ALBERT

Notes: Entrenchment and subsequent filling of a glacial valley have led to localization of iron-enriched ground water in the Silurian carbonate aquifer at the Vistron plant, Lima, Ohio. All production wells are open exclusively to the carbonate aquifer. Water from the saturated glacial deposits of relatively low permeability and high ironcontent is drawn laterally into the more permeable carbonate aquifer containing water with relatively low concentrations of iron. Wells closest to the saturated glacial deposits yield water with iron concentrations greater than 1.4 milligrams per liter. These wells, in the southwestern part of the site, apparently form a sink preventing iron-enriched water from migrating into other pumping wells in the central and northern parts of the area.Iron concentrations have not increased in individual wells between 1971 and 1981. They are not expected to increase in the central and northern wells as long as about 20% of the plant's ground water is withdrawn from at least two of the southwestern wells.

Notes: Nitrate-N concentrations during the Summers of 1980 and 1981 exceeded 10 mg/1 in 68 of the 164 ground-water samples collected from a shallow water-table aquifer underlying a sand plain near Alliston, Ontario. Three extensive zones of nitrate contamination were associated with major potato-growing areas on the sand plain. Nitrate concentrations were positively correlated with both the percentage area of heavily fertilized crops (potatoes, corn, sod and asparagus) and nitrogen fertilizer application rates in the vicinity of ground-water sampling sites. Chloride levels in ground water exhibited a positive association with KCl fertilizer application rates. Ground water under potato fields had relatively consistent C1/NO3-N ratios despite considerable variations in nitrate-N and chloride concentrations. Ground water with a low nitrate content was found beneath forest and permanent pasture. These data suggest that the use of commercial nitrogen fertilizer is a major source of nitrate in the aquifer.

Notes: Abstract. A simple and convenient method for calculating two-dimensional dispersion on a TI 58 or 59 programmable calculator utilizing the normal distribution program available in the Solid State Software Master Library module as a subroutine is presented with an example.

Notes: Three simplistic models are developed for evaluating the transport of organic pollutants through soil to ground water. The models consider mobility and first-order degradation. The first calculates linear sorption/desorption of the pollutant and first-order degradation without considering dispersion. The second is similar to the first but also considers dispersion. The third considers nonlinear sorption following a Freundlich equation and first-order degradation but does not consider dispersion. The models are compared to field data for the pesticides aldicarb and DDT. The models projected a lower mobility for DDT than was observed in the field.

Notes: Darcy's equation and unsaturated-flow theory are used to calculate flow through earth linings that are placed in ponds or channels to reduce seepage. The procedure utilizes the relation between unsaturated hydraulic conductivity and pressure head of the underlying material as calculated from the measured saturated hydraulic conductivity and the relation between water content and pressure head. The method enables the selection of the liner (thickness and hydraulic conductivity) that will keep seepage below a certain maximum limit. Since the hydraulic conductivity of clays is affected by the cationic composition and the salt concentration of the soil solution, the chemical composition of the liquid moving through the liner must be taken into account. This applies also to other chemicals, including solvents and other organic compounds that may be in the water. Travel times of water from the surface impoundment to the underlying ground water are calculated from the seepage rate and the corresponding water content in the vadose zone. Accumulation of solids (mine tailings, for example) can further reduce the seepage from the pond. Proper design of waste-water ponds also requires analysis of the response of the underlying ground water (mound buildup) and the movement of pollutants in the vadose zone and aquifer. In view of the high costs of earth liners, prediction of the seepage is necessary to make sure that the selected lining material, the thickness of the liner itself, and the method of construction will produce the desired results.

Notes: A multidimensional, finite-difference model for ground-water flow and heat transport is used to analyze the thermal energy storage experiment conducted by Auburn University in Mobile, Alabama. The experiment consisted of three stages–namely, injection, storage and recovery occurring for 80, 51 and 41 days, respectively. This application demonstrates the validation evidence that the model adequately and accurately simulates the field experiment. The numerical model includes the effects of: hydraulic anisotropy, thermal convection and conduction, and heat loss to the adjacent confining strata. Observed aquifer isotherms at the end of each stage are compared with predicted values on a cylindrical grid situated about the well. The degree of vertical discretization used in the model is shown to impact the predicted temperature profiles at each stage, but has minimal effect on the recovery water temperature.

Notes: The author has used the concept of depression cone volume to derive type curve equations for large-diameter wells in aquifers of finite extent. Comparisons with the corresponding type curves in an infinitely extensive aquifer have been given. These solutions are based on joint exploitation of the ground-water movement equation (Darcy's law) and the continuity equation for large-diameter wells.

Notes: The majority of well fields in the river region in the Netherlands, where anaerobic water is withdrawn from the shallow aquifer, have problems with well clogging. In order to test the supposition that sulfate-reducing bacteria play a role in this clogging process, sulfate-reducing bacteria in water from wells on well fields with and without the occurrence of clogging were enumerated. In water withdrawn from nonclogging wells, the Most Probable Number of sulfate-reducing bacteria averaged 5 per 100 ml, whereas in wells subject to clogging, the number averaged 25 per 100 ml. A statistical analysis by Wilcoxon's order test confirmed that a significant difference exists between the numbers of sulfate-reducing bacteria in clogging and nonclogging wells. The mechanism whereby sulfate-reducing bacteria contribute towards this type of well clogging is as yet unclear.

Notes: The Kansas Geological Survey is pursuing an effort to automate some of the more common methods of aquifer pumping-test analysis. This paper discusses the results of work done on the leaky artesian aquifer as defined by Hantush and Jacob (1955). The paper covers the basic theory of the aquifer type, the numerical solution of the leaky artesian-well function, and the methodology of achieving the “best fit” parameters in the least squares' sense. Several data sets are used to demonstrate the applicability of the proposed technique. These examples indicate the generally satisfactory results produced by the automated analysis documented here.The algorithm has good convergence properties. Initial estimates for the aquifer parameters may vary by about three orders of magnitude above or below the correct values. For typical data sets the rms fitting error should be less than a few tenths of a foot. If this is not the case, one is probably not dealing with a simple leaky aquifer. This method of pumping-test analysis does not eliminate the role of an experienced hydrologist to define the local hydrogeology and aquifer type. However, once the decision is made as to which aquifer configuration is being observed, this program will, in a quick and unbiased fashion, give an accurate assessment of the leaky-aquifer parameters within the limits of the theoretical approximations and the data quality.

Notes: The software for simulation of the three-dimensional ground-water flow, developed by Trescott (1975), is executable only on bigger machines with large memory capacities. To popularize the sophisticated software for easily accessible small machines, the organization is restructured and various programming facilities are availed. The new design is tested with an earlier quoted example. The program requires about 11K bytes of memory as against 72K bytes of the original program on IBM/370. The methodology borne out of the present work to implement large programs for small computers is presented along with the modified code.

Notes: In the design of ground-water heat pump systems the quantitative analysis of heat transport and heat storage is of great interest. A unified finite element approach to the transient nonlinear heat transport and heat storage problem is presented. The theory presented includes nonlinear physical properties and boundary conditions, coupled conductive and convective heat flow, freezing (phase change), and time-dependent heat input and output. The given theory is applied to two problems. The first problem is a transient study during a few years of heat storage in saturated clay. A pure conductive theory is used due to the small amount of convective water flow in clay. The second problem deals with transient heat transport in an aquifer according to coupled conduction-convection theory on a one-dimensional model problem.

