Which NOT among the four common land-use activities that contribute non-point source pollution?

Which NOT among the four common land-use activities that contribute non-point source pollution?

• A. Agricultural fertilizer/manure application
• B. Urban runoff from streets and parking lots
• C. Construction site erosion
• D. Industrial wastewater discharge through a dedicated pipe

Answer: (D)

The idea here is distinguishing point source pollution from non-point source pollution. Non-point pollution comes from diffuse land-use activities across a landscape and is carried to water bodies by runoff, infiltration, or wind, rather than from one specific outlet. Agricultural fertilizer and manure application, urban runoff from streets and parking lots, and construction site erosion all spread pollutants over many places and are mobilized by rain or runoff, making them non-point sources. Industrial wastewater discharge through a dedicated pipe, on the other hand, comes from a single, identifiable outfall and is a classic point source; it’s not a diffuse land-use process, so it’s the option that does not belong among the common non-point sources.

The idea here is distinguishing point source pollution from non-point source pollution. Non-point pollution comes from diffuse land-use activities across a landscape and is carried to water bodies by runoff, infiltration, or wind, rather than from one specific outlet. Agricultural fertilizer and manure application, urban runoff from streets and parking lots, and construction site erosion all spread pollutants over many places and are mobilized by rain or runoff, making them non-point sources. Industrial wastewater discharge through a dedicated pipe, on the other hand, comes from a single, identifiable outfall and is a classic point source; it’s not a diffuse land-use process, so it’s the option that does not belong among the common non-point sources.