Corpi Gia SL has obtained the highest score in the public tender for the award of the
construction of the WWTP in the municipalities of Riudaura and Oix.
The construction project for the two treatment plants, developed by the Consell Comarcal de
la Garrotxa through the Consorci SIGMA, proposes the biological treatment with rotating
The Riudaura sewage treatment plant will be designed for an influent flow rate of 112 m3/d
and the location provides space for future expansion.
Initially, the influent wastewater will pass through a settling chamber to retain grit and sands.
Next, there will be a regulation chamber to continuously feed the biodiscs. Finally, the biomass
is separated in a lamellar decanter and the concentrated sludge is sent to a pit to digest them.
The entire system can be managed by remote control.
In the case of the Oix treatment plant, the treatment scheme is the same for a flow rate of 74
m 3 /d.
Treatment with biodiscs has several advantages such as very simple maintenance and low
energy consumption. It should also be noted that it is a system that works very well in cold
weather and that no bad smells or aerosols are produced since the biodiscs are covered. These
advantages allow, at the same time, a high performance in organic matter removal (BOD 5 ) that
can reach 98%.
Completion of the work is scheduled for the last quarter of 2023.