ALBERT

Notes: Few studies have been performed on the occurrence of enterovirus contamination of ground water. In this study, 99 ground-water samples were examined for the presence of enteroviruses, total bacteria, fecal coliforms, and fecal streptococci by standard methods. Enteroviruses were isolated from 20% of the samples. Viruses were isolated from 12 samples which contained no detectable fecal organisms per 100 ml. No statistical correlation between presence of virus and bacteriological indicators could be determined. The widespread failure of current bacteriological standards to indicate the presence of potentially pathogenic enteroviruses in ground water is an area of concern that requires more study.

Notes: Flow to wells in leaky artesian aquifers is intimately related to changes in aquitard storage, well storage capacity, and degree of well penetration. The manner and extent to which these and other factors affect water levels may be evaluated with aquifer test data. Families of type curves describe time-drawdown in the aquifer and aquitard under complex aquifer and well penetration conditions. Analysis of leaky artesian aquifer test data is possible with the array of equations derived largely in the 1950's through 1970's. Erroneous data analysis will result unless complicating factors are fully recognized and taken into account. A review of leaky artesian aquifer test evaluation methods is presented in this paper together with the field application of selected methods to foster greater use of current theories.

Notes: Illinois aquifers furnish approximately 233 mgd (10.2 m3/s) of water to 677 public-water supplies outside the six-county area of northeastern Illinois. Ground water is usually obtained from sand-and-gravel deposits in the glacial drift or from limestone or sandstone formations in the underlying bedrock. The most favorable ground-water conditions are found in the northern third and the southern tip of the State, while, elsewhere, major aquifers are sand-and-gravel deposits of the Mississippi, Illinois, buried Mahomet, Wabash, Ohio, Kaskaskia, and Embarrass valleys.A brief review was made of data and information in the State Water Survey files for each public ground-water supply, and an assessment was given as adequate, marginal, or deficient, in terms of present demands. Twenty-four supplies were studied in greater detail, including calculations of aquifer sustained yields. The study indicated that 39 supplies were marginal and four were judged deficient in meeting current demands. The majority of the marginal and deficient supplies are located in the central third of the State; but so are most of the supplies (outside of north-eastern Illinois).The study represents the first of a three-part plan to: (1) define problem areas and determine priorities for studies in greater detail, (2) conduct regional studies, including test drilling, in problem areas to determine how great the water resource is, and (3) determine the water resource alternatives available to public ground-water supplies that are found to be inadequate.

Notes: An industrial waste liquid containing organonitrile compounds and nitrate ion has been injected into the lower limestone of the Floridan aquifer near Pensacola, Florida since June 1975. Chemical analyses of water from monitor wells and backflow from the injection well indicate that organic carbon compounds are converted to CO2 and nitrate is converted to N2. These transformations are caused by bacteria immediately after injection, and are virtually completed within 100 m of the injection well. The zone near the injection well behaves like an anaerobic filter with nitrate respiring bacteria dominating the microbial flora in this zone.Sodium thiocyanate contained in the waste is unaltered during passage through the injection zone and is used to detect the degree of mixing of injected waste liquid with native water at a monitor well 312 m (712 ft) from the injection well. The dispersivity of the injection zone was calculated to be 10 m (33 ft). Analyses of samples from the monitor well indicate 80 percent reduction in chemical oxygen demand and virtually complete loss of organonitriles and nitrate from the waste liquid during passage from the injection well to the monitor well. Bacterial densities were much lower at the monitor well than in backflow from the injection well.

Notes: Abstract. This investigation was to determine whether data on irrigation-well registration forms as reported by well drillers can be used in hydrologic studies. Transmissivity maps were prepared for Hamilton County, Nebraska using only specific capacity values computed from yield and drawdown data, as reported on irrigation well-registration forms. On one map each control point was the mean of the transmissivity values calculated for all wells in a section. On a second map each control point was the mean of the means for four contiguous sections sharing a common corner. The second map was similar to that of a previously prepared map based on control point values computed from specific capacities of selected wells, test hole logs, and geologic interpretations. These results suggest that reported registration data for a given area have a normal population distribution. In situations where individual data are unverified the data base can be treated as samples of a population where the mean of the means of several samples for adjacent areas is representative of actual field conditions.

Notes: A new method of testing anisotropic, inhomogeneous multiple aquifer systems developed by the author makes use of small diameter bore construction techniques and enables simultaneous testing of superposed aquifers and aquitards (aquicludes).Because of the low cost of the method the hydraulic properties of the multiple aquifer system can be determined at many sites distributed throughout the area of interest, enabling simulation of the local and regional ground-water flow conditions and other hydrological characteristics of the system.Since its development in 1964 the technique improved and was employed in ground-water investigations. Data and results from the inhomogeneous, anisotropic multiple aquifer system west of Melbourne are given.

Notes: Chemical and isotopic analyses were made of water from wells in and downgradient from a landfill to determine chemical and isotopic effects of generation and migration of leachate on ground water. The distribution and wide concentration range of oxygen and methane permit the delineation of an anaerobic zone, a regional oxygenated zone and an intermediate zone. The ratio of reduced nitrogen to nitrate indicates location of reducing fronts as the leachate migrates. The pH of the native ground water is low (≥5.0) primarily because of the low pH of rainfall and the lack of calcareous or other soluble minerals in the aquifer material. The pH is higher (∼6.6) in the leachate because of generation of carbon dioxide, ammonia, and methane. The native ground water has a low TDS (80 mg/l) while the leachate has an average TDS of 2800 mg/l and is primarily a NaHCO3 type water. Sulfate concentrations are extremely low and H2S was not detected.We suggest that a major source of cations may be their exchange from the clays by the ammonium generated in the leachate. High concentrations of Fe and Mn are attributed to a source in the refuse but more important to reduction of oxide cements and coatings resulting from degradation of organic matter. The main source of bicarbonate is from organic degradation with minimal CO2 from the soil zone. At one landfill site 52% of the total alkalinity is attributed to organic compounds, mainly organic acid anions. The δ13C of bicarbonate in the leachate is exceedingly heavy (+18.400/00) which results from fractionation during the formation of methane. The 10 per mil deuterium enrichment of water may be due to decomposition of deuterium-enriched compounds and bacterial processes that preferentially consume the lighter hydrogen isotope.

Notes: Rapid fissure flow has been recognised as an important factor in understanding the hydraulic behaviour of the Lincolnshire Limestone aquifer of eastern England. A study of the hydrogeology of a Lincolnshire Limestone spring-fed catchment enables three zones of discharge to be defined, based on their relative elevation along the valley floor. Comparison of the discharge characteristics of each zone reveals the existence of rapid ground-water flow associated with a discrete fissure system. Comparison of spring discharges and ground-water storage during a period of “high,”“low” and “typical” recharge enables a conceptual flow model of the aquifer to be constructed. A two-layered model is proposed, in which the secondary zone (upper unit) is characterised by higher transmissivity and lower storativity than the primary zone (lower unit). In addition, there is evidence of a rapid increase in transmissivity with water-table elevation in the secondary zone. The areal distribution of the secondary zone is associated with a net work dry valleys. The spatial distribution of the two zones is explained by geological structure, lithological variations and the post-glacial history of the area. A two-layered model is developed with these concepts in mind in order to simulate the spring discharges. Once proven, the model can be integreated with the regional hydrogeology and incorporated into existing digital models of the aquifer.

Notes: Abstract. An evaluation was made of the usefulness of the gamma-ray logger in delineating glacial-drift and bedrock stratigraphy in southwestern Ohio. The logger was useful in delineating gross stratigraphic units in a glacial outwash aquifer. The gamma log also provided a clearer indication of the clay content of sand and gravel units than did the driller's log.On the uplands, away from the valleys filled with glacial outwash, the logger could not be used to locate the thin, poorly-sorted, interstadial sand and gravel deposits between thicker till sheets. It could, however, be used to distinguish formational contacts in the upper Cincinnatian Series.

Notes: Injection of waste liquids into Florida's subsurface is physically feasible in many places but should be accompanied by monitoring of the waste-receiving aquifer system in addition to the injection facility. Monitoring of the interaction of factors including hydrogeologic conditions, well construction, waste volumes and characteristics, and potable-water sources is desirable to assure that fresh-water resources are not being adversely affected. An effective aquifer-system monitoring program includes on-site wells located close to an injection well and open to the next-higher permeable stratum, satellite wells located hundreds to several thousands of feet from an injection well and open to the receiving aquifer, and regional wells located miles from individual injection wells and open to the receiving aquifer. An extensive aquifer-system monitoring program associated with two waste-injection facilities near Pensacola, Florida, has provided data which have aided hydrologists to understand the aquifer system's response to the injection and, accordingly, to evaluate the potential for affecting the area's fresh-water resources.

