No abstract

The development of water supplies from wells was placed on a rational basis with Darcy's development of the law governing the movement of fluids through sands and with Dupuit's application of that law to the problem of radial flow toward a pumped well. As field experience increased, confidence in the appli cability of quantitative methods was gained and interest in developing solutions for more complex hydrologic problems was stimulated. An important mile stone was Theis' development in 1935 of a solution for the nonsteady flow of ground water, which enabled hydrologists for the first time to predict future changes in groundwater levels resulting from pumping or recharging of wells. In the quarter century since, quantitative groundwater hydrology has been enlarging so rapidly as to discourage the preparation of comprehensive textbooks. This report surveys developments in fluid mechanics that apply to ground water hydrology. It emphasizes concepts and principles, and the delineation of limits of applicability of mathematical models for analysis of flow systems in the field. It stresses the importance of the geologic variable and its role in governing the flow regimen. The report discusses the origin, occurrence, and motion of underground water in relation to the development of terminology and analytic expressions for selected flow systems. It describes the underlying assumptions necessary for mathema tical treatment of these flow systems, with particular reference to the way in which the assumptions limit the validity of the treatment. � � � 77 THEORY OF AQUIFER TESTS Unit cross-sectional area A. ARTESIAN AQUIFER Unit cross-sectional area Water table B. WATER-TABLE AQUIFER FIGURE 18 .-Diagrams for coefficient of storage. of the angle of inclination of the water table. The product of the last two factors is the component of head change acting normal to the aquifer surface. The importance of interpreting correctly the phrase "component of head change" which appears in the definition of the storage coefficient cannot be overemphasized. Examine figure 18B, which depicts, in schematic fashion, a horizontal

History of municipal groundwater supply________________________ Previous investigations.________________________________________ Methods of investigation.______________________________________ Well inventory.__________________________________________ Geologic mapping________________________________________ Test drilling_______________________________-___-___-_-_-Water sampling___________________________________________ Well-numbering system..__________________________________ Acknowledgments _____________________________________________ Physical features__________________________________________________ Topography_ ________________________________________________ Drainage _____________________________________________________ Climate ______________________________________________________ 11 Geologic formations and their water-bearing characteristics _____________ 11 General geology, stratigraphy, and structure ______________________ 11 Pre-Cretaceous crystalline rocks.

The Green Bay area, which includes parts of Brown, Outagamie,

Contamination of fresh‐water supplies by the disposal of oil‐field brines occurs on a small scale in Alabama. The problems that exist, however, are symptoms of potentially serious problems in the management of oil‐field wastes. The sources of contamination are: 1) evaporation pits and 2) leaks in pipelines or well‐head connections to disposal wells. The storage capacity and construction of many pits are inadequate for the evaporation of the quantity of brine they receive. Waste overflows during rainstorms, affecting vegetation in surrounding areas. Some of the brine overflowing from the evaporation pits or percolating to the water table from the pits or leaks in pipelines moves to the nearest stream. The base flow of some streams in the oilfield areas is maintained by highly mineralized ground‐water inflow. Pits should be used only if: 1) the pit is constructed in an area underlain by semi‐impermeable material, and 2) the storage capacity and construction of the pits is adequate for the quantity of brine and storm runoff they receive. The elimination of contamination from leaks in pipelines and wellhead connections can be accomplished through an effective system of monitoring.