Which of the following is not typically found in surface water?

High mineral content is not typically a characteristic associated specifically with surface water, as it varies greatly depending on many factors such as geographic location, weather, and geological conditions. Surface water is usually more influenced by atmospheric conditions and land use than by the mineral composition found in groundwater, which can have higher mineral levels due to natural processes like leaching from rock formations.

In contrast, algae are commonly found in surface waters, particularly in warmer months when conditions are favorable. Heavy metals can also be present in surface water due to runoff from industrial activities, urban areas, and other sources. Organic pollutants, such as pesticides and pharmaceuticals, often enter surface waters from agricultural runoff or wastewater discharge. Understanding that high mineral content is generally more characteristic of groundwater than surface water helps clarify why it is the correct answer to the question.