ALBERT

Notes: An aquifer test and analyses of water samples, showed that the anomalous water quality of a municipal well was caused by leakage from a nearby abandoned well tapping another aquifer.

Notes: Electric-analog or digital-computer models are used to compute the effect of ground-water withdrawal or recharge on streamflow. The results can be generalized on a map showing lines of equal elapsed time. The lines indicate the time of recharging or discharging that is needed to affect the streamflow by a given fraction of the amount pumped or injected. The generalization is based on the similarity in shape of the relations between pumping time and stream depletion for (1) semi-infinite homogeneous aquifers drained by a straight, fully penetrating stream, and (2) complex heterogeneous aquifers. Response curves from a model reflect the combined effect of stream sinuosity, irregular impermeable boundaries, areal variation in aquifer properties, and imperfect hydraulic connection between the stream and aquifer. The elapsed-cime lines are identified by sdf (stream depletion factor) values. These values can be calculated from observations made on an electric-analog model and then may be used in a digital-computer program for determining the effects of ground-water pumping or recharge on streamflow.

Notes: Hydrologic systems in arid lands normally include a recharge area in mountains and a discharge area in lowlands often with an intermediate area of lateral flow between recharge and discharge areas. This system is often modified by local geologic, climatic, and physiographic factors. Most water-supply, contamination and disposal problems arise from a combination of features superimposed on this system by concentration of population and agricultural activity in the discharge areas. Also most of our data on the system comes from the lowlands and little data is available from the recharge areas.In the Great Basin two general categories of ground-water flow systems are recognized: (1) local flow systems where drainage areas are usually small, flow paths are relatively short, interbasin flow is uncommon, springs have large fluctuations in discharge, water temperature is low, and concentration of Na, K, Cl, and SO4 is low, and (2) regional flow systems, where drainage areas are large, flow paths long, interbasin flow common, springs have large discharge, and the water is characteristically of higher temperature and contains higher concentrations of K, Na, Cl, and SO4. Hydrologic approaches used, in addition to conventional methods, include hydrologic budget, water-potential, and water-chemistry studies. Although detailed delineation of most flow systems in Nevada has not been accomplished, integration of hydrologic, geologic, and chemical methods allow approximate portrayal of many systems, both local and regional.Adequate methods upon which to base planning for optimum development of water resources in desert basins are now available. A conceptual model of optimal ground-water reservoir development illustrates how to determine optimum use of storage and perennial yield provided the use to which the water is to be put and the time of withdrawal are known.

Notes: In 1965, a ground-water recharge facility was constructed and placed in operation to forestall an impending water shortage at Minot, North Dakota. The facility is unique in that the rate of recharge to a buried sand and gravel aquifer is augmented by perforating an overlying bed of clay using hydraulic connectors (gravel-filled bored holes) in conjunction with an open-pit excavation. The connectors were drilled by typical well-boring techniques and the open pit was excavated by common construction methods. The recharge technique made it possible to add about million gallons per day of water to underground storage with a total capital investment of about $200,000. The alternative originally proposed was a 50-mile long pipeline to Garrison Reservoir, at a 1959 estimated cost of $12,000,000. The recharge technique employed at Minot should have wide application in the ground-water industry in areas where natural recharge to permeable deposits is impeded by overlying beds of low permeability.

Notes: A totally new concept, called the Deep Tunnel Plan for Flood and Pollution Control, is being implemented by the Metropolitan Sanitary District of Chicago. The plan envisions temporary storage of combined sewer overflows in a system of tunnels excavated in solid rock, deep under the City. After the end of a storm, the stored water would be pumped to the surface where it would be treated to remove pollution before being discharged into the waterways.Early planning studies indicate that the most favorable location for the tunnels is the Galena-Platteville Dolomite which is the uppermost member of the Cambrian-Ordovician aquifer. The protection of this highly-developed aquifer from any possible contamination is therefore mandatory for the feasibility of the Deep Tunnel Plan.Preliminary investigations using an electric analog model, constructed on the basis of available data, indicate that aquifer protection can be provided by a system of recharge wells which would maintain flow into the tunnels at all times. Further detailed studies are in progress to verify and refine those preliminary conclusions. These studies include (a) detailed exploratory drilling; (b) controlled aquifer tests in selected zones; (c) pumping tests for specific capacity in the zone to be tunneled; (d) recharge injection tests; and (e) analog model analysis for future effects of the tunnels and recharge operations.

Notes: The interdisciplinary graduate program in hydrogeology at the University of Idaho is described. The curriculum is structured to permit the design of individual study programs which are in keeping with multiple use concepts. Flexibility sufficient to permit courses to be taken in several fields which support the students' major area of research is provided. This flexibility is maximized by the offering of two degree options. Discussion of a number of the research projects at the University illustrates several of the types of problems now being studied.

Notes: The University of Connecticut well field is located in a sand and gravel ice-contact stratified drift aquifer which fills the Fenton River valley to a depth of about 60 feet. The water that supplies these wells consists of captured ground-water underflow which would normally discharge into the Fenton River, and water induced directly into the aquifer from river flow by pumping. Measurements of streamflow made at three weirs installed in the Fenton River adjacent to two of these pumped wells show the influence of wells on streamflow. Approximately 34 percent of the water pumped from the wells was stolen from the river via induced streambed infiltration, although this figure varies in accordance with pumping. Water-level measurements in 30 observation wells installed in the aquifer around the pumped wells show that the cones of depression spread underneath the river, following coarse-grained partially buried eskers. The fact that the water table is detached from the river and is below the streambed near the pumped wells is explained by the low vertical permeability of the streambed in contrast to the horizontal permeability of the rest of the aquifer. The streambed is unable to recharge the aquifer with as much water as the aquifer can carry away. Time-drawdown pumping test plots show no effect of the river.

Notes: A resistance network analogue is used to study the early stages of a pumping test in an unconfined aquifer. The results are compared with an alternative analysis due to Boulton (1965) and a good agreement is obtained.Unlike the theoretical analysis the analogue technique is versatile and can easily be used to study pumping tests with nonidealized boundary conditions, e.g., partially penetrating wells can be simulated. Thus the analogue method of analysis could prove to be a more realistic method for studying pumping tests than standard analytical techniques.

