Groundwater is an extremely valuable resource that many feel has been too long neglected and taken for granted. There is growing recognition in Illinois and throughout the United States that comprehensive groundwater protection measures are vital. Illinois embarked on a course in protecting groundwater resources with the passage of the Illinois Groundwater Protection Act in 1987. The Interagency Coordinating Committee on Groundwater brought 10 state agencies together to solve problems related to groundwater contamination. The Department of Energy and Natural Resources' primary responsibilities under the act involve research, monitoring, technical assistance, and education. This activity guide was produced in response to groundwater legislation in Illinois and is correlated with state learning goals in biology and physical sciences. Ten activities include the water cycle, how different soils affect water movement, porosity and permeability, water filtering, water monopoly, hazardous substances, waste disposal, and decision making. Appendices include background information, activity sheets, a glossary, a list of agency resources, additional curricular resources, and a conceptual framework. (CW)