Skip to content

Veolia Environmental Services Flammable Vapor Explosion and Fire

Overview

At about 12:07 a.m. on May 4, 2009, highly flammable vapor released from a waste recycling process at Veolia ES Technical Solutions, LLC in West Carrollton, Ohio ignited and violently exploded. The incident seriously injured two workers, injured two others, damaged eight structures at the plant, and caused damage to approximately 20 residences and businesses offsite.

Incident Snapshot

Field Value
Facility / Company Veolia ES Technical Solutions, LLC (Veolia Environmental Services North America Corp.)
Location West Carrollton, OH
Incident Date 05/04/2009
Investigation Status The CSB investigation was released on July 21, 2010.
Accident Type Flammable Vapor Explosion and Fire
Final Report Release Date 07/21/2010

What Happened

At about 12:07 a.m. on May 4, 2009, highly flammable vapor, released from a waste recycling process, ignited and violently exploded.

The unit operator had commenced the shutdown of a tetrahydrofuran (THF) solvent recovery process on Unit 3 when test results indicated that the material had reached the desired azeotropic state.

After completing the run, the Unit 3 shutdown process required clearing the pipe of remaining process materials by back-blowing nitrogen through the circulation piping into the dirty tank prior to closing valves to isolate the tank from the operating unit.

The vapor release occurred shortly after the unit operator started the flow of nitrogen back to the dirty tank.

Employees present at the time of the incident reported that, about two minutes before the explosion, they heard a loud vapor release.

Multiple explosions afterward significantly damaged every structure on the site.

The fire was declared under control by 10:38 a.m. that day.

Firefighters applied foam at about 10:00 a.m. the next day to extinguish the remaining fires in the dirty tank farm.

Facility and Process Context

The West Carrollton facility opened in 1979 as Solvent Resource Recovery and, after several name changes, became Chemical Waste Management (CWM) Resource Recovery in 1988.

On July 1, 2006 the site was renamed Veolia ES Technical Solutions, L.L.C. (VESTS)—a subsidiary of Veolia Environmental Services North America Corp. (VESNA).

The site was a state-permitted treatment, storage, and disposal facility (TSDF) that provided hazardous waste services for industrial and municipal customers.

The processing area consisted of two tank farms and three solvent recovery units.

The lab/operations building was a multi-use structure that served as the primary workstation for lab technicians, lab managers, production clerks, plant operators, and supervisors.

The building also housed a control room, break/dining area, laboratory, locker rooms, and three boilers.

The north wall of the lab/operations building was less than 30 feet from the operating units.

The administration building was located about 500 feet south of the operating plant and provided office and meeting space for plant management, technical, accounting, environmental health and safety, and other personnel.

Employees occupied a number of structures at the site depending on the time of day.

Consequences

  • Fatalities: 0
  • Injuries: Four workers injured; two employees were severely injured, one employee suffered first-degree burns and a second broke his pelvis, and two others were slightly injured.
  • Environmental release: Highly flammable vapor was released from a waste recycling process in the dirty tank farm; the EPA deployed a trailer to sample the air around the perimeter of the plant and found no hazardous concentrations of toxins.
  • Facility damage: Multiple explosions significantly damaged every structure on the site. Eight structures at the plant sustained damage. The explosion and fire damaged all buildings and operating units at the site, including the administration, drum storage, decant storage, maintenance, and non-hazardous waste processing buildings, and Units 1, 3 and 4. Several dirty tanks were destroyed, the tops of two stainless steel clean tanks blew off, and the water storage tank system failed to suppress the fires due to ruptured pipes.
  • Operational impact: The fire was declared under control by 10:38 a.m. that day. Firefighters applied foam at about 10:00 a.m. the next day to extinguish the remaining fires in the dirty tank farm.

Key Findings

Immediate Causes

  • highly flammable vapor, released from a waste recycling process, ignited and violently exploded
  • Uncontrolled venting of THF allowed flammable vapors to accumulate to explosive concentrations outside the process equipment, and the gas subsequently ignited

Contributing Factors

  • The vent devices were not designed to contain or control hazardous and/or toxic vapor.
  • Two natural gas-fired boilers were in service in the lab/operations building at the time of the incident and most likely provided the ignition source.
  • The lab/operations building, which housed the source of the ignition, was located about 30 feet south of the operating plant and served as a mixed-use structure, which was occupied primarily by non-essential personnel throughout the day shift.
  • The operating plant had an electrical classification of Class 1, Division 1 and was compliant with electrical code requirements. However, the lab/operations building was not classified under the National Electrical Code (NFPA 70).
  • No record existed of a process hazard analysis (PHA) to evaluate the siting of the lab/operations building so close to the operating units.
  • Once the unit operator discovered the release, he began efforts to mitigate the leak by approaching shut-off valves located in the plant, but could not because of the overpowering odor of the released material.
  • Considerable congestion and confinement was created by tanks, pumps, and related equipment.
  • The materials processed at the West Carrollton facility sometimes had the potential for chemical reaction.

