ALBERT

Notes: Although more than 60 million individuals rely upon the absence of microbial pathogens in their marginally-treated or untreated ground-water supplies, an analysis of reported waterborne disease outbreaks for the period 1946-1970 shows that contaminated ground-water supplies were responsible for over 50 percent of the outbreaks. Completed ground-water studies indicate: (1) coliforms and fecal coliforms are present in a significant percentage of improperly located or inadequately protected private supplies, and (2) the apparent absence of coliforms due to the insensitivity of currently available bacteriological methods does not preclude pathogen occurrences. Excessive bacterial populations, normally not encountered in finished water, can suppress coliform detection. For this reason, it is essential that improved bacterial detection methods be developed and other criteria for untreated ground water be explored by comprehensive field investigations and laboratory analysis of ground-water supplies for a variety of bacterial parameters.

Notes: The ground waters of Runnels County, Texas, are highly contaminated with nitrate. The average nitrate concentration of 230 water samples was 250 mg/I NO3.The natural variations of the stable nitrogen isotopes N14 and N15 identified natural soil nitrate as the predominant source. Nitrate from animal wastes was of minor importance. The δN15 range of natural soil nitrate was +2 to +8% whereas the δN15 range of animal waste nitrate was +10 to +20%- (Atmospheric nitrogen was used as a standard for mass spectrometric analysis. Experimental error for sample preparation and isotopic analysis was ±1 %.) More than 66 percent of the ground-water nitrates analyzed were in the δN15 range of natural soil nitrates.Dryland farming since 1900 has caused the oxidation of the organic nitrogen in the soil to nitrate. Minimal fertilizer has been used because of the lack of suitable water for irrigation. During the period 1900-1950, nitrate was leached below the root zone but not to the water table. Extensive terracing after the drought in the early 1950's has raised the water table approximately 6 meters and has leached the nitrate into the ground water. Tritium dates indicate that the ground water is less than 20 years old.

Notes: Salt-water migration into relatively shallow rocks in the western half of West Virginia is already rather far advanced. Because of the wide distribution of salty ground water and connate brine at various depths, it is difficult to determine how much of the contamination is natural and how much is the result of subsurface industrial activities. Although some local salt-water problems are the result of oil and gas operations, much of the regional near-surface salt water is a natural condition unrelated to deep drilling or other industrial activities.Ground water is usually more abundant from consolidated aquifers beneath the valleys than from beneath the ridges. However, the presence of shallow salt water beneath the valleys imposes limitations on the availability of fresh water from a single well. Because most well fields must be located along the populated valleys, the problem of interception of salt water is the most important factor limiting development of consolidated bedrock aquifers. By utilizing the history of development and operation of well fields, an estimate of the availability of fresh water can be made, and test drilling and new well field construction guided accordingly.During 1971 to 1974, more than a dozen small communities in Logan and Boone Counties started development of public-water supplies from wells. Existing water-supply problems in these areas are being solved by using the cumulative experience of other communities in the area. Ground water is currently being developed in valley areas of Logan County such as Man to Lorado, Essie to Big Creek, and Huff Creek to Mallory. Adequate well fields have recently been successfully constructed just above shallow salt water in bedrock aquifers at Hattie in Calhoun County, near Madison in Boone County, near Southside in Mason County, and at Prichard in Wayne County. In all of these areas of successful construction, the essential information for initial test drilling was obtained by detailed hydrogeologic work at the prospective sites. Most important was the determination of the maximum depth of fresh water, well spacing and pumping rates.

Notes: The solution of two-dimensional ground-water flow in soils of low hydraulic conductivity under the influence of both electrokinetic and hydrodynamic forces is found using the finite element method. The example investigated deals with a confined aquifer in which there is a recharging as well as a discharging well present. The results demonstrate the effect of the application of the electro-osmosis phenomenon. The formulation is general and permits the analysis of not only arbitrary shaped boundaries but also different electrode configurations.

