Bridgeport Gas Plant - Executive Summary |
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BRIDGEPORT RISK MANAGEMENT PLAN EXECUTIVE SUMMARY The Bridgeport gas plant 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 our processes. Our policy is to implement reasonable controls to prevent foreseeable releases of regulated substances. However, if a release does occur, trained personnel will respond to control and contain the release. The Bridgeport gas plant, located 3< miles west of Bridgeport, Texas, operates a variety of processes to produce pipeline quality natural gas and natural gas liquids (such as ethane, propane and butane). The processes used include glycol dehydration, amine sweetening to remove CO2, propane refrigeration, fractionation, cryogenic processing and related utilities. Some of the chemicals produced or used include methane, ethane, propane , butane, triethylene glycol and diethanolamine. OFFSITE CONSEQUENCE ANALYSIS RESULTS No H2S is stored, used or processed at the facility. There are no toxic chemicals stored at the Bridgeport gas plant above the EPA Threshold Quantity. The threshold quantity is the level set by EPA for each toxic or flammable chemical which if stored at the site requires compliance with the EPA's Risk Management Program regulations. Generally, if the amount of a substance stored on-site is less than the threshold quantity, there is little danger to the public. There are several flammable substances stored at the site above the 10,000 pound threshold quantity for flammables. Examples of flammables at the site include methane, ethane, propane and butane. The worst-case scenario associated with a release of flammable materials is a vapor cloud explosion (VCE) involving the full inventory of the 75,000 gallon storage tank containing propane. Based on EPA analysis, the distance away from t he plant affected in this worst-case scenario would be approximately 0.55 miles. A more probable release scenario would involve the release of propane from a transfer line during loading operations. Based on loading a truck in one hour, we would release approximately 1500 gallons in 10 minutes, at which time our operators would detect and isolate the line or gas detection would shut down the plant. The affected distance based on EPA guidance is approximately 0.15 miles, or approximately 790 feet. GENERAL ACCIDENT RELEASE PREVENTION PROGRAM The Bridgeport gas plant has a very active accident prevention program in place, primarily based on the OSHA Process Safety Management regulations. A summary of some of the accident prevention programs that are in place follows. Process Safety Information The Bridgeport gas plant keeps a variety of technical documents that are used to help maintain safe operation of the processes. These documents include material safety data sheets for all chemicals on-site, up-to-date process and instrumentation drawings, equipment data sheets on all vessels and equipment and process parameter safety limits. 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. Process Hazard Analysis (PHA) The Bridgeport gas plant has a very comprehensive program to ensure that hazards associated with the various processes are identified and controlled. Each process is systematically examined to identify hazards and ensure that adequate controls are in place to manage these hazards. The HAZOP analysis technique and the what-if/checklist methods are used to perform these evaluations. The analyses are conducted using a team of people with operating, maintenance, engineering and safety experience. T his team identifies and evaluates hazards of the process, as well as accident prevention and mitigation measures, and makes suggestions for additional prevention and/or mitigation measures when the team believes such measures are necessary.. All approved recommendations from the PHA team findings are tracked until they are completed. To help ensure that the process controls and/or process hazards do not eventually deviate significantly from the original design and to ensure that new technology is used where appropriate, the Bridgeport gas plant periodically updates and revalidates the hazard analysis results. These periodic reviews will be conducted at least every 5 years. Operating Procedures The Bridgeport gas plant maintains written procedures that address various modes of process operations. These procedures are used as reference by experienced operators, and provide a basis for consistent training of new operators. These procedures are periodically reviewed and c ertified as current and accurate. Training Our employees at the Bridgeport plant have an average experience of 18-20 years. This level of experience provides a great level of expertise throughout the facility at all times of the day. Ongoing training is accomplished through routine safety meetings, scheduled training in new processes and refresher training on operating procedures. Contractors The Bridgeport gas plant uses contractors to supplement its workforce during periods of increased maintenance or to assist with specialized projects. Contractors are advised about safety and health hazards, emergency response requirements and safe work practices prior to their beginning work. Gas plant personnel routinely monitor contractor performance to ensure that contractors are fulfilling their safety obligations. Mechanical Integrity The Bridgeport gas plant has well-established practices and procedures to maintain our equipment in a