Which statement about non-point-source contamination is true?

Which statement about non-point-source contamination is true?

• A. It results from a single accidental spill.
• B. It includes pesticides that dissolve and leach through soil after rainfall.
• C. It only occurs near industrial facilities.
• D. It cannot affect groundwater.

Answer: (B)

Non-point-source contamination comes from many diffuse sources over a wide area, not from a single identifiable discharge. When pesticides are applied on fields and rainfall occurs, some of these chemicals dissolve in water and move down through the soil. Rainwater or runoff infiltrates the soil and can carry these dissolved pesticides toward groundwater or into surface waters. This movement from numerous sources and through natural processes like infiltration is the hallmark of non-point pollution, making it a classic example to describe why pesticides that dissolve and leach through soil after rainfall fit this concept. The other statements don’t fit because a single accidental spill points to a discrete, identifiable source (point-source). Contamination isn’t limited to areas near industrial facilities; agricultural and urban areas also contribute to non-point pollution. And non-point contamination can and often does affect groundwater, so the idea that it cannot impact groundwater isn’t correct.

Non-point-source contamination comes from many diffuse sources over a wide area, not from a single identifiable discharge. When pesticides are applied on fields and rainfall occurs, some of these chemicals dissolve in water and move down through the soil. Rainwater or runoff infiltrates the soil and can carry these dissolved pesticides toward groundwater or into surface waters. This movement from numerous sources and through natural processes like infiltration is the hallmark of non-point pollution, making it a classic example to describe why pesticides that dissolve and leach through soil after rainfall fit this concept.

The other statements don’t fit because a single accidental spill points to a discrete, identifiable source (point-source). Contamination isn’t limited to areas near industrial facilities; agricultural and urban areas also contribute to non-point pollution. And non-point contamination can and often does affect groundwater, so the idea that it cannot impact groundwater isn’t correct.