ALBERT

Notes: New sanitary landfills are being opened each day to accommodate the rising volume of solid wastes. Selection of proper sites is a very major part of the disposal problem, particularly as they might affect the surrounding surface and ground water.Leachate production is inevitable in the humid East and throughout most of the country. Several alternatives are suggested that would result in the assimilation of migrating leachate into, the environment at tolerable limits or for its renovation prior to final discharge: Alternative 1—knowledge of existing hydrogeologic conditions which would favorably control the rate and direction of leachate migration; Alternative 2—engineering the landfill by construction of low-cost facilities to collect and treat leachate; and Alternative 3—construction of limited collection facilities to supplement natural conditions.It is suggested that more emphasis be given to hydrogeologic factors in the selection of refuse disposal sites to insure protection of surrounding surface and ground water. It is time to approach the waste disposal problem on a more sophisticated level by requiring test drilling, monitoring, and by giving consideration to the engineering of, landfills so that man's health and' environment are not jeopardized.

Notes: A simple and rapid method of determining casing length and permeable zones in wells tapping bedrock can be useful to well drillers and hydrologists. A device consisting of a galvanometer, a reel of insulated wire, and a copper electrode locates the casing depth, changes of lithology, and permeable zones. The small-diameter electrode permits measurement through well-seal access ports avoiding the expensive and time-consuming procedure of removing the seal and drop pipes to measure casing depth with a magnet. The measured electromotive force changes rapidly when the electrode passes the end of casing. Thus, the depth of casing is easily determined from the length of wire payed out. Changes in electromotive force measured within the uncased part of a well frequently indicate permeable zones, thereby aiding in choice of the most efficient drop-pipe length, and also yielding useful information for hydrogeologic studies.

Notes: The best features of analog and digital computers were combined to make a management model of a stream-aquifer system. The analog model provides a means for synthesizing, verifying, and summarizing aquifer properties; the digital model permits rapid calculation of the effects of water-management practices. Given specific management alternatives, a digital program can be written that will optimize operation plans of stream-aquifer systems. The techniques are demonstrated by application to a study of the Arkansas River valley in southeastern Colorado.

Notes: Underground detonations may produce observable effects in surrounding aquifers and wells. The nature and the duration of the effect at any observation point seem to depend on several factors such as the amount of energy released by the detonation, the geologic environment, the position of the buried explosive device in relation to the saturated zone, aquifer characteristics, and the distance from point of detonation. Precise measurement of these effects in wells presented numerous technical problems and resulted in the development of specialized techniques. Initially, these effects were observed by measuring the fluctuation of the free water surface in wells. The current technique employs high-resolution pressure transducers deep in the water column. Pneumatic packers may be used to restrict the movement of water into the well. Data are recorded on high-speed oscillographs.

Notes: Present ground-water use in Ohio, approximately 650mgd (million gallons per day) amounts to about 5 percent of the water that enters the ground-water reservoirs. The largest ground-water supplies are developed where natural concentrations of water occur, chiefly in the watercourse aquifers, which consist of sand and gravel of glacial origin (outwash) in the valleys of the major streams. Other important aquifers are glacial outwash in upland areas and in the buried Teays Valley system, the limestone and dolomite aquifers in western Ohio, and sandstone and shale aquifers in the eastern half of the State.Future outlook is that more of the increasing water demand will be met from ground-water sources. Ground-water supplies will be developed at many new sites, and aquifers in areas already heavily pumped will be made to yield more water by the drilling of additional wells and recharging the aquifers artificially. Large quantities of ground water in storage, virtually unexploited, could be used for temporary low-flow augmentation of streams. Management of ground-water resources will be needed to help solve supply and distribution problems, and to resolve conflicts between users. Among future problems will be those arising from underground disposal of wastes, a practice which is expected to grow substantially from enforcement of water-quality standards for streams, set under the Federal Water Quality Act of 1965.

Notes: Pumping test data from a single well were used to estimate aquifer volume affecting drawdown. After four days of pumping from a 240 feet thick welded tuff aquifer in southern Nevada, the volume of the wedge-shaped mass tested was estimated to be about 15.6 billion cubic feet (440 million cubic meters). The field coefficient of permeability of the aquifer is 275 gallons per day per square foot.

Notes: In Southern California's San Bernardino Valley a unique experiment is being performed by a local water district, the State government, and a private industry. Both the experiment and the organizational arrangements for getting the job done are the subject of this paper. The experiment is the application of systems analysis technology to water resource management. The organization is formed by a combination of contracts and cooperative agreement between private and government agencies. The result is a favorable environment for the development of effective water resource management strategies.The San Bernardino Valley is similar Co many areas in the world where water resource management reduces to the allocation of locally available ground water and potential imported water resources. This paper outlines in detail the analysis tools and long-range planning needs of effective ground-water management strategies.

Notes: Coal mining in Appalachia has degraded both the surface and ground water. During mining, ground water is drained from the rocks and the pyrite associated with the coal beds is exposed to air. Oxidation of the pyrite produces high iron ana sulfate concentration and a low pH in the water. Some of this polluted water flows directly into nearby streams and some moves into the ground-water system. When the latter occurs, the iron concentration can increase up to several hundred mg/1 and the sulfates to over one thousand mg/1. Unfortunately, in most cases the cessation of mining does not stop the ground-water pollution, and it can take many decades before the ground water again becomes usable.A detailed study of the effects of coal mining on ground water was conducted in the Toms Run drainage basin in northwestern Pennsylvania where coal mining and oil and gas well drilling have occurred for almost 100 years. The rocks of Mississippian and Pennsylvanian Age produce a multiaquifer system–three major aquifers separated by siltstone and shale beds (aquitatdes). The oil and gas wells act as a conduit system permitting acid mine drainage to move downward from the strip mines to underlying aquifers. It then moves laterally down dip and discharges as springs. The acid mine drainage adversely affects the ground-water quality by increasing the iron and sulfate content of the water especially in the vicinity of the strip mines.

Notes: The measure of earth resistivity is a possible means of detecting and outlining zones of ground-water contamination where a resistivity contrast exists between contaminated and unconcaminated ground water.As a preliminary evaluation of the use of electrical resistivity for defining zones of contaminated ground water, five sites on Long Island and three sites in western Texas were examined. The surveys at three of the Long Island sites and at one of the western Texas sites were at least partially successful in their objectives. The lack of success at the other sites is attributed to the particular physical conditions that existed.Further effort toward developing electrical resistivity as a method for evaluating variations in ground-water quality is encouraged.

