Arapaho Gas Plant - Executive Summary

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Arapaho Gas Processing Plant 
Butler, Oklahoma 
Custer County 
1. Executive Summary 
This summary provides a brief description of the American Central Gas Companies' (ACGC) Risk Management Plan (RMP) for the Arapaho Gas Plant in Custer County, Oklahoma. 
1.1. Accidental Release Prevention & Emergency Response Policies 
ACGC is committed to the safety of its employees and the public.  ACGC utilized generally accepted and recognized engineering practices, codes and standards in the design and construction of the Arapaho Plant.  Safe work practices have been established and written in a formal Safety & Environmental Policy Manual.  A site specific Emergency Plan has been prepared which is tailored to the facility and the resources available in the community.  Operating manuals and drawings are current for the plant. 
ACGC has a training program in place for employees assigned to the facility to ensure they can operate the  
plant safely during normal operations as well as during an emergency situation. 
1.2 Description of Arapaho Plant & Regulated Substances Handled 
The Arapaho Plant is located 9 miles North of Butler, Oklahoma in Custer County.   Its primary activity is the extraction of natural gas liquids (NGL) from a natural gas stream through the operation of a cryogenic expander unit.  Other processes at the site include compression, dehydration, and product CO2 removal to meet specifications for sales.  The plant's product, NGL, is the regulated flammable substance at the plant.  NGL is a mixture of ethane, propane, butane, pentane, and heavier hydrocarbons.  There is no storage facility for NGL product on site.  All NGL product is transported from the plant by pipeline as it is produced. 
1.3 Worst Case Release Scenario 
The Arapaho Plant is a Program 1 facility.  The worst case release scenario was determined using EPA's Off-Site Consequence Analysis (OCA) Guidance Reference Tables and Equations 
to calculate an endpoint of 1-psi overpressure.  The scenario assumed the release of the maximum volume of the product surge tank of 29,607 lbs. which forms a vapor cloud within the lower and upper flammability limits and ignites resulting in a vapor cloud explosion (VCE).  Using this scenario, the distance to a 1-psi overpressure is 0.25 miles, or 1,320 feet. 
There are no regulated toxic substances above the threshold quantity present at the Arapaho Plant. 
1.4 General Accidental Release Prevention Program 
In addition to the EPA's Risk Management Plan regulation, the Arapaho Plant is also subject to the Occupational Safety & Health Administration's (OSHA) Process Safety Management regulation. The Arapaho Plant has taken the necessary steps to comply with the accidental release prevention requirements of 40 CFR Part 68 and 29 CFR Part 1910.112. 
1.4.1 Process Safety Information 
The Arapaho Plant maintains safety information related to the process necessary to ensure the safe opera 
tion of the plant.  Examples of process safety information include, but is not limited to, Plant Operating Manual, Piping & Instrumentation Drawings (P&IDs), equipment design codes and standards, and maintenance procedures. 
In addition to this, a written Safety & Environmental Policy Manual contains policies and procedures for safe work practices.  There is also a site specific Emergency Response Plan for the facility. 
1.4.2    Process Hazard Analysis 
ACGC has conducted a Process Hazard Analysis on the Arapaho Plant in accordance with OSHA's PSM regulation.  The primary method of analysis used was the Hazard and Operability (HAZOP) method.  Recommendations from these studies are evaluated by management where a resolution and implementation schedule is developed and monitored until all are finalized.  All process changes will go through a Management of Change (MOC) review process to ensure all hazards are managed appropriately. 
1.4.2 Operating Procedures 
ACGC has developed and maintai 
ns written operating procedures that address various modes of operations such as 1) startup, 2) normal operations, 3) temporary operations, 4) normal shutdown, and 5) emergency shutdown.  These procedures can be used as a reference by experienced operators and provide a basis for consistent training of new operators.  These procedures will be revised as needed and reviewed and certified annually. 
1.4.3 Training 
ACGC has an operator & safety training program in place to train employees assigned to the facility.  New employees receive basic training in process operations followed by on-the-job supervision until they are deemed competent to work independently. 
1.4.4 Mechanical Integrity 
ACGC has a written maintenance program for the Arapaho Plant to ensure the integrity of critical equipment is maintained.  Qualified personnel perform inspections, testing, and calibration on equipment according to a predetermined maintenance schedule.  Equipment deficiencies are corrected in a safe an 
d timely manner. 
1.4.5 Contractors 
ACGC has a written Contractor Safety Policy that provides guidelines for the selection and use of contractors in the Arapaho Plant.  A Contractor's safe work practices/history is reviewed and considered to be an equal criterion for the selection process.  Outside contractors required for maintenance or construction activities receive a site specific safety orientation and accompanied by an ACGC employee to review the job prior to starting work. 
1.4.6 Incident Investigation 
ACGC has a written policy that provides for the prompt investigation of any incident that results in, or could have reasonably resulted in a catastrophic release of a regulated substance.  Investigations are designed to identify the situation leading to the incident and corrective actions needed to prevent future occurrence. 
1.5 Five-year Accident History 
The Arapaho plant is a new facility and has had no reportable accidents of a covered process. 
1.6 Emergency Response Progr 
ACGC has an Emergency Response Plan that is site specific to the Arapaho Plant.  The plan describes response procedures to minimize hazards to the public and environment in the event of a regulated substance release.  Also included in the Plan is a facility plot plan, chemical inventory, procedures for first aid and medical treatment, evacuation, control and containment of a release, and notification to local emergency response agencies. 
Emergency drills are conducted periodically within ACGC's Western Oklahoma System to provide personnel with experience in responding to simulated emergencies.  Drill scenarios vary so that personnel obtain training on a broad range of possible emergency situations.  These drills are conducted periodically, but at least annually. 
1.7 Planned Changes to Improve Safety 
ACGC has an ongoing program to monitor the safety of the Arapaho Plant.  A safety hazard reporting program is in place that provides all employees with a mechanism to submit hazards  
identified.  Reports are reviewed to determine an effective method of resolution and a formal tracking system is in place to follow up to ensure the hazard is resolved in a timely manner. 
In addition to the safety hazard reporting system, a formal facility inspection program is in place that requires scheduled inspections by a team of inspectors.  Deficiencies and recommendations resulting from these inspections are documented and tracked to ensure they are addressed in a timely manner. 
Improvements are also made as a result from programs mentioned above such as incident investigations, and mechanical integrity maintenance checks.
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