REGINA - A recently published study by Environment Canada says Regina's Wascana Creek is among the most polluted in the world.
Most of the creek's water contains treated sewage released by the city of Regina.
The study found concentrations of different kinds of nitrogen are way over the maximums set by the World Health Organization.
Peter Leavitt, a University of Regina biologist, says nitrogen levels in the water from the treatment plant are so high that it's toxic to fish.
He also says it's producing toxic algae in Pasqua Lake and some of the lakes in the Fishing Lakes chain.
The city is upgrading its treatment plant soon and Leavitt hopes it will look beyond the minimum requirements of the law and plan for the future.