Frequently Asked Questions (FAQs)

►What is the National Pollutant Discharge Elimination System (NPDES) Storm Water Quality Management Program?
►What is stormwater, and why is it important?
►What should not enter a storm drain?
►What may enter a storm drain?
►What can I do to reduce pollution in storm water runoff?
►What are Best Management Practices (BMPs)?
►Glossary of Common Stormwater Terms

What is the National Pollutant Discharge Elimination System (NPDES) Storm Water Quality Management Program?
Mandated by Congress under the Clean Water Act, the NPDES Storm Water Quality Management Program is a comprehensive national program for addressing urban sources of storm water discharges which adversely affect the quality of our Nation's waters. The Program uses the NPDES permitting mechanism to require the implementation of controls designed to prevent harmful pollutants from being washed by storm water runoff into local water bodies.

What is stormwater, and why is it important?
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 stormwater runoff collects and transports the following pollutants:
•Sediment
•Pet waste
•Pesticides
•Fertilizer
•Automobile fluids (oil, grease, gasoline, antifreeze)
•Deicing products (road salt and fertilizers)
•Grass clippings, leaves, and other yard waste
•Cigarette butts
•Other litter

Storm drains efficiently convey runoff from your neighborhood to the nearest body of water. Consider a rooftop connected to a gutter system that is adjacent to a sidewalk. This sidewalk may drain to a concrete-lined storm drain leading to a stream. This system can quickly transport pollutants into our rivers and streams. This series of connected impervious areas may be thought of as a "stormwater superhighway". Contrary to popular belief, storm drains do not carry stormwater to wastewater treatment plants - storm drains directly lead to streams and eventually the ocean.

Polluted stormwater degrades streams, rivers, ponds, wetlands, estuaries, sounds, and bays. Soil clouds water and deteriorates habitat for fish and plants. Nutrients such as nitrogen and phosphorus promote the growth of algae, which crowd 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, also threaten the health of fish and other aquatic life. Bacteria and parasites from pet waste and leaking septic tanks can make lakes and the ocean unsafe for wading and swimming after storms.

Across the country, public officials are directing their pollution control efforts to stormwater management in urban and rural areas. Preventing stormwater pollution presents unique challenges since pollutants come from many sources (see table below). Pollutants are carried by runoff from every street, parking lot, sidewalk, driveway, yard, and garden. The problem can only be solved with everyone's help!

Common Sources of Stormwater Pollutants
Pollutant Sources
Silt, sand, and clay Construction sites; bare spots in lawns and gardens; wastewater from sediment and other debris; washing cars and trucks on driveways or parking lots; dirt roads and driveways; unprotected streambanks and drainageways
Nutrients Fertilizers; pet waste; grass clippings and leaves left on streets and sidewalks; leaves burned in ditches; atmospheric deposition
Disease organisms Pet and wildlife waste; garbage
Hydrocarbons Car and truck exhaust; leaks and spills of oil and gas; used oil dumping; burning leaves and garbage
Pesticides Pesticides overapplied or applied before a rainstorm; spills and leaks
Metals Cars and trucks (brake and tire wear, exhaust); galvanized metal gutters and downspouts; industrial activities

What should not enter a storm drain?
•Oil, anti-freeze, paint, cleaning fluids
•Wash water from a commercial car wash
•Industrial discharges
•Wash waters from commercial/industrial activities
•Contaminated foundation drains
•Sanitary sewer discharges
•Septic tank discharges
•Washing machine discharges
•Chlorinated backwash and draining associated with swimming pools

What may enter a storm drain?
Surface water
•Diverted stream flows
•Springs
•Flows from riparian habitats and wetlands

Ground water
•Uncontaminated rising ground water
•Uncontaminated ground water
•Foundation drains
•Water from crawl space pumps
•Footing drains

Potable water
•Irrigation water
•Landscape irrigation
•Lawn watering
•Dechlorinated backwash and draining associated with swimming pools
•Fire fighting emergency activities
•Single residential car washing

What can I do to reduce pollution in storm water runoff?
Everybody can reduce pollution in stormwater by implementing a few good "housekeeping" practices.
•Maintain your automobile.
•Regular car maintenance can reduce oil drippings and other pollutants on the road.
•Use biodegradable products for landscaping, car washing, etc.
•Keep storm drains and street gutters clear of debris.
•Bag or mulch lawn clippings so they won't wash into nearby storm drains.
•Clean up after your pets.
•Store and dispose of household chemicals properly. Always use them in the way they were intended. Seal the product to prevent leakage. Take unwanted hazardous wastes to a proper disposal facility.
•Don't treat roofs or driveways with toxic chemicals used for cleaning or moss retardation.
•Plant native vegetation
•Reduce your use of fertilizers, herbicides and pesticides in your yard and garden. If you do apply fertilizer and chemicals to your lawn, follow the application instructions found on the label.

What are Best Management Practices (BMPs)?
Best Management Practices (BMPs) are activities, practices, maintenance procedures, and other management practices designed to prevent or reduce the pollution of waters of the United States. BMPs also include treatment technologies, operating procedures, and practices to control plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw sewage. BMPs may include structural devices or nonstructural practices.