Exxon Company, U.S.A. Big Escambia Creek Gas Plant - Executive Summary |
|
Accidental Release Prevention and Response Policies Exxon modified its safety programs in 1992 by implementing structured safety management systems entitled Operations Integrity Management System (OIMS). In 1997, Lloyd's Register Quality Assurance reviewed OIMS and evaluated it against the international standard for Environmental Management Systems (ISO 14001) to determine if OIMS meets the requirements of ISO 14001. After an extensive review which included a number of facility audits, they concluded that the "environmental components of OIMS are consistent with the intent and meet the requirements of the ISO 14001 Environmental Management Systems Standard." They went on to say, "We further believe Exxon to be among the industry leaders in the extent to which environmental management considerations have been integrated into its ongoing business processes." The Exxon Company, U.S.A. Big Escambia Creek Gas Plant has a long-standing commitment to worker and public safety. This commi tment is demonstrated by the resources invested in accident prevention (e.g., training of personnel, considering safety in the design, installation, operation, and maintenance of the facility, etc.). Our approach is to implement reasonable controls to prevent foreseeable releases of regulated substances as well as other substances. If a release does occur, our trained personnel will take steps to control and contain it until local emergency response organizations arrive. Additional details are included in the other sections of this RMPlan. Description of the Stationary Source and Regulated Substances The Exxon Company, U.S.A. Big Escambia Creek Gas Plant, located 4.5 miles West of Flomaton, Alabama, and 3.3 miles north on state road 2, consists of one Program Level 3 process which utilizes several operations (e.g., separation, dehydration, compression, cryogenic) to produce petroleum products (e.g., natural gas liquid mixture, methane) from a naturally occurring hydrocarbon gas mixture. The Plant could contain up to 6,500,000 pounds of regulated flammables (e.g., mixtures containing methane, ethane, propane, butane, iso-butane, pentane, and iso-pentane), and 43,000 pounds of Hydrogen Sulfide, a toxic gas. All transportation of regulated flammables into and out of the facility is handled via pipelines and by some truck transport. The Plant is surrounded by a combination of farmland, forest, residences and a few other businesses. The Title V permit for this facility has been submitted and approval is pending. Offsite Consequence Analysis Results Worst Case Scenario (WCS)-Toxic The WCS as associated with toxic substances, as defined in the regulation, is a release of hydrogen sulfide gas involving the maximum inventory of the largest vessel. This scenario is extremely remote, but is required by the EPA regulation. Even though the normal operating pressure and inventory for this equipment is less than the maximum capacity and this equipment is protect ed by high level alarms/shutdowns, pressure relief valves, periodic inspections, and routine monitoring by operating personnel, this maximum inventory must be assumed to be released. No mitigation measures were taken into account in evaluating this WCS. The WCS potentially has off-site impacts, but there are no environmental receptors. Alternate Release Scenario (ARS)-Toxic The ARS is a release of H2S gas venting to the low-pressure flare. Even though this event is unlikely (i.e., process is protected by alarms, routine monitoring by operating personnel, and periodic inspections), the toxic substance was assumed to be released without ignition at the flare tip. No passive mitigation measures were taken into account in evaluating this ARS. The ARS has off-site impact potential, but the impact area includes few public receptors and no environmental receptors. Worst Case Scenario (WCS)-Flammable The WCS, as defined in the regulation, is a release of flammable materials (i.e., mi xture of natural gas liquids) resulting in a vapor cloud explosion (VCE) involving the maximum inventory of the largest vessel. This scenario is extremely remote, but is required by the EPA regulation. Even though the normal operating inventory for this equipment is significantly less than the maximum capacity and this equipment is protected by high level alarms/shutdowns, pressure relief valves, periodic inspections, and routine monitoring by operating personnel, this maximum inventory must be assumed to be released in 10 minutes and ignited at the point of release. No mitigation measures were taken into account in evaluating this WCS. The WCS has off-site impact potential, but the impact area includes few public receptors and no environmental receptors. Alternate Release Scenario (ARS)-Flammable The ARS is a release of flammable materials (i.e., mixture of natural gas liquids) failure by a pressure relief valve to reseat resulting in a vapor cloud explosion (VCE). Even though this event is unlikely (i.e., process is protected by high level alarms/shutdowns, periodic inspections, and routine monitoring by operating personnel), the maximum inventory of flammable materials in this vessel was assumed to be released and ignited at the point of release. No passive mitigation measures were taken into account in evaluating this ARS. The ARS could have off-site impact potential, but the impact area does not include any public or environmental receptors. General Accidental Release Prevention Program The following is a summary of the accident prevention program in place at the Plant. Because processes at the Plant regulated by EPA's Risk Management Program (RMP) regulation are also subject to (and in compliance with) OSHA's Process Safety Management (PSM) standard, this summary addresses each of the OSHA PSM elements and