Recycling treated wastewater in public buildings

This feasibility study from the Kalmar region in Sweden is exploring how recycled wastewater can be reused in public buildings. The point of reference is a hospital in which a dual pipework system has already been installed.

The study is investigating whether this water can later be supplied by a new water treatment plant currently under construction in Kalmar. However, the use of greywater (i.e. moderately contaminated wastewater from the building itself, e.g. shower water) and stormwater is also being considered. In addition to the question of technical feasibility, the economic viability will also be analysed. There are also legal challenges: differentiated pricing for water of different qualities – and therefore an incentive to use it – is not yet possible in Sweden.

• Location: Kalmar (Sweden)
• Water source: Treated wastewater from new treatment plant, greywater from public buildings, stormwater
• Type of treatment: Necessity is being examined in the scope of the study
• Target water quality: To be determined in the study
• Utilisation: E.g. toilet flushing
• Return to natural cycle: Discharge into sewage system
• Responsible: Region Kalmar County
• Available: September 2025