Mallorca wastewater jumps 15.1% as plants strain

Wastewater flowing into Mallorca’s treatment plants rose 15.1% between 2021 and 2025, adding to the strain on the island’s sanitation system. On 4 September, the Water Alliance said population growth and mass tourism were pushing treatment plants across the Balearics towards their limits. Plants managed by Abaqua treated 49.3 hectometres cubed of wastewater in 2025.

The alliance links the pressure to the number of people on the islands. Between 2016 and 2025, the resident populations of Mallorca, Menorca and Eivissa rose by between 12% and 16%, while the Human Pressure Index increased by between 7% and 9%.

It warned that many plants were not designed for today’s population.

Eivissa gains a new plant but faces saltwater problem

Wastewater entering Eivissa’s plants increased by 6.8% between 2021 and 2025, the lowest rise among the four islands. But the Water Alliance said the island has the report’s most worrying quality indicators.

The Cala Tarida and Can Bossa treatment plants have operated above 95% of their annual volume since 2021. The new Sa Coma plant, which replaced the old Vila facility after works finished in 2024, now handles almost half of Eivissa’s flow and meets all the criteria.

Seawater leaking into the sewer network makes wastewater harder to clean and prevents it from being reused, the alliance said.

Formentera’s flow falls, but renewal is due

Formentera was the only island with no recorded non-compliance. Wastewater entering its treatment plant fell by 19% between 2021 and 2025.

The facility still needs renewal, though it has never been too small for demand. Its incoming water remains among the poorest-quality on the islands: 52.8% exceeded the salinity limit in 2025, down from 100% in 2024.

Topics: Tourism · Sant Llorenç des Cardassar

Source: Europa Press / Mallorca.com