The Dow Chemical Company, Pittsburg, CA site - Executive Summary |
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Risk Management Plan Executive Summary for The Dow Chemical Company, Pittsburg, California Site 1. Accidental Release Prevention and Emergency Response Policies The Dow Chemical Company ("Dow") is strongly committed to employee, public and environmental safety. This commitment is demonstrated by Dow's comprehensive accidental release prevention program that covers areas such as design, installation, operating procedures, maintenance, and employee training associated with the processes at the Dow site in Pittsburg, California. It is Dow's policy to implement appropriate controls to prevent possible releases of regulated substances. Dow is also committed to responding to emergencies resulting from accidental releases in order to mitigate the release and any associated consequences. 2. The Stationary Source and the Regulated Substances Handled The primary activity at Dow's Pittsburg site is agricultural chemical manufacturing. Dow has 6 regulated substances present at the Pittsburg site. These substances include: 1,3-Butadiene, ammonia (aqueous), chlorine, hydrogen chloride (anhydrous), hydrogen fluoride (anhydrous), and sulfur dioxide (anhydrous). 1,3-Butadiene is used in making emulsion polymers. Ammonia (aqueous) is used to make an agricultural herbicidal intermediate. Chlorine is used for water treatment and in making intermediate and finished products for agricultural applications. Hydrogen chloride is made as a co-product of some of the agricultural product manufacturing processes. Hydrogen fluoride and sulfur dioxide (anhydrous) are used to make agricultural products and intermediates. 3. The Worst Case Release Scenario(s) and the Alternative Release Scenario(s), including administrative controls and mitigation measures To evaluate the worst case scenarios, Dow has used the EPA's OCA Guidance Reference Tables or Equations. For alternative release scenario analyses Dow has used PHAST 5.01. The following paragraphs provide details of the results of this evaluation. The worst case release scenario submitted for all Program 3 toxic substances on site would involve an unlikely catastrophic release from the 660 Block. In a worst case scenario, 180,000 lbs. of chlorine would be released from a rail tank car. The liquid chlorine released would be assumed to form a 1 cm deep pool from which evaporation would take place. The entire pool is estimated to evaporate over 10 minutes. At Class F atmospheric stability and 1.5 m/s wind speed, the maximum distance of >25 miles is calculated corresponding to a toxic endpoint of 0.0087 mg/L. An alternative release scenario for sulfur dioxide (anhydrous) would involve an unlikely release from the 310 Block. This scenario would involve the release of 1,821 lbs. from a rupture of an unloading hose at the rail tank car unloading station. Liquid sulfur dioxide would be assumed to be released to atmosphere over a period of 1 minute. It is assumed that the release would be controlled by emergency shutdown system(s). These active mitigation systems have the effect of reducing the amount released, the duration of the release, and the consequences of a release. Under neutral weather conditions, the maximum distance to the toxic endpoint of 0.0078 mg/L of sulfur dioxide (anhydrous) would be 6.6 miles. An alternative release scenario for chlorine would involve an unlikely release from the 660 Block. The scenario would involve the release of 2,220 lbs. from a rupture of an unloading hose at the rail tank car unloading station. Liquid chlorine would be assumed to be released to form a 1 cm deep pool from which evaporation takes place. The entire pool is estimated to fully evaporate after 1 minute. It is assumed that the release would be controlled by excess flow valve(s) and emergency shutdown system(s). These active mitigation systems have the effect of reducing the amount released, the duration of the release, and the consequences of a release. Under neutral weather condition s, the maximum distance to the toxic endpoint of 0.0087 mg/L of chlorine would be 3.3 miles. An alternative release scenario for hydrogen chloride (anhydrous) involves an unlikely release from the 660 Block. This scenario involves the possible release of 1,383 lbs. from a gasket failure on a pipeline near the storage tank. Liquid hydrogen chloride would be assumed to be released to atmosphere over a period of 10 minutes. It is assumed that the release would be controlled by emergency shutdown system(s). These active mitigation systems have the effect of reducing the amount released, the duration of the release, and the consequences of a release. Under neutral weather conditions, the maximum distance to the toxic endpoint of 0.030 mg/L of hydrogen chloride (anhydrous) would be 0.46 miles. An alternative release scenario for hydrogen fluoride (anhydrous) involves an unlikely release from the 310 Block. The scenario involves the possible release of 2,715 lbs. from a flange leak on the outlet of a storage tank. Liquid hydrogen fluoride would be assumed to be released to form a pool from which evaporation takes place. The entire pool is estimated to evaporate after 20 minutes. Passive mitigation controls such as dike(s) are taken into account