support/oversight/monitoring - Oversight - Federal agency\n\nFinding Tier1Name: Organizational\n\nFinding Tier2Name: Support/oversight/monitoring\n\nFinding Tier3Name: Oversight\n\nFinding Modifier Name: Other institution/organization\n\nFinding Report Text: Organizational - Support/oversight/monitoring - Oversight - Other institution/organization\n\nFinding Tier1Name: Pipeline\n\nFinding Tier2Name: Pipeline structure\n\nFinding Tier3Name: Pipe\n\nFinding Modifier Name: Fatigue/wear/corrosion\n\nFinding Report Text: Pipeline - Pipeline structure - Pipe - Fatigue/wear/corrosion\n\nOfficial NTSB investigation data. NTSB findings determine probable cause and make safety recommendations; they do not adjudicate civil liability or regulatory violations.\n\nWhat Happened\nAt 5:26 a.m., mountain daylight time, on Saturday, August 19, 2000, a 30-inch diameter natural gas transmission pipeline operated by El Paso Natural Gas Company ruptured adjacent to the Pecos River near Carlsbad, New Mexico. The released gas ignited and burned for 55 minutes. Twelve persons who were camping under a concrete-decked steel bridge that supported the pipeline across the river were killed and their three vehicles destroyed. Two nearby steel suspension bridges for gas pipelines crossing the river were extensively damaged. According to El Paso Natural Gas Company, property and other damages or losses totaled $998,296.\n\nWhat We Found\nWe determined that the probable cause of\nthe August 19, 2000, natural gas pipeline rupture and subsequent fire near Carlsbad, New Mexico, was a significant reduction in pipe wall thickness due to severe internal corrosion. The severe corrosion had occurred because El Paso Natural Gas Company's corrosion control program failed to prevent, detect, or control internal corrosion within the companyís pipeline.\nContributing to the accident were ineffective Federal preaccident inspections of El Paso Natural Gas Company that did not identify deficiencies in the companyís internal corrosion control program.\nThe major safety issues identified in this investigation are as follows:\n\nThe design and construction of the pipeline,\nThe adequacy of El Paso Natural Gas Companyís internal corrosion control program,\nThe adequacy of Federal safety regulations for natural gas pipelines, and\nThe adequacy of Federal oversight of the pipeline operator\n\nWhat We Recommended\nAs a result of this investigation, we made the following new safety recommendations.\nTo the Research and Special Programs Administration:\n\nRevise 49 Code of Federal Regulations Part 192 to require that new or replaced pipelines be designed and constructed with features to mitigate internal corrosion. At a minimum, such pipelines should (1) be configured to reduce the opportunity for liquids to accumulate, (2) be equipped with effective liquid removal features, and (3) be able to accommodate corrosion monitoring devices at locations with the greatest potential for internal corrosion. (P-03-1)\nDevelop the requirements necessary to ensure that pipeline operators' internal corrosion control programs address the role of water and other contaminants in the corrosion process. (P-03-2)\nEvaluate the Office of Pipeline Safetyís pipeline operator inspection program to identify deficiencies that resulted in the failure of inspectors, before the Carlsbad, New Mexico, accident, to identify the inadequacies in El Paso Natural Gas Companyís internal corrosion control program. Implement the changes necessary to ensure adequate assessments of pipeline operator safety programs. (P-03-3)\nTo NACE International: Establish an accelerated schedule for completion of an industry standard for the control of internal corrosion in steel pipelines that will replace or update NACE standard RP0175-75. (P-03-4).\n\nPAR-03-01\n<<<PAGE 1>>>\n\nNTSB/PAR-03/01\nPB2003-916501\nPipeline Accident Report\nNatural Gas Pipeline Rupture and Fire\nNear Carlsbad, New Mexico\nAugust 19, 2000\nT\nR\nA\nN\nF\nA\nS\nE\nN\nA\nT\nI\nO\nN\nA\nL\nP\nL\nU\nR\nI\nB\nU\nS\nU\nN\nU\nM\nE\nT\nY\nB\nO\nR\nT\nA\nT\nI\nO\nN\nD\nP\nR\nS\nA\nO\nNational\nTransportation\nSafety Board\nWashington, D.C.\n\n<<<PAGE 2>>>\n\nthis page intentionally left blank\n\n<<<PAGE 3>>>\n\nPipeline Accident Report\nNatural Gas Pipeline Rupture and Fire\nNear Carlsbad, New Mexico\nAugust 19, 2000\nNTSB/PAR-03/01\nPB2003-916501 National Transportation Safety Board\nNotation 7310B 490 LíEnfant Plaza, S.W.\nAdopted February 11, 2003 Washington, D.C. 20594\n\n<<<PAGE 4>>>\n\nNational Transportation Safety Board. 