Notes: Overexploitation of ground water in Krishni-Hindon interstream region (Lat. 29°05′N-29°29′N and Long. 77°19′E-77°32′E) in Uttar Pradesh, India, prompted us to carry out aquifer modeling studies. The area lies in Gangetic alluvial plain. The interconnections in the phreatic aquifer and the lower semiconfined aquifer led to the assumption of a single-story aquifer for which an R-C analog model was constructed.The input-output quantities in the model have been simulated using current/voltage generators and current sinks which are appropriately programmed in time-domain with the help of wave-form synthesizers for a realistic representation of the field system.The model study shows that the aquifer can sustain the present output rate of 200 mcm/year without much damage to the ground-water regime. In another scheme, an annual increase of 5% in exploitation rate, shows deleterious effects on the aquifer. Decreased rainfall/ droughts would worsen the situation.The influence of hydraulic connectivity between the aquifer and the Krishni-Hindon river system is quite significant. If the present exploitation rate were to continue for 20 years, the annual inflow to the aquifer from rivers is estimated to increase by about 36.0 mem.More hydrogeological data is required for further validation and refinement of the model.

Notes: Generally, the 208 planning approach is deficient in a number of ways. Its origin lies in Public Law 92-500, which focuses on protection of surface water and special uses of water for fish, wildlife, and recreation. Little ground water is used for these purposes. Nonpoint sources have not been defined in terms that have hydrogeologic significance. Local and State regulatory agencies have often been unsuccessful in controlling ground-water pollution, yet the 208 approach tends to disregard the reasons for this situation. The reasons for ground-water pollution in an area must be understood before meaningful control measures can be enacted. These include both technical and institutional problems.Planners are placed in the forefront of many 208 programs at the local level and often their backgrounds are inadequate in ground water. There is a great lack of ground-water professionals in regulatory agencies involved, particularly in the Southwest. This deficiency is paramount at high levels and in many regional offices of EPA. There are no provisions in the approach to insure that qualified ground-water geologists or hydrologists will be involved. Academic training in ground water is presently oriented toward ground-water development and not pollution. Lastly, public participation is greatly limited by the general lack of knowledge regarding ground water and its pollution.Successful 208 programs in terms of ground water have been enacted when ground-water professionals have had major roles. Changes are necessary in the academic training of ground-water geologists and hydrologists. The public must be educated concerning the long-term consequences of ground-water pollution. Lastly, ground-water professionals must assume the leadership in ground-water protection.

Notes: It is herein submitted that the nearly universal phrase “shall not cause pollution of the ground waters and surface waters” written into the State regulations for waste disposal operations not only refutes a sound technical alternative, but is impractical, uneconomical and often unworkable.It is a fact that all ground waters are not created equal, as governed by certain irrefutable physical laws including the water budget equation and Darcy's Law which states that the quantity of ground water available is subject to wide variation from location to location. While an aquifer is a relative term, major, minor and nonaquifers can be identified within a given geographic area with respect to cost-effective ground-water resource development. Likewise, the natural quality of ground water is also a significant variable with certain parameters often exceeding drinking-water standards. The land application of wastes overlying the ground waters of an area should, therefore, also be subject to a certain degree of flexibility for prudent management of both the waste operation and the ground-water resources.Numerous investigations and empirical data can be cited to substantiate the fact that many wastes and their associated leachates can be safely assimilated into the environment with reliance on attenuation and controlled degradation of ground water by utilization of a mixing zone or zone of renovation with a specified distance from a disposal operation. As increased emphasis is placed on the land disposal/management of wastes/residuals and as the cost of these operations continue to mount, it is strongly recommended that controlled ground-water degradation be utilized in those areas where a “true” ground-water resource does not exist. Protection of such a “true” ground-water resource is obviously necessary as our demands for a potable water supply also continue to grow.

Notes: Ground-water computer models are, certainly, toys which provide intellectual stimulation. They can be useful tools for advancement of the ground-water profession, but I believe that they have been blown out of proportion and that this might cause irreparable damage to our profession.It is important to see where computer models fit into the ground-water problem-solving process. I believe that ground-water computer programs are simply a complicated “turn the crank” tool for making projections. They're one type of tool out of several which requires aquifer and confining bed characteristics to facilitate making projections. A second approach for making projections involves the direct extrapolation or manipulation of data which does not require transmissivity, storage coefficient, leakance, and other interpreted characteristics. Further, I believe that the collection and evaluation of data are of greater importance than the projection methods and/or tools in arriving at answers.Advantages of ground-water computer models include: speedy analyses once a program is working, ability to handle many parameters, and utilization of a large data base. The disadvantages include: use of computer models as end goals, tendency for misapplications, time-consuming setup, a waste of time and money in some cases, and diversion of human talent from useful ground-water work.

Notes: While it is true that waterborne diseases are still with us, and probably always will be, we cannot classify them as a current threat in the sense that they were 100 years ago. The discovery that chlorine would disinfect water supplies removed these diseases from a “current threat” category to the “historical lesson” category. We are not faced with unknowns which we are unable to attack. We have only to look at what others have done to protect themselves and follow the same or improved practices.If the record of waterborne outbreaks in public water supplies in this country from the end of World War II up to the present is examined, it will be found that all are caused by breakdowns in disinfection procedures or carelessness. The record is replete with statements such as “improper disinfection after repair,”“breakdown or lack of disinfecting equipment,”“back siphonage,” and other similar statements all pointing to failure to follow practices which the history of water treatment has shown to be necessary for protection against waterborne disease. Carelessness allows recurrence of disease outbreaks. If the lessons of history were followed, the conquest of waterborne disease transmission by public water systems could be complete.

Notes: The increasing use of ground water and its true role as a source of water supplies in the United States have sometimes been interpreted incorrectly. The total use of ground water has indeed increased tremendously during the last 20 years (by almost 80%), but so has the total use of water (over 70%). And ground water is still far from being a primary source of water supplies. In 1975, only 20% of the total amount of water withdrawn in the United States for various uses came from ground-water sources.Statistical analysis of ground-water data for the period 1950-1975 has shown that the ground-water usage is changing only very slowly. Relation of ground-water use to total water use expressed in percent was used as an indicator of changes of ground-water use patterns. This percentage has not changed significantly, and it has fluctuated around 19%. In 1975, only 6 States used more ground water than surface water for their water supplies, and in 23 States ground-water use was less than 10% of total use. Even more unfavorable is the magnitude of change in ratio of ground-water use relative to total water use. From 1955 to 1975 only 13 States show an increase in the ratio. In 28 States the ratio has decreased, and in 7 it has remained the same.

Notes: An objective view of the need for ground-water quality standards requires that an individual recognize the value that ground water contributes to the water supply needs of our nation. A vast number of people living in rural areas and a large number of communities are dependent upon ground water as their sole source of water for domestic, industrial, commercial, and agricultural needs.This large use and dependency upon ground water dictates that these resources are valuable and must be protected for both present day and future uses. There are many examples where present methods of disposal of wastes generated in America have not been satisfactory from an environmental standpoint, with an exception of projects where disposal sites have been properly designed, operated, and managed for protection of the ground water.One possible solution for ground-water protection is the establishment of ground-water quality standards. The purpose of such standards is to protect the public health and welfare and maintain the quality of ground waters in all usable aquifers for individual, public, industrial, and agricultural water supplies. A legal basis must exist and the prescribed steps must be followed as dictated by the rule making process. The primary aim of such standards is to prevent the degradation of ground waters such as they will not become a public health hazard or harm the users of the ground water.The backbone of such a standard rests on the completion of a hydrogeological study which is necessary to determine background water quality information, set up the monitoring program and outline sampling to determine when water quality changes are taking place and what is a significant change.

Notes: Half the population depends on ground water for domestic uses. Use is increasing 25 percent per decade. Ground water is generally used with little or no treatment.Some persons would transfer the discharge of our waste products from contaminated surface streams to the land and thus relatively clean ground waters.No standards exist that protect ground-water quality. Research necessary to give assurance that natural interaction of waste water and soils will remove, to acceptable levels, potentially harmful contaminants, organic and inorganic, that permeate today's waste streams and today's health concerns, has not been done.Success reports on land treatment of waste water have a not evaluated deterioration of ground water from organic contamination. Most waste waters contain synthetic organics in varying concentrations. EPA recommends their reduction in drinking water to the lowest possible level.Most instances of ground-water contamination have been discovered after drinking water is contaminated. Unless the public is willing to treat ground water as it does water from surface streams, greater control of land disposal practices must be exercised. Current practice does not indicate the necessary controls are contemplated or recognized. It follows that the widespread use of the land treatment alternative is, in reality, an accident waiting to happen.

