Living on Karst
A Reference Guide for Landowners in Limestone Regions
Produced by the Cave Conservancy of the Virginias, June 1997
Pesticides on the Home and Farm
insecticides, herbicides, rodenticide, and fungicides - are chemicals widely used by farmers, foresters, exterminators, and homeowners to kill harmful insects and weeds, to increase crop and timber harvests, and to prevent the spread of plant, animal, and human parasites and diseases.
Although targeted at pests, certain pesticides inadvertently can harm non-target organisms: stream insects, fish, wildlife, domestic animals, and humans. Pesticides can also contaminate the groundwater if not handled carefully. Pesticides can reach groundwater very quickly in karst areas due to the porous rock, sinkholes, springs, and caves.
Taking voluntary action to prevent pesticide contamination of groundwater will help assure the continued availability of pesticides for responsible use. Drinking water is least likely to be contaminated if appropriate management procedures are followed or pesticide wastes are properly disposed.
Understanding the soils on your lawn, garden, or farm and developing natural and appropriate chemical strategies can keep chemicals from leaching into your groundwater. Soil types vary widely within short distances, so several samples should be collected and analyzed in order to fully characterize the soils. Contact your county Cooperative Extension Agent for information on soil sampling and analytical services.
The correct use of pesticides and herbicides, and reducing the amount of pesticides and herbicides used can create a cost savings for the landowners.
Avoid pesticide problems by using integrated pest management practices. Such programs use chemicals only when necessary, in tandem with other practices like crop rotation, timed plantings, and appropriate growing conditions, to protect crops from weeds, insects, or diseases.
Pesticide Handling Rules
- Read and follow the label carefully.
- Buy only the quantity needed.
- Choose the least toxic pesticide. Those with the signal word Caution on the label are considered the least toxic, whereas the signal word Warning indicates moderate toxicity.
- Wear any protective clothing specified on the product label and wash hands immediately after application.
- Apply only the amount specified on the product label and only on the plants and areas listed in the instructions.
- Make sure people and pets are out of the area during application and until the spray has dried.
- Never apply to bare ground or eroded areas.
- Never store, mix, or apply near wells, streams, sinkholes, ponds, or marshes. Maintain buffer zones around these areas.
- Avoid back-siphoning from sprayer equipment into wells by always keeping the discharge end of fill hoses above the tank's water level.
- Before disposing of chemical containers, triple rinse or pressure rinse them and place the liquid rinsate into the spray tank to make up the final spray mixture.
- Prevent spills from reaching groundwater by using a mix pad with low walls to contain spills and overfills.
- Don't apply if rain is forecast, unless specified on the label (some pesticides do need to be watered after application).
- Dispose of containers and leftover pesticides according to label directions.
- Store all pesticides away from the reach of children.
- Use a "water only" nurse tank in the field - away from water sources and sinkholes - to provide water for mixing agricultural chemicals.