Notes: A specific hydrologic model of a stream-alluvial aquifer system was developed for the purpose of designing rules and regulations which maximize the beneficial uses of the waters of a State within the law. The model is particularly suited when decisions on pumping rates are to be reviewed on a frequent regular basis. The procedure is illustrated on a simplified case for which the river loss influence coefficients can be obtained by a combination of analytic derivations and algebraic manipulations.

Notes: Delineation of major depositional systems and their component facies within the Lower Cretaceous Hosston and Hensel Sandstones provides a model for predicting the distribution and chemical composition of water in the aquifer. Two major depositional trends occur in the Hosston Formation: (1) a dip-oriented meanderbelt fluvial system which supplied sediment to (2) a strike-oriented, high-destructive, wave-dominated delta system in the east. The Hensel deposits prograded eastward across the featureless upper surface of the Pearsall Formation, forming two depositional systems similar to those of the Hosston. The meanderbelt sandstone facies of the fluvial systems and the coastal barrier facies of the delta systems are capable of supplying greater amounts of ground water than the floodbasin, lagoon-marsh-embayment, or prodelta/shelf facies. Ground water is dominantly of the calcium-magnesium bicarbonate type in the fluvial systems but changes downdip to sodium sulfate and sodium bicarbonate types in the delta systems. The change in chemical equilibrium probably occurs as dolomite-rich waters from the fluvial facies percolate downdip and dissolve anhydrite or oxidize pyrite in lagoonal facies within the delta system, and calcium may be exchanged for sodium on the marine clays.

Notes: From 1965 till his death on January 30, 1970, Professor C. E. Jacob was chairman of Ground-Water Hydrology at New Mexico Institute of Mining and Technology. During the last three decades, ground-water studies have advanced considerably due to his efforts, original achievements, and philosophies. He is therefore considered by many as one of the founders of modern ground-water hydrology. In this study, taken from unpublished reports and notes, Jacob projects the decline of the water table in the Ogallala aquifer of the Southern High Plains of New Mexico and Texas. After developing approximate analytical solutions for steady and unsteady flow as a function of flow depth, slope, water-table configuration, and recharge, numerical results are obtained by digital computation. Representative values of porosity and hydraulic conductivity, required for this purpose, were obtained from an analysis of well data. The author concludes that the hypothetical time required for draining the aquifer, without pumping and without recharge, is from 5,000 to 8,000 years. At pumping rates prevailing during the decade 1951-1960, with natural recharge and discharge operating, the aquifer will be depleted in less than 100 years. Starting with complete exhaustion, the aquifer would recover to within 2 percent of its initial (1938) storage in 5,600 to 5,700 years. If pumpage had ceased at the end of 1958, recovery to within 2 percent of initial storage would probably not exceed 1,500 years. These estimates assume that no local or temporary climatic fluctuations of the water table take place during the time spans considered.

Notes: Hexavalent chromium (Cr+6) of natural origin has been found in the ground water in Paradise Valley, Maricopa County, Arizona. The concentrations exceed 0.05 milligrams per liter, the U.S. Public Health Service's upper limit for Cr+6.Paradise Valley is a northwest-trending, down-faulted basin of about 225 square miles that is located in the semi-arid Basin and Range physiographic province. The accumulation of fine-grained sediments (in part gypsiferous) near the center of the basin indicates that the material was deposited in a playa-type sedimentary environment.The Cr+6 is present in the ground water in a 75-square mile area and forms an elongate northwest-trending pattern in the southern part of the basin. The largest Cr+6 concentrations are located in the approximate center of this pattern and decrease toward the margins. The Cr +6 distribution in the ground water corresponds to the location of the fine-grained part of the alluvial deposits; the highest Cr +6 concentrations are associated with the finest-grained sediments. Evidence indicates that the Cr+6 is fairly evenly distributed vertically in the ground water, at least throughout the finer-grained part of the aquifer system.Thermodynamic calculations and Eh and pH measurements of the ground water indicate that the water containing Cr +6 is oxidizing and alkaline enough to account for the observed concentrations. An alkaline environment, largely a result of primary silicate hydrolysis in the fine-grained sediments, allows chemical oxidation of the trivalent chromium to the soluble Cr+6

Notes: The bacterial flora of three unpolluted saline aquifers were examined. Aerobic, anaerobic, and facultative microorganisms were isolated and classified to genus. The organisms isolated were those commonly found in surface water and soil. Methanogenic bacteria were present in all aquifers.

