Learners design their own experiment to investigate how pollution diffuses through ground material. This model for leaking underground storage tanks helps learners connect their learning to ecological environments. Includes extensions on page 11. The first extension frames an experiment using observations from the activity, and the learners are also challenged to create a better tank. Part of the 21-activity guide published by OMSI, No Hassle Messy Science with a Wow. All activities in this guide use household materials and all lesson plans include preparation directions, demonstrations, procedure sheets, cross-curricular connections, and scientific explanation of content.