Notes: The principal water-bearing units (in descending stratigraphie order) in Pipeline Canyon are the alluvium, the Dilco Coal Member of the Crevasse Canyon Formation, the Torrivio Sandstone Member of the Gallup Formation, and the Upper and Lower Gallup Sandstones. Presently, the alluvium is recharged by a perennial, southward-flowing stream sustained by mine dewatering discharge in addition to natural precipitation and runoff. Localized infiltration has created ground-water mounds in the alluvium. Artesian conditions may exist in sandstone units which are adjacent and hydraulically connected to the alluvium in these areas. Basement faults have produced the Fort Wingate and Pipeline Canyon lineaments which intersect in the area of investigation. Fault-related fracturing of the sandstones allows for significant ground-water recharge via the overlying alluvium. Flow in the sedimentary formations is generally to the northeast, while the alluvial system flows to the southwest. The natural water quality for the aquifers in the area is dominated by sodium and sulfate ions. However, complete characterization of the natural water quality is complex because of ground-water contamination by acidic tailings fluids from a local uranium mill.

Notes: This paper describes a systematic and straightforward method for the estimation of velocity components in three dimensions from hydraulic head data. Groups of four measurement points are connected to form tetrahedrons, and a linear interpolation scheme is used to obtain a head gradient estimate for each tetrahedron. Application of Darcy's law then yields the desired velocity component values. A sample calculation and comparison between this method and a two-dimensional approach are also included.

Notes: Two earthfill sections of Wallace Dam on the Oconee River near Eatonton, Georgia were constructed with vertical drainage filters (chimney drains) in a clay fill zone. In order to evaluate the performance of the filter in the west dike of Wallace Dam, the finite element Galerkin method was utilized in formulating a numerical model to study the steady-state saturated-unsaturated seepage characteristics through the earth dam. The resulting model is applied to Station 58+00 of the west dike of Wallace Dam. Numerical results for the four cases analyzed in this study describe the location of the zero pressure isobar and total hydraulic head values ranging from 425 feet (130 m) to 365 feet (111 m). Model results indicate a maximum seepage velocity of 2.62 feet per day (0.80 m/day) using a saturated horizontal hydraulic conductivity of 0.283 foot per day (8.64 cm/day). A maximum seepage rate is calculated to be 0.266 cubic foot per second (7.52 × 10−3 m3/sec). Analysis of the hydrostatic uplift forces along the base of the dam indicates an average pressure head reduction of 51 feet (16 m) from the upstream to the downstream side of the dam. Comparison of local seepage velocities to the critical seepage velocity upstream of the filter and inside the filter indicate a factor of safety against piping (a factor of safety against a quick condition arising in the soil) ranging from 0.3 to 3.7.

Notes: The ground-water observation well network in many parts of Kansas has been developed and expanded through the years without serious attempt to determine the adequacy of the network for any specified purpose or to assess its cost effectiveness. This study was undertaken to examine the existing well network in northwest Kansas and to determine the arrangement that offers the most satisfactory accuracy for the purpose of monitoring it. To achieve this goal, we have employed the theory of regionalized variables to estimate the amount of spatial variability of the water table. The error analysis produced by universal kriging indicates that a significant reduction in the number of wells could be achieved by employing a regular 4-mile (6.4-km) network, without affecting the present level of accuracy. It also indicates that it is not practical to reduce the estimation error in the water-table surface uniformly throughout the region because to do so would increase the cost of monitoring wells drastically. For example, reducing the presently existing error by 50 percent throughout the area would require 16 times more wells than the currently existing well network.

Notes: In river basins where aquifers are closely interrelated with a stream, large-scale ground-water development can lower water tables near the stream and diminish stream flows. Junior surface right holders are adversely affected. A digital computer simulation of the hydrologic-economic system on the lower South Platte River in Colorado is employed to study economic impacts of two water management policies. Open access management is found to yield high income benefits but imposes substantial costs on surface-water users when water supplies are limited. Incorporation of ground water into the appropriation system can help avoid the losses to surface-water users, but greatly reduces the income of ground-water users.

Notes: Basalts are a major source of ground water throughout the Columbia River Plateau region of the Pacific Northwest. Development and management of ground water in these basalts are complicated by the spatial variability of the hydrologic characteristics of the deep, stratified lava flows, but new irrigation developments and municipal and industrial water needs are placing increasingly larger demands on the ground-water resource. Water management decisions are aided by individual basin studies that contribute to greater understanding of the regional ground-water system. A distributed-system multiple-storage model for the Deschutes River Basin, Oregon, reveals the magnitude of spatial differences in ground-water recharge, storage, and discharge for this watershed. Input-output analysis elucidates the functional characteristics of the basin groundwater system, and it identifies the presence and magnitude of interbasin linkages in the ground-water system. Implementation of ground-water development strategies based on storage and transmission characteristics simulated by the model demonstrates that basin or regional perspectives are necessary to fully utilize ground-water storage in basalts.

Notes: No strategy for countermeasure design or future directions of research in the areas of human behavior which leads to traffic accidents or lifestyle-related diseases can be rationally developed without an acceptable working theory of human behavior in these domains. For this purpose, an attempt has been made to conceptually integrate the available evidence with respect to the role of human behavior in the causation of road accidents. From this integrative effort it would seem that the accident rate is ultimately dependent on one factor only, the target level of risk in the population concerned which acts as the reference variable in a homeostatic process relating accident rate to human motivation. Various policy tactics for the purpose of modifying this target level of risk have been pointed out and the theory of risk homeostasis has been speculatively extended to the areas of lifestyle-dependent morbidity and mortality.

Notes: A probabilistic language based on stochastic models of population growth is proposed for a standard language to be used in environmental assessment. Environmental impact on a population is measured by the probability of quasiextinction. Density-dependent and independent models are discussed. A review of one-dimensional stochastic population growth models, the implications of environmental autocorrelation, finite versus “infinite” time results, age-structured models, and Monte Carlo simulations are included. The finite time probability of quasiextinction is presented for the logistic model. The sensitivity of the result with respect to the mean growth rate and the amplitude of environmental fluctuations are examined. Stochastic models of population growth form a basis for formulating reasonable criteria for environmental impact estimates.

Notes: In 1980, the U.S. Supreme Court vacated a revised occupational standard for benzene, stating that the Occupational Safety and Health Administration (OSHA) had failed to demonstrate that significant health risks existed under the current standard. This decision has been interpreted by OSHA as requiring the consideration of quantitative risk assessments, whenever possible, in the development of regulations for occupational carcinogens. In light of this decision, the available epidemiologic evidence was used to generate a quantitative risk assessment for benzene. Uncertainties regarding the levels and lengths of benzene exposure for the studied cohorts were incorporated into the analysis. Based on the one-hit model, the assessment indicates that a working lifetime exposure to benzene at the current permissible exposure level (10 ppm) poses a substantial excess risk of death from leukemia. This report discusses the calculation of the risk estimates, the basis for relying on certain assumptions, and the inherent limitations of using epidemiologic studies to quantify cancer risks.

Notes: Studies of risk perception examine the opinions people express when they are asked, in various ways, to characterize and evaluate hazardous activities and technologies. This research aims to aid risk analysis and societal decision making by (i) improving methods for eliciting opinions about risk, (ii) providing a basis for understanding and anticipating public responses to hazards, and (iii) improving the communication of risk information among laypeople, technical experts, and policy makers.

Notes: The current fascination with risk acceptability, risk benefit analysis and other devices for relating risk to social gain is a manifestation of the loss of faith amongst certain groups in modern western society with the honesty and competence of those who assess and finally make judgements about public safety. The problem lies as much in a suspicion over the motives of leading personalities and the fidelity of assessment procedures as it does with the collective psychology of individual beliefs and judgements. “Real world” studies involving carefully sampled households monitored over a period of time may well reveal better information on the complexities of risk cognition and evaluation than laboratory investigation of the views of individuals responding in isolation.

