Decentralised sewage treatment plants


The decentralised sewage treatment plant project resulted in the preparation of a comprehensive report prepared by an external consultant that reflects the state of wastewater treatment in the EU in the middle of the first decade of the new millennium.


A proper treatment of domestic sewage is highly relevant for the good environmental quality of receiving surface waters. According to EU’s Urban Waste Water Directive (Council Directive 91/271/EEC ) biological treatment of all discharges from agglomerations of > 2,000 population equivalents is required. To protect the environmental quality of the freshwater environment , a sizeable fraction of the European population will be required to implement its own decentralized waste water treatment. Such small scale wastewater treatment plants [WWTPs] are decentralised and likely to complement existing large facilities throughout the EU.

Decentralised sewage WWTPs are relevant for CEE countries and other EU member states, where connection to WWTPs is currently low or the treatment of wastewater not well advanced. At least 100 million people are potentially covered by such facilities, tailored towards the size of their community needs. These facilities are likely to cover a range of different technologies. Knowledge about their effectiveness in removing surfactants has filled a significant gap in our understanding. This work will help industry mitigate future risk assessment as required under the relevant legislation.


Within this project several tables with information on the performance of small scale wastewater treatment technologies were generated including information on performance parameters and nomenclature as well as reed bed technology.