Notes: A two-dimensional, passive element electric analog model was used to determine the spatial distribution of natural ground-water recharge in the Santa Cruz River basin of southern Arizona. Existing records were used to draw a ground-water level contour map of the area in its undeveloped condition. The model was made to duplicate these contours by varying inputs from known locations of recharge. Recharge distribution as determined by the model was consistent with previous estimates, but no direct correlation was found with the contributing drainage area.

Notes: The tidal efficiencies of wells tapping the principal artesian aquifer in Glynn County, Georgia decrease with distance from the influencing tidal body and also decrease with well depth. Although the magnitude of water-level fluctuation of these wells is largely dependent upon the distance to a large tidal body, the time of a high or a low water level in the wells is mainly dependent upon the time of a high or a low tide in a small, nearby tidal body. A modified formula for computing tidal efficiency is developed:〈displayedItem type="mathematics" xml:id="mu1" numbered="no"〉〈mediaResource alt="image" href="urn:x-wiley:0017467X:GWAT24:GWAT_24_mu1"/〉 From this formula, tidal efficiency can be calculated rapidly and easily

Notes: Water-supply problems in Spain have become acute during the past decade owing to expansion of industry, construction of modern houses and apartments, and development of a tourist industry. A training program in ground-water hydrology and geology was established three years ago in Barcelona to help supply personnel who would be able to cope with these problems. Training is also given to foreign nationals, a total of nine countries having been represented to date. Part of the success of the school rests on the fact that a large variety of ground-water problems exist in the vicinity of Barcelona. Students obtain a firsthand knowledge of sea-water intrusion, aquifer-testing techniques, agricultural and municipal degradation of water quality, and drilling and exploration techniques within a wide variety of rock types.

Notes: A well-designed and calibrated orifice meter is an accurate and inexpensive measuring device for flow. Endline orifices can be calibrated at work sites by solving an equation that interrelates easily measured dimensions of the orifice and outflow.

Notes: Expanding water requirements during recent years have intensified development of the productive sedimentary aquifers of the North Carolina Coastal Plain. The effects of this development emphasize the local and regional limitations of the aquifer system and the need for an effective management program.Withdrawal of about 60 million gallons per day from the Castle Hayne limestone, the most productive unit of the principal artesian aquifer of the area, began in July 1965 at a phosphate mine adjacent to the Pamlico River in Beaufort County. Within a few months, the artesian head was lowered below sea level in an area of about 800 square miles, and to more than 100 feet below sea level in the immediate vicinity of pumping. Under these conditions the aquifer became vulnerable to encroachment of saline water from (1) areas of natural occurrence of brackish water in the limestone member of the aquifer; (2) leakage of brackish surface water through the confining beds; and (3) vertical movement of brackish water from the underlying sand member of the aquifer.The dramatic and “overnight” effects of the large withdrawals at the mine site and the threat of damage to the aquifer created sufficient public concern so that legislation was passed by the 1967 General Assembly, giving the Board of Water and Air Resources authority to regulate ground-water withdrawals as needed to protect the aquifers of the State. An adequate management program can be accomplished that will not only protect the aquifer but will improve the development potential. The development of such a management program requires a thorough knowledge of the hydrology of the aquifer system, the objective of studies in progress. The implementation of the program will require the support of an informed public.

Notes: The planned development of an individual water supply from a group of wells must take into consideration several controllable and uncontrollable factors. The uncontrollable factors may include aquifer coefficients of transmissibility and storage, aquifer boundaries, static water level, aquifer depth, recharge capabilities, and competing users. The controllable factors often include the acreage allocated to ground-water development, well locations, and pumping rates. Well-field design is oriented mainly toward proper selection of the controllable factors.Water requirements, the cost of water and the life of the well field are related to limitations of acreage, draw-down of water level, and investment in pumping and transmission facilities. All of these factors, in turn, are influenced by the location of individual wells with respect to one another.Well-field design calculations involve the combined interference of water level drawdown among the various wells in the field. Repeated computational trials for various numbers of wells and well spacings may be required. Calculations using conventional methods are, in most cases, rather time-consuming.The final design decision can be approached quickly if it is assumed that the wells have regular spacing. Through the use of a simple formula and table developed in this paper, a given well-field problem can be calculated in a few minutes with a slide rule. When well spacing deviates appreciably from the regular spacing assumed, the final design calculations should be made with computer techniques.

Notes: This article contains a summary of a few disease out-breaks caused by ground-water contamination, and the difficulties in designing and monitoring for effective quality control. There is a discussion of problems associated with large basin recharge with treated sewage. For instance, do we have adequate microbial indicators? Or will the nitrate concentration build up if there is a semiclosed circuit involved? Chlorination of well water withdrawn for domestic use is advocated as good insurance for microbial control.

Notes: A new design method for deep well dewatering systems is given. The method analyses three dimensional flow to the multiwell systems by considering the two end points to the initial fast phase of water table fall. The method is applied to a dewatering case history and proves to be successful.

Notes: A new method of determining aquifer storage coefficients has been developed for use in operations involving ground-water recharge through wells. This work evolved from a research project dealing with the fate of DDT and nitrate in the Ogallala Aquifer in the High Plains of Texas.A tritium tracer was used to determine the detention time of the recharge water passing through a saturated volume of the aquifer. Tracer behavior was formulated ‘mathematically and verified by model simulation. The formulations provide a graphical solution for the detention time from which the storage coefficient may be calculated.The method will have immediate value in establishing storage coefficients of aquifers, such as the Ogallala, where plans for importation and distribution of supplemental water involve utilization of underground storage. Regarding water-table conditions, this method promises to produce more reliable storage values than have been obtained from pumping tests.

Notes: The frequency distribution of dissolved-solids content of ground waters in geologically and climatologically homogeneous terrane units commonly approximates a log-normal distribution. A graphic logarithmic transformation is de-scribed which permits rapid calculation of approximate values for the mean, standard deviation, and coefficient of variation. Statistical parameters calculated by this method show good agreement with known physical conditions in the terranes studied and are precise enough for use as a mea-sure of variability of quality of ground waters for national planning purposes.

