Mermentau Facility - Executive Summary

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LDEQ Facility ID 9681 
 
Mermentau Facility Risk Management Plan:  Executive Summary 
 
ACCIDENTAL RELEASE PREVENTION AND RESPONSE POLICIES 
 
The TransCanada Gas Processing USA Inc. (TransCanada) Mermentau Facility has a long-standing commitment to worker and public safety. This commitment is demonstrated by the resources invested in accident prevention, such as training personnel and considering safety in the design, installation, operation, and maintenance of facility's processes.  The TransCanada policy is to implement reasonable controls to prevent foreseeable releases of substances. However, if a release does occur, trained personnel will respond to, control, and contain the release. 
 
DESCRIPTION OF THE STATIONARY SOURCE AND REGULATED SUBSTANCES 
 
TransCanada owns and operates the Mermentau Facility located in Jefferson Davis Parish, Louisiana. The Mermentau Facility is a barge loading facility capable of storing and loading natural gasoline and butanes pipelined to the site. 
 
The Merme 
ntau Facility was evaluated to determine if any regulated flammable or toxic substances exceeded the threshold quantity.  Based on process knowledge, TransCanada identified the regulated substances and quantities kept on site.  Listed flammable substances which are stored above threshold quantities at the Mermentau Facility are natural gasoline, isobutane and n-butane.  There are no listed toxic substances which exceed threshold quantity. 
 
TransCanada has determined that natural gasoline has an National Fire Protection Association (NFPA) flammability hazard rating of 3, which exempts this mixture from threshold determination.  Based on worst-case analysis of flammables, the distance to the endpoint exceeds the distance to public receptors.  However, the Mermentau Facility is subject to a portion of the Occupational Safety and Health Administration's (OSHA's) process safety management (PSM) and does not meet Standard Industrial Classification (SIC) codes listed in the rule.  Therefore,  
the Mermentau Facility is classified as a Program 2 process under the ARP program. 
 
OFF-SITE CONSEQUENCE ANALYSIS RESULTS 
 
Flammable Substances - Worst-Case Scenario 
 
The endpoint for worst-case release of flammable substances is 1 psi overpressure (i.e., 15.7 psia), resulting from a vapor cloud explosion. The ARP Program requirement for flammables assumes an instantaneous release and vapor cloud explosion.  A yield factor of 10 percent of the available energy released in the explosion shall be used to determine the distance to the explosion endpoint.  Since the worst-case release scenario for a flammable substance is based on the assumption that the entire quantity of the substance forms a vapor cloud, passive mitigation systems are not applicable.  n-Butane is the worst-case flammable release with a 1.17-mile distance to the endpoint. 
 
Flammable Substances - Alternative-Case Scenario 
 
A single alternative release scenario for all flammable substances is required under the ARP program 
.  A hypothetical, but likely to occur, release scenario has been identified for n-butane as follows.  Seal failure on the n-butane product pump causes a release from a one-inch opening at 50 psig (suction pressure) and 700F.  The release is assumed to continue for ten minutes.  The n-butane will vaporize and may ignite in a vapor cloud explosion with an endpoint of 1 psi overpressure or a vapor cloud fire with an endpoint of the lower flammability limit (LFL) for n-butane.  The alternative-case release of n-butane resulted in a 0.07-mile distance to the 1 psi overpressure endpoint and less than 0.06 mile distance to the LFL endpoint.   
 
Toxic Substances 
 
The Mermentau Facility does not have any toxic substances held above the threshold quantity.  Therefore, analysis of worst-case or alternative case release scenarios for toxic substances is not required. 
 
 
GENERAL ACCIDENT RELEASE PROGRAM 
 
The following is a summary of the of the accident prevention program in place at the Mermentau F 
acility.  Because the Mermentau Facility is regulated by the Environmental Protection Agency's (EPA's) risk management program (RMP) regulation as a Program 2 process, it is also subject to a portion of the OSHA PSM standard prevention program elements.  This summary addresses each of the OSHA PSM elements and describes the management system in place to implement the accident prevention program. 
 
Safety Information 
 
The Mermentau Facility keeps a variety of technical documents that are used to help maintain safe operation of the processes.  These documents address chemical properties and associated hazards, limits for key process parameters and specific chemical inventories, and equipment design basis/configuration information. 
 
