A demonstration using a model of a watershed was used to show how water borne sediments and other wastes are a threat to water quality. It was shown how wetlands and and other vegetated areas help to control flooding and clean the water through absorption and filtration.

This topic was combined into one session with another topic: Recipe for Trouble and Water Under Foot . Using models students learned about the transportation of pollutants into ground and surface water. Different types of soils were discussed. Recharge and infiltration were demonstrated.