Notes: Photogeologic study has been useful in the location of ground-water sources in the state of Sao Paulo, Brazil, and could be important to the investigation of water resources in other areas.Until 1963, it was believed that large areas of the state were unsuited for the location of ground-water wells (as in pre-Devonian crystalline formations) and others weregenerally considered too hazardous (Paleozoic and Tertiary: sandstone lenses in shales). Since that time, when aerial photographs of the whole state became available, the authorhas verified an earlier hypothesis of his own that there are actually very few areas in the state which do not have suitable locations for water wells, and that photogeology is a most valuable method of prospecting.The water sources are parts of highly developed fault/ fracture systems which are identifiable on aerial photo-graphs, at least in this warm humid climate with dry season. Over the fractures the rocks are deeply decomposed, the debris are removed in the rainy season, and existence of water in the dry season promotes higher and denser vegeta-tion along aquiferous fractures, which usually are located in deep straight-line valleys. Even where competent beds are overlain by more than 100 m of unconsolidated strata, many discontinuous nets of parallel straight-line segments are detectable probably because all fractures are really faults with significant throw.To be most effective, the method requires stereoscopic study of areas having dimensions on the order of 10 × 10 km. The selection of locations for drilling should be sup-ported by analyses of the dip of fracture planes (hade) and by other geological-geophysical methods, especially by subsoil electrical resistivity surveying.

Notes: The purpose of this paper is to stimulate additional interest in the hydrogeologic aspects of the International Hydrological Decade (IHD) program and to urge the full cooperation and participation of hydrogeologists in the research and educational activities of the Decade. The IHD, 1965–74, will strengthen the scientific base for water use and conservation, stimulate education and training in hydrology, and improve the ability of developing and developed countries alike to cope with their water resources problems. UNESCO provides an international intergovernmental umbrella and the Secretariat for IHD. More than 90 Member States of UNESCO are participating in IHD and a majority of these have established National Committees for IHD.The UNESCO/IHD program will consist primarily of activities of participating countries themselves, catalyzed, coordinated, and supplemented by international intergovern-mental agencies and scientific associations. Activities of Member States of UNESCO include: collection of basic data through data analysis and applied hydrology; applied and basic research; continental and global water balances and the global hydrological cycle; establishment of hydrological networks and the development of technical competence; fundamental research; definition of principal hydrological features of countries such as precipitation, discharge of water, sediment and dissolved load, evapotranspiration, distribution of tritium in precipitation, surface and ground waters; experimental basin studies to provide insight on the interplay of environmental and hydrological parameters in a broad range of geological, climatic, and ecological conditions; distribution of water in the atmosphere, in lakes and rivers, underground, in permanent ice and snow and permafrost; studies of the rate at which water moves through the hydrologic cycle; use of orbiting satellites and remote sensing instruments for measuring phenomena in the atmosphere and at the Earth's surface and for relaying observational data; organization of egional advanced training and study courses and hydrological institutes; exchange of teams of experts, exchange of professors and research scientists; and organization of symposia and regional seminars.The US/IHD program focuses on the following five major objectives: (1) large-scale balances of water and water-borne material studies; (2) hydrological performance of river, lake, and ground-water basin systems studies; (3) studies of specific hydrological processes and their variations in time, and improvement of methods and techniques; (4) education and training; and (5) services providing coordination and administration support. These objectives provide a framework within which the scientific and engineering community can contribute to IHD. A provisional US/IHD program statement identified, among others, the following hydrogeologic activities: estimation of ground-water discharge to the sea, effects of variations in piezometric head on land subsidence, hydrology in limestone areas, radionuclide tracer studies, chemical behavior of ground water, and dispersion in moving ground water.Hydrogeologists are urged to submit proposals concerning activities for possible inclusion in the US/IHD program. The following seven criteria guide the formulation and inclusion of activities in the US/IHD program by the U. S. National Committee for IHD: (1) the activity is sufficiently fundamental or aimed at results so useful that it will interest all hydrologists; (2) the activity requires joint or coordinated work in two or more countries; (3) the activity concerns a problem whose solution and verification would be improved by work in two or more countries; (4) the activity concerns continental, hemispheric, or global phenomena or processes; (5) the activity requires action in international areas such as polar regions, international waters, and multi-national basins; (6) the activity involves the hydrologic use of earth-orbiting satellites; and (7) the activity involves intercountry exchange or visits of personnel (in some instances, the exchange or visit itself may be the main item of interest). Proposals may be of projects already in progress, for expansion or modification of on-going projects, or for new work. Proposals may be submitted as contributions, requiring no financial aid from or through the IHD; for endorsement by IHD as an aid in obtaining financial aid elsewhere; or, when funds become available, as IHD projects receiving financial assistance from the IHD. Further information may be obtained from: U. S. Na-tional Committee for the International Hydrological Decade, National Academy of Sciences, 2101 Constitution Avenue, N. W., Washington, D. C. 20418.

Notes: A type-curve method for determining anisotropy of unconfined aquifers, developed from electric analog simulation, is applied to drawdowns observed near, a well pumping from a glacial outwash aquifer at Piketon, Ohio. The coefficient of vertical permeability, P z'averaged 365 gpd per square foot. Computed drawdown for the pumped well, based on this value, differed by only a small amount from the observed drawdown. The coefficient of storage, determined from type curves for an image well system, averaged 0.20, typical of unconfined aquifers. Application of the method required a thorough knowledge of geohydrologic controls operating at the test site.

Notes: Criteria and factors are considered which affect the design of a Hele-Shaw viscous flow model for use in ground- water studies. Procedures and construction techniques for assembling such a model are outlined. Some of the advantages and drawbacks in using a viscous flow model are discussed, Three examples are used to demonstrate the use of the model

Notes: A nuclear (atomic) explosive, detonated at suitable depth below the land surface, appears to offer substantial advantages and economies as a tool in the development and management of water, under certain special hydrologic situations. It is appropriate, therefore, that we seek to understand not only the potentials, but also the limitations of such a detonation. This paper is a first, small step toward that end.Greatly over-simplified, what does an underground nuclear detonation do that it can become a tool of water development and management? Consider first a detonation at a depth sufficiently great that none of the products vent to the atmosphere. Minimum depth for such “containment,” in feet, is close to: 〈displayedItem type="mathematics" xml:id="m1"〉1〈mediaResource alt="image" href="urn:x-wiley:0017467X:GWAT13:GWAT_13_m1"/〉in which W = explosive energy, in kilotons.

