Sewage Sludge

Sewage Sludge originates from the of treatment of waste water. Due to the physical-chemical processes that sewage is subject to during its treatment (including Anaerobic Digestion), the sludge tends to concentrate heavy metals and poorly biodegradable trace organic compounds, as well as potentially pathogenic organisms (viruses, bacteria etc) which can be present in waste waters.

However, Sewage Sludge 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.

There is a limited amount of Sewage Sludge EFW in the UK. The most recently reported UK Waste Tonnage indicates that around 1.2 million tonnes of waste were produced by the Water and Sewage sector.