For Prelims: Biochemical oxygen demand, Faecal coliform, Dissolved oxygen, Most probable number
For Mains: Environment: Water pollution and water-quality indicators; Geography: Rivers and water resources
Source:
Hindustan
5 facts for one-day exams
SSC, railway, police and teaching exams ask direct questions like these.
- ISBT Bridge recorded Yamuna BOD of 30 mg/L.
- Asgarpur recorded 38,000 MPN per 100 mL of faecal coliform.
- The stated bathing-water BOD benchmark is 3 mg/L.
- Yamuna samples were collected on 7 September 2026.
- The Delhi Pollution Control Committee published the report on 30 September 2026.
The news
The Delhi Pollution Control Committee (DPCC) report published on 30 September 2026 has identified five locations along the Yamuna in Delhi where water quality indicators far exceed safe limits for bathing. Samples collected on 7 September showed the highest biochemical oxygen demand (BOD) of 30 mg/L at ISBT Bridge, ten times the benchmark of 3 mg/L for bathing water. The report comes amid political blame over dead fish in the river during the Chhath festival, with BJP minister Pravesh Verma alleging that AAP dumped dead fish, while AAP countered that chemicals caused the fish kill.
BOD readings at the other four monitored locations were 18 mg/L at ITO Bridge, 16 mg/L at Asgarpur, 12 mg/L at Nizamuddin Bridge and 10 mg/L at Okhla Barrage, all exceeding the 3 mg/L standard. Faecal coliform counts, which indicate contamination from human and animal waste, were highest at Asgarpur at 38,000 MPN per 100 mL, more than 15 times the maximum permissible limit of 2,500 MPN per 100 mL for bathing water. ISBT Bridge recorded 35,000, Okhla Barrage 21,000, ITO Bridge 17,000 and Nizamuddin Bridge 15,000 MPN per 100 mL. Dissolved oxygen levels at some monitoring stations were below the 5 mg/L benchmark needed to sustain fish and other aquatic life, officials said.
Yamuna pollution hotspots Delhi: why in the news?
The DPCC report published on 30 September 2026, with samples collected on 7 September, has revealed the worst pollution hotspots in the Yamuna during the Chhath festival, when political parties traded allegations over dead fish in the river.
What do BOD, faecal coliform and DO measure?
Biochemical oxygen demand (BOD) measures the oxygen consumed by bacteria to break down organic waste in water; higher BOD means more organic pollution. Faecal coliform bacteria indicate contamination from faeces and sewage. Dissolved oxygen (DO) is the oxygen available in water for fish and other aquatic organisms. The Central Pollution Control Board sets a BOD of 3 mg/L or less and a faecal coliform count of 2,500 MPN per 100 mL or less as safe for bathing.
Which locations are the most polluted and by how much?
ISBT Bridge had the highest BOD at 30 mg/L, ten times the bathing standard. Asgarpur had the highest faecal coliform count at 38,000 MPN per 100 mL, 15.2 times the limit. All five monitored locations exceeded both the BOD and faecal coliform benchmarks. Some stations recorded DO below the 5 mg/L standard, which can stress or kill aquatic life.
Yamuna water quality at five locations
| Location | BOD (mg/L) | Faecal coliform (MPN/100 mL) |
|---|---|---|
| ISBT Bridge | 30 | 35,000 |
| ITO Bridge | 18 | 17,000 |
| Asgarpur | 16 | 38,000 |
| Nizamuddin Bridge | 12 | 15,000 |
| Okhla Barrage | 10 | 21,000 |
Delhi connection
Matters for these Delhi exams:DSSSB
Yamuna pollution hotspots Delhi: facts and terms for exams
- Biochemical oxygen demand:
- The amount of dissolved oxygen used by microorganisms to break down biodegradable organic matter in water under specified conditions.
- Faecal coliform:
- A group of bacteria whose presence in elevated concentrations indicates faecal contamination of water.
- Dissolved oxygen:
- Oxygen dissolved in water and available to aquatic organisms.
- Most probable number:
- A statistical estimate of the concentration of microorganisms in a sample.
Yamuna pollution hotspots Delhi: why it matters for exams
Exams: DSSSB
Syllabus: Environment: Water pollution and water-quality indicators; Geography: Rivers and water resources
Common mistake: Examiners may swap the two highest-ranking locations: ISBT Bridge had the highest reported BOD, while Asgarpur had the highest faecal coliform count.
Mains question on Yamuna pollution hotspots Delhi
The DPCC report shows Yamuna BOD and faecal coliform levels far exceed safe limits at multiple locations in Delhi. Critically examine the causes of such pollution and the effectiveness of existing river-cleaning measures.
Stuck? Get it in one tap
BOD measures how much oxygen microorganisms use to break down organic matter in water. A high value indicates more organic pollution. Faecal coliform bacteria indicate contamination from faecal matter, while low dissolved oxygen can harm aquatic life.
- Environment: Water pollution and water-quality indicators
- Geography: Rivers and water resources
Related concepts: Biochemical oxygen demand, Faecal coliform, Dissolved oxygen, Most probable number
Practice questions
Pick an answer, then read the explanation.
- Q1Easy
Which body published the September 2026 Yamuna water-quality report for Delhi?
Explanation: The Delhi Pollution Control Committee published the water-quality report. The cabinet is a governing body, the National Capital Region is a geographical region, and ISBT Bridge is a monitoring location.
- Q2Hard
Consider the following statements about the September 2026 Yamuna water-quality measurements:
- 1.ISBT Bridge recorded a BOD of 30 mg/L.
- 2.ISBT Bridge had a higher faecal coliform count than Asgarpur.
- 3.Some monitoring stations recorded dissolved oxygen below 5 mg/L.
Which of the statements given above is/are correct?
Explanation: Statements 1 and 3 are correct: ISBT Bridge recorded 30 mg/L BOD, and dissolved oxygen fell below 5 mg/L at some stations. Statement 2 is incorrect because ISBT Bridge recorded 35,000 MPN per 100 mL, less than Asgarpur's 38,000.
- Q3Medium
What faecal coliform count was recorded at Asgarpur in the September 2026 Yamuna water-quality report?
Explanation: Asgarpur recorded 38,000 MPN per 100 mL. The corresponding counts were 35,000 at ISBT Bridge, 21,000 at Okhla Barrage and 17,000 at ITO Bridge.
- Q4Medium
What does a high biochemical oxygen demand in Yamuna water primarily indicate?
Explanation: High BOD indicates greater oxygen consumption associated with decomposition of organic matter. It does not establish greater oxygen availability, lower microbial oxygen consumption or an absence of organic matter.
Frequently asked questions
1. Which Yamuna location had the highest BOD in Delhi's September 2026 measurements?
ISBT Bridge recorded the highest reported BOD at 30 mg/L.
2. Where was the highest faecal coliform count recorded in the Yamuna?
Asgarpur recorded 38,000 MPN per 100 mL, the highest among the five reported locations.
3. When were samples collected for the September 2026 Yamuna report?
Samples were collected on 7 September 2026; the report was published on 30 September 2026.
4. Why is dissolved oxygen important for the Yamuna?
Dissolved oxygen is needed by fish and other aquatic organisms. Low levels can make their survival difficult.
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- Original14 November 2026 · Read story
