The €5 million project is being undertaken by Veolia’s UTEDEZA which is in charge of operating the WWTP for the Ayuntamiento de Zaragoza.
 
The La Cartuja WWTP will be equipped with Veolia’s ACTIFLO DUO process. This ballasted settling process using microsand was designed for a treatment capacity of 2.6 cubic metres per second. It will be used first to treat excess water flow that reaches the plant during rain or storms before being released into the Ebro river and for secondary scrubbing to remove suspended solids and to ensure the right COD of the final effluent if the WWTP becomes overloaded. This process will also be able to operate as a conventional MULTIFLO settler for the treatment of return water.