The construction project for the two treatment plants, developed by the Consell Comarcal de la Garrotxa through the SIGMA Consortium, has been completed and the treatment plants are ready to receive wastewater.

The Riudaura treatment plant is designed for a treatment flow of 112 m³/day, but the site includes space for future expansion.

Initially, the wastewater passes through a settling chamber to retain sand. Next, there is a regulation chamber to continuously feed the biodisk. Finally, the biomass is separated in a lamellar settler and the concentrated sludge is sent to a pit for digestion. The entire system can be managed via remote control.

Treatment with biodisks (RBC) has several advantages, such as very simple maintenance and low energy consumption. It is also worth noting that it is a system that works very well in cold places and does not produce bad odors or aerosols since the biodisk is covered. These advantages are compatible with a performance in organic matter removal (BOD5) that can reach up to 98%.

The Oix treatment plant, designed for a flow of 74 m³/day, is already receiving wastewater, and the growth of biomass on the surface of the biodisks has begun, which will allow for the reduction of organic matter.