What is Stormwater Pollution

What is stormwater runoff?

Stormwater runoff occurs when precipitation from rain or snowmelt flows over the ground. Impervious surfaces like driveways and streets prevent stormwater from naturally soaking into the ground.

Why is stormwater runoff a problem?

Stormwater can pick up debris, chemicals, dirt and other pollutants and flow directly into a lake, stream, river or wetland. Anything that enters a storm drainage system is discharged untreated into the waterbodies we use for swimming, fishing and providing drinking water.

The effects of stormwater pollution

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 can destroy aquatic habitats. Brown Water, Green Weeds - Familiar Signs of Runoff Pollution
• 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 levels.
• Bacteria and other pathogens can wash into swimming areas and create health hazards, often making beach closures necessary.
• Debris (such as plastic bags, six-pack rings, bottles, 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 water. Managing Household Chemicals
• Polluted stormwater often affects drinking water sources, affecting human health.