The Cooks River in Sydney has been variously described as an open sewer, the River of Death, and one of Australia's most polluted rivers. Yet there are plans - possibly rather hopeful plans - to bring swimming back to the river. There are numerous such rivers in cities around the world, so how realistic is the idea that you could bring swimming back to polluted city rivers? Could ex-industrial rivers join the oceans (and dams) of Australia as recreational swimming spots?

Professor Stuart Khan from the School of Civil and Environmental Engineering at UNSW studies sustainable urban water management, and has studied chemical composition of the Cooks River, and how the pollutants got there. He thinks that, whilst it may be a long way off, there are precedents around the world for bringing back swimming to polluted rivers.

You can read more on efforts to remediate the Cooks River at the Cooks River Valley Association.

Songs in this episode - all licensed under a Creative Commons License

• Funk City - Reatch