Notes: This paper looks critically at the emergence and present status of risk analysis with the aim of assessing its usefulness for policy decisions on risk regulation and the acceptability of risk-bearing innovations. The authors adopt a personal narrative to illustrate their own involvement in risk research and to comment on empirical trends that have resulted in the current fashion for risk workshops. The second part of the paper confronts specific issues in risk research. These are not new problems-indeed several of the questions asked have been taken directly from a list used to structure a recent risk seminar; but the stand taken here is rather less conciliatory than is usual when these issues are discussed. The pessimistic message of this paper is that risk research, especially in the area of risk perception, is being used as a panacea with which to attempt to remedy what are essentially societal and political matters. Risk research is being used as a tool in a discourse which is not concerned with risks per se, nor with the cognitive processes by which people misperceive the risks of new technologies, but whose hidden agenda is the legitimacy of decision-making institutions and the equitable distribution of hazards and benefits. The authors take a subjectivist view, not just of risk but in general, and query the natural science approach to risk perception, with its assumption that universal dimensions of risk perception can be discovered and used in policy-making and setting regulatory standards. Although it is possible to collect subjective data on the wider meanings that risks and benefits associated with technological innovations have for lay publics, the interpretation and recombination of these data into useful policy guidelines is seen as fraught with technical and, above all, political problems.

Notes: Recent concern with the potential for stray carbon fibers to damage electronic equipment and cause economic losses has led to the development of advanced risk-assessment methods. Risk assessment often requires the synthesis of risk profiles which represent the probability distribution of total annual losses due to a certain set of events or activities. A number of alternative probabilistic models are presented which the authors have used to develop such profiles. Examples are given of applications of these methods to assessment of risk due to conductive fibers released from aircraft or automobile fires. These assessments usually involve a two-stage approach: estimation of losses for several subclassifications of the overall process, and synthesis of the results into an aggregate risk profile. The methodology presented is capable of treating a wide variety of situations involving sequences of random physical events.

Notes: It is readily observable that there is a wide gulf between the manner by which the lay public and the manner by which technical experts assess the risks of complex technologies and assimilate these assessments in decisions regarding the acceptance or rejection of technological options. On the public side, this gap in methods and value assessments is a major source of distrust of technical experts and disaffection with the social management of technology. From the viewpoint of the technical experts who introduce or regulate technologies, this gap is both a cauldron of frustration and a perceived justification for paternalistic technocratic decision-making that further alienates important segments of the public. It is the author's belief that unless our society learns how to progress in bridging these gaps within the framework of a comparative mode of risk-cost-benefit analysis of options, the potential net benefits of certain technologies such as commercial nuclear power could well be lost to our society. Research on public risk perception, while potentially an important component in achieving this objective, needs to be restructured from its present static orientation to meet the needs of forward-looking decision-making that accommodates dynamic learning processes of both the public and technical experts as well as the “learning curves” of technological improvements historically accompanying successful innovations. Moreover, no less attention needs to be devoted to improved benefit assessment along with ethical and equity considerations in decision-making involving the reconciliation of conflict between individual and societal interests. This paper examines the vital importance of interdisciplinary analysis in fulfilling these needs.

Notes: It is pointed out that the familiar analytical device of “event tree”, widely used in risk analysis, can be viewed as a transition matrix expressing the likelihood of going from “entry states” to “exit states”. This point of view is shown to have numerous interesting conceptual and computational features which promise to make it a very useful addition to the arsenal of tools for risk analysis. The basic idea is explained first in terms of a simple, made-up example. The application of the idea to a very real and complicated problem, nuclear-plant risk assessment, is then outlined.

Notes: Age-adjusted cancer mortality data (1964) were examined for evidence of independence. Indications were found that substitution of one cancer for another is a common occurrence. The data were interpreted as supportive of the view that natural selection for resistance to cancer in general has occurred with many resistance-related genes common to prevention of cancer of several sites. Consequently, the comparison of age-adjusted incidence or mortality rates of cancer of single sites alone does not provide a satisfactory estimate of the magnitude of an “environmentally induced” cancer risk. It is necessary to examine all causes of death to find indications of a real life-shortening episode.

Notes: A nonparametric estimator of the probability distribution of time-to-tumor is incorporated into an algorithm for calculating linearly extrapolated dosage limits from an animal carcino-genesis bioassay. The procedure is illustrated with tumor data from a mouse bioassay with 2-acetylaminofluorene. Extrapolated dosage limits for an excess risk of 10-6 differ by only a factor of 2 across the six replicates of the experiment.

Notes: Cost/benefit analysis is often an imprecise tool because of assumptions that must be made about matters that are difficult to quantify. The problems become especially acute when lives or serious bodily injuries are at stake because of the serious nature of that which is being risked. Furthermore, the literature on cost/benefit analysis focuses on public decision-making situations and decisions by individuals. This paper examines the distinctiveness of the use of cost/benefit analysis involving putting dollar values on human life by for-profit firms. The argument developed in the paper is that the lack of participation by the affected party (or government representative) in balancing costs and benefits raises special ethical concerns. A formula that was developed by the Ford Motor Company concerning accidents involving fuel leakage and fire with resultant loss of life and serious burn injuries is used as an example of both the imprecision of the method and the distinctive factors of the decision process that raise special ethical considerations. The paper examines why the for-profit-decision is distinct, what the special ethical considerations are, and concludes with a discussion of several alternative procedures to monitor the use of cost/benefit analysis so that it would be an effective business tool while at the same time the individual is provided maximum protection.

Notes: Studies of the hydrogeologic environments and the dynamic and equilibrium relations of fresh and salt water in aquifers have been intensified at several places along the southeastern Atlantic Coast. Some salt-water problems involve the coastal water-table aquifer, and others involve parts of the artesian system.On the sandy coastal islands of North Carolina, freshwater lenses under water-table conditions float on salt water. Salt-water contamination may take place by (1) lateral encroachment from the ocean and bay; (2) vertical encroachment from below; (3) overland inundation by ocean water during storms; and (4) downward percolation of salt spray and salt-bearing precipitation.In the Savannah, Georgia, and South Carolina area, salt-water encroachment along two of five water-bearing zones in the principal artesian (limestone) aquifer has been caused by the decline of artesian pressure due to pumping. Some wells in the limestone at nearby Parris Island, South Carolina, yield salty water when overpumped. From Savannah southward at least to Fernandina, Florida, connate salty water occurs in the artesian aquifer below the fresh water. At Brunswick, Georgia, connate salty water is stratified between fresh-water bodies in the limestone aquifer above depths of 2,000 feet. Connate salty water has contaminated the aquifer between depths of 500 and 800 feet in a small area in the city.Along the southeast Florida coast drainage canals have been the primary cause of salt-water contamination of the highly permeable Biscayne aquifer. Criteria have been established for the operation of salinity-control dams to prevent encroachment. The salt-water front in the aquifer along the coast is dynamically stable under natural conditions.

Notes: In an investigation of a high water-table problem in the west part of Coleman, Alberta, ground-water temperatures were found to vary by as much as 12 degrees F at different points within a one-quarter square mile area. Analysis of their distribution, together with ground-water chemistry, and configuration of the water table itself led to discovery of three distinct sources contributing ground water to the townsite. They are: Cordilleran glacial deposits north of the town, an abandoned coal mine underlying the town, and the Crowsnest River. The permeability distribution showed that a major direction of ground-water movement is along a former course of the Crowsnest River, although the river was channelled to a different location more than fifty years ago.

