Project Facts

  • Client
    Vitens N.V.
  • Industry
    Drinking water
  • Application
    Softening as part of entire water treatment plant
  • Location
    Bunnik, The Netherlands
  • Operation start
    2014
  • Capacity
    12,000 m3/day
  • Pre-treatment
    None
  • Post-treatment
    Sand filtration

Dutch largest water supply company Vitens, decided to expand her existing water treatment plant at Bunnik with a softening stage, to achieve a soft water quality. About 75.000 citizens will receive now softened water. The total hardness of the drinking water is decreased from 14 °DH to a value of about 6,5 - 7,8 °DH.

Softened water helps citizens

The advantage of softened water is reducing and avoiding lime scaling on sanitary and heating elements. Devices like as washing machines and kettles will have a longer life-span. Finally, soap foams better with softened water, resulting in, for instance, less shampoo, detergent or salt consumption. The citizen of Vitens value soft water from the tap, due to a positive sustainable and economical enhancement to their lives.

The project 

Crystalactor in Bunnik, VitensThe project contains the following major elements:

  • Enlarging the capacity of Bunnik to the required permit capacity of 3,5 Mm³/year.
  • Realisation of the softening plant and CO2 dosing
  • Installation of the storage reservoir of 3.000 m³ to ensuring a constant water supply to the cities Houten and Bunnik;
  • Realisation of back-wash treatment facility.

Royal HaskoningDHV assisted Vitens within the preparation phase of the project by carrying out the following activities:

  • Terms of Reference
  • Preliminary and detailed design
  • Tendering and contract documents.

The wave

The design of the new building was made by Royal HaskoningDHV. Special attention has been made to the architecture of the production facility. The new building connects with the existing building by the "horizontal water wave".

Vitens N.L. Bunnik

In this building, a new softening installation is constructed, consisting of three pellet softening reactors, sand bunker, pellet silo and a chemical plant. In the reactors, calcium and magnesium precipitate to a sand seeding material, whereby pellets, small lime crystals, are formed. These pellets are sold and reused in the iron, glass and concrete industry contributing to a decrease of operational expenditures.

Crystalactor in Bunnik - Vitens