Cleaner wastewater makes for healthier rivers

Thursday, October 27, 2022
Helen Jarvie

Water Institute member Helen Jarvie, a professor of water and global environmental change in the Department of Geography and Environmental Management, recently shared research demonstrating how local investments in wastewater treatment are improving water quality, in an article published in the Journal of Environmental Quality.

Jarvie’s research explores the impacts of nutrients (phosphorus and nitrogen) from agriculture and wastewater, on water quality, including nuisance and harmful algal blooms (known as ‘eutrophication’).

Professor Jarvie and her collaborators, including fellow Water Institute member professor Merrin Macrae, used high-resolution in-situ sensor data to examine the impacts on the metabolism of the Grand River after the cities of Waterloo and Kitchener upgraded their wastewater treatment plants. Both cities discharge wastewater to the Grand River which is Canada’s largest river draining into Lake Erie. Over the last decade, the two cities have installed enhanced wastewater treatment processes, specifically nitrification, at their plants, reducing the amount of ammonia discharged to the Grand River.

“This is a great success story,” says Jarvie. “We have shown how investments in wastewater management have yielded important improvement to the ecological health and water quality of the Grand River.”

Improving our waterways will mean tackling all sources of excess nutrients. Jarvie emphasizes that wastewater is only part of the equation. “Agriculture is another very important contributor of nutrients to the Grand River, ultimately to Lake Erie and to other waterways.”

Listing Photo: Treated wastewater flowing into the Grand River from Waterloo, Ontario, in Canada. While treated wastewater reduces the threat for disease, it still releases nutrients into waterways that can impair aquatic ecosystems. Credit: Helen Jarvie