EESA06H3 Lecture Notes - Lecture 9: Leachate, Keele Valley Landfill, Night Soil
10 May 2018
School
Department
Course
Professor
Landfill: The Artificial Landscape
- Modify landscape using waste materials as ‘fill’
- Was limited to disposal of ‘night soil’ and ash from houses
- Natural gradient of river destroyed
- Required constant dredging
- Volume of sediment removed reflects various phases of urban construction in
watershed
- Sediments are contaminated
- ‘Disposed’ in special containment cells
- 50% downtown Toronto is landfill
- First Toronto map 1912
- Downtown area underline by Iroquois sands and gravels
- Abandoned pits and quarries prime sites for ‘reclamation’
- Infilled with industrial and residential waste
- 1970-1990 was ‘out of sight, out of mind’
- Liquid and solid waste simply dumped in the ground
- Large hills created above natural landscape
- Percolation of rainwater down waste creates ‘leachate’
- Contaminates surrounding ground water and maybe surface rivers
- Landfills now have ‘liners’ at their base
- Collects and treats leachate
- Legacy of old ‘sanitary’ landfills remain
- Vertical joints and gravel beds act as ‘hydraulic windows’
- Allow leachate to pass through till into underlying aquifers
- Methane gas produced at landfills produce electricity
- Northern Till is a 50 m layer across southern Ontario
- Thought to be suitable foundation for waste dumps
- Water easily penetrates till through joints and sand beds
- Largest municipal landfill in Canada is Toronto’s Keele Valley site
Document Summary
Modify landscape using waste materials as fill". Was limited to disposal of night soil" and ash from houses. Volume of sediment removed reflects various phases of urban construction in watershed. Downtown area underline by iroquois sands and gravels. Abandoned pits and quarries prime sites for reclamation". 1970-1990 was out of sight, out of mind". Liquid and solid waste simply dumped in the ground. Percolation of rainwater down waste creates leachate". Contaminates surrounding ground water and maybe surface rivers. Landfills now have liners" at their base. Vertical joints and gravel beds act as hydraulic windows". Allow leachate to pass through till into underlying aquifers. Methane gas produced at landfills produce electricity. Northern till is a 50 m layer across southern ontario. Thought to be suitable foundation for waste dumps. Water easily penetrates till through joints and sand beds.