Notes: The Nation's ground-water resources constitute a vast and often unprotected resource. The Environmental Protection Agency is about to launch a number of programs designed to protect what is, in many cases, a virtually non-renewable resource. Separate regulatory activities mandated under the Safe Drinking Water Act, the Resource Conservation and Recovery Act and the Clean Water Act must be carefully coordinated if they are to be effective.The current implementation efforts within the agency are being framed in view of our major principles which will be the focus of public comment in the months ahead. These principles are:First, the administration of the related programs will be a cooperative effort involving Federal, State and local governments, all of which must participate in formulating the program if it is to be effective.Second, the focus of the programs will be on the prevention of contamination rather than on its treatment at the point of withdrawal.Third, the applicable standards will be based primarily on technology rather than ambient ground-water quality considerations since the effects of discharges upon ambient quality are complex, difficult to predict, and of long duration.Fourth, there is a need to balance environmental protection, energy development and continued economic prosperity objectives so that the resulting programs fully protect public health while being realistically implementable.All of us—government, industry and citizens, through acts of commission or omission—have contributed to the potential problem. We must work together if we are to get on with the important task of protecting the quality of the Nation's ground-water resources.

Notes: Six types of vegetation were established successfully on lysimeters containing sanitary landfill materials. The vegetation grew well with the roots penetrating several refuse layers within one year. Leachate analysis indicated that vegetation and evapotranspiration (ET) reduced leachate volume and increased the rate of refuse decomposition. This was accompanied by production of a more potent leachate and a substantial increase in cumulative chemical oxygen demand. Therefore, this study suggests more potential ground-water pollution in a shorter period of time when vegetation is planted on a landfill. The net effect of ET on the stabilization of any particular landfill will be the result of a complex interaction involving climate, vegetation, soil type, cover material, landfill geometry, and other variables. This makes extrapolation of our results to a particular field situation rather difficult.

Notes: The anisotropic, areal hydraulic conductivity of the Felix No. 2 coal (Eocene, Wasatch Formation) has been defined in a four-well pump test at a site in the Powder River Basin of northeastern Wyoming. The direction of maximum hydraulic conductivity of the subbituminous coal bed bears N59°E and is associated with a horizontal hydraulic conductivity of 0.27 m/day. The direction of minimum hydraulic conductivity bears N31°W and is associated with a horizontal hydraulic conductivity of 0.15 m/day. The direction of maximum hydraulic conductivity approximately corresponds to the trend of the prominent face cleat in the coal, while the direction of minimum hydraulic conductivity corresponds to the trend of the butt cleat. The cleat orientation appears related to the alignment of major structural features of the region. Prediction of the direction of both maximum and minimum horizontal hydraulic conductivity in near-horizontal coal beds appears possible. However, either the cleat orientation of the bed or the alignment of the controlling fold structure must be known or obtainable.

Notes: The concept of the observation well as a measuring instrument with its own response characteristics is developed, and a method for response evaluation is derived based on methods of slug-test analysis. The effect of well response time upon the results of semiconfined aquifer tests is calculated and a series of type curves is produced. The ambiguity of observation well response affected leaky aquifer tests is demonstrated.A method for calculating well response time based on estimates of aquifer parameters and observation well dimensions is also presented to aid the proper design of aquifer tests. It is recommended that a slug test should be performed on every observation well used in confined or semiconfined aquifer tests.

Notes: The objective of this study was to develop surface electrical resistivity methods for estimating hydraulic conductivities in glacial outwash materials. Aquifer electrical resistivities were determined from the results of Schlumberger electrical soundings at six sites in southern Rhode Island where pumping tests had previously been made. Hydraulic conductivities and transmissivities determined from pumping tests were then correlated with resistivities obtained from electrical soundings. Results indicate that electrical resistivities determined from soundings can be used to predict aquifer hydraulic conductivities; an empirical relation between aquifer electrical resistivity and aquifer hydraulic conductivity was developed. A semiempirical relation between aquifer formation factor and hydraulic conductivity was also developed.

Notes: Long-term records of ground-water quality indicate that in an unsewered area of southeast Nassau County, New York, certain constituent concentrations increased substantially from 1910 to 1975. Most of the increases virtually parallel the rate of population growth and number of houses that discharge waste water through cesspools and septic tanks. Data sites used for this study were two abandoned infiltration galleries in Wantagh and Massapequa that withdraw water from the shallow aquifer. Ranges in constituent concentrations, in milligrams per liter, during 1910–75 were:

Notes: Subsidence of the land surface due to ground-water overdraft is caused by an increase in the intergranular pressure in unconsolidated aquifers and other underground materials. For unconfined aquifers, this increase is the result of a loss of buoyancy of solid particles in the zone dewatered by the falling water table. For confined aquifers, increases in intergranular pressure are caused by decreases in the upward hydraulic pressure against the bottom of the upper confining layer, due to a drop in piezometric surface. Compression of layers in which the intergranular pressure is increased can be calculated with elastic or logarithmic theory. Sample calculations yield rates of subsidence that agree with those observed, i.e., about 5 to 50 cm (2 to 20 inches) per 10-m (33-ft) drop in ground-water level. Ground-water depletion can also produce surface cracks, particularly above discontinuities in bedrock depth along the periphery or in other parts of subsiding basins. Calculations based on the rotating-slab theory show that the initial surface width of such cracks is about 1 cm (0.5 inch), which agrees with field observations.

Notes: Phosphate retention by soils is especially important for tile fields and rapid infiltration systems near lakes where eutrophication is a problem. The use and application of the phosphate adsorption isotherm test to estimate a soil's phosphate removal ability will be discussed. In New York State, the till soils had a greater phosphate retention ability than the outwash soils. Within the tills and within the outwashes, the more acid soils had a greater phosphate retention than the more basic or calcareous soils. The B horizon of many of the soils had a high phosphate capacity. However, this is often neglected in rapid infiltration systems because the waste water is discharged below the B horizon. The phosphate removal in column studies and field studies in rapid infiltration systems was found greater than predicted by the rapid isotherm test. Intermittent sand filters with two feet sand and underdrains were found to have a limited ability to remove phosphate. Methods to predict and design for phosphate retention by sands and soils are described.

Notes: The recent interest in the disposal of treated sewage effluent by deep-well injection into salt-water-filled aquifers has increased the need for proper disposal of salt water as more wells are drilled and tested each year.The effects on an unconfined aquifer of the improper disposal of salt water associated with the construction of three wells in southeastern Florida emphasize this need. In two of the wells provisions to prevent and detect salt-water contamination of the unconfined aquifer were practically nonexistent, and in one well extensive provisions were made. Of the three drilling sites the one with proper provision for detection presented no serious problem, as the ground water contaminated by the salt water was easily located and removed. The provisions consisted of drilling a brine-injection well to dispose of salt water discharged in drilling and testing operations, using a closed drilling circulation system to reduce spillage, installing shallow observation wells to map the extent and depth of any salt-water contamination of the shallow aquifer, and installing a dewatering system to remove contaminated ground water.

Notes: Generally the geology of the Breton area of Alberta consists of a 5-to 125-ft (1.5- to 38.1-m) veneer of glacial till overlying sandstone and sandy shale units of the Paskapoo Formation. These sandstone units are locally important aquifers. Glacial drift in the Hastings Lake area varies in thickness from 100 to 200 ft (30.5 to 61.0 m) and overlies the Horseshoe Canyon Formation, which consists of bentonitic shale, siltstone and coal units with minor sandstone units. Ground-water yields from drift and bedrock in this area are generally less than 30 gpm (113.6 1/m).Resistivity soundings were completed at 68 and 65 stations in the Breton and Hastings Lake areas, respectively. Profile maps from the Breton area are characterized by broad areas with apparent resistivity values greater than 100 ohm-ft (3048 ohm-cm). Qualitative evaluation of the resistivity soundings and existing borehole data indicated that the high resistivity values resulted from a thick resistive sandstone aquifer less than 25 ft (7.6 m) from ground surface. A reasonably well-defined resistivity pattern was evident on the profile maps of the Hastings Lake area with the highest resistivity values coming from stations located in the hummocky moraine south of the lake. Sounding curves and borehole data indicate that an increase in the sand content of the drift is responsible for these values. However, local variability in the drift lithology produces anomalies in the resistivity patterns. In addition to providing useful information on the geology of an area, surface resistivity methods provide a rapid and relatively inexpensive tool to aid in planning more detailed ground-water studies because of their ability to detect inhomogeneities in the subsurface environment.

