The average consumption for EU member countries is 128 litres per inhabitant per day and most of it turns into wastewater.

The status of wastewater has improved tremendously over the past few years. This is mainly because water and wastewater treatment plants have become more efficient and innovative, enhancing their processes and thus maximising output use by recovering energy and nutrients, recuperating organic matter and producing clean, reusable water – sometimes even drinkable – instead of simply regarding it as waste. Energy recovery from wastewater can be a good business case – for example, when it reduces the cost of sludge disposal. 

As technologies improve, more clients are becoming aware of the resources in their wastewater and recognising the potential not only to optimise their processes but also to contribute to achieving a sustainable society. Take, the example being set by Denmark’s largest wastewater treatment company which has focused on recovering gas and energy from wastewater. It is now selling two and a half times more energy units than it consumes. The plant also produces around 20 % of the gas used in Copenhagen’s 'city-gas' system. The goal is to reach 60 % in 2020 and hence support the city's overall goal of becoming CO2 neutral in 2025.

More than 100 000 tonnes of organic waste each year can now be combined with the waste-activated sludge from the local municipality and processed to produce 5.4 megawatts of combined heat and power and over 6 000 tonnes of usable fertiliser instead of being disposed of in local landfills. The overall design of the facility incorporates a mixture of both well-established and novel solutions to maximise recovery of the wastewater resources.