What is stormwater?

Stormwater is water from rain or melting snow that does not soak into the ground. It flows from rooftops, over paved areas and bare soil, and through sloped lawns. As it flows, this runoff collects and transports soil, pet manure, salt, pesticides, fertilizer, oil and grease, leaves, litter and other potential pollutants.

You don't need a heavy rainstorm to send pollutants rushing toward streams, wetlands, lakes and oceans. A garden hose alone can supply enough water.

Even if your house is not on a waterfront, storm drains and sewers efficiently convey runoff from your neighborhood to the nearest body of water. Contrary to popular belief, most storm sewers do not carry storm water to wastewater treatment plants. Storm and sanitary sewers may be combined in some older communities.

Why should you be concerned?

Polluted storm water degrades our lakes, wetlands and rivers. Soil clouds water and degrades habitat for fish and water plants. Nutrients such as phosphorus and nitrogen promote the growth of algae, which crowds out other aquatic life. Toxic chemicals, such as antifreeze and oil from leaking cars, carelessly applied pesticides, and zinc from galvanized metal gutters and downspouts, threaten the health of fish and other aquatic life. Bacteria and parasites from pet manure can make nearby lakes and bays unsafe for wading and swimming after storms.

As many people have discovered, storm water can be a problem closer to home. It can flow into basements and cause damage that is difficult and costly to clean up. Storm water can also flow down a poorly sealed well shaft and contaminate drinking water. In areas with very porous soils or geology, pollutants in runoff may reach groundwater.

Public officials are focusing pollution control efforts on storm water management in urban and rural areas. Storm water pollution cannot be treated in the same way as water pollution from discharge pipes, because it comes from many sources.

It is carried by storm water from every street, parking lot, sidewalk, driveway, yard and garden. The problem can only be solved with everyone's help.

Pollutant	Common sources
Silt, sand, and clay particles and other debris.	Construction sites; bare spots in lawns and gardens; wastewater from washing cars and trucks on driveways or parking lots; unprotected stream banks.
Nutrients	Over-used or spilled fertilizers; pet manure; grass clippings and leaves left on streets and sidewalks; leaves burned in ditches.
Disease organisms	Pet manure and garbage.
Hydrocarbons	Car and truck exhaust; leaks and spills of oil and gas; burning leaves and garbage.
Pesticides	Pesticides over-applied or applied before a rain-storm; spills and leaks.
Metals	Cars and trucks (brakes and tire wear, exhaust); galvanized metal gutters and downspouts.

Information Courtesy: extension.missouri.edu