What is a recommended action to reduce the potential for groundwater contamination?

The recommended action to reduce the potential for groundwater contamination is to avoid disposing of leftover spray mix near wells. This is critical because wells are direct sources of drinking water, and any contaminants in the vicinity can easily leach into the groundwater that feeds into the well. By ensuring that leftover pesticides and spray mixes are disposed of properly and away from wells, the risk of contaminating the groundwater with harmful substances is significantly minimized.

The other options do not address groundwater contamination effectively. Disposing of leftover pesticides in landfills can lead to leaching of chemicals into the soil and potentially into groundwater over time, posing a risk. Applying pesticides before heavy rains can increase the likelihood of runoff, which can carry pesticides into water sources. Increasing the usage of pesticides without proper management can lead to higher concentrations of chemicals in the environment, raising the risk of contamination. Therefore, the action of avoiding disposal near wells is the most effective and responsible choice to protect groundwater resources.