Improving Fertilizer Storage and Handling

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Improving Fertilizer Storage and Handling

Fertilizer Storage • Mixing and Loading • Cleanup Procedures • Container Disposal • Other Managing Practices

1. Fertilizer storage practices

If stored safely in a secure location, fertilizers pose little danger to groundwater. Common sense suggests keeping fertilizer dry and out of the way of activities that might rip open a bag or allow rain to enter a bulk container.

In the event of such an accident, an impermeable (waterproof) floor, such as properly treated concrete, helps to prevent fertilizer seeping into the ground and leaching to groundwater. A curb built around liquid fertilizer storage areas will prevent spreading to other areas.

Secondary containment provides a concrete floor and walls around the storage area, which will minimize the amount of fertilizer seeping into the ground if a bulk liquid fertilizer storage tank should leak.

A mixing/loading pad provides for secondary containment during the transfer of liquid fertilizer to application equipment or nurse tanks. Store piles of dry bulk fertilizer on a concrete pad under cover or in a building. Treat dry fertilizer impregnated with a pesticide as a pesticide. Store under cover protected from rain.

Building a new storage facility

While a new facility built just for fertilizer storage may be expensive, it may be safer than trying to adapt existing facilities and areas that are used for other purposes. Keep these simple principles in mind:

Locate the dry storage building or liquid secondary containment downslope and at least 100 feet away from the well. Separation from the well should be greater in areas of sand or fractured bedrock.
In the event of a fire, runoff water should drain to a confined area.
The mixing and loading area should be close to your storage facility, to minimize the distance that fertilizers are carried.
The storage building foundation and secondary containment floor should be well drained and above the water table. The finished grade should be 3 inches below the floor level of the storage area and sloped away from the building to provide surface drainage.
Provide plastic, rustproof pallets to keep bags off the floor. Store dry products separate from liquids or at least above them to prevent wetting from spills.
If you plan to store uncovered large bulk tanks, provide a large enough containment area to confine 125 percent of the volume of the largest bulk container, plus the volume occupied by any other storage tanks in the containment area. If bulk tanks are under cover, the containment should confine 110 percent of the volume of the largest bulk container, plus the volume occupied by any storage tanks in the containment area.
A locked storage cabinet or building provides security. Preventing unauthorized use of fertilizer reduces the chance of accidental spills or theft. Provide signs or labels indicating that the cabinet or building is a fertilizer storage area. Labels on the outside of the building give firefighters important information about fertilizers during an emergency response for a fire or spill.
Provide adequate road access for deliveries and emergency equipment.
For information on factors to consider in the design of a storage facility, such as ventilation, water access, temperature control, and worker safety, contact your county Extension office or the Midwest Plan Service at 1-800-562-3618.

Modifying an existing storage facility

You may find the above principles to be expensive and difficult to apply to your current storage, but, compared to the cost of a major accident or even a lawsuit, storage improvements are a bargain. Items 5-8 above are also important points to remember for modifying existing storage.

The cheapest alternative you may have is to cut back on the amounts stored. If that option is not practical, consider how you can protect the fertilizers you keep on hand. Sound containers are your first defense against a spill or leak. Should a bag be accidentally ripped, fertilizers should be confined to the immediate area and promptly recovered. This requires having a solid floor and, for liquid fertilizers, a curb.

Ideally, your fertilizer storage area should be separate from other activities. If the building must also serve as a machine shed or as housing for livestock, you may find it difficult to meet all the requirements for safe storage.

Stored fertilizers can pose a danger to firefighters and to the environment. Reducing the fire risk in the storage area may be the first step, but other things can be done.

You can reduce the damages by anticipating such emergencies. If a fire should occur, consider where the water will go and where it might collect. In making the storage area secure, also make it accessible, allowing you to get fertilizers out in a hurry. Label windows and doors to alert firefighters to the presence of fertilizer stored in the structure.

