Protecting our waterways

Nutrients in wastewater, such as phosphorus and nitrogen, can act as a food source for algae, fish, and other animals. If a river or lake receives too many nutrients, it can lead to overgrowth of algae, which hurts the biodiversity and overall health of the water system.

The City of Winnipeg is committed to reducing the amount of nutrients we release to our rivers and lakes, including Lake Winnipeg, which currently suffers from high phosphorus levels.

Lake Winnipeg

The City of Winnipeg's sewage treatment plants currently account for four per cent of the phosphorus loading to Lake Winnipeg each year, according to data from the State of Lake Winnipeg Report.

Phosphorus graph

Phosphorus levels from the City's sewage treatment plants have been decreasing over the past ten years. Upgrades to the West End Sewage Treatment Plant (also known as the West End Water Pollution Control Centre, or WEWPCC) and North End Sewage Treatment Plant (also known as the North End Water Pollution Control Centre, or NEWPCC) have resulted in less phosphorus entering Lake Winnipeg. When the South End Sewage Treatment Plant (also known as the South End Water Pollution Control Centre, or SEWPCC) upgrade is finished these levels will go down even further.

Lake Winnipeg has a very large watershed that receives drainage from Alberta, Saskatchewan, Manitoba, north west Ontario, North Dakota, South Dakota, Montana and north west Minnesota. The drainage area is approximately 1 million square kilometers, or 1.5 times the size of Manitoba. Lake Winnipeg has the largest ratio of drainage area to lake surface area in the world, according to a report from Environment and Climate Change Canada.

Lake Winnipeg watershed map

Credit: Environment Canada

What the City is doing

The City of Winnipeg has been doing our part to reduce nutrient loading to our rivers and lakes for over 10 years. We have been upgrading our infrastructure and researching and testing interim options to remove phosphorus from wastewater. We are also proud to support environmental protection research and environmental groups that work to protect Lake Winnipeg, including the Lake Winnipeg Research Consortium.

Sewage treatment plant upgrades

WEWPCC and NEWPCC were upgraded in 2008 and 2009, respectively. These upgrades reduced the phosphorus load from Winnipeg's sewage treatment plants to Lake Winnipeg, by 20 to 25 percent.

Ongoing upgrades to SEWPCC and additional planned upgrades to NEWPCC will reduce this number even further, once these projects are completed.

The remaining upgrades to NEWPCC and SEWPCC will reduce the amount of nutrients being released into our waterways, but will take years to complete. In the meantime, the City has been studying alternative options to remove phosphorus from our wastewater, including a recent proposal from the International Institute of Sustainable Development (IISD) and the Lake Winnipeg Foundation (LWF).

In 2020, the City tested interim solutions for removing phosphorus. Testing is important because the City's sewage treatment system was never designed or engineered to work with this level of chemicals. The bacteria that work to treat the sludge may get sick because of the chemical byproducts that are made.

Interim solutions needed to be tested to ensure the process would work during all four seasons, as changing weather patterns and seasons can have different impacts on the amount of byproducts, like sludge, that are made. Results indicated that some interim phosphorous removal is possible, but not during high flow periods (e.g. spring flood).

December 2019

The Manitoba Government responds to the City’s Notice of Alteration.

February 2020

Consultant selected to start testing interim solutions for removing phosphorus (chemicallytreatment, and Alternatives 2 and 6 outlined in the City of Winnipeg Request for a 'Notice of Alteration' for the North End Sewage Treatment Plant Environment Act Licence No. 2684RRR report).

December 2020

A summary report of interim phosphorous options was completed and submitted to the Province. It included recommendations based on computer modeling and laboratory tests, contains preliminary estimates for costs, and a proposed schedule. The preliminary recommendations will be used for regulatory review and budget approvals. Further testing and analysis will still be required in Spring 2021 to capture the spring high flow period.

March/April 2021

The Interim phosphorous removal study will complete laboratory testing based on spring high flows to validate computer modeling for the high flow season. It is not anticipated to significantly alter the conclusions or recommendations of the December 2020 summary report but may indicate if some interim phosphorous removal can be achieved in high flow periods.

April - September 2021

A constructability review will determine if the NEWPCC Upgrade Schedule can be accelerated. The schedule currently shows the Upgrade being completed in 2032; the review will examine aspects of construction such as laydown areas, traffic flow, seasonality impacts etc.

