An annual report into sanitation published by Ecologistas en Acción has found that 17 of the 44 treatment plants in Malaga province fail to meet operational standards - around 40 per cent; the worst in Andalucía.
The study, led by Antonio Amarillo, collected data in 2018 from plants which serve more than two thousand people. The biggest which didn't meet standards was that of Antequera where the organisation insists that an expansion is necessary in order to correctly treat wastewater and eliminate pollutants.
The other centres on the blacklist are those in Alcaucín, Alozaina, Archidona, Ardales, Campillos, Canillas de Aceituno, Casabermeja, Casares, Cuevas de San Marcos, Frigiliana, Fuente de Piedra, Humilladero, Teba, Villanueva de la Concepción and Yunquera. In almost all of these cases, insufficient treatment is being carried out and the organisation suggests that either repair or expansion works are necessary.
Amarillo, who carried out the study using regional government statistics, said that there was "a massive shortfall in investment".