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Patterson Gas Plant

Parent Companies:
Plains Gas Solutions, LLC
EPA Facility ID:
Other ID:
Facility DUNS:
Parent Company DUNS:


308 Torch Lane
Patterson, LA 70392
Lat / Long:
29.726, -91.341 (Get map)
Interpolation - Satellite
Center of Facility
Horizonal accuracy:
1 m
Horizontal reference datum:
North American Datum of 1983
Source map scale:


Plains Gas Solutions, LLC
(713) 993-5400
333 Clay Street, Suite 1600
Houston, TX 77002
Foreign Address:

Person responsible for RMP implementation:

Jason Verret

Emergency contact:

Jason Verret
(985) 992-9648
24-hour phone:
(985) 399-1174
Ext or PIN:

Other contacts:

Facility (or company) email:
Facility phone:
Facility (or company) URL:


Local Emergency Planning Committee:
St. Mary Parish LEPC
Full-Time Equivalent Employees:
Covered by OSHA PSM:
EPCRA section 302:
CAA Title Air Operating Permit:
CAA Permit ID#:
OSHA Star/Merit Ranking
Last Safety Inspection Date:
April 12, 2017
Inspecting Agency:
State environmental agency
Using Predictive Filing:


Unspecified process
CBI claimed:
Program Level:
Natural Gas Liquid Extraction (211112)
Chemical name
Quantity (lbs.)
Flammable Mixture
Public OCA Chemical

RMP Preparer:

John Soenning
333 Clay Street suite 1600
Houston, TX 77002
Foreign Address:

(713) 993-5655

Latest RMP Submission:

Jan. 13, 2015
Voluntary update (not described by any of the above reasons)


Effective Date:
Other Reason:

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:

Instructions on how to make an EPA appointment can be found here.

Public OCA Chemical (in Unspecified process)
CBI claimed:
Model used:
EPA's OCA Guidance Reference Tables or Equations
Passive mitigation
  • None
not considered:
  • Blast walls

5. Flammables: Alternative release


6. Five-year accident history

No Registered Accidents

7. Prevention: Program level 3

No Prevention Program level 3

8. Prevention Program level 2

No Prevention Program level 2

9. Emergency response

Facility In Community Plan:
Facility Own Response Plan:
Specific Facility Response Plan:
Inform. Procedures in Response Plan:
Emergency Care in Response Plan:
Plan Review Date:
Response Training Date:
Dec. 10, 2014
Local Response Agency:
Local Response Agency Phone:
(985) 395-5205
Subject To - OSHA EAP:
Subject To - CWA:
Subject To - RCRA:
Subject To - OPA:
Subject To - State EPCRA:
Subject To - Other:

Executive Summary


The Patterson 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, our trained personnel will respond to control and contain the release.


The Patterson Gas Plant, located at 308 Torch Road, Patterson, LA, operates a variety of processes to produce petroleum products (e.g., natural gas, propane, butane, and condensate) from oil and gas wells. Regulated flammables handled at the Patterson Gas Plant include an NGL mix containing methane, ethane, propane, butane and pentane.


The following is a summary of the accident prevention program in place at the Patterson Gas Plant. Because processes at the Patterson Gas Plant that are regulated by the EPA Risk Management Program (RMP) regulation are also subject to the OSHA 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 program. Note that since Patterson is a Program Level 1 facility, these specific requirements are not covered under the RMP regulations, but they are listed here to demonstrate the facility overall regard for safety at the Patterson Gas Plant.

Employee Participation

The Patterson Gas Plant provides for and 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 mem
ber of a process hazard analysis (PHA) team. Employees have access to all information created as part of the Patterson 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 Patterson Gas Plant and addresses each accident prevention program element.

Process Safety Information

The Patterson 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/configuration information. Specific employees within the Patterson Gas Plant are assigned responsibility for maintaining up-to-date process safety information. This information is readily available as part of the written employee participation plan 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 (MSDS). This information specifically addresses known corrosion concerns and any known hazards associated with the inadvertent mixing of chemicals.

The Patterson 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, electrical rating of equipment, etc. 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 Patterson Gas Plant has a comprehensive progra
m 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.

The Patterson Gas Plant primarily uses the HAZOP analysis technique to perform these evaluations. 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 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 findings 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 Patterson Gas 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 finds is documented and retained.

