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Wastewater Treatment

The City’s Wastewater Treatment Section consists of six major pumping stations and one state-of-the-art Wastewater Treatment Facility (WwTF).

Wastewater is the mixture of liquid and solid materials that residents and businesses flush down toilets and empty down sinks and drains. This material is directed to the plant through a network of pipes that make up the City’s sanitary sewer system to the WwTF. Treating wastewater is a process of cleaning it to remove solids, chemicals and other undesirable material before it is pumped to Lake Simcoe.

Province-wide COVID-19 Wastewater Surveillance Initiative

The City joined the province-wide COVID-19 wastewater surveillance initiative and is providing samples from the WwTF to labs that run analysis to determine the amount of COVID-19 present. Read more about wastewater surveillance:

Wastewater Treatment Facility (WwTF)

The City currently is undertaking a project to retrofit a portion of the WwTF to meet new Provincial regulations.

The WwTF is a tertiary treatment plant that uses ultra violet disinfection to treat all sewage before sending it into Lake Simcoe. The facility receives domestic, commercial and industrial wastewater and provides a level of treatment to meet the water quality standards of Lake Simcoe. Overall, the entire treatment process can be described at the transformation of wastewater into three useful products:

  1. Treated effluent
  2. An agricultural crop fertilization supplement
  3. Energy, in the form of heat and electricity


The City maintains high standards in wastewater treatment to ensure there is minimum effect on Lake Simcoe. An in-house laboratory, located within the WwTF administration building, allows for constant monitoring of all processes within the WwTF to ensure standards are being maintained. It provides analysis and support for the Environmental Services branch including WwTF Operations and Environmental Response and Investigation. Analysis performed routinely include, but are not limited to; Ammonia, Phosphorus, pH, Turbidity, Solids analysis and Biological Oxygen Demand. The immediate availability of results aids in plant performance evaluation and compliance assurance of the plant’s discharge with the Ministry guidelines. Internal quality and assurance control are equivalent to those set out by regulatory authorities.


WwTF Frequently Asked Questions
What is the flare coming from the stack at the WwTF?

Excess bio gas (a natural bi-product of sewage treatment) is being burnt off. This is a normal process at the WwTF.

What is the City doing about odour control at the Wastewater Treatment Facility on the lakeshore? 

Odour is always on our radar and we are continually trying to improve by adopting new technologies, such as Biotower odour control technology which uses fewer chemicals, emits less carbon dioxide and is better for our environment. 

Here are some odour-control technologies that have been recently implemented at the Wastewater Treatment Facility:

  • Summer 2017: facility upgrades including improved odour control equipment at the sludge loading area and a new wind direction/velocity monitoring system at the odour sampling station. 
  • Fall 2016: new bar screens and a waste compactor complete with new odour control devices were installed. The bar screens improve the quality of biosolids and the reliability of pump operations in the Wastewater Treatment Facility. 
  • Summer 2016: New Cairsens continuous air monitoring stations installed to continuously monitor for two groups of odourous compounds: Total Reduced Sulphur (TRS) and Volatile Organic Compounds (VOC). This technology will help improve our awareness and address public concerns as they arise.  

Although no process is 100% effective, these updates have significantly improved odour control.

Sewage plant odour control is a complicated subject with many technical training colleges and universities offering dedicated air pollution control courses. The ease of removing odour depends on many factors including the cause of the odour and the technology available to remove it. 

Why do we want to treat wastewater?

Treatment of wastewater is an essential process that prevents contamination and the destruction of our waterways, drinking water resources and natural water resources. Wastewater is approximately ninety-nine percent water and only one percent solids. The removal of these solids and disinfection of the water before discharge is the basic concept of wastewater treatment.

If wastewater was discharged without treatment directly to a receiving water system, such as Kempenfelt Bay, it would severely damage the water quality and render it unsuitable for swimming, fishing and other recreational activities.

Wastewater is a carrier of harmful bacteria and micro-organisms known as pathogens. Several pathogens include Cryptosporidium, Salmonella, Typhoid, E-Coli, Hepatitis A & B and Giardiasis also known as “beaver fever”.

Wastewater is also rich in nitrogen and phosphorus nutrients which stimulate excessive aquatic growth, which in turn, can be detrimental to aquatic life such as fish and waterfowl.

How do we evaluate wastewater?

Wastewater can be measured and evaluated in many different ways. Physical characteristics such as colour, odour and temperature are perhaps the most obvious to us. Two of the most important measurements that have a wide application in wastewater treatment are Suspended Solids and Biological Oxygen Demand.

Suspended solids refer to un-dissolved articulate matter which may be filtered from the liquid portion. Wastewater containing excessive amounts of suspended solids can cause turbidity providing protection for pathogens to live or blanketing of the lake bottom and, in turn, destroying spawning beds for aquatic life.

