Sewage Sludge EFW

Sewage Sludge originates from the process of treatment of waste water; the physical-chemical processes sewage is subject to during treatment means the sludge tends to concentrate heavy metals and poorly biodegradable trace organic compounds, as well as potentially pathogenic organisms (viruses, bacteria etc) present in waste waters. However, it is rich in nutrients such as nitrogen and phosphorous and contains valuable organic matter that is useful when soils are depleted or subject to erosion. The organic matter and nutrients are the two main elements that makes this waste valuable as it can be spread on land as a fertiliser or an organic soil improver suitable.

The European directive the Urban Waste Water Treatment Directive 91/271/EEC sets an increase in the quantities of sewage sludge requiring disposal. Directive 86/278/EEC was adopted over 20 years ago with a view to encourage the application of sewage sludge in agriculture and to regulate its use in order to prevent harmful effects on soil, vegetation, animals and humans. The European Commission is currently assessing whether the current Directive should be reviewed .

There is a relatively small capacity for sewage sludge in UK Energy from Waste facilities, with only 3 operational facilities in 2016 accepting a total of 0.1 million tonnes of sewage sludge . This amount has decreased from 0.26 million tonnes in 2010. Cement kilns accept a small amount of sewage sludge in a pelletised form to be used as an Alternative Fuel.