2003. Natural Gas Pipeline Rupture and Fire Near Carlsbad,\nNew Mexico, August 19, 2000. Pipeline Accident Report NTSB/PAR-03/01. Washington, D.C.\nAbstract: At 5:26 a.m., mountain daylight time, on Saturday, August 19, 2000, a 30-inch-diameter natural\ngas transmission pipeline operated by El Paso Natural Gas Company ruptured adjacent to the Pecos River\nnear Carlsbad, New Mexico. The released gas ignited and burned for 55 minutes. Twelve persons who\nwere camping under a concrete-decked steel bridge that supported the pipeline across the river were killed\nand their three vehicles destroyed. Two nearby steel suspension bridges for gas pipelines crossing the river\nwere extensively damaged. According to El Paso Natural Gas Company, property and other damages or\nlosses totaled $998,296.\nThe major safety issues identified in this investigation are the design and construction of the pipeline, the\nadequacy of El Paso Natural Gas Companyís internal corrosion control program, the adequacy of Federal\nsafety regulations for natural gas pipelines, and the adequacy of Federal oversight of the pipeline operator.\nAs a result of its investigation of this accident, the National Transportation Safety Board makes safety\nrecommendations to the Research and Special Programs Administration and NACE International.\nThe National Transportation Safety Board is an independent Federal agency dedicated to promoting aviation, railroad, highway, marine,\npipeline, and hazardous materials safety. Established in 1967, the agency is mandated by Congress through the Independent Safety Board\nAct of 1974 to investigate transportation accidents, determine the probable causes of the accidents, issue safety recommendations, study\ntransportation safety issues, and evaluate the safety effectiveness of government agencies involved in transportation. The Safety Board\nmakes public its actions and decisions through accident reports, safety studies, special investigation reports, safety recommendations, and\nstatistical reviews.\nRecent publications are available in their entirety on the Web at <http://www.ntsb.gov>. Other information about available publications also\nmay be obtained from the Web site or by contacting:\nNational Transportation Safety Board\nPublic Inquiries Section, RE-51\n490 LíEnfant Plaza, S.W.\nWashington, D.C. 20594\n(800) 877-6799 or (202) 314-6551\nSafety Board publications may be purchased, by individual copy or by subscription, from the National Technical Information Service. To\npurchase this publication, order report number PB2003-916501 from:\nNational Technical Information Service\n5285 Port Royal Road\nSpringfield, Virginia 22161\n(800) 553-6847 or (703) 605-6000\nThe Independent Safety Board Act, as codified at 49 U.S.C. Section 1154(b), precludes the admission into evidence or use of Board reports\nrelated to an incident or accident in a civil action for damages resulting from a matter mentioned in the report.\n\n<<<PAGE 5>>>\n\niii Pipeline Accident Report\nContents\nExecutive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v\nFactual Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1\nAccident Synopsis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1\nAccident Narrative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1\nEmergency Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7\nPipeline Operations After the Rupture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10\nPostaccident On-Site Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10\nInjuries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11\nDamages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12\nToxicological Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12\nTests and Research . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13\nMetallurgical Examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13\nCorrosion Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15\nPipeline 1103 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16\nPipeline Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16\nGas Suppliers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17\nPigging Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18\nTests and Inspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21\nEPNGís Internal Corrosion Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21\nInternal Corrosion Control Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23\nInternal Audit Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25\nRegulatory Oversight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26\nFederal Safety Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26\nPreaccident Federal Inspections of EPNG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28\nFederal Safety Standards and EnforcementÊMaps and Records . . . . . . . . . . . . . . . . . 