NIRAS - Aurélie

Index page
Task6 (index)



Situation in Denmark (for swimming water treatment)


Summary of the interview of Linda Bagge from the Danish EPA (26/07/06)

In Denmark the majority of the swimming pools are using chlorine as a disinfectant. Some are using Ultra-Violet, one in Jutland is using ozone and another one also in Jutland is using copper-silver ionization. While by-products of chlorine (chloramines and THMs) have been reported to be the cause of health problems, alternatives of chlorine are not really used here in Denmark. So, some barriers may exist.


The local authorities are responsible for the agreement of a swimming pool. They also approve the disinfection technique used to treat the water. The disinfection technique has to meet certain demands according to the Danish legislation: levels of free chlorine, bounded chlorine and total chlorine; level of THMs (trihalomethanes), temperature and pH. Thus, the owner of the future pool has to make some experiences or some literature research and then make a report to the local authority to prove that the technique he wants to use will meet these demands. He has to prove that the by-products will be removed or reduced to a level below the health effect limit. This could be a long and hard work especially for alternatives to chlorine because there are little references here in Denmark. Consequently, that is why there is only one ozonated swimming pool. According to the Danish EPA this is the main barrier because one has to prove that the consequences with the alternative will not be more important than those with chlorine. The other barrier is the cost of alternatives techniques, especially ozone system. The majority of the swimming pools are owned by municipalities and they can not sometimes afford for an ozone system. Besides, when an existing swimming pool is going to be remodeled it is not always easy to change the disinfection treatment (construction of a technical room…). These are the main reasons why there is not much more ozonated swimming pools in Denmark.


Currently, the Danish EPA is working on trichloramines. They are making a risk assessment to know if trichloramines is responsible of asthma in swimming pools. They are also working on alternatives to chlorine through a literature research and it will be finished in a month. A year ago, they have made a risk assessment of THMs.


The European Union does not take any position about disinfection treatments. There is not any legislation. There are some guidelines proposed by the WHO (pH, amount of bacteria… according to the different techniques) that can be used by the European countries to make their own legislation. In Germany, there is the DIN standard which is very famous. European conferences about swimming pools also take place sometimes. The next conference will next year and the subject will be the by-products and the chemicals. These conferences are in connection with the WHO and authorities, companies and universities attend them. The objective of these conferences is not to make European standards, people just share their knowledge.




You can send comments :


Started by NIRAS supervisor Sergio Fox on 27th March 2006.