 Landfill Type  aerobic landfill  anaerobic sanitary landfill with daily cover  improve anaerobic sanitary landfill with buried leachate collection facilities  landfill with forced aeration

 Only the anaerobic and semi-aerobic landfill are desirable when leachate and gas quality to be considered

 Open dumping  potential source of disease  fires are uncontrolled  air pollution  smell  pollute nearby waterways & ground water  ugly  scavenging

Sanitary landfill  destruction of habitats - (wetland)  cause of urban land shortage  hence transportation cost – (distant)  lost of resources – cannot be replace  leachate leakage - (groundwater contamination)  maintenance after completion require 10 to 15 years  Non-available of suitable cover material

 Level of Sanitary Landfill  Level 1: control tipping  Level 2: sanitary landfill with bound and daily soil cover  Level 3: sanitary landfill with leachate recirculation  Level 4: sanitary landfill with leachate treatment facilities.

 Landfill Technology  The most common landfill technologies are  area method  trench method  ramp method  sandwich method

Area method/Depression  terrain is unsuitable for the excavation of trenches  Solid waste cells constructed in a large area  layers of cells are created until the permitted height reached  Each cell represents the waste received and compacted in place and covered each day.

 Can accommodate very large volume operation  Earth dyke with height of one lift (2-3 m) is first constructed to gate the support for compacting.  The wastes are unloaded at the top of the earth dyke and spread and compacted on the slope of the dyke.  The layers dept is from 30 – 60 cm.

 Depression method best for area where natural depression exist.  The installation liners and leachate collection system is relative easy.  The earth cover of this system is usually obtain from borrow-pit or brought from elsewhere.

Area method

 Trench Method  Waste is spread and compacted in an excavated trench  The excavator tailings are used as cover material  Best for flat land where the excavation of trenches can be carryout easily.  The ground water level should be sufficiently low

 The trench size varies in length and width:  dept:1 – 2 metre  width: 2 – 5 metre  length:30 – 120 metre  Wastes are spread into thin layers from cm and compacted before soil cover in introduced.

Trench Method

 Ramp method  also call progressive slope.  A combination of area method and trench method  Solid waste is spread and compacted on a slope  cover material is obtained directly from the front of the working face.  The excavation of cover material provides a depression for the next day waste.

 Ramp is about 15 metre wide and 30 metre length and suitable height.  Trucks come on the top of the ramp and discharge their contents inside the trench.

 Sandwich method  Used when the solid waste is deposited horizontally into narrow valleys.  Cover soil layer is added over each layer of solid waste

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