Water's running out - is sewage the solution?

Fred Pearce

22 August 2013

In a world of droughts, climate change and rising population, is sewage the answer to stop our taps running dry? Guest blogger, journalist and author Fred Pearce, thinks so - if we can only get over the yuck factor.

Sewage contains two things we badly need: organic nutrients such as nitrogen, and water. Cities once took advantage of this, operating "sewage farms" that used faeces as fertiliser.

But modern cities prefer to build huge sewage treatment works - partially cleaning up our effluent before pouring it into rivers and on to the ocean. The idea has been to discharge sewage as fast, and as far away, as possible. The result is that we are deprived of both the water and the nutrients.

There are growing calls to turn the tide, and find ways to safely recycle these vital resources.

Both Israel and Mexico use treated sewage for irrigation. Many farmers in poor, drought-prone nations fight to get access to the raw contents of sewage pipes.

In Pakistan, a quarter of the country's vegetables are irrigated and fertilised thanks to raw sewage. In Bangalore in India, tankers that empty septic tanks earn extra cash by selling the contents to local farmers.

Can we drink it? Properly cleaned up, yes we can, as hi-tech Singapore is showing. And it is not alone.

California's Orange County pours treated sewage into rocks that filter it sufficiently for it to be pumped up for tap water.

There are health issues, of course. This has to be done right. But the days when cities use their water only once could - and should - be coming to an end.

Read Fred Pearce's article about how Singapore is recycling sewage and join the discussion about how we can make our cities sustainable.

The following guidance is primarily intended for children, young people and vulnerable adults: We want everyone to feel safe and secure when using our online public spaces. If someone does something you find upsetting, please mention this to an adult you trust or email us at [email protected]

Comments powered by Disqus