Virginia Farmstead Assessment System*

Fact Sheet No. 6 Fertilizer Storage, Handling, and Management

Technical Reviewers: Kathy Dictor, Jonathan (Jay) R. Crane and Nancy K. Cook, Virginia Department of Agriculture and Consumer Services, Richmond, Virginia.

Publication Number 442-906, June 1996

*Overview of the Virginia Farm Assessment System

Table of Contents

Introduction

I. Fertilizer Storage Practices

II. Mixing and Loading Practices

III. Spills, and Cleanup and Disposal Practices

IV. Field Nutrient Management

V. Other Management Considerations

Contacts and References

Glossary No. 6

Worksheet No. 6

Introduction

Young livestock are susceptible to health problems from high nitrate-nitrogen levels as well. While most livestock can tolerate up to several times the 10 mg/l nitrate-nitrogen level, levels of 20-40 mg/l may prove harmful, especially when combined with high levels (1,000 mg/l) of nitrate-nitrogen from feed sources.

Improper handling and management of fertilizers can affect groundwater by allowing nitrate-nitrogen to seep through the ground after a leak or spill. The groundwater, and consequently the drinking water, is least likely to be contaminated if appropriate fertilizer management and handling procedures are followed. Figure 1 illustrates a well-designed facility for fertilizer storage and handling.

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I. Fertilizer Storage Practices

The storage area should have an impermeable (waterproof) floor. In the event of an accident, an impermeable floor, such as concrete, prevents fertilizer from seeping into the ground and leaching to groundwater. A dike should be built around liquid fertilizer storage areas. The dike will prevent contaminants from spreading to other areas.

Secondary containment will provide an impermeable floor and walls around the storage area, and it will prevent fertilizer from seeping into the ground if a bulk liquid fertilizer storage tank should leak. Piles of dry bulk fertilizer should be stored on an impermeable surface under cover or in a building. Dry fertilizer impregnated with a pesticide should be handled as a pesticide (see Fact Sheet No. 7).

A. BUILDING A NEW STORAGE FACILITY

1. Dry storage building or liquid secondary containment should be located downslope and at least 100 feet away from the water well or spring. Separation from the water source should be greater in areas of sand, fractured bedrock, karst, and sinkholes.

2. In the event of a fire, contaminated surface water should drain to a confined area.

3. The mixing and loading area should be close to your storage facility, to minimize the distance that chemicals are carried.

4. The building foundation or secondary containment floor should be well drained and located high above the water table. The finished soil grade should be 3 inches below the floor of the storage area and sloped away from the building to provide surface drainage. The subsoil should have a low permeability.

5. Pallets should be provided to keep bags off the floor. Dry products should bestored separately from liquids to prevent wetting from spills.

6. If you plan to store large bulk tanks, provide a large-enough containment area to confine 125 percent of the contents of the largest bulk container, plus the displaced volume of any other storage containers, fixtures and materials in the area.

7. 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.

8. Provide adequate road access for deliveries and emergency equipment.

B. MODIFYING AN EXISTING STORAGE FACILITY

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II. Mixing and Loading Practices

To contain liquid fertilizer spills and leaks when mixing and loading, an impermeable surface (suchas concrete) is required. A concrete pad should be large enough to accommodate the equipment and to contain wash water and spills when fertilizers are transferred to the sprayer.

The pad should be located adjacent to the storage area. Make sure that water moves away from the well or spring. At sites where runoff could reach the well or spring, a diversion should be constructed 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.

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 a water well or spring. 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 drain quickly through the soil. A clay surface is better than sand.

• Avoid mixing and loading near sinkholes.

• Install an anti-backsiphon device on the well and hydrants. Never put the hose in the application tank. Provide an air gap of 6 inches between the hose and the top of the application tank.

• Always supervise tank filling.

• Consider using a closed handling system, in which the fertilizer is directly transferred from the storage container to the applicator equipment, such as by a hose.

• Use rinsate for mixing subsequent loads.

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III. Spills, and Cleanup and Disposal Practices

For liquid spills, recover as much of the spill as possible and reuse as it was intended. Determine where the runoff water will flow, how to handle your particular fertilizers, and whom to call for help. Have an emergency response plan for the site.

A confined mixing and loading area, such as a sump, allows settling before transfer to rinsate storage tanks. Having several rinsate storage tanks allows you to keep rinse water from different fertilizer chemical mixes separate. That way, it can be used for mixing water on subsequent loads and not directly disposed of on the farmstead.

Availability of anhydrous ammonia, liquid fertilizers and dry bulk fertilizers have reduced the need to dispose of containers. Many people do, however, use bagged fertilizers. Bundle the bags and dispose of them in an approved landfill or disposal site.

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IV. Field Nutrient Management

Best Management Practices (BMPs) should be the basis for determining fertilization practices. BMP's that should be considered include:

1. applying fertilizer based on realistic yield or growth expectations of the crop to be grown

2. monitoringnutrient levels of soil and plant tissue, as well as irrigation water,

3. determining and crediting non-commercial fertilizer nutrient contributions such as legumes, manure and compost,

4. identification of timing and application methods for fertilizer to reduce runoff and leaching losses,

5. properly calibrating and operating fertilizer application equipment,

6. evaluating field limitations based on environmental hazards such as sinkholes, highly erodible soils, shallow aquifers, and land near surface waters, and

7. considering soil moisture conditions, particularly if applying liquid fertilizer through an irrigation system (fertigation), and taking note of impending weather conditions.

Surveys of fertilization practices in Virginia indicate that many farmers were not considering the benefits of nutrients derived from animal wastes, legume cover crops, residual nitrogen, and phosphorus and potassium buildup when applying commercial fertilizer. It is known that in many cases:

1. fertilizers are often being applied at rates many times greater than recommended by soil tests;

2. fertilizers are not being applied at the stage of plant growth that will result in maximum crop utilization; and

3. proper utilization of manure as a nutrient source, and consideration of residual nutrients in soils, and nitrogen supplied by legume crops, will maintain crop yields and result in more environmentally sound waste disposal, reduced commercial fertilizer applications, and higher farm incomes while maintaining crop yields.

In Virginia, the Integrated Nutrient Management (INM) program has been initiated to inform farmers about the benefits of improved nutrient management. The INM is based on the assumption that elimination of excess nutrients applied to the land will mean less nutrients find their way into the groundwater and surface water systems. A successful nutrient management program includes periodic soil testing to determine fertilizer needs and manure nutrient analysis to estimate the nutrient availability of the various manures.

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V. Other Management Considerations

Keeping records may seem like a task unrelated to 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 effectiveness. Purchase fertilizers only after careful and complete soil testing to determine your exact needs.

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Contacts and References

Acknowledgments

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