What is stormwater runoff?
Stormwater runoff is water from rain or melting snow that “runs off” across the land instead of seeping into the ground. This runoff usually flows into the nearest stream, creek, river, lake or ocean. The runoff is not treated in any way.
What is polluted runoff?
On its way, runoff water can pick up and carry many substances that pollute water. Some - like pesticides, fertilizers, oil and soap – are harmful in any quantity. Others – like sediment from construction, agricultural land, pet waste, grass clippings and leaves – can harm creeks, rivers and lakes in sufficient quantities.
In addition to rain and snowmelt, various human activities like watering, car washing, and a malfunctioning septic tank can also put water onto the land surface. Here, it can also create runoff that carries pollutants to creeks, rivers and lakes.
What is Nonpoint Source Pollution?
This is another term for polluted runoff and other sources of water pollution that are hard to pinpoint. The term “nonpoint source pollution” comes from the federal Clean Water Act of 1987. There, it is used as a catch-all for all kinds of water pollution that are not well-defined discharges (point sources) from wastewater plants or industries.
How are stormwater and runoff “managed”?
“Best management practices” is a term used to describe different ways to keep pollutants out of runoff and to slow down high volumes of runoff.
Preventing pollution from entering water is much more affordable than cleaning polluted water! Educating residents about how to prevent pollution from entering waterways is one best management practice. Laws that require people and businesses involved in earth disturbing activities --like construction and agriculture -- to take steps to prevent erosion are another way to prevent stormwater pollution. There are also laws about litter, cleaning up after pets and dumping oil or other substances into storm drains.
Education and laws are just two best management practice examples. Some BMPs are constructed to protect a certain area. Some are designed to slow down stormwater, others help reduce the pollutants already in it – there are also BMPs that do both of these things.
Detention ponds are built to temporarily hold water so it seeps away slowly, fill up quickly after a rainstorm and allow solids like sediment and litter to settle at the pond bottom. Then, they release the water slowly. These ponds are one constructed BMP example. Green roofs, storm drain grates, filter strips, sediment fences and permeable paving are other examples.
What can I do to reduce the amount of stormwater pollution I contribute?
If you own a car, maintain it so it does not leak oil or other fluids. Be sure to wash it on the grass or at a car wash so the dirt and soap do not flow down the driveway and into the nearest storm drain.
If you own a yard, do not over fertilize your grass. Never apply fertilizers or pesticides before a heavy rain. If fertilizer falls onto driveways or sidewalks, sweep it up instead of hosing it away.
Mulch leaves and grass clippings and place leaves in the yard at the curb, not in the street. Doing this keeps leaves out of the gutter, where they can wash into the nearest storm drain.
Turn your gutter downspouts away from hard surfaces, seed bare spots in your yard to avoid erosion and consider building a rain garden in low-lying areas of your lawn.
If you have a septic system, maintain it properly by having it pumped every three to five years. If it is an older system, be sure it can still handle the volume placed on it today. Never put chemicals down septic systems, they can harm the system and seep into the groundwater.
Pet owners should pick up after their pets and dispose of pet waste in the garbage.
Keep lawn and household chemicals tightly sealed and in a place where rain cannot reach them.
Dispose of old or unwanted chemicals at household hazardous waste collections sites or events.
Never put anything in a storm drain.
How else can I help reduce storm water pollution in my area?
Participate in the next stream clean up in your area.
Storm drain stenciling events – where the destination of storm water is clearly marked on the drain – are a fun way to let your neighbors know the storm drain is only for rain.
Attend public hearings or meetings on the topic so you can express your concerns.
Report stormwater violations when you spot them to your local government.
Keep learning about polluted stormwater runoff and tell a friend!