Nature's water filter/background

This is a place holder for more in depth information.

Thesis
This lesson plan will demonstrate how the limited quantity of fresh water on earth is purified by the environment.

Description
We will be creating a lesson plan for 6th and 7th graders explaining how water naturally filtered by the environment. We will have the children construct a water filter to purify pond water using a 2-liter soda® bottle, and different materials such as pebbles, kitty litter, clay, moss, cheese cloth, charcoal, potting soil, marbles, sand, and gravel. This experiment will be a contest to see which student receives the purest water. Students will also be asked to form a clear hypothesis about the materials they used for their filter and the order they used to layer these materials in the filter. They will also be asked to measure out a certain volume of water to pour into their filter and use a stop watch to record the amount of time it took for the water to filter through.

Initial Citations
Basic Ground Water Hydrology [Internet]. GWAC [cited 2009 Jan. 21] 7 p. Available from http://www.issaquah.org/COMORG/gwac/Hydro.htm

Byron, N. 2007. Water Resources: An Introduction. Issues. 79: 4-8.

Ecosystem Services-Water Purification [Internet] Science Net Links; 2002 June [cited 2009 Jan. 21]. 4 p. Available from http://www.sciencenetlinks.com/lessons.cfm?DocID=275

Linden, K.G., Hazen, R. Water Treatment [Internet]. Access Science @ McGraw-Hill; 2008 [cited 2009 Jan. 22]. 5 p. Available from http://www.accessscience.com/content.aspx?id=739400

Neisat, M., Vilar, M. 2000. How Water Runs. Science World. 14: 18-21.

Pons, L. 2006. Clean Waters and Agriculture: We Can Have It Both Ways. Agricultural Research. 54:12-15.

Water Filter Experiment [Internet] Aqua Ducks Water World [cited 2009 Jan. 21] 1 p. Available from http://library.thinkquest.org/04apr/00222/filter.htm