Marathon Oil Company - Cotton Valley Gas Plant - Executive Summary
26789 LDEQ Facility ID Number |
COTTON VALLEY GAS PLANT
RISK MANAGEMENT PLAN
ACCIDENTAL RELEASE PREVENTION AND RESPONSE POLICIES
The Cotton Valley Gas Plant (CVGP) has a long-standing commitment to safety as evidenced by over fifty years of no significant releases or failures. Preventative maintenance programs and systems are in place to reduce the potential for undesirable events. Emergency response plans and procedures are in place to handle problems if they arise. This Risk Management Plan (RMP) identifies potential release scenarios, safeguards and emergency response procedures.
CVGP: DESCRIPTION AND REGULATED SUBSTANCES
The CVGP is located just south of Cotton Valley, LA. The plant processes natural gas and condensate. Six systems process the incoming hydrocarbons; inlet separation and compression, condensate stabilization, amine system, dehydration, cryogenic system, and the fractionation train. Regulated flammable materials in natural gas such as me
thane, ethane, propane, butane, and pentane are present at the plant. Chemicals are utilized at the gas plant, however the type and quantity at the CVGP are not regulated as toxics under the RMP program.
OFFSITE CONSEQUENCE ANALYSIS RESULTS
An offsite consequence analysis was performed for both worse case and alternate release scenarios for flammable substances. The CVGP is considered one process due to the close proximity of process vessels and storage areas. Therefore, one scenario is presented for a worse case release and one for an alternate scenario release.
Worse Case Scenario (WCS)
The WCS for a flammable release was determined to be a vapor cloud explosion of a pentane storage tank. The safeguards in place to prevent an accidental release from this tank make this release scenario far from probable. Regardless of the safety systems in place, the release scenario has been developed for the worse case "what-if" scenario for the CVGP. Under the RMP regulations, a WCS for
flammable substances must consider a vapor cloud explosion event. An end point based on a one psi overpressure is required. A vapor cloud explosion involving the pentane tank could possibly affect a 0.56 mile radius around the tank.
Alternate Release Scenario (ARS)
The ARS for a flammable release was identified to be a gas release during meter proving operations. Several safety systems and practices are in place to minimize the risk of a rupture. A "what-if" scenario has been developed for emergency planning purposes. For the ARS, a 0.15 mile radius around the meter proving location could be affected.
GENERAL ACCIDENT RELEASE PREVENTION PROGRAM
The accident prevention program for the plant is summarized in the following section. The plant has a process safety management plan (PSM) in place as described in OSHA regulations. A copy of the PSM manual that describes the program is located at the CVGP. The PSM plan has been updated to include all accident prevention elements
required under RMP regulations.
Employee participation is an important aspect in process safety management. Three methods are used to involve employees in accident prevention; direct participation, active consultation with affected employees, and anonymous communication to supervisors. The process safety management program is periodically reviewed in safety meetings and employees have the opportunity to participate on hazard committees. Specific ways employees participate in the elements of the accident prevention program are described in detail in an Employee Participation Plan located in the CVGP PSM manual.
Process Safety Information
Process safety information is available in hard copy and electronic form at various locations throughout the CVGP. The Management of Change procedure is used to update Process Safety Information. MSDS sheets for all chemicals are located in several areas to describe safe handling of chemicals. Process information is doc
umented in flow diagrams that are updated in AUTOCAD by the PSM Records Processor. Process information can be found in the TRACCESS system. Safe operating information for equipment is located in the CVGP file system. Consequences of deviations are addressed in PHA. The operating procedures identify consequences of deviation, and the management of change procedure is used to update this information. A directory of the various PSM related materials is located in the PSM manual.
Process Hazard Analysis (PHA)
A multi-disciplinary team is used to conduct a PHA using a method suitable for the particular scenario. The hazard analysis includes consideration of offsite consequences to the public and environment. A study is conducted at least every five years. The Management of Change procedure is used to address recommendations and the status is reviewed quarterly. The "what-if" questions and answers are located in the CVGP training room for employee review.
erating procedures are maintained in a computerized system (TRACCESS) and printed, controlled copies available to all employees in the CVGP training room. Employees assisted in developing these procedures for tasks performed under normal, startup, and shutdown operations. A Management of Change form is completed for design or operating changes. Employees also request changes. The CVGP Records Processor circulates these change requests to management for approval. If approved, an employee will be assigned responsibility to update the procedures. The CVGP Records Processor will update the computer system to reflect the approved changes. The operating procedures are reviewed annually for content and filing accuracy.
The training system is computer based and integrated with the operating procedures. The employees utilize the TRACCESS system to review process information and procedures and pass knowledge tests for certification. The TRACCESS system also identifies expirin
g and new certifications for training tracking purposes. Practical certifications involve employees demonstrating the ability to follow procedures to CVGP supervision. Documentation is included in the computerized system. Training relating to various other safety programs are administered and tracked by the HES Department.
Contractors are required to obtain an Access and Work Permit prior to entering the CVGP. The Access and Work permit documents that the contractor understands emergency procedures, has completed general safety training, has completed a CVGP Site Specific Orientation, has completed pre-job preparation activities, utilizes proper personal protective equipment, and understands CVGP policies specific to safe work. At the end of the workday, the contractor is to check out with the designated access representative. The access representative reviews any substances the contractor brings on site to determine RMP applicability.
Pre-startup Safety Reviews (P
Pre-Startup Safety Reviews (PSSRs) are conducted by knowledgeable individuals to confirm that consideration has been given to safety prior to the startup of a process. PSSRs are required for installation of new equipment, significant modifications to existing equipment or when two or more boxes on the Safety Evaluation Checklist are checked on the Management of Change Form. The designated Project Coordinator ensures that a PSSR is conducted, develops project specific checklists, establishes a PSSR team if needed, completes the PSSR checklist, documents team participation, and files documentation.
