DID YOU KNOW?

Stormwater runoff is #1 source of water pollution.

Pollutants from urbanized areas, if untreated, enter our waterways and endanger aquatic wildlife and vegetation.

 Stormwater pollution is classified in two ways.

Water pollution comes either from “point” or “nonpoint” sources. A point source is identifiable, such as a pipe or drain discharging a pollutant directly into a body of water. A nonpoint source is more difficult to define. It includes all the polluted stormwater within a certain geography, like a watershed, for example.

 There are many stormwater pollution culprits.

Significant stormwater pollutants include:

• Sediment
• Oil, grease, and toxic chemicals from motor vehicles
• Fertilizers and pesticides used on lawns, gardens, roadways, etc.
• Viruses and bacteria from pet waste and failing septic systems
• Litter and trash from motorists, pedestrians and businesses

There are over 7,250 MS4s in the country.

Population and location determine the regulated Municipal Separate Storm Sewer Systems, or MS4. An MS4 is defined as “a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains)” that is (1) designed or used for collecting or conveying stormwater and (2) is owned or operated by a city, county, or other governmental entity (including federal and state entities).8 The term “MS4” specifically excludes (1) combined sewers and (2) systems that are part of a publicly owned treatment works.  A large MS4 is any MS4 that is located in an incorporated place or county with a population of 250,000 or greater like Nashville or Knoxville. 

Only Rain Down the Storm Drain!