29\nPostaccident Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30\nPipeline Reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30\nPipeline Integrity Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31\nFederal Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31\nPipeline Integrity ManagementÊFederal Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33\nNACE Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35\nASME Code for Gas Piping (B31.8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35\nGuide for Gas Transmission and Distribution Piping Systems . . . . . . . . . . . . . . . . . . . . . . 36\nOther Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36\nPrevious EPNG Internal Corrosion Accident . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36\nEmergency Training and Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37\nAnalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38\nExclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38\nEmergency Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39\nInternal Corrosion in Steel Gas Pipelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39\nInternal Corrosion in Line 1103 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40\nPhysical Features of Line 1103 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41\nEPNG Internal Corrosion Control Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43\n\n<<<PAGE 6>>>\n\nContents iv Pipeline Accident Report\nFederal Safety Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46\nFederal Oversight of the Pipeline Operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46\nIndustry Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48\nConclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49\nFindings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49\nProbable Cause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50\nRecommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51\nAppendixes\nA: Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53\nB: Summary of Office of Pipeline Safety Corrective Action Order . . . . . . . . . . . . . . . . . . 54\nC: Research and Special Programs Administration Advisory Bulletin . . . . . . . . . . . . . . . . 56\n\n<<<PAGE 7>>>\n\nv Pipeline Accident Report\nExecutive Summary\nAt 5:26 a.m., mountain daylight time, on Saturday, August 19, 2000, a 30-inch-\ndiameter natural gas transmission pipeline operated by El Paso Natural Gas Company\nruptured adjacent to the Pecos River near Carlsbad, New Mexico. The released gas ignited\nand burned for 55 minutes. Twelve persons who were camping under a concrete-decked\nsteel bridge that supported the pipeline across the river were killed and their three vehicles\ndestroyed. Two nearby steel suspension bridges for gas pipelines crossing the river were\nextensively damaged. According to El Paso Natural Gas Company, property and other\ndamages or losses totaled $998,296.\nThe National Transportation Safety Board determines that the probable cause of\nthe August 19, 2000, natural gas pipeline rupture and subsequent fire near Carlsbad, New\nMexico, was a significant reduction in pipe wall thickness due to severe internal\ncorrosion. The severe corrosion had occurred because El Paso Natural Gas Companyís\ncorrosion control program failed to prevent, detect, or control internal corrosion within the\ncompanyís pipeline. Contributing to the accident were ineffective Federal preaccident\ninspections of El Paso Natural Gas Company that did not identify deficiencies in the\ncompanyís internal corrosion control program.\nThe major safety issues identified in this investigation are as follows:\nï The design and construction of the pipeline,\nï The adequacy of El Paso Natural Gas Companyís internal corrosion control\nprogram,\nï The adequacy of Federal safety regulations for natural gas pipelines, and\nï The adequacy of Federal oversight of the pipeline operator.\nAs a result of its investigation of this accident, the National Transportation Safety\nBoard makes safety recommendations to the Research and Special Programs\nAdministration and NACE International.