describes the management system in place to implement the accident prevention program. Employee Participation The Plant provides for and encou rages employees to participate in all aspects of process safety management and accident prevention. Examples of employee participation range from updating/compiling technical information and drawings to participating on process hazard analysis (PHA) or incident investigation teams. Employees have access to all information related to the accident prevention program. Specific ways that employees can be involved in the accident prevention program are detailed in an Employee Participation Plan that is maintained at the Plant and addresses each program element. In addition, the Plant has other initiatives that address process and employee safety issues (e.g., hazard reporting/resolution process and numerous safety meetings [daily, monthly, pre-job], etc.). Process Safety Information (PSI) The Plant keeps a variety of technical documents that are used to help maintain safe operation of the facility. These documents address chemical properties and associated hazards, safe operating limi ts for key process parameters, specific chemical inventories, and equipment design basis/configuration information. OIMS Coordinator at the Plant is responsible for coordinating the PSI updates. Chemical-specific information (including exposure hazards, emergency response, and exposure treatment considerations) is provided in material safety data sheets. For specific process areas, the Plant has documented safety-related operating limits for process parameters (e.g., temperature, pressure, level) in the operating procedures. The Plant ensures processes are maintained within these limits using process controls/monitoring equipment, highly trained personnel, and protective instrument systems (e.g., automated shutdown systems, pressure relief valves). The Plant also maintains numerous technical documents that provide information about the design and construction of the process equipment. This information includes the materials of construction, design pressure, temperature ratings, a nd electrical rating of equipment. This information, in combination with written procedures and trained personnel, provides a basis for inspection/maintenance activities and the evaluation of proposed process or facility changes. Process Hazard Analysis (PHA) The Plant has a comprehensive program to help ensure hazards associated with the various processes are identified and controlled. Within this program, each process is systematically examined to identify hazards and ensure adequate controls are in place to manage these hazards. The Plant primarily uses the What If/Checklist analysis technique to perform these evaluations. This technique is recognized by OSHA as an acceptable hazard evaluation technique for PSM-covered processes. The analyses are conducted using a team of Plant operating/maintenance personnel and facility engineers, and technical consultants (as necessary). This team identifies and evaluates hazards of the processes as well as the accident prevention and miti gation measures. The PHA team findings are forwarded to management to coordinate further evaluation and resolution. This process involves field level business teams, which include engineering, operations personnel, and management. Operating personnel are also involved in the evaluation of resolution options. Implementation of the resolutions is based on relative risk. Potential accident scenarios assigned the highest risk are addressed first. All resolution plans are tracked until completed. The final resolution of each finding is documented and retained. To help ensure the process controls and/or hazards do not eventually deviate significantly from the original design; the Plant updates and revalidates the process hazard analysis at least every 5 years. The results of these updates are also documented and retained. Similarly, the team's findings are forwarded to management to coordinate further evaluation and resolution, and the final resolution of findings are documented and retained. Operating Procedures The Plant maintains written procedures that address the various modes of process operations (e.g., startup, normal, temporary, emergency shutdown, normal shutdown, cold startup) and provide guidance on how to respond to upper/lower limit exceedances for specific equipment or process parameters. Procedures are readily available to operators and other personnel to use as necessary to safely perform their job tasks. These procedures provide a consistent basis for training new operators and are annually reviewed and certified as current/accurate. Procedures are maintained current/accurate by revising them as necessary to reflect changes made through the management of change process. Training To complement the written operating procedures, the Plant has implemented a comprehensive training program for all employees involved in operating process equipment. New employees receive basic training in Plant operations (e.g., process overview, applicable pro cedure reviews, etc.). New operators are then paired with experienced operators (i.e., subject matter experts) to learn process-specific duties and tasks. After the new operators demonstrate that they have adequate knowledge to perform the duties and tasks in a safe manner on their own, they are certified and allowed to work independently. In addition, all personnel who operate process equipment receive refresher training at least every 3 years on the applicable procedures to help ensure their skills and knowledge are maintained at an acceptable level. This training and the means used to verify that the employee understood the training is documented for each employee. Contractors The Plant uses contractors to supplement its workforce during periods of increased