Investigation of green chemistry treatment options to address Chemicals of Mutual Concern in landfill leachate

(2023-2024)

Challenge

Landfills are the primary destination for solid waste in Canadian communities. While most waste remains onsite, rainfall percolates through it and creates a pollutant-rich liquid known as leachate. This leachate, laden with chemical and biological constituents, is either treated at the landfill or transported to municipal wastewater facilities.

The treatment efficacy for contaminants in wastewater across Canada is inconsistent and often limited. Consequently, the effluent discharged can pose risks to both ecosystems and public health. Moreover, advanced treatment does not address all known and unknown contaminants of concern. Upgrading wastewater treatment is expensive and lengthy for municipalities due to the slow adoption of new technologies, the long lifespan of infrastructure and the substantial financial investments required.

Despite this, there is a concerted effort by regulators and water managers to acquire more knowledge to mitigate the environmental and human health impacts of landfill leachate. To this end, Environment and Climate Change Canada has contracted CWN to conduct a study focusing on pre-treatment opportunities of Chemicals of Mutual Concern (CMCs) in landfill leachate while applying a green chemistry lens. For more information about CMCs, visit the Government of Canada’s webpage on reducing harmful chemicals.

Project

The objectives of this project are to:

1. Investigate the current state of green chemistry and green engineering as it pertains to the pre-treatment of landfill leachate before its acceptance for co-treatment at a wastewater treatment plant.
2. Create a searchable and sortable inventory of technologies that have the potential to effectively pre-treat landfill leachate while applying green chemistry or green engineering principles.

CWN did this by:

1. Obtaining insights from municipalities and water utilities, academia and technology companies on current practices related to monitoring and pre-treating landfill leachate and opportunities to use existing or emerging technologies to pre-treat landfill leachate.
2. Conducting a comprehensive literature scan that draws from Canadian and international resources to understand landfill leachate pre-treatment processes, and green chemistry or green engineering technologies to remove CMCs.

Outputs

This initiative aims to:

1. Support Environment and Climate Change Canada as it makes decisions on strategies to reduce CMCs in the Great Lakes Basin.
2. Raise awareness and advance knowledge among municipalities and water utilities on landfill leachate management considerations, pre-treatment technologies, and green chemistry/green engineering opportunities.
3. Support municipalities and other organizations in their endeavours to minimize the harmful effects of contaminants coming from landfills and wastewater treatment plants.