Stormwater pollution is water runoff that becomes polluted as it runs over land. It's harmful to fish, wildlife, and human health. It can lead to loss of recreational uses and loss of biological and aesthetic value.
Stormwater pollution occurs when water from rainfall, garden hoses and sprinklers picks up oils, litter, pesticides and other substances from city streets, gutters and sidewalks. The contaminated water enters the storm drain system, and from there, is carried untreated to the Bay and Estuary.
Many stormwater pollutants are invisible. However, if you see an oily sheen or turbidity on water flowing off paved surfaces, you've have seen an example of stormwater pollution.