Notes: In this short paper, selected water quality problems and the research efforts aimed at their solution supported under P. L. 88–379 (the Water Resources Research Act of 1964) at State Water Research Centers are presented. The water quality problems and associated research efforts presented are not necessarily of high priority with respect to the national needs for water quality knowledge; rather, the problems and research discussed are presented as typical of local or regional situations and as examples of the awareness of State Water Resources Research Centers to the local or regional needs for improving water quality management.Selected water quality problems associated with urban- ization, modern agriculture, industry, recreation, and natural environments are discussed with respect to the needs for new knowledge leading to improved management of water resources. Selected Water Resources Research Centers' projects with the objectives of discovering some of that new knowledge are discussed with respect to the research approach adopted by the investigators.

Notes: Maximum yields from minimum aquifers can be accomplished only by strict adherence to best known practice procedures while following the three necessary steps to well completion. These steps are well design, well construction and well development.In well design good practice begins with an accurate log and the obtaining and careful testing of formation samples. From such data, optimum depth, diameters, screen settings, and gravel pack gradations for expected yields can be selected.Well construction should incorporate equipment suited for the kind of formation, size of well, and depth to be drilled. It should be operated by competent and reliable personnel capable of faithfully maintaining all specifications and finishing in a reasonable time, with a well in which all measurements shown on the log are correct.Development techniques which are appropriate for the well, aquifer, and drilling equipment should be used, al-though it appears the high velocity horizontal jetting tool, used in conjunction with chemicals and regulated pumping, offers the most promise.

Notes: The nature and extent of movement of ABS (alkylben-zenesulfonate) and other sewage components through natural soils were studied in the laboratory and in the field north of Denver, Colorado. Small amounts of ABS and bacteria pass through soils and reach the zone of saturation, where they move laterally down-gradient several thousand feet. Total dissolved solids show little fluctuation during such movement, possibly because extracted solutes are replaced by other solutes leached from the soils during water infiltration.In laboratory studies Denver sewage-plant effluent was filtered through packed columns of 8 types of soils. ABS was not significantly removed by most of the soils; how-ever, muck, greensand marl, and residual basalt soil ini-tially removed up to 94 percent of the ABS. Some ABS was removed only after development of bacterial slime on the soils; subsequent infiltration caused leaching of the slime and its adsorbed ABS and other constituents. All soils initially removed about 90 percent of the bacteria within a few feet of travel, but a small percentage passed through the soil. Bacterial clogging occurred quickly in the fine soils but only in modest amounts in the coarse sand, even after three months of flow.Field studies included analyses of river and irrigation water contaminated from a sewage-plant effluent, and well water from selected sites down-gradient between unlined irrigation ditches and the river. Concentrations of ABS and bacteria were significantly reduced during infiltration of irrigation ditch water to the water table. As noted in the laboratory the concentrations of both of these contaminants can be reduced through soil filtering action. In addition there may be some dilution of the infiltrate by the ground water. Dissolved solids showed practically no change between the ditches and the wells.

Notes: An analysis is presented for the nonsteady state problem of a well, pumping a constant discharge, and located at the center of a circular aquifer surrounded by a radial discontinuity. On either side of the discontinuity, the transmissibility and the storage coefficient are constant but may have different values from those on the other side of the discontinuity. The solution is obtained by using an approximate inversion formula for Laplace transforms. This method leads to a relatively simple set of equations which commonly requires only short computer time for solution.

Notes: The growing number of ground-water research projects that are based primarily on potential distribution data has stimulated the development of several new types of potential measuring, instruments. The primary requirements for these instruments are longevity, precision, sensitivity, and short timelag. Ease of installation, minimum maintenance, low capital investment, and provision of a continuous record are equally desirable. Generally, available instruments will satisfy two or three, but not all of these requirements.The need for a piezometer possessing all these characteristics was encountered during a flow-system study beneath an irrigated field. A piezometer subsequently was designed which combines the sensitivity of a Kecke electrical water-level sensing device with the continuous record provided by a Stevens Type F, graphic recorder. Replacement of the standard Keck sensing “Bob” with a probe specifically designed for small diameter pipes (5/16-inch I.D.),* provides instrumentation with a short timelag. The absence of a diaphragm and strain gauges enhances longevity. The device is inexpensive, simple and easily installed. Samples of well water for chemical analysis may also be obtained from the piezometers.

Notes: In a steady-state condition the lateral flow rate through the unsaturated zone of an unconfined aquifer increases with a decreasing rate as the depth of the unsaturated zone increases while hydraulic gradient is kept constant. This flow rate reaches a maximum as the depth of the zone is increased. This maximum flow rate is computed by various methods such as an aquifer model, graphical integration of the characteristic hydraulic conductivity curve and a flow net diagram. Based on these calculations a simple method is outlined for estimation of steady-state flow rate through the unsaturated zone of an unconfined aquifer. It is also concluded that in shallow unconfined aquifers the contribution of the flow through the unsaturated zone to the total lateral flow can be significant.

Notes: The need for a Federal role in the water resources development of the United States was recognized early in its history. The 20th century has seen a dramatic acceleration of activity in the water resources development field, with a concomitant increase in Federal participation. By 1960 the need for coordinating the many Federal programs in water planning and related resources development became apparent. A Senate Select Committee on National Water Resources was formed. The Committee's report was the basis for the Water Resources Research Act of 1964 and the Water Resources Planning Act of 1965. The objective of the Water Resources Planning Act is to provide for optimum development of water resources through the Water Resources Council and several River Basin Commissions, and by providing financial assistance to the States in order to increase State participation in water resources planning. A Council report on the Ohio River Basin will be published soon; this should be followed by the Missouri Rivet Basin report before 1970. The completion of reports for all major river basins has been scheduled for the mid 1970's. These framework studies include population, economic development, and water supply and water use data projected as far as the year 2020. The Water Resources Council also prepares a biennial assessment of the adequacy of supplies of water necessary to meet the requirements in each water resource region in the United States. For this purpose a river basin model is being prepared to determine probabilities of deficiencies and quality requirements in 300 basins, and economic concepts for determination of optimum water use alternatives are being incorporated in the model. Another assignment to the Council under Title I of the Water Resources Planning Act is the preparation of guidelines for all Federal participants in comprehensive regional water planning, and for the formulation and evaluation of Federal water resources projects of all types. The Council also is working on specific proposals for improved floodplain management. Title II of the Act authorizes the President to establish river basin commissions at the request of one or more States and with concurrence by the Council. Title III provides a basis for increased participation by the States in water planning by granting of matching funds. All but two States are now taking part in the State Grant program.

