Denton Recycle Center - Executive Summary
EXECUTIVE SUMMARY |
Accidental Release Prevention and Emergency Response Policies
Safety-Kleen Systems, Inc.'s (Safety-Kleen) Denton Recycle Center is committed to both worker and public safety. This commitment has been implemented through an investment of resources and time developing the process safety management and accident prevention programs. The programs emphasize essential elements such as training personnel, considering safety aspects of installing new equipment, preparing operating procedures that minimize accidents, and performing maintenance on process equipment throughout the facility. Safety-Kleen has identified the most likely situations where an accident would occur and has developed safety and prevention procedures to avoid them. In the event that a release does occur, Safety-Kleen has trained its personnel to respond to and contain the release, or coordinate with the appropriate agencies to minimize on-site and offsite impacts.
Description of a Stationary Sourc
e and Regulated Substances
Safety-Kleen's Denton Recycle Center is located in the City of Denton, Texas, and operates a spent solvent recycling operation. Processes include receiving spent organic chemicals from other Safety-Kleen facilities or from industrial or commercial customers. The material is received by bulk tanker trucks or in 5 to 55-gallon containers and transferred to storage vessels prior to handling. The spent mixtures are recycled through the use of distillation, fractionation, drying, liquid-to-liquid extraction, and evaporation techniques. Reclaimed or reprocessed solvents are then transported offsite via bulk tanker trucks or in 5 to 55-gallon containers. Safety-Kleen has reviewed the list of RMP-regulated substances and their threshold quantities and has determined that they may potentially hold these substances on-site. Therefore, Safety-Kleen is predictively filing this risk management plan.
Worst-Case Release Scenario
Both the worst-case toxic and flamma
ble releases were administratively limited to allowable weight percents of substances that Safety-Kleen will accept at its facility. This mechanism is implemented through Safety-Kleen's acceptance guidance document that identifies compounds and their acceptable concentration before Safety-Kleen will receive them.
The worst-case scenario for toxics is a release from a tank truck cargo vessel containing 6,000 gallons of a chemical mixture including 38% hydrochloric acid. Safety-Kleen will accept mixtures containing hydrochloric acid in quantities less than 38% by weight; therefore, the vessel contained a maximum of 2280 gallons hydrochloric acid. The release formed a liquid pool of hydrochloric acid with a surface area of 9378 ft2 around the storage container area. The Areal Locations of Hazardous Atmospheres (ALOHA) dispersion model was used to predict the distance to toxic endpoint. The model predicted the distance to toxic endpoint would be 3.6 miles.
The facility does not handl
e any of the regulated flammable substances in quantities greater than the Part 68 thresholds. Therefore, a worst-case scenario for flammable substances was not completed.
Alternate Release Scenario for Toxic Liquid
The alternate release scenario for vinyl acetate is the release of a mixture containing 50% vinyl acetate from overfilling a storage vessel in the containment area of Tank Farm No. 1. Safety-Kleen uses 1) administrative controls to limit vinyl acetate to concentrations less than 50% by weight, and 2) multiple levels of process safety management to prevent overfilling (i.e. visual tank level inspection and electronic monitoring and alarm system). A tank overfill would be detected and corrective action taken in less than 10 minutes. The ALOHA dispersion model was used to predict the distance to endpoint, which was 0.96 miles.
The alternate release scenario for chlorine is the release of a mixture containing 1% chlorine from overfilling a storage vessel in the containmen
t area of Tank Farm No. 1. Safety-Kleen uses 1) administrative controls to limit the concentration of chlorine to 1%, and 2) multiple levels of process safety management to prevent overfilling (i.e. visual tank level inspection and electronic monitoring and alarm system). A tank overfill would be detected and corrective action taken in less than 10 minutes. The ALOHA dispersion model was used to predict the distance to toxic endpoint, which was 1.3 miles.
