The diagram illustrates how a modern site for burying domestic rubbish is built, filled and sealed.
Overall
, it is clear from the data that the process consists of three phases, with the majority of the work taking place during construction, and the amount of waste rises steadily until the pit is full, so the design stops harmful substances from escaping into the ground.
The first part of the figure depicts the initial step, in which a hole is dug in rock to a depth of approximately ten metres. Linking Words
Next,
the base and sides are covered with a layer of clay, which remains the thickest barrier throughout the period of use. Linking Words
In addition
, a synthetic lining is laid on top because it reduces the rate of leakage significantly. Linking Words
Subsequently
, drainage pipes are installed at the bottom so that the level of moisture stays low. Linking Words
Moreover
, lorries deliver household waste, and the liquid produced by decay is collected through the pipes.
The second part of the picture shows that the proportion of space remaining falls to zero at the final stage. After that, a clay cover is spread over the surface. Linking Words
Furthermore
, a vertical pipe releases the gases. Linking Words
Finally
, if any step were omitted, pollution would reach the soil.Linking Words