Skip to content

BLSR Operating Ltd. Vapor Cloud Fire

Overview

On January 13, 2003, a vapor cloud fire occurred at the BLSR Operating, Ltd. oilfield waste disposal facility near Rosharon, Texas. Two vacuum trucks were unloading basic sediment and water (BS&W) into an open area collection pit and mud disposal and washout pad. The fire killed 3 workers and injured 4 others. The final report concluded that hydrocarbon vapor released during unloading was ignited most likely by backfiring from a truck diesel engine.

Incident Snapshot

Field Value
Facility / Company BLSR Operating, Ltd.
Location Rosharon, TX
Incident Date 2003-01-13
Investigation Status Final report approved on September 17, 2003.
Accident Type Vapor cloud deflagration and fire
Final Report Release Date 2003-09-17

What Happened

  • At approximately 4:00 pm on January 13, 2003, the drivers of T&L trucks #1004 and #1003 collected BS&W from the CJ Waller and Roberts lease site condensate storage tanks, respectively.
  • The trucks arrived at BLSR within a few minutes of each other.
  • Each driver backed onto the mud disposal and washout pad to unload BS&W and have the truck tanks rinsed out.
  • The two drivers exited the trucks, left the engines running, informed BLSR employees that the trucks were to be drained and rinsed out, and made their way to the drivers’ shed to complete paperwork and wait for the washout to be completed.
  • Two BLSR employees opened the valves to drain the truck tanks.
  • One BLSR employee climbed onto the truck parked on the north side of the pad and began to remove the manway cover bolts in preparation for the washout.
  • As reported by eyewitnesses, the trucks were in position for 3 to 5 minutes when the truck engine on the north side began to violently race/rev, slowed, and then violently raced again, blowing thick black smoke from the exhaust stack.
  • BLSR employees and the driver of the north truck reported that they heard loud backfiring.
  • The second (south) truck engine began the same violent racing.
  • At this point, a deflagration occurred.
  • The two trucks were completely engulfed by fire, as was the west end of the pit containing the liquid that had drained from the trucks.
  • One of them placed a call to 9-1-1 at 4:36 pm.
  • Angleton Emergency Medical Services (EMS) and the Rosharon VFD arrived on scene at 4:50 pm.
  • The fire was brought under control at 5:35 pm.
  • Emergency responders completed their work at 10:00 pm.

Facility and Process Context

  • The BLSR facility is located 5 miles north of Rosharon, Texas, on FM521.
  • BLSR employed 18 personnel.
  • The facility has been in operation since the mid 1980s and is currently permitted by RRC to operate five U.S. Environmental Protection Agency (EPA) Class II waste liquid injection wells.
  • It operates on a 24-hour/day, 7-day/week schedule.
  • The BLSR disposal facility contains two waste liquid unloading stations—the saltwater disposal station and the mud disposal and washout pad.
  • The mud disposal and washout pad was designed and built for unloading high-viscosity drilling mud and other waste liquids heavily contaminated with sand and other materials, and for rinsing out empty vacuum truck tanks with high-pressure freshwater.
  • There are no provisions for recovering condensate/crude oil from the waste liquid that is unloaded onto the pad.
  • A corrugated roof canopy, approximately 17 feet high, covers the pad.
  • A 220-volt electrical service feed and circuit breaker box are attached to the southwest canopy support.
  • With the exception of the droplights, none of the electrical conduits, fixtures, or boxes were certified for use in a flammable environment.
  • BLSR management had no written procedures for truck unloading, operation of systems, or emergency response.
  • Employees learned their tasks exclusively through on-the-job training by BLSR management and experienced workers.

Consequences

  • Fatalities: 3 killed
  • Injuries: 4 injured
  • Environmental release: There was no environmental damage.
  • Facility damage: The fire destroyed two 50-barrel (2,100-gallon) vacuum trucks and seriously damaged waste liquid offloading equipment and structures at BLSR. The canopy above the unloading pad sustained major heat damage. The electrical service line attached to the southwest canopy support column was severed, and all ceiling-mounted lighting and the vent fan were destroyed. The emergency eyewash station and shower next to the drivers’ shed, the equipment switch panel on the northwest corner wall adjacent to the concrete pad, and equipment in the electrical shed sustained significant radiant heat damage. Fire and smoke damaged the storage room attached to the drivers’ shed.
  • Operational impact: Emergency responders completed their work at 10:00 pm. The fire destroyed two vacuum trucks and heavily damaged equipment and structures in and around the BLSR unloading pad.

