Activities on the land's surface - including sewage pollution, solid waste pollution, oil and gas pollution and runoff from agricultural chemicals can adversely affect the quality of groundwater, the drinking water for about 50% of the US population.
(Activities on the land's surface - including sewage pollution; can adversely affect; the quality of groundwater, the drinking water for about 50% of the US population)
Activities on the land's surface - including sewage pollution
can adversely affect
the quality of groundwater, the drinking water for about 50% of the US population