Sligo Central Facility
Haughton, LA 71110
Fort Worth, TX 76102 -6298
Person responsible for RMP implementation:
Latest RMP Submission:
2. Toxics: Worst-case
3. Toxics: Alternative release
4. Flammables: Worst-case
Some Risk Management Plan information is not provided in the available RMP data. You need to make an appointment at an EPA Reading Room In order to get access to details from the Off-Site Consequence Analysis (OCA) such as:
- Names of the chemicals in the Off-Site Consequence Analysis
- Amount of chemical released
- Rate of chemical release
- Radius of affected area
- Vulnerable areas affected
- Count of affected population
- Maps or other optionally provided supplementary material
Instructions on how to make an EPA appointment can be found here.
- Blast walls
5. Flammables: Alternative release
6. Five-year accident history
7. Prevention: Program level 3
8. Prevention Program level 2
9. Emergency response
ACCIDENTAL RELEASE PREVENTION AND RESPONSE POLICIES
The Sligo Plant places a strong commitment on worker safety. XTO Energy demonstrates this commitment by investing our resources in accident prevention, by continuous safety training, and by placing a high value on safety during design, installation, operation, and maintenance of our processes. Our goal is to implement reasonable goals to prevent foreseeable releases of regulated substances. In the event of a release, trained company personnel will respond accordingly to control and contain the release.
PRCESS DESCRIPTION OF THE FACILITY AND REGULATED SUBSTANCES
The Sligo Plant, located near Haughton, LA, operates a variety of processes to produce petroleum products (natural gas, propane, butane, and condensate) from natural gas. Regulated flammables such as propane and butane are present but no regulated toxic substances are present at Sligo. The facility is a refrigeration unit using compressed propane to cool the incoming gas stream. This liberates natural gas liquids which are separated in the three phase separator then stabilized in a tower using the glycol still as a heat source. The stabilized liquids are stored and trucked to delivery. The glycol is also used to inhibit freezing by injecting it into the inlet stream. The glycol is recovered in the three-phase separator and sent to the still to regenerate. The gas off the three phase separator is cross exchanged with the inlet then sent to sales.
OFFSITE CONSEQUENCE ANALYSIS RESULTS
The Worst Case Scenario (WCS) associated with a release of flammable substances in Program Level 2 processes at the Whelan Plant is a Vapor Cloud Explosion (VCE) involving the inventory of the largest storage tank containing 30,000 gallons (126,900 lbs.). The maximum distance to the 1-psi endpoint for this WCS is 0.40 miles. Although numerous controls are in place to prevent such releases and to manage their consequences, no credit
for passive mitigation measures was taken into account evaluating this WCS.
The Alternative Release Scenario (ARS) for flammable substances is a BLEVE. The maximum distance to the 1-psi endpoint for this event is also 0.40 miles. This event was selected as being a practical scenario for use in emergency planning and response.
GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM
The following is a summary of the accident prevention program in place at the Sligo Plant. It is a small, unmanned skid-mounted natural gas refrigeration plant. The plant is subject to EPA's risk management program (RMP) Program 1. The plant has more than a threshold quantity of flammable chemicals, e.g. natural gas and NGLs, in a process. The Sligo Plant is an entirely new facility. No of receptors are present within the distance to the worst-case release endpoint.
Process Safety Information
The Sligo Plant uses a wide range of reference materials to maintain safe operation of each process. These documents address specific chemical properties and associated hazards, limits for key process parameters and specific chemical inventories, and equipment design basis/configuration information.
The Sligo Plant has a comprehensive program to help ensure that hazards associated with the various processes are identified and controlled. Within the program, each process is analyzed to identify potential hazards and ensure that adequate controls are in place to manage these hazards.
The hazard analysis is conducted by a company engineer with maintenance experience as well as engineering expertise of this type of facility. He analyzes and evaluates hazards of the processes, as well as accident prevention and mitigation measures, and makes suggestions for additional prevention and/or mitigation measures when he believes such measures are necessary.
The hazardous analysis findings are forwarded to corporate management for resolution. Implementation of mitigation options in respons
e to findings is based on relative risk ranking by the engineer. The ranking helps ensure that potential accident scenarios assigned the highest risk receive immediate attention. All approved mitigation options in response to the engineer's hazard analysis findings are tracked until they're completed. The final solution of each finding is documented and retained. Hazard analysis findings will be reviewed anytime equipment or operating procedures are changed. The results and findings from these updates will be documented and retained. Once the engineer's findings are forwarded to management for consideration, the final resolution of the findings is documented and retained.
