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Unlock This CourseThe spec asks for one detailed example of the causes and impacts of pollution in a named river, and how that pollution is managed. Our example is the River Ganges (called the Ganga in India). It shows ideas from River Pollution: Causes and Impacts and Managing River Pollution in one place. Here we apply them rather than teach them again.
Location: the Ganges rises in the Himalayas, at the Gangotri Glacier in the Indian state of Uttarakhand. It flows about 2,500 km south-east across the northern plains of India, then through Bangladesh, and ends in the Bay of Bengal. Its tributaries and the big cities on its banks, such as Kanpur and Varanasi, are the places to name in an answer.
Why it is important:
1985: the Ganga Action Plan begins, the first big national plan to clean the river.
1990s to 2000s: towns and cities keep growing and the river stays badly polluted.
2014: the Namami Gange programme is launched, with a much bigger budget.
From 2015: hundreds of new sewage treatment plants are built or planned along the river.
Most of the pollution comes from people, and many of the causes are point sources and non-point sources you have already met.
Rapid population growth makes it worse. More people means more sewage, more waste and more demand for water, and the river's flow is also reduced by water being taken out for farming.
| Type | Impacts |
|---|---|
| Social | People who drink, wash in or cook with the water can get water-borne diseases such as diarrhoea, cholera and typhoid. Children are most at risk. Bathing, a key part of worship, can make people ill. |
| Economic | Fish catches fall, so fishing families lose income. Polluted water harms crops and costs more to treat. Illness means lost work and medical bills. Tourism and pilgrimage can be put off. |
| Environmental | Oxygen levels fall and fish die. Wildlife such as the endangered Ganges river dolphin is harmed. Chemicals build up in food chains. |
Scale: the impacts are local (people at the river's edge in Varanasi), regional (the whole Ganges plain) and national (health costs and loss of a sacred river). The polluted water also flows on into Bangladesh and the Bay of Bengal.
Strategies are the plans. Techniques are the methods.
Sustainable parts: sustainable means meeting today's needs without harming the future. Planting trees along the banks, protecting wetlands and wildlife, using treated water again and teaching people not to dump rubbish are sustainable, because they keep helping the river long after the money is spent.
| Strengths | Weaknesses |
|---|---|
| Many new treatment plants have been built, so more sewage is treated than in 1985. Industry is monitored more closely. Public awareness has grown, and some stretches and ghats are cleaner. | Population growth means sewage still outpaces the plants, and a large share is still untreated. Some plants broke down or were poorly kept in the Ganga Action Plan. Rules for factories are not always enforced. Religious practices are hard to change, and farm runoff is hard to control. |
Who benefits? People living by the river and downstream, fishing families and wildlife. Overall: there has been progress, but the Ganges is still badly polluted in many places, so the plans have been only partly successful. The long-term answer is prevention at the source as well as treatment.
Writing only general points about "river pollution" with no Ganges detail. Name Kanpur, Varanasi, tanneries, the Ganga Action Plan and Namami Gange. Another mistake is saying the plans worked fully or failed completely. A good evaluation gives both sides and a judgement.
Fig. 1.1 shows made-up results of water tests at three places on a river in northern India.
| Site | Place | Dissolved oxygen (mg per litre) |
|---|---|---|
| A | Above the city | 8.0 |
| B | Next to the city | 3.5 |
| C | 20 km below the city | 5.0 |
(a) Identify the site with the lowest dissolved oxygen. [1 mark]
(b) Describe the pattern in the results. [2 marks]
(c) Explain two causes of pollution in a named river you have studied. [4 marks]
(d) Evaluate the strategies and techniques used to manage pollution in a named river you have studied. [6 marks]
(a) Site B. (1)
(b) Oxygen falls from 8.0 at Site A to 3.5 at Site B next to the city (1), then rises again to 5.0 at Site C, but stays below the level above the city (1).
(c) In the Ganges, untreated sewage from cities such as Kanpur and Varanasi flows into the river (1) because treatment plants cannot cope with so many people (1). Tanneries at Kanpur release waste containing chromium (1), which poisons the water and the animals in it (1).
(d) Level 3 (5-6 marks): The Ganga Action Plan (1985) built treatment plants and intercepted drains, and Namami Gange (from 2014) has a bigger budget, with more plants, river-front development, monitoring and awareness. These have strengths: more sewage is treated, factories are monitored, and some ghats are cleaner. Sustainable parts such as tree planting and public awareness keep helping the river. However, there are weaknesses. Population growth means much sewage is still untreated, some plants broke down, and factory rules are not always enforced. The people who benefit most are those living by the river and the wildlife, such as the river dolphin. Overall the management has been partly successful: it has improved some stretches, but the river is still badly polluted, so more prevention at the source is needed.
For an "Evaluate" question on an example, use three steps: name the plan and what it did, give a strength and a weakness with Ganges detail, then finish with a judgement.