\n\n<<<PAGE 8>>>\n\nthis page intentionally left blank\n\n<<<PAGE 9>>>\n\n1 Pipeline Accident Report\nFactual Information\nAccident Synopsis\nAt 5:26 a.m., mountain daylight time, on Saturday, August 19, 2000, a 30-inch-\ndiameter natural gas transmission pipeline operated by El Paso Natural Gas Company\n(EPNG) ruptured adjacent to the Pecos River near Carlsbad, New Mexico. The released\ngas ignited and burned for 55 minutes. Twelve persons who were camping under a\nconcrete-decked steel bridge that supported the pipeline across the river were killed and\ntheir three vehicles destroyed. Two nearby steel suspension bridges for gas pipelines\ncrossing the river were extensively damaged. According to EPNG, property and other\ndamages or losses totaled $998,296.\nAccident Narrative\nThe EPNG pipeline system (figure 1) transported gas west from Texas and New\nMexico to Arizona and California. A portion of the pipeline system crossed the Pecos\nRiver about 4 1/2 miles north of the Texas-New Mexico State line and 30 miles south of\nCarlsbad, New Mexico. (See figure 2.) About 1 mile west of the river crossing was the\nPecos River compressor station, which received gas from four natural gas transmission\npipelines26-inch-diameter line 1100, 30-inch-diameter line 1103, 30-inch-diameter line\n1110, and 16-inch-diameter line 3191. Three of these lines (1100, 1103, and 1110) ran\nparallel to Whitethorn Road (also known as Pipeline Road) from the Pecos River to the\nPecos River compressor station. Lines 1103 and 1110 were supported at the river crossing\nby a one-lane concrete-decked steel service bridge that was not open to the public. (See\nfigure 3.) (This bridge, which had been built by EPNG in 1950, also supported a water\npipeline and a gas gathering pipeline. EPNG, which was at the time of the accident a\nsubsidiary of El Paso Energy, owned and operated the water pipeline but not the gas\ngathering pipeline.) Line 1100 was supported across the river on a pipeline suspension\nbridge approximately 70 feet northeast of the service bridge. Another EPNG pipeline, 16-\ninch-diameter line 1000, was supported by a separate suspension bridge in this area, but\nthis line had been removed from service and was filled with nitrogen at the time of the\naccident. The fourth pipeline, line 3191, ran from EPNGís South Carlsbad compressor\nstation to the Pecos River compressor station.\n\n<<<PAGE 10>>>\n\nFactual Information 2 Pipeline Accident Report\nFigure 1. El Paso Natural Gas system.\nFigure 2. Accident area.\n\n<<<PAGE 11>>>\n\nFactual Information 3 Pipeline Accident Report\nFigure 3. Accident site.\nAt the time of the accident, 12 members of an extended family were camping on\nthe east bank of the Pecos River near the service bridge.1 (See figure 4.) A locked wire\nrope and a ìPrivate Right of WayNo Trespassingî sign at each entrance to the bridge\nrestricted access to the bridge above the campsite. Two ìCautionHigh Pressure Gas\nLineî signs were posted near the east entrance to the service bridge. Also, a sign reading\nas follows:\nWarning - No Trespassing - This road and right of way is private property and is\nnot for public use. This pipeline carries natural gas under high pressure and is\ndangerous. All persons are warned of the danger to person and property. KEEP\nOFF\nhad been posted alongside the right-of-way road (near the intersection with the county\nroad) leading past the block valves and pig receivers to the service bridge on the east side\nof the river.The pipeline system was operated from EPNGís gas control center in El Paso,\nTexas, as a north system and a south system. The gas control center was equipped with\nthree supervisory control and data acquisition (SCADA)2 system work consoles, each of\nwhich was capable of displaying data for both pipeline systems.\nOn the morning of August 19, 2000, three EPNG employees, a coordinator of\npipeline control (who was in charge of the shift) and two gas controllers, were nearing the\n1 At the time of the accident, a private landowner owned the accident site. After the accident, EPNG\npurchased this property and installed fencing to restrict access to the area.\n2 Pipeline controllers use a computer-based SCADA system to remotely monitor and control\nmovement of gas through pipelines. The system makes it possible to monitor operating parameters critical to\npipeline operations, such as flow rates, pressures, equipment status, control valve positions, and alarms\nindicating abnormal conditions.