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Class 9 · Water Security · 10 Aug 2026

Max marks: 40
Grade Class 9 · Water Security · 18 questions
Name Class Date
Q.1 MCQ [2 marks]
(a)
During the festival of Ganesh Chaturthi in Mumbai, immersion of idols made of Plaster of Paris (PoP) and synthetic paints introduces which of the following primary pollutants into water bodies?
[1 mark]
(a)  Biodegradable cellulose fibers
(b)  Heavy metals like lead and mercury from paints
(c)  Excess dissolved oxygen and nitrates
(d)  Chlorinated organic solvents
(b)
During festive celebrations like Ganesh Chaturthi in Mumbai, immersion of idols made of Plaster of Paris (PoP) and synthetic paints primarily contributes which pollutant to marine and lake waters?
[1 mark]
(a)  Biodegradable organic manure
(b)  Heavy metals such as lead and mercury from paints
(c)  Nitrogenous fertilizers causing sudden eutrophication
(d)  Radioactive isotopes from medical waste
Q.2 Match the Pairs [6 marks]
(a)
Match the traditional water bodies from Column A with their primary characteristic or regional context in India from Column B.
[2 marks]
Column AColumn B
1. Pushkar Lake a. Eutrophic crater lake formed by a meteorite impact in Maharashtra
2. Dal Lake b. Sacred natural/artificial lake in Rajasthan
3. Vembanad Lake c. Urban lake in Srinagar famous for floating gardens
4. Lonar Lake d. Longest backwater lake in Kerala used for boat races
Answer
(b)
Match the water pollutant or condition in Column A with its primary health or ecological effect in Column B.
[2 marks]
Column AColumn B
1. Mercury in fish a. Blue baby syndrome
2. Excess nitrates in drinking water b. Reduction in dissolved oxygen solubility
3. Untreated sewage c. Minamata disease
4. Thermal pollution d. Waterborne cholera and typhoid
Answer
(c)
Match the water pollution prevention strategy with its correct description:
[2 marks]
Column AColumn B
1. Rainwater Harvesting a. Advanced filtration to remove residual nitrates and phosphates from STPs
2. Nutrient Management b. Capturing rooftop runoff to recharge groundwater and reduce runoff volume
3. Bioremediation c. Optimizing fertilizer application timings to prevent agricultural runoff
4. Tertiary Treatment d. Using specific microbial strains to degrade organic pollutants in drains
Answer
Q.3 Fill in the Blanks [3 marks]
(a)
An underground water-bearing stratum of permeable rock, gravel, or sand from which groundwater can be extracted using a tube well is called an _____.
[1 mark]
(b)
A _____ is a traditional stepwell found in arid regions of western India, designed to reach the underground water table.
[1 mark]
(c)
The process by which nutrient enrichment of water bodies leads to excessive algal growth, subsequent oxygen depletion, and aquatic organism death is called _____.
[1 mark]
Q.4 One Sentence [6 marks]
(a)
Define a Baoli (stepwell) in the context of medieval Indian water architecture.
[1 mark]
(b)
State the primary environmental objective of installing an Effluent Treatment Plant (ETP) in chemical manufacturing industries across Gujarat.
[2 marks]
(c)
Propose a scientific justification for why constructing artificial recharge shafts directly in dry lake beds is an effective strategy for reviving regional groundwater tables.
[3 marks]
Q.5 Short Answer [6 marks]
(a)
Explain how a *Khadin* system works in the Thar Desert to support both agriculture and moisture conservation.
[3 marks]
(b)
Explain how excessive chemical fertilizer runoff from agricultural fields into a rural lake can trigger the process of cultural eutrophication. State two primary consequences for the lake ecosystem.
[3 marks]
6.
Design a decentralized wastewater management framework for a newly planned eco-housing township of 5,000 residents in Bengaluru. Your design must integrate source segregation, greywater recycling, decentralized secondary biological treatment, and tertiary disinfection. Detail the flow of water and justify how this decentralized model prevents urban lake pollution compared to conventional centralized sewerage.
[5 marks]
Q.7 Word Problem [7 marks]
(a)
A local municipal corporation in a tier-2 Indian city samples sewage entering a local river. The lab report shows an average Biochemical Oxygen Demand (BOD) of 350 mg/L from untreated domestic sewage, whereas treated effluent should ideally be below 30 mg/L. Explain the chemical and biological processes causing this high BOD value.
[3 marks]
(b)
A municipal corporation in a tier-2 Indian city plans to install an Effluent Treatment Plant (ETP) cluster for 5 small-scale electroplating units. Each unit discharges 15,000 liters of wastewater daily containing heavy metal ions. Calculate the total daily volume of wastewater in kiloliters (kL) that the common ETP must be designed to process, and state two key chemical processes required in heavy metal removal.
[4 marks]
Q.8 Diagram Labeling [5 marks]
(a)
Identify the standard geological zones in a cross-section showing a well penetrating an unconfined aquifer.
[2 marks]
Label the following: 1 2 3 4
(b)
Study the aquatic food chain diagram below representing biomagnification of a toxin, and identify the labels for trophic levels A through D in order.
[3 marks]
Label the following: 1 2 3 4
Generated by Lumai — 04 November 2026
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Class 9 · Water Security · 10 Aug 2026 — 40 marks