Read C-3 Over 1.5 billion people do not have access to clean, safe water.1.5 billion people Almost 4 million people die each year from water related diseases.4 million people 98% of water related deaths occur in the developing world.98% of water related deaths A typical individual in the United States uses 500 litres of water each day.500 litres Over 1 billion people use less than 6 litres of water per day.6 litres Half the world’s schools do not have access to clean water, nor adequate sanitation. schools

Activity 30 Title: Can You Taste the Difference?

Read pg. C-4 Introduction Problem: Can you tell the difference between different kinds of bottled water and tap water? Hypothesis/Initial Thoughts:

Looking at the 3 water samples: Can you distinguish bottled spring water, tap water (from the municipal water supply), and store- bought distilled water on the basis of taste? Distilled water is produced by boiling it so that it forms a vapor. Minerals, called dissolved solids, and most other contaminants do not vaporize and are left behind. The water is cooled and turned back into liquid water Spring water is water obtained from an underground source that flows naturally to the earth’s surface, and is collected at the spring or through a borehole.

You have been given 3 different types of drinking water They are labeled A, B, and C 2 are bottled and one is from the tap This is a taste test, but what other senses may help you? Make your choices individually You will share your results with the class after everyone is finished Throw away your tasting cups when you are done with them---DO NOT throw away the labeled sampled cups

Data/Observation: Water testing Observations Water sample AppearanceSmellTaste Predicted sample identity A B C Leave 3 lines for A, B, and C

In your groups: Each student present your proposed identities of the samples and your reason for them Work together to come to an agreement on the identity of the three samples Record your group’s agreed-on choices and reasons in your science notebook

Group Water Samples Identities Sample Predicted Identity (include reason) Actual Identity (include reason) A B C Leave 4-5 lines for A, B, and C Choices: Distilled, Spring, or Tap Water

As a class: A spokesperson from each group will present your decision to the class (with reasons) As a class, you will attempt to reach a consensus on the identity of each sample

Follow-up: A is bottled spring water B is tap water C is bottled distilled water Discuss with your group, possible reasons for groups/individuals being successful or unsuccessful with the identifications of the samples

Trade-offs of drinking bottled water instead of tap water Do you prefer and buy bottled water at home? What are some of the reasons you might or might not buy bottled water? –Cost –Taste –Known and unknown health trade-offs

What are the limitations to taste tests as a method for identifying the water? –Taste is based on perception What else would you want to know before deciding which kind of water to drink? –There may be substances in the water at levels too low for people to taste –Can’t always taste contaminants

Millions of Americans drink bottled water instead of their local tap water Why do people drink bottled water? –Health –Taste –Convenience Bottled water may be no safer– maybe even less safe than tap Current industry and government estimates suggest that approximately 25-40% of bottled water comes from tap water, sometimes with additional treatment, sometimes not

Bottled water is considered a food product and is regulated by the federal Food and Drug Administration (FDA) Tap water is a natural resource overseen by the EPA, which sets slightly different standards The FDA rule does not apply to 60-70% of the bottled water sold in America because they do not apply to water sold in the state where it is bottled.

Tap water must be tested for harmful bacteria more than 100 times per month, while bottled water plants are required to test only once a week. The standards governing nearly 200 inorganic and organic chemicals are less strict for bottled water In general, states have fewer staff assigned to routinely test bottled water than tap water—in some cases only one or two people for the entire state, while hundreds of federal and state workers oversee the safety of tap water. Do Analysis 1-3