A hazardous mix of waste is flushed into the sewer every day. The billions of litres of water - combined with unknown quantities of chemicals, solvents, heavy metals, human waste and food - where does it all go? And what does it do to us?

From ancient times, countries have chosen the sewer to get rid of household and industrial waste, yet the contaminants we flush resurface in our food chain. Fish swim through waste water dumped into rivers, while sewage sludge is spread on farmland as fertilizer.

Filmed in Italy, India, Sweden, the United States and Canada, this bold documentary questions whether the sewer is actually compounding our waste problems. While scientists warn of links between sewage practices and potential health risks, activists, engineers and concerned citizens challenge our fundamental attitudes to waste. Does our need to dispose of waste take precedence over public safety? What are the alternatives?