Munson Retail Farm Center - Executive Summary
The Andersons Munson Farm Center RMP Executive Summary |
Source and Product Description:
The Andersons Munson Farm Center is engaged in the handling, storage, application, shipping and receiving of agricultural fertilizers (liquid and granular), pesticides and miscellaneous farm supplies. This facility was purchased from The Metamora Elevator Company in the spring of 1995. The facility manager is Dave Creque
The facility occupies approximately 2 ? acres and is situated just north of the village of Munson in Medina Township, Lenawee County. The facility is located on the east side Munson Highway, north of Lawrence Street and south of the Norfolk Southern Railroad Line. There is one residence to the south side of the facility, about 30 yards away. There are no adjacent neighbors to the east. There are a couple of homes on the north, about a ? mile away. To the southwest, there are 15 houses and one church within 500 yards of the facility.
The only RMP-regulated material at this fa
cility is anhydrous ammonia. A 16,500 gallon tank and a 30,000 gallon tank are used for bulk storage of the material. These tanks are located approximately 50 feet and 65 feet, respectively, south of the railroad main line on the east side of the facility. When filled to the maximum 85% capacity, these tanks can hold 131,325 total pounds of anhydrous ammonia. This material is a gas at ambient temperature and pressure. It is a liquid when stored under pressure inside the tanks.
Anhydrous ammonia is not a poison, but it is 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 ammonia is a non-flammable gas.
Summary of Major Hazards:
The principal causes of ammonia 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
railcar or delivery truck to the bulk storage tanks or a transfer from the storage tanks to the small application tanks (aka "nurse wagons"). Flexible hoses and fixed piping must be connected properly. Hoses are date-stamped and replaced in advance of the expiration date or when defects are observed. All transfers of ammonia are observed by Anderson personnel.
Transfers from the bulk storage tanks to the nurse wagon loading station occur inside fixed steel pipes and are manually controlled. Flexible hoses are used to connect from the loading station to the nurse wagons.
With elevated temperatures that occur during mid-to-late summer, the ammonia gas inside the bulk storage tanks can expand, and possibly cause one or more relief valves to open in order to equalize the pressure inside the tank(s). 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 unlike
ly. The bulk storage tanks are built under strict guidelines established in the ASME pressure vessel code. The bulk anhydrous ammonia storage tanks are protected by concrete traffic barriers. All welding and structural work done on the tanks are performed by certified welders.
Consequences of Failure to Control the Hazards:
The worst case scenario for this facility was created using EPA's RMP Comp software. A complete release of the largest tank's contents (approximately 120,000 pounds -- creating a gas / vapor cloud) in a 10 minute period, using worst case atmospheric conditions, results in a distance to endpoint of 5.6 miles. The estimated exposed population is 5,000 people. This distance would encompass the village of Munson, the cities of Fayette and Morenci, their schools and government offices. 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 th
at 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 transfer hose failure. Prior to the excess flow valve being activated, we estimate that the maximum amount of ammonia that could escape to the atmosphere is approximately 2575 pounds. A release of this nature would likely last for about five minutes. Utilizing an average wind speed of 3.0 m/sec and atmospheric stability class D, the resulting distance to endpoint would be 0.40 miles. In this more realistic scenario, the only potential exposed receptors would be the few residences surrounding the facility - no more than 100 people.
itigation 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 Munson Farm Center are:
? Bulkhead breakaway units located on the connection point to the storage tank. If a railcar or nurse wagon were to move before properly disconnecting from the tank, the concrete structure would cause the hose to break at a safe 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 to equipment, devices or technologies that require human, mechanical or other energy input to function. Active mitigation systems in place at the Munson Farm Center are:
? Excess flow valves are located
on all outgoing liquid and vapor valves on the storage tank. 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.
? Back check valves are located on the railcar / truck unloading riser and are designed to ensure that the flow goes in one direction only. This prevents anhydrous ammonia from flowing to a railcar or truck from the storage tank.
? Pressure-relief valves are located on the top of the bulk storage tank and fixed steel piping 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 pressur
? Emergency shutoff cord, located along the side of the 30,000 gallon bulk storage tank activates the emergency shutoff valves on the discharge side of the ammonia pump. This stops the flow of ammonia by remote activation of a spring loaded valve.
? An ample supply of water is available near the bulk storage tanks from 10,000 gallon and 15,000 gallon water tanks. A nearby water well (120' away) could be utilized to provide water to knock down a vapor cloud.
? Spill control kits are located at the facility and include sorbent material, shovels, PPE and disposal containers.
? Anderson personnel and truck drivers supervise all anhydrous transfers to and from the bulk storage tank
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 spring and fall season. A good PM program is our strongest defense against a release of anhy
drous ammonia. All hose replacements are documented in the maintenance files. Records of all maintenance tasks performed on the tank or related equipment are also on file.
This facility uses Paul Akars, Inc., an Indianapolis, Indiana firm, for welding and major maintenance performed on the tank. The last complete inspection of the tank and piping was the summer of 1995. A full-scale anhydrous ammonia audit was also performed at this time. Copies of all reports are on file.
See "Steps Taken to Address Hazards" for more information on prevention measures and identification.
(see "Steps Taken to Address Hazards")
All equipment maintenance is formally documented. See the "Prevention Program" section for further explanation.
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.
All contractors receive a "contractor safety review" 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 Munson Farm Center has a number of systems in place for hazard assessment and mitigation.
The corporate 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 ma
de within 30 days and 6 months of receiving the report.
Formal investigations are performed for all environmental or safety incidents. Documentation is kept on file at the facility and the corporate Safety Department.
Monthly group safety training / 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.
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 transfer 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 c
lose 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: 911, the facility manager, the corporate Safety Department emergency phone number, the MDEQ hotline and the MDA 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 Munson Farm Center 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. Responders 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 sta
te 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 Munson Farm Center Emergency Action Plan is on file with the local fire departments.