Vastar Resources, Inc. - Big Thicket Gas Plant - Executive Summary
Big Thicket Gas Plant Risk Management Plan |
ACCIDENTAL RELEASE PREVENTION AND RESPONSE POLICIES
Vastar Resources, Inc.s (Vastars) policy is to manage all operations in a manner that
protects the environment and the health and safety of employees, customers,
contractors, and the public. This 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. While prevention is our goal, if a release
does occur, trained personnel will respond to control and contain the release.
DESCRIPTION OF THE STATIONARY SOURCE AND REGULATED SUBSTANCES
Vastars Big Thicket Gas Plant, located north of Vidor, Texas, operates a variety of
processes to extract natural gas liquids from natural gas. The plant has hydrocarbon
mixtures containing regulated flammable substances including methane, ethane,
propane, n-butane, iso-butane, n-pentane, and iso-pe
ntane. The plant does not have
threshold quantities of any regulated toxic substances.
Vastar became the owner and operator of the Big Thicket Gas Plant in January, 1999.
OFFSITE CONSEQUENCE ANALYSIS RESULTS
The worst-case scenario (WCS) is failure of a 45,000-gallon storage tank containing
natural gas liquids (NGL) resulting in a vapor cloud explosion (VCE). Based on the TNT
equivalency method contained in EPAs RMP Offsite Consequence Analysis Guidance,
the WCS would impact public receptors.
The alternative release scenario (ARS) is a VCE resulting from the release of 2,900
gallons of NGL, which is the normal inventory of the 45,000-gallon storage tank. (The
NGL storage tanks are almost never filled to capacity.) While vapor cloud explosions
generally are considered unlikely events, this ARS is more likely than the WCS.
Based on flash formation factors from EPAs RMP Offsite Consequence Analysis
Guidance and a yield factor of 0.03, this ARS would not impact any public re
Further work on developing ARSs was not performed for the following reasons:
? Any ARS that would impact public receptors would impact exactly the same
receptors as the WCS.
? The only scenario which would impact public receptors is a VCE involving an
almost full inventory (say, 80 to 99 % full) of an NGL storage tank. This would not
represent a significantly more practical scenario for planning purposes as opposed
to the WCS.
GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM
The following is a summary of the accident prevention program in place at the plant.
Because processes at the gas plant that are regulated by the Environmental Protection
Agency's (EPA's) risk management program (RMP) regulation are also subject to the
Occupational Safety and Health Administration's (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
The Big Thicket Gas Plant encourages employees to participate in all facets of process
safety management and accident prevention. Examples of employee participation
range from updating and compiling technical documents and chemical information to
participating as a member of a process hazard analysis (PHA) team. Employees have
access to all information created as part of the gas plant accident prevention program.
Specific ways that employees can be involved in the accident prevention program are
documented in an employee participation plan that is maintained at the gas plant and
addresses each accident prevention program element.
Process Safety Information
The Big Thicket Gas Plant keeps a variety of technical documents that are used to help
maintain safe operation of the processes. These documents address chemical
properties and associated hazards, limits for key process parameters and specific
chemical inventories, and equipment design basis/co
nfiguration information. Specific
departments within the gas plant are assigned responsibility for maintaining up-to-date
process safety information. Reference documents are readily available as part of the
written employee participation plan and management is ready to help employees locate
any necessary process safety information. Chemical-specific information, including
exposure hazards and emergency response/ exposure treatment considerations, is
provided in material safety data sheets (MSDSs).
This information is supplemented by documents that specifically address known
corrosion concerns and any known hazards associated with the inadvertent mixing of
chemicals. For specific process areas, the gas plant has documented safety-related
limits for specific process parameters (e.g., temperature, level, composition) in a Key
Process Parameter Document. The gas plant ensures that the process is maintained
within these limits using process controls and monitoring instruments, h
personnel, and protective instrument systems (e.g., automated shutdown systems).
The gas plant also maintains numerous technical documents that provide information
about the design and construction of process equipment. This information includes
materials of construction, design pressure and temperature ratings, and electrical rating
of equipment. 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 Big Thicket Gas Plant has a comprehensive program to help ensure that hazards
associated with the various processes are identified and controlled. Within this
program, each process is systematically examined to identify hazards and ensure that
adequate controls are in place to manage these hazards.
Big Thicket Gas Plant primarily uses the hazard and operability (HAZOP) analysis
technique to perform these evaluations. HAZOP analysis is recognized as one of the
most systematic and thorough hazard evaluation techniques. The analyses are
conducted using a team of people who have operating and maintenance experience as
well as engineering expertise. This team identifies and evaluates hazards of the
process as well as accident prevention and mitigation measures, and the team makes
suggestions for additional prevention and/or mitigation measures when the team
believes such measures are necessary.