Notes: Water zoning is not new in arid areas. Many States have laws limiting pumping. However, most of the existing ordinances do not achieve their stated purpose. Many enforce conservation of scarce resources for benefit of future users. Some purport to ensure a continuous water supply to the rights holders. Existing ordinances that limit pumping to the so-called safe yield do not take costs or recoverable benefits into consideration, and the period of use is not stipulated. Therefore, where pumping is regulated under such ordinances, the basins cannot be managed to obtain maximum benefits to present users of the available supply. Two types of ordinances are discussed: general-purpose and management-plan ordinances, which are designed to make possible the achievement of specific objectives. Examples are given of how the latter can be designed to: limit stream depletion and protect existing rights; disperse pumping to increase economic return; force conjunctive use of all land, mineral, and water resources; and establish production quotas to insure optimum economic return to all users during a predetermined period.

Notes: The Pliocene Ogallala Formation and the Quaternary Sand Hills Formation cover an extensive area in the north-central prairie states. The area studied in this investigation includes only that portion between the Little White River, South Dakota, and the Niobrara River, Nebraska, where the saturated thickness is about 100 feet and a five-day aquifer test showed that the coefficient of permeability is 439 gpd/ft2. The water has a total dissolved solids content of only 90 ppm. An average of 18 inches of precipitation falls on this arid country annually, and the average annual recharge to these permeable deposits is calculated at 2 to 3 inches.Little ground-water development has occurred in the area to date, but the aquifer has considerable potential. The aquifer is exceptionally permeable, close to the surface and easy to drill, and has exceptionally good recharge and good quality water. Data on recharge rates and theoretical distance-drawdown curves support the conclusion that irrigation of more than 1 quarter-section for every 2 sections of land would cause a depletion of the aquifer.

Notes: Many geohydrologists believe that the step-drawdown test is useful in determining many important characteristics of a well, whereas others altogether question its utility. In addition to this controversy, its application is hindered because the graphical analysis of data is unwieldy. A computer code is presented for step-drawdown test analysis which is efficient and simple to use; moreover, it is an example of how optimization can be used in a practical way. A listing of the FORTRAN code is included along with some example calculations.

Notes: The potential for artificial ground-water recharge through shallow shafts is being conducted at the Leaky Acres Recharge Project in Fresno, California. The research is directed toward developing methods for constructing and placing filter-pack materials and procedures for periodically cleaning filter materials to regenerate initial intake rates. This report presents preliminary results of two differently constructed shallow shafts.Over a period of 94 days, 50.8 X 103 cu m (13.4 million gals) of screened canal water was recharged. Redevelopment with a submersible pump regenerated one shaft to 109 percent of its original intake rate. Piezometric observations indicated that most of the clogging occurred within the filter-pack material.

Notes: Basin artificial ground-water recharge rate at the Leaky Acres Recharge Project in Fresno, California was evaluated by Fourier analysis of temperature variations of air, basin water and ground water. The weekly mean basin-water temperature correlated well (r = 0.982) with weekly mean air temperature. Weekly mean temperature data of the air, basin water, and recharged ground water showed that the first harmonic curve was satisfactory for determining the times of minimum and maximum temperature when convective transfer of heat was considered.The lag time between maximum basin-water temperature and maximum ground-water temperature at a 16 m depth (52.5 ft), showed water moved at a thermal tracer velocity of 20.8 cm/day (0.68 ft/day). The corresponding infiltration rate measured by the falling-head method in study area basins was 18.5 cm/day (0.61 ft/day). This and other reported studies indicate that under suitable conditions with simple field instrumentation ground-water thermometry can be used to estimate the rate and direction of recharged water movement.

