Bathing water quality is influenced by urban wastewater treatment capacity which, in the EU, is covered by the Urban Wastewater Treatment Directive (91/271/EEC) (20). Member States have invested significant amounts of money to comply with the standards. This has led to marked improvements in urban wastewater treatment capacity and, in turn, to better bathing water quality (21).
Fig. 5 shows the percentage of the population connected to a wastewater treatment facility with any degree of treatment in 1980, 1995 and 2003 (22). In 2003, the proportion of treated waste-water exceeded 85% in the Nordic and some northern European countries. Southern and south-eastern European countries treated between 40% and 60%, and some of the new EU member states and Belgium treated less than 40%. Describing time trends at the European level is difficult as many countries fail to report data each year. The available data show that many countries have made sig-nificant progress since 1980; these include the Czech Republic, Hungary, Iceland, Poland and Portugal. It is anticipated that the situation will improve significantly with planned increases in the capacity of collection networks and treatment plants.
Fig. 5. Percentage of country population connected to wastewater treatment facilities, 1980, 1995 and 2003
Source: Eurostat (23).
0 20 40 60 80 100
Netherlands United Kingdom (England and Wales) Switzerland Luxembourg Germany United Kingdom (Scotland) Denmark Spain Austria Sweden United Kingdom (Northern Ireland) Finland France Norway Czech Republic Estonia Ireland Latvia Italy Lithuania Poland Hungary Greece Slovakia Iceland Portugal Bulgaria Belgium Cyprus Slovenia Turkey Malta
Proportion of population (%) 1980 1995
2003 or latest available year
EU countries must comply with the EU Bathing Water Directive (2), which requires the monitoring of 19 pollutants and other parameters, including indicators of faecal contamination of the water.
The Directive lays down mandatory standards, as well as guideline standards which Member States are encouraged to meet. The Directive applies to both inland and coastal bathing zones. A revised directive will come into force by 2014 (3).
There is an apparent relationship between the proportion of a population connected to wastewater treatment facilities with at least secondary (biological) treatment and compliance with mandatory and guideline values for inland bathing water quality (Fig. 6).
Fig. 6. Relationship between wastewater treatment coverage and bathing water compliance to mandatory and guide values in fresh water zones.
Source: Eurostat (23); European Environment Agency (24).
Fig. 6 clearly shows the effect of wastewater discharges on microbiological concentrations in inland waters. Around 70% of the variations in compliance with bathing water microbiological standards can be explained by wastewater treatment coverage when the more stringent guide val-ues are considered. In the case of mandatory valval-ues, only 45% of the variations in bathing water quality can be explained by wastewater treatment. The difference is because mandatory values allow for greater levels of contamination and are relatively easily achieved regardless of the treat-ment coverage.
Surface waters can be polluted by sources other than wastewater. Diffuse sources such as runoff from agricultural land and storm water overflows from urban areas can contribute significantly to surface water loads of microorganisms and other pollutants, including nutrients and heavy metals (25). A more thorough approach is needed to control this, and the new EU Bathing Water Directive will prove a useful tool.
0
Population connected to secondary wastewater treatment facilities (%)
Mandatory values
Water quality in both coastal and fresh water zones improved steadily from 1992 to 2005 in the EU (26). For coastal zones, the proportion of sites complying with the mandatory standards in the Bathing Water Directive (76/160/EEC) increased from 80% in 1990 to almost 97% in 2003.
Compliance was lower in fresh water zones, but rose from 37% in 1992 to 92% in 2003. The num-ber of bathing sites monitored also increased consistently over the same period, rising from 10 970 to 14 230 coastal sites and from 5275 to 6685 fresh water sites between 1992 and 2005 (Fig. 7).
Fig. 7. Bathing water quality in the EU, 1990–2005
Source: EC (27).
Despite the significant improvement in bathing water quality, 11% of Europe’s coastal waters and 37% of inland bathing waters still did not meet the more stringent guide values (non-mandatory) in 2005. The differences are partly because inland waters are more sensitive to pollution from point and diffuse sources, the control of which requires structural changes to agricultural and environmental management practices. In coastal waters, self-purification capacity is significantly increased by initial dilution and dispersion due to currents. This protects the waters from becoming contaminated by pathogens at levels affecting human health. Fig. 8 shows the bathing water quality for coastal zones in the EU countries in 2005.
In general, while mandatory standards are often met, guideline standards are infrequently met in coastal and fresh waters. For inland waters, Greece, Ireland and the United Kingdom achieved 100% compliance with mandatory standards. It should, however, be noted that these countries have designated the fewest number of inland bathing waters in the EU (5, 10 and 12, respectively) compared with Germany (1570) and France (1400), which have designated the highest number. In several EU countries (including Belgium, Finland, France and Sweden) which have achieved high compliance with mandatory standards, coastal water quality lags behind the more stringent guide standards. The case of Portugal highlights the role of environmental legislation on improving the bathing water quality (Box 4).
0
Fig. 8. Bathing water quality for coastal zones in the EU, 2005
Source: EC (27).
Box 4. Bathing water quality: the case of Portugal
Portugal took samples from 27% of its bathing waters in 1995 (Fig. 9). At the same time, non-compliance with the mandatory standards was at its lowest (3.8%). Such apparent high compliance was of course misleading due to the low number of samples taken. Because of this, the EC submitted a complaint to the European Court in 1998 (European Court, Case C-272/01). The Government of Portugal improved the monitoring system and implemented a series of management programmes to improve water quality. Sampling rates increased greatly (and are now at 100%), and the percentage of water achieving compliance has risen from 21% in 1998 to more than 95% in recent years (28).
Fig. 9. Bathing water quality in Portugal: developments over time
Source: EC (27).
Proportion of bathing areas (%)
Mandatory requirements fulfilled Guide values followed Insufficiently sampled Mandatory requirements not fulfilled
0
A slight decrease in bathing water quality in coastal zones and a more marked decline in fresh waters was observed in the 2004 and 2005 bathing seasons, when the 10 new EU member states began to submit reports on their bathing waters. It is anticipated that, like the EU15, the new mem-ber states will need some time to implement the Directive fully.
Mandatory standards focus on levels of E. Coli and faecal coliforms, which are used as indica-tors of faecal contamination. Illness may, however, be caused by other pathogens, so that com-pliance does not necessarily indicate that waters are risk-free. Several studies have found that faecal streptococci (another indicator of faecal pollution) is a more useful indicator of the like-lihood of infection; Kay et al suggest that more than 40 colony-forming units per 100 ml of sea-water pose a significant risk of gastroenteritis (29). The new EU Bathing Water Directive (2006/7/EC) lays down mandatory limits for intestinal enterococci, in an attempt to reduce the likelihood of illness (3).