According to the report published by the Water Alliance, Menorca is the island with the highest level of non-compliance, with 26,1% of unsuitable analyses; Mallorca has the largest number of inhabitants affected by chronic nitrate non-compliances; Ibiza records non-compliances and drinking water at risk due to the salinization of aquifers.
The Alliance for Water has today published an assessment of the quality of water for human consumption in the Balearic Islands, as a preview of its annual report. This study is part of its Balearic Islands Water Observatory project and has been prepared based on data from the National Drinking Water Information System (SINAC) of the Ministry of Health. The conclusions are worrying: in 2025, 98.452 registered inhabitants of the four islands lived in areas where the water was declared unfit for consumption at some point in the year. And these are not isolated episodes: in several of these areas the breaches have been repeated year after year since 2016 or 2017 without interruption. If we add the 22 additional "at risk" areas - suitable, but with recurring breaches that may precede non-suitability -, the total figure reaches 145.027 inhabitants, a volume that the entity denounces as a direct consequence of the overexploitation and continuous salinization of aquifers, caused by decades of urban growth and limitless demographic pressure.
The report evaluates the 67 municipalities of the Balearic Islands and analyses 992 analyses from 2025. The overall level of non-compliance is 9,4%, but this percentage hides notable differences between islands and, above all, the existence of areas with non-compliance that are repeated year after year without being remedied. The Water Alliance warns that, in many cases, these are not isolated episodes but structural problems linked to overexploitation, salinization and nitrate pollution of aquifers, due to increased urban and population pressure and, in the case of nitrates, also due to agricultural activity.
"This cannot be solved with more chlorination or more analyses. As long as we continue to grow, urban and in population, we will continue to overexploit and salinize aquifers, and there will be towns that will never be able to guarantee quality water to their neighbors. What comes out of the tap is the symptom; the disease is underground," says Rafael Tur, spokesperson for the Water Alliance.
Mallorca: 70.357 inhabitants without a continuous guarantee of safe water
In Mallorca, 26 supply areas spread over 13 municipalities recorded at least one unsuitable analysis in 2025, affecting 70.357 registered inhabitants. The level of non-compliance with the analyses of the supply areas of Mallorca during 2025 is 9,2%. The Alliance for Water highlights two clearly differentiated geographical patterns: in the agricultural interior —Manacor, Sineu, Ariany, Costitx, Vilafranca de Bonany, Lloret de Vistalegre, Llubí and Petra— the dominant parameter is nitrate, with non-compliances that have been repeated year after year since 2016 or 2017 without interruption. On the coast of Santanyí, on the other hand, the pattern is of saline intrusion: chloride, conductivity, sodium and sulphate above the parametric values. In addition, 12 areas of Mallorca that serve 37.601 registered inhabitants are at risk, including Llucmajor (11.418 inhabitants) and Can Picafort (8.869 inhabitants), which accumulate recurrent sodium and conductivity violations.
Menorca: the worst non-compliance rate of the four islands
Menorca is the island with the highest level of non-compliance in the archipelago, with 26,1% of the analyses not suitable in 2025. Ten supply areas spread over three municipalities —Maó, es Castell and Ciutadella de Menorca— had unsuitable water, affecting 22.705 registered inhabitants. The Water Alliance warns that the area around Maó has seven unsuitable areas, all with a dominant pattern of nitrates that has been repeated almost uninterruptedly since 2016. In Ciutadella, the problem is mixed: chloride and nitrate combined, consistent with the "Poor" state of the groundwater body in the area, exploited above 104% of its natural recharge capacity. In addition, 3 areas of Menorca are at risk and affect 4.678 registered inhabitants: Ciutadella Urban Area Network (3.878 inhabitants) due to increasing conductivity, and Urbanization Son Parc (564 inhabitants) and Santo Tomàs (236 inhabitants) due to recurrent non-compliance with residual free chlorine.
