What effect can stormwater runoff have on water quality?

Stormwater runoff can significantly impact water quality by introducing various contaminants into rivers, lakes, and other bodies of water. When it rains, water flows over surfaces such as roads, sidewalks, and fields, picking up pollutants like heavy metals, oils, pesticides, fertilizers, and sediments. These contaminants can enter water bodies directly or through storm drains, leading to a degradation of water quality.

This influx of pollutants can alter the chemical composition of the water, necessitating changes in water treatment processes to ensure that the water is safe for consumption. Increased levels of nutrients, for instance, can lead to eutrophication, which depletes oxygen in the water and can harm aquatic life. Additionally, the presence of pathogens or toxic substances can pose serious health risks to humans and the environment.

The other options do not accurately describe the relationship between stormwater runoff and water quality. For instance, stating that it enhances treatment effectiveness overlooks the challenges posed by the contaminants introduced through runoff. Moreover, claiming that it has no impact on water quality downplays significant evidence showing the detrimental effects of pollutants. Finally, suggesting it only affects groundwater levels misses the comprehensive influence stormwater has on surface water and overall water management.