Chemical-specific information, including exposure hazards and emergency response/exposure treatment considerations, is provided in material safety data sheets (MSDS).  This information is supplemented by documents that specifically address known corrosion conce 
rns.  For specific process areas, the facility has documented safety related limits for specific process parameters (e.g., temperature level) in a Key Process Parameter Document.  The facility ensures that the process is maintained within these limits using process controls and monitoring instruments, highly trained personnel, and protective instrument systems (e.g., automated shutdown systems). 
 
The facility also maintains numerous technical documents that provide information about the design and construction of process equipment.  This information includes materials of construction, design pressure and temperature ratings, and electrical rating of equipment. This information, in combination with written procedures and trained personnel, provides a basis for establishing inspection and maintenance activities, as well as for evaluating proposed process and facility changes to ensure that safety features in the process are not compromised. 
 
Hazard Review 
 
The Mermentau Facility has a co 
mprehensive review program to help ensure that hazards associated with the regulated substances, processes and procedures are identified and controlled to prevent equipment malfunction or human error that could cause an accidental release.  The review program also identifies the steps used or needed to detect or monitor such releases.   
 
The Mermentau Facility uses hazard review techniques developed by persons knowledgeable about the process and equipment, to determine whether the process is designed, fabricated and operated in accordance with applicable standards or rules.  The reviews are conducted using a team of people who have operating and maintenance experience as well as engineering expertise.  The review team findings are documented and forwarded to local management and corporate engineering for resolution. 
 
To help ensure that the process controls and/or process hazards do not eventually deviate significantly from the original design safety features, the facility periodically 
updates and revalidates the hazard review results.  These periodic reviews are conducted at least every 5 years and will be conducted at this frequency until the process is no longer operating.  The facility also conducts reviews whenever a major change in the process occurs.  The findings of the review are resolved before startup of the changed process. 
 
Operating Procedures 
 
The Mermentau Facility maintains written procedures that address various modes of process operations, such as; (1) startup, (2) normal operations, (3) temporary operations, (4) emergency shutdown, (5) normal shutdown, and (6) initial startup of a new process.  These procedures provide guidance for experienced operators and also provide the basis for training new operators.  Operating procedures are periodically reviewed and annually certified as current and accurate.  The review and certification process involves both operators and technical staff. 
 
The intent of the operating procedures is to provide workable,  
useful, and clearly written instructions for conducting operating activities.  To have effective operating procedures, the task and procedures directly and indirectly related to the covered process must be appropriate, clear, consistent, and most importantly, communicated to employees.  Operating procedures are specific instructions or details on what steps are taken or followed in carrying out the stated procedures.  The specific instructions include the applicable safety precautions and appropriate information on safety implications. 
 
Training 
 
In addition to training on operating procedures the Mermentau Facility has a comprehensive training program for all employees involved in operating the process.  New employees receive basic training in facility operations.  In addition, all operators periodically receive refresher training on the operating procedures to ensure that their skills and knowledge are maintained at acceptable levels.  This refresher training is conducted at least ev 
ery 3 years.  All of this training is documented for each operator including the means used to verify that the operator understood the training. 
 
Maintenance 
 
The Mermentau Facility has well established practices and procedures for maintaining process equipment.  The basic aspects of this program include (1) training, (2) developing written procedures, (3) performing inspections and tests, (4) correcting equipment deficiencies, when identified, and (5) applying quality assurance measures.  In combination, these activities form a system that maintains the mechanical integrity of the process. 
 
Maintenance personnel receive training on (1) an overview of the process, (2) safety and health hazards, (3) applicable maintenance procedures, (4) emergency response plans, and (5) applicable safe work practices to help ensure that they can perform their jobs in a safe manner. 
 
Another integral part of maintenance program is quality assurance.  The Mermentau Facility incorporates quality assurance 
measures into equipment purchases and repairs.  This helps ensure that new equipment is suitable for its intended use and that proper materials and spare parts are used when repairs are made. 
 
The Mermentau Facility uses contractors during periods of increased maintenance or construction activities.  Because some contractors work on or near process equipment, the facility has procedures in place to ensure that contractors (1) perform their work in a safe manner, (2) have appropriate knowledge and skills, (3) are aware of the hazards of their workplace, (4) understand what they should do in the event of an emergency, (5) understand and follow site specific safety rules, and (6) inform facility personnel of any hazards that they find during their work.  This is accomplished by providing contractors with an orientation session that covers (1) a process overview, (2) information about safety and health hazards, (3) emergency response plan requirements, and (4) safe work practices prior to 
beginning their work.  In addition the Mermentau Facility evaluates contractor safety programs and performance during the selection of a contractor.  Facility personnel periodically monitor contract performance to ensure that contractors are fulfilling their safety obligations. 
 