Notes: Past ground-water quality monitoring programs have often involved sampling of low-capacity wells near point or line sources of recharge or pollution. However, large-capacity wells produce much of the ground water pumped for municipal, industrial, and agricultural uses. Short-term, seasonal, and long-term fluctuations in quality are common for water pumped from many large-capacity wells. In many cases, there is a considerable difference between in-situ “ground-water quality” and the quality of water sampled at the well discharge.Short-term pump tests for several municipal wells in the San Joaquin Valley, California have indicated that nitrate concentrations decreased exponentially with pumping time. Variability in pump operation creates substantial short-term changes in well-water quality. Short-term changes are most evident for infrequently pumped, shallow wells near point or line sources of recharge or pollution. Seasonal changes in quality have been documented for water from wells in areas of diffuse sources of pollution, such as agricultural return flow and septic tanks. These changes are primarily due to significant changes in depth to water and vertical hydraulic head gradient. Once the short-term and seasonal trends are established, the optimal sampling approach can be determined in order to establish long-term trends.

Notes: The effectiveness of basin ground-water recharge at the Leaky Acres Recharge Facility in Fresno, California for improving the regional ground-water quality was studied as 65,815,000 m3 of high-quality surface water was recharged from 1971 through 1975. Observation wells at the facility showed some variability in chemical parameters associated with each recharge period. The long-term decreases in salinity could be described by a power law decay curve fitted by regression analysis.Without a special network of observation wells outside the facility, scientific evaluation of the enclave of recharged water is not possible. A practical evaluation of water-quality changes is possible from producing water wells around the facility. However, the pumping well discharge-time variations, well depth, aquifer sequence, and prior use of surrounding land must be considered, since all of these factors affect the pumped-water quality and its seasonal variability. Recharge at Leaky Acres had noticeably decreased the ground-water salinity for a distance of up to 1.6 km in the direction of the regional ground-water movement.

Notes: One of the more subtle and dangerous areas of pollution is that occurring in ground water from normal irrigation practices. The pollution from salt buildup is presently one of the unsolved problems in managing stream-aquifer systems. This paper presents several strategies that offer a possibility of controlling this salt buildup. For example, instead of applying irrigation ground water near the site of the well, the ASTRAN Method transfers it downstream to be applied on land where the ground water is a lower quality thereby controlling the increase in salt concentration. Instead of preventing seepage loss in delivery canals, the percolating water is used to maintain ground-water quality. Finally, timed releases of return flow remove salts without exceeding surface-water quality constraints.

Notes: Small programmable calculators have recently become available that will allow many routine pumping or injection well calculations to be made rapidly, accurately and inexpensively. Programs and example calculations are given for the exponential integral and multiple well-multiple rate pumping or injection well equations using water well and oilfield units. The programs are for the TI 59 card programmable calculator.

Notes: Because of the relatively low stiffness properties of thermoplastic materials, casings made from these materials may be more susceptible to collapse. For many applications, when a surrounding material tends to support the casing, the casing resistance to collapse should be significantly increased. The Morley equations of equilibrium for two radial collapse pressure loading conditions were modified to include the support of the surrounding medium and were solved using the Galerkin method. Parametric studies were conducted for typical water well casings and restraint values. Simple collapse prediction formulas are proposed for predicting collapse for the two loading conditions considered. Collapse pressures predicted by the proposed formulas for uniform collapse pressure are approximately 25% lower than those values predicted by the current ASTM formula. Collapse pressures for linearly varying pressure were found to be 12% higher than the corresponding values for uniform pressure. When the radial stiffness of the surrounding medium is included in the analysis, the collapse pressure resistance of the casing was found to be significantly increased over the collapse resistance of an unsupported casing.

Notes: Precise geophysical surveys across ground failure zones related to ground-water withdrawal at nine sites in Picacho basin in south-central Arizona indicate that earth fissures in alluvium near exposed bedrock are spatially associated with local gravity and magnetic anomalies ranging from local highs to convex-upward changes in slope. We interpret the gravity anomalies, which range from 0.1 to 1 mGal with half-widths of 50 to 300 m (160 to 980 ft), to be caused by convex-upward irregularities in the bedrock surface underlying the alluvial aquifer. Most irregularities are inferred to be at depths less than 250 m (820 ft). Bedrock irregularities were not detected beneath failures that are more than 2 km (1.2 mi) from bedrock outcrop. The association of earth fissures with zones of variable aquifer thickness suggests that differential compaction is occurring near these fissures. Theoretical estimates, based on the finite element method, of horizontal strains generated by localized differential compaction suggest that this mechanism is the dominant source of horizontal tension causing earth fissures in Picacho basin. Our analysis indicates that tensile strains at fissures at the times of their formation ranged from 0.1 to 0.4 percent.Prediction of the location of earth fissures near exposed bedrock in Picacho basin and in adjacent basins with similar geologic settings appears feasible by delineation of convex-upward bedrock irregularities. Failures far from exposed bedrock, however, may not be as readily predicted on this basis. If the rheological properties and thicknesses of subsurface materials are known, prediction of the magnitude of water-level decline required to induce sufficient differential compaction to cause failure at potential earth fissures appears feasible.

Notes: On September 30, 1977, a large industrial plant in Fernandina Beach, Florida, shut down six artesian wells that had been pumping continuously for several weeks from the Floridan aquifer. Two wells continued pumping until November 20, 1977, at which time the shutdown wells were restarted. A water-level recorder on an observation well recorded the changing water level following shutdown and startup. Pumping rates of the wells ranged from 400,000 to 590,000 cubic feet per day (11,000 to 16,000 cubic meters per day). Distances from the pumped wells to the observation well range from 660 to 7,920 feet (200-2,420 meters). Analysis of the water-level data was further complicated because the wells were neither turned off nor restarted simultaneously; during recovery one well was restarted and pumped for several hours; and at the beginning of startup, a well that had been pumping continuously during the shutdown was turned off. The Cooper-Jacob graphical method, based on the principle of superposition and using values of specific drawdown or specific recovery (s/Q) and weighted logarithmic mean of the distance squared divided by time 〈inlineGraphic alt="inline image" href="urn:x-wiley:0017467X:GWAT525:GWAT_525_mu1" location="equation/GWAT_525_mu1.gif"/〉, was applied to determine the aquifer coefficients for the upper water-bearing zone of the aquifer. A transmissivity of 30,000 feet squared per day (2,800 meters squared per day) and a storage coefficient of between 2.5 × 10-4 and 4.0 × 10-4 were computed.

Notes: A sequence of simple statistical tests was used to interpret the data from a routine water sampling project for a stream that was contaminated with effluent from a sewage treatment plant. The contamination of this stream was apparent from the murky condition of the water and its pungent odor. The outlet of the sewage treatment plant enters the stream at its origin.The chemical variables analysed were Ca, Mg, Na, K, Cl, nitrates, TDS, and hardness. Background data from other streams in this drainage basin and data from the stream under investigation were subjected to cluster analysis in order to classify the sampled area into geochemical provinces. The contaminated stream under investigation comprised one province and the background streams constituted another province. A linear regression performed on the data showed a statistically significant decrease of several variables with increasing distance from the outlet of the sewage treatment plant. An abrupt decrease in concentration of iron some 450 m below the plant outlet implied the presence of two populations with different means, which was statistically verified with a trimmed t-test.Use of these simple tests greatly facilitated interpretation of the data.

Notes: Geochemical factors controlling water chemistry in an influent stream and adjacent flood-plain sediments were determined during a four-year study. The stream has a drainage basin that is similar to many streams draining carbonate terranes in the eastern United States. It receives sewage effluent, farm and urban runoff and supplies recharge to an aquifer under extensive development.Water beneath the flood plain, springs, and channel were calcium bicarbonate as expected; however, the prevalent chemical character of soil water beneath the channel was sodium bicarbonate. HCO3 within soil water beneath the stream is three times (1,500 mg/l) that beneath the flood plain, Na+ is two orders of magnitude greater (400 mg/l), K+ reaches 10 mg/l which is twice as great while CA2+ and Mg2+ may be one-fifth as high as concentrations beneath the flood plain with ranges from 15 to 20 mg/l and 5 to 10 mg/l respectively. Waters 3 to 7 feet (0.9 to 2.1 m) below the flood plain contain intermediate Na+ values from 25 to 75 mg/l.Ion exchange appears to be the mechanism accounting for the sodium bicarbonate water observed under the channel. The same relationship should occur in other areas with available carbonate rock, base exchange minerals, and an organic source.

Notes: From the 195O's to the early 1970's expansion of sanitary sewerage in southwest Nassau County contributed to progressive declines in ground-water levels. Since the early 197O's, however, 10 years after the area was fully sewered, water levels have not declined significantly, which suggests that the water table may have reached a new equilibrium position. Double-mass-curve analyses show that during 1953-76 the average weighted ground-water levels in a 32-square-mile (83-square-kilometer) part of the sewered area declined 12.2 feet (3.73 meters) more than those in the unsewered area to the east. However, by 1973 this decline was 13.5 feet (4.1 meters). Finite-difference digital-model results indicate that 3.6 feet (1.1 meters) of the relative 1953-76 decline was due to pumping in adjacent Queens County and that most of the remaining decline was a result of sewerage. Streamflow within the sewered area decreased in response to the lowered ground-water levels, and ground-water levels in the adjacent unsewered area were also lowered because of the sewerage.

