Walton Wholesale and Retail Farm Center - Executive Summary |
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The Andersons Walton Wholesale & Retail RMP Executive Summary Source and Product Description The Andersons Walton Wholesale Fertilizer is engaged in the handling, storage, shipping and receiving of bulk agricultural fertilizers (liquid and granular). This facility has been operated by The Andersons, Inc. since the end of 1989. Key personnel at this facility are Keith Erny - general manager and Joe Johnson - retail manager. The facility occupies approximately 40 acres in Jackson Township, Cass County, Indiana. The plant is situated 1.5 miles south of the town of Walton on the east side of State Rt. 35 and the south side of 900 South. There are one residence across the road Walton manufactures a liquid ammonium polyphosphate fertilizer called 10-34-0 (N-P-K analysis) which is produced by combining anhydrous ammonia, phosphoric acid and water, in a controlled environment. While the process is exothermic, the resulting heat is managed through a closed-loop process that virtually elim inates the production of a steam plume. Production rates average 40,000 tons of polyphosphate fertilizer per year. Walton also produces a fertilizer solution called aqua ammonia, which is made by combining water and anhydrous ammonia. One of the RMP-regulated material involved in this fertilizer manufacturing process is anhydrous ammonia. Three 30,000 gallon tanks are used for bulk storage of the material. When filled to the maximum 85% capacity, these tanks can hold 76,500 gallons of anhydrous ammonia. This material is a gas at ambient temperature and pressure. It is a liquid when stored under pressure inside the tanks. The other RMP-regulated material at this facility is aqua ammonia. The facility manufactures aqua ammonia for resale to the farmers. Aqua ammonia is a solution containing anhydrous ammonia and water. Two one-million gallon tanks, two 56,000 gallon tanks and six 30,000 gallon tanks are used for bulk storage of the aqua ammonia. Anhydrous and aqua ammonia ar e not poisons, but they are an inhalation / respiratory hazard. Ammonia is a toxic material but it has no cumulative toxic effects on the human body. However, it is acutely corrosive when it comes in contact with mucous membranes, in particular. Anhydrous and aqua ammonia are non-flammable gases. Summary of Major Hazards The principal causes of ammonia and propane emergencies are ruptured hoses and defective valves. The most probable time for an exposure or release to occur will be during a transfer from a delivery unit (generally a tanker truck or railcar) to the bulk storage tanks or a transfer from the loading station to the nurse wagons. Flexible hoses must be connected properly. Hoses on tank trucks are date-stamped are replaced by the transporter in advance of the expiration date or when defects are observed. All transfers of ammonia are observed by Anderson personnel. Transfers from the storage tanks to the processing system or loading stations occur inside fixed steel pipes and are automated from the control room. Mass meters are used to indicate the rate of flow. With elevated temperatures that occur during mid-to-late summer, the ammonia gas inside the bulk storage tank can expand, and possibly cause the relief valve to open in order to equalize the pressure inside the tank. The relief valve will reseal itself when pressure is relieved. These "events" are very short in duration - a few seconds at the most. A complete failure or burst tank is highly unlikely. The bulk storage tanks were built under strict guidelines established in the ASME pressure vessel code. The bulk anhydrous ammonia storage tank is protected by concrete traffic barriers. All welding and structural work done on the tank or appendages are performed by certified welders. Consequences of Failure to Control the Hazards for Anhydrous Ammonia The worst case scenario for this facility was created using EPA's RMP Comp software. A complete release of the tank contents (131 ,325 pounds -- creating a gas / vapor cloud) in a 10 minute period, using worst case atmospheric conditions, results in a distance to endpoint of 6.90 miles. The estimated exposed population is 8600 people. This distance would encompass the village of Walton and surrounding residences and Lewis Cass High School. No hospitals, prisons or sensitive environmental receptors would be affected. There are no passive mitigation systems available for this type of scenario. It is our belief that the risk of a complete release of the tank contents is infinitesimally small. Active mitigation systems in place at this facility were designed to prevent or mitigate any attempts to empty the tank. The tank is in a protected location, and all transfer appendages are protected by concrete barriers. A more probable release situation is expressed by the alternative release scenario. We believe that a more likely release could occur from a tanker truck transfer hose failure. Prior to the excess fl ow valve being activated, we estimate that the maximum amount of ammonia that could escape to the atmosphere is ~ 5,600 pounds. A release of this nature would likely last for about ten minutes. Utilizing an average wind speed of 3.0 m/sec and atmospheric stability class D, the resulting distance