Introduction
Many chemicals dissolve in water because it is an excellent solvent. Once dissolved, these chemicals are not visible to the human eye. Therefore, many chemicals might be present in water without providing any visible evidence. Additionally, some substances can be present in very low concentrations and still cause health concerns. For these reasons, drinking water needs to be tested for contamination. A variety of chemical tests are used to detect water contamination. Most of the tests are specific for a particular contaminant. The test reagents react with the specific contaminant to cause a color change. The color change indicates that a particular contaminant is present in sufficient quantities for the reaction to occur.
Discovering that their well water is contaminated with C. jejuni made the Williams family curious as to what else is present in their water. In this activity, you will investigate various drinking water contaminants and their effect on human health. You will perform a series of tests to determine what contaminants, if any, are present in the Williams’ well water as well as in the local water sample that you collected.
Equipment
Computer with Internet access
Laboratory journal
Activity 4.1.3 Student Resource Sheet * Lab-Aids Qualitative Introduction to Water Pollution Kit 19 * Local water sample * Wiliams’ well water sample * Safety glasses * Lab apron
Latex or nitrile gloves Procedure
Take notes in your laboratory journal as your teacher presents the Water Contamination presentation. Alternatively, your teacher may have you go through the presentation independently.
Make the following data table in your laboratory journal. Leave plenty of writing space in the Effects on Human Health columns. | Short Tem Effects on Human Health | Long Term Effects on Human Health | Contaminant Present in Local Water Sample (Present or Not Present) | Contaminant Present in