Storm drains (like those found along curbs) do not go to wastewater treatment plants. Water entering storm drains flows untreated into streams, rivers, ponds, wetlands, lakes, sounds, bays, and oceans.
Stormwater picks up and carries numerous pollutants into our waterways. Many of these pollutants can cause problems in very small amounts. Polluted stormwater runoff is so varied and so widespread that it is very difficult to address its sources.
Did you know that sediment is the number-one pollutant in the country? Sediment comes from anywhere soil is disturbed and is allowed to enter waterways. When it is suspended in the water, it clouds water and suffocates aquatic life. When it settles out of water, it deteriorates habitats for fish and plants by burying stream riffles, which add oxygen to water.
Fertilizers are water pollutants as well. Fertilizers contain nitrogen and phosphorus, which promote algae growth. Excess algae crowds out other aquatic life and can cause a water body have insufficient oxygen. This lack of oxygen is one of the primary causes of fish kills. Excess nutrients have also been linked to developmental defects in amphibians.
Antifreeze and oil from cars, pesticides, and metal particles are all toxic to fish and other aquatic life. Bacteria and parasites from pet waste and leaking septic tanks can make nearby lakes and bays unsafe for recreational use and have caused many waters to be closed to shellfish harvesting. Stormwater runoff can also contaminate wells and groundwater.
In larger amounts, excess stormwater causes flooding and damage to the environmentthat is difficult and costly to clean up.
Because polluted runoff is caused by so many of our everyday activities, we all need to do our part to help improve water quality.