The Ministry of the Environment works with the Ministry of Agriculture, Food and Rural Affairs to ensure that the land application of sewage biosolids and pulp and paper biosolids is done in a manner that minimizes risks to the environment and public health.
Once treated and tested to ensure they meet regulatory requirements, the biosolids can be applied as a nutrient. Land application must follow strict provincial requirements. For more information on these requirements please see our Learn more section.
The nutrient cycle and soil fertility
Adding nutrients to agricultural lands by applying biosolids or manure completes the nutrient cycle. When nitrogen, phosphorus, organic matter as well essential micro-nutrients, such as copper, iron, molybdenum and zinc, are returned to the soil they help foster new plant growth.
Biosolids are a valuable nutrient source for growing field crops such as corn, soybeans, canola and cereals. Crops use the organic nitrogen and phosphorous found in biosolids very efficiently because these nutrients are released slowly throughout the growing season, allowing plants to absorb nutrients as they grow. Biosolids are also highly suitable for growing forage crops and for improving pasture.
Adding organic matter allows soil to breathe and hold more water which can decrease water runoff and soil erosion, and increase overall water conservation.
Ontario crops grown for human consumption are typically not fertilized with biosolids.
When biosolids are land applied they are limited to the agronomic rate and the waiting periods set out in Certificates of Approval and/or prescribed under the Nutrient Management Act.
Economic benefit
Using biosolids can reduce the need for commercial fertilizer and decrease production costs. Farmers can reduce costs by using sewage biosolids. They provide nitrogen, phosphorus and other micro-nutrients that would otherwise have to be purchased. At current fertilizer prices, farmers can save as much as $67 per acre using biosolids instead of commercial nitrogen, and $100 per acre using biosolids instead of commercial phosphorus. Many farmers receive biosolids from generators such as municipal sewage treatment plants, pulp and paper companies or food processors at no cost.
In addition, applying sewage biosolids to land is often less expensive than other management methods, such as disposal in a landfill, making it an attractive option for municipalities.