Rivers Pollution
Rivers Pollution – Complete GK Module for Railway Exams
1. Overview & Key Facts
- Definition: Degradation of river water quality due to discharge of domestic, industrial, agricultural & solid wastes beyond the assimilative capacity of the river.
- Global ranking: 70 % of India’s surface water resources are polluted (NITI Aayog 2023).
- Economic loss: World Bank (2020) estimated ₹8,000 crore/yr lost due to river pollution & health costs.
2. Major Polluted Rivers & Hot-spots
| River | Major Polluted Stretch | Main Pollutant | CPCB Category* (2022) |
|---|---|---|---|
| Ganga | Kanpur–Varanasi–Patna | Tannery effluent, Sewage | Priority Class-I |
| Yamuna | Wazirabad (Delhi)–Agra | Sewage, detergents | Priority Class-I |
| Sabarmati | Ahmedabad–Vadodara | Textile dyes | Priority Class-II |
| Damodar | Dhanbad–Asansol | Coal washery, heavy metals | Priority Class-II |
| Hindon (tributary of Yamuna) | Ghaziabad–Noida | Sugar & paper mills | Priority Class-II |
| Cauvery | Mettur–Erode | Dyeing units | Priority Class-II |
| Mahi | Vadodara–Anand | Chemical industries | Priority Class-II |
* CPCB “Priority Class” is based on Bio-chemical Oxygen Demand (BOD) > 30 mg/L & coliform count > 10,000 MPN/100 ml.
3. Sources of Pollution
| Source Type | Share (%) | Examples |
|---|---|---|
| Municipal sewage | ≈ 75 % | Untapped drains in 72 Ganga towns |
| Industrial effluent | ≈ 20 % | Tanneries (Kanpur), Textiles (Ahmedabad), Paper (Saharanpur) |
| Agricultural run-off | ≈ 5 % | Fertilizers (NPK), pesticides (Endosulfan) |
4. Critical Dates & Events
| Date / Year | Event |
|---|---|
| 14 Jan 1986 | Ganga Action Plan (GAP) – Phase-I launched by PM Rajiv Gandhi (world’s first river-specific plan). |
| 2014, 13 July | Namami Gange approved as an ₹20,000 crore flagship umbrella programme (100 % central share). |
| 2018 | National Mission for Clean Ganga (NMCG) upgraded to Authority (with powers of 1974 Water Act). |
| 2019, 31 May | Ganga Rejuvenation Bill introduced (still pending). |
| 2021 | Ganga Expressway (594 km) approved – NOT related to pollution but often asked. |
| 2022 | World Bank loan of ₹4,200 crore approved for Rejuvenation of Ganga & Yamuna. |
| 2023, Nov | **Lok Sabha passed “Water (Prevention & Control of Pollution) Amendment Bill” → decriminalises minor offences. |
| 2025 target | Zero liquid discharge (ZLD) for all Ganga tributaries (NMCG vision document). |
5. Institutional Framework
| Body | HQ | Parent Act / Ministry | Role Snapshot |
|---|---|---|---|
| CPCB | Delhi | Water (P&CP) Act, 1974 | Sets BOD/DO standards; colour-coded categorisation |
| NMCG | Delhi | MoWR, RD & GR | Implements Namami Gange, 305 projects sanctioned till 2024 |
| State PCB (e.g. UPPCB) | Lucknow | State act | Issues consent-to-establish (CTE) & consent-to-operate (CTO) |
| Ganga Task Force | Varanasi | MoEFCC | 4 battalions (ITBP) for eco-patrolling since 2016 |
6. Parameters & Standards (Quick Table)
| Parameter | CPCB Class-A* (Drinking-no treatment) | CPCB Class-C (Drinking-after treatment) | Yamuna at Okhla (2023) |
|---|---|---|---|
| BOD (mg/L) | ≤ 2 | ≤ 3 | 28 mg/L |
| DO (mg/L) | ≥ 6 | ≥ 4 | 0.4 mg/L |
| Faecal Coliform (MPN/100 ml) | ≤ 50 | ≤ 2,500 | 24,000 |
* River water is supposed to meet Class-C before human consumption.
