Which of the following is an example of a source of point source pollution?

Point source pollution refers to contaminants that enter a waterway from a single, identifiable source. These sources are usually distinct and can be easily pinpointed, making them easier to regulate and manage.

A wastewater treatment plant discharge is a prime example of point source pollution. This discharge is a controlled outflow from a specific facility designed to treat municipal or industrial wastewater before it is released into the environment. Because the source of the pollution can be identified as the discharge point of the treatment plant, it fits the definition of point source pollution perfectly.

In contrast, runoff from agricultural fields, septic tank failures, and land erosion from construction sites represent non-point source pollution. These forms of pollution originate from multiple and diffuse sources rather than a single identifiable outlet, making their management more complex and challenging. For instance, agricultural runoff can be from various locations depending on rain events, while septic tank failures can occur at various properties scattered across a landscape, and erosion from construction sites can vary widely across different sites.