Notes: One of the most valuable and practical tools the ground-water manager can use is the computer model, be it wellfield, conjunctive, solute transport, or statistical. Although these models vary in complexity, the end product is purely a function of the user's ability to select the appropriate level of modeling for a particular project. Any professional working in the field of hydrogeology should adapt to and use ground-water models to be truly efficient.

Notes: Land application of treated waste water can provide unique opportunities, not only for a final high level of waste-water treatment but for reuse of nutrients as well. Recent laws passed by Congress have made it necessary to consider land treatment when planning and designing new waste-water treatment facilities. The three types of land treatment commonly used are (1) irrigation, (2) overland flow, and (3) rapid infiltration. Selection of the most appropriate type of land treatment for a specific site is based on several considerations, including soil conditions, geology, topography, proximity to surface and subsurface water, and climate.Ensuring the protection of ground water is essential when siting or designing a land treatment system. Ground water is an important natural resource, having considerable impact on human life and well-being as well as high economic value. Safeguarding this important resource from contamination includes careful site selection, appropriate pretreatment of waste water prior to its application, and a program of regularly scheduled monitoring to ensure that the waste water is being properly renovated for safe release to the environment.Utilization of municipal sludge on land for agricultural production is encouraged by federal law, as is land treatment of waste water. Sludge contains concentrated wastes, and there are practical limitations on the levels of heavy metals, salts, and toxic substances in sludges applied to agricultural lands. Sludge is generally stabilized before being applied, to destroy pathogens, and reduce weight, volume and odor.Several case studies of successful land treatment systems presently in operation are presented to demonstrate the viability of the land treatment concept.

Notes: The system of flow into a nonpenetrating well with hemispherical bottom of finite radius in a finite deep artesian aquifer of infinite radial extent is analyzed. The solution is obtained in terms of error function. A method has been suggested for determination of transmissivity, storage coefficient and depth of aquifer from pump-test data of such wells discharging at constant rate. For small values of radial distance to aquifer depth ratio and for small duration test, only a few terms are required in the present solution as compared to the solution of Hantush (1957) developed for such wells.

Notes: The Pinellas Peninsula, an area of 750 square kilometres (290 square miles) in coastal west-central Florida, is a small hydrogeologic replica of Florida. Most of the Peninsula's water supply is imported from well fields as much as 65 kilometres (40 miles) inland. Stresses on the hydrologic environment of the Peninsula and on adjacent water bodies, resulting from intensive water-resources development and waste discharge, have resulted in marked interest in subsurface storage of waste water (treated effluent and untreated storm water) and in future retrieval of the stored water for nonpotable use. If subsurface storage is approved by regulatory agencies, as much as 265 megalitres per day (70 million gallons a day) of waste water could be stored underground within a few years, and more than 565 megalitres per day (150 million gallons a day) could be stored in about 25 years. This storage would constitute a large resource of nearly fresh water in the saline aquifers underlying about 520 square kilometres (200 square miles) of the Peninsula.The upper 1,060 metres (3,480 feet) of the rock column underlying four test sites on the Pinellas Peninsula have been explored. The rocks consist chiefly of limestone and dolomite. Three moderately to highly transmissive zones, separated by leaky confining beds, (low permeability limestone) from about 225 to 380 metres (740 to 1,250 feet) below mean sea level, have been identified in the lower part of the Floridan aquifer in the Avon Park Limestone. Results of withdrawal and injection tests in Pinellas County indicate that the middle transmissive zone has the highest estimated transmissivity-about 10 times other reported values. The chloride concentration of water in this zone, as well as in the two other transmissive zones in the Avon Park Limestone in Pinellas Peninsula, is about 19,000 milligrams per litre. If subsurface storage is approved and implemented, this middle zone probably would be used for storage of the waste water and the zone would become the most extensively used in Florida for this purpose.

Notes: Land subsidence increases the area in the Texas Coastal Zone which will be inundated by marine waters from hurricane flooding. Storm surge from a Carla-sized hurricane in 1976 would flood at least 25 square miles (65 km2) more land than Hurricane Carla did in 1961.Land subsidence in Harris and Galveston Counties results primarily from ground-water production. The two-county area is interlaced with active surface faults with topographic escarpments and surface faults with no topographic escarpments that control drainage patterns and create subtle photographic linear patterns. Ground-water production activates these faults by differential compaction of the aquifer. The faults appear to be partial hydrologic barriers that compartmentalize land subsidence into several individual basins.

Notes: Disposal of industrial process water into an unlined lagoon in permeable Atlantic Coastal Plain sediments resulted in a ground-water contamination problem caused by infiltration of the process water into a major unconfined aquifer which underlies the lagoon at shallow depth. Most of the area water-supply wells terminate in this formation. Before this disposal method was discontinued, traces of the process water appeared in nearby wells.Because of the relatively large area and depths involved, as indicated by preliminary data, delineation of the distribution of contaminant within the aquifer through a systematic well drilling program posed a significant economic problem. To keep costs within a reasonable range, a resistivity survey program was implemented to obtain information on the gross distribution of the contaminant and to provide data for the selective location of monitor wells. Eight wells were constructed to obtain samples of the ground water in order to measure contaminant concentrations and to verify the interpretations of areal contaminant distribution inferred from the resistivity data. The ground-water sampling procedure developed during this investigation is described.The combination of the resistivity survey with the ground-water sampling procedure developed during this investigation proved a valuable and reliable technique for delineating in three dimensions a contaminant body within an aquifer in unconsolidated sediments. Utilization of the resistivity survey data to selectively locate the monitor wells and to define the lateral extent of the contamination increased the efficiency of the investigation and significantly reduced the cost of the program.

Notes: A study of toxic trace metal distribution in ground waters of the Front Range mineral belt, Colorado and adjacent areas was performed in order to determine the relationship of water quality to mineralization and the magnitude of potential health effects. A total of 149 samples were collected and analyzed for arsenic, cadmium, copper, iron, lead, manganese, mercury, silver and zinc. Field determinations of pH, Eh, and specific conductance were also made.The trace element data exhibited a lognormal distribution and are described utilizing the geometric mean and geometric deviation. Four populations were recognized in the samples: (1) samples in the mineral belt with plumbing contamination; (2) samples in the mineral belt without plumbing contamination, (3) samples outside the mineral belt with plumbing contamination, and (4) samples outside the mineral belt without plumbing contamination. Differences in these populations for several elements are observed utilizing the t test.Utilizing the observed data distributions, geochemical abundance estimates are made for the four recognized populations. The data distributions are corrected for analytical error, corrected for determinations below the detection limit and expressed as a predicted central 95% range for each element in each population. The corrected geometric mean, corrected geometric deviation, along with the U.S. Public Health Service limit for each element determined are used to determine the probability of ground water exceeding the specified limit for each constituent. Ground waters in the mineral belt are estimated to exceed the U.S. Public Health Service limit in 14% of the samples for Cd, 1% for Cu, 51% for Fe, 74% for Mn, 2% for Hg, and 9% for Zn. Ground waters outside the mineral belt have a similar probability of exceeding the limit for Hg and lesser probabilities for all other elements.

Notes: A 120-acre sanitary landfill site is being developed in north-central Pennsylvania to serve a six-county area. The design of the site will prevent ground-water contamination by leachate from the refuse through the use of a 20-mil (.5 mm) PVC plastic liner which will lie between two protective layers of sand containing drainpipe networks.Sampling of the composite ground-water flow from the underdrainpipe network in the sand blanket under the liner will provide sensitive monitoring of the liner performance. In the unlikely event of a leak, the pipe draining that area would be diverted to the leachate treatment facility, thus providing a backup leachate collection system. A thick (15 to 75 feet, 4.6 to 22.9 metres) glacial till deposit is present at the site and confines ground-water flow within the underlying shale bedrock. The low permeability of the till and the artesian head within the bedrock flow system provide additional protection against ground-water contamination.Operation of the site will be by the area-fill method; the refuse will be deposited in 8-foot (2.4-metre) lifts up to a maximum height of 120 feet (36.6 metres). Based on an initial refuse deposit rate of 400 tons (363 metric tons) per day, the site is expected to have a 20-year life at a disposal cost of approximately $5.00 per ton.Local residents who felt this project posed a severe threat to their wells strenuously opposed the project and appealed the State permit. The Pennsylvania Environmental Hearing Board upheld the permit; the decision was appealed to Commonwealth Court and was upheld. Residents remain unconvinced the design and site conditions will provide adequate protection and have petitioned the Pennsylvania Supreme Court to consider another appeal.A baseline water-quality monitoring program has been undertaken to establish on-site conditions and a private-well sampling program will begin before the landfill is in operation. Till and bedrock monitoring wells at the site will be used to evaluate the performance of this landfill; analysis of the nearby private wells will be provided to the owners to demonstrate confidence in the design and the satisfactory operation of the ground-water protection measures.