Notes: A preliminary geohydrologic survey was carried out in the Lower Shire Vailey, Malawi, Africa in the summer of 1967. The valley is part of: he East African Rift System. In order to develop more adequate knowledge of subsurface conditions, a reconnaissance gravity survey was performed. The survey showed that potential aquifer material over much of the valley was too chin to support high yield irrigation wells. In addition, when combined with hydrochemical data the survey disclosed a high probability of water contamination by brines circulating upward along fault systems.

Notes: A review of the literature and a study of a number of field tests shows that the presently used analysis and interpretation of step-drawdown tests can be misleading. The efficiency of a well is defined. The usefulness of the step-drawdown test is outlined and a hypothesis for reduction in specific capacity is offered.

Notes: Use of this material will assist in the determination of cost of pumping water, given the quantity of flow required, the total pumping head, the wire-to-water efficiency, and the unit cost of power.A table of conversions is presented to aid in reducing theoretical equations to simplified equations, and a figure is provided for graphical solutions of the equations.

Notes: The consultant expects the driller to provide good data and competent performance. Exchanges of views associated with drilling and construction can prove to be mutually beneficial. Contacts between the consultants and the drillers have a tendency to upgrade the quality of the basic datacollected. These contacts may aid the driller in delivering full performance and thus improve the overall quality of thedrilling and construction he performs for the client. As a result, everybody associated with the water well industry-drillers, consultants, and clients - stands to gain by these contacts. It is hoped that these beneficial contacts within the water well industry will become even more common in years to come so we all can gain from one another's knowledge and experience.

Notes: A graduate program in hydrogeology is described, in which the field is defined as encompassing the whole range of processes operating in water and water-mineral mixtures at and near the earth's surface. The interdisciplinary character of this training is insured by requiring both a minor from another department and course work in other sub-disciplines of hydrogeology in addition to the one in which the thesis is carried out. The importance of nonscientific aspects of hydrogeology is recognized by allowing for minors in fields such as economics and business administration.

Notes: The Colorado Assembly passed three laws in 1965 concerning water rights. Two of the new laws pertain directly to ground water and take cognizance of the fact that some wells divert water that would otherwise reach a stream. The use of ground water is now regulated under the doctrine of prior appropriation, which has applied to the administration of surface water in Colorado since 1852. Under the doctrine of prior appropriation, the first person to make beneficial use of water establishes a right to use that water even when there is a shortage of water for later appropriators.This paper discusses the new laws as they relate to hydrologists and others concerned with hydrology. The law sets up administrative processes for implementing the use of water but raises many questions. Proper hydrologic investigations are necessary as a technical base for administration of the laws.

Notes: Measurements of ground-water recharge in sand drift aquifers in northern lower Michigan show that winter and spring precipitation provides a major portion of the annual water yield. In general, the accumulation of snow beneath forest canopies varied inversely with crown density during the winters of 1962 and 1963. Pine plantations with crown densities of over 80 percent in winter had 1.8 inches less water in the snowpack than neighboring deciduous forests, at the time of maximum accumulation. Ground-water recharge during the melt period was proportionally lower beneath the pine forests where snow accumulation was least. The difference in snowmelt recharge was a major factor in the smaller annual water yields measured under these pine forests.

Notes: It is the purpose of this paper to call ro your attention the existence of the International Hydrogeologic Map Display and the International Legend for Hydrogeologic Maps, and to encourage those in the USA working in the water resources and associated fields to review these recommendations and forward their comments so that they may in turn be relayed to the next meeting of this international commit-tee. It is requested that any maps following the legend be forwarded for addition to the committee's file and use in the Internationa] Display at the next General Assembly meeting of IUGG.

Notes: The Republic of Korea shares the world-wide problems of water supply variability in time and space - they have too little water at some time and in some places, and too much water in others. Drouth is a recurring threat; floods occur nearly every summer. The floods of July 1965 are reported to have been the most costly in history. The population is increasing at a rapid rate and material things are in short supply. However, the people of Korea are making a tremendous effort to modernize facilities, construct an industrial base, improve agricultural practices, control the rivers and develop water supplies, and in general, improve the standard of living. With a per capita income of about $80 per year, Korea has a long way to go in its climb up the economic ladder, but the people are able, intelligent, energetic and avid for learning and progress. They enjoy one of the highest literacy rates in the Far East, and have a trained core of professionals in most fields, except they lack a trained cadre of specialists in ground-water studies and have very few experienced water well drillers. During the Japanese occupation of Korea systematic ground-water studies were begun, and ground-water development followed soon afterwards. But the limited staff of Japanese geologists employed in the effort returned to Japan at the end of World War II in 1945. In the uncertainty of the next 8 years, which included the Korean War, it was impossible to develop trained manpower and an organization.Presently, there is widespread interest on the part of the Korean Government to develop ground water wherever it may be for such uses as irrigation, industrial supply and development, municipalities, villages, and sanitary rural supply. As a result of this interest the author spent four months in Korea in the fall of 1964 and the spring of 1965 at the request of the Agency for International Development, U. S. Department of State, to review the situation and report on the feasibility of a United States supported effort to help the Korean Government to make systematic studies that would lead to ground-water development, and to any necessary improvement of their methods of hydrologic data acquisition and utilization.

Notes: The digital computer is used on a routine basis in the ground-water program in Kansas for tasks ranging from the listing of water-quality data in tabular and publishable form to statistically and graphically analyzing a mass of data.In the past year a number of computer programs in FORTRAN IV have been developed by Charles O. Morgan and Jesse M. McNellis using an IBM-7040 computer to store, retrieve, and manipulate water-quality data. These programs:(1) Tabulate data at the rate of 40 chemical analyses of water per minute in a format similar to that found in the Kansas ground-water publications.(2) Perform necessary calculations and print Stiff diagrams at the rate of 30 per minute.(3) Perform necessary calculations and print Piper diagrams, including a square modification of the normally diamond-shaped cation-anion diagram, and trilinear diagrams of the cations and anions. The symbol representing the analyses located on the diagrams can be designated by either an analysis number or a geologic unit number. A cation-anion diagram showing the average chemical composition of water for an aquifer can also be printed. These diagrams for 50 analyses can be produced in 1.5 minutes.(4) Plot maps of 42 individual, combined, or calculated parameters obtained from the data cards. These maps can be plotted to any specified scale and for as many as 10 designated geologic units. Computer time involved for one map with 50 plotted points is 15 seconds.It is estimated that the use of these programs will save several man-months during a ground-water study, and the error inherent in the manual manipulation of data is greatly reduced. The present cost for running 50 analyses through the four water-quality programs on the computer is approximately $20.