Notes: Coarse granular deposits in preglacial river valleys are an important source of ground water on the Canadian prairies. Such an aquifer can commonly be modeled by an infinite-strip leaky-artesian aquifer. Test results can be analyzed, future drawdowns predicted, and safe yields estimated by applying the standard leaky-artesian formula in conjunction with image-well theory, making due allowance for well-loss factors.This paper develops basic formulas required for safe yield estimation for an array of n wells located on the axis of an infinite-strip leaky-artesian aquifer. In general, determination of safe yield for each well depends on the solution of n simultaneous linear or nonlinear equations. For certain symmetrical arrays, however, the number of equations to be solved is approximately halved. A linear equation will apply for any well if flow adjacent to the well bore always obeys the Darcy law for all pumping rates of interest. If all n equations are linear, they may be solved by the methods of matrix algebra; if not, a trial-and-error solution must be adopted.The method is illustrated by an application to a 6-mile stretch of a buried-valley aquifer near Edson, Alberta. The numerical coefficients in the system of equations are first derived and the equations then solved to obtain estimated 20-year safe yields for well arrays containing up to 38 equally spaced wells.

Notes: In 1966 more than 50 billion gallons of water was pumped daily from an estimated 10 to 15 million water wells in the United States. This was more than one-sixth of the national withdrawal of water. On the basis of past rates of increase, a much greater future use of ground water is suggested. Our annual investment in water wells is one-half to three-quarter billion dollars, not including pumps and plumbing. In 1964 approximately 436,000 new wells were drilled; however, less than 1 percent of these wells were logged by any geophysical means. The application of _ge_o.phy.sical well logging to ground-water hydrology is comparable to its use in petroleum exploration in the 1930's; however, we can take advantage of equipment and interpretation techniques developed in the oil industry that are available now for use in ground-water investigations.Although most petroleum well logging techniques may be utilized in hydrology; modifications in equipment and interpretation are necessary because of basic economic and environmental differences between petroleum and ground-water evaluation. If logging is to be widely applied to ground-water exploration and evaluation, the expense of equipment and services must be reduced. Fortunately, this can be accomplished, because most water wells are not as deep as oil wells and the temperatures and pressures are lower.The Water Resources Division of the U. S. Geological Survey is conducting research on the application of borehole geophysics to ground-water hydrology. The following logging devices are utilized in the evaluation of ground-water environments: spontaneous potential, resistivity, gamma, gamma-gamma, neutron, radioactive tracer, flowmeter, caliper, fluid resistivity, gradient and differential temperature, and sonic velocity. Lightweight logging sondes and control modules are operated by one man, either on a vehicle-mounted 6,000-foot logger or on a suitcase-mounted 500-foot logger. An inexpensive magnetic tape system has been developed and is used routinely for log recording and playback.If commercial well logging service is to be widely used in ground-water exploration and development, water well contractors, and State and municipal agencies must be educated on the advantages of obtaining more information from each hole drilled. It will be necessary also to demonstrate how well logging can provide much of this information. In addition, the well logging industry must adapt their equipment and services to the requirements of ground-water hydrology. The need for additional logging capability in this field exists at the present time and is expected to increase. Hopefully industry will be able to fill the gap.

Notes: Heavy development in certain areas of the United States and the growing shortage of additional, readily available water supplies therein have forced planners and hydrologists to resort progressively to more elaborate water-supply systems. Among the most elaborate and most expensive systems proposed to date are the various plans for. transferring water toward the south from northward flowing Arctic rivers. A considerable portion of this water would be utilized for the expansion of already heavily urbanized areas.Meanwhile, many of the densely populated areas experiencing water shortages are subjected to other, perhaps more complex problems which appear to be, at least in part, a product of their increasing size. Therefore, the expenditure of large sums to supply them with water for indefinite growth appears to merit scrutinous study.An alternative approach designed to minimize both water diversion costs and problems associated with over-populated areas is the stimulation of development in carefully selected regions well endowed with water and other natural resources. One such area and several of its attributes are discussed herein.

Notes: A gravity survey covering 250 square miles and including the Walnut Gulch watershed at Tombstone, Arizona has been conducted. The watershed is one of the experimental areas of the Southwest Watershed Research Center, Agricultural Research Service in Tucson, Arizona.The gravity survey method was selected as the geophysical method that would give a regional picture of the subsurface geology before making extensive surveys by the seismic. refraction method. Basically, the gravity survey method detects and measures variations in the earth's gravitational force. These variations are associated with changes in rock and alluvium density near the surface. Many geologic structures of interest in watershed ground-water hydrology cause disturbances in the normal density distribution which give rise to anomalies.The geology of the watershed is typical of Basin and Range province and contains deep basin fill deposits surrounded on the east, south, and southwest by igneous intrusives, volcanics, and sedimentary rocks. Concealed border faults may have a decided effect on the hydrology of the watershed.Four base stations were established and 360 gravity stations occupied by a Worden Educator* gravimeter loaned from the Geophysics Laboratory of the University of Arizona. Bench marks and large scale topographic maps served as control. Raw field data were reduced to the simple Bouguer anomaly values through the use of a computer program.The gravity survey reveals a 16-mgal. gravity low over the east-central portion of the watershed. This low is interpreted as indicating that about 3200 feet of low density alluvium underlies the area at this point. Gravity highs are associated with mountain ranges and igneous plugs where the more dense rocks occur.

Notes: Recent increased interest in subsurface disposal of industrial liquid wastes in Illinois has shown the need for both geohydrologic and engineering criteria and State regulatory policies for evaluating proposed installations, with the object of protecting other resources, chiefly potable ground water.Favorable geohydrologic conditions–specifically the presence of a variety of permeable formations that contain nonpotable water and are well confined from shallow to great depth–make waste disposal by wells feasible in much of the southern two-thirds of Illinois. Natural safeguards permit disposal wells to be planned with conventional engineering precautions and only a minimal program of preoperational testing.In much of the northern third of the State, the permeable rocks contain potable water to great depth, and there is moderate to high development of the ground-water resource because of urban and industrial concentration. Exhaustive testing, substantial proof of acceptable site conditions, and incorporation of optimum engineering safeguards are considered necessary before the State regulatory agency can authorize installation.