June 2021

Final test results presented to the Standing Policy Committee on Water and Waste, Riverbank Management and the Environment.

December 2021

Construction and commissioning of the SEWPCC Biological Nutrient Removal Upgrade completed. This step is required before implementation of any interim phosphorus removal at NEWPCC to ensure the process is compatible with the added SEWPCC sludge expected from the completion of this upgrade.

August 2023

Interim solution for removing phosphorus implemented at NEWPCC, subject to Provincial approval and a final construction schedule.

The City of Winnipeg's Water and Waste Department supports initiatives to improve water quality and wastewater treatment with the following grants and memberships:

Save Our Seine

Annual $30,000 grant to the Save our Seine advocacy group to promote environmental protection and stewardship of the Seine River.

For more information on Save our Seine:

University of Manitoba Collaborative Research

Annual $30,000 grant and services-in-kind to support research into new and innovative wastewater treatment processes, with an emphasis on improving treatment efficiency and nutrient removal.

Lake Winnipeg Research Consortium

The Water and Waste Department is a supporting member ($60,000) of the Lake Winnipeg Research Consortium. The Consortium promotes research and understanding on issues critical to the health and wellbeing of Lake Winnipeg.

For more information on the Lake Winnipeg Research Consortium:

What residents can do

Things that go into the sewer through toilets, sinks, or storm drains can clog our sewer system or end up in our rivers. You can help make a difference in the health of our waterways by switching to phosphate-free soaps and detergents and following these proper disposal suggestions.

Don't flush garbage down the drain

Put the following items in the garbage where they belong, instead of down the drain:

  • Cigarette butts
  • Dental floss
  • Condoms
  • Rags
  • Tampons and tampon applicators
  • Sanitary napkins
  • Disposable diapers
  • Human and pet hair
  • Cotton swabs
  • Cosmetics/makeup
  • Wipes (pre-moistened personal hygiene towelettes, often advertised and labelled as flushable or biodegradable)
  • Food scraps (an even better solution is to compost them or dig them into your garden)
  • Vegetable and animal grease, fats, oils (these substances can clog the sewer in your home and the City system and cause sewer backup)

Anything on the ground can wash into the storm drains on streets and lanes and end up in the rivers, so:

  • Clean up your pet waste.
  • Check your vehicle regularly to make sure hazardous waste fluids, such as oil, antifreeze and gasoline, aren't leaking.
  • Don't litter.
  • Don't put grass clippings, leaves and other yard waste on the streets or into rivers – not only do they add harmful chemicals and nutrients to the rivers and clog storm drains, it's against Sewer By-law 106/2018.

Hazardous waste, chemicals and prescriptions drugs are potentially dangerous and don't belong in the garbage or dumped down the drain – they need special handling.

  • Dispose of hazardous waste products safely by taking them to a 4R Winnipeg Depot or a Waste Wise eco depot.
    • These danger symbols can help you identify many hazardous waste products – e.g., corrosive, explosive, poison and flammable
      HHW symbols
  • Many chemicals can damage the sewer in your home and the City's sewer system. Our wastewater treatment plants may not be able to remove them and they can end up in the river, harming fish and other aquatic life.
  • Take leftover or expired prescription drugs and over-the-counter medicines to a pharmacy or Waste Wise eco depot where they will be disposed of safely.


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What are nitrogen and phosphorus?

Nitrogen and phosphorus are essential components of a healthy ecosystem. Virtually all human activities can introduce new sources of these nutrients to waterways.

What is nutrient loading?

Nutrient loading is the release of nitrogen and phosphorus into the environment.

Where does the phosphorus that is released into Lake Winnipeg come from?

Phosphorus released into Lake Winnipeg comes from a variety of sources, including untreated wastewater and run-off from fertilized agricultural fields. More than half of the phosphorus released to Lake Winnipeg comes from outside of Manitoba, as Lake Winnipeg has a very large watershed that receives drainage from Alberta, Saskatchewan, Manitoba, north west Ontario, North Dakota, South Dakota, Montana and north west Minnesota.

Why is it important to reduce nutrient loading in our rivers and lakes?

High levels of nutrients in Lake Winnipeg, like phosphorus and nitrogen, cause excessive algae and weed growth. This lowers water quality, harms fish and other aquatic life as a result of lower oxygen levels, and affects the appearance and recreational enjoyment of our rivers and lakes.

