Biosolids are the nutrient-rich, organic materials resulting from the treatment of sewage in a wastewater treatment facility (i.e. treated sewage sludge). They are a beneficial resource, containing essential plant nutrients, organic matter and are recycled as a fertilizer and soil amendment.

Biosolids are the solids that have come through the final stage of wastewater treatment, Solids Processing. The Ashbridges Bay and Highland Creek wastewater treatment plants process approximately 195,000 tonnes of biosolids each year.

The City’s biosoilds management can be categorized as follows:

  • Environmental:
    • Land application for agricultural and other uses
    • Pelletization to create fertilizer
    • Alkaline stabilization to create fertilizer product, landfill cover, or to increase the pH of acidic soil
  • Landfill
  • Incineration

Read more in the City’s Biosolids and Residuals Master Plan (BRMP).

Methods Used to Manage Biosolids