Cenex/ Land O'Lakes Agronomy Center - Mason City - Executive Summary |
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Cenex/Land O'Lakes Agronomy Center - Mason City Facility Manager: Tom Worley Facility Telephone: (515) 423-4661 Accidental Release Prevention and Emergency Response Protocols: The owners, management and employees of the Mason City facility are committed to providing a safe workplace free of accidental releases of anhydrous ammonia. Health, safety and environmental compliance are a fundamental part of every employee's job. It is facility protocol to adhere to applicable Federal, State and local laws and to implement appropriate controls to prevent accidental releases of anhydrous ammonia. If an accidental release were to occur, the facility would respond in accordance with its Emergency Action Plan and is prepared to work with the local fire department, the Local Emergency Planning Committee and other authorities to control and mitigate the release and minimize the impact of the release to employees, the environment and the general public. Stationary Source and Regulated Substan ces Handled: The primary activity at this facility (the stationary source) is the storage, handling and mixing of fertilizers for direct wholesale to local cooperatives. Anhydrous ammonia is received, stored, mixed, and used for manufacturing of 10-34-0 and starter grades. The maximum stored quantity of anhydrous ammonia at the facility is approximately 130,000 pounds stored in one (1) 30,000 gallon storage tanks. The maximum fill level of each tank is 85% of the total tank capacity, which is controlled by a liquid level gauge. This facility is loaded by transport truck; therefore, the maximum quantity of anhydrous ammonia handled would occur when the on-site storage tank is at the maximum fill level of 85%. Liquid fertilizer is manufactured by combining anhydrous ammonia, super phosphoric acid, and water in a converter reactor. The super phosphoric acid is delivered in insulated rail tank cars. The super phosphoric acid is transferred to the reactor via a flexible hose to the reactor tank. The anhydrous ammonia is delivered by a high pressure gas cargo tank truck and stored in pressurized aboveground storage tank. Liquid anhydrous ammonia is pumped from the storage tank, through a meter and then through a heat exchanger where the liquid anhydrous ammonia is vaporized. After the heat exchanger, the anhydrous ammonia vapor is mixed with the water and phosphoric acid, which is pumped from the phosphoric acid rail car to the reactor. The anhydrous ammonia and phosphoric acid react to form ammonium phosphates and heat. The ammonium phosphates exit the reactor and enter a holding pool where they mix with water to form an ammonium phosphate solution (i.e., 10-34-0). Situated above the holding pool is a cooling tower with a fan that pulls air up the tower off of the holding pool. The ammonium phosphate solution is pumped to the top of the cooling tower where it flows down packing (i.e., Pall Rings) back down to the holding pool. While falling down the p acking, the water evaporates and cools the solution. Some of the ammonium phosphate solution in the holding pool is pumped out to the anhydrous ammonia heat exchanger. The warm ammonium phosphate solution is used to vaporize the anhydrous ammonia liquid from the anhydrous ammonia tank. The ammonium phosphate solution, which is cooled by the anhydrous ammonia vaporization, flows back to the holding pool and some of the solution flows to a storage tank. Worst-Case Release Scenario and Alternative Release Scenario: The worst-case release scenario would be the release of the total contents of one 30,000 gallon storage tank. The maximum quantity of anhydrous ammonia released would be approximately 130,000 pounds released in a gaseous form over ten (10) minutes. The resulting distance to the toxic endpoint concentration extends offsite and public receptors are within the distance to the endpoint. The distance to the toxic endpoint concentration (0.14 mg/L) is 1.12 miles. There was o ne (1) administrative control considered in this scenario; which is, the storage tank is not filled more than 85% full. There were no passive mitigation measures considered in this scenario. The alternative release scenario involves a release of anhydrous ammonia from a break/rupture in a two (2) inch hose during transfer of ammonia from the storage tank to the reactor or mix plant. The quantity of anhydrous ammonia released in a gaseous form would be approximately 12,000 pounds, which is based on a release rate of approximately 6,000 pounds per minute over a two (2) minute time period. The resulting distance to the toxic endpoint concentration extends offsite and public receptors are within the distance to the endpoint. The distance to the toxic endpoint concentration (0.14 mg/L) is 0.56 miles. There were no passive or active mitigation measures considered in this scenario. General Accidental Release Prevention Program and Chemical-Specific Prevention Steps: This facility comp lies with EPA's accidental release prevention requirements and applicable State and local codes and regulations. The following sections briefly describe the elements of the facility's release prevention program. 1) Safety Information: The facility was designed and constructed in accordance with applicable Federal and State regulations. All plans and procedures maintained at the facility are periodically reviewed by facility management for safety updates and changes. Material Safety Data Sheets, equipment specifications and the codes and standards used to build and operate the anhydrous ammonia equipment are maintained at the facility. 2) Hazard Review: Facility management conducts reviews of the hazards associated with the handling and storage of anhydrous ammonia. The reviews identify the opportunity for equipment malfunctions or human errors that could cause an accidental release, the safeguards used to control hazards and prevent releases, and the steps used to detect or mo nitor releases. The results of the reviews are documented and problems identified are addressed in a timely manner. 3) Operating Procedures: The facility maintains written operating procedures for the handling and storage of anhydrous ammonia. The procedures generally follow the provisions of the Occupation Safety and Health Administration (OSHA) standard, 29 CFR 1910.111, "Storage and Handling of Anhydrous Ammonia" and the American National Standards Institute (ANSI) standard, "Safety Requirements for the Storage and Handling of Anhydrous Ammonia, K-61.1". The written procedures are reviewed by facility management on a regular basis and revised as necessary. 