Knowledge Nugget: Why is CPCB report on river pollution important for UPSC Exam?

Why in the news?

Maharashtra continues to have the highest number (54) of polluted river stretches, according to a Central Pollution Control Board (CPCB) assessment report released Monday (22nd September). The previous assessment for identifying polluted stretches was carried out in 2022, using data from 2019 and 2021, while 2020 was omitted due to the pandemic.

Key takeaways:

1. The CPCB reviewed water quality data from 2022 and 2023, covering 2,116 locations, and found that 296 river stretches were polluted on 271 rivers across 32 states and Union Territories. The number of polluted river stretches in India have decreased marginally from 311 to 296.

2. Out of 296 stretches identified as polluted, 37 were classified as the most polluted, or Priority I (biochemical oxygen demand concentrations exceeding 30 mg/L). This number has also seen a slight drop from 46 in the previous report.

3. These 37 stretches were identified across 14 states, with the highest number, five, in Tamil Nadu, Uttar Pradesh, and Uttarakhand; four in Gujarat, and three in Karnataka.

4. Among the most notable polluted river stretches included Yamuna’s stretch from Palla to Asgarpur in Delhi, Sabarmati in Ahmedabad, Chambal’s stretch from Nagda to Gandhisagar dam in Madhya Pradesh, and stretches of Tungabadhra and Sarabanga in Karnataka and Tamil Nadu, respectively.

5. Among the more prominent rivers where stretches were identified to have deteriorated in quality were Jhelum in Jammu and Kashmir; Ganga, Ramrekha and Sikrahna in Bihar; Hasdeo, Mahanadi in Chhattisgarh; Sal and Mapusa in Goa; Cauvery, Tungabhadra in Karnataka; Periyar in Kerala, and Amba and Savitri in Maharashtra. It also included stretches on Krishna in Telangana and Kosi in Uttarakhand.

1. 01

   What is biochemical oxygen demand (BOD)?

   BOD is a key indicator of river water quality. It measures the oxygen needed to break down organic matter. Any location/stretch of the river having a Biological Oxygen Demand (BOD) of more than 3mg/l is identified as polluted and unsuitable for outdoor bathing.

2. 02

   What is a polluted river stretch?

   A polluted river stretch refers to two or more polluted locations on a river in a continuous sequence. Stretches where the biochemical oxygen demand (BOD) exceeds 3 milligrams/litre (mg/L) are identified as polluted stretches by CPCB. BOD in excess of prescribed levels indicates a higher pollution load, especially for the health of aquatic life.

3. 03

   What are the priority categories of river water quality?

   There are five such priority categories.

   (i) Priority –I indicates ‘critically polluted’ with BOD>30 mg/l

   (ii) Priority-II indicates ‘severely polluted’ with BOD between 20 to 30 mg/l

   (iii) Priority-III indicates ‘moderately polluted’ with BOD between 10 to 20 mg/l

   (iv) Priority-IV indicates ‘less polluted’ with BOD between 6-10 mg/l

   (v) Priority –V indicates ‘non-polluted’ with BOD 3 to 6 mg/l

4. 04

   Which Act provides statutory backing to the CPCB?

   The primary legislation related to water pollution in India, including river pollution, is the Water (Prevention and Control of Pollution) Act, 1974, which establishes the CPCB as the central unit for planning and regulating environmental matters and SPCB as a state-level major institution with the responsibility to enforce environmental standards. The National Water Quality Monitoring Programme was started by CPCB in 1978 under the Global Environmental Monitoring System (GEMS), Water Programme.

Namami Gange Programme (NGP)

1. The NGP, launched in 2014 as the Government of India’s flagship programme, aims to improve the water quality and ecological status of the Ganga. It superseded the Ganga Action Plan (GAP) which was launched in 1985. NGP is being implemented by the National Mission for Clean Ganga (NMCG). It adopted a holistic approach and has made considerable progress on the issue of sewage treatment facilities.

2. It is 100% centrally funded. It was launched with twin objectives of effective abatement of pollution, conservation and rejuvenation of the National River Ganga. Notably, the World Bank and the Government of India have also signed a loan agreement to enhance support for the Namami Gange program.

3. The programme marks a shift from pollution abatement to improving the ecological condition of the river. The NGP has pursued a river basin approach informed by a plan produced by a consortium of the Indian Institutes of Technology.

4. The main pillars of the programme are Sewerage Treatment Infrastructure, River-Front Development, River-Surface Cleaning, Afforestation, Industrial Effluent Monitoring, Public awareness, and Ganga gram.

BEYOND THE NUGGET: Major causes of river pollution

1. Untreated sewage: Among all the anthropogenic sources, untreated sewage remains the primary reason behind river pollution in India. According to the CPCB, more than 60% of untreated sewage water is released into rivers daily, which makes the water unsafe and creates serious problems for the local population and aquatic ecosystem.

2. Untreated industrial effluents: After untreated sewage, untreated industrial effluents are a major cause of river pollution. Industries such as those producing chemicals, sugar, paper, and tanneries generate wastewater that contains toxic chemicals, which poses serious risks and potentially fatal consequences in some cases.

3. Agricultural runoff: Agricultural runoff further contributes to river pollution. It contains pesticides and fertilisers, which introduce toxic chemicals into the water. The nutrients like nitrogen in the runoff can also cause eutrophication – a process that depletes oxygen in the water and thereby increases the BOD of the river.

4. Sand mining and illegal encroachment: Furthermore, sand mining and illegal encroachment are also becoming significant contributors to river pollution. These activities disrupt the natural flow of rivers, increase the risk of flooding in local areas, and add to river pollution due to inadequate waste management facilities.

 Post Read Questions

(1) Consider the following statements about the Namami Ganga Programme:

1. It is a centrally sponsored scheme.

2. The World Bank is funding the projects through loans.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) None of the above

(2) Biological Oxygen Demand (BOD) is a standard criterion for (UPSC CSE 2017)

(a) Measuring oxygen levels in blood

(b) Computing oxygen levels in forest ecosystems.

(c) Pollution assay in aquatic ecosystems

(d) Assessing oxygen levels in high altitude regions.

(Sources: Rivers in peril: How pollution endangers India’s water lifelines, Namami Gange project: Let the rivers talk to each other, unstats.un.org, nmcg.nic.in)

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