We are developing a Biosolids Master Plan (BMP) that will determine how we will manage our biosolids in an environmentally sound, sustainable and cost-effective manner, while meeting Provincial regulations.
Biosolids, more commonly called sewage sludge, is the nutrient-rich end-product of sewage treatment. It contains significant quantities of organic nitrogen and phosphorus, as well as trace amounts of minerals that are beneficial for plant growth. Biosolids also contain metals and other material that are quite often limited by regulation or licence.
At the sewage treatment plants, the solids are separated from the wastewater. These solids, which consist mainly of organic matter, are then treated and dewatered. At the end of the process, the solids become biosolids.
The City’s three sewage treatment plants produced about 13,500 dry tonnes of biosolids in 2012. This is expected to increase to 23,000 dry tonnes by 2037.
Biosolids are provincially regulated, which includes production, transport, use (including beneficial use) and disposal.
Up until January 1, 2011, we would deliver, spread and incorporate a portion of our biosolids into agricultural land at no cost to landowners. The amount would vary depending on a number of factors (e.g., weather). For example, in 2010, we applied 48% of the biosolids on the land.
As a result of concerns about nutrient overloading in Lake Winnipeg, a Provincial regulation was enacted that prohibited the spreading of biosolids on land in winter, and decreased the loading rate of biosolids to farmland. Consequently, we have been landfilling biosolids at Brady Resource Management Facility (Brady Landfill).
We are also moving forward with a two-year, $7 million pilot program to compost biosolids at the Brady Resource Management Facility (Brady Landfill), which will be able to compost 20% of our biosolids. Depending on the results of the pilot, the composting option could be a long term solution for dealing with all or part of Winnipeg’s biosolids.
Developing a Master Plan
We issued a Request for Information for Biosolids Management (RFI) to identify groups and gauge the interest in the beneficial reuse of biosolids. This will help us understand the market and the financial implications for biosolids reuse.
Some potential beneficial reuse options for biosolids include:
- combustion with beneficial reuse (e.g., ash, energy capture)
- heat drying to form fertilizer-like pellets and applied to the land to utilize nutrients for agriculture, tree farms and land rehabilitation areas
- raw material for industrial processes (e.g., cement manufacturing, glass aggregate manufacturing, fertilizer manufacturing)
- applying to agricultural land meeting nutrient guidelines
|Jul – Oct 2013||Post RFI and hold information session|
|Nov – Dec 2013||Evaluate RFI responses and identify potential options|
|Early 2014||Obtain feedback through public participation|
|Jan – Sept 2014||Develop a Biosolids Master Plan|
|Oct 2014||Submit Biosolids Master Plan to the Province|