4) Training: All employees at the facility that handle anhydrous ammonia participate in a training program. Initial training for new employees consists of classroom type instruction (e.g., reading safety information, operating procedures and response measures followed by a written test) and on-the-job supervision. Refr esher training for all employees is conducted at least once every year. The training program is reviewed by facility management on a regular basis and revised as necessary. 5) Mechanical Integrity: Written procedures are established to maintain the ongoing integrity of process equipment. Each employee involved in maintaining the ongoing integrity of process equipment is trained in an overview of that process and its hazards and in the procedures applicable to the employee's job tasks so that the employee can perform the tasks in a safe manner. Inspections and tests are performed on process equipment following recognized and generally accepted good engineering practices. The frequency of inspections and tests on process equipment is consistent with applicable good engineering practices. Documentation of each inspection and test on process equipment is maintained in the appropriate format. Deficiencies in equipment that are outside acceptable limits are corrected before further u se or in a safe and timely manner when necessary means are taken for safe operation. Appropriate checks and inspections are performed so that equipment is installed properly and consistent with design specifications and manufacture's instructions. 6) Management of Change: Written procedures are established and implemented to manage changes to process chemicals, technology, equipment, and procedures; and, changes to stationary sources that affect a covered process. The written procedures include the following considerations: technical basis of the proposed change; impact of change on safety and health; modifications to operating procedures; necessary time period for change; and, authorization requirements for the proposed change. Employees involved in operating a process and maintenance and contract employees whose job tasks will be affected by a change in the process are trained and informed of th e change prior to start-up of the process or affected part of the process. Safety information or operating procedures or practices are updated accordingly. 7) Pre-Startup Review: When modification to new stationary sources or modified stationary sources is significant enough to require a change in process safety information, a review of pre-startup safety is performed. The pre-startup safety review includes a review of the following; construction and equipment is in accordance with design specifications; safety, operating, maintenance and emergency procedures are in place and are adequate; for new stationary sources, a process hazard analysis has been performed and recommendations have been resolved or implemented before startup; and, training of each employee involved in operating a process has been completed. 8) Compliance Audits: As required by the RMP rule, compliance audits will be performed at least once every three (3) years. The audit will be documented and conducted by a person knowledgeable in the safe handling and storage of anhydrous ammonia. Corrective actions required as a result of each compliance audit will be performed promptly and documented. 9) Incident Investigation: Facility management will investigate each incident that results in, or could have reasonably resulted in a catastrophic release of anhydrous ammonia. The investigation will be performed to identify the situation leading to the incident as well as corrective actions to prevent the release from reoccurring. Investigation reports will be retained for five years. 10) Employee Participation: A written plan of action regarding employee particpation is readily accessible to workers who operate and maintain the process equipment. Employees participate in training programs and have access to information developed under the risk management program rule. 11) Hot Work Permits: Hot Work Permits are issued on an as-needed basis. Hot Work Permits are issued for all general weldi ng/fabrication purposes and electrical work. Welding/fabrication and simple routine electrical work is completed by trained facility personnel. Hot Work Permits are issued for all electrical work beyond the scope of facility personnel training to subcontractors. 12) Contractors: When the facility selects a contractor the protocol is to obtain and evaluate the safety performance of the contractor. Before access to the facility is given to the contractor, the protocol is to inform the contractor about facility hazards and the emergency response activities. Protocol for the contractor at the facility is to have safe work practices to control the entrance, presence, and exit of contract employees in covered process areas. In addition, facility protocol is to verify that the contractor is fulfilling their obligations. Five-Year Accident History: There have been no accidental releases of anhydrous ammonia in the past five (5) years that caused deaths, injuries, or significant property da mage at the facility; nor, to our knowledge, resulted in offsite deaths, injuries, evacuations, sheltering in place, property damage or environmental damage. Emergency Response Program: In the event of an emergency, it is facility protocol to notify the local fire department and other emergency responders and request that they respond to the emergency. Facility employees will not respond to accidental releases of anhydrous ammonia except for those that are small or incidental, can be controlled at the time of the release by employees in the immediate release area (e.g., shutting a valve) and do not appear to pose an immediate safety or health hazard. This protocol has been discussed with the local fire department and the other emergency responders and the facility has appropriate mechanisms in place to notify the emergency responders when there is a need for a response. The facility is also included in the written community emergency response plan developed under the Emergency Pla nning and Community Right-to-Know Act (EPCRA). Planned Changes to Improve Safety: There are no specific anhydrous ammonia safety changes planned at this time. However, safety improvement is an on-going process at this facility. Periodic evaluations are performed to assess the safety of equipment and procedures. |