When stormwater is absorbed into the ground, it is filtered and ultimately replenishes aquifers or flows into streams and rivers. In developed areas, however, impervious surfaces such as pavement and roofs prevent precipitation from naturally soaking into the ground. Instead, the water runs rapidly into drainage ditches, stormwater sewer systems, stormwater ponds or directly into water bodies.

What contaminates the water?
When rain enters the storm drains, it picks up whatever is on the surface and carries it directly to the stormwater ponds for treatment or directly into the adjacent water bodies, untreated. A significant part of the water quality problems in the US results from untreated stormwater runoff.  It is imperative to implement best management practices to better manage and treat stormwater runoff to protect the quality of waters in which we fish, swim and play.  Below are a few pollutants that get flushed into the water bodies:

• Antifreeze

• Car Waxes

• Cigarette butts

• Degreasers

• Detergents

• Fertilizers

• Motor Oil

• Grass clippings

• Leaves

• Pesticides

• Pet waste

Here's a few tips to remember:

• One quart of oil can contaminate up to 2 million gallons of drinking water.
• Batteries should never be stored outside where they can be exposed to precipitation and stormwater runoff. They contain acid and heavy metals and should be disposed of properly.
• Do not wash out paint cans into the storm drain.
• Car washes drain their wastewater into sewer systems so it gets treated before it is discharged back into the water system.
• Decomposing vegetative matter in storm gutters and drains leaches nutrients and can clog storm systems and result in flooding.

Pet waste can also be a source of bacteria and other pathogens in our waterways if exposed to stormwater runoff. Clean up pet waste on a regular basis.

More information is available here.