Oregon Pesticide Practice Test

True or false: Pesticides that dissolve and leach through the soil after it rains is an example of non-point source contamination.

1. True

2. False

3. Only during heavy rainfall

4. Depends on the pesticide type

The correct answer is: True

When considering the nature of non-point source contamination, it is essential to understand what it entails. Non-point source contamination refers to pollutants that do not originate from a single, identifiable source but instead come from various sources that are difficult to pinpoint. In the case of pesticides that dissolve and leach through the soil after rain, the rainwater can carry these dissolved substances away from agricultural fields or other areas where pesticides were applied. As rainwater runs off the landscape and percolates through the soil, it can transport pesticides into waterways, groundwater, or surrounding environments, making it challenging to track their origin. This process exemplifies non-point source contamination because the source of the pesticide is dispersed over a wider area rather than originating from a specific spill or point of application. By contrast, point source contamination would involve a specific, identifiable location—such as a pesticide storage facility leaking into a nearby stream. The leaching of pesticides through soil following rain demonstrates how environmental factors can contribute to widespread contamination, characteristic of non-point sources. Thus, labeling such leaching as non-point source contamination is accurate and reflects the broader implications of pesticide use in agricultural and urban settings.