New sewage market: a resource which should not go to waste

11 Oct 2017 01:14 PM

Ofwat has taken the next steps in opening a new market that uses treated sewage to generate energy.

To make the market for this product work, Ofwat has set out guidelines and requirements on water companies to share common, consistent information about the waste – including about quantities and its moisture content – so those interested in buying it can make informed decisions on the value of the product they are buying

The treated sewage – known as bioresources – produces biogas, or green gas, which can be cleaned and injected into the gas grid or used to generate low-carbon electricity. When processed it can also be safely used in the agricultural sector as a fertiliser.

Ofwat is also introducing new requirements on water companies to publish information about their water resources, to encourage them to trade water between themselves and with third parties. This could mean water moving from where it is plentiful to where it is scarce and help respond to the challenges of population growth and climate change.

David Black, Ofwat Senior Director of Water 2020, said:

“We’re always looking for opportunities for customers to get better value. Sometimes that means thinking creatively about how we can get more from all parts of the water sector – even those that might make some of us feel a little squeamish.

“The idea of reusing waste to create low-carbon electricity works and can deliver environmental benefits and could also result in lower bills for customers. That’s why this idea is too good to leave in the dump.”

Notes to editors

  1. The process to treat bioresources, also known as sludge.
  • Sewage is taken away from homes and workplaces to treatment sites.
  • It is put into tanks where the heavier sewage sinks to the bottom and the lighter sewage is skimmed off and treated with bacteria which naturally breaks down the sewage.
  • The heavier sewage is mixed with the same bacteria and is then often passed to an enclosed ‘digestion’ tank which contains no oxygen. The conditions encourage particular bacteria which can break down the bioresources and stabilise it – destroying pathogens and reducing odour.
  • This process results in treated bioresources, which can be used as a fertiliser substitute by the agricultural sector, and biogas – or green gas – which can be used to generate electricity or injected into the gas grid.

Ofwat Press Office:

Tel: 0121 644 7642

Emailfintan.hastings@ofwat.gsi.gov.uk