2. Mixing and loading practices

Groundwater contamination can result from small quantities spilled regularly in the same place. Spills of dry fertilizer should be promptly and completely cleaned up and placed immediately into the application equipment. Cleaning up spills of liquid fertilizers can be much more difficult.

A liquid fertilizer mixing and loading pad

Containing liquid fertilizer spills and leaks requires is best accomplished on a pad of properly treated concrete for mixing and loading. The pad should be large enough to accommodate your equipment and to contain leaks from bulk tanks, wash water, and spills from transferring fertilizers to the sprayer.

Locate the pad adjacent to the storage area. Make sure that all surface water moves away from the well. At sites where runoff could reach the well, construct a diversion to direct runoff to another area.

The size of the pad depends on the equipment you use. It should provide space around the parked equipment for washing and rinsing. The fertilizers and rinse water should have a confined area, such as a sump, for collecting and transfer to rinsate storage tanks. Having several separate rinsate storage tanks allows you to keep rinse water from different fertilizer mixes separate so it can be used for mixing water on subsequent loads.

If you are considering constructing a mixing/loading pad, more detailed information is available from the Midwest Plan Service at 1-800-562-3618.

Figure 1 - Diagram of Farm-Sized Fertilizer Facility showing placement of critical elements.

Better management of your existing mixing and loading site

Liquid fertilizer spills and leaks are bound to occur from time to time. Even if you don't have an impermeable mixing and loading pad, you can minimize contamination by following some basic guidelines:

Avoid mixing and loading fertilizers near your well. One way to do this is to use a nurse tank to transport water to the mixing and loading site. Ideally, the mixing site should be moved from year to year within the field of application.
Avoid mixing and loading on gravel driveways or other surfaces that allow spills to move quickly into the soil. A clay surface is better than sand.
Install an anti-backflow device on the well or hydrants. Never put the hose in the sprayer tank. Provide an air gap of 6 inches between the hose and the top of the sprayer tank.
Always supervise sprayer filling.
Consider using a closed handling system, in which the fertilizer is directly transferred from the storage container to the applicator equipment so that humans and the environment are never inadvertently exposed to the fertilizer.
Use rinsate for mixing subsequent loads, and spray the last rinsate load on the labeled crop.

3. Spill cleanup

Dry spills are usually very easily cleaned up by promptly sweeping up and reusing the fertilizer as it was intended. Dry, impregnated fertilizer is considered a pesticide and, if spilled, should be recovered and applied to the target crop as it was intended.

For liquid spills, stop the leakage and then keep the spill from spreading by building a small dike out of soil around the spill area. Clean up the spill with some kind of absorbent material; i.e., kitty litter, sawdust, or oil-soak material, and then scatter the absorbent material widely over an approved area. If deep soil contamination occurs, it is best to remove the soil and scatter it over a field.

Develop an emergency response plan for the site that includes knowing where runoff water will go, knowing how to handle your particular fertilizers, and whom to call for help. Large spill quantities of liquid or dry products that could cause damage should be reported. To report, call the 24-hour Office of Emergency Services at 1-374-1201.

4. Container disposal practices

Bulk deliveries of anhydrous ammonia, liquid fertilizers, and dry bulk fertilizers have reduced the need to dispose of containers. Many farmers do, however, use bagged fertilizers and burn the bags in the field. This practice is not recommended. Whenever possible, bundle bags and dispose of them in an approved landfill.

Your drinking water is least likely to be contaminated by your disposal practices if you follow appropriate management procedures and dispose of wastes on an approved location that is off the farm site. However, proper off-site disposal practices are essential to avoid risking contamination that could affect the water supplies and health of others.

5. Other management factors

Reducing fertilizer waste makes financial as well as environmental sense, but it means more than just reducing spills. It also means not buying more than you need to apply and keeping records of what you do have on hand. Buying only what you need makes long-term storage unnecessary.

Keeping records may seem like a task unrelated to groundwater contamination, but knowing what you've used in the past and what you have on hand allows you to make better purchasing decisions. Keep records of past field application rates and their effectiveness.

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