The Sligo Plant maintains written procedures that address 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 can be used as a reference by experienced operators and provide a basis for consistent training of new employees. The procedures are periodically reviewed to ensure accuracy.
In addition, the Sligo Plant maintains written operating procedures, which are readily available to operators in the process unit and other personnel to use as necessary to safely perform their tasks.
To compliment the written procedures for process operations, the facility has implemented a comprehensive training program for all employees involved in operating a process. New employees receive basic training in facility operations if they are not already familiar with such operations. After operators demonstrate (e.g., through oral test, skills determination) adequate knowledge to perform the duties and tasks in a safe manner on their own, they can work independently. In addition, all operators periodically receive refresher training on the operating procedures to ensure that their skills and knowledge are maintained at an acceptable l
evel. The refresher training is conducted at least every three years. All of this training is documented for each operator, including the means used to verify that the operator understood the training.
The Sligo Plant has well-established practices for preventative maintenance of pressure vessels, piping systems, relief and vent systems, controls, pumps, and compressors. The basic aspects of this program include: (1) conducting training, (2) performing tests, (3) correcting identified deficiencies, and (4) applying quality assurance measures. In combination, these activities form a system that maintains the mechanical integrity of the process. Certified contractors will be used for vessel inspection and pressure relief valve testing.
Maintenance personnel receive training on (1) an overview of the process, (2) safety and health hazards, (3) applicable maintenance procedures, and (4) emergency response plans to help ensure that work is performed in a safe manner. Written procedures help ensure that work is performed in a consistent manner and provide a basis for training. Inspections and tests are performed to help to ensure that equipment function as intended and to verify that equipment is within acceptable limits (e.g., adequate wall thickness for pressure vessels). If a deficiency is identified, employees will correct the deficiency before placing the equipment back in service (if possible), or an engineer will review the use of the equipment and determine what actions are necessary to ensure the safe operation of the equipment. Another part of the mechanical integrity program is quality assurance. The 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 Sligo Plant uses a locked gate to control the entry and exit of XTO and contractor p
The Sligo Plant promptly investigates all incidents that resulted in, or reasonably could have resulted in a fire/explosion, toxic gas release, major property damage, environmental loss, or personal injury. The goal of each investigation is to determine the facts and to develop corrective actions to prevent a recurrence and forward these results to facility management for resolution. Corrective actions taken in response to the investigation team's findings and recommendations are tracked until complete. The final resolution of each finding or recommendation is documented, and the investigation results are reviewed with all employees (including contractors) who could be affected by the findings. Incident investigation reports are retained for at least 5 years so that the reports can be reviewed during hazard analyses.
To help ensure that the accident prevention program is functioning properly, the Sligo Plant conducts an audit every 3 years to determine whether the procedures and practices required by the accident prevention program are being implemented. Both hourly and staff personnel participate as audit staff members. The audit team develops findings that are forwarded to Sligo 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 Sligo Plant have hazards that must be managed to ensure continued safe operation. 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 Sligo Plant. Collectively, these prevention program activities help prevent pote
ntial accident scenarios that could be caused by equipment failures and human errors.
Specialized Safety Features
The Sligo Plant has safety features on many units to help contain/control a release and to reduce the consequences of (mitigate) a release. The following types of safety features are used in the covered processes:
Release Containment Control
1) Valves to permit isolation of the process
2) Automated bypasses and manual shutoffs for specific process parameters
3) Pressure relief valves will be properly sized and testes every 3 years. Any such valve that fails a test will be replaced or
Repaired and tested annually until engineering is satisfied that it's reliable.
4) Baseline ultrasonic testing thickness testing (for pipe corrosion) will be performed prior to startup and every 3 years
1) Local fire department has been notified about the potential hazards of the new facility and has been given the emergency
FIVE YEAR HISTORY
The Sligo Plant is a new facility so therefore, has not had any accidents within the past 5 years.
EMERGENCY RESPONSE PROGRAM INFORMATION
The Sligo Plant maintains a written emergency response program that 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 plan also covers the sequential steps of addressing a potential fire, spill, tornado, and bomb threat. The program addresses the responsibilities of each member of the emergency response team and outlines the network of communication to ensure success. When necessary, the emergency response program is updated based on modifications made to gas plant processes. The overall emergency response program for the Sligo Plant is coordinated
with the Bossier Parish Local Emergency Planning Committee (LEPC). The facility has around-the-clock communications capability with the LEPC officials. This provides a means of notifying the public of an incident.
PLANNED CHANGES TO IMPROVE SAFETY
The Sligo Plant resolves all findings from hazard analyses, some of which may result in modification to the process. At the current time, any possible recommendations from hazard analyses will be completed prior to startup of the Plant.