Surface-water sources: Identify the incorrect option. Which of the following is <em>not</em> considered a surface-water source for municipal supply?

Introduction / Context:
Classifying sources correctly guides both intake design and treatment selection. Surface waters and groundwaters typically differ in turbidity, pathogen risk, and dissolved solids content, leading to different treatment trains.

Given Data / Assumptions:

• Standard hydrologic source definitions.
• Municipal-scale supply context.

Concept / Approach:

Surface-water sources include flowing streams/rivers and impoundments/lakes. Springs, however, are fed by groundwater emerging at the surface. While a spring discharges to the surface, the source classification remains groundwater, not surface water.

Step-by-Step Solution:

Verification / Alternative check:

Standard water-supply texts and regulatory definitions categorize springs under groundwater. Treatment objectives often reflect typical groundwater characteristics (low turbidity, higher hardness) rather than surface-water pathogen profiles.

Why Other Options Are Wrong:

• (a), (b), and (d) are canonical surface-water sources.
• “None of these” cannot be correct since one option is indeed not a surface source.

Common Pitfalls:

• Assuming that anything visible at the surface is a surface-water source; the provenance matters.

Final Answer:

Springs.