The European Commission has issued an ultimatum to Spain regarding the dumping of solid industrial waste in the Huelva estuary.
The EU says that nature is not a dumping ground for waste and that member states should manage such waste in ways that respect the environment.
This is the second stage of proceedings against Spain. If there is no resolution to the problem within two months, the case will be referred to the Court of Justice in Luzembourg.
The Commission contents that Spain has allowed the storage of industrial waste in violation of European environmental legislation on waste prevention, disposal and integrated pollution control.
For forty years, fertiliser manufacturers have dumped industrial waste into the marshes near the city of Huelva. In total, 120 million tons of phosphogypsum, a substance produced when the phosphate reacts with sulphuric acid to produce fertiliser, have been dumped in a 1,200 hectare area.
Waste management companies received licenses in 2008 but the European Commission believes that by not actually considering phosphogypsum as industrial waste, the Spanish authorities continue to violate EU environmental laws.