Notes: Comparative costs of ground water were needed for comprehensive planning of water resources development in the Susquehanna River basin in order to appraise the feasibility of alternative sources of water supply. Log-normal plots on logarithmic-probability paper that represented specific capacities adjusted to 180 days of pumping were used to estimate well yields and costs of obtaining the ground water from each of 65 potential aquifers. The 25, 50, and 75 percent probability of occurrence of the specific capacities of successful wells were used in the calculations. The estimated well yields at these probabilities of occurrence were obtained using hypothetical well designs and selected drawdowns. Ground-water costs for the estimated or design yields were calculated using amortized costs of well construction, electrical power costs, and maintenance costs, all obtained from standard sources.The calculated well yields and costs for the 25 to 75 percent probability interval range from 15 to 9,000 gpm (gallons per minute) and from $0.004 to $0.11 per thousand gallons of design yield. The yields and costs group according to aquifer rock type. The calculated costs decrease with increasing well yield and the available yield depends upon the aquifer rock type available. Representative costs per thousand gallons of design yield for selected yields from aquifers composed of different rock types analyzed are: 50 gpm −$0.060 for shale and interbedded sandstone and shale, and $0.050 for metamorphic rock; 100 gpm - $0.043 or shale and interbedded sandstone and shale, $0.037 for metamorphic rock, and $0.032 for carbonate rock; 500 gpm—$0.020 for sandstone, $0.015 for carbonate rock, and $0.012 for glacial sand and gravel; and 1,000 gpm —$0.009 for glacial sand and gravel. Differences in cost to obtain the same yield from different rock types are primarily due to differences in electrical power costs as determined by differences in pumping water levels.If used with caution, the generalized yield and cost estimates for aquifer rock types may have usefulness in estimating ground-water costs and yields in similar humid areas. They are primarily useful for planning and comparative purposes, but not for the actual design of engineering Projects.

Notes: Hazards to ground water may result from adding to water which may infiltrate the soil, or to the soil through which water percolates, wastes from man's life processes; his industrial and commercial activity; or his use of water, fertilizers and pesticides in agriculture. From experimental data it is evident that particulate matter, including bacteria and viruses, do not move far with percolating water in a soil system. The chemical products of biodegradation of organic wastes, however, with a few exceptions such as phosphates, move quite freely and hence reach ground water. Since they are no different than the compounds found in ground waters the effect of domestic use of water is generally to increase the concentration of salts normally present in such waters. From the vast spectrum of compounds produced by the chemical industry and used in industry and commerce comes hazards to ground-water quality such as metal ions, phenols, tar residues, brines, and exotic organics which may through accident, carelessness or waste-water discharge contaminate ground water. Mineralization with nutrients and soluble soil fractions, and possibly, pesticide residues are the hazards from agricultural use. Leaching from solid waste landfills is possible under poor long-term management and might involve chemicals, iron, and various earth minerals. It is concluded that the most serious hazard is the buildup of dissolved solids to levels inimical to beneficial use.

Notes: In this paper, basic design principles for disposal wells are set out and then exemplified by discussion of two recently constructed wells for disposal of very corrosive refinery waste. One well is designed for 700 gpm of waste containing 4200 ppm hydrogen sulfide. The other is designed for 50 gpm of waste containing 32 percent hydrochloric acid. Both wells are in the Gulf Coastal Plain and are completed in a deep, unconsolidated fine sand containing salt water. Screens fabricated from exotic metals were incorporated in the design. Unique combinations of materials were used for the casing.It is pointed out that oil field type completions are often used in disposal well construction, which usually results in low specific injection capacity, high operation and maintenance costs, and short useful life of the hydraulic structure.

Notes: A supply of good-quality water is our most critical natural resource, for our municipal growth and an increasingly healthy industrial base. The economic viability of our farms depends upon it. The locating and development of this resource is the province of the hydrogeologist.The hydrogeologist is more than just a ground-water geologist, for he deals with water in virtually every geologic situation, above-the water table as well as below it, and at the surface as well as underground.The hydrogeologist must of course possess the necessary background in the allied sciences and fluid mechanics, and should know something of the social science aspects of water decision-making. He must be able to work closely with the civil and sanitary engineers, and he must be able to make himself understood to planners.In performing his work he has a responsibility to society, and this is equated with a responsibility to his profession. As Martin Van Couvering has said, the respect that our profession deserves “cannot be bought or solicited; it has to be earned by the right kind of performance.”

Notes: The existence of high-density, nearly-structureless bedrock buried by relatively low-density sediments makes gravity prospecting a very informative technique for bedrock-topography studies of the northern Appalachian Plateaus. Locating bedrock exposures and using available well data reduces the area of the gravity search. Depths to bedrock from wells correlate excellently with depths from gravity anomalies. The minimum anomaly detected was 0·18 milligal, corresponding to a depth of approximately 40 feet.

Notes: A comparative study was undertaken on the decay rates of three bacterial types (S. typhimurium, E. coli and S. faecalis), an enterovirus (poliovirus type 1) and a bacterial phage (f2) in ground water maintained under laboratory conditions. Except for f2 phage, all the microorganisms tested were relatively stable in ground water. S. faecalis survived best among all the bacteria tested and its decay rate was similar to that of poliovirus type 1.Under field conditions, bacterial indicators were also found to be stable in the ground-water environment. The decay rate for fecal streptococci was lower than for fecal or total coliforms in the shallow wells.

Notes: A technique has been developed for the determination of the exchangeable cation population of calcareous sandy material with cation exchange capacities of less than 1 meq/100 g. The technique involves the addition of exchange salt in the dry state to samples of porous media using original pore water as the exchange salt solvent. In applying this technique to samples from below the water table, the amount of pore water available for reaction is reduced by centrifuging in the field to bring the moisture content close to field capacity values. By utilizing the minimum amount of pore water, interferences during the exchange process due to calcite precipitation or dissolution are minimized. The extent of calcite dissolution or precipitation that occurs can be appraised by measuring alkalinity or total carbon on the pore water before and after addition of the exchange salt. Three salts, NH4C1, CsCl and LiCl were tested for their suitability for this technique. CsCl was found to be preferable because of its low tendency to dissolve carbonate and the preference of Cs+ on exchange sites.Application of the method to a field site in southern Ontario yielded a value of 0.51 ± 0·09 meq/100 g over 15 samples for the cation exchange capacity of a near surface glaciofluvial sand deposit. It is believed that this technique could be applied with reasonable accuracy and reproducibility to materials with exchange capacities of as low as 0·1 meq/100 g.

