What is Stormwater?
Stormwater runoff occurs when precipitation from rain or snowmelt flows over
the ground. Impervious surfaces like driveways, sidewalks, and streets prevent stormwater from naturally soaking
into the ground.
Stormwater can pick up debris, chemicals, dirt, and other pollutants and flow into a storm sewer system or directly
to a lake, stream, river, wetland, or coastal water. Anything that enters a storm sewer system is discharged
untreated into the waterbodies we use for swimming, fishing, and providing drinking water.
Polluted stormwater runoff can have many adverse effects on plants, fish, animals, and people.
- Sediment can cloud the water and make it difficult or impossible for aquatic plants to grow. Sediment also
candestroy aquatic habitats.
- Excess nutrients can cause algae blooms. When algae die, they sink to the bottom and decompose in a process that
removes oxygen from the water. Fish and other aquatic organisms can't exist in water with low dissolved oxygen
- Bacteria and other pathogens can wash into swimming areas and create health hazards, often making beach closures
- Debris—plastic bags, six-pack rings, bottles, and cigarette butts—washed into waterbodies can choke, suffocate,
or disable aquatic life like ducks, fish, turtles, and birds.
- Household hazardous wastes like insecticides, pesticides, paint, solvents, used motor oil, and other auto fluids
can poison aquatic life.
- Land animals and people can become sick or die from eating diseased fish and shellfish or ingesting polluted
- Polluted stormwater often affects drinking water sources. This, in turn, can affect human health and increase
drinking water treatment costs.
The above information was provided from the EPA's CU After the Storm Brochure