Key Findings

Immediate Causes

  • The fire was caused by the release of hydrocarbon vapor during the unloading of BS&W from two vacuum trucks into an open area collection pit.
  • CSB determined that the T&L trucks were in the process of offloading BS&W onto the concrete pad when the deflagration occurred.
  • CSB determined that backfiring from the south engine is the most likely source of ignition of the flammable vapor cloud.

Contributing Factors

  • T&L employees did not understand the potential flammability hazard of BS&W in the product storage tank, nor did they understand that inadvertent mixing of hydrocarbon product with waste liquid when filling the vacuum truck tank most likely increased the flammability hazard of the truck contents.
  • T&L and BLSR management did not implement safe work practices to minimize the generation of flammable vapor and to control ignition sources.
  • Neither T&L nor BLSR management and employees recognized that the truck diesel engines presented multiple vapor ignition sources.
  • The flammability hazard is dependent on the source of the liquid, ambient temperature, mixing during transfer to the vacuum truck, and other process variables.
  • The actual flammability hazard of BS&W and other waste liquids was not recognized by many personnel in the E&P industry.
  • The T&L truck engines were not equipped with overspeed protection devices in the intake or exhaust systems.
  • Because the trucks were not grounded, unloading of the tank contents may have generated a static electric spark, which could have ignited the flammable vapor.
  • None of the circuits were designed for operation in a flammable vapor environment.

Organizational and Systemic Factors

  • Noble Energy, Inc., the shipper, failed to identify the flammability hazard of BS&W generated at its gas well production facility, and also failed to communicate the hazard to employees and contractors who were required to handle the flammable liquid.
  • T&L management did not require Noble Energy to provide vacuum truck drivers with a material safety data sheet or other document listing the potential flammability hazard of BS&W, nor did it identify the flammability hazard of the mixture in the vacuum truck tank.
  • BLSR management did not have effective hazard communication practices in place to recognize the potential flammability hazard of each shipment of BS&W, nor did it implement safe handling practices when offloading flammable liquid onto the mud disposal and washout pad area.
  • BLSR management had no written procedures for truck unloading, operation of systems, or emergency response.
  • BLSR relied on the truck drivers to decide which of the two unloading systems to use.
  • T&L management did not recognize that the process of unloading BS&W from the storage tank is likely to increase its flammability due to the unavoidable removal of highly flammable condensate along with BS&W.
  • BLSR management did not use available industry guidelines (such as those contained in API Order No. G00004, Guidelines for Commercial Exploration and Production Waste Management Facilities) to establish procedures for properly identifying waste liquids and their associated flammability hazards.
  • T&L and BLSR management failed to train their employees on diesel engine overspeed as an indication of the presence of a highly flammable vapor.

Failed Safeguards or Barrier Breakdowns

  • The required MSDS was not provided to the vacuum truck drivers.
  • Condensate storage tanks were not labeled with hazard information.
  • BLSR did not review shipping papers or conduct flammability tests to determine the flammability hazard of delivered waste liquids before offloading.
  • BLSR provided no means of grounding the vacuum truck on the waste disposal pad, an important safety precaution to reduce the possibility of static discharge.
  • BLSR unloading methods did not minimize or control the generation of flammable vapor during the offloading of BS&W; there was no effort to avoid uncontrolled splashing onto the open concrete pad.
  • T&L treated all waste liquid as nonflammable, as reported by management and evidenced by the use of non-DOT certified vacuum truck tanks.
  • T&L did not inform the drivers that BS&W could present a significant flammability hazard, requiring special handling precautions, such as ensuring that the truck engine was upwind and far enough away to preclude contact with a flammable vapor source.
  • There were no emergency procedures for safe and proper response to diesel engine overspeed.
  • The truck drivers and at least one of the BLSR employees responded to the diesel engine malfunction by moving closer to the trucks.
  • None of the electrical conduits, fixtures, or boxes were certified for use in a flammable environment.