Notes: The upconing of the salt-water interface in an unconfined coastal aquifer due to water withdrawal by an infiltration gallery is analyzed numerically based on the variational formulation of the problem. Sometimes in coastal areas, from the point of view of safe withdrawal of water on a long-term basis, the use of an infiltration gallery is found to be feasible in preventing severe upconing of the interface that would have resulted from heavy pumpage by a vertical well. The numerical procedure presented here is capable of delineating profiles of the free surface and interface along with the length of the outflow face and quantity of freshwater flow to the sea. Full consideration of the nonlinear boundary conditions on the free surface and interface is included for a steady flow towards a gallery in both isotropic and anisotropic aquifers. The extent of upconing of the interface under different operating conditions of the gallery for different aquifer geometries has been studied. A general understanding of the flow phenomenon in the vicinity of the gallery has been established. The results of the analysis can be used to plan a water withdrawal scheme without causing contamination by salt water.

Notes: The streambed-leakage factor ranged from 0.11 to 1.68 million gallons per day per acre per foot of head loss. Most values for the streambed infiltration rate and the streambed-leakage factor for six tests before 1970 were higher than for six tests in 1976–79, suggesting a change in streambed permeability in the intervening time.A well field to serve a government-owned uranium enrichment facility, consisting initially of 4 wells, later increased to 15 wells, was designed to yield up to 20 million gallons per day. The wells are on a line parallel to the river at distances from the stream ranging from 122 to 330 feet. Distance between wells ranges from 190 to 303 feet. Specific capacities of the wells, based on 24-hour acceptance tests, ranged from 63 to 147 gallons per minute per foot of drawdown and averaged 100 gallons per minute per foot of drawdown. By late Summer of 1976, pumpage from all 15 wells ranged from 12 to 15 million gallons per day. Drawdown was about as expected, based on design criteria developed from the aquifer tests, except that pumping levels were lower than expected in the Fall and Winter of 1976–77, resulting from low streamflow and low river temperature.

Notes: Vast deposits of oil shale are contained in the Piceance basin in northwestern Colorado. The basin may contain as much as 40 million acre-feet of stored water associated with these deposits, much of which may have to be drained for mining. Yet, most analyses of watersupply for oil-shale development have focused on surface water with only brief mention of ground water.This study used a synthetic streamflow model to investigate the effects of using conservative estimates of ground water on the required active storage capacity of a hypothetical reservoir on the White River. Results of the study indicate that use of ground water from mine drainage and/or auxiliary wells may have a significant impact on the size and timing of surface-water reservoirs. Thus, ground water may be an important source of supply, particularly during early development of an oil-shale industry. The study results strongly suggest that further investigations are needed on the physical availability of ground water as well as the institutional, legal and waterquality constraints on its use.

Notes: Egypt is presently involved in a comprehensive program of land reclamation. Surface water has already been exhausted in meeting the urgent needs of agricultural expansion. If irrigation efficiency were increased, large amounts of surface water would be saved. However, this entails complex social, technical and political problems outside the scope of this paper. Ground-water development has priority over increasing irrigation efficiency (which would take a longer time).This paper deals with identification of the intruded salt-water wedge in the huge artesian Delta aquifer. The case is unique because most of this aquifer is invaded by salt water, and the major portion of its annual ground-water recharge is derived from the direct seepage from the Nile River and the huge net of irrigation canals serving about 3 million acres (∼ 11,561 km2) of fertile land, as well as the infiltration of excess irrigation water. The annual overall ground-water recharge to the aquifer was estimated as 6·40 km3/yr as explained later.Methods of salt-water control and various techniques of water resources management are discussed in this paper. Because of the great variation in the depth of the aquifer, two unconventional methods for identifying the salt-water wedge are also presented.

Notes: . Programs are presented for the HP41C and TI59 programmable calculators for determining the ratio of horizontal to vertical hydraulic conductivity in anisotropic confined aquifers from pumping test data or for calculating drawdown given the aquifer parameters. The programs, based on Hantush's drawdown equations (1961), eliminate the need to perform triple interpolation in obtaining the drawdown correction factor given in tabular form by Weeks (1969). The programs are illustrated by example.

Notes: A numerical model of flow and transport in the vicinity of Price's Landfill and the Atlantic City public water-supply wells is used to estimate the extent of the existing contamination problem. Model parameters such as boundary conditions, pumping rates, permeability, and dispersivity are varied to demonstrate the sensitivity of the model to these quantities. A historical simulation of the past ten years of contamination is obtained and two schemes for remediation of the contamination problem are compared. In the light of this work, additional data requirements are revealed.

Notes: Ion-exchange high performance liquid chromatography coupled with ultraviolet absorption detection is shown to be a rapid and sensitive method for analysis of some common anions in water. Sensitivity of measurement is approximately 50 ppb for NO−2, NO−3, Br−, I−, and SCN− while Cl− has a detection limit in the one to ten ppm range. Chromatograms require 8 to 13 minutes to complete. Analyses are performed on either of two stationary phases (Whatman SAX 10 μm or Brownlee anion exchange) depending on the anions of interest in the analysis and their interferences.

Notes: Vertical electrical soundings using DC resistivity methods have been completed along over 60 miles of survey lines in southwest Florida. The resistivity soundings were obtained in order to outline major hydrogeologic features as part of a regional hydrogeologic investigation covering approximately 400 square miles. The two significant hydrogeologic features which can be effectively mapped on a regional scale by DC methods are the presence of shallow, high resistivity limestones associated with late Tertiary reef complexes, and the approximate depth to waters with TDS concentrations well above the potable water limits. The reef limestones commonly exhibit very high transmissivities and are potential sites for ground-water development. The approximate thickness of potable waters allows resource investigations to be limited to the most promising areas and a rough assessment of the total resource to be made for long-term planning. The interpretation and mapping of the resistivity section is accomplished through published resistivity inversion and computer graphics programs. This automated data processing produces resistivity maps and sections without requiring extensive geophysical training of the interpreter. The automatic interpretations compare well with more traditional master curve interpretation procedures, and have the same limitations with equivalence of solutions and geologic correlation, but are produced with considerably less effort.

Notes: With an Apple II microcomputer it is possible to rapidly generate and graphically compare theoretical time-drawdown curves with field data from pumping tests in confined aquifers. This technique has the advantage over standard curve-matching methods in that any solution can be tested over the complete range of field data.

