Sludge and biogas
Treating wastewater is our main task. But we also exploit the nutrients and energy contained in the wastewater, and produce sludge and biogas that are recycled to the community.
Sludge used as fertilizer
Our sludge is certified annually in accordance with the Swedish Water & Wastewater Association’s (our industry organisation) certification system REVAQ, and can be used on arable land as an alternative to mineral fertilizers. The sludge is rich in nutrients, among them phosphorus and nitrogen. It undergoes continuous quality control. All of the nutrients is returned to the ecological cycle and used on arable land.
Biogas becomes fuel for buses
We produce the biogas in the Käppala plant’s digesters. We upgrade the biogas to vehicle fuel quality in our upgrading facility. The gas is used as an environmentally friendly fuel for public transport buses. In this way, we help reduce the emissions of fossil carbon dioxide in the Stockholm region.
The Käppala Association is environmentally certified in accordance with ISO 14001. Our own laboratory is accredited by SWEDAC in accordance with ISO 17025.