Decentralized water purification systems

For households and other buildings that are not connected to the municipal sewer network, decentralized water purification systems can be used to treat the effluent of wastewater before discharge. NBS such as constructed wetlands can be a great alternative for the treatment of domestic wastewater, contributing to the improved water quality of the receiving water bodies.

Constructed wetlands are installed in several Provincial Domains in West-Flanders to treat domestic wastewater coming from (public) toilets, taverns and restaurants. Other examples of individual treatment systems for private houses (often referred in Flanders as IBAs – Individuele Behandelingsinstallatie voor Afvalwater – Individual wastewater treatment system) and small villages for up to 250 P.E. (also called KWZIs – Kleinschalige waterzuiveringsinstallatie – Small-scale water treatment system) can also be found in West-Flanders.

Type of landscape : Rural Landscape

Ecosystem : Small household district

Reeds are often planted within constructed wetlands. These plants filter nutrients out of the water. (source: Province of West-Flanders)

Water quality parameters of the influent and effluent of wastewater will be monitored (e.g., pH, conductivity, oxygen level, floating substances, ammonium, nitrite, nitrate, total N, Kjeldahl-N, orthophosphate, total P, BOD, COD). The installation and maintenance of these systems can be funded by local authorities, Province of West-Flanders, VMM and/or within the projects of Water-Land-Schap.

Key concepts

Decentralized water purification systems, such as helophyte filters, constructed wetland, and IBAs (Individuele Behandeling voor Afvalwater, individual systems for treatment of domestic wastewater as known in Flanders) can provide a great alternative for treatment of domestic wastewater in small household districts located in remote locations that are not connected to the main sewer networks. These systems are targeted to remove suspended solids, nutrients and other components from water through natural processes, such as settling and filtration, adsorption into substrate media, as biological degradation.

Specific NbS tailored for the region

Decentralized water purification systems for (peri-)urban and rural landscapes help lower the nutrient concentrations that flows into surface water in households where no other means of wastewater treatment is provided. These plant-based systems can vary from very small systems that purify water of 1 household, to larger purification systems where a few dozens or even more households (or restaurants, businesses, …) are connected to. Some of these systems are present in the provincial domains of West-Flanders, others are present in the gardens of private houses.

Environmental Challenges

Water pollution, water quality, loss of biodiversity

Policy Support

Some systems are funded or subsidised by the government and/or local authorities, others are partly subsidised and partly paid by the inhabitants (IBAs).

Expected impact of NBRACER

NBRACER will offer support to further develop the existing knowledge on this topic with new insights provided through the project’s international framework. The project can help mainstream the implementation and the replication of the NBS and contributes to the active engagement necessary from regions to offer an integrated support system to combat the current and future climate challenges facing our landscapes.