\n\n<<<PAGE 12>>>\n\nFactual Information 4 Pipeline Accident Report\nFigure 4. Aerial view of accident site looking east.\nend of their 12-hour shifts at the gas control center. One of the controllers was operating\nthe north system and the other the south, while the coordinator assisted the two controllers\nand performed administrative oversight and served as a backup controller when needed.\nThe two controllers were working at separate SCADA terminals to monitor and control\npipeline operations. The employees said they had noted no unusual operating conditions\nduring their shift, and no unusual conditions had been noted during the previous 12-hour\nshift.\nThe south system controller, at 5:26 a.m.,3 received SCADA rate-of-change4\nalarms for the speed of compressor unit No. 3 at the Pecos River compressor station.5 Less\nthan a minute later, compressor unit No. 1 at the station shut down, quickly followed by\nthe automatic closing and opening of station valves, as appropriate, to isolate the\ncompressor station from the pipeline. Emergency lubricating oil pumps were also\nautomatically activated at the station. A few seconds later, additional alarms from the\nstation displayed on the controllerís monitor, including a rate-of-change alarm for falling\n3 Times in this section are based on SCADA event data recorder records, controller logs, and personnel\nstatements and interviews.\n4 Rate-of-change alarms indicate that a measured variable, such as compressor speed or compressor\nsuction pressure, is increasing or decreasing at a rate exceeding what would be expected under normal\noperating conditions.\n5 The unattended Pecos River compressor station had three turbine compressors.\n\n<<<PAGE 13>>>\n\nFactual Information 5 Pipeline Accident Report\nsuction (inlet) pressure at the station. (Unknown to the controller at the time, pressure on\nthe inlet side of the station dropped because pipeline 1103 had ruptured near the river\ncrossing.) Noting the alarms, the south controller began to request SCADA data for the\nPecos River compressor station instead of waiting for the data to appear from the\nautomatic data scans, which occurred at 4-minute intervals.6\nAt about this time, the transmission of SCADA data between the gas control center\nand the Pecos River compressor station was briefly interrupted. According to the south\ncontroller, he was immediately alerted to the data interruption by the display of inverse\nvideo on his SCADA monitor. Inverse video indicated that a proper reply to a request for\ndata from the SCADA system had not been received and that the displayed data were not\nbeing updated. Although not recorded in the SCADA system event log, this interruption\nlasted about 30 seconds.\nAt approximately 5:30 a.m., the controller telephoned the Pecos River district\nstation lead operations specialist7 at home and asked him to send people to the Pecos River\ncompressor station. The south controller later stated:\nI noted that we did have a low suction pressure, and generally when our plants go\ndown, the suction pressure goes up instead of down. I told [the station lead\noperations specialist], ëWe need to get somebody out there right away because I\nthink we have a problem.í\nThe station lead operations specialist called two operations specialists that he\nsupervised and who were on duty and told them to go to the Pecos River compressor\nstation.\nAbout the same time the station lead operations specialist was making this call, an\nEPNG operations specialist from the Carlsbad complex, who was at his home south of the\ncity of Carlsbad, noticed a glow in the sky to the south. (See figure 5.) He said he\nimmediately suspected that an EPNG pipeline may be involved. He called the gas control\ncenter and asked if its personnel had noticed any sudden pressure changes at the Pecos\nRiver compressor station. He told center personnel of the glow in the sky and said that he\nsuspected a rupture. The north controller informed him that EPNG had lost a compressor\nat the Pecos River compressor station.\nThe operations specialist then telephoned his supervisor (the pipeline lead\noperations specialist), and informed him of the glow in the sky and of his call to the gas\ncontrol center. He then told the pipeline lead operations specialist that he was on his way\nto the Pecos River compressor station.\n6 This SCADA system logged operational data and transferred it to the gas control center via modem.\n7 EPNG had two employees in the Pecos River district with the official title ìlead operations\nspecialist.