Notes: Periodically, Alum Creek at the Westerville water treatment plant contains excessive concentrations of chloride, producing a salty taste. The chloride is not removed during the water treatment process. Uncontaminated surface water and ground water throughout Alum Creek basin contain less than 25 mg/l of chloride. Larger concentrations are related to man's activity in the basin, particularly oil production.The chloride content in samples of contaminated surface water ranged from 26 to nearly 28,000 mg/l while samples from oil-field brine pits ranged between 3,000 and 57,000 mg/l.Even a brief examination of the data indicates that most of the chloride contamination in Alum Creek is due to (1) the discharge of oil-field brines directly into the mainstem or its tributaries in the upper reaches of the basin or (2) to the discharge of contaminated ground water into streams. In many areas, the highly mineralized ground water that is now seeping into the streams may have been contaminated a decade ago.

Notes: This study is part of an interdisciplinary analysis of the economic evaluation of the water resources of the Rio Grande region of New Mexico. It was elemental in obtaining dynamic water availabilities in time and space.The relationship of dynamic ground-water availability and aquifer behavior under projected stresses was modeled by a ground-water system simulator based on a mass balance of the hydrologic basin. Conditions from extreme dry to extreme wet were modeled, combined with a range of different water demands. A vast amount of information was thus obtained in the form of aquifer responses for different conditions. An analogous relationship was constructed from these data by stepwise multiple regression analysis and was of the following formλd = f (dn, L)where λd = change in water-table elevation for the time period considered, dn= water-table elevation at the end of the previous time period, and L = a lump factor combining surface-water inflow and outflow, precipitation, and beneficial and nonbeneficial water uses.Other results readily obtainable from the simulation runs are river accretion or depletion curves as a function of time. These curves show the diversion effects of groundwater pumping upon the river.

Notes: The upconing of saline water in response to pumping from an overlying layer of fresh water is investigated by numerical integration of the governing differential equation. The transition zone between the fresh and saline water is idealized as an abrupt interface. Full consideration of the nonlinear boundary conditions on the water table and interface surfaces is included for steady flow toward partially penetrating pumping wells in both isotropic and anisotropic aquifers. There exists an optimum well penetration into the fresh-water layer which permits maximum discharge without salt-water entrainment. The optimum penetration increases as the vertical permeability is reduced relative to the horizontal permeability. The maximum well discharge obtainable without salt-water entrainment is greater for aquifers with a reduced vertical permeability than for isotropic aquifers, a result that contrasts with previously published conclusions. Previous analyses which linearize the boundary condition on the interface overestimate the critical discharge.

Notes: The City of Champaign, Illinois, began controlled landfilling of its municipal refuse as early as 1904. Since that time, the disposal of solid wastes by sanitary landfilling has developed from a desirable concept, seldom utilized, to a science, carefully implemented and regulated. Illinois is typical of an area of humid continental climate whose citizens and industries depend heavily on ground-water supplies developed from both nearsurface and bedrock aquifers. Seasonal water-table fluctuations may be large in some parts of the State, but ground water is seldom far below the surface. Special problems are often encountered in design of protective systems and development of monitoring programs for solid waste disposal sites in this area to safeguard valuable ground-water resources. Critical decisions, often involving considerable time and expense to the disposal site operator, must frequently be made by regulatory agencies responsible for licensing and surveillance of solid waste disposal sites in such a hydrogeologic environment. These problems have been compounded by the fact that State regulatory agencies have only recently realized the importance of hiring hydrogeologists, soil scientists, chemists and engineers to effectively implement and enforce their environmental control programs relating to solid waste disposal.This paper summarizes the experience in Illinois of development of a rational program for protection of the State's ground and surface water from the indiscriminant disposal of solid wastes. Classes of solid waste sites recognized in the State and their position in terms of the hydro-geologic environment are presented. Means of controlling landfill leachate, either by natural renovation in subsurface materials or by engineered collection and treatment are discussed. Examples are presented which illustrate the in-field implementation of protective systems and monitoring devices for ground water in Illinois, which should be generally applicable to other areas of the country of similar geology and climate.

