Balearic Government orders Aena in Ibiza to temporarily halt treated wastewater discharges into Es Codolar stream

The Balearic Government’s Directorate-General for Water Resources, which comes under the regional Ministry of the Sea and Water Cycle, has issued Aena with an order to temporarily halt, as a precautionary measure, the discharge of treated wastewater into the des Cirer stream. The ministry has also stated that the discharge from Ibiza Airport’s wastewater treatment plant into a watercourse running through the Ses Salines Natural Park of Ibiza and Formentera “is not currently authorised”.

The Balearic Government’s move comes in response to a series of complaints dating back to July over sewage pollution in the stream, also known as sa Font, and the section of es Codolar beach where it flows into the sea. On Sunday, Diario de Ibiza published images showing the current state of the area, where a greenish film could be seen on the surface of the water, accompanied by a strong unpleasant smell.

The incidents led to the opening of administrative proceedings, which remain ongoing. Authorities are currently awaiting the results of samples collected during an inspection by environmental officers on 27 July, as well as those taken by the Guardia Civil’s environmental protection unit, Seprona, on 11 August.

“These results will provide further information to determine the causes and allow the investigation to continue”, the Balearic Government said.

Beach closed in August

The issue first came to wider public attention on 7 August, when Aliança per l’Aigua, GEN, Amics de la Terra and several residents’ associations reported that tests commissioned from an authorised laboratory had detected high levels of faecal contamination in water from the area around the airport’s wastewater treatment plant.

The organisations said some readings were well above the permitted limits and announced that they intended to refer the case to prosecutors. Their complaint was based on four sets of samples taken between 12 June and 22 July by a laboratory authorised by the regional health authorities.

According to the results released by the organisations, the samples showed breaches of the limits established for treated wastewater in relation to faecal contamination, with some readings reportedly reaching 17 times the legal limit.

That same day, Sant Josep Town Council temporarily banned swimming along a section of es Codolar beach, opposite the mouth of the stream, after its own tests detected concentrations of E. coli and intestinal enterococci above permitted levels. Following further tests showing that the water was safe, the area reopened for swimming on 11 August.

"It is not reaching the beach"

This time, Sant Josep Town Council said on Monday that the latest suspected discharge “is not reaching the beach”, which is why a new bathing ban has not been imposed.

The council said its latest test found the water to be safe for swimming and announced that it would carry out another round of sampling this week to continue monitoring the situation.

Asked about the possible new discharge, Aena, the state-controlled company that operates Spain’s airports, said that “the management of the beach and the assessment of water quality are the responsibility of the relevant authorities” and insisted that it is “fully cooperating” with all ongoing investigations and inspections.

Since the controversy began, the airport operator has maintained that the airport’s wastewater treatment plant has the necessary permits, contradicting the position taken by the regional Ministry of the Sea.

Aena has also repeatedly said that its water extraction and consumption remain within authorised limits. It has added that during periods of particularly high demand or heavy rainfall, overflow systems at the treatment plant can fill up, allowing already-treated water to escape.

Wastewater treatment plant upgrade

Aena put improvement works out to tender on 12 November 2025 to upgrade the pretreatment unit at Ibiza Airport’s wastewater treatment plant, with a budget of €296,241 before tax.

The contract, under tender reference IBZ-104/2025, was awarded on 13 January 2026 to Hidrogestión S.A., with an expected completion period of three months. The award was made public on 19 January, although there is no record of the works having begun.

According to Aena’s project documentation, the aim is to completely replace the treatment plant’s existing pretreatment unit, whose equipment is described as “obsolete and in poor condition”, resulting in reduced efficiency and greater maintenance requirements.

The project is also intended to increase the plant’s treatment capacity from the current 400 cubic metres per day to 600 cubic metres, a 50% rise, in order to accommodate projected growth in passenger numbers at the airport.

The wastewater treatment plant must remain operational throughout the works. For this reason, the existing system will not be dismantled until the new one has been fully installed, connected and brought into operation.

The old pretreatment equipment will then be removed, the former chamber and pumping well sealed, and the necessary testing and legal certification of the new installation carried out.