Soil Fabrication Program

Introduction

The City of Winnipeg (City) is developing a soil fabrication program at Summit Landfill for use as landfill top cover. The soil fabrication program uses a mix of biosolids, woodchips, and street sweepings to produce soil that will help restore the landfill to a native prairie landscape. Following a successful pilot, the City plans to seek approval from provincial regulators in late 2020 to begin a long-term soil fabrication program in 2021.

We want Winnipeggers to learn about this waste diversion project that is creating a beautiful prairie area over a landfill and provide an opportunity to ask questions.

Background

The soil fabrication program is part of the multi-pronged approach developed as part of the City’s 2014 Biosolids Master Plan to beneficially use biosolids. The Biosolids Master Plan is a 30-year vision for how the City of Winnipeg will manage its biosolids in an environmentally sound, sustainable, and cost-effective manner, while meeting provincial regulations.

In 2018, the City began a three-year soil fabrication pilot project at Summit Landfill. The pilot program is exploring if soil fabrication is a long-term viable option to produce top cover at the Summit Landfill. The top cover will support vegetation growth and restore the landfill to a native prairie landscape. Some of the criteria that will help determine if the pilot program is successful include soil quality; vegetation growth; surface water, ground water, and odour impacts; winter viability; operational viability; and costs.

As the pilot program nears its end, the City is looking to transition the pilot program into a long-term operation and will seek provincial approval in fall 2020. The program requires an Environment Act Licence from the Province of Manitoba’s Environmental Approvals Branch.

The following components are being used to produce soil:

• Biosolids – a nutrient-rich, solid by-product of wastewater treatment
• Woodchips* – often from trees infected by Dutch Elm Disease and Emerald Ash Borer
• Street sweepings – screened sand and grit mix

*Woodchips from infected trees are created safely under a provincial permit and comply with regulatory requirements

The benefits of the soil fabrication are:

• Diverting biosolids, wood waste, and street sweepings from the landfill
• Providing a winter use for biosolids when composting and land application are not viable
• Providing a summer back-up use for biosolids if composting and land application are disrupted
• Completing the Summit Landfill cap that will reduce water infiltration, erosion, and greenhouse gas emissions
• Establishing native prairie habitat