Landfills are built like big swimming pool. They have special thick walls that are supposed to keep the garbage from leaking into groundwater. Still, oftentimes, over time the walls start cracking and garbage juice leaks out. You can demonstrate how this happens by creating your own miniature leaky landfill. Fill a jar with about an inch of water. Find a small plastic container, like a small yogurt container, that will sit in the mouth of the jar without falling in. Poke a little hole in the bottom of the container. Now start filling the landfill. What kinds of things end up in the garbage? Candy wrappers, old socks, dirty diapers, and much more. Using colored paper and markers, have the children draw tiny pictures of the different garbage items, or put in tiny bits of real trash. Just make sure you don’t it in too tight.
When the landfill is full, put a few drops of a dark-colored dye. This represents toxic substances such as paint and old oil that end up in the garbage. Now slowly pour in some water. This is the rain that falls on the garbage and the moisture that ends up in the landfill from old food. Watch what comes out of the hole. What happens to the water below the landfill? Did you know that many people’s drinking water comes from groundwater? What could happen if your drinking water had some garbage juice in it?