î One lead operations specialist supervised operations specialists responsible for operating and\nmaintaining compressor and meter stations. Another lead operations specialist supervised operations\nspecialists responsible for operating and maintaining pipelines. This report refers to the two employees,\nrespectively, as the station lead operations specialist and the pipeline lead operations specialist.\n\n<<<PAGE 14>>>\n\nFactual Information 6 Pipeline Accident Report\nFigure 5. Post-rupture fire. At lower left of fireball can be seen the 85-foot-tall support\nstructures for the pipeline suspension bridges.\nAt 5:31 a.m., the gas control center in El Paso again experienced an interruption in\nSCADA data transmission from the Pecos River compressor station, which prevented the\ncontrollerís receiving any additional information from the station. The interruption\noccurred when the emergency shutdown system at the Pecos River compressor station\nactivated, which caused a loss of power to the local SCADA computer and modem. The\nstation was equipped with an uninterruptible power supply, but the station SCADA\ncomputer and modem were not connected to it.8 SCADA communications with the Pecos\nRiver compressor station were restored at 9:04 a.m. on August 19.\nAt 5:35 a.m., the south controller again telephoned the station lead operations\nspecialist at home and told him that he suspected a possible line blowout. At this time, the\nsouth controller did not know which pipeline was involved. The station lead operations\nspecialist said that after looking out a window of his home in the direction of the Pecos\nRiver compressor station, he told the south controller that he could see a fire and that he\nwas on his way to the Pecos River compressor station.\n8 The station was equipped with an uninterruptible power supply to maintain AC power to the station\ncomputer and hazardous gas and fire detection equipment. A 24-volt DC backup system maintained power\nto oil pumps, nozzle cooling water equipment, and other emergency equipment in the event of a station\npower failure.\n\n<<<PAGE 15>>>\n\nFactual Information 7 Pipeline Accident Report\nAt 5:44 a.m., the south controller called the Keystone compressor station9 and\nasked the operator to take down three compressor units. About a minute later, he called the\nEunice plant10 and made the same request.\nAt 5:50 a.m., the south controller called El Paso Field Services to make sure that\npersonnel there would shut down all compressor units at the South Carlsbad compressor\nstation.11 The south controllerís shift ended at 6:00 a.m., but he stayed at the gas control\ncenter until 8:00 a.m. to provide assistance as necessary. During this time, he notified the\nEl Paso Energy public relations department in Houston, Texas.12\nEmergency Response\nWithin 5 minutes of the rupture, at 5:31 a.m., the local 911 operator received\nnumerous calls from residents reporting a fire and the sound of an explosion. An off-duty\nEPNG employee who lived near the site also called 911 and reported the fire. The gas\ncontrol center was called by an off-duty operations specialist when he saw light in the sky\nfrom the fire, and he also called the pipeline lead operations specialist for the local section\nof the pipeline.\nThat pipeline lead operations specialist was the first to arrive at the accident site, at\nabout 5:45 a.m. He said that while he was en route, he had spoken with the gas control\ncenter and the EPNG general dispatcher from his truck and had asked the control center to\ncall managers for the Jal and Carlsbad complexes. He recalled that as he neared the Pecos\nRiver compressor station, the fire was so bright that he had trouble seeing the road.\nHe then went to the pipeline on the west side of the Pecos River compressor station\nand began closing valves that were downstream from the fire. As he closed block (shutoff)\nvalve No. 6 3/4 on line 1100, the operations specialist who had telephoned him earlier\narrived, and the two men closed block valves No. 6 3/4 on lines 1103 and 1110. They also\nclosed the pig launcher valves on these pipelines.13\nThe pipeline lead operations specialist and the operations specialist then drove\ntheir trucks to the west side of the service bridge and viewed the fire across the river, but\n9 The Keystone compressor station, an attended station about 57 miles east and upstream of the Pecos\nRiver compressor station, supplied gas to the Pecos River compressor station through lines 1103 and 1110.