Which is an example of non-point-source contamination of groundwater?

Which is an example of non-point-source contamination of groundwater?

• A. Pesticides that dissolve and leach through soil after it rains.
• B. A spill from a single pesticide container.
• C. A leak from a storage tank on a site.
• D. Direct discharge from a factory.

Answer: (A)

Non-point-source contamination happens when pollutants enter groundwater from many scattered sources rather than one identifiable discharge. Pesticides that dissolve and leach through soil after it rains fit this idea because rain can drive contaminants through the soil across a broad area, allowing them to seep into groundwater from numerous locations. In contrast, a spill from a single pesticide container, a leak from a storage tank on a site, or direct discharge from a factory all come from one identifiable source, making them point-source contamination. So the rainfall-driven leaching example reflects non-point-source contamination.