Deforestation can lead to runoff of water, it does not imply contamination.
Particulate matter of natural origin would be processed by decomposers, increasing nutrients in the soil and in groundwater (if leaching takes place).
Acid precipitation can change pH and mineral composition in the soil, It does not have a direct impact on groundwater.
Answer: leaking underground storage tank is a way of pollution that definitely have an impact on groundwater.