Notes: A brief statement on Kansas geologic data is given. A policy statement on the application of the Appropriation Doctrine to the administration of a ground-water basin as proposed is described. Examples of present ground-water problems and application of new methods of solution are discussed as they are being used in Kansas. The problem of evaluating the use of present basic data programs and some insight into future basic data needs are indicated in the closing remarks.

Notes: The most widespread potential sources of ground-water contamination in the highly urbanized metropolitan area of northeastern Illinois are individual sub-surface sewage disposal systems (approximately 162,000), dumps and landfills that receive millions of cubic yards of refuse annually, and sewage effluent and industrial wastes discharged into streams that are hydrologically connected with widely used shallow aquifers. Contamination also may be introduced from surface and subsurface storage of hydrocarbon and other soluble or mobile materials and from water of poor quality coming from depth.Ground-water contamination is a problem of regional scope in the urban area of northeastern Illinois. It must be considered in metropolitan planning not only as a hazard to health and safety but as a basic part of the over-all program of development and management of water resources. Contamination can result not only in increased cost of treatment but also in the reduction of water resource potential. The relationships that exist between ground-water contamination and land-use requirements of the area must be resolved in any effective program.Establishment of effective policies to control ground-water contamination in areas of concentrated ground-water use requires knowledge of the nature of contaminants and their behavior in the physical environment. Hydrogeologic criteria must be developed to determine whether the natural environment can adequately safeguard ground-water reservoirs against contamination, and. engineering specifications should be established to provide protection where natural safeguards are lacking.

Notes: Shallow aquifers, commonly the most important sources of ground water, are also those most susceptible to contamination. The mode of entry of contaminants to shallow aquifers is (1) directly, via wells or secondary openings in consolidated rocks, (2) percolation through the zone of aeration, (3) induced infiltration through the zone of saturation, and (4) interaquifer leakage or flow through open holes.Natural removal or degradation of contaminants is by filtration, dispersion, sorption, ion exchange, oxidation, and various biochemical processes. These phenomena are controlled by the physical environment, structure; mineralogy, and hydraulic characteristics of the earth materials contacted by the liquid wastes.When liquid wastes enter an aquifer directly, there is little or no natural treatment by filtration, sorption, or oxidation. Purification is only by those processes that operate within the aquifer under anaerobic conditions. Contaminants from natural sources that enter aquifers under saturated-flow conditions are degraded primarily by dilution. The natural processes effective in reducing contamination from surface-water sources depend on the hydraulic regimen involved, which vary with individual cases.Liquid wastes percolating through the zone of aeration are those most likely to be purified by natural environment processes. Natural processes, however, do not effectively remove or degrade all contaminants, especially some of the many highly stable compounds that have gained widespread use in recent years, such as synthetic detergents. Comprehensive interdisciplinary research into the ability of various earth materials to remove many types of contaminants under varying hydrologic conditions is needed.

Notes: The economics of ground-water resource development and use are discussed. After a consideration of the welfare criteria, problems of defining and managing property rights are presented. The interrelated nature of ground-water use and external effects resulting from uncoordinated individual action lead to inefficiencies in ground-water development and use unless appropriate institutional arrangements have been made.

Notes: Ramifications of contamination are increasingly involved in the majority of ground-water problems. The volume of usable ground water is shrinking in many places because of dispersion of contaminated water. Consideration of ground-water contamination as a multitude of independent problems, separately solvable as each problem arises, is outmoded; wise policies, relating water supply to contamination potential, are needed to alleviate and to forestall problems.Methodology of managing contamination problems calls for appropriate classification of the hydrogeologic environment; these classifications include aspects of interdependent factors such as permeability, sorption, hydraulic gradient, position of water table relative to some base, and distance from source of contamination. Effective evaluations relate the dynamics of the hydrogeologic environment to contingencies involving contamination, as man changes his water-development and waste-disposal practices.Ways of contamination and pertinent parts of the physical environment include: waste-disposal practices (at or near land surface and in deep formations), artificial recharge (at land surface and in aquifers), accidents, and salt-water contamination of aquifers (shallow depth from salty surface water and at variable depths from subjacent salty aquifers).Evaluation of waste-disposal problems calls for appreciation of two opposing tendencies–the tendency of wastes to move with ground water and the tendency to be attenuated near disposal sites by decay or inherent decrease in potency, by chemical and physical sorption, and by dilution through dispersion of ground water. Mixed wastes of differing attenuation habits represent special complex problems.

Notes: Skilled planning is essential to achieve the level of efficiency in ground-water resource evaluation programs which will be required in the future with foreseeable manpower and money limitations. The planning effort must be broader in scope in the future than it has been in the past if ground-water hydrologists are to successfully cope with an expanding number of marginal ground-water development projects. To insure adequate consideration of all factors, planning procedures should provide for reconnaissance type quantitative analyses of ground-water conditions before committments concerning scope and emphasis of the program are made. A substantial amount of careful computation should be included as an integral part of the planning effort.

Notes: Ohio is a good example of a dynamic state, ranking third of all the states in the nation in value added by manufacture; first in the amount of water used by industry; twelfth in cash receipts from agriculture; and fifth in population. With all of this activity the state still relies largely upon a common law system of water rights. The Frazier vs. Browndecision of 1861 held that despite the fact that a hole Jacob Brown dug on his property caused his neighbor's spring to stop flowing, the loss gave rise to no legal action. The court based its decision on older cases where this was the rule for two main reasons: the movement of ground water is secret, and legal restriction would inhibit the development of the state. Considering the costly process of determining the behavior of ground water, to the ordinary landowner, it is still “secret and occult.” Further, abandoning the simple rule of wide-open development in a state as well-developed as Ohio would call for an administrative agency.The Ohio Water Commission, in 1960, presented a proposed bill to create “watershed districts” which could manage new uses of ground water. Agriculture and municipal advisory councils expressed concern that there were no ground-water laws. The industrial advisory council, however, was vigorously opposed to any change in the present water rights laws of Ohio. The bill was unsuccessful.The common law rule in Ohio, though admittedly primitive, still works. The time will come, however, when Ohio will enact a water law. Already one situation has officially placed the handwriting on the wall. When that time comes, the decision will be made insofar as possible by principles of the private free enterprise competitive economy. The theory will be that you can have additional water if you can pay the price. Ohio's state agencies are already looking to artificial recharge, rather than restriction. Agriculture may need some special protection, because it is so vulnerable.

Notes: Relatively simple and inexpensive qualitative hydrologic models have been found by the authors to serve as an extremely effective means of demonstrating the interrelationship of various hydrologic factors and their resultant effect upon each other to persons not familiar with this subject. The models consist of clear plastic tanks mounted on a vertical display board made of plywood. The tanks are connected with hoses. Flow of water is regulated by surgical clamps on the hoses. Vegetable dye is used in the water to differentiate among waters from various sources. The models have been extremely useful in lawsuits related to water supplies which were tried before juries.

Notes: The alluvial deposits that occupy the Madrid Basin in central Spain form an aquifer system covering an area of 5,000 km2 (2,000 mi2) and with thicknesses of 2,000 m (6,600 ft) or more. Average annual precipitation is 500 mm (15 in.) and average annual temperature is 15°C (59°F). The precipitation is sufficient to provide a net surplus to ground-water recharge which, in turn, supports dry weather flow of major streams in the basin. A distribution of surface recharge and hydraulic conductivities were obtained from a previous study utilizing a two-dimensional finite-difference model of the same vertical cross section as this study. In this study a flow net and a discrete-state compartment (or “mixing-cell”) model were employed to calculate the age distribution of ground water circulating through the aquifer. Carbon-14 decay ages were determined for nine ground-water samples taken from eight locations. The ages obtained with the flow net and with the mixing-cell models are mutually consistent and generally agree with the carbon-14 decay ages. The calculated ages range from zero at the recharge boundaries to over 100,000 years at discharge boundaries in stream channels. The results obtained are to be regarded as preliminary. Their principal value will be to guide future C-14 field sampling programs.