\n10 The Eunice plant, an attended station about 53 miles northeast and upstream of the Pecos River River\nstation, supplied gas to the Pecos River compressor station through line 1100.\n11 The South Carlsbad compressor station, an attended station about 25 miles north and upstream of the\nPecos station, supplied gas to the Pecos River compressor station through line 3191.\n12 Notifying the public relations department, which was responsible for responding to inquiries\nregarding events involving the company, was part of EPNGís emergency response procedures.\n13 Pig refers to any of a variety of mechanical devices that can be introduced into a pipeline system\neither to clean the pipeline or, through use of various detection technologies, to identify possible pipeline\ndefects. Pig launchers and pig receivers in lines 1100, 1103, and 1110 at the time of the accident were used\nonly for cleaning pigs.\n\n<<<PAGE 16>>>\n\nFactual Information 8 Pipeline Accident Report\nthey could not determine which line had ruptured. The pipeline lead operations specialist\nsaid he then told the operations specialist to go around to the other side of the river and\nattempt to determine which line had failed.\nThe operations specialist said he drove across the river at the low-water crossing\nand viewed the scene, but because of the proximity of the lines to one another and the fire,\nhe could not determine which line had ruptured. The operations specialist said that as he\nwas returning to where he left the pipeline lead operations specialist, he thought he may\nhave seen vehicles in the fire area just south of the bridge. He continued back across the\nriver to assist the pipeline lead operations specialist and also told him about the possibility\nof vehicles in the fire area. The pipeline lead operations specialist said he told the\noperations specialist that they had to get the fire contained and that until that time, there\nwas nothing they could do. Both employees knew community emergency responders were\nwaiting at the entrance of the compressor station.\nThe two men then drove toward the low-water crossing, proceeding down the\nright-of-way road toward the fire. The pipeline lead operations specialist later recalled that\nwhen they arrived at the location where they were going to try to close the block valves\nupstream of the fire, he carefully opened the door of his truck to confirm that he could\ntolerate the heat. About 6:05 a.m., the two employees left their vehicles and proceeded to\nthe block valves. The pipeline lead operations specialist closed the No. 5 valve on line\n1100, but closing this valve did not reduce the intensity of the fire. Together they closed\nblock valve No. 6 on line 1103, and the operations specialist closed block valve No. 6 on\nline 1110. The fireís intensity was noticeably reduced after valve No. 6 on line 1103 was\nclosed, but the fire continued to burn at the lowered intensity. The pipeline lead operations\nspecialist told the operations specialist to check the bypass valve on the pig receiver14 on\nline 1103 and after it was closed, the fire subsided altogether over a period of several\nminutes. At about 6:21 a.m., the pipeline lead operations specialist called the gas control\ncenter and reported the status of the valves and that the fire was out.\nThe pipeline lead operations specialist then told the operations specialist to go\nback to the west side of the river and prevent traffic from entering the area. The operations\nspecialist said that as he passed where he thought he may have seen the vehicles during the\nfire, he now clearly saw burned pickup trucks. He stopped and called the pipeline lead\noperations specialist to tell him there were casualties. The pipeline lead operations\nspecialist then notified his supervisor and told him to call for more ambulances.\nThe operations specialist took a first-aid kit from his truck and started down on\nfoot to check on survivors. At this time, the station lead operations specialist pulled up\nbehind his truck. He knew where the operations specialist was because he had been\nmonitoring radio traffic. After the two men discussed the situation, the operations\nspecialist went to assist the victims while the station lead operations specialist drove back\nto where he knew fire and emergency medical personnel were waiting. He then led an\nambulance to the fire area. The pipeline lead operations specialist said he drove to the\n14 The pig receiver is an arrangement of pipe and valves connected to the pipeline that allows a pig to\nbe removed from the pipeline.