The quality of drinking water has been gaining a great deal of attention lately, especially as water delivery infrastructure continues to age. Particles of various metals such as lead and copper, and other substances like radon and arsenic could be entering drinking water supplies. Spilled-on-the-ground hydrocarbon-based substances are also leaking into water supplies and pose a significant hazard. Being able to detect the presence of potentially harmful substances in the water supply is crucial to preventing serious injury, illness, death, or long-term problems for developing children and compromised members of society. This is a very practical problem and requires the thought and creativity of being able to envision squeezing the equivalent of a small chemical lab into the home or business and conducting water chemistry that can reliably and quickly detect the presence of certain bad substances. The author challenges for students to think about how to detect these substances.