There are about 5000-8000 inner city sewage treatment plants around the globe, which occupy very high value lands and are surrounded by offices and residential spaces.

Alkmaar WWTP is located in the city center. The large footprint of the current facility and the necessary exclusion zone prevent residential and business developments in the area.

Waterboard HHNK contracted Biopolus to create a concept design for a new greenhouse water treatment facility, which can replace the existing wastewater treatment plant. Biopolus and partners M.J.Oomen and VolkerWessels submitted a full package solution for the redevelopment of the entire site. The proposed facility presents a high quality urban infrastructure solution for a circular approach to wastewater treatment in Alkmaar. The treated water can be re-used in several ways such as irrigation, display, and process water for heating or cooling systems, or it can be safely released back into the environment. The footprint of the new facility is less than 10% of the current existing facility, is closed and odor-free, meaning it can be placed safely next to residential buildings.

Replacing an existing Inner City WWTP can free up valuable space for land value earnings of €25-30 million.