Biosolids

The COVID-19 virus does not remain viable in Ottawa’s biosolids, and can be safely applied to local farmland. Additional facts about COVID-19 in relation to land application of biosolids in Ontario is available from the Water Environment Association of Ontario.

Ottawa’s biosolids program continues to safely operate during the COVID-19 pandemic.  No health risks to workers or the public associated with this service have been identified.  Biosolids are available to farmers for application on farmland provided they follow Ontario’s Nutrient Management Act and Ottawa's Biosolids Best Management Practices that ensure all applications are reviewed and are protective of public health and the environment. Biosolids management is an important aspect of our wastewater treatment process, and will continue in compliance with all municipal, provincial and federal legislation and requirements.

The City of Ottawa Biosolids Beneficial Use Program is guided by the principles of the International Organisation for Standardization (ISO) No‘s 9001, 14001, and 18001, and is governed by Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA), the Environmental Protection Act and the Nutrient Management Act. It is also governed by the City's own policies and protocols.

The primary outlet of the Biosolids Beneficial Use Program is agricultural land application given the large agricultural land base surrounding Ottawa. This program is a major benefit to farmers as biosolids are provided free to farmers and the benefits last for several years.

What are the benefits of the program?

The City of Ottawa strives to beneficially reuse 100% of its biosolids. The benefits include:

Environmental benefits:

• Provides a nutrient rich soil conditioner that improves soil quality
• Facilitates plant growth
• Adds phosphorous to Ottawa area soils that are commonly phosphorous deficient
• Supports the three Rs program: reduce, reuse, recycle!
• Uses a renewable resource

Economic benefits:

• Increases crop yields and revenues for farmers
• Reduces the need for farmers to purchase expensive fertilizers every year as biosolid application can benefit soil conditions for up to 5 years
• Extends the life of our landfills – saving space and money

Social benefits:

• Supports local farming operations
• Supports the agricultural community as an integral part of Ottawa’s identity

The City of Ottawa’s Biosolids Beneficial Use Program Best Management Practices (BMPs) were developed based on the review of the literature, information gathered from interviews, and experience in the field.

The BMPs are a series of procedures designed to manage the Program in a manner that is consistent, transparent, and verifiable, and in excess of the Ontario Nutrient Management Act (2002) and Ontario Regulation 267/03.

The Beneficial Use Program is supported by the City of Ottawa's Sewer Use Program, which restricts what materials are permitted into the wastewater treatment plant and ensures that only treatable, non-hazardous substances enter the system and subsequently the biosolids.

Below is an abstract of the City’s best practices. The City’s BMPs are never less stringent than regulatory requirements. You can also view the complete City of Ottawa Biosolids Beneficial Use Program BMPs.

Leading by example: Award winning program

In 2012 the City of Ottawa was proud to win an award from the Water Environment Association of Ontario (WEAO) for “Excellence in Biosolids Management.” The City’s leadership in biosolids management is the result of two decades of work developing an exemplary program through implementing stringent and proactive best management practices (BMPs) and an Environmental Quality Management System (EQMS).

Staying current

City staff are active contributing members on numerous provincial and technical committees involving biosolids and stay current on issues and subjects important to overall biosolids management. A few of these include:

• Biosolids and Residuals Committee member of the Water Environment Association of Ontario (WEAO)
• Biosolids Committee member of the Canadian Waste Water Association (CWWA)
• International Standards Organization (ISO) Technical Committee 275, Sludge recovery, recycling, treatment and disposal: Land Application Working Group 4

If you have comments or questions regarding the City of Ottawa’s Biosolids Beneficial Use Program or would like to have biosolids applied to your farm land, please contact the City of Ottawa by email at biosolids-biosolides@ottawa.ca.

Ontario Ministry of Agriculture and Food

For more information on provincial regulations regarding biosolids management, land application, storage, permits or plans please contact the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) by telephone at the Nutrient Management Information Line, 1-866-242-4460, or by email at nman.omafra@ontario.ca.

Ontario Ministry of the Environment

For biosolids environmental incidents, spills, or legislative requirements, contact the Ontario Ministry of the Environment, Conservation and Parks by telephone at 1-800-565-4923.

Additional resources

• Biosolids video: To watch an informative video on biosolids please visit the Water Environment Association of Ontario (WEAO)
• Canadian Council of Ministers of the Environment (CCME)
• Canada-Wide Approach for the Management of Wastewater Biosolids
• OMAFRA Nutrient Management
• Water Environment Research Foundation (WERF)
• North East Biosolids and Residuals Association (NEBRA)

100% of Ottawa’s biosolids were beneficially reused in 2023, as described in the following table.

