Push the spray pump through the soil and into the gravel. Let one of the children operate the pump which will draw from the aquifer and to the surface. Continue pumping to lower the water table and the lake level. Precipitation can return to the previous levels. Discuss the effect of drought and rainfall, show the effect of groundwater contamination.
Colored sugar demonstrates nonpoint source pollution.
Mix 30 drops of food coloring per 80 grams of sugar. Spread the sugar over the surface of a plate and allow it to dry for one to two hours. Spread 40 grams of sugar over the sand. Sprinkle warm water on the sugar.