The decomposition of garbage very much involves the work of bacteria. The rate of decomposition is enhanced by the presence of leachate. As the wastes are degraded by the bacteria, gases are emitted mainly methane. Methane is a greenhouse gas whose emissions pose a threat to the environment (WeGreen-USA, 2014)
The liquid that percolates or filters through the dump is referred to as Leachate. The sources of leachate would be rainwater or the liquids in the waters. Rainwater normally hit collected trash; pooling occurs and run off may ensue. The lacerate would thus become toxic since it will mix ground water (WeGreen-USA, 2014).
The landfills are the most commonly used method of waste disposal. The old landfills were mainly composed of a bottom liner and a cover. The old landfills failed to adequately prevent the contamination of the environment with wastes. The leachate was not collected hence it trickled down to the ground bringing about the contamination of ground water. In addition, the wastes were exposed to the environment hence attracting pests. The decomposition of older landfills took more time since cover of the landfills was not properly structured.
The modern landfill contains a leachate collecting system, a bottom liner and a cover. This minimizes the possibility of wastes escaping into the ground. The modern landfills are constructed with safeguards. The water is normally covered to avoid attracting the pests. In addition, compaction of the waste is carried out order to increase the density and stability. This means that more waste can be disposed of using the landfill method. Modern landfills are designed in ways that protect the environment from contamination. Landfills prevent hydraulic connections between the waste and the environment mainly ground water (WeGreen-USA, 2014)
The old landfills were not properly structured and allowed communication with the environment. This can be attributed to the poor ground layer, the