A study by researchers from the University of Huelva and the Andalusian Institute of Earth Sciences of the University of Granada-CSIC confirms that there is a connection between the phosphogypsum ponds and the Rio Tinto estuary, which contributes to the pollution of this .
The study, published in the journal ‘Water Research’ , discards that the process water piled on the surface of the ponds, initially used to transport the waste, is “the main and only pollutant.”
This is also due to the construction of the rafts, which are arranged directly in the marshes of the Huelva estuary, without any impermeable barrier to prevent leaching.
The researchers considered it necessary to carry out more studies to validate the contamination pathway, for which they used stable isotopes as geochemical tracers.
The results have ruled out, according to the research, advanced by the Cadena Ser, stagnant process water as the main vector of contamination by the trailing edge and have revealed “a continuous infiltration of estuary waters to rafts that imply that is subject to an open weathering system. “
Specifically, the water from the Tinto River goes deep into the rafts when the high tide occurs and returns to the estuary -with the low tide- loaded with leachates.
Therefore, the study suggests that the access of intertidal water within the phosphogypsum ponds, for example through secondary tidal channels , is the main responsible for the thorough erosion of the waste.