Notes: Iron in ground water is often present both in solution and as suspended ferric oxyhydroxides. In most instances amounts of dissolved iron in natural waters are limited by the solubility of the ferric oxyhydroxides, whether suspended or present as part of aquifer materials. Oxyhydroxide solubilities, which range widely in natural waters, may be described by pQ =-log [Fe3+] [OH-]3, where [Fe3+] [OH-]3 is the product of ion activities in the water. pQ. values calculated from Fe(II), Eh, and pH measurements in several types of high iron ground and surface waters (Fe(II) = 0.02 to 1460 ppm) indicate that most of the waters are in equilibrium with ferric oxyhydroxides which range from amorphous material to crystalline goethite (pQ values at 25°C from about 37 to 44, respectively). Stabilities generally increase (higher pQ's) in a given water with time. In general, the lower the dissolved iron, the more soluble is the oxyhydroxide precipitated and the slower its increase in stability. This was observed both in coastal-plain ground waters (pQ= 36.6 - 42.7), and in laboratory aged solutions. The faster the oxidation and hydrolysis rate of dissolved Fe(II), the lower the pQ, as shown by the reaction of mineralized spring waters with varying amounts of surface waters (pQ= 37.2 - 41.5). Where saturation of water with siderite occurs, the siderite is in equilibrium with amorphous ferric oxyhydroxides (pQ= 36.9 - 37.4 for calcium, magnesium bicarbonate ground waters). pQ values 〉 44.2, in a flooded coal mines for example, indicate that another iron mineral such as pyrite may control dissolved iron level.

Notes: The spectacular occurrence of a sinkhole near the Gulf Coast of Florida engulfed a well drilling rig, a water truck, and a load of PVC pipe on a trailer, all within less than 10 minutes. The 150-foot diameter sinkhole, which was initially dry and extended to a depth of 59 feet below mean sea level, developed suddenly on September 19, 1974. This occurred during the drilling of a 6-inch well in Hernando County, about 5 miles inland from the Gulf of Mexico at a land surface elevation of 11 feet above mean sea level. The sinkhole which displaced 6500 cubic yards began to develop when the drill bit entered a cavity at a depth of 202 feet. Numerous satellite sinks ranging up to 20 feet in diameter occurred simultaneously with the develop- ment of the parent sink. Within 24 hours, ground-water discharge into the parent sink from the shallow, unconfined and unconsolidated aquifer had filled the sink to an elevation of 8 feet above mean sea level. The total esti- mated replacement cost of the equipment lost in the sinkhole is $120,000.

Notes: This paper is designed to provide technical data supporting the concepts presented in the guest editorial of William H. Walker, Chairman, NWWA Technical Division, as presented in Ground Water, Vol. 12, No. 5, September-October 1974. The guest editorial was entitled, “Our Buried Resource, May It Rest in Peace.”The Federal Water Pollution Control Act Amendment of 1972 (Public Law 92-500) will necessitate a significant expansion of landfill facilities and operations throughout the United States by 1977. The nature of the additional materials to be introduced into landfills as a consequence of this law will require additional precautionary measures if pollution of ground water by lixiviation is to be precluded. Recent studies of the waste production characteristics of the aluminum industry contain documentary evidence for this conclusion. The aluminum industry is representative of conditions in the iron and steel industry, the ferroalloy industry, and the copper, lead and zinc industries (see Williams, 1975). Mr. Walker discussed only the fossil fuel power production industry.Public Law 92-500 specifies July 1, 1977, as the deadline date for application of the “Best Control Technology Currently Available” to point source waste water discharges from essentially all U.S. industries. In many cases these industries convert airborne wastes to waterborne wastes by utilization of wet or semi-wet air pollution control techniques. In the majority of these cases the best control technology currently available consists of converting these waterborne wastes to solid wastes by some combination of pH control, precipitation and coagulation. Where recycle is impossible, these solid wastes must be discarded in sanitary landfills or similar solid waste disposal sites.In primary aluminum plants wherein dry fume scrubbing is not employed, effluents from wet scrubbers used for air pollution control constitute the major waste water. The major contaminants in this water are soluble fluorides, suspended solids and organic constituents. These wastes (initially airborne) result from the production of fluoride compounds during the electrolytic process and the consumption of coke and petroleum products as anode materials. Fluoride content ranges from 10 to 30 mg/l in various waste streams. Bleed streams from wet scrubbers must be neutralized for precipitation of fluoride as calcium fluoride or sodium aluminate can be added to precipitate fluoride as cryolite. Complete recycle of scrubber effluent is precluded by sulfate buildup. The precipitated fluoride compounds are contaminated by other compounds and frequently are too impure for recycle; thus they must be landfilled. Because many of these compounds are subject to lixiviation under acid conditions extreme care will be required if pollution of ground water is to be precluded. A similar situation exists in the secondary aluminum recovery industry.The primary and secondary aluminum recovery industries constitute examples of industries wherein compliance with Public Law 92-500 should include preparation and planning for additional landfill sites if ground-water pollution is to be precluded.

