Quality of bathing water, 1992-2003
Thermotolerant bacteria in bathing water are an indicator of faecal contamination. Pathogenic bacteria in bathing water can make people ill.
The European bathing water directive requires governments to provide safe bathing areas. There is also the Blue Flag programme, an initiative for encouraging safety and hygiene on beaches.
Policy
The bathing water directive (76/160/EEC) focuses on protecting the health of swimmers. The directive sets out bacteriological parameters (total coliforms and faecal coliforms) with the aim of preventing gastrointestinal illness, together with more aesthetic parameters such as foam, transparency, and odour. The directive also includes requirements for monitoring frequency during the bathing season.
The Blue Flag is an initiative of, among others, the Royal Dutch Touring Club, intended to promote safety and hygiene on European beaches. The critical difference between the Blue Flag and the EU bathing water directive is that the latter does not include testing for faecal streptococci. The EU member states have not yet laid down any statutory standard for this indicator.
The EU has laid down standards in the bathing water directive for testing the quality of bathing water. The limit value or imperative value for the number of bacteria is a maximum of 2000 per 100 ml bathing water. It is expected that this 25-year-old directive will be replaced by a new directive in the years to come. The European Commission has proposed a new bathing water directive that sets stricter requirements for E. coli and intestinal enterococci. As a result, more bathing sites will run into problems, unless still water is regularly replaced with disinfected water. Measures for reducing overflows and the eutrophication of surface water have also had a beneficial effect on the quality of bathing water.
The bathing water directive requires bathing water quality to be assessed using two sets of parameters. The strictest set consists of guide values, or indicative values. The other set consists of binding, or imperative, values. There is an infringement under the terms of the directive only if the values measured exceed the imperative values.
http://europa.eu.int/water/water-bathing/directiv.html
Developments
The indicative values show that the quality of coastal waters is generally better than that of inland waters. If the imperative or limit value is exceeded, the authority must take action to reduce the contamination. The number of bathing sites in the Netherlands that met the limit value for bathing water quality fell between 2000 and 2001. Before then, the quality of the bathing water actually improved. The downturn in 2001 is possibly the result of the excessive rainfall in that year. In 2002 and 2003, there were only three bathing areas where there was a bathing ban as a result of the water quality. In 2003, the conditions were very favourable for bathing water quality: the weather was dry and warm.
Because microbiological water quality in seven coastal municipalities in the provinces of North and South Holland failed to meet the standards for faecal streptococci in 2002, they were not awarded the Blue Flag that year. Further investigations have identified the burden from sewer overflows, and occasionally from the run-off and leaching of fertilisers, as the causes (de Kok, 2003).
Relevance
Surface water is often polluted by human or animal excrement. As a result, pathogenic micro-organisms - in other words organisms that can cause illness - infect the water. Examples of micro-organisms of this kind are Cryptosporidium, viruses, such as Norwalk-like caliciviruses, and toxic algae.
