Water Pollution in India — MCQs with Answers

The Water Act, 1974 created the Central Board (section 3) and State Boards (section 4). Both boards were first set up under this Act. Later laws gave them more work.

BOD is the oxygen that aerobic organisms need to break down organic matter. The standard test runs for 5 days at 20 °C. The result is given in mg of oxygen per litre.

Microbes use up oxygen to break down organic waste. More waste means more oxygen demand. So a high BOD means heavy organic pollution.

DO shows whether a water body can support fish and plants. Organic wastewater does the opposite of statement 2. Microbes use up oxygen as they break the waste down, so DO falls.

Extra nutrients make algae and plants grow too fast. Fertiliser runoff and sewage are common sources.

Blooms die and decay, and microbes use up oxygen as they do so. That lowers oxygen, often causing dead zones and fish kills. Oxygen near the bottom does not rise.

Polluted stretches are those with BOD above 3 mg/L. Higher BOD means heavier pollution.

CPCB’s 2022 report found 311 polluted stretches on 279 rivers. That is down from 351 in 2018. Note that 279 is the number of rivers, not stretches.

Priority I means BOD above 30 mg/L, the worst category. Priority II is 20–30, III is 10–20, IV is 6–10 and V is 3–6 mg/L.

Priority V covers BOD of 3–6 mg/L, the mildest category. Priority IV is 6–10, III is 10–20, II is 20–30 and I is above 30 mg/L.

The programme began with an outlay of ₹20,000 crore, and the sum has grown since. Funds go to the NMCG, which runs the mission. Both statements are correct.

The decision was taken on 5 October 2009. The dolphin is in Schedule I of the Wildlife (Protection) Act, 1972.

The NGT directed States and UTs to put approved action plans in place for polluted stretches. These include sewage treatment plants. It did not order a ban on riverside industry.

CPCB’s ZLD directions were issued for specific sectors on the Ganga, with time limits. They are not a rule for every industry in India. So only statement 1 is correct.

The Jal Shakti Ministry said in December 2022 that arsenic was reported from certain points of 221 districts in 25 States/UTs. A December 2024 Rajya Sabha answer gives 230 districts in 25 States.

CPCB calls a stretch polluted when its BOD is above 3 mg/L. Class V covers 3 to 6 mg/L. Class I is the worst, with BOD above 30 mg/L.

Both statements are correct. The report lists 296 stretches on 271 rivers in 32 States and UTs. Class I is the worst class, with BOD above 30 mg/L.

The 2024 amendment replaced jail with a money penalty for Section 24. The range is Rs 10,000 to Rs 15 lakh, plus Rs 10,000 for each day it continues. An adjudicating officer decides it.

The five sectors were pulp and paper, distilleries, sugar, tanneries and textiles. Cement was not among them.

Statements 1 and 2 are correct. Section 25 needs prior consent, and failing Section 25 or 26 can mean 1 year 6 months to 6 years in jail. Statement 3 is wrong: Section 24 now draws a money penalty.