Certified Crop Advisor Practice Exam

Which type of pesticide is most likely to move into groundwater?

1. Biodegradable

2. Soluble and persistent

3. Non-soluble and volatile

4. Localized and short-lived

The correct answer is: Soluble and persistent

The type of pesticide that is most likely to move into groundwater is one that is soluble and persistent. Pesticides that are soluble can easily dissolve in water, which facilitates their movement through the soil profile and into aquifers. If a pesticide is also persistent, it means that it does not break down easily in the environment, allowing it to remain in the soil and water for an extended period. This combination increases the likelihood of the pesticide leaching into groundwater sources, posing potential risks to water quality and public health. While biodegradable pesticides can break down more rapidly, their tendency to be less soluble means they are less likely to reach groundwater in significant amounts. Non-soluble and volatile pesticides tend to remain in the soil or evaporate into the air rather than leach into groundwater. Localized and short-lived pesticides are designed to be effective only in specific areas and degrade quickly, which further reduces the potential for groundwater contamination. Therefore, a combination of water solubility and persistence is key in understanding the movement of pesticides into groundwater systems.