Notes: The objective of this study is to demonstrate the application of a predictive ground-water potentiometric-head model to estimate the profitability of irrigation in contrast to that of dry-land farming. Unit cost per acre-foot of water required for a variety of crops is used to determine the distributive impact of predicted aquifer depletion at 5-year intervals during 20 years of simulated pumping. A land-use planning scheme is proposed for identifying areas (one square mile or less) where various crop types can be irrigated based on benefit-cost criteria for two arbitrary pumping rates as well as on future energy and well development costs. Maps showing areas of profitable production are presented for cotton and alfalfa as examples of crops requiring as much as 1 and 2 ac-ft/ac/yr (0.30 and 0.60 ha-m/ha/yr), respectively. Irrigation-water needs and related profitability are presented as examples for several crops by using the model.

Notes: Stable isotope and fluid chemistry investigations in complex hydrogeologic areas have proven useful in delineating the origin of thermal waters and their interaction with local ground-water reservoirs. The application of these techniques is illustrated using water samples collected from all hot and warm springs and many of the wells in the East Shore area, Utah. These samples were analyzed for major cations and anions, oxygen-18/oxygen-16 and deuterium/hydrogen ratios.The data presented suggest the presence of at least two and perhaps three distinct hydrogeologic regimes. One regime involves fault-controlled deep circulation of waters derived from high elevations in mountains toward the east. These waters evolved into the sodium plus potassium, chloride-enriched hot spring fluids that are high in total dissolved salt concentration (greater than 4,000 mg/1), exhibit oxygen-18 enrichment due to geochemical rock-water interaction at depth and have deuterium/hydrogen ratios similar to high elevation mountain springs. A second hydrogeologic regime is comprised of waters derived from lower elevations that infiltrate into the shallow valley sediments. These dilute calcium plus magnesium, bicarbonate fluids comprise most of the area's ground-water supply.Leakage of thermal waters into overlying cooler aquifers is observed in the vicinity of the hot springs, and is believed to occur in several other portions of the East Shore area. These leakage zones make up the third hydrogeologic regime observed in the East Shore area.

Notes: Abstract From flowmeter interpretation studies using wells with no available caliper data has emerged information which is also pertinent to flowmeter analysis in conjunction with a caliper log. A simple method for interpreting flowmeter and caliper log pairs incorporating this insight has been developed. Location of constant-flow regions, inflow and outflow zones is done by manually comparing the shapes of the caliper and flowmeter logs. A flowrate log is then produced using quantitative volumetric flowrates calculated for several depths in the well. The log contains all the significant flow information without spurious noise and would be suitable for converting to an apparent hydraulic conductivity log.

Notes: Elevated arsenic concentrations were found in ground water near Canal Fulton, Ohio. The hydrologie and chemical properties of the area were studied to determine the source of the arsenic and evaluate the possibility of a similar problem occurring elsewhere. Two major aquifer systems exist within the study area: the Sharon Sandstone of the upland areas; and the outwash sand and gravel deposits of the buried valleys. Ground-water flow is generally from the north, but local variations are caused by the Tuscarawas River valley on the south and west of the study area. Within the study area, there is no evidence for an anthropogenic source of arsenic to the ground water. Agricultural soils, abandoned underground coal mines, industrial impoundments to the north, and an abandoned industrial dump site within the study area were all eliminated as possible sources for the arsenic. The arsenic in Canal Fulton ground water is entirely inorganic, consisting of about equal parts of arsenate and arsenite. Reduction-oxidation (redox) considerations suggest that arsenic is controlled by an adsorption equilibrium with ferric hydroxides, and that the reduction of the ferric hydroxides by a recent lowering of Eh and/or pH in the aquifer has liberated both iron and arsenic to solution. A high correlation between ferrous iron and total dissolved arsenic supports this model. It is hypothesized that Eh conditions have been lowered in the aquifer by either the recent introduction of methane gas or the deposition of a thick layer of till during the last glacial retreat. The methane gas could be leaking from deep underground storage at the site and reducing oxidized compounds. The deposition of till would have eliminated local recharge of oxygenated waters.

Notes: Soils underlain at shallow depths (less than 1 m, 3 ft) by glacial till are generally considered undesirable for irrigation because of their unfavourable internal drainage characteristics. In some areas of southern Alberta, Canada, soils developed upon shallow tills have been irrigated successfully for over 60 years with no adverse effects on the soil. An investigation was conducted to describe the hydro-geologic properties of till under one of these areas and to assess the properties with regard to drainage. Study techniques consisted of detailed test drilling and sampling, excavation of test pits, installation and monitoring of ground-water instrumentation, field and laboratory hydraulic conductivity testing and tritium analyses of ground-water samples. Two fracture sets were found in this till. Both sets of fractures produce secondary permeabilities which mask the low hydraulic conductivity of the till matrix (10−10 m·s−1). Small-scale fractures which have a fracture spacing of approximately 10 mm (0.4 in.) have an apparent mean hydraulic conductivity of 5 × 10−9 m·s−1, whereas large-scale fractures which have fracture spacings from 20 mm (0.8 in.) to over 630 mm(2 ft) have an apparent mean hydraulic conductivity of approximately 2 × 10−7 m·s−1. The high hydraulic conductivity of the large-scale fractures was corroborated by tritium analyses of ground-water samples. Tritium analyses also indicate the presence of recent water at depth in the till. The large-scale fractures, which control the bulk hydraulic conductivity of this till, provide conduits through which infiltrating water can be transmitted to the ground-water regime. These fractures are believed to be the reason why this land has remained irrigable for over 60 years.

Notes: In 1977, the Island Water Association (IWA) on Sanibel Island, Florida, was concerned that the total dissolved solids concentrations in several wells in its well field were increasing and might cause the blended raw water to exceed the design capacity of its electrodialysis plant. Test wells were drilled several miles west of the existing well field, and two pumping tests, one at the site of the test wells and the other in the existing well field, were run. Average values for the transmissivity (T), storage coefficient (S), and leakance (K′/b′) of the lower Hawthorn aquifer were determined to be T = 1,290 ft2/d (119 m2/d), S = 2.7 × 10−5, and K′/b′= 7.47 × 10−6 (1/d). The results of the pumping tests and other findings indicated that pumpage from the lower Hawthorn aquifer was being derived from artesian storage in the aquifer and from vertical leakage into the aquifer from adjacent formations. It was estimated that the IWA would be able to recover usable water from the lower Hawthorn aquifer for about 5 more years by drilling new wells in the vicinity of the test wells and in other nearby areas that might be determined to yield usable water. After this period of time, it likely would become increasingly difficult, if not impossible, to obtain large quantities of usable water from the lower Hawthorn aquifer, unless significant quantities of water could be found in areas in which few data were then available. The principal recommendations, which subsequently were acted upon by the IWA, were to conduct drilling and testing in the lower Hawthorn aquifer several miles west of the test wells and to investigate the underlying Suwannee aquifer and deeper zones as possible sources of large quantities of brackish water.