Notes: The best potential aquifers underlying the 600 mi 2 Hualapai Plateau of northwestern Arizona are (1) the Cambrian Rampart Cave Member of the Muav Limestone and (2) interbedded Tertiary sedimentary and volcanic rocks that locally fill old canyons on the plateau. These target aquifers have been identified on the basis of spring locations on the flanks of the plateau, primarily along the walls of the Grand Canyon to the north and east. Total ground-water discharge from springs along the plateau is approximately 4 ft3/sec.To date the largest production from a test well on the plateau is 120 gal/min from Tertiary rocks. The Cambrian rocks have frustrated development in part because of small permeabilities, small recharge (0.1 in/yr minimum), and the fact that the rocks are well drained.The complex stratigraphic nomenclature used to describe the Cambrian rocks in the region has inadvertently contributed to prospecting failures. The Cambrian section is characterized by thick interbedded limestones and shales, with the basal limestone being the principal target aquifer. These relationships have not been adequately conveyed to managers and drillers, with the result that critical test holes have been terminated in shales that overlie the target aquifer. Dry holes have been the result.

Notes: Control of epidemic waterborne disease of an infectious nature has been made practical through modern drinking-water treatment practices. Certainty of such control depends upon treatment plant reliability. The possibility of the transmission of newly recognized infectious diseases by the water route must be considered. The presence of trace amounts of chemicals in drinking water that are potential agents of chronic disease, particularly cancer, poses many questions concerning the safety of our water supplies.

Notes: Few would argue that ground-water pollution is a problem and that serious ground-water pollution problems do exist. As serious as some isolated ground-water pollution problems are, regionally and nationally, it is only a limited problem. An industrial landfill may result in a leachate plume contaminating ground water over an area of up to several square miles downgradient from the disposal site. Municipal landfills or chemical/petroleum spills can result in polluted ground water over areas measured in square miles. Surrounding these areas of ground-water pollution, however, are tens and hundreds of square miles of area where the ground water moving through the aquifers maintains its natural good quality. The ratio of good quality to contaminated water is such that ground-water pollution can really only be considered as a limited problem.The problem will most likely remain limited as existing and future regulations continue to restrict the poor disposal practices that have been responsible for much of the past and existing pollution problems. Technology has advanced to the point that with proper management and sound governmental regulations, control, isolation and cleanup of contamination sources and areas of polluted ground water can be so effective that migration of the pollution front can be stopped and actually reversed with time.The same technology that provided us with the new chemicals and the wastes that show up in water analyses, has also provided us with the means of detecting many more contaminants at much lower levels of concentration in a water sample than was possible 50, 25 or even 10 years ago. One must thus ask, has ground-water pollution really become a national crisis, or do we just know more about an old problem made apparently more complicated by our own technological advances?

Notes: Proposals to establish national ground-water quality standards appear to be premature, and redundant because of the geohydrologic and geochemical factors governing the occurrence and development of ground water. Although it can be reasoned that there is no “good time” to establish additional governmental standards (and the resultant additional governmental regulations), it can also be strongly argued that now is a “bad time” to consider establishment of the proposed standards.First, a present mood of the general public is away from more governmental involvement in the business and private sectors, and a rebellion against the increasing cost of government. Second, the applicability and workability of present Federal (and some State) laws that could be used to adequately protect ground-water quality, have yet to be implemented or otherwise sufficiently tested.The full force and effect of the Water Pollution Control Act (PL 92-500 with amendments) has yet to be implemented, and Congress is still considering its “oversights” in their drafting of same.The Safe Drinking Water Act (PL 93-523), particularly those sections designed or usable to protect ground-water quality, have yet to be tested by the EPA. Like PL 92-500, the deadline for implementation of parts of PL 93-523 has long since passed.And the far-reaching effects on ground-water quality protection that three other federal laws-the Resource Conservation Recovery Act (PL 94-580); the Toxic Substances Control Act (PL 94-469); and Surface Mining Control and Reclamation Act (PL 95-87)—are totally unknown, since the procedures for full implementation of these acts have yet to be developed.Therefore, it appears that establishing a new ground-water quality control act prior to testing existing law and thereby learning from their flaws or shortcomings, could result in unnecessary proliferation of law without its reasonable testing.This appears to be good time to interrupt the geometric progression that tends to spawn additional laws when laws are developed ahead of their established need.Equitable and workable ground-water quality protection could be fostered through the enactment of the long overdue requirements for the integration of surface-and ground-water development and management structures. This integration would decrease inefficiency of use of these water resources—which are actually inseparable in identity to their users, the American taxpayers.

Notes: Recent research has expanded our understanding of the suitability of waste disposal in various hydrogeologic settings. Although more research is needed, our knowledge can provide a basis for preparing guidelines for action that will protect ground water from waste disposal practices. It is impossible, however, to prevent accidental spills, unlawful dumping, and ground-water contamination or pollution resulting from some old, unregulated waste disposal practices. Therefore, more than 170 case histories of subsurface contamination or pollution were studied to evaluate the effectiveness of remedial action in different geologic environments. The case studies indicate that the severity and extent of ground-water contamination is determined by (1) the hydrogeologic setting, (2) the nature of the contaminant, and (3) the effectiveness of regulatory action.Industrial wastes are the most common sources of ground-water contamination. The most serious incidents are those that pollute or threaten water supplies and those that cause a fire or explosion. Once ground water is contaminated, remedial action is time consuming and expensive. Each incident must be handled as a separate problem. Although prompt action is essential to limit contamination and minimize remedial action, no strategies have been established for rapid response to contamination or pollution problems.Ground-water contamination will continue, but its impact can be reduced. The role of hydrogeologists in regulatory agencies should be strengthened to provide proper evaluation of potential sources of contamination and to aid in remedial action when ground water is contaminated. Cooperative efforts to develop strategies will ensure proper handling of future emergencies.

Notes: The opportunity to begin formulating a national ground-water quality protection program is at hand. In building the new program we should use the host of lessons learned in the experience of related environmental programs. This is necessary so that the new program will be realistic at the outset and congruent with the integrated planning and management of the ground- and surface-water resources of the nation.The keystone of program development, implementation, and evaluation is and will continue to be water quality standards. To the extent that the goal “Safe Drinking Water for Americans” has already been established, the point-of-use regulations (IPDW Regs and the RPDW Regs), should serve as water quality objectives thus facilitating ground-water program formulation and evaluation. The major regulatory thrust of the program, the water quality standards, must be technology-based site selection, construction and operational standards, with only limited monitoring in a conventional water supply and water pollution control context.

Notes: The necessary administrative mechanisms for protection of our underground drinking water sources, and coordination of natural resource and energy development and environmental quality programs, should be provided by a federal ground-water control program, else today's underground contaminant disposal activities will be tomorrow's undoing. Federal regulations, however, must provide flexibility to States and industry to find the least costly means of meeting national environmental goals.A growing body of literature clearly documents cases of underground drinking water source contamination, sometimes severe, from a large variety of conditions and practices. Existing studies also indicate that this problem is pervasive: aquifers have been adversely affected in every region of the country.A federal ground-water protection program which (1) reflects consideration of total long-range natural resource protection and environmental quality benefits, (2) regulates in a manner so that the benefits to the environment generally exceed the regulatory costs and (3) encourages more efficient ways of meeting environmental goals in the least costly manner can and must be developed by the Environmental Protection Agency. Without an effective Federal ground-water protection program, the underground contamination problem will likely worsen.

Notes: In early September 1975 a Technical Committee was established by the Virginia State Department of Health to clean up and dispose of a manufacturing plant which had produced the pesticide Kepone, in Hopewell, Virginia. The Committee recommended that the hazardous wastes be buried in a virgin section of the new City of Hopewell landfill. The disposal pit was designed to encapsulate the wastes in clay and plastic. The project was completed in early March 1976. The disposal site is monitored by the Virginia State Water Control Board via an observation well and an underdrain system.

Notes: The construction of wells yielding safe, sanitary water in areas of severely folded, fractured, and creviced limestone depends on the retention of enough sediment in the transmission paths to restrict the movement of contaminants. The described research has been directed towards two problems–the identification of terrain and hydrologic features that indicate a lack of adequate sanitary protection of ground water in the formation, and means of improving this protection. Intermittent spring-sinks along streams or in low-lying areas indicate a reversal of ground-water flow in the area. When the water level rises above a critical level sediments that have accumulated in the formation over many years may be discharged in a few days, resulting in a loss of filtering ability.Ground-water levels and bacteriological contamination have been monitored on four wells in Washington County, Maryland, since 1973. Ground-water quality deteriorated after tropical storm Agnes washed sediments from the formation. Techniques for preventing surface contaminant entry, improving filtering ability of the formation, and providing controlled relief of hydrostatic pressure have been studied as ways of protecting ground water in the formation.

