Biosolids management

If you are a farmer interested in participating in our program, please contact 1-877-360-3830 or 613-260-3830.

Biosolids are a by-product of wastewater treatment. The City has an objective to beneficially re-use 100% of the biosolids generated. The preferred alternative, because of its environmental benefits, is to use them in agriculture as a nutrient-rich soil-building material and fertilizer.

As sewage makes its way through the Robert O. Pickard Environmental Centre (ROPEC), solids are removed from the wastewater stream. Bacteriological processes are used to significantly reduce the solids as well as the amount of pathogens. The remaining solids are called biosolids.

Like soil, biosolids contain organic matter and nutrients such as nitrogen and phosphorus, which are essential for crop production and plant growth. They also contain traces of metals like iron and magnesium, bacteria and other micro-organisms. Still, approximately 70 per cent of the biosolids’ mass is water.  

Beneficial Use

In 2004, Council approved the application of biosolids on agricultural land. The land application program is carried out in accordance with provincial laws and regulations and the City’s Best Management Practices, established by the Medical Officer of Health. It includes third-party auditing of all activities.

Ottawa biosolids meet or exceed all provincial regulatory requirements. Their quality is monitored by an independent laboratory. On average, between 45,000 and 50,000 metric tons (mt) of biosolids are generated annually; as the city’s population is growing, this number is growing. The largest part is beneficially used. In 2011, 69 per cent was land applied, 19 per cent was used as landfill cover, and 12 per cent was landfilled.

The land application of biosolids is a safe, fiscally responsible and environmentally sustainable practice. 

  • It benefits taxpayers. Land application is more cost-effective than landfill. In addition less waste in the landfill extends the facility’s life span.
  • It benefits the environment. The soil within the Ottawa region is phosphorous deficient. Land application returns finite resources such as phosphorous to the soil. 
  • It benefits the farming community. Biosolids are a cheap, organic alternative to commercial fertilizers.


For more information on biosolids and the City's land application program, see our Frequently Asked Questions section. If you have comments or questions regarding the biosolids program, please call 613-580-2424, ext. 23257, or e-mail

Information on provincial regulations is provided on the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) website. You can also call the OMAFRA nutrient management information line at 1-866-242-4460, or e-mail

For additional OMAFRA Resources, see