Advocates working to improve the health of Lake Winnipeg say they're frustrated that City of Winnipeg officials have rejected a proposed interim solution to slow the flow of phosphorus into the lake.

"Frankly, I think it's an embarrassing lack of leadership on the part of the City of Winnipeg," said Alexis Kanu, executive director of the Lake Winnipeg Foundation.

In March, the Lake Winnipeg Foundation and International Institute for Sustainable Development submitted a proposal to use a chemical called ferric chloride, which is already used in the treatment process, to reduce the levels of phosphorus flowing out of the city's North End water treatment plant.

The proposal was an interim solution while the city comes up with a plan to fully remove nutrients from the waste water, and works toward $1.8 billion in upgrades promised down the line.

The plant is one of the largest sources of nutrients flowing into Manitoba's biggest lake, feeding toxic blue-green algae blooms that coat beaches with slimy goo, kill plants and suck oxygen out of the water.

The province had set a deadline of Dec. 31, 2019, for the North End plant to meet nutrient reduction targets of one milligram per litre or less. The city had until July 31 to come up with a plan.

The North End plant treats 70 per cent of the city's waste. The foundation and institute estimate that using ferric chloride earlier in the process could reduce phosphorus discharge by 70 per cent.

On Tuesday, Tim Shank, acting director of the city's water and waste department, sent a letter to city council saying there was nothing the city could do in the interim to reduce phosphorus to the level set by the province.

The city has asked the province for new deadline of Dec. 31, 2021, to come up with a plan.

"Chemical phosphorus removal, such as described by the [Lake Winnipeg Foundation] proposal, generates an inert sludge that would put a significant sludge load on the city's system," Shank wrote in response to an email from Coun. Jeff Browaty asking for more explanation as to why the city rejected the proposal.

Sludge capacity

Kanu isn't convinced by the city's explanation for rejecting her organization's proposal. Other cities around the Great Lakes, including Toronto, Detroit, Brantford, Ont., and Pickering, Ont., have used the same method to reduce their phosphorus outputs, Kanu said.

"We know that our sludge management infrastructure right now at the North End plant is not operating at full capacity," she said.

The North End facility breaks down solid waste using microorganisms in large industrial devices called digesters.

"The current digesters which treat the sludge are at reduced volumes due to the need for ongoing maintenance," Kanu said.

Working with experts, the foundation calculated that using ferric chloride would lead to an 11 per cent increase in the amount of sludge produced.

The capacity of the North End plant can be increased to handle the additional sludge, said Coun. Browaty.

I think it's worth doing. So I'd like a better explanation of our staff as to why it can't happen. - Coun. Jeff Browaty, on the ferric chloride proposal

Currently, the city doesn't plan to implement full biological nutrient removal until 2031 and the estimated cost of upgrading the North End plant has grown to $1.8 billion. The estimated cost of the ferric chloride proposal is $3 million to implement and $2 million annually to maintain.

"I think it's worth doing. So I'd like a better explanation of our staff as to why it can't happen," Browaty said.

Cindy Gilroy, the chair of the city's water and waste committee, says the city isn't rejecting the proposal entirely, but it needs more time to make sure it can be implemented safely. The added chemicals could harm the bacteria that eat the waste, she said.

The extra two years the city has asked for would also give it time to assess how well the North End digestion system can handle additional sludge that will be produced by upgrades to the South End Water Pollution Control Centre, acting water and waste director Shanks said.

"If we can have more time to look into it, looking at the effects down the line, there might be some opportunity to add the different chemicals to be able to do this," Gilroy said.

The province says it is reviewing the city's request for an extension, as well as the information regarding interim options to reduce phosphorus outflows.

"In the meantime, all interim options must be fully considered and we expect the city to expedite these efforts as well as its work towards advancing a viable long-term solution," Sustainable Development Minister Rochelle Squires said in an email statement.

Councillor says there has been years of inaction on effluent despite ever-rising sewer and water rates. (Kristie Pearson)

Meanwhile, people living along the shore of Lake Winnipeg are watching as blue-green algae blooms arrive earlier in the year, Kanu said.

Although the Lake Winnipeg watershed is vast, covering multiple jurisdictions containing many dispersed sources of nutrients flowing into the system, the city is one of the rare single sources, contributing up to five per cent of the total nutrient load into the lake.

This presents an opportunity for the city to lead by example to help improve the health of Lake Winnipeg, said Dimple Roy, director of water management at the International Institute for Sustainable Development.

"It's a matter of will," Roy said.