The Arazuri WWTP treats the waste waters generated in the Pamplona area and discharges the waters into the river Arga.

The system’s primary treatment dates back to 1990. in 1999, Cadagua was responsible for the design and construction of the biological treatment system, which included nutrients removal and anaerobic digestion, which in turn provided opportunities for cogeneration and energy recovery.

A notable feature are the 6 large secondary clarifiers of 48 meters in diameter and 7,700 m3 capacity.

Type of treatment

Biological treatment of activated sludge with elimination of N, Cogeneration.

Main features

Location: Navarre, Spain

Equivalent population: 500.000

Capacity: 129.600 m3/day

Year: 1999