Notes: The modelling of the Uluova Plain in southeastern Turkey was a part of training offered to Turkey's State Hydraulic Works' staff within a UNDP project. The modelling of the 341-sq km plain started with the simple steady-state version, but the model was gradually made more and more complex. At the end of modelling, the entire ground-water system was subjected to various automatic controls. The interesting feature of the model was the interaction between surface water (Keban Reservoir) and ground water. Lake Keban started encroaching upon the plain in 1974 and by the middle of 1976 it occupied over 100 sq km of the plain. In its verification phase covering the period from 1967 through 1974, the model amended the conclusions from a previous hydrogeological study. In its prediction phase, the model simulated the ground-water extraction plans for the 1976–1985 period. The modelling showed that the planned increase in ground-water withdrawal from about 17 million cubic meters (MCM) in 1975 to about 30 MCM in 1976 was quite realistic and completely sustained by the aquifer. The maximum drawdowns in the 1974–1980 period are of an order of magnitude of 20 meters. Another sharp increase in ground-water development from 30 to 58 MCM that was foreseen for 1981 would create drawdowns in some areas in excess of 35 m. The results of modelling pointed at several possible management alternatives.Several computation runs, which were repeated with Lake Keban removed from simulation as if it had not existed, made possible the evaluation of actual effects of the lake on ground-water development potentials of the plain. It was demonstrated that the lake improved the situation appreciably over an area of about 48 sq km that was foreseen by planning for additional development.The Uluova model incorporates some advanced and new routines in integrated surface-water–ground-water simulation.

Notes: The electrical resistivity method has been used to delineate shallow zones of ground-water contamination resulting from solid waste disposal sites. Application of this method to sites located in alluvial deposits in Iowa revealed that the degree of success of the method was directly related to the degree of contamination. A detailed investigation of the interrelationship between electrical resistivity, material variation, and water quality was conducted in the alluvial deposits of the Skunk River at Ames, Iowa. The lateral variation of materials at this site resulted in a large, natural scatter in the resistivity response. The decrease in resistivity due to contamination was not greater than this natural scatter and thus could not be detected. These results suggested a relationship between the scatter levels at any site and the minimum degree of contamination necessary to be detected. The minimum level of contamination which can be detected over the natural scatter is herein called the threshold value. The threshold value must be known before the resistivity method can be applied with confidence.

Notes: Mathematical modeling of regional unconfined ground-water flow is most often accomplished by using a linearized Dupuit-Forchheimer (DF) equation. The depth of flow, h, in the general DF equation appears as a squared (h3) term and also as a linear term (h). Linearization of the DF equation is generally accomplished with the first method of linearization presented by Polubarinova-Kochina (PK), in which h2 is replaced with h times some average depth of flow. The resulting equation is then linear in h. The second method of linearization described by PK is accomplished by replacing h with h2 divided by an average flow depth, and hence the resulting equation becomes linear in h2. If the second method of linearization is used, the same “heat conduction type” equation is obtained as that from the first method of linearization, but it tends to yield more accurate predictions of water-table locations. Furthermore, by simply altering the numerical values of boundary condition constants, most existing mathematical models, based on the first method of linearization, can be easily converted to yield solutions to the more accurate equation linearized by the second method.

Notes: An analysis of the unsteady flow in a fresh-water lens on a small tropical island is developed using the Ghyben-Herzberg relationship to determine the lens thickness. An alternative view of the problem to that most commonly given is presented. Results are shown for some lenses on Grand Cayman Island in the Caribbean Sea. The aquifer material is a micro-karst limestone. The chief result of engineering significance is that the conventional steady-state analysis is shown to be a sound basis for estimating the long-term yield if drought sequences are not long.

Notes: The hydraulic characteristics of a layered ground-water system are determined by a modified digital model. Its use provides information on the hydraulic conductivity and storage coefficient of a stratum and on the transmissivity and storage coefficient of the ground-water system as a whole. These characteristics are determined by trial-and-error test runs until the calculated drawdowns reasonably match drawdown data from observation wells which are open to the artesian aquifer and to the confining beds above or below. An aquifer test of a layered ground-water system in Palm Beach County, Florida shows that the transmissivity of the ground-water system as a whole is 50 percent higher than just the transmissivity of the major water-bearing zone in this system.

Notes: The danger from salination poses a significant threat to development of ground-water resources for domestic or irrigation use in near-coastal environments throughout the world. The Dashte-Naz farm area near the Caspian Sea in northern Iran is no exception. Large-scale ground-water development in this region has been limited to wells south of the Caspian Sea near the base of the Alborz mountains where sediments are coarse and natural recharge high. In the northern regions, however, exploitation of the groundwater resources for agriculture and livestock purposes has proven fruitless with most of the high-yielding wells turning saline after only several irrigation pumping seasons. The source of the salination comes not from encroachment of Caspian Sea water but rather from sediments saturated with connate or fossil waters. A wide zone of dispersion separates the salinated aquifers from the fresh-water aquifers nearer the mountains.The Dashte-Naz ground-water barrier and recharge project was conceived for purposes of overcoming the problem of exploitation of fresh ground-water reserves in the vicinity of saline-water fronts. The project presently under construction is a pilot research project on the practicality of using an injection well barrier for storing water underground in areas immediately adjacent to saline ground-water reservoirs. The results from this project will be used to design other water-supply projects in Iran not only

Notes: A plume of contaminated water may extend downstream for several miles in an alluvial aquifer. Hydrologic forces acting on the aquifer generally tend to dilute the contaminant downstream from the source. After the pollution has been stopped, how rapidly will these hydrologic forces flush out the contaminant? The answer to this question may be calculated by using the mass-balance equation herein developed.This mass-balance mathematical model incorporates all the hydrologic forces acting on the alluvial aquifer that affect the concentration of the contaminant. Methods are presented to define and quantify each of the hydrologic forces. These forces include (1) present quantity and quality (with respect to contaminant) of water in the alluvium and the change in the quality downstream, (2) quantity and quality of ground-water inflow, (3) quantity and quality of flood inflow, (4) quantity and quality of base flow, (5) quantity of recharge from precipitation, and (6) quantity of loss from evapotranspiration.The equation is first balanced to agree with past conditions and observed field data and is then used to predict future quality changes after the pollution is stopped.The method is applicable primarily to situations in which the pollution has been taking place over a long period of time and the water quality in the alluvium has reached equilibrium at any given point. Modifications may be possible to permit use of the general approach to short-term or slug-type pollution events.

Notes: Overexploitation of ground water in Krishni-Hindon interstream region (Lat. 29°05′N–29°29′N and Long. 77°19′E–77°32′E) in Uttar Pradesh, India, prompted us to carry out aquifer modeling studies. The area lies in Gangetic alluvial plain. The interconnections in the phreatic aquifer and the lower semiconfined aquifer led to the assumption of a single-story aquifer for which an R-C analog model was constructed.The input-output quantities in the model have been simulated using current/voltage generators and current sinks which are appropriately programmed in time-domain with the help of wave-form synthesizers for a realistic representation of the field system.The model study shows that the aquifer can sustain the present output rate of 200 mcm/year without much damage to the ground-water regime. In another scheme, an annual increase of 5% in exploitation rate, shows deleterious effects on the aquifer. Decreased rainfall/droughts would worsen the situation.The influence of hydraulic connectivity between the aquifer and the Krishni-Hindon river system is quite significant. If the present exploitation rate were to continue for 20 years, the annual inflow to the aquifer from rivers is estimated to increase by about 36.0 mcm.More hydrogeological data is required for further validation and refinement of the model.

Notes: In order to regulate the use of ground water, State agencies and local government, together with local public participation, have developed a management policy which is now being implemented in Nebraska. A water-resource agency, a geological survey, and a local, multi-county governmental unit are combined with several other governmental units to investigate water problems and guide a variety of vested interests toward a common goal of efficient water-resource management. The key government document delegating the authority and guiding the agencies is the Nebraska Ground Water Management Act of 1975. This Act specifies a procedure whereby local residents concerned about misuse and depletion of their ground-water supplies can request that official hearings be held, water-supply evaluations be made, and consideration be given by the Nebraska Department of Water Resources to establish what is called a “control area.” Designation of a control area allows development and enforcement of methods to deal with the water-resource problem within that area. The management alternatives provided for by this Act include well spacing, rotation of pumping, allocation of water, and moratoriums on drilling. The Act does not, however, address conjunctive use of surface water and ground water, guidelines for management policies, and rights to artificially stored ground water.

