Ourense WWTP: Enhanced Sewage Treatment in Ourense


On July 26 2017, the Spanish minister of Agriculture, Fisheries, Food and Environment, Isabel García Tejerina, inaugurated the new Ourense Wastewater Treatment Plant (WWTP). At the ceremony, the minister emphasised that the new facility responded to the stringent demands of good urban water cycle management, which is “an essential element of solid, sustainable development”.

The EDAR Ourense consortium, made up of Copasa, Suez and Pesa Medio Ambiente, was awarded the contract for the design, construction and commissioning of the new Ourense WWTP. A total of €59 million was invested in the project, which was co-funded by the Ministry, through state company Acuaes, the European Regional Development Fund, the Regional Government of Galicia, through Augas de Galicia, and the Ourense City Council. This investment has provided the city of Ourense with an infrastructure that enables compliance with European

Directives on wastewater treatment.

The construction work at the new WWTP was carried out by Acuaes and the facility will serve a population equivalent of over 350,000, compared to the previous capacity of 88,000 p.e. The maximum daily treatment flow will be tripled, from 24,640 m3/d to 72,000 m3/d and the new plant will also enable the treatment of 100% of the stormwater received at the facility.

Main work undertaken

The main work undertaken in this project is as follows and more detailed information on each element will be provided later in this report:

Enhancement of inlet line

The final 700-metre section of the inlet sewer line was built and the diameter of this section was increased to 1,500 mm, enabling an increase in the volume of water carried from the connecting sewer line on the right bank of the River Miño.

New Ourense WWTP

The Ourense WWTP is designed not only to ensure compliance with discharge requirements but also to adapt to the terrain of the site on which it is located, with a view to reducing earthwork requirements, environmental impact and the scheduled completion period. The project was finally carried out within a period of 30 months.

Proven, cutting-edge technologies were implemented in both water and sludge lines for the purpose of best achieving the design objectives. Chief amongst these objectives are:

• Reducing energy consumption
• Increasing energy production
• Reducing the quantity of bio-solids produced
• Recovering sludge for agricultural use
• Reducing chemical reagent consumption
• Reducing odour emissions and the volume of air requiring odour control treatment

Read the complete Plant Report



Director of Public Works at ACUAES

Published in: FuturENVIRO #43 September 2017