Notes: Four formally equivalent response modes were used to elicit laypeople's beliefs regarding the lethality of various potential causes of death. Results showed that respondents had an articulated core of beliefs about lethality that yielded similar orderings of maladies by lethality regardless of the response mode used. Moreover, this subjective ordering was fairly similar to that revealed by public health statistics. However, the absolute estimates of lethality produced by the different response modes varied enormously. Depending upon the mode used, respondents were seen to greatly overestimate or greatly underestimate lethality. The implications of these discrepancies for public education and risk analysis are explored.

Notes: The differences between probabilistic risk assessment (PRA) and safety analysis (SA) are discussed, and it is shown that PRA is more suitable than SA for determining the acceptability of a technology. Since a PRA by the fault tree-event tree analysis method used for reactor safety studies does not seem to be practical for buried waste, an alternative approach is suggested using geochemical analogs. This method is illustrated for the cases of high-level and low-level radioactive waste and for chemical carcinogens released in coal burning.

Notes: Public opinion poll data have consistently shown that the proportion of respondents who are willing to have a nuclear power plant in their own community is smaller than the proportion who agree that more nuclear plants should be built in this country. Respondents’ judgments of the minimum safe distance from each of eight hazardous facilities confirmed that this finding results from perceived risk gradients that differ by facility (e.g., nuclear vs. natural gas power plants) and social group (e.g., chemical engineers vs. environmentalists) but are relatively stable over time. Ratings of the facilities on thirteen perceived risk dimensions were used to determine whether any of the dimensions could explain the distance data. Because the rank order of the facilities with respect to acceptable distance was very similar to the rank order on a number of the perceived risk dimensions, it is difficult to determine which of the latter is the critical determinant of acceptable distance if, indeed, there is only one. There were, however, a number of reversals of rank order that indicate that the respondents had a differentiated view of technological risk. Finally, data from this and other studies were interpreted as suggesting that perceived lack of any other form of personal control over risk exposure may be an important factor in stimulating public opposition to the siting of hazardous facilities.

Notes: This paper examines how LP/HC (low-probability/high-consequence) risk analysis is used in planning for locally unwanted land uses, or LULUs. LULUs are development projects that are predictably objectionable to many of their neighbors. Examples are nuclear power plants, hazardous waste facilities, refineries, and airports. The paper begins by elaborating the idea of LULUs, focussing on those whose planning typically requires or invokes some form of LP/HC risk analysis. It then discusses how land planning and planners actually use the LP/HC approach to deal with LULUs. It argues that in practice land-use planners and their associates employ a concept of risk different from that of economists, scientists, and engineers and more like that of political decision-makers and the public at large. It concludes with a political interpretation that offers some suggestions for productively reducing this divergence in the treatment of LULUs that pose LP/HC risks.

Notes: The rapid aging of the U.S. population, increases in the absolute prevalence of chronic diseases, and the associated rise in the proportion of the GNP expended on medical care all indicate the need for methods to accurately forecast future health care expenditures for specific chronic diseases. Additionally, if these methods are biomedically realistic, they can be used to evaluate the economic implications of specific prevention strategies designed to reduce chronic disease incidence, prevalence, and mortality. Projection strategies that are not biomedically realistic, such as models that assume that risks for demographic subgroups do not change over time (e.g., “static component” models), though possibly accurate over the short run, are not suitable for assessing the long term effects of specific proposed health policy interventions which are designed to alter risks.In this paper we present a strategy for forecasting health care costs which is based on a model that represents the natural history of a chronic disease in terms of a preclinical state, a clinical state, case fatality rates, cures, and the implications of exogenous medical factors. Using this model we project that the treatment costs associated with respiratory cancer in the white male population of the U.S. may undergo a two-thirds increase in real dollars over the period 1977 to 2000. About one-half of this increase is due to a demographic shift to an older population structure, with the remainder due to higher respiratory cancer incidence rates in younger cohorts. Alteration of certain parameters of the model to simulate various interventions suggests that about three-quarters of the cost of this disease could be eliminated, though realization of any significant part of this savings would require a lengthy phase-in period.

Notes: This methodology begins by quantifying the fragility of all key components and structures in the plant. By means of the logic encoded in the plant event trees and fault trees, the component fragilities are combined to form fragilities for the occurrence of plant damage states or release categories. Combining these, in turn, with the seismicity curves yields the frequencies of those states or releases. Uncertainty is explicitly included at each step of the process.

Notes: A classical decision problem is considered where a decision maker is to choose one of a number of actions each offering different consequences. The outcome from a choice of action is uncertain because it depends on the existing state of Nature. Also, the outcome, once an action and state of Nature are specified, may be a vector or a random vector. The decision maker employs both Bayesian methods and fuzzy set techniques to handle the uncertainties. The decision maker is also allowed to use multiple, possibly conflicting, goals in order to determine his best strategy. The Bayesian method produces a set of undominated strategies to choose from, whereas the fuzzy set technique usually produces a unique optimal strategy.

Notes: Scientists have long used conventional toxicological methods to establish “safe levels of exposure” for chemicals presumed to have threshold health effects or doses below which significant effects are unlikely to occur. These same methods cannot be used to establish safe levels of exposure for non-threshold pollutants, such as carcinogens. Therefore, Federal regulatory agencies in the United States are using risk assessment methods to provide information for public health policy decisions concerning increases in risk associated with increases in exposure to carcinogenic and other non-threshold pollutants. Acceptable exposure/risk levels are decided by policymakers who consider descriptions and estimates of risks together with social and economic benefits from the uses of the chemical. This paper focuses on the development of quantitative risk assessment approaches by Federal regulatory agencies in the United States, and identifies the mathematical models currently being used for risk extrapolation, including their inherent uncertainties. The uncertainties and limitations of these methods have led some scientists to question the utility of quantitative risk extrapolation. The experience of the U.S. Environmental Protection Agency (EPA), as summarized in this paper, can provide a realistic basis for evaluating the pros and cons. Finally, shortcomings in current risk assessment methods and their use in policy decisions are explored, and areas for possible improvement, given current scientific knowledge, are identified.

Notes: Risk acceptance criteria in the form of limit lines are investigated in the context of prospect theory. This theory departs from utility theory in several respects, an important one being the use of weights other than probabilities in the evaluation of the expected impact of uncertain outcomes. Hypothetical functions reflecting certain attitudes toward consequences and rare events are developed and combined to produce several limit lines.