How does sewage treatment work?

Our sewer systems collect wastewater from industry, commercial businesses, and homes. From there, it is sent to one of our three sewage treatment plants to remove the major contaminants (carbon, nitrogen, and phosphorus) and harmful bacteria, such as E. coli.

To remove the contaminants, we send the raw sewage through several processes in our plants. Bacteria play a major role in the treatment process. The activated bacteria use the contaminants in the sewage as food to reproduce. Once this treatment cycle is completed, the bacteria are removed, the treated water is disinfected, and it is sent to the river.

What is sludge?

Sludge is a solid byproduct of wastewater treatment. During the wastewater treatment process, the solid sludge is separated from the liquid wastewater. The sludge consists mainly of organic matter and is further treated and dewatered. After treatment, the sludge is called biosolids, which can then be used in our biosolids land application program, as a compost, or in landfill reclamation.

Can the City use ferric chloride or other chemicals to reduce phosphorus loading from NEWPCC?

The City currently uses ferric chloride to remove phosphorus from its sludge treatment system at NEWPCC, where sludge from all three sewage treatment plants is treated. Recent proposals have suggested adding more of the chemicals to increase phosphorus removal. This must be studied further as using too much of ferric chloride may kill off the bacteria that is used to treat the sludge. Too much chemical use may also make more sludge than the plant has the capacity to treat. If the plant produces too much sludge, there is a risk of partially treated sewage entering our waterways.

Are there any other interim solutions to reduce phosphorus loading prior to the completion of upgrades at the NEWPCC?

Multiple interim solutions for reducing phosphorus loading at NEWPCC are outlined in the City of Winnipeg Request for a ‘Notice of Alteration’ for the North End Sewage Treatment Plant Environment Act Licence No. 2684RRR report. The City tested some of these solutions in 2020. The results have been submitted to the Province for regulatory review.

What steps has the City taken to reduce nutrient loading to Lake Winnipeg from its sewage treatment plants?

The City has been working towards reducing its nutrient loading to Lake Winnipeg for over 10 years by upgrading infrastructure, researching alternative options to remove phosphorus from wastewater and supporting research and environmental protection.

 Is there anything residents can do to reduce nutrient loading into our waterways?

Residents can help make a difference in the health of our waterways by switching to phosphate-free soaps and detergents and following proper disposal suggestions.

 What future steps will the City be taking to reduce nutrient loading to Lake Winnipeg?

The City will continue working on upgrading SEWPCC and NEWPCC to further reduce the amount of phosphorus released into our waterways from our sewage treatment plants.

In 2020, the City began testing interim solutions for removing phosphorus. Interim solutions will be tested for at least one year to ensure the process will work during all four seasons, as Winnipeg's weather can vary drastically depending on the season. A summary report was submitted to the Province in December 2020.

 Will the upgrades to Winnipeg's sewage treatment plants completely eliminate nutrient loading from the City's wastewater?

At the completion of the upgrades to WEWPCC, NEWPCC and SEWPCC, which are required to meet current Environment Act licence requirements, it is estimated that the City's sewage treatment plants will contribute approximately one to two per cent of the total nitrogen and phosphorus load to Lake Winnipeg.

 Will eliminating phosphorus loading from the City's sewage treatment plants completely restore Lake Winnipeg?

Reducing the City's phosphorus contribution from its sewage treatment plants will help Lake Winnipeg, but it is not enough to restore Lake Winnipeg completely or eliminate algae blooms. Lake Winnipeg receives nutrients from many other sources and these sources must also be reduced in order to restore the lake.

 What was Manitoba Conservation and Sustainable Development’s response to the City’s request for an extension to the compliance date?

Manitoba Conservation and Climate denied the request the City’s request for an extension. The City will work with Manitoba Conservation and Climate to prepare a new interim phosphorus reduction plan and a new plan for full licence compliance. Further details can be found here:


North End Sewage Treatment Plant (NEWPCC) Upgrade updates

City of Winnipeg Request for a 'Notice of Alteration' for the North End Sewage Treatment Plant Environment Act Licence No. 2684RRR

Province of Manitoba, Sustainable Development – Lake Winnipeg

Province of Manitoba, State of Lake Winnipeg Report

Province of Manitoba, Lake Winnipeg: Nutrients and Loads Status Report

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