Recommendations

  1. 2003-06-I-TX-R1 — Recipient: Noble Energy, Inc. — Status: Not specified — Provide documentation of the potential flammability hazard of exploration and production (E&P) waste liquids—such as a material safety data sheet (MSDS)—to all employees, contract personnel, and haulers handling waste liquids generated at well sites. Emphasize that mixing condensate with basic sediment and water (BS&W) during the removal process can significantly increase the flammability hazard. The mixture in the transport container should be treated as a flammable liquid absent positive identification to the contrary.
  2. 2003-06-I-TX-R2 — Recipient: Noble Energy, Inc. — Status: Not specified — Review and revise company gauging and waste liquid removal protocols as necessary to minimize the inadvertent removal and subsequent disposal of hydrocarbon product when removing BS&W from product storage tanks.
  3. 2003-06-I-TX-R3 — Recipient: T&L Environmental Services, Inc. — Status: Not specified — Ensure that the written procedures for hazard identification require that all customers requesting loading and transportation of exploration and production (E&P) waste liquids provide written notification, such as a material safety data sheet (MSDS), listing the potential flammability hazard.
  4. 2003-06-I-TX-R4 — Recipient: T&L Environmental Services, Inc. — Status: Not specified — Ensure that the written procedures for safe operation of vacuum trucks incorporate applicable good practices, including techniques to minimize the possibility of exposing the diesel engine to flammable vapor, as provided in API RP-2219, Guidelines for Commercial Exploration and Production Waste Management Facilities.
  5. 2003-06-I-TX-R5 — Recipient: T&L Environmental Services, Inc. — Status: Not specified — Develop written operating procedures that incorporate best practices for unloading storage tank waste liquids, such that drivers accurately measure the quantity of liquid removed from the storage tank and minimize removal of product, such as flammable condensate.
  6. 2003-06-I-TX-R6 — Recipient: T&L Environmental Services, Inc. — Status: Not specified — Ensure that written emergency procedures address the safe response to abnormal diesel engine operation due to a flammable vapor atmosphere. Explain that the normal engine shutoff method will not function as long as flammable vapor continues to enter the intake system.
  7. 2003-06-I-TX-R7 — Recipient: T&L Environmental Services, Inc. — Status: Not specified — Conduct and document training for all personnel who handle waste liquids, using languages or formats that are clearly understood by all affected personnel. Address the potential flammability hazard associated with E&P waste liquids, emphasizing how the withdrawal procedure is likely to increase the flammability of the vacuum truck contents through unavoidable mixing of product and basic sediment and water (BS&W). Describe operating and emergency response to diesel engine overspeed caused by a flammable vapor atmosphere.
  8. 2003-06-I-TX-R8 — Recipient: BLSR Operating, Ltd. — Status: Not specified — Develop a written Waste Acceptance Plan as recommended by API Order No. G00004, Guidelines for Commercial Exploration and Production Waste Management Facilities. Require the shipper or carrier to properly classify the flammability hazard of exploration and production (E&P) waste liquids. Require the hauler to provide information that identifies the flammability hazard of the material before accepting the load, such as a material safety data sheet (MSDS).
  9. 2003-06-I-TX-R9 — Recipient: BLSR Operating, Ltd. — Status: Not specified — Develop and implement written procedures and provide training to employees on the safe handling of all waste liquids delivered to the facility in accordance with API Order No. G00004, Guidelines for Commercial Exploration and Production Waste Management Facilities; and API RP-2219, Safe Operation of Vacuum Trucks in Petroleum Service. Include requirements for proper grounding of trucks and eliminating other sources of ignition (e.g., facility electrical equipment and smoking in unloading areas). Ensure that the material is presented in languages or formats that are clearly understood by all affected personnel.
  10. 2003-06-I-TX-R10 — Recipient: BLSR Operating, Ltd. — Status: Not specified — Develop written procedures and provide training to employees on unloading all flammable or potentially flammable E&P waste liquids. Avoid unloading flammable liquids onto an open work area, such as the mud disposal and washout pad. Include alternative unloading method(s), such as using a closed piping system to minimize vapor generation. Ensure that the material is presented in languages or formats that are clearly understood by all affected personnel.
  11. 2003-06-I-TX-R11 — Recipient: BLSR Operating, Ltd. — Status: Not specified — Develop written emergency procedures and provide training to employees on response to abnormal or emergency situations, including uncontrolled flammable vapor releases that can result in a fire or explosion hazard. Ensure that the material is presented in languages or formats that are clearly understood by all affected personnel.
  12. 2003-06-I-TX-R12 — Recipient: U.S. Department of Transportation — Status: Not specified — Publish an information document for exploration and production (E&P) industry employers (including producers/shippers/offerors, motor carriers, and disposal facility operators) involved in the transportation of basic sediment and water (BS&W) and other E&P waste liquids on public highways. Emphasize the importance of, and responsibility for, properly classifying and identifying flammable waste liquids. Reference the Occupational Safety and Health Administration (OSHA) requirements for obtaining material safety data sheets (MSDS) from the shipper and the required content of DOT shipping papers. Include specific reference to this CSB Investigation Report and the American Petroleum Institute (API) recommended practices cited in this report.
  13. 2003-06-I-TX-R13 — Recipient: Occupational Safety and Health Administration (OSHA) — Status: Not specified — Issue a Safety and Health Information Bulletin on the potential flammability hazard associated with bulk transportation of oilfield exploration and production (E&P) waste liquids. Summarize OSHA requirements for proper hazard classification by the shipper and for the use of material safety data sheets (MSDS). Summarize U.S. Department of Transportation (DOT) requirements for proper hazard classification and manifesting of flammable liquids, approved container design, and periodic testing. Discuss safe handling to minimize the generation of flammable vapor and to control ignition sources from vehicle-mounted equipment and facility equipment. Discuss the need for the employer to provide all worker safety information in languages or formats that are clearly understood by all affected personnel. Summarize the requirements for proper labeling of storage tanks to clearly identify the hazard of the contents to all employees and contractors working at the well site.
  14. 2003-06-I-TX-R14 — Recipient: Texas Railroad Commission (RRC) — Status: Not specified — Require that all permitted drillers and producers identify and document (e.g., material safety data sheet [MSDS]) the potential flammability hazard of exploration and production (E&P) waste liquids. Provide the information to workers and contractors in languages clearly understood by the recipients.
  15. 2003-06-I-TX-R15 — Recipient: Texas Railroad Commission (RRC) — Status: Not specified — Provide information (e.g., safety bulletin) to industry on the potential flammability hazard associated with basic sediment and water (BS&W) and other E&P waste liquids. Waste liquids can contain sufficient hydrocarbons to be classified as flammable liquids. The waste liquid removal method can result in removing significant quantities of flammable hydrocarbon product such that the mixture in the transport container may require classification as a flammable liquid under Occupational Safety and Health Administration (OSHA) or U.S. Department of Transportation (DOT) regulations.
  16. 2003-06-I-TX-R16 — Recipient: American Petroleum Institute (API) — Status: Not specified — Revise API RP-2219, Safe Operation of Vacuum Trucks in Petroleum Service, and API Order No. G00004, Guidelines for Commercial Exploration and Production Waste Management Facilities, to discuss the hazards of unloading potentially flammable or flammable liquids onto an open unloading area, such as a concrete pad. Recommend other alternatives for minimizing vapor generation, such as unloading of flammable liquids into a closed piping system.
  17. 2003-06-I-TX-R17 — Recipient: American Petroleum Institute (API) — Status: Not specified — Communicate the findings and recommendations of this report to your membership. Emphasize that basic sediment and water (BS&W) removed from crude oil and condensate storage tanks requires special handling, in addition to compliance with Occupational Safety and Health Administration (OSHA) or U.S. Department of Transportation (DOT) regulations, if it contains sufficient hydrocarbons (either residual or mixed in during the removal process) to be classified a flammable liquid as defined by each regulation.
  18. 2003-06-I-TX-R18 — Recipient: National Tank Truck Carriers, Inc. — Status: Not specified — Communicate the findings and recommendations of this report to your membership. Emphasize emergency response to diesel engine overspeed caused by exposure to flammable vapor atmospheres.