Notes: Slug and bailer tests are being used increasingly to evaluate the hydraulic properties of “tight” geologic units. Although these pulse methods of stressing a system are used typically only on single wells, the repeated pulse method described here stresses the system in the same manner, but the response is measured in observation wells. This type of pulse test yields much the same information as conventional pumping tests, but it is easier to perform in very low permeability units.The observation well response hydrographs are analyzed by curve-matching techniques. In general, a unique set of type curves must be computed for each pulse test. These type curves are computed easily if the pulsed well is treated as a line-source (or sink). The accuracy of the value of transmissivity (T) determined from the line-source type curves compared to using the finite-diameter well solution depends both on the pulsed well radius (rc) and the time interval between pulses (Δt). If TΔt/rc2 is maintained greater than 50, then T determined from the line-source solution will be within 25% of that determined from more accurate, but computationally inconvenient, finite-diameter well type curves.The repeated-pulse test technique was applied to an experimental well array completed in the Conasauga Shale Formation at Oak Ridge National Laboratory. Values of transmissivity determined by the repeated-pulse method agreed well with the results of slug tests performed on each well individually, and in addition, provided information on storage coefficients and anisotropy at the site.

Notes: A large portion of northwest Oklahoma is situated over the Ogallala Aquifer. Economic growth in the region has been tied closely to irrigated agriculture which depends on declining ground-water resources in the Ogallala formation.As part of an integrated six-State study, Oklahoma researchers developed a computer model of the agricultural sector of northwestern Oklahoma and estimated irrigated and dryland cropping patterns, farm output and farm income over a 40-year planning horizon. Projections were made for a “baseline” situation, and the sensitivity of these results to alternative assumptions on energy costs, commodity prices and technological development was also analyzed.Preliminary results of the baseline analysis suggest a favorable outlook for irrigated agriculture in the area through the near to mid-term, with increases in irrigated acreage, production, and returns to land and management. However, the baseline case is dependent on several relatively optimistic assumptions regarding future fuel prices, yields, and agricultural commodity prices. Even fairly large changes in fuel prices and yields are not particularly critical for model results, but if agricultural commodity prices are substantially lower than projected, the outlook for irrigated agriculture in the area is not favorable.

Notes: There are numerous ramifications to consider in discussing water rights and laws. In this discussion meaningful impressions concerning water rights and related laws in the 31 States lying east of Texas and the Dakotas are presented. Research is still in progress and a number of the statements are necessarily tentative./〉Although legislation of various types has been enacted, court-made rules still provide the primary basis for the water rights laws of most eastern States. This means rules developed by the reported decisions of the State appellate courts. In Louisiana, however, unlike the common-law States, the Civil Code provides the primary basis for its laws (see Borton, Mark E. and Ellis, Harold H., “Some Legal Aspects of Water Use in Louisiana,” La. Agr. Expt. Sta. Bul. 537, June, 1960). Bear in mind that these general rules often vary from State to State and that they may be modified by voluntary contractual arrangements, the exercise of eminent domain, prescriptive rights, legislation, and various other complicating factors. Furthermore, the laws of most States are unsettled regarding a number of questions, and several court decisions are of elderly vintage and hence might be modified under current conditions.Water supplies, natural or developed, all may be more or less interrelated. But rights to use them may vary according to their particular designation as classified by the courts for various purposes. Some common classifications of natural water supplies include natural watercourses, diffused surface water, percolating ground water, and underground streams.

Notes: 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.

Notes: If earthquakes are recorded on your water-level charts, you can make your own estimate of earthquake magnitudes! As an aid in doing this, this paper presents two graphs: one to calculate distance from well to earthquake epicenter; the other, a nomogram from which to read hydroseismic magnitude plus log C. Examples given show (1) direct computation of ms+ log C, (2) use of aftershocks to estimate total water-level fluctuation caused by a major earthquake (when the recorder drum has spun around or when reversals cover up the record), and (3) how to determine if aftershocks theoretically should have been recorded. Hydroseismic magnitude is the surface-wave magnitude (Ms) calculated from seismically induced water-level fluctuations in wells. As yet it must be computed indirectly from ms+ log C but because log C is a variable the result is only approximate. Log C is believed to represent a resultant controlled by magnification, period of the surface waves, instrumental frictions, well lag, and resonance if the well is underdamped.

Notes: Ground water, being essentially free of salt and suspended matter, generally free of contamination from chemical and bacterial waste and relatively stable in temperature, is attractive to industries, municipalities, farmers and urbanized society in Saskatchewan. However, ground-water reservoirs are difficult to locate and evaluate and ground water tends to be highly mineralized when compared to surface water. Suspected ground-water reservoirs do not represent a capital asset until they are proven up, at least partially, and catalogued.It is possible that some 2 × 108 million gallons of water are stored in the glacial drift beneath southern Saskatchewan. Pumpage of ground water was about 50 million gallons per day in 1963, or about 1.8 × 104 million gallons per year. If we were to prospect as diligently and as successfully for ground water throughout southern Saskatchewan as we already have to locate 14 million gallons per day around many of our cities, towns and villages, theoretically we should locate another 486 million gallons per day of recoverable ground water.Because present pumpage of ground water is small, the ground-water reservoir in southern Saskatchewan is still essentially full. However, the amount of usable ground water actually recoverable will remain difficult to estimate reliably until we receive more refined information on amounts of ground-water recharge and on the dependable productive capabilities of some of our Province's major aquifers.Most municipal ground-water supplies in Saskatchewan contain total dissolved solids in the order of 500 to 1500 parts per million. Hardness usually falls in the 200 to 900 parts per million range; alkalinity is regularly below 600 parts per million and iron below 6 parts per million. While waters in many aquifers in the lower part of the glacial drift and in the underlying bedrock in Saskatchewan are often very highly mineralized, this water is customarily suitable for stock-watering purposes. There is great need in Saskatchewan for the development of a small-unit demineralizer that is within the budget of the average farmer.Aquifers in Saskatchewan most suitable for development include surficial sand and gravel, sand and gravel in buried bedrock valleys and other sand and gravel within the glacial drift. High salinity, low permeability, customary great depth below ground surface, difficult and costly drilling, and difficult and costly well construction and well development make bedrock aquifers unattractive except for certain types of industries that can use inferior quality water.There is much merit in following a systematic and scientific procedure when trying to locate ground-water supplies. Any sequence of steps or phases followed must consider the elements of economy, quality of work, speed and efficiency. Mathematical and electric analog models are useful when trying to forecast the long-term dependable yields of aquifers under different pumping schemes.

Notes: Coal-tar derivatives from a coal-tar distillation and wood-treating plant that operated from 1918 to 1972 at St. Louis Park, Minnesota contaminated the near-surface ground water. Solutions of phenolic compounds and a water-immiscible mixture of polynuclear aromatic compounds accumulated in wetlands near the plant site and entered the aquifer. The concentration of phenolic compounds in the aqueous phase under the wetlands is about 30 mg/1 but decreases to less than 0.2 mg/1 at a distance of 430 m immediately downgradient from the source. Concentrations of naphthalene (the predominant polynuclear compound in the ground water) and sodium (selected as a conservative tracer) range from about 20 mg/1 and 430 mg/1 in the aqueous phase at the source to about 2 mg/1 and 120 mg/1 at 430 m downgradient, respectively. Phenolic compounds and naphthalene are disappearing faster than expected if only dilution were occurring. Sorption of phenolic compounds on aquifer sediments is negligible but naphthalene is slightly sorbed. Anaerobic biodegradation of phenolic compounds is primarily responsible for the observed attenuation. Methane was found only in water samples from the contaminated zone (2-20 mg/1). Methane-producing bacteria were found only in water from the contaminated zone. Methane was produced in laboratory cultures of contaminated water inoculated with bacteria from the contaminated zone. Evidence for anaerobic biodegradation of naphthalene under either field or laboratory conditions was not obtained.