The PHA team findings are forwarded to local and corporate management for
resolution. Implementation of mitigation options in response to PHA findings is based
on a relative risk ranking assigned by the PHA team. This ranking helps ensure that
potential accident scenarios assigned the highest risk receive immediate attention. All
approved mitigation options in response to PHA team f
indings are tracked until they are
completed. The final resolution of each finding is documented and retained.
To help ensure that the process controls and/or process hazards do not eventually
deviate significantly from the original design safety features, the plant periodically
updates and revalidates the hazard analysis results. These periodic reviews are
conducted at least every 5 years and will be conducted at this frequency until the
process is no longer operating. The results and findings from these updates are
documented and retained. Once again, the team findings are forwarded to
management for consideration, and the final resolution of the findings is documented
The Big Thicket Gas Plant maintains written procedures that address various modes of
process operations, such as (1) unit startup, (2) normal operations, (3) temporary
operations, (4) emergency shutdown, (5) normal shutdown, and (6) initial startup of a
new process. Thes
e procedures can be used as a reference by experienced operators
and provide a basis for consistent training of new operators. These procedures are
periodically reviewed and annually certified as current and accurate. The procedures
are kept current and accurate by revising them as necessary to reflect changes made
through the management of change process.
In addition, the Big Thicket Gas Plant maintains a Key Process Parameter Document
that provides guidance on how to respond to upper or lower limit exceedances for
specific process or equipment parameters. This information, along with written
operating procedures, is readily available to operators in the process unit and for other
personnel to use as necessary to safely perform their job tasks.
To complement the written procedures for process operations, the Big Thicket Gas
Plant has implemented a comprehensive training program for all employees involved in
operating a process. New employees receive basic trainin
g in gas plant operations if
they are not already familiar with such operations. After successfully completing this
training, a new operator is paired with a senior operator to learn process-specific duties
and tasks. After operators demonstrate (e.g., through tests, skills demonstration) having
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 level. This refresher training is conducted at least every 3
years. All of this training is documented for each operator, including the means used to
verify that the operator understood the training.
The Big Thicket Gas Plant uses contractors to supplement its workforce during periods
of increased maintenance or construction activities. Because some contractors work on
or near process equipment,
the gas plant has procedures in place to ensure that
contractors (1) perform their work in a safe manner, (2) have the appropriate knowledge
and skills, (3) are aware of the hazards in their workplace, (4) understand what they
should do in the event of an emergency, (5) understand and follow site safety rules, and
(6) inform gas plant personnel of any hazards that they find during their work. This is
accomplished by providing contractors with (1) a process overview, (2) information
about safety and health hazards, (3) emergency response plan requirements, and (4)
safe work practices prior to their beginning work. In addition, the Big Thicket Gas Plant
evaluates contractor safety programs and performance during the selection of a
contractor. Gas plant personnel periodically monitor contractor performance to ensure
that contractors are fulfilling their safety obligations.
Pre-startup Safety Reviews (PSSRs)
The Big Thicket Gas Plant conducts a PSSR for any new facility or fa
that requires a change in the process safety information. The purpose of the PSSR is to
ensure that 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 construction is in accordance with the design
specifications and that all supporting systems are operationally ready. The PSSR
review team uses checklists to verify all aspects of readiness. A PSSR involves field
verification of the construction and serves a quality assurance function by requiring
verification that accident prevention program requirements are properly implemented.
The Big Thicket Gas Plant has well-established practices and procedures to maintain
pressure vessels, piping systems, relief and vent systems, controls, pumps and
compressors, and emergency shutdown systems in a safe operating condition. The
basic aspects of this progr
am include: (1) conducting training, (2) developing written
procedures, (3) performing inspections and tests, (4) correcting identified deficiencies,
and (5) applying quality assurance measures. In combination, these activities form a
system that maintains the mechanical integrity of the process.
Maintenance personnel receive training on (1) an overview of the process, (2) safety
and health hazards, (3) applicable maintenance procedures, (4) emergency response
plans, and (5) applicable safe work practices to help ensure that they can perform their
jobs 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 ensure that equipment functions 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
k into service (if possible), or a management of change team will review
the use of the equipment and determine what actions are necessary to ensure the safe
operation of the equipment.
Another integral part of the mechanical integrity program is quality assurance. The Big
Thicket Gas Plant 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.
