Which of the following is a common groundwater contamination source?

• A. Leaking underground storage tanks
• B. Ocean currents
• C. Wind erosion
• D. Glacial deposition

Answer: (A)

Groundwater contamination often starts with leaks from underground storage tanks. These tanks store fuels and solvents; over time the steel or other materials can corrode, seals and joints can fail, or improper installation allows liquids to seep into the surrounding soil. Once these contaminants reach the subsurface, they move with groundwater, forming plumes that can travel toward and into aquifers and drinking-water wells. Substances like gasoline components are especially problematic because they dissolve in water and persist as they’re carried by groundwater flow.

Ocean currents affect surface seawater rather than groundwater, wind erosion is a surface process that removes soil, and glacial deposition shapes landscapes through sediment movement—not a typical pathway for dissolved contaminants entering an aquifer.