to calculate the scenario, having the effect of reducing the amount released and the consequences of a release. Under neutral weather conditions, the maximum distance to the toxic endpoint of 0.016 mg/L of hydrogen fluoride would be 0.24 miles. An alternative release scenario for Ammonia (concentration 20% or greater) involves an unlikely release from the 640 Block. The scenario involves the possible release of 3,480 lbs. from a gasket failure on a pipeline near the storage tank. Aqueous ammonia would be assumed to be released to form a pool from which evaporation takes place. The entire amount of ammonia in the pool is estimated to evaporate after 20 minutes leaving the water portion of the solution. Passive mitiga tion controls such as dike(s) are taken into account to calculate the scenario, having the effect of reducing the amount released and the consequences of a release. Under neutral weather conditions, the maximum distance to the toxic endpoint of 0.14 mg/L of ammonia (concentration 20% or greater) would be 0.04 miles. The worst case release scenario submitted for the only Program 3 flammable substance on site involves an unlikely catastrophic release from the 540 Block. In this scenario 180,000 lb. of 1,3-Butadiene would be released from a rupture of an unloading hose at the rail tank car unloading process. It is assumed that the entire quantity is released as a vapor, which finds an ignition source, with 10 percent of the released quantity participating in a vapor cloud explosion. Under worst case weather conditions, the calculated distance of 0.45 miles is obtained corresponding to an endpoint of 1 psi overpressure. The alternative release scenario submitted for the only Program 3 flammable substance on site involves an unlikely release from the 540 Block. The release is assumed to result in a Vapor Cloud Fire. The scenario involves the release of 24,850 lb. of 1,3-Butadiene in 10 minutes. Under neutral weather conditions, the maximum distance to the flammable endpoint of 5 kw/m2 is 0.04 miles. 4. The General Accidental Release Prevention Program The Dow Pittsburg site has taken all the necessary steps to comply with the accidental release prevention requirements set out under 40 CFR part 68 of the EPA. The Dow Pittsburg site was designed and constructed in accordance with Dow Loss Prevention Principles and Dow Engineering Standards. The following sections briefly describe the elements of the release prevention program that is in place at the Dow site. Process Safety Information Dow maintains detailed records of safety information that describe the chemical hazards, operating parameters and equipment designs associated with all processes. Examples incl ude; Material safety data sheets, piping and instrumentation diagrams, equipment specification sheets, reactive chemicals testing reports, and corrosion reports. Process Hazard Analysis Dow's Pittsburg site conducts comprehensive studies to ensure that hazards associated with the Dow processes are identified and controlled efficiently. The methodology used to carry out these analyses includes: Checklist, HAZOP, Dow Fire and Explosion Index, Dow Chemical Exposure Index, Reactive Chemical/Process Hazard Analysis, New Process Safety Subject Matter Expert Reviews, and project safety and loss prevention reviews. The studies are undertaken by a team of qualified personnel with expertise in engineering and process operations and are revalidated on a regular basis. Any findings related to the hazard analysis where a response is required are addressed in a timely manner. The most recent PHA/update was performed on November 9, 1998. Operating Procedures For the purposes of safely conductin g activities within Dow's covered processes, Dow maintains written operating procedures. These procedures address various modes of operation such as initial startup, normal operations, temporary operations, emergency shutdown, emergency operations, normal shutdown and startup after a turnaround. The information is regularly reviewed and is readily accessible to operators involved in the processes. Training Dow has a comprehensive training program in place to ensure that employees who are operating processes are competent in the operating procedures associated with these processes. Refresher training is provided at least every three years and more frequently if needed. Mechanical Integrity Dow carries out highly documented maintenance checks on process equipment to ensure proper operations. Process equipment examined by these checks includes among others: pressure vessels, storage tanks, piping systems, relief and vent systems, emergency shutdown systems, controls and pumps. Qual ified personnel with previous training in maintenance practices are utilized to carry out appropriate maintenance. These personnel are also offered specialized training as needed. The most recent review/revision of maintenance procedures was performed on May 10, 1999. Any equipment deficiencies identified by these maintenance checks are corrected in a safe and timely manner. Management of Change Written procedures are in place at Dow to safely manage changes in process chemicals, technology, equipment and procedures. Process operators, maintenance personnel or any other employee whose job tasks are affected by a modification in