7. Remediation Technologies
| Technology | River / Place | Feature |
|---|---|---|
| STP with MBBR (Moving-bed biofilm reactor) | Delhi (Coronation Pillar, 56 MLD) | 85 % BOD removal, energy-positive via biogas |
| Sewage-fed aquaculture | East Calcutta Wetlands (Ramsar) | Natural treatment + livelihood |
| In-situ bioremediation | Varanasi Assi drain | Microbial consortia, CPCB 2021 pilot |
| Gross-Effluent Tap (GET) system | Kanpur Jajmau | Real-time monitoring & auto-shut off |
8. One-Liner Revision Bullets
- Ganga = 2,525 km; 79 % stretch in UP-Bihar; 1,109 STPs sanctioned under Namami Gange (till 2024).
- Yamuna’s 22-km Delhi stretch accounts for 60 % of its total pollution load.
- Ganga’s Dolphin (Platanista gangetica) is indicator species – presence = good eco-health.
- CPCB 2018 “Rotten-River” tag: BOD > 30 mg/L → 46 stretches in 16 states.
- “Taj Trapezium Zone” (1982) covers 10,400 km² to protect Yamuna’s Agra stretch from air & water pollution.
- World Bank 2020 report: India loses 1.4 % GDP annually due to river pollution & inadequate sanitation.
- “One-Drop” principle (NMCG 2023): Every drop of sewage must be treated before entering river.
9. Quick-Fire MCQs (Railway Pattern)
1. Which river stretch has been categorised as “Priority Class-I” by CPCB in 2022?
Answer: Kanpur–Varanasi–Patna stretch of Ganga
2. The Ganga Action Plan Phase-I was launched in which year?
Answer: 1986
3. What is the total outlay approved for Namami Gange programme?
Answer: ₹20,000 crore
4. Which parameter is most commonly used to measure organic pollution in rivers?
Answer: BOD (Bio-chemical Oxygen Demand)
5. CPCB Class-C river water should have BOD not exceeding ___ mg/L.
Answer: 3 mg/L
6. The East Calcutta Wetlands use which eco-technology for treating sewage?
Answer: Sewage-fed aquaculture
7. Which organisation is entrusted with the implementation of Namami Gange?
Answer: NMCG (National Mission for Clean Ganga)
8. The “Ganga Task Force” is manned by which paramilitary force?
Answer: ITBP (Indo-Tibetan Border Police)
9. As per CPCB 2018, how many river stretches were labelled “Rotten-Rivers”?
Answer: 46
10. Which heavy metal is prominently found in the effluents of Kanpur tanneries?
Answer: Chromium
11. “Zero Liquid Discharge (ZLD)” target for Ganga tributaries has been set for which year?
Answer: 2025
12. Which state hosts maximum number of polluted river stretches as per CPCB 2022?
Answer: Maharashtra (20 stretches)
13. The Water (Prevention & Control of Pollution) Act was passed in which year?
Answer: 1974
14. Which dolphin species is considered an indicator of Ganga river health?
Answer: Ganges River Dolphin (Platanista gangetica)
15. World Bank’s 2020 assistance for Ganga & Yamuna rejuvenation is ___ crore.
Answer: ₹4,200 crore
16. “One-Drop” principle introduced by NMCG in 2023 relates to:
Answer: Mandatory treatment of every drop of sewage before river entry
17. CPCB is under the administrative control of which ministry?
Answer: Ministry of Environment, Forest & Climate Change (MoEFCC)
10. Mini-Map for Visual Memory (Text Mode)
Ganga (UP-Bihar)
├── Yamuna (Delhi-Agra)
│ └── Hindon (Ghaziabad)
├── Damodar (Jharkhand-WB)
├── Sabarmati (Gujarat)
└── Mahi (Gujarat-Rajasthan)
Remember: G-Y-D-S-M (Ganga-Yamuna-Damodar-Sabarmati-Mahi) are top-5 polluted as per CPCB 2022.
11. Key Abbreviations
| Abbreviation | Full Form |
|---|---|
| BOD | Bio-chemical Oxygen Demand |
| COD | Chemical Oxygen Demand |
| DO | Dissolved Oxygen |
| STP | Sewage Treatment Plant |
| ETP | Effluent Treatment Plant |
| ZLD | Zero Liquid Discharge |
| MPN | Most Probable Number (coliform count) |
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