You can swim at the Nallikari Beach again – the bacterial counts have gone down


Updated on July 12, 2024 at 14.15.

The amounts of Escherichia coli bacteria found in the samples taken from the Nallikari Beach on July 10 and 11 did not exceed the action level. The amounts of enterococci bacteria have not exceeded the action level at all during the situation. The recommendation to avoid swimming at the beach is lifted. 

The E. coli bacteria content of the sample taken from the Nallikari Beach on July 10, 2024, was 430 mpm/100 ml and on July 11, it was 20 mpn/100 ml. 

The Environment Office of the Oulu Region has increased the intensity of observation of the water quality at the Nallikari Beach as planned. The next sample will be taken on the week of July 22 according to the observation schedule. Its results will be announced by the end of that week. 

The recommendation to avoid swimming was given on July 10 since the Escherichia coli bacteria content of the samples taken on July 8 and 9 exceeded the action level.  

Many factors can affect the quality of swimming water 

It is possible that the strong winds and heavy rain over the weekend (July 6–7) have affected the quality of swimming water. They could have brought or raised bacteria into swimming water. 

The shallowness and low turnover rate of the water could also have affected water quality. It is also possible that the bacteria originate from swimmers, which is why people with stomach illnesses should not go swimming. Other external sources could also be boat traffic and animals. It is not always possible to find a single source of low water quality. 

Report cases of illness 

If you have symptoms or you suspect you got ill after swimming, please inform Environmental Health Care at the address   

Background information of the action levels 

The quality of swimming water is defined by the levels of so-called indicator bacteria (E. coli and intestinal enterococcus). The indicator bacteria indicate the amount of fecal contamination. The indicator bacteria do not necessarily cause stomach or other symptoms. But if many symptoms occur it is possible that there are other bacteria or viruses that cause illnesses in the swimming water. 

Indicator bacteria Inland water Coastal water 
 (pmy or mpn/100 ml) (pmy or mpn/100 ml)
Intestinal enterococcus 400200
E. coli (Escherichia coli) 1 000500
Cyanobacteria (Blue-green algae) Observed in the swimming water or on the beach Observed in the swimming water or on the beach 


Health Protection Act 763/1994 

Ministry of Social Affairs and Health’s Decree 177/2008