Certified Storm Water Operator Practice Exam

Urban runoff from impervious surfaces is a common source of stormwater pollution because these surfaces—such as roads, parking lots, and buildings—prevent water from being absorbed into the ground. Instead, during rainfall or snowmelt, water flows over these hard surfaces and picks up various pollutants, including oils, heavy metals, chemicals, and sediments. This polluted runoff is then directed into storm drains, which often lead directly to local water bodies without treatment.

This type of runoff is particularly problematic because it can lead to significant water quality issues, adversely affecting aquatic ecosystems and human health. Additionally, the rapid flow of water over impervious surfaces can lead to increased erosion and sedimentation in streams and rivers, further degrading water quality.

In contrast, while sources like wastewater treatment facilities, agricultural runoff, and industrial effluents can contribute to water quality issues, urban runoff is especially pertinent in urbanized areas, highlighting the need for effective stormwater management practices.