Notes: The purpose of this paper is to present a method of assessing ground-water interference effects of multiple wells upon any given well in an aquifer. The method specifically relates to depleted aquifers and attempts to assign the responsibility for the depletion effects to all users on a reliable basis. This basis entails the fundamental relationships between the pertinent variables and is not a simple percentage of water usage rates. The method takes into account both flow magnitude and radial distances from all users to the given depleted well. Large flows at longer distances, in general, affect a given well less than smaller flows at closer distances.The methodology applied in this paper was developed as a result of a legal suit where relative responsibility among several users for depletion effects had to be assigned. The method will assign the effects, or deprivation contribution, of all water users on any given well in an aquifer common to all the wells. The limitations of the method are also discussed.

Notes: Ground water of Shiraz alluvial basin in Zagros range (south Iran) shows three principal anion types, namely chloride, sulfate and bicarbonate. Intermediate types between these groups are also present, which seem to represent modifications in ground water due to diagenesis.Possible chemical origin of the ground water is mainly due to two major processes either acting individually or collectively, i.e. solution of minerals of the geological formation and mixing of ground water accompanied by the precipitation of some constituents such as calcium.

Notes: Geomorphic and hydrogeologic studies have shown that the material, topographic, ground-water, and surface-water characteristics of a particular landscape position are all related. Because topography is related to the local material and surface-water characteristics and because the ground-water regimen is related to the local materials and topography, an analysis of the topography should allow the prediction of the material, ground-water, and surface-water characteristics of a disposal site within the local area. Topographic consideration of potential solid waste disposal sites thus provides insight about the physical characteristics of the site and shape of the resulting contamination enclave.Seven possible topographic positions for disposal sites are floodplain, valley terrace, valley side, upland crest, upland ravine, upland valley and upland flat interfluve. Upland sites are characterized by the outward flow of both ground water and surface water, whereas valley sites are characterized by the through flow of both ground and surface water. At the present time, upland sites are considered preferable over valley sites because of the greater likelihood of the refuse remaining dry. An analysis of ground-water flow patterns indicates that the greatest potential for extensive ground-water contamination exists for upland sites, which are in ground-water recharge areas; and the least potential for extensive ground-water contamination exists for properly placed valley sites, which are in ground-water discharge areas.

Notes: Formulation and solution of one-dimensional analytical and computational models, linear as well as nonlinear, pertaining to a typical ground-water recharge pattern are presented. The objective of this investigation is to direct attention toward an evaluation and correlation of the various theoretical models based on the Dupuit-Forchheimer (D-F) approximations for the unsteady hydrodynamic behavior of the proposed recharge system under saturated flow conditions. Comparisons with the pertinent experimental data, presented in the form of dimensionless graphs, indicate that the linear D-F theory is valid for relatively small water-table rises but for large rises it predicts substantially greater rises than actually occur, particularly beneath and in the vicinity of the recharge basin. The range of validity is considerably improved between theory and experiments for relatively large rises using the nonlinear theory.