Operating Procedures

The Patterson Gas Plant maintains written procedures that address various modes of process operations, such as (1) unit startup, (2) normal oper
ations, (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 operators. These procedures are periodically reviewed and annually certified as current and accurate. The procedures are maintained current and accurate by revising them as necessary to reflect changes made through the management of change process.


To complement the written procedures for process operations, the Patterson Gas Plant has implemented a comprehensive training program for all employees involved in operating a process. New employees receive initial training in Patterson Gas Plant 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, skill 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 Patterson 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 Patterson 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 Patterson Gas Plant evaluates contractor safety programs and performance during the selection of a contractor. Patterson Gas Plant personnel periodically monitor contractor performance to ensure that contractors are fulfilling their safety obligations.

Pre-Startup Reviews (PSR)

The Patterson Gas Plant conducts a pre-startup safety review (PSR) for any new facility or facility modification that requires a change in the process safety information. The purpose of the PSR is to ensure that safety features, procedures, personnel, and the 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. A PSR involves field verification of the construction and serves a quality assurance function by requiring verification that accident prevention program requirements were properly implemented.

Mechanical Integrity

The Patterson 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 program 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 o
f 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 job 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). If a deficiency is identified, employees will correct the deficiency before placing the equipment back into service (if possible), or a group of experts 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 Patterson 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 Patterson Gas Plant has long-standing 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 that is being worked on, (3) a procedure for safe removal of hazardous materials before process piping or equipment is opened, (4) a permit and procedure to control spark-producing activities (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 Patterson Gas Plant has a comprehensive sys
tem to manage changes that affect any 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 these changes. In addition, operating and maintenance personnel are provided any necessary training on the change.

Incident Investigation

The Patterson 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 Patterson Gas Plant management for resolution. Corrective actions taken in response to the investigation team's findings and recommendations are tracked until they are completed. 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.

Compliance Audits

To help ensure that the accident prevention program is functioning properly, the Patterson Gas Plant periodically conducts an audit to determine whether the procedures and practices required by the accident prevention program are being implemented. Both hourly and staff personnel participate as aud
it team members. The audit team develops findings that are forwarded to Patterson Gas Plant management for resolution. Corrective actions taken in response to the audit team's findings are tracked until they are completed. The final resolution of each finding is documented, and the two most recent audit reports are retained.


The processes at the Patterson Gas Plant have hazards that must be managed to ensure continued safe operations.

Universal Prevention Activities

The accident prevention program summarized previously is applied to all EPA RMP covered processes at the Patterson Gas Plant. Collectively, these prevention program activities help prevent potential accident scenarios that could be caused by (1) equipment failures and (2) human errors.

Specialized Safety Features

The Patterson 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 (mitigate) a release. The following types of safety features are used in the covered processes:

Release Detection

1) Hydrocarbon detectors with alarms in all closed compressor buildings

Release Containment/Control

1) Process relief valves that discharge to a flare/vent system to handle episodic releases

2) Valves to permit isolation of the process (manual or automated)

3) Automated shutdown systems for specific process parameter (e.g., high level, high temperature)

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

Release Mitigation

1) Fire suppression and extinguishing systems

2) Trained emergency first-responder personnel

3) Personal protective equipment

4) Spacing of equipment in accordance with IRI spacing guideline.

5) Emergency shutdowns strategically
placed around the plant that automatically shuts in the inlet and outlet and blows the plant down through the vent system.


The Patterson Gas Plant has an excellent record of accident prevention over the past five years. There have been no off-site accidents within this time period.


The Patterson Gas Plant maintains a written emergency response program, which 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 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 procedures. In addition, the Patterson 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. The emergency response program is updated as necessary. Any significant changes to the emergency response program are administered through the management of change (MOC) process, which includes informing and/or training affected personnel in the changes.

The overall emergency response program for the Patterson Gas Plant is coordinated with the Patterson Fire Department. This coordination includes periodic meetings with the local emergency response officials, local government officials, and industry representatives. The gas plant has around-the-clock communications capability with emergency response organizations (e.g., fire d
epartment). This provides a means of notifying the public of an incident, if necessary, as well as facilitating quick response to an incident. In addition, the gas plant operators are given annual refresher training for emergency response regarding the hazards of regulated substances in the gas plant.


The Patterson Gas Plant resolves all findings from PHA's, some of which may result in modifications to the process. At the current time, no changes are planned over the foreseeable future.