Our history

Since the start in 1989, Colsen has undergone significant development. We evolved from a one-person consultancy to an organization with over 60 employees, where innovation and global partnerships are key pillars. Nevertheless, at our core, we have remained the same: a family business with expertise in environmental technology who strives to create a positive impact on the environment.


1990 opening kantoor

After working as a technologist in various water boards, Joop Colsen establishes his own environmental engineering consultancy. Fueled by a passion for knowledge and innovation for water treatment plants, the organization 'Colsen' begins its journey from home.


Kantoor oud

The team is growing rapidly. Starting with an environmental coordinator, an average of one person is added each year. Colsen outgrows the home setting. After relocating to temporary units, the office in Hulst is built in '95.

Early ‘90's

Pilot 2002

The beginning of the innovation agenda. In collaboration with knowledge institutions, the service transitions from demand-driven advice to developing and offering technology and process solutions.

Late ‘90's

Jurgen Joop China

Many existing clients become multinational corporations and operate globally. Colsen grows alongside these clients, and the realization quickly sets in that there are significant international opportunities for our technologies.

2005 - 2012

Bestuursleden Colsen voor hoofdgebouw

Boris Colsen and Jurgen Brekelmans join the company. Initially as project leaders, but under the guidance of Joop Colsen, they gradually take on more managerial responsibilities. From 2009 onwards, the three of them form the executive team until Joop formally steps out after three years.

2014 - 2018

colsen aquest ahidra

Research indicates that our technology is highly applicable in South Africa. The establishment in South Africa, as Aquest, crosses our path in 2014. In 2018, we also add Ahidra in Spain to the Colsen Group, providing convenient access to Latin America. From that moment the Colsen group is formed by Colsen (the Netherlands), Aquest Colsen (South-Africa) and Ahidra Colsen (Spain).



As Colsen, we actively seek partnerships abroad, wherein we provide our expertise, and local partners undertake the project construction. Mergers and acquisitions or autonomous growth are not goals in themselves; we aim for collaboration.