ABSTRACT
According to McGuiness (1969), the hydrogeologist’s work has many facets and has changed with time. What does the hydrogeologist see as the de˜ciencies in knowledge that are his responsibility to remedy? At one time he had a rather simple job. He mapped the geology of his study area or re˜ned mapping done earlier by others. He gathered as much information as he could on the depth and productivity of wells, the kinds of rocks they penetrated, and the chemical characteristics of the water they yielded. He interpreted these data in terms of the different geologic units. Ultimately, he prepared a report, maps, and charts showing where and at what depths water could be obtained, and in a general way, how much and of what quality. For rocks not penetrated by enough wells in his area to yield reliable information, he extrapolated information from other areas where similar rocks were better known, according to his experience and his familiarity with the data and published literature. This procedure was considered acceptable and suf˜cient in the early days of hydrogeologic studies. As groundwater development progressed and water demands became larger, the hydrogeologist found it necessary to think in quantitative terms about the permeability and storage coef˜cients of the aquifers and the effects on groundwater levels of pumping increasing amounts of water from more closely spaced wells.