maintenance or construction activity. Because some contractors work on or near process equipment, the Plant has procedures in place to help ensure contractors (1) perform their work in a safe manner, (2) have the appropria te knowledge and skills, (3) are aware of the hazards in the workplace, (4) understand what they should do in the event of an emergency, (5) understand and follow safety rules, and (6) inform Plant personnel of any hazards they find during their work. This is accomplished by providing contractors an orientation prior to their working in the Plant which includes (1) process overview, (2) information about safety and health hazards, (3) applicable emergency action plan provisions, and (4) information on safe work practices. Also, a job safety analysis is reviewed/updated or developed by the contractors (with Plant personnel assistance as needed) prior to each maintenance/construction task. Plant personnel routinely monitor contractor job performance to help ensure they are fulfilling their safety obligations. Contractor safety programs/performance are evaluated during the initial selection process, and the Plant supervisor conducts periodic evaluations of safety performance. Pre-Sta rtup Safety Reviews (PSSR) The Plant conducts a PSSR for any Plant modification that requires a change in the process safety information. The purpose of the PSSR is to ensure safety features; procedures, personnel, and equipment are appropriately prepared for startup prior to placing the equipment into service. This review provides one additional check to make sure that construction is in accordance with the design specifications and all supporting systems are operationally ready. A PSSR involves field verification of the construction and serves a quality function by verifying that the requirements of this accident prevention program are properly implemented. Mechanical Integrity (MI) The Plant has well-established practices and procedures to maintain pressure vessels, piping systems, relief/vent systems, controls, pumps, compressors, and emergency shutdown systems in a safe operating condition. The basic aspects of this MI program include (1) training, (2) written procedures, (3) inspections/tests, (4) correction of identified deficiencies, and (5) quality assurance measures. In combination, these activities form a system that maintains the mechanical integrity of the process. Maintenance personnel receive training on the (1) process, (2) safety and health hazards, (3) applicable maintenance procedures, (4) emergency procedures, and (5) applicable safe work practices to help ensure they perform their jobs in a safe manner. Written procedures and equipment manuals help ensure work is performed in a consistent manner and provide a basis for training. Inspections/tests and preventive maintenance are performed on a scheduled basis to help ensure equipment and safety devices function as intended and to verify that equipment is within acceptable limits (e.g., adequate wall thickness, etc.). If a deficiency is identified, employees correct the deficiency before placing the equipment back into service or a group of experts (e.g., engineers, etc.) review the use of the equipment and determine what actions are necessary to ensure safe operation of the equipment until the deficiency can be corrected. Another integral part of the MI program is quality assurance. The Plant incorporates quality assurance measures into equipment purchases and repairs to help ensure new equipment is suitable for its intended use and proper materials/spare parts are used for repairs. Hot Work and Other Safe Work Practices The Plant has long-standing safe work practices in place to help ensure worker and process safety. These include orientations for visitors/contractors, control of the entry/presence/exit of support personnel, energy isolation for equipment being worked on, procedures for the safe removal of hazardous materials before opening of process piping/equipment, hot work permit/procedure to safely manage spark-producing activities, vehicle entry into process area, confined space entry permit/procedure to help ensure precautions are taken before entering confined spaces, job safety analyses to identify and mitigate hazards associated with maintenance tasks). These practices, along with related procedures and training of affected personnel, form a system to help ensure operations and maintenance activities are performed safely. Management of Change (MOC) The Plant has a comprehensive system to manage changes. This system requires that changes to process equipment, chemicals, technology (including process operating conditions), procedures, and other facility changes be properly reviewed and authorized before being implemented. Changes are reviewed to ensure adequate controls are in place to manage any new hazards and verify that existing controls have not been compromised by the change. Affected chemical hazard information, process operating limits, equipment information, drawings, and procedures are updated for these changes. In addition, operating and maintenance personnel are provided any necessary training related to the change . Incident Investigation The Plant promptly investigates all incidents that resulted in (or could have reasonably resulted in) a fire, explosion, release, major equipment/property damage, environmental loss, or personal injury. The goal of each investigation is to determine the facts and develop corrective actions to prevent recurrence of the incident or a similar incident. The investigation team documents its findings, develops recommendations, and forwards these results to management for resolution. Corrective actions taken in response to the investigation team's findings are tracked until completed. The final resolution of each finding is documented, and investigation results are reviewed with all employees (including contractors) who could be affected. Incident investigation reports are retained for at least 5 years so that reports can be reviewed during the next PHA revalidation. Compliance Audits To help ensure the accident prevention program is functioning properly, an au dit is conducted at the Plant at least once every 3 years to determine whether the program's procedures and practices are being implemented. An audit team consisting of both Plant and technical personnel evaluate the implementation/effectiveness of the processes in this accident prevention program and develop findings that are documented and forwarded to management to coordinate resolution. Corrective actions are taken in response to the audit team's findings, and resolution status is tracked until actions are completed. 