The mechanical integrity program assures that equipment is designed, constructed, installed, and maintained to minimize the risk of releases of flammable materials. Six separate programs comprise the mechanical integrity program. The Material Specification, Material Receipt, and Tagging and Recording Procedures are all Quality Assurance Programs. These progr
ams specify equipment type, service, and minimum performance specifications, verify specifications met upon receipt of equipment, and establish a means to record equipment history. Mechanical Integrity Programs include Corrosion and Erosion Monitoring, Preventive Maintenance, and Maintenance Procedures Programs. The Corrosion Monitoring program is carried out by certified corrosion experts and includes vessel and piping inspections. The Preventative Maintenance Program is maintained on a computer- based system. The system prints weekly work orders for necessary maintenance. The PSM Records Processor will record completion dates in the computer system. The Maintenance Procedures Program is also in the computer-based system and includes a training and certification program similar to that previously described under training.
Safe Work Practices
Several safe work practices are in place to insure employee safety. Hot Work Permits are utilized when performing any task that could cr
eate a spark. Confined Space Entry Permits are utilized when employees work in areas with limited egress, unfavorable ventilation, or which is not intended for continuous employee occupancy. The Lock Out/Tag Out Program ensures that all sources of stored energy are locked out and/or tagged out before work begins. All of these programs are described in detail in Marathon Region Policies.
Management of Change
The management of change policy is a means to request, document, evaluate, and authorize all design and operating changes to ensure that they have been fully reviewed for undue risk in safety, health, operability, maintainability, environmental, and offsite areas. Design change includes any permanent or temporary installation of equipment. Operating changes are changes that require altered operating procedures and/or operating limits. A Management of Change form must be completed prior to beginning work that involves design or operating changes. This form is reviewed by CVG
P supervision. Employees will be assigned specific tasks. The CVGP Records Processor will record the completion dates. After all items are completed, the final approver will review the form. The Project Coordinator will be given a copy of the form in order to initiate the design or operating changes.
Incidents that result in, or could reasonably have resulted in a catastrophic release of flammable materials are investigated. Catastrophic releases include major uncontrolled emission, fire, or explosions involving one or more substances that present serious danger to employees or the general public or causes significant on site damage. The Plant Superintendent will assemble an investigation team to conduct an investigation within 48 hours of the incident. If a contractor is involved in an incident, an employee from that contract company will be included on the investigation team. The team's goal is to determine how, what, and why an incident occurred an
d recommend steps to prevent recurrence. A management of change sheet is to be completed for each recommendation. Incident reports will be discussed with employees at monthly safety meetings and be available for employee review.
Compliance audits are conducted at least every three years to insure that the procedures and programs developed under the accident prevention plan are adequate and are being followed. A report of findings is prepared for CVGP supervision to review. The findings, responses, and remedies are reviewed with employees and kept in the PSM files.
CHEMICAL-SPECIFIC PREVENTION STEPS
Hazards at the CVGP are managed to maintain safe operations. The following describes activities and features in place to prevent accidental releases of regulated flammable substances at the CVGP.
Universal Prevention Activities
The previously described Accident Prevention Program is applied to covered processes at the CVGP. These activities minimize potential a
ccident scenarios that could be caused by human error or equipment failures.
Specialized Safety Features
The CVGP has many safety features to contain and control, detect and mitigate releases of regulated flammable materials. The following types of safety features are used in covered processes:
7 LEL detectors with alarms
7 Process relief valves that discharge to a flare to capture and incinerate accidental releases
7 Manual and automatic valves to permit isolation of the process
7 Automated shut down systems for specific process parameters (eg. High temperature)
7 Curbing or diking to contain liquid releases
7 Redundant equipment and instrumentation (eg. Un-interruptible power supply for process control system, backup firewater pump)
7 Atmospheric relief devices
7 Fire suppression and extinguishing systems
7 Deluge system for specific equipment
7 Trained emergency response personnel
7 Personal protective equipme
FIVE-YEAR ACCIDENT HISTORY
With respect to flammables regulated under RMP, the CVGP has an excellent record of accident prevention over the past five years. No offsite events occurred during this time period. The only onsite event occurred in 1997 and resulted in a contractor injury. All events are investigated to determine ways to mitigate accident potential. Appropriate steps are taken to maintain safe and environmentally sound operations.
EMERGENCY RESPONSE PROGRAM INFORMATION
An Emergency Response Plan is maintained to protect worker and public safety, as well as the environment. This plan has been designed to address response to all emergencies including the WCS and ARS. Response strategies include detailed procedures for notification of employees, management, responders, and the public of an emergency situation. Communication, control of any releases, safety measures, and post incident recovery are included in the plan. Phone numbers for medical facilities are
included as well as pertinent Material Safety Data Sheets (MSDS) that identify safety and medical information.
The plan has been coordinated with local response organizations such as the Webster Parish LEPC, the Cotton Valley Fire Department, and the Webster Parish Sheriff's Office. The Cotton Valley Fire Department will coordinate fire department response. The sheriff's office will contact residents in the area and control access to the site.
Personnel are trained on the aspects of the plan at least annually. A schedule for performing emergency response drills as well as coordination of periodic drills with local responders is discussed in the plan. The plan is reviewed and updated at least annually.
PLANNED CHANGES TO IMPROVE SAFETY
No particular changes are planned at this time. However, safety policies and procedures are continually reviewed and updated in order to improve safety.