Safe Work Practices
The Big Thicket Gas Plant has safe work practices in place to help ensure worker and
process safety. Examples of these include (1) control of the entry/presence/exit of
support personnel, (2) a lockout/tagout procedure to ensure isolation of energy sources
for equipment undergoing maintenance, (3) a procedure for safe removal of hazardous
substances before process piping or equipment is opened, (4) a permit and procedure
to control spark-producing a
ctivities (i.e., hot work), and (5) a permit and procedure to
ensure that adequate precautions are in place before entry into a confined space.
These procedures (and others), along with training of affected personnel, form a system
to help ensure that operations and maintenance activities are performed safely.
Management of Change
The Big Thicket Gas Plant has a comprehensive system to manage changes to all
covered processes. This system requires that changes to items such as 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 (1) ensure that adequate controls are in place
to manage any new hazards and (2) verify that existing controls have not been
compromised by the change. Affected chemical hazard information, process operating
limits, and equipment information, as well as procedures, are updated to incorporate
changes. In addition, operating and maintenance personnel are provided any
necessary training on the change.
The Big Thicket Gas Plant promptly investigates all incidents that resulted in, or
reasonably could have resulted in, a fire/explosion, major 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. The investigation team documents its findings, develops
recommendations to prevent a recurrence, and forwards these results to gas plant
management for resolution. Corrective actions taken in response to the investigation
team's findings and recommendations are tracked until they are 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 inves
tigation reports are retained for at least 5 years so that the
reports can be reviewed during future PHAs and PHA revalidations.
To help ensure that the accident prevention program is functioning properly, the Big
Thicket Gas Plant periodically conducts an audit to determine whether the procedures
and practices required by the accident prevention program are being implemented.
Compliance audits are conducted at least every 3 years. Both hourly and staff
personnel may participate as audit team members. The audit team develops findings
that are forwarded to gas plant 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
CHEMICAL-SPECIFIC PREVENTION STEPS
The processes at the Big Thicket 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 regulated substances in the
Universal Prevention Activities
The accident prevention program summarized previously is applied to all RMP-covered
processes at the Big Thicket Gas Plant. Collectively, these prevention program activities
help prevent potential accident scenarios that could be caused by equipment failures
and human errors.
Specialized Safety Features
The Big Thicket 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 processes:
1. Hydrocarbon detectors with alarms.
1. Process relief valves that discharge to a flare to capture and incinerate episodic
2. Valves to permit isolation of the process (manual or automated)
3. Automated sh
utdown systems for specific process parameters (e.g., high
4. Curbing or diking to contain liquid releases
5. Redundant equipment and instrumentation (e.g., uninterruptible power supply for
process control system, backup firewater pump)
6. Atmospheric relief devices.
1. Fire suppression and extinguishing systems
2. Deluge system for specific equipment
3. Trained emergency response personnel
4. Personal protective equipment
FIVE-YEAR ACCIDENT HISTORY
Vastar became owner and operator of the Big Thicket Gas Plant in January, 1999.
During the five months that Vastar has operated the plant, there have been no incidents
resulting from RMP regulated substances in covered processes that have caused
either: (1) onsite deaths, injuries, or significant property damage, or (2) offsite deaths,
injuries, property damage, evacuations, sheltering in place, or environmental damage.
To Vastars knowledge, there were no such incidents for at least four yea
rs, 7 months
immediately prior to Vastar becoming operator.
EMERGENCY RESPONSE PROGRAM INFORMATION
The Big Thicket Gas Plant maintains a written emergency response program, which is
in place to protect both workers and the public. The program consists of procedures for
responding to an incident, 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, and post-incident cleanup and
decontamination requirements. In addition, the 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 necess
ary to perform their specific emergency
response duties. The emergency response program is updated when necessary based
on modifications made to Big Thicket Gas Plant facilities. The emergency response
program changes are administered through the MOC process, which includes informing
and/or training affected personnel in the changes.
The overall emergency response program for the Big Thicket Gas Plant is coordinated
with the Orange County Local Emergency Planning Committee (LEPC). The plant has
around-the-clock communications capability with appropriate LEPC officials and
emergency response organizations (e.g., fire department). This provides a means of
notifying the public of an incident, if necessary, as well as facilitating quick response to
PLANNED CHANGES TO IMPROVE SAFETY
The Big Thicket Gas Plant resolves all findings from PHAs, some of which result in
modifications to the process. The following types of changes are planned over the next
few years in
response to PHA, safety audit, and incident investigation findings:
1. Upgraded process control system to use distributed computerized control system,
2. Hydrocarbon release detection system in the liquefied petroleum gas (LPG) loading
3. Revised personnel training programs, and
4. Revised written operating procedures in the amine treatment area.