process conditions are promptly made aware of and offered training to deal with the modification. Pre-startup Reviews Pre-start up safety reviews related to new processes and to modifications in established processes are conducted as a regular practice at Dow. The most recent review was performed on April 1, 1999. These reviews are conducted to confirm that construction, equipment, operating and maintenance procedures are suitable for safe startup prior to placing equipment into operation. Compliance Audits Dow conducts compliance audits on a regular basis to determine whether the provisions set out under the RMP rule are being implemented. The most recent compliance audit was conducted on November 9, 1998. These audits are carried out at least every 3 years and any corrective actions required as a result of the audits are undertaken in a safe and prompt manner. Incident Investigation Dow promptly and carefully investigates any incident that has resulted in, or could reasonably result in a catastrophic release of a regulated substance. These investigations are undertaken to identify the situation leading to the incident as well as any corrective actions to prevent the release from reoccurring. All reports are retained for a minimum of 5 years. Employee Participation Dow truly believes that process safety management and accident pre vention is a team effort. Company employees are strongly encouraged to express their views concerning accident prevention issues and to recommend improvements. The site has safety teams, which involve employees as leaders in facilitating team efforts. In addition, Dow employees have access to all information created as part of the facility's implementation of the RMP rule, including information resulting from process hazard analyses in particular. Safe job performance is required for each of the jobs at Dow's Pittsburg site. Contractors On occasion, Dow hires contractors to conduct specialized maintenance, construction and various other activities. Prior to selecting a contractor, a thorough evaluation of safety performance of the contractor is carried out. Dow has a strict policy of informing the contractors of known potential hazards related the contractor's work and the processes. Contractors are also required to inform Dow of any hazards they may introduce at the site. Contract ors are also informed of all the procedures for emergency response should an accidental release of a regulated substance occur. 5. Five-year Accident History Dow has enjoyed an excellent record of preventing accidental releases over the last 5 years. Due to Dow's stringent release prevention policies, the number of accidental releases has been reduced to rates lower than the overall chemical manufacturing industry. There have been 4 accidental releases as defined by the RMP rule of regulated substances from the Dow site within the last 5 years. The first release took place on 02/27/1995 and involved less than 1 lb. of hydrogen fluoride (anhydrous). No offsite deaths or injuries occurred as a result of this accident. Onsite, there was one minor injury. Another release, of 151 lb. of hydrogen chloride (anhydrous) and 344 lb. of chlorine, occurred on 10/19/1995. The community was alerted as a precaution. No offsite deaths or injuries occurred as a result of this accident. Onsit e, there were no deaths or injuries. Another release, of less than 1 lb. of hydrogen fluoride (anhydrous), occurred on 06/21/1996. No offsite deaths or injuries occurred as a result of this accident. Onsite, there was one minor injury. Another release, of 935 lb. of chlorine, occurred on 02/02/1998. The community was alerted as a precaution. No offsite deaths or injuries occurred as a result of this accident. Onsite, there were two minor injuries. 6. Emergency Response Plan Dow utilizes a written emergency response plan to deal with accidental releases of hazardous materials. The plan includes all aspects of emergency response including adequate first aid and medical treatment, evacuations, notification of local emergency response agencies and the public, as well as post-incident decontamination of affected areas. To ensure proper functioning, Dow emergency response equipment is regularly inspected and serviced. In addition, the plan is promptly updated to reflect any pert inent changes taking place within Dow's processes that would require a modified emergency response. California Region II LEPC is the Local Emergency Planning Committee (LEPC) with which the emergency plan for the Dow Pittsburg site has been coordinated and verified. Dow also coordinates our response plans and actions with local agencies and industrial mutual aid groups, which provide Dow with additional emergency response capability. 7. Planned Changes to Improve Safety Several developments and findings have resulted from the implementation of the various elements of Dow's accidental release prevention program. Development of the Environmental, Health and Safety Work Process along with our Environmental, Health and Safety 2005 company-wide goals are some of the major steps Dow has taken to improve safety at the Pittsburg site. Additionally, we plan to continue to evaluate options for reducing the duration of accidental releases that may occur, and to improve our crisis response tra ining and procedures. |