The alternate release scenario for ammonia is the release of a mixture containing 30% ammonia from overfilling a storage vessel in the containment area of Tank Farm No. 1. Safety-Kleen uses 1) administrative controls to limit the concentration of ammonia to 30%, and 2) multiple levels of process safety management to prevent overfilling (i.e. visual tank level inspection and electronic monitoring and alarm system). A tank overfill would be detected and corrective action taken in less than 10 minutes. The ALOHA dispersion model w
as used to predict the distance to toxic endpoint, which was 0.53 miles
The alternate release scenario for methytrichlorosilane is the release of a mixture containing 2% methytrichlorosilane from overfilling a storage vessel in the containment area of Tank Farm No. 1. Safety-Kleen uses 1) administrative controls to limit the concentration of methytrichlorosilane to 2%, and 2) multiple levels of process safety management to prevent overfilling (i.e. visual tank level inspection and electronic monitoring and alarm system). A tank overfill would be detected and corrective action taken in less than 10 minutes. The ALOHA dispersion model was used to predict the distance to toxic endpoint, which was 0.19 miles.
The alternate release scenario for hydrochloric acid is the release of a mixture containing water and 38% hydrochloric acid from a leaking cargo vessel onto the concrete storage pad of a container storage area. The release rate was estimated at 10 gallons per minute for ten minu
tes, for a total of 100 gallons of water and 38% hydrochloric acid. The ALOHA dispersion model was used to predict the distance to toxic endpoint, which was 0.76 miles.
The facility does not handle any of the regulated flammable substances in quantities greater than the Part 68 thresholds. Therefore, an alternate release scenario for flammable substances was not completed.
General Accidental Release Prevention Program and Chemical-Specific Prevention Steps
The Denton Recycle Center is subject to the OSHA PSM standard and has developed a prevention program to ensure that the facility treats, stores, and disposes hazardous waste in the safest possible manner. The following is an overview of the OSHA PSM elements that have been incorporated into the RMP prevention program.
Process Safety Information
Safety-Kleen maintains technical documentation to assist its personnel with the safe operation and maintenance of its PSM processes. The documentation addresses the process technolog
y, chemical properties and hazards of the process, unique construction considerations, along with the design and use of safety mechanisms for specific equipment. Process safety information for each process is maintained at specific locations near the process it identifies.
Safety-Kleen maintains written operating procedures that address the various process modes of the operation such as startup, normal and temporary operation, emergency shutdown, normal shutdown, and initial startup of a process. These procedures can be referenced by trained operators and provide the basis for consistent and safe operation of the equipment. The operating procedures are accurate and are kept current by revising them through the management of change process as necessary.
Safety-Kleen has a comprehensive training program that includes training for operating the process equipment. In addition, employees are trained on the awareness and use of the hazardous materials ha
ndled at the facility and the proper handling techniques and hazards associated with handling them. Refresher training is done annually and includes training on the operation of emergency and safety equipment, locations of emergency equipment and alarms, and other information contained in the contingency plan. Finally, new employees undergo comprehensive training, including emergency training, before they assume their duties.
Safety-Kleen has established good working practices and procedures to maintain its storage vessels, piping systems, relief vent systems, process controls, pumps and compressors, and emergency shutdown systems in a safe operating condition. Maintenance personnel are trained on the specific processes that they operate. Training includes awareness of process hazards and the appropriate maintenance procedures to perform on the equipment. Equipment inspections and tests are performed on a regular schedule to verify that the equipment is with
in acceptable engineering standards and that the process equipment will operate safely.
Management of Change
Safety-Kleen has developed a system to manage changes to its processes. The management of change (MOC) program is implemented through an internal form (checklist) that ensures changes to the process equipment, chemicals processed, process technology, and operating procedures are properly reviewed and authorized before the change is implemented. The MOC system ensures that adequate controls are in place to manage any new safety concerns or hazards from the change and verifies that the existing system and its controls have not been altered or affected by the change. In addition, the MOC program verifies any operating limits and new chemical hazards are updated in accordance with the changes made to the processes. Finally, the MOC system ensures that operating and maintenance personnel are trained and knowledgeable of the changes to the process.
Pre-startup Safety Reviews
afety-Kleen conducts pre-startup safety reviews for any modification of a process that requires changes to process safety information. This ensures that the safety mechanisms, procedures, and personnel who operate the equipment are informed and prepared for the startup before the equipment is placed into service. Pre-startup safety reviews are implemented through checklists that verify all aspects of the startup mode.