Incident Investigation 
 
The Mermentau Facility promptly investigates all incidents that resulted in or reasonably could have resulted in, a fire/explosion, major property damage, environmental loss, or personal injury.  The goal of each investigation is to gather the facts, determine the root cause, and develop corrective action to prevent the reoccurrence of the incident or a similar incident.  The investigation team documents its findings, develops recommendation to prevent a recurrence, and forwards these results to the facility management for resolution. 
 
Compliance Audits 
 
To help ensure that the accident prevention program is functioning properly, the Mermentau Facility periodically conducts an audit to  
determine whether the procedures and practices required by the accident prevention program are being implemented.  Compliance audits are conducted at least every 3 years.  Both hourly and staff personnel participate as audit team members.  The audit team develops findings that are forwarded to facility management for resolution. Corrective actions taken in response to the audit team's findings are tracked until they are complete.  The final resolution of each finding is documented, and the two most recent audit reports are retained. 
 
CHEMICAL SPECIFIC PREVENTION STEPS 
 
The processes at the Mermentau Facility have hazards that must be managed to ensure continued safe operation.  The following is a description of existing safety features applicable to prevention of accidental releases of regulated substances in the facility. 
 
Universal Prevention Activities 
 
The accident prevention program summarized previously is applied to all RMP-covered processes at the Mermentau Facility.  Collectiv 
ely, these prevention program activities help prevent potential accident scenarios that could be caused by equipment failures and human errors. 
 
Specialized Safety Features 
 
The Mermentau Facility has safety features on many units to help (1) contain/control a release, (2) quickly detect a release, and (3) reduce the consequences of (mitigate) a release.  The following types of safety features are used in the covered processes. 
 
Release Detection 
 
1. Hydrocarbon detectors with alarms 
 
Release Containment/Control 
 
1. Valves to permit isolation of the process (manual or automated) 
2. Automated shutdown systems for specific process parameters (e.g., high  temperature) 
3. Curbing or diking to contain liquid releases 
4. Redundant equipment and instrumentation (e.g., uninterruptible power supply for process control system, backup firewater pump) 
5. Atmospheric relief devices 
 
Release Mitigation 
 
1. Fire suppression and extinguishing systems  
2. Deluge system for specific equipment 
3. Traine 
d personnel in emergency procedures 
4. Personal protective equipment (e.g., chemical protective clothing, face shields) 
 
FIVE YEAR ACCIDENT HISTORY 
 
The Mermentau Facility has an excellent record of accident prevention.  Over the past 5 years there have been no accidental releases. 
 
EMERGENCY RESPONSE PROGRAM INFORMATION 
 
The Mermentau Facility maintains a written emergency response program, which is in place to protect worker and public safety as well as the environment.  The program consists of procedures for responding to a release of a regulated substance, including the possibility of a fire or explosion if a flammable substance is accidentally released.  The procedures address all aspects of emergency response, including proper first aid and medical treatment for exposures, evacuation plans and accounting for personnel after an evacuation, notification of local emergency response agencies and the public if a release occurs, and post-incident cleanup and decontamination requirement 
s.  In addition, the facility has procedures that address maintenance, inspection, and testing of emergency response equipment, as well as instructions that address the use of emergency response equipment.  Employees receive training in these procedures as necessary to perform their specific emergency response duties.  The emergency response program is updated when necessary based on modifications made to the Mermentau Facility. The emergency response program changes are administered through the Management of Change process, which includes informing and/or training affected personnel in the changes. 
 
The overall emergency response program for the Mermentau Facility is coordinated with the Jefferson Davis Parish, Louisiana, Local Emergency Planning Committee (LEPC).  This coordination includes periodic meetings of the committee, which includes local emergency response officials, local government officials, and industry representatives.  The Mermentau Facility has around-the-clock commun 
ications capability with appropriate LEPC officials and emergency response organizations (e.g., fire department). This provides a means of notifying the public of an incident, if necessary, as well as facilitating quick response to an incident.  In addition to periodic LEPC meetings, the Mermentau Facility conducts periodic emergency drills that involve the LEPC and emergency response organizations, and the facility provides annual refresher training to local emergency responders regarding the hazards of regulated substances in the plant.
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