The rise in the number of people living in cities - predicted to reach 80 % by 2020 - coupled with climate change is straining Europe's water supplies. An EU-funded project has demonstrated innovative technologies and approaches to tackle water scarcity.

According to the European Commission, assuring the supply of water to Europe’s cities will be a tough challenge as urban populations rise, demand grows and climate change affects supply. The EU-funded DESSIN project has demonstrated innovative solutions for ensuring Europe has adequate water quality and supply to meet its needs.

At five demonstration sites in cities in Germany, Norway, the Netherlands, Greece and Spain, the project tested integrated technological, monitoring, modelling and management approaches. The demonstrations aim to encourage Europe’s water sector to become more resource-efficient and competitive through innovation.

The project also developed a framework for assessing the changes to water bodies brought about by its solutions, as well as the economic, environmental and social value these provide – known as ‘ecosystem services’ (ESS).

The project’s ESS toolkit allows decision-makers to assess the value of provision services, (e.g. food and water), supporting services (e.g. pollination and climate regulation) and cultural services (e.g. aesthetic value and recreation) when proposing and comparing water supply solutions.

Project coordinator David Schwesig of IWW Water Centre in Germany commented:

 “By adopting this approach, we are able to demonstrate how innovative solutions integrated in the water cycle can increase the value of the services provided by freshwater ecosystems. This can help drive their market uptake.”

Sparking innovation and competitiveness

Each of the following cities selected for the demonstrations represent some of the world’s major water scarcity challenges.

• Emscher in Germany
• Hoffselva in Norway’s Oslo area
• Westland region in the Netherlands
• Athens in Greece
• Llobregat in Spain’s Barcelona area.

“This approach will support innovation and competitiveness in water management by enabling a more informed selection of the most promising solutions, regarding their impact on the water body and their economic implications,”  Schwesig continued.

DESSIN demonstrations include:

• a cross-flow ‘lamella settler’ separator, a type of water filtration technology, to treat sewer overflows into the Emscher river tributaries and thus reduce pollution on a major river;
• a high-rate filtration system with specially designed filter media;
• an automated real-time online control system to reduce the combined sewer overflow from all of a city’s water treatment facilities to control the amount of pollution entering a water system;
• the integration of local treatment units by way of monitoring and data communication systems;
• the use of distributed re-use technologies, both modular and mobile, with a focus on sewer mining technologies for urban green irrigation in water-scarce areas;
• a hybrid aquifer storage and recovery system, allowing brackish aquifers to store clean water for re-use by the horticulture industry.

‘Sewer mining' system can recycle water even in dense urban areas

In Athens, the project focused on water re-use for non-drinkable uses like watering city parks and urban agriculture. Water re-use in cities is currently rare, and the recycling facilities that do exist for are usually installed next to large sewage treatment plants that can be far away from where re-used water is needed.

DESSIN aims to help turn the current situation around by creating water recycling technologies that can be installed even in the heart of dense urban areas.

The project has developed a compact decentralised water re-use system that can be installed in an urban neighbourhood. Called ‘sewer mining’, the system can provide recycled water for numerous uses, including watering nearby parks and hydroponic plant growing systems.

“The idea is to provide reclaimed water by extracting wastewater from the sewage system, treating it at the point of demand, and, in some cases, returning treatment residuals back to the sewer system,” said Christos Makropoulos, coordinator of the pilot sewer miner in Athens, Greece, and a professor at the National Technical University of Athens.

“Sewer mining can provide re-used water on-demand using compact technology tailored to end-user needs; and units can even be placed underground,” he added.

The pilot consists of a compact sewage treatment unit with a membrane bioreactor and reverse osmosis technology, as well as information communication technology that allows it to be operated remotely and monitored and managed in real time.

The system – which has been up and successfully running for over a year on the premises of the Athens Water Supply and Sewerage Company (EYDAP) – is being used for the irrigation of a small park.

Technology particularly suited to Southern Europe

The pilot project has since attracted the attention of Greek technology companies keen to develop more urban sewage treatment systems, and the City of Athens itself, which is looking at opportunities to use the technology to irrigate other urban green spaces.

“Our technology is particularly suited to the more water-scarce regions of Europe in the South and the Mediterranean, where re-used water could be used to irrigate urban green spaces, improving the quality of life for urban dwellers during the hot summer months,” Makropoulos continued.

The technology also has benefits for the local economy since SMEs using the technology can sell irrigation services to city municipalities. In addition, water companies can benefit from selling untreated sewage to these SME service providers.

DESSIN’s technology has already been recognised: EYDAP participated in the European Business Awards for the Environment (EBAE), submitting the DESSIN sewer mining pilot as its green technology of the year; the company was awarded two prizes: the Products & Services Award and the Business & Biodiversity Award.

Germany acted as Coordinator of the €9million-plus EU-funded project which started in January 2014 and is due to conclude in December 2017.

Watch three short videos on the Waterbriefing Watch Channel which explain innovative technical solutions at Emscher demonstration site where two innovative technologies have been – or are still being – pilot-tested.

Video 1  of looks at the Emscher area, its challenges and its ongoing restoration process

Video 2 -  a cross-flow lamella settler to improve combined sewage water treatment inside storage facilities in the sewer network, developed by DESSIN-partner UFT and

Video 3 - the ADESBA real-time-control system to enhance storage of combined sewage inside the sewer network, developed by DESSIN-partner SEGNO.

Click here to visit the project website