What is a source of pollutants commonly found in stormwater runoff?

Stormwater runoff can contain a variety of pollutants, and one of the most common sources is the products that have spilled onto the ground. When it rains, these spilled substances can be washed away into storm drains and ultimately into water bodies, contributing to water pollution.

For instance, in urban areas, spills from household products like paint, fertilizers, pesticides, and cleaning agents can be particularly problematic. These substances can accumulate on surfaces such as roads, driveways, and parking lots and are easily mobilized during rain events. Therefore, the correct option emphasizes the significance of addressing product spills as a contributor to the overall pollutant load in stormwater.

Other sources of pollutants listed, while significant in their contexts, do not represent the common conditions of surface runoff as effectively as spilled products do. Wastewater treatment discharges usually refer to processed water rather than direct surface runoff, oil from vehicle leaks can indeed be a contributor but is often less prevalent than a range of spilled household products, and industrial manufacturing waste typically comes from point sources rather than being a widespread, non-point source contributor during storm events.