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

• A. Pesticides that dissolve and leach through soil after it rains
• B. A single pesticide spill into a trench
• C. A leak from a storage tank into a catchment
• D. A direct discharge from a facility

Answer: (A)

Non-point-source groundwater contamination comes from diffuse inputs over a wide area rather than a single, identifiable source. When pesticides are applied across fields and rain washes them through the soil, they dissolve and leach downward, moving with the groundwater from many locations. This makes the contamination turnout difficult to trace to one origin, which is the hallmark of non-point sources. In contrast, a spill into a trench, a leak from a storage tank, or a direct discharge from a facility all originate from a single place, making them point sources.