In 2011, the Catalan Water Agency decided to construct the Camp de Tarragona Water Reclamation Plant. This plant treats municipal secondary effluent collected from two urban wastewater treatment plants (WWTP Tarragona and WWTP Vila Seca-Salou) and generates 6.8 million m3 of reclaimed effluent per year for use in water for cooling towers and boilers at the local petrochemical complex.

This approach was supported by the Chemical Business Association of Tarragona (AEQT) and Tarragona Industrial Water Company (AITASA) that represented the trade and technological needs of the industrial end-users operating at the Complex, such as Dow Chemical and Repsol. The project was financed by the EU Cohesion Funds (85%) and the Catalonian Government and the Spanish Ministry of the Environment (15%).