2023 Biosolids distribution map [ 1.34 MB ]

City of Ottawa biosolids are tested every two weeks by a third-party accredited laboratory for metals, pathogens and nutrients, as well as additional testing beyond regulatory requirements. The tests consistently demonstrate that both the metal and pathogen levels of the City’s biosolids are well below regulated levels. Based on the Ontario Regulation 267/03 of the Nutrient Management Act, 2002, the City’s biosolids are Category 3 biosolids suitable for agricultural land application.

The four most recent biosolids laboratory results are published regularly. Note that all the listed parameters are well below the provincial standards.

What are biosolids?

Biosolids are a product of sewage treatment that can be used as a natural fertilizer as well as a conditioner to recover contaminated or unusable soil. 

As sewage moves through Ottawa’s wastewater treatment facility, solids are extracted from liquids for further treatment. These solids are then dewatered to produce a dry, dark, nutrient-rich material called biosolid cake that closely resembles damp organic soil.

Ottawa biosolids are rich in essential nutrients for plant growth, such as phosphorous. Ottawa-area soils are naturally deficient in phosphorous and the application of biosolids helps return this essential nutrient to the soil.

Who benefits from the use of biosolids?

Farmers: 

• The City of Ottawa supplies, delivers and applies biosolids free of charge to eligible farms. This is a significant cost savings for farmers who would otherwise need to purchase commercial fertilizers. 
• If you are a farmer interested in participating in the City of Ottawa's Biosolids Beneficial Use Program, please send an email to biosolids-biosolides@ottawa.ca.

Residents:

• The reuse of biosolids keeps close to 50,000 metric tonnes of biosolids out of landfills every year. This extends the life of the City landfill and is more cost-effective than other disposal methods such as incineration.

How are biosolids typically used?

As a fertilizer:

• Ottawa biosolids are an excellent soil amendment providing a significant source of nutrients essential for plant growth such as phosphorus, nitrogen, calcium and other micro-elements. Using biosolids as a soil amendment on farm land is an effective and efficient way to increase the productivity of local soils. 

For land reclamation:

• Biosolids can be applied to remediation sites where the material improves soil structure, provides organics and nutrients needed for plant re-growth and helps with water retention.

Do biosolids contain metals?

Yes. However, the levels are closely monitored and are well below provincial regulation limits. Also, under the Nutrient Management Act, the City is required to monitor and report to the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA). Some metals such as copper are considered essential trace elements for plant growth. 

The City of Ottawa operates a variety of programs to minimize contaminants entering the wastewater stream, including:

• The Sewer Use By-law 
• The Sewer Use Program for industrial waste
• The Household Hazardous Waste program
• Waste Explorer

Is land application of biosolids a common practice?

Land application of biosolids is a common and acceptable practice for many North American municipalities. Ottawa has had a biosolid land application program since 1992.

What kinds of crops are fertilized with biosolids?

Ottawa’s biosolids are typically used to fertilize crops that are used for fuel or undergo further processing prior to animal consumption, such as:

• field corn
• cereal crops (e.g. wheat)
• legumes (e.g. alfalfa and soybeans)

How often can biosolids be applied to farmland and how much?

The frequency of land applications varies from site to site. Several factors are considered when determining a suitable site for land application. Some of the factors include: proximity to residential areas, slope of the land, soil chemistry, drainage, crops to be grown, and nearby watercourses. Ontario Regulation 267/03 restricts the volume of biosolids that can be applied to a field to protect both surface water and ground water in Ontario.

Do biosolids have an odour?

Yes, and the City employs the following best management practices to minimize odour during land application:

• Biosolids must be incorporated into the soil within 2 hours of their application
• Stockpiling of biosolids in fields is not permitted
• Local residents within 450m of the spreading location are notified a few weeks before the biosolids are applied
• Biosolids are not spread on Sundays or statutory holidays

What does the City do to assess my water quality? 

As per the City of Ottawa’s best management practices, the City offers free well water testing upon request to households adjacent to biosolid application sites. Tests will be taken up to four weeks before biosolids are applied, and between 10 and 12 weeks after application. All well test results are provided to the well owner.

Interested residents may book free well testing by calling 1-877-360-3830 or 613-260-3830. Residents may also request testing through email at biosolids_biosolides@ottawa.ca.

Ottawa Public Health provides free well testing to all well owners.

Why does the City apply biosolids instead of putting them in a landfill?

Land application is currently the most sustainable and cost-effective reuse option for the City of Ottawa’s biosolids. In addition, land application takes best advantage of a fixed and limited resource – phosphorus – which is essential for plant growth. Land application of biosolids redirects 50,000 metric tonnes towards beneficial reuse of material and puts valuable nutrients back into the soil.