Immediate action required on algae

Opinion

Hey there, time traveller!
This article was published 22/07/2019 (1733 days ago), so information in it may no longer be current.

I have been enjoying the beauty of Lake Winnipeg since I was a boy. In recent years — and this is hardly a secret — the quality of the lake has steadily declined. One reason for this is the shocking irresponsibility of the City of Winnipeg.

Winnipeg’s North End Water Pollution Control Centre (NEWPCC) is the fourth-largest phosphorus polluter of all waste water treatment plants in Canada. It is also the single largest point source of phosphorus to Lake Winnipeg. Currently, the plant does not treat the city’s sewage for phosphorus removal — and as a result, it releases 600 kilograms of phosphorus into the Red River every day.

The nutrient phosphorus is the driver of algae blooms on Lake Winnipeg and other lakes throughout Canada. In excess, phosphorus contributes to the rapid growth of cyanobacteria, or blue-green algae, with impacts on the lake’s fisheries, recreation, tourism, drinking water supplies and aquatic food chains. As a lifetime summer resident on Lake Winnipeg, I have firsthand knowledge of the deleterious effect of algae blooms.

Winnipeg’s NEWPCC is a point source of phosphorus — it all comes discretely out of one pipe, instead of from diffuse, non-point sources across the landscape. Point sources of phosphorus tend to be easier to manage, because they are localized and infrastructure-based. Yet Winnipeg is still facing challenges and confusion when it comes to dealing with its North End plant.

The provincial operating licence for the NEWPCC sets a limit for phosphorus release: effluent from the plant is not to exceed 1 mg/L, by Dec. 31, 2019.

Unfortunately, Winnipeg is not meeting that limit — or that deadline. In 2017, phosphorus concentration in plant effluent averaged 3.5 mg/L. And according to the city’s most recently approved construction plans, phosphorus removal is not projected to be in place at the North End plant until at least 2035.

The good news is that cost-effective, technically feasible solutions for phosphorus removal exist. They have been in place for decades in jurisdictions around Lake Erie. In fact, these methods have been so effective that some eastern Canadian jurisdictions are now aiming for phosphorus limits of 0.3 mg/L. Winnipeg can — and must — follow suit.

The NEWPCC currently uses a chemical called ferric chloride, a type of iron salt. Ferric chloride is added at two points in biosolids treatment, in order to manage odour and keep pipes from clogging. It is not currently used as a phosphorus-removal agent.

By simply retrofitting existing NEWPCC infrastructure to add ferric chloride at the beginning of the treatment process instead of during biosolids treatment, Winnipeg could achieve a 70 per cent reduction in phosphorus loading from the plant. Modelled after the proven methods used in eastern Canada, this retrofit would remove an average of 426 kilograms of phosphorus per day from the plant’s effluent — enabling the NEWPCC to meet its 1 mg/L licence limit.

Such an interim retrofit is estimated to cost only $5 million to get up and running. This would be just a tiny percentage of the already-approved $400 million that the city plans to spend on upgrades to the plant’s power supply.

A retrofit would also allow the city to show progress in meeting the demand of the province that it have a clear plan for dealing with phosphorus. In January 2019, the province asked the city for “interim implementation options to expedite phosphorus removal” with the plan due to be submitted by the city this July.

The city has not yet, however, responded to the province’s explicit recognition that phosphorus needs to be removed immediately.

With a provincial election in the offing, all of Manitoba’s political parties will hopefully be seized with the importance of moving on phosphorus reduction in Lake Winnipeg. The city would be wise to anticipate this and move now in a cost-effective way.

The International Institute for Sustainable Development and the Lake Winnipeg Foundation have been advocating for city leaders to immediately implement such a retrofit solution in order to significantly reduce the phosphorus loading dumped into Lake Winnipeg. Both institutions have excellent research credentials, and they agree that in the short term, significant reductions in phosphate loading from waste water treatment can be achieved now.

It is time the City of Winnipeg took this advice. The very future of Lake Winnipeg depends upon it.

Thomas S. Axworthy is public policy chair at Massey College and is a longtime advisor to the Lake Winnipeg Foundation. He is the former president of the Gordon Foundation, a national body dedicated to the preservation of Canada’s freshwater resources.