Water quality update in Roses | Oct 31
31/10/2025 11:39
The City Council, together with the Consorci d’Aigües de la Costa Brava, AGBAR and the Department of Health of the Generalitat, is continuously monitoring trihalomethane (THM) levels from the analyses of the municipal drinking water supply.
Latest THM analysis results
| Date | THM (μg/L) |
|---|---|
| 7 October | 111 |
| 10 October | 96 |
| 14 October | 92 |
| 17 October | 102 |
| 21 October | 82 |
| 24 October | 72 |
| 28 October | 67 |
While there has been a considerable decrease in THM levels and the last three analyses are below the limit set by RD 3/2023 (100 μg/L), the recommendation remains in place not to drink tap water without following the established guidance, until further notice.
Verifying the effectiveness of the measures
To bring trihalomethanes below the regulatory threshold, the Consorci d’Aigües de la Costa Brava has replaced chlorine gas used for disinfection with chlorine dioxide, a more water-quality-friendly agent that does not produce trihalomethanes when in contact with organic matter.
For optimal results, this substitution must be implemented progressively, as has been done over recent weeks.
Work is ongoing towards a definitive resolution of this issue, with an increased frequency of analyses to validate the proper operation and results of the new chlorination system, so that the consumption restrictions can ultimately be lifted with full guarantees.
The City Council will continue to monitor the situation and inform residents of any changes. Until further notice, if tap water is consumed, please follow the established recommendations.
Recommendations on the consumption of water from the Roses supply network | News - Port Roses
