HPL Resources Company McMullen Gas Plant - Executive Summary |
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HPL Resources Company McMullen Gas Plant's Commitment to Safety Accident Prevention and Emergency Response Policies The McMullen Gas Plant is committed to safe, clean and efficient handling and storage of flammable mixtures meeting NFPA 4 criteria. The resources invested in accident prevention, such as training personnel and considering safety in the design, installation and operation of our process containing flammable mixtures demonstrate this commitment. Facility Description and Substance Handled The McMullen Gas Plant is located at 99 South FM Road, Tilden, TX 78072. The McMullen Gas Plant operates one Program Level 3 process. This process receives, handles, and stores a regulated flammable mixture. The gas plant receives natural gas via pipelines, separates out liquids, and discharges the natural gas back into the transmission pipelines. The liquids are stored onsite until loaded onto tank trucks and transported offsite. The McMullen Gas Plant does not use any regulated to xic chemicals. Worst-Case and Alternative Release Scenarios A worst-case scenario is defined as the catastrophic release of the largest inventory of the regulated substance from a single vessel. For regulated flammable mixtures that are normally liquids at ambient temperature, the release is an instantaneous release of the entire inventory, which forms a liquid pool. For liquids at temperatures below their atmospheric boiling point, the volatilization rate shall be calculated at the following conditions: 7 Highest daily maximum temperature occurring in the past three years, 7 The temperature of the substance in the vessel 7 The concentration of the substance if the liquid spilled is a mixture or solution. Assume that the quantity, which becomes vapor in the first ten (10) minutes, is reported as the quantity released. The worst-case scenario assumes that none of the many process controls and safety systems are operational. The process controls and safety systems at the McMullen Gas Plant include mechanical integrity of the natural gas process system, detectors, alarms, etc. The alternative release scenario is a scenario, which is more likely to occur than the worst case release scenario, and which will reach an endpoint offsite. One worst-case scenario and one alternative release scenario are presented in this RMP. The distance for the worst-case release scenario was calculated using the Baker-Strehlow method. The distance for the alternative release scenario was determined using the look-up tables in the EPA Guidance Document. The worst-case release is a release of the entire contents of Stabilized Product Storage Tank (43,000 lbs.). The distance to the 1 psi endpoint is 570 feet. This release scenario does have an offsite impact. One small office building is impacted. No other public receptors are impacted. No environmental receptors are impacted. The more realistic alternative flammable release scenario is a complete seal failure on the Gasolin e Loading Pump located outside the Stabilized Product Storage Tank dike. The release is assumed to continue for 1 minute. Approximately 135 lbs. of stabilized product are released. The release goes offsite. The distance to the 1-psi endpoint is 149 ft. This release scenario impacts no members of the public, no public receptors, and no environmental receptors. General Accidental Release Prevention Program - Specific Steps The McMullen Gas Plant has a comprehensive accidental release prevention program. The program addresses the flammable hydrocarbon handling that is covered by the EPA's RMP rule and OSHA's Process Safety Management regulation. The accidental release prevention program involves process design, equipment design, and construction to meet all applicable codes and standards. In addition, a number of safety systems, such as process controls, warning alarms, and operational controls are in place to prevent a release from occurring. The McMullen Gas Plant has written safety information on the flammable hydrocarbon process, equipment and procedures. This information is available to all employees who work in the gas plant. This documentation includes information on the hazards of flammable hydrocarbons, the technology of the process, and the equipment in the process. The overall effectiveness of the accidental release prevention program has been monitored by Process Hazards Analyses (PHAs), which have been performed for the flammable hydrocarbon process. PHAs provide a method for understanding potential hazardous events, the means by which they occur and what actions are likely to prevent them from occurring. A team approach is used on the PHAs to evaluate the potential consequences of failures in the flammable hydrocarbon process. The safeguards in place for each hazard are recorded and evaluated on a case-by-case basis. Recommendations are then made to improve safety where the existing safeguards were not considered adequate by the PHA team . A PHA of the flammable hydrocarbon process was completed in 1994 and will be updated on a 5-year cycle. The basis for proper and safe operation of the flammable hydrocarbon system is provided by written operating procedures. These procedures define the operating limits, identify safety and health considerations, and detail the operation and function of safety systems. Specific modes of operation covered are startup, normal operations, emergency and normal shutdown, and temporary operations. To complement the written operating procedures, the McMullen Gas Plant employees receive training in specific safety and health hazards, operation of the flammable hydrocarbon process, emergency operations and all applicable safe work practices for the system. The McMullen Gas Plant has a mechanical integrity program to ensure that all equipment is regularly inspected and maintained. All inspections and maintenance operations are documented. The McMullen Gas Plant has quality assurance mea sures to ensure that new equipment is suitable for its intended use and that the proper material and spare parts are used when repairs are made. The McMullen Gas Plant has a comprehensive system to manage changes. The management of change (MOC) procedures ensure that any changes which are not "replacement-in-kind" are documented and analyzed to ensure that the change is safe. The MOC procedure ensures that all changes are documented and properly authorized. The procedures also ensures that all employees whose job tasks will be affected by the change are informed and receive appropriate training prior to the change. A pre-startup safety review will be conducted for any new covered process or significant modification to the flammable hydrocarbon process. The purpose of these reviews is to ensure that safety features, procedures, personnel, and equipment are appropriately prepared prior to operation. The performance of these safety programs and procedures is monitored through audit s, periodic drills and inspections. The McMullen Gas Plant will investigate any incident that results in, or could result in, a release of regulated flammable mixtures. These investigations will follow a written procedure and be performed by a team from HPL Resources Company. The goal of incident investigation is to determine the root cause of the accident and to develop corrective actions to prevent reoccurrence of the incident. All corrective actions taken in response to the investigation team recommendations will be tracked until complete. The employee participation plan details employee involvement in safety and the prevention program. The McMullen Gas Plant has a contractor safety program to ensure that contractors who work in or adjacent to the flammable hydrocarbon process are properly trained and meet safety criteria defined by HPL Resources Company. Five Year Accident History The McMullen Gas Plant has experienced one accidental release in the last five years, which meet s the EPA reporting requriements. The release was approximately five pounds of flammable material and caused a flash fire. No offsite public or environmental receptors were impacted; however, one employee was injured onsite. Emergency Response Program To be prepared for potential fires, the McMullen Gas Plant communicates with the Tilden Volunteer Fire Department who is contacted by the gas plant in the event of a NFPA 4 flammable liquid release. The McMullen Gas Plant has an Emergency Response Plan and employees have received emergency response training. Safety Improvements To achieve the McMullen Gas Plant's excellent safety track record, safety improvements have been made over the last decade. These include: - Reduction in propane - Reduction in butane - Elimination of depropanizer - Elimination of debutanizer The McMullen Gas Plant will continue to monitor the effectiveness of the prevention programs and provide continuous improvement. |