Certified in Public Health (CPH) Practice Exam

Stormwater runoff primarily contributes to which kind of environmental issue?

1. Eutrophication of water bodies

2. Loss of biodiversity in habitats

3. Declines in overall air quality

4. Increase in sedimentation in rivers

The correct answer is: Eutrophication of water bodies

Stormwater runoff plays a significant role in the eutrophication of water bodies, a process where excessive nutrients, particularly nitrogen and phosphorus, are introduced into aquatic ecosystems. When rainwater washes over urban surfaces, agricultural areas, and other land, it can pick up pollutants, including fertilizers, animal waste, and other organic compounds. These nutrients can then flow into rivers, lakes, and coastal waters, leading to an overgrowth of algae, known as algal blooms. As these algae die and decompose, their decomposition depletes oxygen in the water, creating hypoxic or anoxic conditions that can harm aquatic life, including fish and other organisms. This imbalance disrupts the natural ecosystem, leading to further environmental degradation and altering the food web. While stormwater runoff can also contribute to issues like increased sedimentation in rivers or contamination that impacts biodiversity, its primary link to eutrophication highlights the critical need to manage stormwater effectively to protect water quality in our natural bodies of water.