Process diagram #8: The diagram below describes how storm water is recycled in an Australian city

Task 01: Process

The diagram below describes how storm water is recycled in an Australian city.

Sample Answer 1 :

The diagram illustrates the process of harvesting and recycling stormwater for use by residents in an Australian city.

Overall, there are around 9 stages in the process of providing recycled rainwater to Australian households, including the collection of rainwater, treatment, and distribution of the end product.

The first step in the process is the collection of rainwater after a large downpour. Rain flows through drains in the ground and into pipes where it is transferred to a water recycling plant. There are four stages of filtration at the plant, beginning with the removal of plastic and other rubbish. (1) Next, small particles are removed from the water, followed by bacteria and viruses. Lastly, tiny molecules and salt are also removed.

After undergoing the recycling process at the plant, chlorine is added to the water, at approximately 4mg/litre for further treatment. The water is then transferred via pipes to large storage tanks where it can be easily distributed to Australian households.

(160 words)

Sample Answer 2 :

The diagram provides a breakdown of stormwater harvesting in an unspecified Australian city. The initial impression from the diagram is that rainwater from drains undergoes various physical and chemical processes underground to become clean water which is stored and then reused on sunny days.

The process commences when stormwater runoff is collected from drains and then flows in pipes into an underground water recycling plant where it goes through four distinct treatment phases. Large wastes such as plastic and rubbish are discarded in the first phase, and smaller particles are later filtered out in the second phase. Microscopic impurities such as bacteria, viruses, molecules, and salt are then removed in the third and fourth phases.

Once purified, stormwater is chlorinated at 4mg/l, after which it is stored in a chamber. The process ends when the water, now safe for domestic use, is sent back to Australian households and reused on sunny days.

(153 words)