15/11/2019 - 14/11/2021


Proefstation voor de Groenteteelt (PSKW), coördinator, Aquafin, Vlaams Kenniscentrum Water (VLAKWA), 2 vollegrondsgroentetelers: Groentenhof Rudy Croket, Marc Van den Bosshe, 2 glasgroentetelers: Eco-Doc Bart Dockx,  Stannuco Steven van Nuffelen, Belorta, POM Antwerpen

AWAIR wants to establish a collaboration between horticulturists, Aquafin and researcher. The goal is to take the first steps in implementing treated effluent from sewage treatment plants (WWTPs) as an alternative water source. AWAIR thereby aims to provide a structural solution to an increasing frequency of water scarcity and minimizing natural water resources. For three horticultural clusters, varying in composition, the demand for irrigation water is matched with the availability of treated effluent at farm scale and plot level. It is crucial that the quality requirements are sufficiently high, Flemish and European legislation being the starting point. An area analysis and the results of the screening of treatment technologies will feed the feasibility studies for the 3 clusters. These studies will be worked out from the point of view of both Aquafin and the horticulturalists involved. For at least one cluster, the use of treated effluent will be worked out through a demo activity. The target audience will be reached through various communication channels.

AWAIR wants to highlight the opportunities of treated effluent for Flemish agriculture and horticulture. Moreover, the project builds strongly on the European network SuWaNu Europe, a European network that focuses on the reuse of treated wastewater in agriculture. The synergy of these projects will thus provide incentives to eliminate the backlog of implementation of treated effluent in Flanders.

Project Results:

The three area studies for Sint-Amands, Duffel and Hasselt can be downloaded from this project page. Measurement campaigns were set up at the three site WWTPs to gain more insight on water quality and water quantity. For both aspects, the supply from the WWTP is compared with the irrigation demand of agriculture in the region.

The area study in Sint-Amands includes a demonstration component, where different disinfection techniques were evaluated (with special focus on the reduction of E.coli). It also includes a first elaboration for the distribution network.

The area study in Duffel focuses on the reuse of WWTP effluent for greenhouse crops, with a focus on sodium accumulations in feed water during cultivation. This study looks at two scenarios for using WWTP effluent as a water source in greenhouse horticulture:

Reactive deployment of WWTP effluent. This is considered the reference scenario, where only RWZI effluent is added to the basin at the time of water shortages.
Continuous mixing of WWTP effluent with stormwater in the basins.

The area study in Hasselt looks at the reuse of WWTP effluent for outdoor crops in the area (especially asparagus)

It also looked at the financial aspect for developing such cases in practice. The feasibility analysis gives an overview of the various costs involved in setting up a case around structural water reuse. For each cost item, an estimate is made of its order of magnitude and importance in the overall costs. The uncertainties associated with different cost items are also described. The different cost items are:

1. Cost for additional treatment: this consists of an investment cost and an operational cost.
2. Cost for the transport network: this consists mainly of an investment cost and to a lesser extent an operational cost
3. Cost for permits and monitoring: this consists of a study cost at the beginning of the project and an operational cost.

An overview of different disinfection techniques that can be used for agricultural purposes was also prepared, including the advantages and disadvantages.

More information