The City of Winnipeg's North End Sewage Treatment Plant, one of Canada's oldest oxygen wastewater treatment plants, is upgrading to an advanced biological nutrient removal and recovery facility. But not right away.
An RFP for the upgrade will be issued in 2019, said Geoff Patton, engineering manager in Winnipeg's water and waste department.
"Construction is expected to begin late that year, with completion expected three or four years after that," said Patton.
The current North End facility, which turns 80 this year, serves 70 per cent of the city's population and treats 200 million litres of wastewater per day.
Upgrades to the centre, which is the largest of the city's three sewage treatment plants, were ordered by the Province of Manitoba in 2003 after a spill of untreated, unfiltered sewage into the nearby Red River.
The $800-million project involves building two new facilities at the existing sewage treatment plant.
When completed, the upgrade will include new headworks, a wet weather treatment system and a biological nutrient removal process with phosphorus recovery and an upgraded ultraviolet disinfection of final effluent.
One facility will dispose of biosolids (partly treated solid waste) that are produced by all three of the city's sewage plants.
The other plant will remove phosphorus and nitrogen from liquid effluent.
At present these nutrients enter the nearby Red River, which carries them 25 miles north to Lake Winnipeg.
Lake Winnipeg is much appreciated by Manitobans for its recreation opportunities as well as its valuable commercial fishery.
The province also instructed the city to undertake upgrades at the West End and South End sewage plants.
The West End pollution control centre has already been completed. The fourth phase of the South End centre will start later in 2017.
The North End facility is being upgraded because it is old and needs to be expanded, said Councillor Brian Mayes, chairman of Winnipeg's standing policy committee on water and waste, riverbank management and the environment.
"Winnipeg has grown and expanded greatly since the original treatment facility was built," he said. "And there have been changes in provincial regulations and technical requirements."
Mayes said there are several reasons for the project's delay.
One is the massive nature of the project.
"The North End pollution control centre will be the biggest capital project Winnipeg has ever undertaken," he said.
There has also been a delay in getting all the necessary technical know-how together.
In addition, Winnipeg has been awaiting direction from the Ministry of Sustainable Development of the Progressive Conservative government, which succeeded the former New Democrat administration in April 2016.
"But once the new facility is completed, there will be benefits both in terms of greater capacity, as Winnipeg continues to grow, and in terms of better treatment of discharge, which ultimately ends up in Lake Winnipeg," Mayes said.
The lake is suffering from excess phosphorus loading, explained Alexis Kanu, executive director of the Lake Winnipeg Foundation.
"There are many sources of phosphorus in the lake," Kanu said. "They can include human and animal waste, agricultural fertilizers, runoff from streets and the excess flow of the spring melt."
The excess phosphorus promotes the growth of algae, which can form large blooms on Lake Winnipeg that are visible from space.
"The algae blooms are always a nuisance and sometimes toxic too," Kanu said.
When algae dies, it uses oxygen from the lake, which can kill the fish and other wildlife that depend on oxygenated water.
Kanu said Lake Winnipeg is the "canary in the coal mine" for the watershed that lies between the Rockies and the western end of Lake Superior.
"The health of Lake Winnipeg can affect the health of the whole watershed," Kanu said.
Although the North End treatment centre is a key part of the solution to Lake Winnipeg's phosphorus problem, it's no silver bullet.
"There are many smaller sources of pollution in southern Manitoba that need to be addressed," Kanu said. "But it's economical to focus on large sources, such as the North End facility."
Pollution control is such a challenging problem that many new technologies have been developed and more are under development now, said Arman Vahedi, professor of civil engineering technology at Red River College in Winnipeg.
"Some work better than others," he said. "The outcome depends on the specifics of what's in the wastewater and the amount of electricity the technology requires. Some technologies can be very expensive."