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ADDIS ABABA SCIENCE & TECHNOLOGY UNIVERSITY
1. Hayleab tesfaye cde 0092/052. Lakew mengistu cde 0105/053. Dereje kuma cde 4. Kemal a/kadir cde5. Dereje seman cde6. Ayichew cde7. alemayehu
Effect of Landfill on the enviroment
ENGINEERING FOUNDATION ASSIGNMENT ON :-
Prepared By:
Class – A
Since there is a rapid increase in the average trash produced by a human being per day, it results in a huge amount of additive increase in trash at a international level.
Where Does our Trash Go?
31% Recycled69% Land filled
After recycling!
32%
14%12%
6%
9%
9%
6%
12%PaperYard WastePlasticsWoodMetalsFood WasteGlassOther
Total 151.9 million tons of trash per year
What is a trash?Trash is a rubbish people throw away
because they can no longer use it.Trash can be household, commercial or
industrial.There can be variations in the trash
produced depending on the consumption.
These huge sums of trash cannot be kept in open.
They increase toxicity of the environment and there will be no fresh air to breathe.
It promotes increase of parasites and give birth to many diseases.
So to dispose of these wastes various waste disposal techniques are used.
Of all the techniques, efficient ones are
Landfill Sites
What is a landfill site?A landfill site is a licensed facility where waste is
deposited for permanent disposal. It is a structured place
Whereas, a dumping site is a site same as a landfill but it is not properly structured.
Probably it is a hole or a pit where waste is over thrown.
A Landfill Cell
Tractors Compact Waste to Create Layers in a Landfill Cell
The goal of a landfill is to cover it, isolate it, and keep it from contaminating our air and
groundwater.
Problems the Landfill sites poseGroundwater ContaminationProduction of Landfill Gas Landfill firesOffensive odoursLitterPests (Vermin, seagulls, flies)Increased traffic for duration of infillingLong term settlement after completion
Groundwater ContaminationGroundwater contamination can occur if
Leachate leaks into the soils and rock surrounding a landfill site, eventually making its way to the water table.
Leachate is formed when water percolates through solid waste.
It can be highly toxic.
Landfill Gas
Landfill gas is produced during the natural breakdown of biodegradable waste.
The composition of landfill gas changes over time.
The gas from a typical landfill site consists mostly of methane and carbon dioxide.
Landfill fires
As waste decomposes it generates heat and underground fires may start.
These are difficult to extinguish, may last for long periods, and may spread throughout the landfill.
How are landfills made
Landfill DesignModern landfills are designed to minimise these
problems:◦ Location◦ Landfill Liner◦ Compaction of waste◦ Daily Cover ◦ Landfill Cap◦ Leachate Management System◦ Landfill Gas management System
Location In order to obtain a permit a landfill operator must first carry out a
detailed investigation and prove to the satisfaction of the planning authority and the EA that the site: ◦ is located in a geologically stable area◦ is not located on a major aquifer;◦ Is not located in a vulnerable area;◦ is designed to reduce the risk of damage to the environment and
human health;◦ will be monitored regularly for the duration of operations and
aftercare period.
Liners Landfill Liners are constructed on the base and sides of a landfill
site to prevent Leachate from leaking into the surrounding soils. Landfill Liners may be constructed from:
◦ Compacted Clay◦ Bentonite Enhanced Sand◦ Geomembrane◦ Geotextile Protector◦ Dense Asphaltic Concrete (DAC)◦ Combination of the above
How is Landfill operated
Waste is placed in layers approximately 3 m thick and compacted.
At the end of each working day approximately 0.3 m of clay or sand material is placed on top of the waste to:◦ minimise the infiltration of rainwater◦isolate the waste from birds and vermin◦reduce odours
Landfill operations
Landfill operations
To prevent wastage and the formation of layers of weakness within the waste mass the daily cover is scraped off and re-used each day.
Leachate that collects at the base of the waste mass is collected and re-circulated into the waste. This:◦increases the rate of decomposition of the waste and
therefore, rate of settlement;◦decreases disposal costs.
LANDFILL CAP• Landfill caps placed above the waste
after completion of infilling prevent the infiltration of rainwater, minimising the production of Leachate.
• Landfill Caps are usually constructed from:– Recomputed clay– Geomembrane
Leachate management systems
Leachate management systems are installed to:◦prevent the accumulation of leachate in the base of
the landfill ◦collect, re-circulate and dispose of leachate during
operations and after closureThey comprise of:
◦ leachate drainage blanket at base of landfill◦pipes along base and sidewalls of landfill◦wells to monitor and extract the leachate
Landfill gas management systemLandfill gas management systems are installed
to prevent the build up of gases within the landfill and to prevent migration of landfill gas through the underlying strata.
There are 2 ways landfill gas can be managed:◦passive◦active
Passive management systems comprise of wells with perforated tops to allow the gas to vent into the atmosphere
Active management systems involve the active extraction of the gas.
The extracted gas can be used to generate electricity.
Electricity generating
system
MonitoringMonitoring is carried out before, during, and after the
placement of waste.Numerous monitoring wells are constructed around a
landfill site (both upstream and downstream) to check for contamination.
Chemical testing is carried out regularly on: ◦Groundwater ◦Leachate◦Landfill Gas
Conclusion
Hence we conclude that landfill sites are not very pleasant and common to visit, but they help use to
reduce the negative effects caused by wastes
generated by humans.
Thanking you