1. Solid and Liquid Waste Management
Environmental Science 20

2. Sources of Solid Waste What is Solid Waste?
Solid Waste is any solid or semi-solid material that has been discarded
Each year, Canadians generate 30 million tonnes of. This is equivalent to the mass of 250 CN Towers
Waste Stream is the movement of waste from its source to its final destination.
Solid waste enters the waste stream from 3 major sources:
Agriculture
Industry
Municipalities

3. Agricultural Solid Waste
Farms, Ranches, Feedlots, and many Slaughterhouses are the sources of agricultural wastes.
Sources of Agricultural Waste:
Animal waste (Manure)
Organic Matter leftover after harvest
Fertilizer waste is often burned (air pollution)
Rainwater and irrigation run off
Livestock water may also carry microorganisms such as E. coli, that can harm human health

4. Industrial Solid Waste
Industrial solid waste may come from manufacturing, construction, mining, and other industries.
These wastes range from chemicals used in manufacturing to wastes produced during construction or demolition.
Mines produce mine tailings – particles left over after ores have been processed.
Some mines, such as Uranium mines produce hazardous waste which is difficult to dispose of safely.

5. Municipal Solid Waste
Municipal Solid Waste (MSW) includes al garbage – including things that can be recycled and composted – from homes, businesses and schools.
Canada is among the world leaders in the yearly production of MSW.
Each Canadian produces an average of 1030kg of waste per year.

6. Where does it go? Landfills
Landfills are disposal sites for solid waste where the waste is buried between layers of soil, filling in low lying ground.
Landfill provide some benefits to the environment:
Solution for solid waste management
Some landfill produce gases that can be used for electricity
Compactors are used to reduce the volume and of waste and therefore the size of the landfill. This also reduces the smell helping to limit insects and rodents.

7. How a Modern Landfill Works

8. Leachate and Landfill Gas
As water seeps down into the landfill, chemicals from garbage dissolve in it. The liquid that results is called leachate.
Leachate can pollute nearby soil and waterways if it leaves the landfill.
Modern landfills have rubber or clay liners to contain the leachate and prevent it from entering the surrounding ecosystem and drainage systems are installed to collect it.
Modern landfills are also built far from waterways to further minimize polluting of the ground water.
Landfill gas is created by bacteria as they break down the organic materials in the garbage. The gas is a mixture of methane and carbon dioxide (both greenhouse gases). Landfill gas is also flammable and explosive.
Technology can help manage landfill gas. Gas capture and combustion can be used to generate electricity to power homes and businesses.

9. City of Saskatoon Landfill
Saskatoon Light and Power – Green Power Initiatives
a/services- residents/power- water/saskatoon-light- power/clean-power- generation-initiatives
City of Saskatoon
a/services- residents/waste- recycling/landfill
Contaminated Groundwater Article:
/canada/saskatoon/cont aminated-groundwater- likely-leaking-from- saskatoon-landfill-into- river-opposition

10. Available Space About 80% of Canadian waste goes into landfills.
Public resistance comes from concern over water contamination, disease-carrying organisms, odors and truck traffic. The acronym NIMBY (not in my backyard) summarizes the public opinion.
The number of landfills has been declining:
Some do not meet regulations
Others have reached their capacities
Area with high population densities are challenged to find sites that are geologically suitable and there is opposition from people in the area

11. Where does it go? Thermal Treatment
Thermal Treatment is the processing of solid waste at high temperatures.
Reduces the volume of waste in landfills by 10-20%.
There are several types of Thermal Treatment:
Type
Process
End Products
Incineration
Complete combustion at temperatures over 850°C
CO2, H2O, ash, and other air pollutants
Pyrolysis
Thermally processed in oxygen at lower temperatures
Synthetic gas called syngas (mixture of gases which are pollutants)
Gasification
Thermally processed with limited oxygen, but enough for total combustion
Syngas and solid residue

12. Where does it go? Exportation
Densely populated areas may look to export their waste to other places.
Transporting solid waste to another region is expensive and many people believe that shipping wastes to distant places is unacceptable.

13. Liquid Waste Management
Wastewater is any waste that occurs in or can be changed to liquid form
Wastewater can come from many places:
Agricultural – wastewater from farms and feedlots can contaminate surface and ground water with run off from fertilizers and pesticides
Industrial – Sources include: petroleum products, metals, nutrients and sediments
Municipal – May come from homes, businesses, schools and urban surfaces. Waste water from these sources is often grouped under two headings:
Storm water
Sewage

14. Wastewater from Municipal Sources
Storm water includes rain and melting snow that drains from driveways, roofs, roads and other urban surfaces.
Sewage includes any materials that are rinsed down a drain or flushed down a toilet. Sewage may also contain:
Plasticizers
Medicines
Pesticides
Flame retardants

15. Treating Sewage – Septic Systems
Where land is available and populations are low, septic systems are an effective way to treat sewage.

16. Treating Sewage – Municipal Sewage
Cities and towns are linked to sanitary sewers. Sewage treatment follows 3 main steps:
Primary Treatment – physically separates large solids from sewage
Secondary Treatment – involves the biological breakdown of dissolved organic compounds
Tertiary Treatment – inorganic substances are removed (nitrates and phosphates)

18. Treating Storm Water
Sanitary sewers are often connected to storm sewers
These sewers are routed to treatment facilities rather than discharged into waterways
This plan works well in dry weather, but can get over loaded during storms. This can cause sewage backup
Potential problems:
Erodes stream banks
Increase sediment can harm aquatic life
Temperature changes in the water reduces dissolved oxygen

19. Questions
Read sections and answer the questions.