Which factor is NOT typically considered as a pollutant source in stormwater management?

Natural vegetation is not typically considered a pollutant source in stormwater management because it plays a crucial role in protecting and enhancing water quality. Vegetation helps to filter and absorb rainfall, reducing runoff and trapping pollutants before they can enter waterways. It provides vital ecosystem services, such as improving soil stability, enhancing infiltration, and promoting biodiversity. In contrast, vehicle maintenance areas, construction sites, and storage areas for materials are known to introduce harmful substances, such as oils, sediment, and chemicals, into stormwater. These sources are regulated and monitored to mitigate their impact on the environment. Understanding the role of natural vegetation helps highlight the importance of maintaining green spaces within urban planning and stormwater management practices.