Which statement about groundwater is true?

• A. A Groundwater has no mineral content
• B. B Groundwater temperature fluctuates wildly
• C. C Groundwater often has stable temperature
• D. D Groundwater is always easier to locate than surface water

Answer: (C)

Groundwater tends to have a stable temperature because it is sheltered underground, with heat transfer dampened by the surrounding soil and rock. This insulating effect means that, at typical depths used for drinking-water sources, the temperature changes very little over the year, unlike surface water that heats up in the sun and cools at night or seasonally. That stable temperature also influences the chemistry and microbial activity within the aquifer. Minerals dissolved from the surrounding rocks are common in groundwater, so it is not mineral-free. Temperature of groundwater does not swing wildly, and whether groundwater is easier to locate than surface water depends on local geology and hydrogeology rather than a universal rule.