EXPERIMENT II- Non-Point Source Pollution

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Storm water flows over impervious (unable to penetrate) surfaces like driveways, sidewalks, streets, parking lots and roofs and is unable to percolate (filter or seep) into the ground. This unfiltered water reaches our neighborhood streams, ponds, lakes, bays, wetlands and oceans and can eventually make its way into our ground water. (Water beneath the earth's surface).

Stormwater runoff can collect many different types of pollution before it reaches a body of water, including debris, dirt and chemicals. The storm water collects these materials and flows directly into a body of water like a stream or lake. These water bodies may be used for swimming, fishing and may even provide some of us with drinking water! This experiment is designed to demonstrate what an average storm drain collects during a rainfall event and hose the water from storm drains can impact the water quality and aquatic environments of local streams, rivers, and bays.


  • “Waterway”
  • Aquarium
  • Rectangular Water Box
  • Watering Can
  • Spray Bottle
  • “Pollutants”
  • Green Food Coloring (pesticides/fertilizer)
  • Vegetable Oil (motor oil)
  • Soil/Sand/Pebbles (erosion)
  • Grass Clippings (or Shredded Paper) and Twigs
  • Cafeteria Waste and Trash


Fill the aquarium half-way with water and place it on an accessible area where it can be easily viewed. Cut a hole in the bottom of the box and place the box on top of the aquarium. The box represents the storm drain and the aquarium represents the waterway that the storm water mixes into after entering the storm drain. Leave the sides of the aquarium uncovered so that you can view its contents.


Try some of the removal methods. Which pollutants were easy to remove? Which were difficult to remove?

Source: Enviromental Protection Agency

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