Difficulty: Easy
Correct Answer: Storage reservoirs
Explanation:
Introduction / Context:
Classifying sources correctly is essential for choosing intake structures, treatment steps, and protection measures. Underground (groundwater) sources supply water that has percolated into aquifers, while surface sources are open to the atmosphere and typically require different treatment approaches.
Given Data / Assumptions:
Concept / Approach:
Groundwater emerges naturally (springs) or is abstracted artificially (dug wells, tube wells, infiltration wells/ galleries). Storage reservoirs, however, are surface impoundments formed by dams or barrages and are not underground sources.
Step-by-Step Solution:
List bona fide groundwater sources: wells, springs, infiltration wells.
Recognize storage reservoirs as surface water bodies.
Hence the incorrect listing under “underground sources” is “Storage reservoirs”.
Verification / Alternative check:
Protection strategies differ: groundwater emphasizes sanitary seals and wellhead protection; reservoirs focus on catchment control and algal management—reinforcing the classification difference.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
Storage reservoirs.
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