to endpoint would be 0.50 miles. In this more realistic scenario, the only potential exposed receptors would be the residences adjacent to the facility and possibly the traffic along Highway 35, west of the facility. Active mitigation systems were included in the alternative case scenario. They are listed in the next section. Consequences of Failure to Control the Hazards for Aqua Ammonia The worst case scenario for this facility was created using EPA's RMP Comp software. A complete release of the largest aqua tank's contents (7.4 million pounds -- creating a liquid spill with ammonia vapors), using worst case atmospheric conditions, results in a distance to endpoint of 3.70 miles. The estimated exposed population is 4300 people. This distance would encompass the village of Walton and surrounding residences. No hospitals, prisons or sensitive environmental receptors would be affected. There are no passive mitigation systems available for this type of scenario. It is our belief that the risk of a complete release of the tank contents is very small. Active mitigation systems in place at this facility were designed to prevent or mitigate any attempts to empty the tank. The tank is in a protected location, and all transfer appendages are protected by concrete barriers. A more probable release situation is expressed by the alternative release scenario. We believe that a more likely release could occur from a leaking pipe. We estimate that the maximum amount of propane that could escape to the atmosphere is 10,000 pounds. Utilizing an average wind speed of 3.0 m/sec and atmospheric stability class D, the resulting distance to endpoint would be 0.30 miles. In this more realistic scenario, the only potential exposed receptors would be the residences directly adjacent to the facility. Active mitigation systems were included in the alternative case scenario. They are listed in the next section. Explanation of How Hazard Releases are Prevented. Passive mitigation refers to equipment, devices, or technologies that function without human, mechanical or other energy input. Passive mitigation systems in place at the Walton facility are: 7 Secondary containment dikes that meet or exceed regulatory standards. 7 Bulkhead breakaway units located on the connection point to the storage tanks. If a truck driver were to drive off without disconnecting from the tank, the steel structure would cause the hose to break at the outside of the connection point. At this point, active mitigation would take effect and an excess flow valve, just to the inside of the breakaway would prevent the tank from emptying to the atmosphere. Active mitigation refers t o equipment, devices or technologies that require human, mechanical or other energy input to function. Active mitigation systems in place at the Walton facility are: 7 Excess flow valves are located on all outgoing liquid and vapor valves on the storage tanks. They close automatically if the volume of gas or liquid flowing through the line exceeds the normal flow rate. They won't reopen until the downstream shutoff valve is closed and the pressure equalizes on both sides of the valve seat. Two principal causes of the excess valve closing are a ruptured hose or a broken pipe or shutoff valve downstream that is opened too quickly. 7 Back check valves are located on the unloading lines of delivery trucks and are designed to ensure that the flow goes in one direction only. This prevents anhydrous ammonia or propane from flowing to a transport tank from the storage tanks. 7 Pressure-relief valves are located on the top of the bulk storage tanks, fixed steel piping and on the vaporizer to relieve pressure that is too great. This can be caused by elevated temperatures in the summer or overfilling. They open directly to the atmosphere at 250 psig and close when the pressure inside the tank drops below this pressure. 7 An emergency shutoff cord, located along the unloading station shuts the plumbing off. 7 An ample supply of water is available near the bulk storage tank from a nearby water tank and an adjacent water well at each unloading point. 7 Spill control kits are located at the facility and include sorbent material, shovels, PPE and disposal containers. 7 Operator and truck drivers supervise all anhydrous transfers to and from the bulk storage tank Prevention Program Preventive maintenance is an integral piece of this facility's hazard management program. All hoses, tanks, valves and storage units are inspected at least monthly, and usually daily during the production season. A good PM program is our strongest defense against a release of anhydrous ammonia. All hose replacements are documented in the maintenance files. Records of all maintenance tasks performed on the tank or appendages are also on file. This facility uses Paul Akars, Inc., an Indianapolis, Indiana firm, for all welding and construction performed on the tank. The Walton processing plant undergoes a complete ammonia inspection by a third party at least every four years. The last inspection was February of 1999. See "Steps Taken to Address Hazards" for more information on prevention measures and identification. Management System (see "Steps Taken to Address Hazards") Equipment maintenance All equipment maintenance is formally documented. See the "Prevention Program" section for