Organizational and Systemic Factors

  • The company failed to conduct compliance audits every three years to ensure that policies and procedures were in place for the handling of flammable liquids.
  • Worker training deficiencies were cited.
  • Inadequate testing and inspections of piping and processes were cited.
  • There was a lack of written standards for operating procedures.
  • There was a lack of written standards for maintaining mechanical integrity of equipment.
  • Precautions for peroxide formation were not included in the Unit 3 operating procedure.
  • The unit operator was advised to continue operating Unit 3 as outlined in the operating plan unless the pump was disrupting plant operation.
  • Veolia never conducted a process hazard analysis for the siting of the lab/operations building so close to the operating units.
  • OSHA's post incident inspection cited the company for not evaluating facility siting.

Failed Safeguards or Barrier Breakdowns

  • The vent devices were not designed to contain or control hazardous and/or toxic vapor.
  • The water storage tank intended for use during a fire, which normally contains about 500,000 gallons of water, was rendered inoperative due to ruptured pipes.
  • The system failed to suppress the fires.
  • The lab/operations building was not classified under the National Electrical Code (NFPA 70).
  • No record existed of a process hazard analysis (PHA) to evaluate the siting of the lab/operations building so close to the operating units.
  • Precautions for peroxide formation were not included in the Unit 3 operating procedure.
  • The unit operator could not approach shut-off valves because of the overpowering odor of the released material.

Recommendations

  1. 2009-10-I-OH-R1 | Recipient: Veolia ES Technical Solutions | Status: Closed-Acceptable Action | During the rebuild of the plant, revise policy to restrict occupancy of non-essential personnel in buildings in close proximity to operating plants.
  2. 2009-10-I-OH-R2 | Recipient: Veolia Environmental Services Technical Solutions LLC | Status: Closed – Reconsidered/Superseded | During the rebuild, design and install a closed relief system and develop a policy for safe venting (e.g., use of a flare) for relief systems to the atmosphere.
  3. 2009-10-I-OH-R3 | Recipient: Veolia ES Technical Solutions | Status: Closed-Acceptable Action | Conduct a process hazard analysis on all OSHA Process Safety Management covered processes to ensure all buildings and structures at the West Carrollton facility are located and designed in accordance with electrical classification and spacing as defined in NFPA 70.
  4. 2009-10-I-OH-R4 | Recipient: National Fire Protection Association (NFPA) | Status: Closed – Acceptable Action | Revise NFPA 30, Chapter 17, to include a section requiring a written engineering analysis to determine the safe separation distance for occupied buildings, control rooms, and operating areas. The analysis must be acceptable to the authority having jurisdiction.
  5. 2009-10-I-OH-R5 | Recipient: Center for Chemical Process Safety | Status: Closed-Acceptable Action | Revise control room siting guidelines to reflect the diversity of characteristics that Class 1B flammable liquids can exhibit (e.g., heavy vapor, and plant areas that provide congestion and confinement).
  6. 2009-10-I-OH-R6 | Recipient: Environmental Technology Council (ETC) | Status: Closed—Acceptable Alternative Action | Petition the National Fire Protection Association, following the guidelines of their "Codes and Standards Development Process" (www.nfpa.org), to develop an occupancy standard specific to hazardous waste treatment, storage, and disposal facilities. The purpose of the standard would be to prescribe technical requirements for the safety to life and property from fire, explosion, and release; and to minimize the resulting damage from a fire, explosion, and release. At a minimum, but not limited to, the standard should address: Hazard Identification; Chemical Fire and Release Protection and Prevention; Facility and Systems Design; Employee Training and Procedures; Inspection and Maintenance.
  7. 2009-10-I-OH-R7 | Recipient: Environmental Technology Council (ETC) | Status: Closed – Acceptable Action | Develop and issue standardized guidance for the processing, handling and storage of hazardous waste to reduce the likelihood of fires, explosions, and releases at hazardous waste treatment storage and disposal facilities. Include the incident findings, consequences, conclusions, and recommendations from the CSB investigations of the Environmental Quality facility and the Veolia ES Technical Solutions.

Key Engineering Lessons

  • Relief devices and vent systems should be designed to contain or control hazardous and/or toxic vapor rather than allow uncontrolled venting to atmosphere.
  • Building siting for occupied structures near process areas should be based on a written engineering analysis that considers chemical properties, quantities, congestion, confinement, and ignition sources.
  • Electrical classification and spacing requirements must be evaluated for buildings and structures near flammable process areas, including mixed-use buildings with non-essential personnel.
  • Process hazard analysis should be performed for siting decisions affecting occupied buildings and operating units.
  • Operating procedures for THF recovery should include precautions for peroxide formation where applicable.

Source Notes

  • Priority 1 final report used as the primary authority for incident facts, causes, consequences, and recommendations.
  • Recommendation status changes from later documents were used to update recommendation statuses where explicitly stated.
  • Where documents differed on wording, the final report terminology was preserved when possible and later recommendation documents were used only for status updates and recommendation text confirmation.
  • No external facts were added beyond the provided extracts.

Similar Incidents

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

Same Equipment

Same Root Cause

Same Hazard

← View in Knowledge Graph