Water sampling for the Swedish Tourist Association
In the river Enan, which is located in the western Jämtland mountains, high levels of E. coli bacteria have been measured for several years, during certain periods. The Swedish Tourist Association, STF, which has the mountain stations Sylarna and Blåhammaren in the area, wanted to ensure that it was not their facilities that caused the emissions and therefore hired IVL's environmental consultants to make measurements and take samples.
It is in late summer and autumn that the local water management association has measured elevated levels of the bacterium, and these are recurring high levels for several years. E. coli is an intestinal bacterium that normally should not be present in such high levels in the river. Common sources of emissions for E. coli can be agriculture and sewage treatment plants.
- As we are the only major players in the area, we hired IVL to ensure that the wastewater from the mountain stations did not release any E. coli bacteria and was as clean as possible. Even though our own measurements showed that this was not the case, we wanted to bring in an external party. And above all, also investigate that there were no weaknesses in our systems, says Mats Isfjäll who is responsible for the operation of the sewage systems at STF.
Water samples in sewage, in the river and inflows
IVL's environmental consultants have taken samples of incoming and outgoing wastewater. Water samples have also been taken in the river Enan and some of the inflows that come from the mountain stations to see if the impact from the sewage treatment can be measured in the mountain streams.
- We can state that there is nothing to indicate that the E. coli bacteria in the river come from STF's mountain stations. Even in situations with a very high load, the bacteria in the river could not be traced to the facilities, says Johan Strandberg at IVL Swedish Environmental Institute.
Where the high levels come from is still unclear at present.
Proper handling of the sewage system
The visitor pressure at STF's mountain stations has increased and in line with this, the sewage systems must be adapted. At STF Sylarna, a new sewage plant with an advanced biological treatment stage has been installed and at STF Blåhammaren, the existing plant has been improved. An additional measure that STF takes is to improve its own control and ensure the operation of the facilities. The plant at STF Blåhammaren was for a period affected by operational disruptions and then temporarily released too high levels of nitrogen and phosphorus.
- Measures are needed here to prevent this from happening again. It is important to ensure, not only that you have the right treatment plant, but also that it is managed correctly, says Oscar Samuelsson, researcher in wastewater treatment at IVL Swedish Environmental Institute.
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