Biochemical Oxygen Demand, or B.O.D., represents the quantity of oxygen utilized in the stabilization of wastewater under controlled laboratory conditions. High values are indicative of the capacity of wastewater to cause rapid depletion of this dissolved oxygen content of a receiving body of water, rendering it incapable of sustaining higher life forms.

How does wastewater arrive at the WwTF?

The sanitary system is a series of pipes specially designed to transport the millions of litres of wastewater generated each day. Sewer piping is categorized by the type of flow it transports namely sanitary, storm and combined sewers. The City of Barrie system is constructed as a separated sanitary and separated storm sewer collection system. The sanitary system is directed to the WwTF. The storm system is direct to storm water management systems strategically located throughout the city.

The sewer system receives wastewater from the community and conveys it by gravity flow systems. Gravity flow sewer piping is laid with a slope steep enough to maintain a wastewater flow velocity of approximately 0.75 metres per second. This velocity is sufficient to keep all of the materials present suspended in its flow. In areas where it is geographically impossible to allow for gravity flow, lift stations are provided to receive wastewater from low lying areas and pumps are used to transport the wastewater for further transport by gravity sewers.

Wastewater Regulations

The City currently is undertaking a project to retrofit a portion of the WwTF to meet new Provincial regulations.

Environment Canada is the federal government agency responsible for environmental protection. Legislation in the form of the Environmental Protection Act provides overall direction for environmental protection in Canada.

Ontario’s Ministry of the Environment & Climate Change is responsible for environmental protection, including the provision of clean water through pollution control and prevention. The effluent from the WwTF is required to meet stringent limits established by the Ministry for discharge to receiving waters.

The City’s Environmental Investigation and Response Section is engaged in wastewater, stormwater and water quality management for the area which it serves. The Wastewater Operations Branch manages WwTF and the Oro Biosolids Storage Facility.

The City has enacted legislation specific to its wastewater operation in the form of the Sewer Use By-law. This By-law specifies the wastewater quality and quantity standards that must be met by wastewater generators who discharge to the City sewer collection and treatment system. The By-law establishes limits for various parameters to protect the WwTF.

The City continues to keep abreast of the best available technology in the treatment of wastewater. With good planning and selective growth, we look forward with confidence that Barrie and surrounding municipalities will always be able to enjoy the recreational water of Kempenfelt Bay while maintaining growth and prosperity in a healthy environment.


The City of Barrie has engaged the services of a Consulting Engineering firm to conduct a study that will evaluate alternatives for the optimization of biogas usage at the WwTF. See Biogas Utilization Study for details.

Sewage biosolids are nutrient-rich materials that result from the treatment of municipal wastewater. The City uses dual digestion to stabilize biosolids; once stabilized, they can be land applied in liquid form. Biosolids contain nitrogen, phosphorus and organic matter as well as essential micro-nutrients such as copper, iron, molybdenum and zinc, all of which are important to improve or maintain soil quality. When treated and processed, these residuals can be recycled and applied as fertilizer to improve and maintain productive soils and stimulate plant growth.

Biosolids Land Application

Land application of Biosolids is Provincially regulated under the Nutrient Management Act (NMA) and Environmental Protection Act (EPA).  All biosolids must meet legislated standards before they can be applied to fields. 

Biosolids recycling offers an environmentally sound management alternative to disposal, by reducing the amount of material that would otherwise go to the landfill or incineration. When applied according to best management practices, sewage biosolids will improve soil fertility and offset the need for commercial fertilizers. Biosolids also add organic matter to soil, enhancing soil structure, moisture retention and permeability; while reducing the potential for wind and water erosion. 

Benefits of Land Applying Biosolids

  • Improves soil quality and crop yields
  • Reduces the requirement for other fertilizers
  • Adds micronutrients and organic matter
  • Cost effectiveness for tax payers

Non-Agricultural Source Material Plan

Sewage biosolids are classified as a non-agricultural source material (NASM).  Regulations established in the Nutrient Management Act and Environmental Protection Act  for application of NASM include set back distances (e.g. from surface water, groundwater and residences), odour requirements, and land application requirements based on material quality. These requirements are included in a NASM Plan required for fields where sewage biosolids will be applied, not just to livestock farms.

The preparation of the NASM plan also takes into account maximum application rates, sampling and analysis results to determine an application rate that is both agronomically sound, and protective of the environment and human health. All NASM plans must be prepared by a certified NASM Plan Developer and approved by the Ontario Ministry of Agriculture Food and Rural Affairs.

Please contact the Environmental Operations at (705) 739-4221 for more information regarding application of Municipal Sewage Biosolids and developing a NASM Plan.

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