University of Regina researchers have completed a 10 year study showing removal of nitrogen from Regina city wastewater discharge improves downstream water quality in Wascana Creek.

The study examined the effects of the 175 million dollar upgrade to the Regina wastewater treatment plant in 2016, which largely eliminated pollution with ammonia and reduced nitrogen by 85 percent.

The study is the first time scientists have shown nitrogen removal improves water quality.

Water quality has been affected by excess nutrients from cities, farms and other industrial activities, leading to algae blooms, biodiversity collapse and the activation of toxins and reducing oxygen levels.

The study shows removal of nitrogen from wastewater reduces abundance of algae and harmful cyanobacteria, while increasing beneficial species usually found in healthy water bodies.

The reports co-author, University of Regina biologist Dr. Peter Leavitt, says Regina wastewater in the past has been a cause of water quality degradation in downstream lakes of the Qu’Appelle Valley.

Now, he expects water quality to start to improve first in Pasqua Lake, then move east through the downstream ecosystems.

He hopes planned industrial activities don’t undo the good work.

Leavitt says full recovery of the Qu’Appelle lakes will likely take decades.

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