Notes: In the past 20 years, since 1945, there has been a substantial increase in the application of electric well logging to water wells. In the early days, there were very few water wells being logged, principally city supply wells and other larger commercial wells. Now, it is not uncommon to be called to service water wells of all sizes, even the small back yard well. The well drilling industry is becoming more and more aware of the benefits that can be derived from use of the electric log, and there will almost certainly be an increase along these lines in the years ahead. There are some very good reasons for this growth and acceptance of the electric log, and pointing out some of these reasons and applications of the electric logs to water well drilling is the purpose of this paper.

Notes: This paper is concerned with the development of the application of theoretical aquifer concepts to the administration of water rights from ground-water sources, and exam- ples of the application are given. Kansas operating under the Appropriation Doctrine is applying the rule of priority of right, the first in time is the first in right, to the administra- tion of water rights from ground-water sources. The application is not absolute in that some mutual interference pre-scribed by the reasonable raising and lowering of the water level must be allowed as specified in the law.The application of hydrologic considerations in the administration of problems between individual wells is first given. The scope is then expanded and data presented for the application to large basin development where pumpage is largely from storage, using the current situation in the high plains area of western Kansas for the example.An addition to the normal ground-water basic data collection program called a “Key Well” program is proposed where the key well is a production well. This well is to be fully instrumented to give information on diversion costs and evaluate methods of construction, as well as identify any changes in aquifer characteristics with respect to time.

Notes: Chemical analyses of ground-water samples taken from differing depths in a four-county area in east Texas showed a general stratification with respect to dissolved iron, pH and hardness. On the basis of this stratification the waters of the ground-water reservoir were divided into a shallow zone of oxidation, A; a deep zone of reduction, C; and an intermediate and unstable zone, B, in which waters from above and below are mixed. Ground water from zones A and C generally is almost free of iron, whereas water from zone B generally contains objectionable amounts. This zoning is explained by recent laboratory work and theoretical data on iron in natural waters. Wells constructed to draw only from zones A or C should yield water relatively free of iron.

Notes: During a three-month trial period, 70 million gallons of industrial wastes were successfully injected at moderate pressures into a deep limestone in the westernmost part of Florida. The movement of these wastes is expected to be predominantly southward toward the natural discharge area which is presumed to be far out in the Gulf of Mexico. The limestone lies between two thick beds of clay (aquicludes) and contains 13,000 parts per million salty water. A series of aquifers and aquicludes appear capable of preventing contamination of the overlying fresh-water aquifers.

Notes: The very diverse types of ground-water behavior in carbonate terrains can be classified by relating the flow type to a particular hydrogeologie environment each exhibiting a characteristic cave morphology. The ground water may move by diffuse flow, by retarded flow, or by free flow. Diffuse flow occurs in less soluble rocks such as extremely shaley limestones or crystalline dolomites. Integrated conduits are rare. Caves tend to be small, irregular, and often little more chan solutionally widened joints. Retarded flows occur in artesian environments and in situations where unfavorable stratigraphy forces ground water to be confined to relatively thin beds. Network cave patterns are characteristic since hydrodynamic forces are damped by the external controls. Solution occurs along many available joints. Free flowing aquifers are those in which solution has developed a subsurface drainage system logically regarded as an underground extension of surface streams. These streams may have fully developed surface tributaries as well as recharge from sinkholes and general infiltration. Characteristic cave patterns are those of integrated conduit systems which are often truncated into linear, angulate, and branchwork caves. Free Flow aquifers may be further sub-divided into Open aquifers lying beneath karst plains and Capped aquifers in which significant parts of the drainage net lie beneath an insoluble cap rock. Other geologic factors such as structure, detailed lithology, relief, and locations of major streams, control the details of cave morphology and orientation of the drainage network.

Notes: Four principal trends in ground water are apparent:(1) Increasing use of ground water for domestic supplies. Geohydrologists must learn to quantitatively evaluate the supply under conditions of maximum development, not merely determine the availability of a supply that does not strain the aquifer. (2) Aquifers will be looked to increasingly as possible storage media for surplus flood water, in place of dams and reservoirs. The key here is economics – optimum utilization of resources. The job of the geohydrologist is to do enough research and experimentation to determine when, where, and how ground-water reservoirs can be recharged artificially at a reasonable cost. (3) Saline aquifers will be looked at as sources of water supply. The cost curves of developing new supplies of fresh water are ascending while the cost curves for desalinization are declining, and inevitably they will cross in one area after another. There is a paucity of information on saline ground-water aquifers; hence, the utmost skill must be used in evaluating the resource. (4) With efforts to prevent stream pollution, aquifers will be looked to increasingly as possible storage media for industrial and domestic waste effluents. Control is urgently needed so the effects of waste injection can be predicted, the technology for confining those effects as intended can be developed, and a basis can be provided for a rational decision as to whether waste injection or an alternative use of the chosen aquifer is best for the economy in the long run. However, there is little legal basis for control, and the cost of such control may make the practice unfeasible in many situations.A systems-analysis approach is needed to develop a working model of a given hydrologie and socio-economic problem from which quantitative answers can be given to water planners.

Notes: Pollution of ground water to the point of crisis in Missouri can be eliminated by an awareness of geology, by planning, by adequate funding, and by authority to follow planning. Ground-water pollution hazards are widespread in southern Missouri where permeable soils and cavernous bedrock exist. Pollution in northern Missouri is more localized. All of the pollution in Missouri that we have attributed to geologic features could have been avoided if the polluters–municipal and private–had obtained adequate geologic information, used common sense, and supported waste disposal plans with adequate financing.

Notes: The build-up of American military force in Vietnam has necessitated a massive well-drilling program.Engineering investigations were carried on concurrently with drilling to evaluate various related water resources.Water quality problems including salt-water encroachment existed in many areas.Between July 1966 and September 1967. 48 test holes and 233 successful 8 inch wells were drilled. The average producing well yielded 95 gpm.

Notes: The use of this material will give an estimate of the well and pump costs for projects requiring a given capacity. This is intended only as an instrument for establishing orders of magnitude as a basis for comparisons, and of course does not substitute for detailed engineering studies.Well cost data were analyzed for three categories according to the aquifer tapped: sand and gravel, shallow bedrock, and deep sandstone. In the sand and gravel category, tubular and gravel packed wells finished in the glacial materials above bedrock were considered separately.

