Giving Compass' Take:

• Tim Radford argues that the wastewater that flows through the world’s sewers has value that could be recovered.

• How can donors help support these efforts and develop this new energy source?

• Here's how federal policy could help water and wastewater utilities. 

Canadian scientists have identified a new source of energy, wealth and nourishment being lost every day in every city, town and municipality on the planet: a great river of wastewater.

What swirls down the kitchen and bathroom plugholes in every home, cascades into the town drains and flushes the city sewers contains enough latent energy to power almost 160 million households.

The flow of wasted water is big enough to irrigate up to an area equal to one-fifth of all the farmland in the European Union. And the nitrogen, phosphorus and potassium that sluices down the world’s drains would be enough to meet almost one-eighth of the world’s fertiliser demand, and notionally generate a revenue stream of more than $13 bn a year.

In effect, the researchers argue, humans are every day flushing good money down the toilet. And this stream of lost income could only keep growing. Right now, according to a new study in the UN journal Natural Resources Forum, the world’s wastewater discharges add up to 380 billion cubic metres a year.

This is five times the volume of the water tumbling over Niagara Falls on the US-Canadian border. It is equivalent to the entire flow of the Ganges through the Indian subcontinent: it could fill Africa’s Lake Victoria in seven years, and Switzerland’s Lake Geneva in three months.

Read the full article about wastewater by Tim Radford at Eco-Business.