water het blauwe goud

In Irricoli, the applicability of treated household wastewater as an alternative irrigation source for field vegetables is investigated, taking into account food safety and economic feasibility. 

Why this project? 

The availability of rain, surface or groundwater to irrigate crops during the growing season can no longer be taken for granted. During the dry spring and summer months of recent years (2017 - 2020), the use of surface water was restricted by issuing diversion/usage bans. This is to ensure the ecological carrying capacity of our streams and rivers. 

For the agricultural and horticultural sector, prolonged drought is therefore synonymous with great economic damage due to a reduction in yield and a reduction in the quality of the crops. The dry periods of 2017 to 2020 were therefore recognised as agricultural disasters. The sector therefore needs alternative sources of water to be used in times of drought and a possible alternative is treated household wastewater. Aquafin has this water source available in abundance; in sufficient quantities to meet the needs of Flemish agriculture. However, the use of this alternative is not without risk to food safety. Purified household wastewater still carries a microbial load. Moreover, Flanders lacks the knowledge and infrastructure to distribute treated household wastewater to agricultural areas in a sustainable way. 

Research approach and expected results

Irricoli is an agriculture (LA) project that aims to explore the potential of treated household wastewater as an alternative irrigation source for field vegetables. The focus is on food safety and economic feasibility. 

In 2023, an EU regulation comes into force that imposes strict requirements on the reuse of treated household wastewater for irrigation purposes. This includes the field of microbiology. By June 2023, the Flemish Environment Agency will also translate this legislation into the Flemish context. 

In order to substantiate this translation scientifically, the following steps are being taken within this project: 

  • Acquiring knowledge about the microbial water quality of treated household wastewater and investigating the effect of storage on water quality. Does storage encourage germ growth or does it provide 'natural' disinfection? 

  • Mapping how the microbiological contamination on green celery, spinach and cauliflower evolves over time after irrigation with treated household wastewater. 

  • Developing a tool that can estimate the cost of a piped water distribution system between a water provider and (a coalition of) farmers. 

  • Providing a financial and legal framework for the operation of a water distribution system through workshops. 

  • Spreading knowledge, through demonstration cases and workshops, throughout the wider agricultural and horticultural sector, water suppliers (e.g. food industry), engineering firms, but also with respect to governments & civil society for the translation to Flemish legislation. 

Target group

The project is primarily aimed at agricultural and horticultural companies with outdoor (vegetable) crops and potatoes. Project partners Boerenbond and Inagro are in close contact with growers in Flanders. 

The project results are also relevant to: 

  • Suppliers of treated waste water 

  • Service providers and subcontractors (e.g. engineering firms) 

  • Governments and civil society (e.g. translation of legislation, drafting of specifications...) 

  • Vegetable processing companies (represented by Vegebe and Flanders' FOOD) 

Project partners 

Flanders’ FOOD manages and coordinates the project. Responsibility for the execution: 

  • Inagro (Roeselare) under the direction of Dominique Huits (dominique.huits@inagro.be) and Tim De Cuypere (tim.de.cuypere@inagro.be).  

  • Boerenbond (Leuven) under the direction of Stijn Bossin (stijn.bossin@boerenbond.be) 

  • UGent - Campus Kortrijk (Kortrijk) - VEG-i-TEC research group led by Prof. Imca Sampers (Imca.Sampers@UGent.be) 

  • UGent - Campus Coupure (Ghent) - Research Group Hydro-Climate Extremes Lab under the supervision of Prof. Niko Verhoest (Niko.Verhoest@UGent.be) 

  • Vlakwa (Kortrijk) under the direction of Charlotte Boeckaert (cb@vlakwa.be) 

Flanders' FOOD logo
logo Boerenbond
Universiteit Gent
Vlakwa logo
Logo Vegebe


The Irricoli project started on 01/02/2022 and will run until 31/01/2024 (project duration 2 years). Until then, participation is possible. The results can be requested and accessed at the end of the project (for a fee). 


Ellen Martens
Ellen Martens
innovation manager