Williams Gas Processing -- Ignacio Plant - Executive Summary |
|
EXECUTIVE SUMMARY IGNACIO PLANT RISK MANAGEMENT PLAN ACCIDENTAL RELEASE PREVENTION AND RESPONSE POLICIES The employees at the Ignacio Gas Conditioning Plant are strongly committed to EMPLOYEE, PUBLIC and ENVIRONMENTAL SAFETY. The commitment is demonstrated by conforming to our Process Safety Management Program and various resources invested in accident prevention. "MOCK" emergency drills are conducted monthly and specific training of our personnel is required in order to eliminate the occurrence of possible hazards. These goals are achieved with every project design, installation, operation and maintenance of our processes. Our policy is to implement the appropriate controls to prevent any possible release of our regulated substances to surrounding public domains, existing waterways and/or animal habitats. The Emergency Operating Procedure (EOP) manual utilized at the Ignacio facility includes designated procedures mandated by the Willia ms management group. These specific procedures are for notification of agencies, evacuation of public receptors and response of trained personnel to control and contain the release. THE STATIONARY SOURCE AND REGULATED SUBSTANCES The Ignacio Gas Conditioning Plant is located in a rural area of La Plata County, Colorado, on Section 36, Township 34 north, Range 9 west NMPM, 10 miles southeast of Durango, Colorado, 1 = miles west of the La Plata County airport along County Road 307. We have three regulated substances present at our facility; they include methane, ethane, and butane all of which are extracted from the inlet natural gas stream. Listed below are the maximum inventory quantities: Methane - 194,000 lbs. Ethane - 487,000 lbs. Butane - 2,441,000 lbs.. WORST CASE RELEASE SCENARIO AND ALTERNATIVE RELEASE SCENARIO The Worst Case Scenario (WCS) for the Ignacio Plant is a vapor cloud explosion involving a product storage tank of B utane to be overfilled. In the scenario, 123,959,889 lbs. of Butane would be released resulting in an explosion calculated to cause a 1-psi pressure increase at an endpoint distance of 0.86 miles. The offsite impact of this scenario involves approximately 50 public receptors and two other industrial facilities; no environmental receptors were identified. The EPA's Offsite Consequence Analysis (OCA) guidance reference tables/equations were used to model this scenario. Clearly, this hypothetical situation is highly unlikely. Given the safe work procedures employed at the Ignacio plant the normal operating level of this product storage tank is 66% with administrative controls calibrated to alarm at 88%. A passive mitigation is currently utilized in our product storage area to eliminate any pooling of flammable liquids and a fire water system with monitors, which are tested/certified annually to ensure reliability. The Alternative Release Scena rio (ARS) involves the same storage tank at normal operating conditions. This scenario depicts a gasket failure on the piping attached to the tank and releasing approximately 2,538 lbs. in a period of 45 minutes. With Butane being a heavy gas the downwind hazard would result in a vapor cloud fire 78 feet in diameter, with no public, industrial or environmental receptors identified. This fire would trigger the ultra violet detection in the area of the tank farm and immediately alarm the control room and Emergency Shutdown (ESD) the facility. The ARCHIE software utilized by WILLIAMS in this modeling is recognized to be sufficient by the EPA. GENERAL ACCIDENTAL RELEASE PREVENTION PROGRAM AND CHEMICAL SPECIFIC PREVENTION STEPS The Ignacio Gas Conditioning Plant is a facility that is covered by Process Safety Management (PSM) regulations (OSHA 1910). The essential provision of PSM is Process Hazard Analysis (PHA)- a careful review of what could go wrong and wh at safeguards must be implemented to prevent releases of hazardous chemicals. Through a series of PHAs, all the covered processes have been reviewed to ensure accuracy. The PHAs are revalidated in accordance with OSHA regulations every four years. The PSM program of the plant requires a systematic approach in evaluating the entire process. The approach addresses the process design, process technology, process changes operational and maintenance activities and procedures, non-routine activities and procedures, emergency preparedness plans and procedures, training programs, and other elements that affect the process are all considered in the evaluation. To assist the location in the implementation of the PSM program the plant has assigned a person to the sole responsibility of PSM coordinator, and this person is responsible directly to management. EMERGENCY RESPONSE PROGRAM INFORMATION The Ignacio Plant maintains a written emergency response program t o safeguard plant personnel, the public safety as well as the environment. The program consists of procedures for responding to a regulated substance release, including the possibility of a fire and/or explosion associated with an accidental release of a flammable substance. The procedures address all aspects of emergency response, including evacuation plans, accounting for personnel after an evacuation, and notification of local emergency response agencies and the public if a release occurs. Employees receive monthly training in these procedures to perform emergency response duties. The program is updated annually due to possible modifications made to the gas plant. These changes are administered through the Management of Change (MOC) process and our Salt Lake office. The overall emergency response program for the Ignacio Plant is coordinated with the Local Emergency Planning Committee (LEPC). This coordination includes attending periodic meetings of the LEPC committee, composed of local emergency response officials and industry representatives. The facility has 24-hour communications capability with La Plata County's LEPC, along with offering the local fire department and other emergency response organizations the opportunity to participate in periodic "MOCK" emergency drills. Ignacio Plants EOP manual is also updated annually and delivered to our emergency response officials and various industry representatives. FIVE-YEAR ACCIDENT HISTORY We have not had a single release of a regulated substance at the Ignacio facility within the last five years. This accomplishment is attributed to the stringent release prevention policy mandated by the Williams management group and executed by each employee. PLANNED CHANGES TO IMPROVE SAFETY Critical emergency equipment such as the existing fire pump will be reviewed to assure long-term operability and reliability. Replacement, due to obsolescence or spare part unavailability, will be performed where warranted. |