IELTS Task 1: Urban Rainwater Treatment (Process Diagram)

The Task

The diagram below illustrates the process by which rainwater is collected, treated, and distributed for household use in an urban area. Summarise the information by selecting and reporting the main features, and make comparisons where relevant. Write at least 150 words.

1
Rainfall collects in a river or reservoir.
2
Water is pumped to a screening plant where large debris is removed.
3
Water passes through sedimentation tanks and particles settle.
4
Chemicals are added (coagulation / flocculation stage).
5
Water is filtered through sand and gravel.
6
Chlorination and pH adjustment take place.
7
Treated water is stored in covered service reservoirs.
8
Water is distributed via underground pipes to homes, schools and businesses.

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Sample Band 8 Response

156 words

Model answer written by EduForEveryone — for guidance only. Not an official examiner response.

The diagram illustrates the stages by which rainwater is collected, treated and supplied to households in an urban area.

Overall, this is a linear, one-directional process that begins with the natural collection of rainwater and ends with treated water being delivered to consumers, with the majority of stages dedicated to cleaning and purification.

At the first stage, rainfall gathers in a river or reservoir, from which it is pumped to a screening plant where large debris is removed. The water then flows into sedimentation tanks, allowing suspended particles to settle, before chemicals are added during the coagulation and flocculation stage.

Following this, the water is filtered through layers of sand and gravel and undergoes chlorination and pH adjustment to make it safe to drink. The purified water is subsequently held in covered service reservoirs. Finally, it is distributed through underground pipes, branching out to supply both residential homes and commercial premises such as schools and businesses.