Notes: In this paper, we argue that risk in a new situation can be calculated by comparison with the most closely analogous previous situation that we can find. In many cases, such as automobile accidents, we argue that this year is analogous to preceding years. With toxic chemicals the analogy is less direct—we compare with other toxic chemicals or with chemicals shown to be toxic in other species. Because the unreliability or uncertainty of the analogy can be high, it is necessary to use less sensitive, but more reliable, methods of estimating risk to prevent continued use of a hazardous material, and subsequent tragedy if the hazard should turn out to be unexpectedly large. This suggests more robust techniques to reduce the regret, or societal cost of being wrong, because increased sensitivity is sometimes attained at the expense of sampling error.

Notes: Analysis of energy-system impacts requires quantifications of short- and long-term local, regional, and global modifications. This paper describes and illustrates an approach for assessing long-term health risks due to dispersion of naturally occurring radionuclide series and chemical toxins by normal and altered landscape-chemical cycles. Health hazards are expressed as dose factors which convert environmental concentrations into a corresponding dose field (organ doses in rad for radionuclides; daily intake for toxic elements). The dose field is translated into a population health risk. The external environment is modelled by considering the manner in which elements are distributed and mobilized within the earth system. The landscape prism is presented as a tool for visualizing and mapping toxic material cycles near the crustal surface. An approach is provided for dividing the landscape into a set of compartments consistent with patterns of element circulation observed in the global environment. We investigate the response of regional landscapes to increases of 238U, 226Ra, arsenic and lead in soil and groundwater. It is found that each decay series or element imposes a hazard by its behavior in the total environment that cannot be quantified by a simple measure of toxicity.

Notes: Many risks have the property that large numbers of people are exposed and have little or no individual control over the risks they face. Dams, nuclear power plants, and recombinant DNA research have proven controversial not simply because there is vast uncertainty about the true level of risk associated with each, but because a fundamental issue is that in each case social risks can be lessened by spending more on safety: dams can be designed to withstand larger earthquakes, nuclear plants can have additional safety equipment, and DNA research could be done in yet more carefully isolated laboratories. Since each person will have preferences regarding the proper trade-off between increased cost and increased safety, there is little possibility of consensus. More importantly, we show that a voting process for expressing individual preferences can be manipulated and is seriously flawed in the sense that it does not lead to an “efficient” outcome. In addition, we show that virtually all people are unhappy with the safety decision, in the sense that each would prefer either a safer or a cheaper outcome. Thus, making safety decisions that affect a large group of people who will not be able to control the outcome is even more difficult than has been appreciated. We suggest some ways of handling some of the difficulties.

Notes: An estimation of the human lung cancer “unit risk” from diesel engine particulate emissions has been made using a comparative potency approach. This approach involves evaluating the tumorigenic and mutagenic potencies of the particulates from four diesel and one gasoline engine in relation to other combustion and pyrolysis products (coke oven, roofing tar, and cigarette smoke) that cause lung cancer in humans. The unit cancer risk is predicated on the linear nonthreshold extrapolation model and is the individual lifetime excess lung cancer risk from continuous exposure to 1 μg carcinogen per m3 inhaled air. The human lung cancer unit risks obtained from the epidemiologic data for coke oven workers, roofing tar applicators, and cigarette smokers were, respectively, 9.3 × 10−4, 3.6 × 10−4, and 2.2 × 10−6 per μg particulate organics per m3 air. The comparative potencies of these three materials and the diesel and gasoline engine exhaust particulates (as organic extracts) were evaluated by in vivo tumorigenicity bioassays involving skin initiation and skin carcinogenicity in SENCAR mice and by the in vitro bioassays that proved suitable for this analysis: Ames Salmonella microsome bioassay, L5178Y mouse lymphoma cell mutagenesis bioassay, and sister chromatid exchange bioassay in Chinese hamster ovary cells. The relative potencies of the coke oven, roofing tar, and cigarette smoke emissions, as determined by the mouse skin initiation assay, were within a factor of 2 of those determined using the epidemiologic data. The relative potencies, from the in vitro bioassays as compared to the human data, were similar for coke oven and roofing tar, but for the cigarette smoke condensate the in vitro tests predicted a higher relative potency. The mouse skin initiation bioassay was used to determine the unit lung cancer risk for the most potent of the diesel emissions. Based on comparisons with coke oven, roofing tar, and cigarette smoke, the unit cancer risk averaged 4.4 × 10−4. The unit lung cancer risks for the other, less potent motor-vehicle emissions were determined from their comparative potencies relative to the most potent diesel using three in vitro bioassays. There was a high correlation between the in vitro and in vivo bioassays in their responses to the engine exhaust particulate extracts. The unit lung cancer risk per μg particulates per m3 for the automotive diesel and gasoline exhaust particulates ranged from 0.20 × 10−4 to 0.60 × 10−4; that for the heavy-duty diesel engine was 0.02 × 10−4. These unit risks provide the basis for a future assessment of human lung cancer risks when combined with human population exposure to automotive emissions.

Notes: In this paper we extend the work reported in prior studies. The conclusion drawn from the aggregate of those studies was that the limitation on liability imposed by the Price–Anderson Act for a catastrophic accident at a nuclear power plant ($560 million) is comparable to de facto limitations on recovery following catastrophic events in many other industries. The analysis in those reports was at a high level of abstraction, comparing almost exclusively the potential loss from high consequence accidents with the current assets of major firms in relevant industries. We found that potential loss exceeded assets.

Notes: The U.S. Office of Science and Technology Policy describes toxic substance regulation as composed of two stages. Stage I (facts) uses empirical data and scientific judgment to characterize human exposure and risk. Stage II (values) uses social and political judgment to decide regulatory action based on significance of the risk, benefits of the agent, and costs of its control. This paper argues that such a view represents an unrealistic and unattainable goal. We present examples showing how values enter virtually every part of risk analysis, and we review work on the vagaries in human judgment concerning both facts and values. These issues indicate that U.S. regulatory policy needs reconsideration.

