In a pilot project conducted in the city of Kalmar in south-eastern Sweden, treated wastewater effluent originating from a municipal wastewater treatment plant is disinfected by further filtration and UV light treatment and then used to water green spaces. The process: treated wastewater that has been discharged back into natural waters is pumped from the wastewater treatment plant’s discharge channel into a mobile container. There, filtration and UV light are used to reduce the content of microorganisms. A mobile tanker then transports the water to the green areas, which are irrigated directly from the tanker using a hose system.
In terms of quality, the water meets the criteria of water class A and is also authorised under EU Regulation 2020/741 for the irrigation of edible plants in agriculture. From a purely technical point of view, this high quality would not even be necessary for watering green spaces. However, it offers the additional advantage of promoting acceptance of the new method among the personnel involved.
- Location: Kalmar (Sweden)
- Water source: Treated wastewater from wastewater treatment plant
- Type of treatment: Disinfection by filtration and treatment with UV light
- Target water quality: Water class A (EU Regulation 2020/741)
- Utilisation: Irrigation of green spaces
- Return to natural cycle: Infiltration
- Responsible: Kalmar Municipality
- Open for visitors: August 2024