Biosolids Disposal
Waste water in the City of Sault Ste. Marie is treated at two separate sewage treatment plants; the East End and West End plants. The biosolids or sludge that is generated at these plants is dewatered and transported to the City of Sault Ste. Marie landfill for disposal.
Historically approximately 10,000 tonnes of biosolids have been disposed of each year. The biosolids are approximately 25% solids and accounted for approximately 17% of the overall waste disposed of in 2013. The existing landfill is projected to have approximately 7.5 years of remaining disposal capacity (at the end of 2013).
This Study was initiated in 2008, a public open house was conducted in December 2008 and a final Draft report was prepared in September 2009. The study completion was subsequently deferred at the request of technology vendors to allow them to make presentations and submissions to the City regarding the capabilities of their respective technologies.
In addition, the province of Ontario introduced new compost standards in July 2012 which impacted the evaluation of one of the alternatives. The evaluations and report have been updated to reflect the passage of time.
The City initiated this project to address the following problems/opportunities:
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The diversion of biosolids from disposal would enhance the projected longevity of the existing landfill.
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There may be an opportunity to further mitigate odours in transporting and managing the biosolids.
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There are challenges in managing the biosolids at the landfill due to its poor workability and high liquid content. This problem has been exacerbated with the significant reduction in fibrous materials landfilled (ie: increased diversion of paper type products) and the disposal of commercial waste in other sites.
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There is a shortage of earthen cover materials available at the landfill to meet future operational needs.
Project Information