Notes: In this paper we propose a framework for conducting a decision analysis for a societal problem such as earthquake safety. The application deals with the formulation and evaluation of alternative policies for the seismic safety problem faced by the city of Los Angeles with regard to its old masonry buildings. A social decision analysis compares the costs and benefits of the alternative policies from the viewpoints of the impacted constituents. The emphasis is on identifying acceptable policy that considers the interests of the impacted constituents and provides incentives for their cooperation. Alternatives ranging from strict regulation to free market are examined. In order to evaluate the trade-offs between additional cost and savings in lives, a direct willingness-to-pay and an economic approach, based on property value differential, are used. Recommendations range from strict regulation for the residential and critical buildings (schools, hospitals, fire stations, etc.) to simply informing the occupants (in the case of commercial and industrial buildings) of the risks involved.

Notes: Measures to tighten homes to conserve energy, as are being encouraged and subsidized by federal and state governments, may reduce air infiltration by 20% or more. Standard prudent risk-assessment methodologies predict that, due to increased levels of indoor radon caused by this reduction in ventilation, the added lifetime lung cancer risk to members of the public is of order 200/million people exposed. In situations where the radon source term is unusually high, or extreme reductions in ventilation are made, the added risk can be more than an order of magnitude greater. While these imputed risks are far outside the range that is normally tolerated, no systematic efforts are in progress to mitigate or limit the risk in any way. Furthermore, efforts to determine better the variations in radon source term and the health effects of indoor radon are being deemphasized. The technical background is presented in some detail, and implications with regard to management of risks to the public are discussed.

Notes: Book Reviewed in this article:Risk Analysis of Six Potentially Hazardous Industrial Objects in the Rijnmond Area, A Pilot Study

Notes: Water well drillers gather information essential to recovery tests as part of normal procedure. Added effort could yield additional valuable information. More care in measurement of water levels both before and after a period of pumping can be used with ground-water formulae to determine approximate well efficiency.A relationship exists between the ability of an aquifer to perform (transmissibility) and the specific capacity of a well. By means of pumping tests, both transmissibility and specific capacity may be measured. The theoretical specific capacity can be obtained based on the measured transmissibility. Well efficiency may be estimated from a comparison between measured specific capacity and theoretical specific capacity.Tests of wells owned by the City of Houston, Texas, were selected for analysis. Test results were compared with curves showing theoretical relationships. From the comparison, wells in the Houston area are not completely developed. It may not be economical to develop a well to 100 percent efficiency, but theoretical relationships should be used in well development.

Notes: The ages and origins of saline ground waters in coastal aquifers can be important indicators of local aquifer flow characteristics. Unfortunately, attempts to classify such waters using established trilinear diagram techniques are frequently inconclusive due largely to the dominance of sodium and chloride ions. In a study of saline ground waters from the Chalk limestone of eastern central England, an alternative, less conventional, dilution diagram procedure is employed which reveals previously unrecognized differences in local major ion chemical character. These differences are interpreted in terms of the origins of the saline ground waters and their histories of mixing. Significantly, the interpretations reinforce and, in some cases, refine earlier interpretations based on notably less extensive minor ion and environmental isotope data. It is concluded that the saline ground waters are associated with at least three periods of saline intrusion during the past 120,000 years.

Notes: A programmable calculator program is given along with examples for a general impulse response function for calculating step and rectangular pulse response for stream-aquifer interaction, pumping in leaky and nonleaky artesian aquifers, and two-dimensional dispersion.

Notes: The Pearl Harbor aquifer, an important ground-water resource for southern Oahu, Hawaii, contains an enormous fresh-water lens, up to 300 m (1,000 ft) thick, floating above saline water. The upper boundary of the fresh-water lens is confined near the coast and phreatic inland, whereas its lower boundary is not confined. A finite-difference flow model was used to simulate the Pearl Harbor aquifer system. The location of the fresh-water/salt-water interface, which constitutes the lower boundary of the flow system model, was estimated by Hubbert's formula. Known geohydrologic boundaries and aquifer parameters were also simulated. First, formation of the lens by filling the aquifer with fresh water from natural recharge was simulated to reconstruct the initial conditions before exploitation of the lens and to partially calibrate the model against the hydraulic-head distribution in 1879. The model then was calibrated fully by simulating the lens’reponse to actual historical pumping patterns covering a time span of 100 years (1880 to 1980). Simulated heads compared favorably with the observed heads over time and space. The calibrated flow model may serve as a useful tool in the management of the Pearl Harbor aquifer.

Notes: Most underground coal mines in Illinois are relatively dry despite their location in saturated rock lying hundreds of meters below the water table. This is probably due to the low permeabilities of the rock units associated with the coal seams. Little is known about how mines affect the groundwater system, so it is difficult to predict where a mine is likely to encounter an influx of ground water.To obtain information on the hydrogeological character of the roof rocks, an array of piezometers was installed in roof-bolt holes at two locations within an underground coal mine in central Illinois. Pressure vs. time measurements were obtained from piezometer arrays located in areas of the mine ranging from dry to wet conditions. Data collected from the piezometers indicate that water drainage from a saturated sandstone above the coal is largely controlled by local structural and stratigraphic features, and these features determine the distribution of wet and dry areas in the mine. Hydraulic conductivities of the sandstone were determined in the laboratory and in situ from drainage profiles and from tests of instantaneous head changes. Results of these tests indicated that dewatering in front of mining would not be successful in this mine.

Notes: A hydrogeologic investigation was conducted to determine the source of recharge to the Littlefield Springs, a series of carbonate springs occurring along a 10 km (6 mile) reach of the Virgin River in northwestern Arizona. The most probable sources of recharge to the springs were determined to be influent Virgin River water and precipitation within the springs hydrologic basin. These recharge sources could account for the total discharge of the springs. The Littlefield Springs have essentially constant discharge 1.84 cms (65 cfs), and quality 2940 mg/L TDS. Tritium analyses of the spring and river water indicate that there are at least two different sources of recharge to the Littlefield Springs–one a minimum of 22 years old and the other younger than 22 years old. Analysis of the influent Virgin River upstream from the springs indicates a 1·42 cms (50 cfs) loss at 2130 mg/L TDS and the same ionic ratio of dissolved constituents as the springs. The travel time of this recharge source is interpreted to be a minimum of 22 years. Local recharge to the springs has been estimated to be 0·31 cms (11 cfs). The presence of local recharge is indicated by pulse train gaging of the springs, and by water quality at a well upstream of the springs and at the first upstream occurrence of the springs. The travel time of this recharge source is interpreted to be less than 22 years.

