Sewage is now discharged into our rivers and seas on a regular basis. It's joined by agricultural pollution and a host of microplastics. In this special debate programme, Tom Heap asks what's gone wrong with our water system. How did we get into this situation, what will it cost to put it right, and how can we go about sorting out the mess we seem to be in? Tom is joined by a panel of experts to discuss the history, the finances and the future of cleaning up our waterways. Producer: Emma Campbell