Notes: This paper deals successively with some general concepts of scientific communication, with the characteristics of four well-known hydrology journals and with ways in which messages are obtained. The most important conclusion is a rationale for restrained publication.

Notes: Sea-water intrusion into ground-water reservoirs occurs when permeable formations outcrop into a body of sea water and when there is a landward gradient. Intrusion can be controlled by reducing pumping, by increasing supply, or by forming some type of barrier. A pressure barrier has been operated in Los Angeles County, California. Special facilities are needed. Costs of operation are high.The intrusion of sea water into ground-water reservoirs can greatly impair the water-supply systems of local areas adjacent to coastlines and tidal estuaries. Such intrusion is always the result of some activity of man either in trying to improve his environment or in his use of natural resources. Following is a discussion of how intrusion occurs, some ways of controlling intrusion, the results of one project in southern California where intrusion is being controlled, and some examples of related costs.

Notes: Approximately two-thirds of the present population live in the urban environment; by the year 2000, it is anticipated that five-sixths of the population will be urban. The trend of metropolitan growth is not the continued growth of major cities, but rather the expansion in population and size of the smaller suburban communities. The urbanization of the country is reflected in the emphasis on comprehensive water resources development – area-wide and basin-wide planning and management. In some areas of intense urban development the problems of water quality control, recreational use of water, and water for cooling and waste transport have become more significant than problems of adequate supplies for withdrawal. A major share of future water resource investigations will necessarily be directed to the urban environment, where geologic and hydrologic data is needed in urban planning.The general pattern associated with community development–the initial use of ground-water resources by individual systems, to the use of a community well and distribution system, and finally the use of surface-water sources far removed from the urban center–has contributed to the development of the “commodity concept’ of water use. By this attitude the water resource is viewed only in terms of its adequacy as a water supply; waste discharge and recreation uses are being ignored or considered a‘ downstream” problem. This concept is particularly inappropriate when applied in the multicommunity complexes of the metropolitan areas where there is little in the way of a “downstream.” Water problems must be dealt with at the metropolitan level rather than at the individual community level; and not by a proliferation of smaller units of government and public agencies that often overlap and duplicate effort. The nature of the metropolitan complex requires that we think in terms of closed systems involving reclamation and reuse rather than in terms of the open system of withdrawal, use and discharge.

Notes: Most State ground-water programs can be grouped under three headings: basic data collection, answering requests, and research and report writing. In Ohio the staff consists of four geologists, two hydrologists, and one field inspector. Most time is spent collecting basic data and answering requests for assistance.(1) Basic data collection: It is the responsibility of one hydrologist to maintain and coordinate the 150 State observation wells. The field inspector is responsible for seeing that well logs are submitted by well drillers in accordance with State law. The inspector is a geologist who works closely with the drillers; he is also active in the Ohio Well -Drillers Association, and prepares a quarterly newsletter. A highly organized well-log file system is maintained, and there is a field location program whereby well locations are plotted on large-scale maps. A ground-water quality sampling program is in operation. A network of 20 existing production wells in strategic areas was established for observing seasonal and annual changes in ground-water quality. A monthly summary of water-supply conditions across the Scace is published.(2) Answering requests: Of the 2,000 requests answered each year, approximately 80 percent involve domestic wells. The remaining inquiries are from industries, municipalities, schools, developers, State agencies, and various commercial or recreational interests. In answering requests a report summarizing hydrogeology and ground-water availability is prepared. For large ground-water developments that are not State-financed the services of a consultant are recommended.(3) Research: Much research in the public interest is concerned with problems and potential problems in ground-water pollution.

Notes: The States of Nebraska and Kansas are negotiating a compact for apportionment of the waters of the Big and Little Blue Rivers. So that the negotiating officials could allocate the water equitably, the amount of streamflow depletion caused by ground-water withdrawals upgradient from the State line needed to be determined. At the request of the Nebraska officials, the U. S. Geological Survey constructed an electric analog model which could be used to determine the amount of streamflow depletion expected to occur in the next 60 years.The model simulates hydraulic conditions in an area of 7,400 square miles which includes the entire area drained by the Big and Little Blue Rivers in Nebraska. The trans-missibility of the aquifer (Pleistocene in age) ranges from less than 1,000 to as much as 300,000 gallons per day per foot, and the storage coefficient averages about 0.20. The transmissibility values are based on examination of test- hole samples from more than 400 test holes in and adjacent to the basin.Analysis of the model indicates that predicted maximum ground-water withdrawals between 1962 and 2022 will not deplete the base flow of the Big or Little Blue Rivers by more than 5 percent.

Notes: California has an enormous stake in the Colorado River. In the southern portion of the State, 80 percent of the water used is furnished by the Colorado River, and this area needs still more water in the immediate years ahead. But it cannot get more from the natural supply of the Colorado. The river is already over-committed, and California in fact may have to cut back on its present take from that source. This is not the Colorado River in Texas; Los Angeles has gone hundreds of miles to get water, but has not reached that far east-yet.

Notes: A simplified method for determining the coefficient of transmissibility of an aquifer being pumped intermittently is developed by applying Stirling's Approximation Formula to the factorial functions in the Theis and Brown equation for drawdown in a well due to intermittent or cyclic discharge. A table of values of K, a term used in the simplified method, corresponding to the fraction of each cycle during which time discharge occurs is also presented.

Notes: During February and March 1964, the U. S. Geological Survey ran caliper, conductance, and temperature logs on several wells in the Sarasota area. The Florida Geological Survey had previously run gamma ray and electric logs on the same wells. Two flowing wells were selected for packer testing. The two wells are about the same depth, penetrate essentially the same geologic horizons, and are about 16 miles apart. The packers were set in the wells between the producing horizons of the formations penetrated and each of the horizons was tested for head, amount of production, and quality of water. One of the tests produced excellent results, indicating that the various producing zones were effectively isolated by the packers and that different quality of water, quantity of water, and a different head was available from each zone. The other test did not show sharp differences but did indicate the extent of contamination of the producing horizons in a flowing well which had been capped for approximately two years. These tests indicate that packer testing can measurably add to knowledge of the separation of permeable zones.