Ibiza: 5.390 inhabitants affected and two areas that have been in non-compliance since 2016
In Ibiza, 6 supply areas in three municipalities recorded unsuitable water in 2025 and affected 5.390 inhabitants: Cala de Bou-Port des Torrent (Sant Josep, 4.918 inhabitants), Vicent Ribas-Ferreret (Sant Antoni, 229 inhabitants), Can Aubarca (Santa Eulària, 121 inhabitants), Cala Mastella (Santa Eulària, 53 inhabitants), Es Canar Cosmi (Santa Eulària, 35 inhabitants) and Sant Josep Zona I (Sant Josep, 34 inhabitants). It should be noted that much of this non-compliance occurred in Cala de Bou, where the Cala de Bou-Port des Torrent supply area, the most populated in Sant Josep de sa Talaia, recorded bromate levels above the parametric value in July 2025. Bromate is a by-product of disinfection that can appear when the water contains bromide, a natural component of seawater. The Water Alliance does not rule out a relationship with the marine intrusion already documented in the aquifers of the area, although the available data does not allow this to be confirmed.
The entity underlines that the two areas with the most worrying history, Sant Josep Zona I (13 unfit analyses since 2016) and Es Canar Cosmi (8 since 2016), remain unresolved and show the classic pattern of saline intrusion: conductivity, sulphate and chloride well above the parametric values, consistent with the overexploitation of their aquifers, some of which have been exploited above 108-119% of their natural recharge. In addition, 6 additional areas of Ibiza are at risk, with 4.296 inhabitants: Siesta, Cala Llonga, Urbanización Buenavista and Montañas Verdes, all in Santa Eulària des Riu, and Urbanización Isla Blanca (Sant Joan de Labritja) and San Rafael (Sant Antoni de Portmany), with recurrent sulphate breaches that, in previous documented cases, preceded the classification as unfit.
Formentera: no breaches, but with an area under surveillance
Formentera is the only island without any supply area with unfit water in 2025. The Alliance for Water highlights that this good compliance is largely due to the fact that drinking water consumption on the island is mostly of desalinated origin, given the historical overexploitation of the Formentera aquifer, which has made it unviable to rely exclusively on groundwater. However, one area, Distribució Riu La Mola, is at risk due to recurrent non-compliances of residual free chlorine since 2023, an indicator of dosing problems in the distribution network.
The Water Alliance calls for urgent political action
The Water Alliance considers that the data in this report highlight a public health problem that the administrations cannot continue to ignore. The entity addresses, first of all, the Ministry of Health of the Government of the Balearic Islands, as the health authority responsible for the control of water for human consumption. The Alliance demands that it verify that all operators in areas with chronic non-compliance have a Water Health Plan (PSA), mandatory for all supply areas in accordance with Royal Decree 3/2023, and an updated Self-Control Protocol, mandatory without exception for all areas since Royal Decree 140/2003. Both instruments, designed precisely to identify and correct risks in advance, have not prevented areas such as Sant Josep Zone I or Es Canar Cosmi from accumulating non-compliances since 2016 without resolving them.
The organization calls on the Ministry of the Sea and the Water Cycle, responsible for ensuring the control and recovery of water resources, to effectively control groundwater extraction and to urgently implement the necessary measures to restore the good state of the aquifers in accordance with the current Hydrological Plan of the Balearic Islands. The Water Alliance also calls on the municipalities, directly responsible for the supply of drinking water to their residents in accordance with the Local Government Bases Law, to require their operators to comply with legally binding plans and protocols, and not to authorize new urban developments without first guaranteeing the availability of sufficient and quality water.
The Water Alliance recalls that the declaration of unsuitability and consumption recommendations correspond to the health authority, and that residents of the affected areas must at all times follow the instructions of their city council and the Ministry of Health.
The entity stresses that the most urgent and structural measure is to limit urban growth and demographic pressure, as an indispensable precondition to stop the overexploitation and salinization of aquifers, the main natural water resource that supplies the towns and cities of the Balearic Islands. According to the Hydrological Plan of the Balearic Islands, 60% of the underground water bodies of the islands are already in poor condition due to overexploitation, salinization or nitrate pollution, a situation that will only get worse if action is not taken on the causes. In this sense, the Alliance warns that the recent Law 4/2026, or omnibus law, goes in the exact opposite direction: it reduces the obligation to request a water sufficiency report for new urban growth, and thus deactivates the main environmental control over growth at the worst possible moment.
The results can be consulted in the following incident map prepared by the Water Alliance:
