When used properly, chemicals should not affect water quality.  However, when improperly used, chemicals can contaminate surface water or groundwater when they drift, flow overland as runoff, or leach through the soil into groundwater.  Most water quality problems associated with pesticides and fertilizers are caused when they are spilled or improperly sprayed directly on surface water.

Some chemicals are labeled for use in or near streams, lakes or wetlands.  Still, use extra care when using chemicals in streamside areas and wetlands.

Integrated Pest Management (IPM) uses a combination of manual, mechanical, biological, chemical and preventive techniques to minimize the impact of insects, diseases and unwanted vegetation.  IPM may reduce dependence on the use of chemicals.  The Iowa Department of Agriculture and Land Stewardship regulates pesticide use in Iowa.  Please refer to the section about Pesticide Use in Appendix A.

The following best management practices describe techniques to avoid contaminating surface water and groundwater.  These guidelines complement local, state and federal regulations governing the storage, sale, transportation, handling and application of chemicals.

By federal law, chemical users must follow Environmental Protection Agency (EPA) labels on pesticides containers.

BMPs for Chemical Use and Application
· Maintain a spill containment and cleanup kit appropriate for the materials on the operation and report all spills as indicated in the manufacturer’s label instructions.

· Follow all EPA label instructions.

· Apply chemicals only under favorable weather conditions, as identified in the label instructions.

· Calibrate spray equipment to apply chemicals uniformly and in the correct quantities.

· Prevent chemical leaks from equipment.  Check all equipment for leaking hoses, connections and nozzles.

· Avoid applying herbicides in areas where the chemicals can kill stabilizing vegetation on slopes, gullies and other fragile areas subject to erosion that drain into surface water.

· Mix and load chemicals out of streamside areas; where practical, mix and load in upland areas.

· Rinse spray equipment according to manufacturer’s label instructions.  Discharge rinse water only in areas that are part of the application site.

· Dispose of surplus chemical and containers according to label instructions.

Aerial Application

· Hire a licensed aerial applicator.

· Identify and avoid streamside management areas and surface water to prevent chemicals not labeled for aquatic use from drifting over open water, or from accidentally being applied directly on the water.

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