Notes: Quicksand is no myth, nor is it a rare phenomenon, either on the surface or in the subsurface. There is probably quicksand in every State of the U.S.A. where enough gradient is available to produce upward moving ground water. Surface quicksand is likely to occur in hilly country, especially in regions of calcareous rocks which often con-tain solution openings and favor the occurrence of springs. It is often present near stream banks and stream beds, either along their shorelines, under water, or occasionally in the bottom of an apparently “dry” river.Subsurface qurcksand rs found in loosely consolidated or uncemented alluvial, fluvio-glacial, or lacustrine sediments, which are usually well sorted and clean. It has been reported to depths as great as several hundred feet, and from a few feet to as much as 200 feet thick.In water wells, a “quick” or “heaving” condition may exist (as much as 150 feet) if a confined, permeable, loose silt, sand or gravel stratum is continuous to distant higher ground, and is subject to a greater head of water existing at the higher elevation, i. e., if artesian conditions exist.Similar material may heave in a water-table (unconfined) well, due to the natural tendency of granular materials to move toward a drill hole when lateral support is removed (the drill cuttings). Heaving results from a loss of shearing strength as pressure is reduced when a drill hole upsets natural equilibrium. Suction produced by suddenly withdrawing bailer or tools further contributes to disturbing natural conditions.Quicksand is commonly sand (usually fine to medium grained) with an effective size ranging from less than 0.001 inch to 0.005 inch. It is often finer than sugar, which has an average effective size of 0.008 inch, to which it is often compared by drillers. Stoke's Law explains why fine, round- ed grains become “quick” much more readily than coarser sand or gravel.If sufficiently permeable, quicksand aquifers can successfully be used for water supplies, providing proper screening devices are available. However, representative driller's samples; sieve analyses; choice of(or omission of) sand filter pack; proper slot selection; low (0.1 fps) en- trance velocity; and careful, patient development techniques are important prerequisites.Permeability of quicksand varies widely, but might range from approximately 50 gpd/ft to 800 gpd/ft, and average between 100 or 175 gpd/ft2. From a 5-feet thick quicksand bed, and at shallow depths, 1 to 10 gpm may be obtained for domestic or farm supplies using screened wells and drive points. Sufficient yields (250 gpm or more) for municipal wells are also possible.Drilling and completion problems with cable-tool wells can usually be overcome by: 1) watching casing alignment; 2) running bailer slowly; 3) keeping a continual high head of water inside casing; 4)using a heavy string of drill tools; 5) allowing controlled sand-heaving; 6) using short casing drives; 7) jetting with high-pressure water to wash-free tools if seized by a sudden heave; 8) avoiding thin-walled casing; 9) drilling with a mixture of bentonite or native clay and water sludge; and 10) casing above the surface if the well is flowing.Rotary drilling and completion problems are minimal, but unless unusual pressures are encountered, quicksand aquifers may be overlooked. Caving can be prevented by providing sufficient hydrostatic differential pressure, and by using a heavy weighted drilling fluid.Well screens can be set by bailing them down through a quicksand “plug” which may have formed, and completing using the standard pull-back method. A self-closing bottom (washdown fitting) can also be used to jet-down a screen while utilizing a high-velocity water flow.In some cases a sand filter-pack surrounding a continuous-slot well screen may not be advisable in quicksand, especially if the aquifer's effective grain size is approxi-mately 0.004 inch. A naturally developed well completed with a screen having a slot as narrow as 0.005 inch may be preferable, allowing 50 to 60 percent of the aquifer to be developed slowly and carefully through the screen. A case history comparing two well design methods is presented.Both cable-tool and rotary sampling methods in quick- sands are discussed. The techniques are basically similar, whether the material is “quick” or stable.

Notes: A map should treat the critical problems in a way understandable to the intended reader. Some maps appropriately show only one or two pertinent hydrogeologic parameters. Point-data maps make little or no interpretation of the data. Four-dimensional maps-those that include an elapsed span of time or projection of hydrogeologic variables into the future-represent a high degree of interpretation of data; they are most useful to the map reader. The hydro-geologist has an obligation to his reader to design maps that are as useful as possible.

Notes: A simplification of the two most commonly used methods of network planning and scheduling is ideally suited to the planning and evaluation of both water resources studies and construction projects. The project planning diagrams illustrate the system for scheduling of project activities and the relation of each activity to the others.

Notes: The Deep Tunnel System planned by the Metropolitan Sanitary District of Greater Chicago will provide flood and pollution control for the combined sewer areas of the Chicago region. Elements of the Deep Tunnel System that are of main concern to the ground-water resources of the area are the conveyance tunnels and the mined storage reservoir which will convey and store polluted storm-water overflows. The Silurian and the Cambrian-Ordovician aquifers, in units of which these elements will be located, will be protected from any deleterious effects of the System by ensuring that a positive hydraulic head, causing an inward flow, is continuously maintained around the tunnels and the mined reservoir. In the Cambrian-Ordovician aquifer, this necessitates1 that ground-water levels are maintained by artificial recharge. Extensive ground-water studies were conducted to (1) demonstrate the feasibility of aquifer protection by recharge, (2) determine the needed amounts of recharge water, and (3) estimate the seepage of ground water into the tunnels and mined res.ervoir. The studies included field investigations, analog computer analyses and office evaluation of the collected data and analog results. The results indicate that (1) the proposed aquifer protection is feasible, (2) the recharge requirements will vary from 1.4 mgd in 1976 to 6.0 mgd in 2010, (3) seepage into the tunnels will be small, in amounts that can be easily controlled.

Notes: The project developed between the U. S. Army Corps of Engineers, Office of Appalachian studies and the U. S. Geological Survey for a study of the ground-water resources in Appalachia had two principal objectives. The first objective was to describe in general terms the ground-water resources of the Region as a whole and the second objective was to describe in greater detail the ground-water resources at about 20 selected sites. This paper deals with the methods used to describe the Region as a whole, wich a special emphasis on availability and cost of developing ground water, as was requested by the Office of Appalachian Studies.

Notes: The standard water-level indicator can be easily and inexpensively modified so that it also measures casing lengths. The simple modification permits electrical current from one wire of the two-wire probe to be routed through the metal casing. The semiquantitative method works well with most metal casings, including nonmagnetic ones, and can be used to detect most casing reductions. The method is limited in that it works only below the water level in the well, and in that it cannot easily detect casing reductions when the conductance between the upper and lower casings is low.

Notes: In this paper a way of estimating the probable character of the water in sand aquifers is explained with examples. Comparative chemical quality of water from many types of sand formations generally encountered during drilling may be predicted with considerable accuracy by observing the color of an aquifer sand and its depth. This approximate method of “guessing” water chemistry, if properly used, can do much to guide the water well contractors. It may often fail due to incorrect application of the technique rather than a failure of the technique.