Biosolids Management

Biosolids Management

What are Biosolids?

Biosolids are the solids that result from municipal wastewater treatment and meet quality criteria outlined in the Ministry of Environment and Climate Change Strategy's Organic Matter Recycling Regulation. Because of their stabilized, nutrient-rich, and humus-like properties, biosolids provide a sustainable alternative to chemical fertilizers as a means to increase soil fertility where nutrients are limited and improve soil quality through the addition of organic matter.

Why Use Biosolids?

Biosolids contain nutrients, such as nitrogen and phosphorous, which are vital to healthy and productive soil. Biosolids also have a high organic matter content that improves soil quality, including allowing the soil to hold more water, thereby decreasing run-off and erosion. Biosolids that meet regulatory standards are suitable for use as fertilizer and soil amendments.

Fertilizing with biosolids returns nutrients to the land that might otherwise be lost. Using our biosolids in this way makes environmental and economic sense. The alternative to biosolids use is disposal in the Regional Landfill. With space declining at the Regional landfill, diverting biosolids from the landfill is consistent with the RDN's Zero Waste policy.

Since 1999, RDN biosolids have been beneficially used in agriculture, landfill closures, mine reclamation, and forest fertilization.

Health and the Environment

The production, distribution, storage, sale and use, or land application of biosolids are strictly regulated by the Organic Matter Recycling Regulation. Public health and the environment are protected in the management of biosolids:

  • The wastewater treatment process mimics the natural breakdown of wastes. When micro-organisms "digest" the solid material, they reduce volatile organics and pathogen concentrations.
  • We regularly test our biosolids to ensure they meet Ministry criteria for land application.
  • Biosolids land applications are restricted to:
    • Suitable forest stands
    • Suitable slopes
    • Suitable weather conditions (biosolids are not applied during heavy rain, over snow, or onto frozen ground).
  • Biosolids are not applied within specified setback distances from water bodies, property boundaries, and public roads.
  • Public access is restricted in the application areas through locked gates and signage.
  • Signage is posted at entry points and along select trails advising the public that biosolids are applied.
  • We monitor surface water across the biosolids application site.

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