Free printable worksheet
Class 9 · Water Security · 10 Aug 2026
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]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]Match the traditional water bodies from Column A with their primary characteristic or regional context in India from Column B.
[2 marks]| Column A | Column B |
|---|---|
| 1. Pushkar Lake | a. Sacred natural/artificial lake in Rajasthan |
| 2. Dal Lake | b. Urban lake in Srinagar famous for floating gardens |
| 3. Vembanad Lake | c. Longest backwater lake in Kerala used for boat races |
| 4. Lonar Lake | d. Eutrophic crater lake formed by a meteorite impact in Maharashtra |
Answer: __________________________________________
Match the water pollutant or condition in Column A with its primary health or ecological effect in Column B.
[2 marks]| Column A | Column B |
|---|---|
| 1. Mercury in fish | a. Minamata disease |
| 2. Excess nitrates in drinking water | b. Blue baby syndrome |
| 3. Untreated sewage | c. Waterborne cholera and typhoid |
| 4. Thermal pollution | d. Reduction in dissolved oxygen solubility |
Answer: __________________________________________
Match the water pollution prevention strategy with its correct description:
[2 marks]| Column A | Column B |
|---|---|
| 1. Rainwater Harvesting | a. Capturing rooftop runoff to recharge groundwater and reduce runoff volume |
| 2. Nutrient Management | b. Optimizing fertilizer application timings to prevent agricultural runoff |
| 3. Bioremediation | c. Using specific microbial strains to degrade organic pollutants in drains |
| 4. Tertiary Treatment | d. Advanced filtration to remove residual nitrates and phosphates from STPs |
Answer: __________________________________________
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]A _____ is a traditional stepwell found in arid regions of western India, designed to reach the underground water table.
[1 mark]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]Define a Baoli (stepwell) in the context of medieval Indian water architecture.
[1 mark]State the primary environmental objective of installing an Effluent Treatment Plant (ETP) in chemical manufacturing industries across Gujarat.
[2 marks]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]Explain how a *Khadin* system works in the Thar Desert to support both agriculture and moisture conservation.
[3 marks]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]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]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]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]Identify the standard geological zones in a cross-section showing a well penetrating an unconfined aquifer.
[2 marks]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]