Which of the following is an example of point-source pollution?
A. Fertilizer from agricultural runoff B. Water from a sewage treatment plant C. Salt from roads D. Acid from abandoned mines
The Correct Answer and Explanation is :
The correct answer is B. Water from a sewage treatment plant.
Explanation:
Point-source pollution refers to contaminants that enter a waterway from a single, identifiable source, often through a direct discharge. This is distinct from nonpoint source pollution, which arises from diffuse sources that cannot be traced back to a single point.
In this context, water from a sewage treatment plant is considered point-source pollution because it is discharged through a specific outlet or pipe. The sewage treatment process typically involves collecting wastewater from homes, industries, and other facilities, treating it to remove pollutants, and then releasing it back into a water body. Although the effluent is treated to reduce its environmental impact, it can still contain nutrients, pathogens, and other contaminants that may affect water quality and aquatic ecosystems.
The other options presented represent different types of pollution:
- A. Fertilizer from agricultural runoff is an example of nonpoint source pollution. It typically enters waterways through rain or irrigation, washing excess fertilizers off fields and into nearby streams, lakes, or rivers, making it difficult to trace back to a single source.
- C. Salt from roads also qualifies as nonpoint source pollution. When roads are salted to manage ice and snow, the salt can wash into storm drains and water bodies during precipitation events, contributing to increased salinity levels in these ecosystems.
- D. Acid from abandoned mines can be considered a point source when it is discharged from a specific location, such as an old mining site, but it is often more accurately categorized as nonpoint source pollution because it typically leaches into the environment over a wide area without a single identifiable discharge point.
Thus, the most clear-cut example of point-source pollution from the options given is the treated water discharged from a sewage treatment plant.