Sewage discharge as a result of the construction work means that the outdoor swimming area must be temporarily closed, newspaper Aftenposten reports.
Any discharge will be restricted to occurring during Wednesday night, provided that weather conditions are correct and the correct equipment is in place, according to the report.
Closure of the outdoor pool could last from a few hours to two days.
“The Oslo Municipality Water and Sewage Administration is very sure that it will be able to prevent the discharge from getting into the river and out into the fjord,” Richard Kongsteien, head of communication with Oslo Municipality's urban environment agency, told Aftenposten.
Municipal authorities had initially not expected warning against bathing to be necessary, Kongsteien confirmed.
“It has been a little back and forth. But we have now made an assessment and have decided to close the outdoor pool,” he said.
The leakage will occur as a result of safety measures being taken in connection with the excavation of the Follo Line tunnel under a discharge tunnel.
The Water and Sewage Administration will place barriers near the discharge at the Alna district in Oslo in order to collect refuse that escapes with the leaked material, but cannot guarantee that everything will be contained, Aftenposten reports.
Wind and tidal conditions will be important factors in determining how much contamination escapes into the Oslo Fjord. As such, the municipality wishes to take precautionary measures.
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