Quality of water intended for human consumption. Drinking Water Directive

Under Directive 98/83/EC on drinking water, the Commission presents a synthesis report on the quality of drinking water in the Union.

Member States are obliged under the Drinking Water Directive to monitor on a regular basis the quality of the drinking water that is supplied to consumers. They have to report triennially the monitoring results to the Commission.

This synthesis report gives a summary of the drinking water quality in EU Member States in 2011-2013. The Directive makes a distinction between large and small water supplies. Large water supplies provide either more than 1,000 m³ drinking water per day as an average or serve more than 5,000 persons.

During the data collection exercise, 15 Member States provided on a voluntary basis also information on small water supply zones (supplying less than 1,000m³/day). An overall EU assessment of compliance in small supplies was not considered meaningful as the data available was not fully representative for the entire EU and therefore this information is not included in the present report. According to the information provided by these 15 Member States the overall compliance is on average 98% high and no major problems are indicated.

The main conclusion of the synthesis report shows that compliance rates for parameters directly reflecting the quality of the drinking water supplied to consumers reached with one exemption at least 99 % for the first time in all Member States during the 2011-2013 reporting period. This is a positive achievement that reflects the efforts made by all concerned for the correct implementation of the Drinking Water Directive.

Drinking water quality – Compliance: to assess drinking water quality in a water supply zone, a very large number of analyses have been carried out within the 2011-2013 reporting period in Member States: 4.1 million on microbiological parameters, 7.1 million on chemical parameters and 17.5 million on indicator parameters:

• as regards the microbiological parameters, all Member States reported between 99-100 % rate of compliance;
• concerning the chemical parameters, 26 Member States reported compliance of between 99-100 %, and only Hungary reported compliance just below 99 %;
• for the indicator parameters, three Member States had a compliance rate between 98 % and 100 %, three Member States show a compliance rate of less than 98 % and 21 Member States reached a compliance level of over 99 %. For indicator parameters, Malta reported a rather low mean compliance rate of 90.1 % because of very low compliance rates on chloride.

Remedial actions: the report presents these measures for three important parameters coliform bacteria, arsenic, and lead:

• for coliform bacteria contaminations detected, the majority of the remedial actions taken (67 %) were related to the public distribution network or treatment infrastructure and operation (i.e through better disinfection);
• remedial actions to minimise high concentrations of arsenic in drinking water were mostly related to treatment (46 %) or catchment (29 %);
• in the case concentration of lead exceeds the parametric value, 67 % of all reported remedial actions consisted of the replacement or disconnection of lead pipes in the domestic distribution network.

The report noted that problems in relation to specific drinking water quality parameters or groups of parameters find their cause at different points of the drinking water supply chain: water source, treatment, distribution and end of pipe - the consumer. This suggests that useful monitoring programmes should be set up considering these different causes of non-compliance at different points.

The Commission recalled that when continuing non-compliance due to structural problems is observed, and remedial action was not sufficient to restore the quality of drinking water, the Commission can take action on a potential case of violation of Union law.

The Commission attempts to quickly resolve the underlying problem with the Member State concerned by means of a structured dialogue, and if the Member State concerned fails to implement a solution to rectify the suspected violation of EU law, the Commission may launch a formal infringement procedure. Due to the overall high compliance this has been necessary in only a few cases so far.

Next steps: the Commission stated that at the time of publication of this report, a detailed evaluation report on the Drinking Water Directive is being drafted, which assesses inter alia also the reporting system. In parallel, a Fitness Check of EU environmental monitoring and reporting is being carried out. Both these initiatives are likely to include further conclusions and follow-up to improve the reporting process under the Drinking Water Directive.