Notes: The cation composition of water in the Aquia aquifer of southern Maryland changes systematically in the direction of ground-water flow. In the upgradient parts of the aquifer, calcium is the dominant cation in solution. Between 10 and 20 miles downgradient, calcium and magnesium are dominant. Between 20 and 35 miles downgradient, magnesium and potassium are dominant, and, beyond 40 miles downgradient, sodium is the most abundant cation in solution. The exchangeable cation composition of glauconite in the Aquia aquifer changes systematically in the direction of flow in a manner similar to the changes in water chemistry. These observations are interpreted as evidence that cation exchange reactions are processes that simultaneously alter water composition and glauconite composition along the flowpath.Exchange parameters K’and n for glauconite in the Aquia aquifer were determined for the reactions: 〈displayedItem type="mathematics" xml:id="mu1" numbered="no"〉〈mediaResource alt="image" href="urn:x-wiley:0017467X:GWAT343:GWAT_343_mu1"/〉〈displayedItem type="mathematics" xml:id="mu2" numbered="no"〉〈mediaResource alt="image" href="urn:x-wiley:0017467X:GWAT343:GWAT_343_mu2"/〉〈displayedItem type="mathematics" xml:id="mu3" numbered="no"〉〈mediaResource alt="image" href="urn:x-wiley:0017467X:GWAT343:GWAT_343_mu3"/〉 The exchange parameters for each reaction were tested by an indirect method. Molar ratios of exchangeable cations or glauconite were calculated from water chemistry data using the derived k’and n values. In each case, the trend of calculated molar ratios compared favorably with measured molar ratios. The calculated exchange parameters demonstrate that the exchange process is not linear for the Ca2+ -Na+ and Mg2+ -Na+ ion pairs.The sum of exchangeable cations on glauconite samples is significantly lower in the outcrop area than downgradient. Corresponding to this, the concentration of dissolved silica and dissolved oxygen in Aquia water is high near the outcrop area and decreases downgradient. This pattern suggests that incongruent dissolution of glauconite is an additional process that modifies glauconite composition near the outcrop area but is less important downgradient.

Notes: One of the primary problems in field investigations of ground-water pollution is locating the contaminant plume. Drilling of sampling holes on a hit-or-miss basis is both time-consuming and expensive. Under many subsurface conditions, surface electrical resistivity profiling can quickly and cheaply locate the general position of the plume and identify areas most feasible for sampling and monitoring. Many contaminants contain an ionic concentration considerably higher than the background level of native ground water. When such a contaminant is introduced into an aquifer, the electrical resistivity of the saturated soil is reduced. Surface electrical resistivity profiling across a suspected area can identify this reduced resistivity zone as an anomaly. The sensitivity of the method depends on relative uniformity of geology and topography as well as minimal extraneous electrical interferences. It is also essential that the “A” spacing used in the profiling procedure be carefully selected. If the resistivity contrast between contaminated and uncontaminated ground water is high, detection of at least the central part of the plume is likely within expected geologic variation. The method has been successfully used in the location of plumes from contaminants including brine, uranium reprocessing liquid wastes and landfill leachate in glacial deposits of New England.

Notes: The Piper (1953) trilinear diagram has been widely used to graphically represent the dissolved constituents of natural waters and to test for apparent mixtures of waters from different sources. Because of the time required to plot points and calculate the proportional values of mixing, this treatment of data was often quite tedious, particularly in studies involving large numbers of chemical analyses. The PIPER program was written in BASIC to be run on a Hewlett-Packard desktop computer with an X-Y plotter. Data input is in ppm units. The program plots points in all three fields of the trilinear diagram, draws at each point within the central diamond field a circle with a radius correspondent to the concentrations expressed in meq/1, checks for points that fall on a straight line (or within a predetermined tolerance of a straight line) representing postulated mixtures with two end members, and/or within a triangle representing mixtures of three end members. Finally, the program does a numerical analysis of the mixing ratios of the constituents for postulated mixing systems according to the methodology as presented by Piper (1953).

Notes: An induction-tuned device was designed and tested under a variety of well casing conditions. It can detect casing lengths to within 0.4 to 2.0 inches for casing ranging from 2 to 14 or more inches in diameter which are made of either magnetic or nonmagnetic metals. A casing separation as small as one inch is detectable for 12-inch diameter casing and a four inch or more separation is detectable for 4-inch I.D. casing. These values indicate the range in sensitivity expectable when determining casing separations.Dial readings in microamps are indicated as the ptobe is raised or lowered within a well bore. Readings vary depending whether the probe is centrally located or located to one side. The maximum and minimum dial reading is established for a given casing diameter at the start of a survey. A consistent change in dial reading from previous valves indicate a casing diameter change.The sensing element is a coil whose inductance is changed by varying its proximity to any metallic conductor. A coil and capacitor in parallel make a tuned circuit resonant at 3 K.C. The device includes a transistor in a phase shift oscillator, and a second transistor which acts as a current amplifier, a 0–100 μa d. c. meter driven through a bridge rectifier, capacitors, and other elements. Twelve to 14 volts at 4 to 6 milliamperes or less than 0.1 watt is sufficient to power the device.A maximum meter reading is obtained by adjusting an oscillator to the resonant frequency of the probe. Lowering the probe into a well casing detunes the probe, changing its impedance and the meter reading.All electrical elements are standard except the probe and all materials can be purchased for about $40.00 exclusive of the reel and cable assembly.

Notes: The electrical resistivity method has been a valuable tool used in the discovery of ground-water recharge facilities with percolation capacities in excess of 100,000 acrefeer per year. The procedures used in doing the field work and the methods of plotting the data are described using a typical area where studies were made. Correlations of soil types, recharge rates, and resistivity data for Santa Clara -County are included. Ground-water level data from observation wells are used to measure the regional and long-term effects of the ground-water recharge program.

Notes: Buried valleys are classified into two main types — those valleys completely buried by glacial drift, without present streams along their courses (Type I), and those partly buried or partly exhumed, usually with present streams along their courses (Type II). If a stream is flowing mainly in a Type II valley, the bottom of which is deeply buried by drift, local areas where the stream is cutting bedrock are postglacial channels of derangement. Postglacial channels of derangement, which often can be recognized on a topographic map, reveal that a buried valley (often Type I) exists nearby.