The water quality of the Oulujoki River has deteriorated considerably over the past week. Whereas during winter haziness levels in the river are near zero, on Monday they measured a hefty 60 units. And data from a water quality monitoring buoy at the river’s mouth indicates that the haze levels are still rising.
The main culprit for the problem is snowmelt, which carries humus and other particulate matter from fields and forest ditches into the river. Also, flooding in tributaries such as the Muhosjoki River is adding to the haze problem in the main river.
This spring the situation is notably worse than in years past because of the exceptionally large snowfall the Oulu region experienced last winter, resulting in heavy snowmelts. Last spring there was less snow, and most of it evaporated.
Oulujoki is the primary source for the city’s drinking water and consumption needs. According to Jouni Lähdemäki, managing director of the Oulu Waterworks, this time of spring usually brings big challenges for water purification plants.
“We have to monitor the purification process more closely. The higher the levels are, the more we have to utilize chemicals in the process.”
According to Lähdemäki, the overall quality of the city’s drinking water should not be affected by the hazy waters in the river.
“We just have to work harder to meet the purity standards.”
The situation doesn’t usually return to normal until June because the heavy snowmelt will continue to affect the river until late May.