Our most precious rivers are facing ecological collapse for two main reasons: sewage and farming. Water companies routinely pump raw excrement and other pollutants straight into them. As livestock are concentrated into industrial units, such as chicken farms in the Wye Valley, they produce too much dung for the land to absorb. How do we fight the tide of filth and bring our lovely rivers back to life? George Monbiot is a journalist and environmental activist. Feargal Sharkey, former frontman of The Undertones is a vocal campaigner for clean rivers. Chaired by Nicola Cutcher, freelance journalist, writer and documentary filmmaker.