\n\n<<<PAGE 17>>>\n\nFactual Information 9 Pipeline Accident Report\nlocation of the No. 6 3/4 block valves and, with the assistance of two other EPNG\nemployees, closed a valve that double-blocked line 1110 (to prevent gas from entering the\nstation in case one of the block valves on the line was leaking).\nThe station pipeline specialist had been called by the gas control center as soon as\nthe Pecos River compressor station shut down at about 5:30 a.m. to determine if the\nproblem was at the station. When he arrived at the entrance road to the compressor station\noff Whitethorn Road at about 6:10 a.m., he met the two operations specialists he had\ntelephoned earlier and saw the Loving Fire Department vehicles on Whitethorn Road at\nthe entrance driveway to the compressor station. He turned into the entrance road, entered\nthe compressor station, and went to the control room to inspect the equipment. He said he\nknew that power was off at the station because no lights were available in the control\nroom. He said that the automatic emergency shutdown system had vented gas from the\nstation, shut off electrical service, and started the battery-powered cool-down pumps on\nthe compressors. He and the two operations specialists then crossed the road to the 3191\nblock valve for the South Carlsbad line. This valve was just outside the east fence of the\ncompressor station where line 3191 connects to lines 1103 and 1110. They finished\nclosing the block valve at about 6:16 a.m., thereby isolating the South Carlsbad\ncompressor station from the Pecos River station and from lines 1103 and 1110. The station\nlead operations specialist telephoned the gas control center and informed personnel there\nthat the valve was closed and that the South Carlsbad compressor station should be taken\noff line. The station lead operations specialist sent the other two employees back to\nWhitethorn Road to help with crowd control as needed.\nAt about 5:51, the first emergency responders arrived on scene and staged on\nWhitethorn Road where the driveway into the Pecos River compressor station intersects\nthe road. Additional emergency responders also staged at this location, which is about 3/4\nmile from the accident site. The Carlsbad Fire Departmentís medic units had responded to\nthe initial call and proceeded as far as the Pecos River compressor station. They remained\nthere until an ambulance was directed to the victims and EPNG employees admitted the\nsmaller fire vehicles.15 When one of the fire engines entered the unpaved road from the\nwest during the fire before the No. 6 block valves were closed, the station lead pipeline\noperations specialist stopped them from going farther. He told fireman to stand by while\nhe shut more valves. As police cars arrived at that location, he told them to go back to the\nrailroad tracks and let only EPNG vehicles or vehicles with flashing red lights through.\nEmergency vehicles were admitted as needed to the accident scene after the fire at the\nruptured line was out.\nThe victims were camped about 675 feet from the crater, between the crater and\nthe river. Emergency personnel located victims with the assistance of the operations\nspecialist. Six victims were found at the camping area; six others had gone into the river\nand were either in the river or had been assisted to the banks by the operations specialist.\nParamedics and emergency medical technicians worked to treat the injuries. Volunteer\n15 The station lead operations specialist was concerned that the larger fire fighting equipment would\nbecome stuck on the sandy access road.\n\n<<<PAGE 18>>>\n\nFactual Information 10 Pipeline Accident Report\nfirefighters and the crews of Carlsbad medic units then evacuated the six victims to\nhospital burn centers in Texas. None of the victims survived.\nThe New Mexico State Police responded to the accident and assumed\nresponsibility for emergency management of the incident. Police personnel also provided\nsupport to Safety Board personnel during the on-scene investigation. EPNG reported the\naccident to the National Response Center at 8:27 a.m.\nPipeline Operations After the Rupture\nEPNG gas controllers called gas suppliers to inform them of the problem and to\nrequest that gas supplies into the affected part of the EPNG system be reduced or\nsuspended due to the incident and the ","truncated":true,"body_characters":163805}