Notes: An important aspect of the pollution of a phreatic aquifer by hydrocarbons is the oil-water contact and transfer of soluble substances from the oil into the ground water.A systematic study of this transfer of matter in a saturated porous medium (initial condition of contact when the impregnation body is submitted to fluctuations of the piezometric level) is performed with an experimental device made up of a porous matrix containing the oil phase, steady and crossed by a unidirectional flow of water. The transfer is very efficient; for all compounds which have been studied, the maximum possible concentration is reached after a distance of the order of 10 cm with specific flow rates greater than those generally encountered in a gravel-sand aquifer. The selective impoverishment of the oil product with time, due to differences in the solubility of various hydrocarbons, modifies the dissolved phase composition. Downstream of an in-situ impregnation body, this phenomenon only appears after a constant concentration has been reached for a long time. A source model is thus obtained, where the pollutant massic flow rate is proportional to the flow rate of the water which crosses the impregnation body. Such an initial condition has a fundamental effect on the determination of the contaminated aquifer domain, with the help of the dispersion scheme, with hydrocarbon concentrations evolving according to a general diffusion-convection law.

Notes: Increasing population and industrial development in northwestern Ohio indicated the need for an evaluation of the bedrock ground-water resources of the region. A digital ground-water model was designed and used as a tool for predicting water-level declines resulting from projected ground-water withdrawal. Potentiometric surfaces, keyed to historic, accelerated, and peak projected ground-water withdrawals, were predicted by decades to the year 2036. These withdrawals at the calculated rates will cause severe overdrafts at Lima, Toledo, and Findlay, Ohio, and at Ft. Wayne, Indiana, by the year 2036.

Notes: The artesian Casper aquifer, comprised of 700 ft of interbedded limestones and sandstones, currently supplies 70 percent (3.5 Mgal/d) of the municipal-water needs of Laramie, Wyoming. Large transmissivities occur in fracture zones associated with faults and folds in the area, and water discharges from several springs localized along these structures. Transmissivities in fracture zones are 100 times greater than those in unfractured parts of the aquifer. The overlying Satanka Shale is a regional confining unit even in most areas of fracturing, and is a source of poor quality ground water. Prospecting for new ground-water supplies near Laramie involves mapping the tectonic structures and drilling into them once they are identified.

Notes: Data from over 800 well samples collected and analyzed during a study of ground-water quality in Sussex County, Delaware revealed that the water-table aquifer contains excessively high concentrations of nitrate in several areas. Over 20 percent of the wells sampled contained concentrations that exceeded 45 milligrams per liter (mg/l), and in many areas, over 50 percent of the wells sampled exceeded 45 mg/l.Sussex County is part of the Atlantic Coastal Plain Province, geologically consisting of a series of unconsolidated sands, gravels, silts, and clays that contain extensive ground-water reserves of generally high quality. On the basis of iron and nitrate concentrations, two major areas of differing water quality were delineated: one in which the ground water contained variable concentrations of nitrate with low concentrations of iron (〈0.2 mg/l), and another in which it contained large concentrations of iron (〉2.0 mg/l) and little detectable nitrate.Nitrate concentrations ranged from zero to 224 mg/l; average and median values determined for the area of nitrate occurrence were 33.9 mg/l and 25 mg/l respectively. Treatment of the nitrate data allowed depicting of 19 areas of possible excessive nitrate contamination. Nitrate occurrences were closely related to land use, soil permeability, water-table depths and aquifer chemistry. The greatest incidence of high nitrate concentrations was associated with confined feeding operations. Other nitrate sources are septic tank effluent, natural and chemical fertilizers, foliage in forests, and precipitation.

Notes: Lubbock is located in the center of the semiarid High Plains of Texas. Due to a shortage of adequate water-based recreational facilities in the region, the City Planning Department developed a scheme for converting an eight-mile intracity canyon into a linear park containing a series of small recreational lakes. Funds amounting to over 11 million dollars were committed to the project by a local bond issue and various governmental organizations.The proposed lake makeup water is unique. Never before has a serious attempt been made to develop recreational lakes utilizing urban runoff and twice-used reclaimed municipal waste water as the sole source of supply. The majority of the makeup water will be obtained from wells on a farm which has received the major portion of Lubbock's secondary treated sewage since 1938 and used it for irrigation purposes.In order to ascertain the suitability of utilizing this reclaimed sewage effluent for recreational purposes, the Texas Tech University Water Resources Center with the aid of an OWRT grant constructed a model system designed to simulate the lake project. Research performed to date includes algal growth potential studies, water quality analyses, bacteriological assays, viral assays, and fish life studies.

Notes: An attempt was made to locate ground water in an arid, mountainous area in the Santa Catherina region of southern Sinai. A combination of classical geological methods, together with geophysical techniques was found to be particularly useful for the locality studied. It was found that water flow was mainly through the joints of the crystalline basement and that under favorable circumstances, fair ground-water supplies can be found in alluvial valley fill. It was concluded that recharge of valley fill is derived mainly from the joint system of the bedrock and only partially from flooding.

Notes: Cement grout surrounding a well casing generates heat, called heat of hydration, as it hardens. This heat can raise the temperature of the casing-grout-soil system significantly. Because the strengths of plastic casing materials decrease relatively rapidly with increasing temperature, it is important to have some idea of the temperature increase to be expected. Solution of the radial heat-flow equation predicts temperature rises at the outer casing boundary of 9°C (16.2°F) to 55°C (99°F) as the grout envelope around a 6-inch, water-filled casing varies from 1.5 inches to 12 inches. The time required for the peak temperature to be reached varies from 7 to 22 hours. The temperature increase is relatively insensitive to casing diameter and thermal properties of the casing and soil. It is relatively sensitive to the type of cement used in the grout and the material filling the casing while the grout is curing. All types of plastic casing have been used successfully for years. This is due partly to the fact that in most grouting operations from the bottom up, forces on the casing are such that there is little or no tendency for collapse. However, if an air-filled, plastic casing were grouted from the top down, heat-induced collapse would be much more likely, particularly in zones where caving took place during well drilling.

Notes: During 1976-1977 nitrate-nitrogen (NO3-N) concentrations exceeded 10 mg/1 in 183 of the 256 ground-water samples collected from parts of Buffalo, Hall, and Merrick counties in Nebraska. Comparison of the isotopic values with those of potential nitrate sources suggested that the primary source of contamination in most wells was fertilizer and that a small percentage of the wells contained significant concentrations of NO3-N derived from animal wastes. A combination of two or more sources of contamination was assumed for those samples for which the source could not be identified. Significant negative correlations between δ15N and NO3-N (-0.35 in Buffalo and Hall Counties) and between δ5N and depth to water (–0.55 in Merrick County) indicate that denitrification is the major factor in isotopic fractionation of nitrogen from the nitrate sour

Notes: The benefits of employing the 208 planning approach in the protection of surface water or ground water are twofold—one, involvement of the public early in the planning process and two, determination of solutions that are implementable. With increased public awareness precipitated by the required involvement in Water Quality Management Planning (WQMP), the ensuing public interest will ultimately force ground-water issues which have been neglected for many years. The preparation of a “5-Year Strategy” in each State coupled with USEPA's new emphasis on aquifer protection as a priority issue will provide the mechanisms for funding ground-water planning under 208 programs. As the cry for ground-water management planning is adopted by the public as well as technicians, emphasis will shift and programs will develop. In addition, planning programs under 208 are usually regional in nature in contrast with the ground-water studies in recent years which have been site-specific, directed toward the identification and alleviation of local problems. Since the management approach requires that the evaluation of available alternatives include those mechanisms necessary to implement the recommendations, viable alternatives without either management agencies or financial considerations will not be acceptable. Therefore, the strength of the WQMP approach to ground-water protection lies in those concepts that make planning under 208 a new breed of governmental program.

Notes: Man's activities are an ever-increasing threat to ground-water quality. New EPA policies encourage cities to discharge sewage effluent on land. Irrigated agriculture is incompatible with high-quality ground water where deep percolation water is not removed by drainage. Present drinking-water quality standards cannot be used to determine the suitability of water for potable use if such water is waste-water-derived. Where sewage effluent is applied to land, persistent trace organics occur in underlying ground water. Some of these organics may be carcinogenic or otherwise toxic, and much additional research is needed. Controlled degradation of ground water still is degradation. High-quality ground-water resources either are to be protected, or aquifers eventually must be abandoned as sources of high-quality drinking water. In the long term, there is no in-between. The choice will be dictated by economic and environmental considerations. For example, the most economical use of aquifers below irrigated valleys ultimately may be to serve as facilities for treatment, storage, and conveyance of municipal waste water from surrounding communities, so that this water can be used again for unrestricted irrigation. While such uses of aquifers may be far off, they should be anticipated now to allow proper planning.