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A2.2      European results

General information

According to the drinking water quality data of reporting period 2011 to 2013 in the EU, the volume of water supplied divided by number of resident population is about 220 l. This is much more than the mean water consumption per person and day, because drinking water supply for industry or other uses than human consumption is included. The water consumption varies between Member States; for example it is about 81 l in Slovakia, 150 l or less in Denmark and Hungary, and more than 200 l in Austria, Bulgaria, Cyprus, Finland, France, Greece, Ireland, Italy, Luxembourg, Portugal, Romania, Slovakia, Sweden and the United Kingdom. The high consumption level also includes water for agriculture and/or industry in many cases. This water comes from various sources, mainly groundwater or surface water (e.g. drinking water reservoir). Overall, the main source in EU’s countries is groundwater, which provides some 50 % of the total (Figure A2.1). Figure A2.2 shows the percentages of water sources in EU Member States (before Croatia’s accession).

Figure A2.1 Sources of drinking water in the EU, 2011–2013.

Figure A2.2 Sources of drinking water, 2011–2013.

*In the Czech Republic, inland water is synonymous with surface water.

Figure A2.3 shows the percentage of resident population in large water supply zones (> 1 000 m³ per day and/or supplying more than 5 000 people). Some countries also reported the resident population of small water supply zones for in 2011–2013. If we add those, the total proportions of residents supplied are 100 % in Bulgaria, France, Hungary, Malta, Portugal and Slovakia; 96 % in Belgium; 95 % in Cyprus; 93 % in Spain; 90 % in Slovenia; 85 % in Ireland; and 66 % in Romania.

Figure A2.3 Population with access to large water supply zones, 2011–2013.

Drinking water quality

To assess drinking water quality in water supply zones, Member States carried out a huge number of analyses in the reporting period 2011–2013: microbiological parameters (4.1 million analyses), chemical parameters (7.1 million analyses) and indicator parameters (17.5 million analyses).

For each parameter, information on compliance was available. Percentage of compliance reflects the ratio between the number of analyses and the number of exceedances. Compliance with the Directive means that more than 99 % of all analyses meet the given standard. Exceeding indicator parameters does not necessarily mean non-compliance with the directive, for the reasons mentioned in section A 3.1, but only if there is no direct threat to human health.

Figure A2.4 shows the percentage of compliance for the parameter groups: microbiological, chemical and indicator parameters. The results show high compliance rates for microbiological and chemical parameters. Indicator parameters reached almost 99 % compliance in the reporting years 2011–2013. The indicator parameters covered exclude colour, odour, taste and turbidity, which do not have numerical values.

Figure A2.4 Percentage of compliance for microbiology, chemicals and indicator parameters in the EU.

Figure A2.5 shows information on compliance for the chemical parameters in the EU.

Figure A2.5 Compliance rates for the chemical parameters in the EU, 2011–2013.

At 98.83 %, arsenic shows the lowest compliance rate. This is mainly caused by geological background concentrations in the catchment areas.

Figure A2.6 shows information on exceedances for indicator parameters. The figure just gives an overview of the exceedances. It does not reflect non-compliance with the directive, because a number of indicator parameters do not have a numerical value, such as colour, taste, odour or turbidity.

The most frequent exceedances in the indicator parameter group are for total organic carbon, iron, sulphate and manganese.

Figure A2.6 Compliance rates for the indicator parameters in the EU, 2011–2013, excluding colour, taste, odour and turbidity.

Box A2.1 reflects the importance of pesticides as a potential risk for drinking water quality.

Box A2.1 Pesticides in drinking water

Pesticides can be ‘contaminants of concern’ for aquifer recharge, and mainly reach aquifers from agricultural run-off.

Much effort has been put into standards for pesticide levels in drinking water. The standards use an indicator approach and do not really reflect acceptable concentrations for health. The DWD sets a concentration limit of 0.1 μg/l for individual pesticides, and the sum of the pesticides must not exceed 0.5 μg/l. Because pesticides are present on a regular basis and in low concentrations, exposure to these chemicals is generally chronic. The health risk is difficult to assess, because data on acceptable doses for chronic exposure are scarce and the low concentrations involved are difficult to monitor.

Member States monitor a huge number of national specific pesticides and metabolites in drinking water. However, the EC and Member States agreed a short list of 13 pesticides for which the Member States reported monitoring frequency and non-compliance in 2011–2013. The short list is a harmonised approach and makes reporting comparable, but does not show the full picture of all pesticides and all relevant metabolites in a country.

The following figure shows the percentage of large water supply zones in the EU, where monitoring of the listed pesticides have been carried out in the reporting period 2011–2013.

Admitting that monitoring is low, compliance rates are consistently high. The compliance rate is more than 99.9 % for pesticides in total, but 99.6 % for individual pesticides (see Figure A2.5). These include the region-specific substances and all relevant metabolites.

Protecting raw water is particularly important. Critical groundwater bodies need special attention from specific measures for drinking water. That cannot be the task of the water suppliers alone. Rather, various stakeholders need to cooperate closely to plan and implement measures in the catchment area. To protect drinking water against pollution from the catchment area, there must be a well-integrated link between the DWD and the other water-related directives, such as the WFD and the BWD.

Causes of non-compliance

The reporting obligations mean that, if a water supply zone does not comply, Member States need to report causes and remedial actions. The number of causes depends on the number of non-compliant analyses.

Failures suspected of being caused by contamination of the source water are defined as ‘catchment related’. These causes include discharges from wastewater treatment plants or stormwater overflow (see also Chapters 3 and 6), agricultural activities (use of fertiliser and pesticides) and industrial activities. Treatment-related causes are mainly associated with the treatment processes at the plant, such as chemical dosing regimens, coagulation and clarification procedures, filter operation or disinfection. Within the distribution network, causes of contamination could be flow reversals and pressure changes, changes in the flushing or scouring regime, or leakages. Failures associated with the domestic distribution network can be identified only at the consumer’s tap. Non-compliances with the standards for copper, lead and nickel at the consumer’s tap may be associated with the consumer’s pipes and fittings.

Figure A2.7 shows the main parameters that exceeded the parametric value and that had causes reported. During the reporting period 2011–2013, most of the reported causes of exceedances were for coliform bacteria. A number of causes were also reported for iron, microbiological parameters other than coliform bacteria, total organic carbon, ammonium and manganese. Most of these are indicator parameters that pose no direct threat to human health.

Figure A2.7 Number of analyses with reported causes of exceedances for the parameters of the DWD in the EU, 2011–2013.

Figure A2.8 shows the different causes for the most reported parameters. Causes of exceedances due to biological parameters (coliform bacteria, colony count, E. coli, enterococci, clostridium) and iron cannot be exactly specified, exceedances of ammonium, manganese, pH, chloride, sulphate, arsenic and nitrite are mainly related to the catchment. Total organic carbon and aluminium mainly come from treatment, whereas lead is clearly associated with problems in domestic distribution networks. (So is nickel, which is not shown in the figure.)

The problem of nitrite and the nitrate/nitrite formula is widely discussed. The figure shows a rather small number of reported causes. They are obviously related to the catchment and are less prone to sudden impacts within the source area. Pre-selection and combination of higher-quality raw waters usually mitigate them.

Figure A2.8 Causes of non-compliance for the most reported parameters of the DWD in the EU, 2011–2013.