Thames Water is proposing to upgrade its sludge treatment facilities at Riverside Sewage Treatment Works, in Rainham – which will enable the plant to treat the solid waste left behind after the sewage treatment process and turn it into enough renewable energy to power the entire site.
The proposed upgrade will be located entirely within the existing sewage treatment works and will involve refurbishing existing digestion tanks and building new sludge thickening, de-watering and storage facilities. All measures are being taken to ensure the works will have no effect on odour. All process tanks and sludge storage areas will be covered or enclosed in buildings.
Sludge will be treated through anaerobic digestion, whereby solid waste is broken down in enclosed tanks in the absence of oxygen. The process generates renewable energy, in the form of biogas (methane) which can be used to run engines and turbines for heating and electricity. The process also leaves behind a nutrient-rich solid which can be used as fertiliser.
A planning application will be submitted in May 2008 and subject to approval, construction will begin in early 2009 with works due for completion by 2010.