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 Plant have hazards that are managed to help ensure continued safe operation. The following is a description of existing safety features applicable to the prevention of accidental releases of the specific regulated substances (i.e., flammables) in the Plant. Universal Prevention Activities The accident prev ention program summarized previously is applied to the RMP-covered process at the Plant. These prevention program activities help prevent potential accident scenarios that could be caused by equipment failures and human errors. Specialized Features The Plant has safety features on many units to (1) quickly detect a release, (2) contain/control a release, and (3) reduce/mitigate the consequences of a release. The following types of safety features are used: Release Detection .... * hydrocarbon gas detectors/alarms near gas turbines * hydrocarbon gas detectors/alarms near product shipping pumps * hydrogen sulfide gas detectors/alarms in the process area Release Containment/Control .... * pressure/thermal relief valves and rupture disks that discharge into a flare system for incineration * manual/automatic isolation valves * automated shutdown systems for specific process parameter (e.g., pressure, high level, etc.) * redundant equipment and instrumentation (e.g., dual relief va lves, backup firewater pump, etc.) Release Mitigation .... * fire extinguishing systems (e.g., fire monitors/hoses, portable fire extinguishers, lite water) * personal protective equipment (e.g., self-contained breathing apparatus) Five Year Accident History The Plant has had a very good record for accident prevention over the past 5 years. While there has not been an incident with offsite impacts, there has been one release as defined in the regulation that is reportable due to the amount of damage sustained to onsite equipment. The incident did not result in any personal injury or environmental damage. Additional detail is included in Section 6 of this RMPlan. Emergency Response Program Information The Plant maintains an emergency action program to protect the workers, public, and environment. The program consists of procedures for handling releases of regulated flammable and toxic substances including the possibility of fires or explosions. The procedures address facili ty/equipment isolation and shutdown, initial first aid and medical treatment for exposures (i.e. Material Safety Data Sheets information), evacuation plans for the Plant, accounting for Plant personnel after an evacuation, notification of local emergency response agencies, and post-incident cleanup/decontamination requirements. In addition, the Plant has procedures that address the maintenance, inspection, and testing of emergency equipment and alarms. Plant personnel receive training in these procedures as necessary to perform their specific duties. The emergency action program is reviewed annually and updated when necessary. Plan changes required because of modifications to the Plant facilities or emergency equipment are administered through the management of change process, which includes informing and/or training affected personnel. The overall emergency response program for the Plant is coordinated with the Escambia County Emergency Management Association (LEPC), the Atmore , Alabama, Fire Department, Escambia County Sheriff's Department, and the local ambulance service. The Plant has around-the-clock communications capability with these emergency response organizations. These organizations are responsible (if necessary) for notifying the public, coordinating the community response (e.g., blocking off roads, evacuation, etc.), and providing the onsite response (e.g., fire fighting, medical treatment, etc.). The Plant conducts periodic emergency action drills and provides periodic refreshers to the local emergency response organizations on the hazards associated with the Plant operations. The Plant also supports an automated "Community Alert Network" emergency alert system that phones residents within certain pre-defined areas and provides a phone message in the advent of an emergency. The Plant operators can activate this system from the Plant control room. Recent Changes to Improve Safety Our Operations Integrity Management Systems form the corner stone for continuous improvement in our safety-related systems. These systems are evergreen and are in a continuous state of improvement, usually through many small improvement steps. These improvement steps are tightly integrated with our training programs. The Plant resolves all findings from PHAs, incident investigations, and safety audits. The following are some of the changes that are currently being implemented (or were recently completed) to improve the safety of this operation: 1. Modified discharge piping to prevent process freezing 2. Upgraded control room pressurization system 3. Upgraded equipment failure analysis process via incorporation of structured "Root Cause" analysis and additional system training. |