safe operating condition. The basic aspects of this program include inspections, tests and corrections of identified deficiencies. Inspections and tests are performed to help ensure that equipment functions as intended, and to verify that equipment is within acceptable limits. If a deficiency is identified, employees will correct the deficiency before placing the equipment back in service or they will determine what actions are necessary to ensure safe operation of the equipment. Safe Work Practices The Bridgeport gas plant has long-standing safe work practices to help ensure worker and process safety. Examples of these include lockout/tagout to ensure isolation of energy sources for equipment that is being worked on, a permit and procedure for hot work and a permit and procedure for confined space entry. These procedures (and others), along with training of affected personnel, form a system to help ensure that operations and maintenance activities are performed safely. Changes to our safe work p ractices implemented due to recent threats to the facility include controlled entry/exit into the facility, extra security around the facility, and improved identification of employees and contractors. Management of Change The Bridgeport gas plant has a comprehensive system to manage changes to all covered processes. This system requires changes to items such as process equipment, chemicals, technology (including operating conditions), procedures and other facility changes be properly reviewed and authorized before being implemented. Changes are reviewed to ensure that adequate controls are in place to manage any new hazards and to verify that existing controls have not been compromised by the change. Operating and maintenance personnel are provided any necessary training on the change. Incident Investigation The Bridgeport gas plant promptly investigates all incidents that resulted in, or reasonably could have resulted in, a fire/explosion, toxic gas release, majo r property damage, environmental loss or personal injury. The goal of each investigation is to determine the facts and develop corrective actions to prevent a recurrence of the incident or a similar incident. CHEMICAL-SPECIFIC PREVENTION STEPS The processes at the Bridgeport gas plant 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 specific regulated substances in the facility. The Bridgeport gas plant has safety features on many units to help (1) contain/control a release, (2) quickly detect a release, and (3) reduce the consequences of a release. The following types of safety features are used in the covered process Release Detection 1. Hydrocarbon detection sensors around critical areas. Release Containment/Control 1. Process relief valves that discharge to a flare to capture and incinerate episodic releases. 2. Valves (both manual and automatic) to permit isolation of the process. 3. Automated shutdown systems for specific process parameters (such as high pressure or high level in a vessel). 4. Curbing or diking to contain liquid releases. 5. Atmospheric relief devices. Release Mitigation 1. Fire suppression and extinguishing systems. We have two main types of fire suppression - monitors with water spray nozzles to cool equipment in case of fire and numerous fire extinguishers of several sizes throughout the facility. In gas plants, the control of fire is more dependent on restricting sources of fuel than on putting out the fire. 2. Spill response team. The Bridgeport plant has quick access to spill containment material. We have a team of employees who are trained and qualified to clean up spills from our facility in the unlikely event that they occur. ACCIDENT HISTORY The Bridgeport plant has not had an incident over the past five years which has impacted off-site people or structures. EMERGENCY RESPONSE PROGRAM INFORMATION The Bridgeport gas plant maintains a written emergency response program, which is in place to protect worker and public safety. The program consists of procedures for responding to a release, 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. In addition, the Bridgeport gas plant 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. Th e emergency response program is updated when necessary, based on modifications made to gas plant processes or other plant facilities The overall emergency response program for the Bridgeport gas plant is coordinated with the local emergency response organizations and the emergency planning committee. This coordination provides a means to notify the public in case of an incident, if necessary, as well as facilitating quick response to an incident. The Bridgeport facility recently had a simulated emergency drill, with participation from the local emergency planning coordinator of the county and numerous local response agencies. Not only did we learn more about their capability, but they became more familiar with our operations and how to respond in case of an incident. CONCLUSION The Bridgeport gas plant has had very safe operations over its history. However, the facility continually looks for improvements, both to the process and to safety issues at the facility. The f ollowing changes are planned over the next few years in response to PHA, safety audit and the simulated emergency drill findings: Upgraded control system to use distributed computerized control system Upgraded fire protection system throughout the facility Improved control room building Upgraded emergency shutdown system for the facility |