The executive board approved the plan for the new water treatment plant in Wilp, in the municipality of Voorst, at the end of last year. “It is a unique concept,” says Bert van Vreeswijk of the water authority. “Last year, together with engineering consultants Witteveen+Bos, Vallei en Veluwe looked at opportunities and ways to improve this new treatment concept. I am happy with this outcome: an ‘all-in-one’, circular water treatment plant.” 
Circular working in 2050  
With the new treatment plant, which will eventually replace part of the wastewater treatment system in Terwolde, the water authority is taking an important step towards achieving complete circular working by 2050. An example is collecting and processing waste and rainwater separately, so that rainwater will no longer pass through the treatment system. Some of the water treated at the plant can be used to replenish the Twellose stream, so that it will once again contain good quality water. The new plant will extract at least 75% more nitrogen and phosphate from the polluted water and 80% than a regular treatment plant. The aim is also to extract 80% of medical waste, to reduce the amount of residue sediment by 90% and to reduce the use of chemicals by 90%.
Pilot project and cooperation
With the new treatment plant, which will eventually replace part of the wastewater treatment system in Terwolde, the water authority is taken an important step towards achieving complete circular working by 2050. An example is collecting and processing waste and rainwater separately, so that rainwater will no longer pass through the treatment system. Some of the water treated at the plant can be used to replenish the Twellose stream, so that it will once again contain good quality water. The new plant will extract at least 75% more nitrogen and phosphate from the polluted water and 80% than a regular treatment plant. The aim is also to extract 80% of medical waste, to reduce the amount of residue sediment by 90% and to reduce the use of chemicals by 90%.
The Vallei en Veluwe water authority is working together on this project with the municipality of Voorst, the province of Gelderland and the Ministry of Infrastructure and Water Management. They are also working with the companies Attero and Schoneveld Breeding and with knowledge partners Aquaminerals, STOWA and Wageningen University & Research (WUR).
Witteveen+Bos and Royal HaskoningDHV are first going to work on the project as a construction team on a pilot to test whether the newly developed concept is feasible in practice. They are also going to make a start on designing the new installations. In addition, the water authority will be looking for a suitable location close to Schoneveld Breeding and Attero on the Sluinerweg in Wilp.
For further information see www.vallei-veluwe.nl and www.witteveenbos.com