Which term refers to water that contains little or no salt and is suitable for most uses, including drinking water?

• A. Surface water
• B. Groundwater
• C. Nonpoint source pollution
• D. Freshwater

Answer: (D)

Freshwater describes water with low dissolved salts, which is what makes it suitable for most uses, including drinking. The key idea here is salinity—the amount of salt dissolved in water. Freshwater has very little salt, unlike seawater, which is high in salinity.

Surface water and groundwater are kinds of water sources; they can be freshwater, but they’re categorized by where the water is found, not by how salty it is. Nonpoint source pollution is about how pollution enters water (diffuse sources) rather than the salt content of the water. So the term that best matches “water that contains little or no salt and is suitable for drinking” is freshwater. Keep in mind that even freshwater sources often require treatment to remove contaminants and pathogens before drinking.