Grade Level: 5th - 8th; Type: Earth Science
- What are the differences in composition between tap, bottled, and filtered water?
- Are these differences significant? Can the differing levels be healthier or more harmful?
- What are the costs?
Bottled water has become popular as seen in the wide selections of brands available in stores and bottled water vending machines. Some bottled waters claim to promote health, are "expertly designed", and help you lose weight. There are a number of processes to purify water such as distillation, reverse osmosis, evaporation, and filtration. In this experiment we will determine the advantages, or disadvantages of these designer waters and compare it to our local tap water.
- 2 brands of bottled water
- tap water
- Water filtration system such as a Pur or Brita filter. Filtered water bottles are available for $10 at superstores or online.
- Water test kit
- Gather all your water samples. Choose at least 2 bottled waters, your home tap water, and filtered water (either store bought or through an at home filtration system).
- Follow the directions on your water test kit. These will differ from kit to kit.
- Test each water sample for the following: Pesticides, bacteria, chlorine, lead, pH, hardness, and nitrates.
- Record your data on a chart similar to the one below:
- Determine which is the healthiest water by comparing levels of contaminants or additives. You can create a graph of your data to visualize differences in concentrations.
Terms/Concepts: Distillation; Reverse osmosis; Evaporation; Aquifer; What are the drinking water standards?; What tests are performed on drinking water? Are these tests universal for all sources, such as tap and bottled waters?