Biosolids

Biosolids management is recycling in its simplest form!

What are sewage biosolids?

Sewage biosolids are a byproduct of the municipal sewage treatment process. After entering a sewage treatment plant, sewage goes through a number of processes that reduce contaminants, leaving beneficial solids. The solids undergo additional treatment to:

• Reduce potentially harmful pathogens.
• Reduce potential odours.
• Convert complex organic substances into simple organic compounds.

The final treated product is known as sewage biosolids. The sewage biosolids are transferred to a storage facility until they can be used as a fertilizer on agricultural land under the provisions of Ontario Regulation 267/03.

Benefits of sewage biosolids

Applying sewage biosolids on agricultural land has benefited farmers for many years. Sewage Biosolids provide a valuable source of fertilizer and soil conditioning to farmers across the Region as they contain nutrients beneficial to plant growth:

• Phosphorus, nitrogen and sulphur (macro nutrients)
• Zinc, copper, selenium and magnesium (micro nutrients)

Sewage biosolids also contain organic matter which plays an important role in soil structure. Organic matter improves moisture retention, soil workability and enhances the absorption of nutrients and minerals.

Role of the Ministry of the Environment and Climate Change and the Ministry of Agriculture, Food and Rural Affairs

Before sewage biosolids are applied to agricultural land, the proposed site is evaluated against the following criteria:

• Soil fertility
• Soil texture
• Slope of land
• Crop nutrients requirement
• Site location
• Identification of groundwater wells
• Proximity to surface water

The selection process ensures the site chosen will benefit from the application of sewage biosolids, and not adversely affect the environment or public health. These agricultural sites must also be approved by the Ontario Ministry of Agriculture, Food and Rural Affairs and are subject to frequent inspections by the Ministry of the Environment and Climate Change's Agricultural Environmental Inspectors.

More information on the application of biosolids and the role of the Ontario Ministry of Agriculture, Food and Rural Affairs can be found on their website.