Safety-Kleen's accident prevention program includes compliance audits, which are periodically conducted to determine if the facility's procedures and practices are adequately implemented. Compliance audits are conducted every three years, and are performed by an audit team consisting of consultants and Safety-Kleen personnel. The audit team performs a review and presents the findings in a report that is submitted to the facility for resolution. Corrective actions in response to the audit team's report are tracked until they are completed.
Safety-Kleen investigates all incidents that result in (or reasonably could have resulted in) a fire, explosion, or hazardous release that causes on and offsite property or environmental damage, or personal injury. The investigation process is designed to identify the circumstances prior to the incident, along with the corrective actions necessary to prevent a recurrence of the incident. The incident is documented with its findings and recommendations. In addition, Safety-Kleen uses a tracking mechanism to ensure that recommendations are followed. Once the findings and recommendations are resolved, a report is completed and maintained on-site and available for review by Safety-Kleen personnel.
Safety-Kleen encourages employee participation at every level of process safety management and the accident prevention program. For example, employees are encouraged to develop safety documentation and participate in a prevention program (i.e. team me
mbers of the process hazard analysis team). Safety-Kleen has provided employees access to all information regarding these programs and has encouraged employee participation by inviting various areas of the facility including operations, maintenance, engineering and management to process safety management meetings.
Safety-Kleen uses contractors to perform additional work at its facility. The contractors work on or near process equipment; therefore, Safety-Kleen has developed procedures to ensure the contractors perform work in the safest manner. The procedures also ensure the contractors have the appropriate technical knowledge and skills to work on Safety-Kleen's processes, are aware of the specific hazards, and understand the emergency procedures. Safety-Kleen trains contractors on site-specific rules, and provides a mechanism for them to inform Safety-Kleen of any hazards discovered while performing their work. This is accomplished through training provided by the
health and safety manager prior to contractors performing any work at the facility.
Chemical-Specific Prevention Steps
The Denton Recycle Center has additional safety features throughout the facility that assist in detecting and mitigating accidents at the facility. The systems mitigate accidental releases by containing and controlling the release, detecting the release early, or reducing the impact from the release. The following types of safety mechanisms are used throughout the facility:
7 Process relief valves discharging to the flare
7 Shutoff valves to permit isolation of a process
7 Dedicated vessels to allow partial removal of a process in the event of a release
7 Dikes to mitigate and contain liquid spills
7 Un-interruptible power for process control and fire suppression systems
7 Atmospheric relief devices
7 Audible alarms for overfilling of storage vessels
7 Fire suppression and extinguishing systems
7 Emergency response training for personnel
7 Protective equipment (
i.e. clothing, self-contained breathing apparatus) to allow personnel to mitigate a spill
7 Process isolation to protect other processes and personnel in the event of an accidental release
Five-Year Accident History
Safety-Kleen's Denton Recycle Center has had an excellent record of accident prevention over the past five years.
Emergency Response Program
The Denton Recycle Center maintains an emergency action plan (contingency plan) on-site that is accessible to all employees and visitors. The contingency plan is a detailed description of the procedures in place to minimize the effects of an emergency or an accidental release. The plan provides response procedures to be implemented during emergencies to minimize the hazards to human health or the environment from fires, explosions, unplanned sudden releases of hazardous waste or hazardous constituents to the air, soil, or water.
The contingency plan identifies the emergency response coordinator and contains detailed instructions
to be followed in the event of an emergency or accidental release. The emergency response procedures are outlined, such as notification and identification of a release, an assessment of the release (i.e. possible hazards to human health or the environment), and a determination of whether to include local emergency response teams. The plan includes emergency spill procedures, location and use of emergency equipment, recordkeeping and reporting procedures for incident reporting, and follow-up actions. The contingency plan also includes preparedness and hazard communication procedures to ensure that recycle center personnel are prepared to respond to emergency situations.
Finally, the plan includes the names and telephone numbers for the fire department, police department, local emergency planning committee, national response center, Texas Natural Resources Conservation Commission, and the local medical centers. The plan outlines the arrangements that have been made with these agenci
es to familiarize them with facility operations and layout (entrances, exits, evacuation routes), and the types of materials handled at Safety-Kleen. The plan also outlines the arrangements made with local hospitals such as identifying the types of hazardous waste that are handled and the types of injuries or illnesses that could be expected from an incident at the facility.