Groundwater pollutants are the same as surface water pollutants: municipal, agricultural, and industrial. Groundwater is more susceptible to some sources of pollution. For example, irrigation water infiltrates into the ground, bringing with it the pesticides, fertilizers, and herbicides that were sprayed on the fields. Water that seeps through landfills also carries toxins into the ground. Toxic substances and things like gasoline are kept in underground storage tanks.
Groundwater is a bit safer from pollution than surface water from some types of pollution because some pollutants are filtered out by the rock and soil that water travels through as it travels through the ground or once it is in the aquifer
When the pollutant enters the aquifer, contamination spreads in the water outward from the source and travels in the direction that the water is moving. This pollutant plume may travel very slowly, only a few inches a day, but over time can contaminate a large portion of the aquifer. Many wells that are currently in use are contaminated.
Groundwater is susceptible to pollutants that infiltrate into the ground from underground storage tanks or agricultural fields.
Rock and soil filters some pollutants as water travels down to and through an aquifer.
A plume containing pollutants travels outward from the source and through the aquifer in the direction the water is moving.