However, this accessibility also means that it is easy to detect any pollution, as well as clean up any problems. Groundwater is the opposite. Because it is generally protected by thick deposits of soil and rocks, it is harder to contaminate than surface water. But then it is also harder to detect any pollution, and very difficult indeed to clean up the problems. There are new ways to clean up contaminated groundwater, but they are all costly and time-consuming.
Prevention is the key to maintaining clean, healthy supplies of water.