The focus of the lesson for ‘94 on sewers was narrowly chemical. Water in its journey to a sewer picks up debris and living organisms in addition to suspensions, particulates and chemicals in true solution. Water could be collected from a variety of sewers. Students could guess its contents using maps that indicated where the water came from and devise mechanical (physical), biological and chemical means to separate and identify the contents of water. ‘ChemTech’ kits can be ordered that are designed for the purpose of testing water purity. The experiments could then be developed to teach aspects of analytical chemistry.
The experiment encourages the critical art of sleuthing for answers. It naturally uses an interdisciplinary approach. Science is then experienced not as a set of narrow disciplines in self-contained boxes but as a way of going about solvingproblems and presenting evidence to justify ideas.