The availability of surface water for swimming, drinking, industrial or other uses sometimes is restricted because of pollution. You can either build the library then link to it from subsequent projects, or you can include specific GAlib files in each new project that you create. Think about what you had for lunch. A hamburger, for example, requires water to raise wheat for the bun, to grow hay and corn to feed the cattle and to process the bread and beef. They may run a variety of geophysical tests on the completed hole, keeping and accurate log of their observations and test results. Source: Hydrology: The Study of Water and Water Problems A Challenge for Today and Tomorrow, a publication of the Universities Council on Water Resources Sources and more information.