What happens to our sewage?
Two children meet the animated character Curious Cat, who asks them if they would like to find out what happens to our sewage once it leaves our homes. The children meet an expert who takes them underground to see a sewer. They see the raw sewage travelling through the sewer tunnels before going to explore them. Next, the children visit a sewage treatment plant where they meet a second expert who takes them on a tour that shows them how the raw sewage comes into the treatment plant, how it is cleaned and then sent back into the river. They see solid waste in the sewage being taken out before being told how the microscopic bits of sewage still remaining are eaten by a variety of micro-organisms that use a filter bed made of special rocks. Throughout the tour, the expert takes water samples so the children can compare the dirty sewage that comes in with the clean water that goes out at the end of the process.