Key Engineering Lessons

  • Unloading potentially flammable E&P waste liquids onto an open area collection pit or concrete pad can allow flammable vapor generation and deflagration.
  • Vacuum truck diesel engines can become ignition sources in a flammable vapor atmosphere, including through backfiring and overspeed/racing behavior.
  • Grounding provisions are an important safeguard where static discharge could ignite vapors during unloading.
  • Closed piping systems and other methods that minimize vapor generation are preferred over open unloading areas for flammable or potentially flammable liquids.
  • Hazard identification and acceptance controls must be in place before unloading BS&W, including written notification such as an MSDS and proper classification of the waste liquid.

Source Notes

  • Priority 1 final report content was used to resolve conflicts where later supporting documents contained differing counts, wording, or incident framing.
  • The final report states 3 killed and 4 injured; some supporting documents describe the incident differently or with incomplete counts, but were not used to override the final report.
  • The final report identifies the most likely ignition source as backfiring from the south engine.
  • The final report and supporting documents consistently identify the release of hydrocarbon vapor during unloading of BS&W into an open area collection pit / mud disposal and washout pad as the initiating event.
  • Recommendations were consolidated from the final report; duplicate or paraphrased versions in other documents were not added separately.

Similar Incidents

Incidents sharing the same equipment, root causes, or hazard types.

Same Equipment

Same Root Cause

Same Hazard

← View in Knowledge Graph