Certified Storm Water Operator Practice Exam

Urban stormwater runoff is often contaminated by a variety of pollutants that are generated from human activities and urban infrastructure. One of the most common pollutants found in this runoff is oil and grease from vehicles.

As vehicles operate, they release substances such as motor oil, gasoline, and lubricants. When it rains, these pollutants are washed off the roads and parking lots, entering the stormwater system and ultimately affecting nearby water bodies. The presence of oil and grease in stormwater can severely impact water quality, leading to issues such as decreased oxygen levels, harm to aquatic life, and potential health risks for humans who may come into contact with contaminated water.

In contrast, while pesticides from agricultural fields do contaminate stormwater, they are more characteristic of rural or agricultural runoff rather than urban environments. Sediments from riverbanks are typically more associated with erosion than with urban stormwater runoff, and organic matter from natural bodies of water is less indicative of urban sources. Therefore, oil and grease represent a prevalent and relatively unique pollutant linked specifically to urban settings, making it the correct answer in this context.