Springs are water flowing or seeping out of an opening in the ground or hillside.
The groundwater travels through a permeable layer, on top of a hard or impermeable layer. Usually springs show up where this hard layer is exposed such as at a bank or on a slope. Springs are particularly sensitive to seasonal changes in groundwater availability and may dwindle during dry periods. Since springs are close to or at the ground surface, they can become contaminated when barnyards, pastures, sewers, septic tanks or drainfields are located above or near them. Surface water runoff can carry pollutants long distances where they can come into contact with spring sources.