Of the total of 21 water samples this year fell 19 in the two highest classes of the four-level quality scale, as the cantonal laboratory announced on Tuesday. Two samples were assigned to the second worst class, a health disorder can not be excluded.
Three samples were taken at the seven measuring points on the Rhine, Birs and Wiese, which were examined for coliform bacteria and enterococci. According to the report, the two samples of the second worst class were taken in Birs am Birsköpfli and in the meadow on Weilstrasse. Swimmers should not dive there and thoroughly shower after bathing.
As in the previous year, no samples were assigned to the worst class, with the laboratory discourage Baden. The canton laboratory, however, points out in the report that sampling only results in snapshots. The samples are also taken at the time of a stable multiple days with good weather.
UV rays kill bacteria
According to the Cantonal Laboratory, it can generally be said that longer periods of good weather with intensive solar radiation have a positive effect on water quality: bacteria are killed by the UV rays of sunlight. On the other hand, after heavy rainfall the quality decreases as the riverbed becomes more turbulent and more material enters the water from the outside.
Longing for a bath in the Rhine? This is also the official Rheinschwimmen in mid-August. (Video: 20 minutes)