Notes: In this work, an indirect inverse method utilizing sensitivity analysis is employed to help understand the reasons for model insensitivity. The results of the sensitivity analysis allow the modeler to delineate insensitive areas of the model where inverse procedures will be more subject to error. Sensitivity coefficients are defined and discussed. A differential equation is developed for the sensitivity coefficients that will generally be solved by numerical techniques. A relatively simple least squares' inverse procedure is used on a hypothetical model to illustrate typical problems that can be encountered. In particular, the effect of data accuracy is considered. The low sensitivity areas of models are generally related to small values of δh/δx and δh/δt. The fact that considerable error in the transmissivity and storativity may occur in areas of low sensitivity should not be looked upon as a failing of the inverse procedure. It is simply a fact that not all areas of the model have been stressed equally. The main advantage of the present work is that areas of low sensitivity may be delineated.

Notes: During the past 20 years, hydrologists have made increasing use of isotopes to obtain a better theoretical and practical understanding of ground water. The distribution of isotopic species in water provides information on sources of ground water, on flow paths and mixing, and on physical and chemical characteristics of aquifers.Numerous examples in the literature illustrate the techniques and applications of isotopes to ground-water studies. Isotopes have helped solve problems as diverse as what is a fair tax rate for people using imported water in a California water district, and why Venice is sinking. Demands are increasing for better understanding of hydrologic systems to facilitate management of water as a resource, and to evaluate environmental problems. Thus, we can anticipate isotopes will be used more and more in hydrologic studies.

Notes: The U.S. Geological Survey maintains a computerized ground-water site-inventory (GWSI) file that contains information about wells and springs at sites from all States of the United States. This file contains data collected by U.S. Geological Survey personnel and personnel of cooperating State, local, and Federal agencies. The file is easily accessible to members or users of the National Water Data Exchange. Since the establishment of the GWSI file in 1974, the data base has grown 19 percent per year and contains information on about 770,000 sites as of February 1981.

Notes: Significant savings are frequently achieved from increasing well and pump efficiency by repair or replacement. Replacement analysis (a part of engineering economics) may be used to schedule these actions. The criterion is to maximize net benefits or minimize the cost of water. The optimal timing of repair or replacement occurs when the cost per unit of water from the old system becomes more than the minimum annualized cost per unit of water from the new system.

Notes: In conventional methods of aquifer tests, homogeneous and isotropic formations are assumed. In many instances, however, aquifers are anisotropic. To resolve this problem, three-dimensional flow equations in homogeneous, anisotropic and leaky aquifers are derived. With the equation and method outlined in the report, we can determine the three components of directional permeability (x, y, and z) in the presence of leakage, and determine the statistical distribution of fractures and stream channels. Field tests that verify our theory are presented.

Notes: Abstract Multiple regression analyses produced low R2 values of measured physical and chemical parameters and saturated hydraulic conductivities (K sat) for southern Alberta soils. We concluded that these physical and chemical parameters are inappropriate in themselves for estimating laboratory or field-determined saturated hydraulic conductivities under southern Alberta conditions and that other factors which may exert greater control on K sat (i.e., structure) should be included in the regression analyses.

Notes: In 1905, N. H. Darton described the geology and underground-water resources of the central Great Plains in his classic report that emphasized the importance of the Dakota aquifer to this region of the United States. Since Darton's work, many investigators have studied Dakota-aquifer hydrology with regard to development of local or statewide resources. Preliminary mapping of relatively recent fluid-level data by the U.S. Geological Survey indicates regional potentiometric trends similar to those interpreted by Darton, but altitudes substantially lower in part of the area. The classic artesian-system concept of the Dakota aquifer is not consistent with some of the data and observations of the past several decades. The simple aquifer geometry and effective lateral hydraulic continuity normally associated with that concept do not appear to characterize the Dakota aquifer regionally.

Notes: Large quantities of sludge can be disposed of safely by burial in narrow trenches. This paper describes a study to quantify the amount of buffer area around a trenching operation that would allow for the natural soils to stabilize sludge leachate without threatening the ground-water supplies of surrounding communities. A vertical buffer consists of a thickness of unsaturated soil below the base of the trench. Its thickness is calculated by comparing the cation exchange capacity of the soil with the exchangeable cations in the sludge leachate. Data from metropolitan Washington, D.C. consistently require a vertical buffer of less than 3 feet thick. A minimum of 3 feet of unsaturated soil is recommended as a margin of safety, although no specific studies were performed to reach this value. The horizontal buffer is a strip of land that must be maintained between the trenching operations and the site boundary. Its width can be more than two orders of magnitude greater than the vertical buffer. Its width is based on the nitrogen loading of the soil from the sludge and the mobility of nitrate in the upper aquifer based primarily on hydraulic conductivity and the characteristics of the sludge/soil interaction. An advection-dispersion model predicts nitrate concentrations for various buffer widths, and is used in conjunction with a specified maximum allowable nitrate concentration to determine a minimum horizontal buffer under certain ground-water flow conditions.

Notes: Classification of ground-water systems provides a useful basis for the transfer of hydrologic knowledge from one site to another and for enhancing the public's understanding of ground water. The five features of ground-water systems useful in classification are (1) components of the system, (2) nature of the water-bearing openings, (3) composition of the rock matrix, (4) storage and transmission characteristics, and (5) recharge and discharge conditions. Using these features, the United States can be divided conveniently into 14 regions.

Notes: An experimental test program was conducted to measure the longitudinal permeability of a grouted thermoplastic water well casing system. A neat cement grout, with and without calcium chloride or bentonite admixtures, was placed in the annulus of a simulated well. Test pressure and specimen configuration was shown to influence the measured coefficient of permeability. A neat grout with a water/cement ratio of 2.0 had a much higher permeability coefficient than the same grout with a water/cement ratio of 0.46.Once the bond line between the grout and casing was broken, the permeability of the system was generally higher than for the initial test. Specimens with a bell coupling included had a slightly higher permeability than specimens with straight pieces of casing. The effect on permeability of the admixtures in the grout was not conclusive. However, the addition of a bentonite slurry to the test water was observed to decrease the permeability coefficient when tested under low pressure.The permeability coefficient of the basic neat grout casing system ranged from 20 – 100 × 10 −5 cm/sec at low test pressure. It was concluded that the casing has an impact on the longitudinal permeability of the system since the coefficients of permeability measured were significantly higher than other published values. However, the coefficients of permeability measured were in the range of soils with low permeability such as silts.

Notes: The goal of this study was to provide a preliminary assessment of the occurrence and movement of the pesticide aldicarb in ground water in the Central Sand Plain of Wisconsin. Aldicarb concentrations in ground water beneath three main study fields and two subsidiary fields were monitored during the period December 1980–August 1981. A total of 67 well points, some nested, and one multilevel sampler were installed for this study. In addition, 25 private wells and seven irrigation wells were sampled.The data collected to date are limited both in space and time. However, several trends are evident: (1) highest concentrations of aldicarb were detected in shallow monitoring wells (those located immediately below the water table); (2) no aldicarb was detected in any of the deep monitoring wells (those located roughly 60 feet below the water table), although aldicarb was found in some of the irrigation wells finished at approximately the same depth; (3) aldicarb seems to be concentrated in roughly a 5-foot layer near the water table, and (4) marked seasonal fluctuations in aldicarb concentrations occurred in several wells.