further explanation. Training All employees receive annual training on anhydrous ammonia, emergency action plan and spill procedures, and hazard communication. Documentation and attendance rosters are on file at the facility. Contractors All contractors receive a "contractor safety r eview" prior to performing work at the facility. During this review, they are informed of any potential hazards at the facility, emergency procedures, site-specific safety rules and the ability to request an MSDS for any product at any time. Steps Taken to Address Hazards The Andersons Walton Wholesale Fertilizer facility has many systems in place for hazard assessment and mitigation. The Safety Department performs annual hazard management audits at the facility. The audits include a physical walk through of the entire facility and a review of all EPA, OSHA and DOT paperwork and training documentation. Action items are noted and recommendations are made. The audits consist of five major topical areas: Safety & Health, Environmental, Fire Protection & Security, Administrative and Housekeeping & Storage. Issues are documented in a report and sent to the facility manager and upper management. Updates on action item status must be made within 30 days and 6 months of receiving th e report. A Process Hazard Analysis (PHA) has been made at the Walton facility, as part of their Process Safety Management Program. The analysis was performed in 1996 and will be updated every 3 years, or as changes in the process are made. A full PHA assessment will be conducted at Walton in 1999. PHA's were performed using the "what-if" technique and analyzed all aspects involved in the production of 10-34-0 fertilizer. The evaluation team included representatives from the corporate Safety Department, group Management and Operations employees. Each "what-if" situation was discussed and possible causes were listed. Unless otherwise noted, situations were evaluated under the assumption that safety controls were in effect. Potential consequences were listed and given a rating of 1 - 5 for severity and likelihood; with "1" being the worst case and "5" being "none or very low". When plotted, a risk value was assigned from 1 - 10; again with "1" being the worst and most critical item and "10" being of least consequence. Finally, results were evaluated and prioritized. Formal investigations are performed for all environmental or safety incidents. Documentation is kept on file at the facility and the corporate Safety Department. A formal Management of Change (MOC) system is administered by the Engineering Department. A form is filled out whenever a change is made to the 10-34-0 production system. Forms are routed from the facility operator to the Engineering and Safety Departments for review and remarks. A copy of the completed is form is sent back to the operator. Monthly Safety Committee meetings allow employees to discuss any concerns they may have with the operation of the facility. Issues are documented and assigned to employees for follow-up. Records of all meetings are kept at the facility. The Walton facility also participates in a "best practices" task force meeting at least three times a year to discuss production and quality issues, as well a s training and methods for continuous improvement of the process. Operators and management, together with representatives from the Safety and Engineering Departments spend the day discussing any and all issues related to the production of 10-34-0 and aqua ammonia. Response Action in the Event of a Release In the event of a burst hose or defective valve, employees are instructed to shut down the conversion process and, if possible, approach the shutoff valve from upwind and attempt to turn it off. For an uncontainable release, employees will immediately call the police and fire department or other first responders, as appropriate. All employees, customers and contractors are to be evacuated to an upwind location. Once the response team has arrived, we will work in concert with them to close the valves between the tank and the leak. In the meantime, a steady spray of water will deluge the ammonia gas plume and knock it to the ground, while chemically binding any free ammonia. The employees are instructed to make emergency phone calls in this order: the facility Manager, 911, the corporate Safety Department emergency phone number, the Indiana Emergency Response hotline and the Indiana Department of Environmental Management emergency phone number. All applicable contact names and numbers are found in the facility spill and emergency response plan. Communication procedures with responders The local fire department is invited to tour the Walton facility on an annual basis. Facility management, employees and fire department personnel have jointly discussed the location of the anhydrous ammonia and response procedures on a regular basis. They know the location of all emergency shutoff valves and on-site response equipment. We believe that a strong relationship with first responders is our best defense. The LEPC and state regulatory agencies receive a copy of our hazardous materials storage information, every February, in accordance with our community right to know obligations. A copy of the Walton Emergency Action Plan is on file with the LEPC and the local fire departments. |