Also tell students that they may not select one or more of the cups if they wish. After tasting the water in the cups, ask students if they would enjoy drinking several cupfuls of the water from one or more of the taste testing cups. Emphasize the point that fresh water is a problem to find in many regions of the earth. Brainstorm ways in which our modern way of life has increased water use since prehistoric or pioneer times. Although huge water reservoirs formed behind dams provide a water supply, this alternative is not without problems.
Wells are common water sources for many villages in the Middle East and Africa.
Canadian water drilling companies have been active in the African Sahara for decades. Note the recently discovered horror of well water in areas of Bangledesh and India where arsenic poisoning has affected as much as 200,000 people or more. Wells have caused the water table to drop, leaving rock and soil below the earth's surface that were once covered in water to become exposed to the air. This has caused the release of arsenic in the earth to be released into the remaining underground water supplies and to be pumped to the surface for people's use. The arsenic poisoning has been detected in the human body only after a ten year of drinking the contaminated water, and in many cases the poisoning process in irreversible, eventually causing death.