Notes: Abstract. An apparatus has been designed for collection of ground-water samples in locations of limited water flow when atmospheric contamination must be avoided. The system consists of a packer outfitted with valves, a flow cell, and probes for measurement of dissolved oxygen, pH, and Eh, and is designed for installation in a 3-inch (7.6-cm) diameter borehole. The oxygen probe, which is a commercially available electrochemical device, functions accurately without water flow or oxygen consumption. The borehole collector system has been used to characterize the ground water in the Climax granite stock at the Nevada Test Site of the U.S. Department of Energy.

Notes: Mount Emmons is located near Crested Butte, Colorado. It is the site of a proposed molybdenum mine that would extract ore from within the core of the 12,000-foot plus peak. AMAX Inc. is proposing to extract the ore body by utilizing a block caving technique that requires a thorough understanding of the hydrology of the mountain.This study was conducted to test the hypothesis that water quality data from various sources can be clustered and grouped into distinct populations that can be correlated with hydrogeologic features mapped on the mountain. Cluster analysis and canonical analysis are applied to mine water quality data, drillhole water quality data, spring-water quality data and surface-water quality data. Identified subpopulations indicate the presence or absence of mineralized sources in recharge areas, along flow paths or in discharge areas for the different water quality groups. The statistical analyses in combination with fault-vein mapping and debris slide mapping facilitate identification of preferential hydraulic connections between the surface of Mount Emmons and internal mineralized zones. The majority of the springs on Mount Emmons were shown to be derived from debris slides. These springs discharge water that meets drinking-water standards. The statistical analyses in combination with the hydrogeologic mapping indicate that these springs should not be affected significantly by mining. The analyses and hydrogeologic mapping also delineate those ground-water discharge areas that can be expected to be affected by mining. The delineation of the latter zones is essential to the mining plan; preventative and corrective measures can be implemented in the identified areas in order to assure that negative impacts of mining are avoided.

Notes: The presence of multiaquifer or multilayer wells changes the nature of the equations which must be solved in a three-dimensional ground-water flow simulation and, in effect, alters the stencil of computation. A method has been devised which takes this change into consideration by allowing simulation of the hydraulic effects of a multiaquifer well on the aquifer system. It also allows for calculation of the water level and individual aquifer discharges in such a well. The method is valid for the case of a single well located at the center of a square node block. Where more than one well per node is involved, the effects of the stencil alteration still must be considered, although difficulties arise in estimating and justifying the parameters to be utilized.

Notes: A numerical simulation and analytical study of a constant-rate pumping test, for a well situated at the centre of a disc of anomalous transmissivity and storage coefficient, have been used to aid in the interpretation of tests performed in a “patchy” aquifer in India. Equations describing the long-time behaviour of drawdown show that Jacob's method can be employed to estimate the regional transmissivity from drawdowns measured at any point in the aquifer or in the pumping well. However, these equations also show that an average storage coefficient should be calculated from drawdowns measured outside the aquifer discontinuity.The results of this study support the hypothesis that the average transmissivity of a heterogeneous aquifer can be calculated from rates of drawdown observed after long periods of pumping.

Notes: Microbial contamination of ground water results in numerous disease outbreaks each year. Tracing their movement in ground water is therefore essential. Bacteria, viruses, yeasts and spores have been used for this purpose and to trace underground movement of water in much the same manner as chemical tracers are used. Chemical tracers do not always reflect the movement of microorganisms in ground water. The use of certain bacteria and animal viruses is undesirable due to their pathogenic potential and difficulties in their differentiation from background, naturally-occurring organisms. Bacterial viruses appear to be the microorganisms most suited as a microbial tracer because of their size, ease of assay and lack of pathogenicity. Bacteriophages have been used to trace ground-water movement over distances of 1,600 meters and can be used under a variety of conditions.

Notes: Two programs are given for the CASIO FX-502 programmable calculator for direct computation of transmissivity and storativity from time-drawdown and distance-drawdown data. These aquifer parameters are calculated from Jacob's modification of the Theis equation by the least squares' method. The programs also calculate drawdowns at various times and distances using the computed transmissivity and storativity.

Notes: Meager Mountain is a recently-active andesite-dacite volcano situated 160 km NNW of Vancouver, British Columbia. The mountain is presently being jointly evaluated by the Geological Survey of Canada and the British Columbia Hydro and Power Authority as a potential geo-thermal resource. Limited existing and field-generated geological and hydrogeological data were employed to evaluate the ground-water flow regime at the study area. Mathematical modeling was carried out to determine the feasible range of ground-water-flow characteristics in the area. Field observations indicate that the water table is located at an intermediate elevation in the mountain system with the discharge area confined to the portion of the valley covered by unconsolidated deposits. Water balance calculations for the Lillooet River basin and baseflow determinations in the Meager Creek basin indicate that 14 to 17% of the total precipitation recharges the ground-water system. Various possible geological configurations were mathematically modeled with the water-table configuration and recharge rates restricted to the above ranges. The model results were used to predict the variations in the hydraulic conductivity in each geological formation. The results fell into a discrete range of values thought to be within an order of magnitude of the actual values.

Notes: Water quality data collected from monitoring wells in the Piceance Creek Basin oil shale area can be significantly influenced by well design and sampling techniques. Many of these influences can be attributed to hydrogeologic complexities, which can have notable variations on a fairly local scale. To adequately address these complexities, a site-specific characterization of the hydrogeology is necessary. This is particularly important for specifying well construction details of monitoring wells for a ground-water quality monitoring program.Data collected during the bailing of deep aquifer wells on Federal Prototype Oil Shale Lease Tract C-a indicates the need for consistent and representative sample collection depths. Appreciable changes in water quality can be induced by variations in sample collection depths. In addition, unrepresentative data can be obtained due to the incorrect selection of intervals to be sampled in the well. Care must be taken to sample consistently from the same depth and aquifer interval during each and every sampling effort.Studies such as these provide necessary background information for developing ground-water monitoring guidelines in the oil shale region. Sampling procedures must be consistent to assure representative data collection. In addition, wells should be designed and completed according to the local hydrogeology and the specific goals of the monitoring program.

Notes: Shoreline recession on the Great Lakes has caused millions of dollars worth of property damage in the lake bordering States and Canadian provinces. A variety of projects have been funded to study the erosion problem. The general conclusion of these studies is that wave action at the base of the bluff is the most important basic cause of bluff-top retreat. The purpose of this study was to investigate the role of various physical processes in causing bluff erosion. One part of the study was to ascertain the role of ground water in bluff stability. In this study, along a certain stretch of the Lake Michigan shoreline, 9 to 10 m (27 to 30 ft) per year of bluff-top recession that is not correlated to toe erosion was recorded. Heads were measured in 25 piezometers and a complex ground-water flow system was defined at this site. A glacial sand unit that is under artesian pressure was found 5 m (15 ft) above the toe of the bluff. Another “perched” system was observed in a fractured till unit at the top of the bluff. Water-table fluctuations have been recorded over a year and fluctuations of up to 13 m (39 ft) in the lower sand unit were measured. These fluctuations were found to have a significant influence on bluff stability. Pore pressures calculated from field measurements, along with the effective strength parameters of the soil units, were then used in the slope stability analysis to determine safety factors.Ground-water flow systems are found to be highly complex at the land-lake interface due to the inhomogeneities of the glacial materials that compose the bluffs. Furthermore, these complex ground-water flow systems influence the stability of the upper part of the bluffs. Because of the complexities, extrapolation of results to other stretches of the shoreline is difficult. However, methodologies and the awareness of how water-table fluctuations and multi-layered ground-water flow systems affect slope stability can be of help in other field situations.