Describes a simple way to demonstrate the principles involved in a drinking water plant. This demonstration developed for a general public lecture can be used in chemistry and biology courses for an ecological and environmental emphasis. (HM)

Describes activities that demonstrate the effects of factors such as wind velocity, water temperature, convection currents, intensity of light, rate of photosynthesis, atmospheric pressure, humidity, numbers of decomposers, presence of oxidizable ions, and respiration by plants and animals on the dissolved oxygen concentration in water. (MA)