Notes: A mathematical expression was developed which would approximate the steady position and shape of a sharp, upconed interface between fresh and salt water in an aquifer when the fresh water only is being pumped from a well. The computation of the interface shape was based on an empirically derived modification of Muskat's approximation for the height of the cone beneath a well. Differing depths of well penetrations and their effect on the upconed interface were investigated with the approximation. The computed interfaces were compared with corresponding interfaces determined experimentally in a Hele-Shaw model. Close agreements could be achieved for interfaces which penetrated as much as 50% of the distance between the bottom of the well and the initial interface position. Changing the length of the producing interval of the well while keeping its pumping rate constant did not have a significant influence on the shape or position of the upconed interface. Even though the shape and position of the upconed interface could be approximated, a refinement of the analytical methods used in deriving the approximation for the interface may be necessary before it can be applied reliably.

Notes: The fluoride content of ground water in India varies considerably. Among factors which control the concentration of fluoride are the climate of the area and the presence of the accessory minerals, fluorite and (or) apatite in the rock mineral assemblage through which ground water is circulating. Regional and tectonic factors also play some part in affecting the fluoride concentration of ground waters. In general, there is a negative correlation between calcium and fluoride concentrations and a positive correlation between fluoride and bicarbonate concentration in ground waters with high fluoride content. Thermodynamic calculations show that some of these high fluoride ground waters are supersaturated with respect to fluorite.In water sources from Rajasthan, high fluoride concentrations are generally accompanied by high nitrate concentrations. A solution-evaporation-base exchange hypothesis is put forward to explain the genesis of these ground waters.In some parts of India, the fluoride content of ground waters is below 0.5 mg/1, indicating that fluoridation of water supplies may be desirable in these places.

Notes: Faulty disposal of oil field brine through an “evaporation” pit and later through a faulty disposal well resulted in the contamination of one square mile of an alluvial aquifer in southwestern Arkansas. The physical parameters of the contamination are defined, and some of the chemical changes that occur as the brine moves through the aquifer are explained.In addition, alternate methods of aquifer rehabilitation are explored, and the costs of rehabilitation are compared with potential benefits. It is concluded that rehabilitation is not now economically justified.

Notes: An important part of every investigation of ground-water pollution is to locate and define the extent of the contaminated body of ground water. The usual method for accomplishing this is to install and sample numerous test wells, a costly and time-consuming procedure. A much faster and less costly method, which has proven to give accurate results, is the earth resistivity survey. Because earth resistivity is inversely proportional to ground-water conductivity, the location of ground water that has been contaminated by a relatively high concentration of conductive industrial wastes, for example, may be quickly and accurately traced.In order for the resistivity method to give useful results, resistivity contrasts must exist in the subsurface. For example, if the contaminant does not have a significantly greater conductivity than the natural ground water, or if the ground water is naturally highly conductive itself, a large enough resistivity contrast may not exist, and the method may not work. In addition, if depth to water is too great, the thickness of the unsaturated sediments can mask any contrasts between contaminated and natural ground water. The geologic environment must be relatively uniform so that the resistivity values and profiles can be compared with one another. At most industrial plant sites and landfills, these conditions are met. That is, the area of investigation is usually limited to a few hundred acres, where the geology and depth to water tend to be uniform.Four case histories of industrial and landfill sites are discussed in this paper. The areas underlain by the contaminated ground-water bodies ranged from 25 to 100 acres. The depths to the contaminated water were relatively shallow, ranging from 5 to about 60 feet below land surface. In three of the cases, the results of the earth resistivity studies, which were verified by installing test wells in and around the area being investigated, proved to be remarkably accurate. In the fourth study, the conditions mentioned were not met, and the survey was unsuccessful.

Notes: Woodward-Clyde Consultants was retained to investigate a ground-water contamination problem caused by disposal of chromium-laden process water into an unlined lagoon in the Coastal Plain sediments of southern New Jersey. During the course of the investigation, a technique for sampling of formation water at specific horizons during drilling was developed. This technique consists of the following procedure: (1) drilling a borehole to the base of a sampling horizon; (2) lowering a wire-wound well screen and riser pipe to the bottom of the borehole and gravel-packing the screen; (3) pumping the borehole well until the discharge is clear of drilling fluid; and (4) pumping at least 100 gallons of formation water before collecting the sample and performing field water quality tests.Analysis of water samples withdrawn from a cluster of five wells, drilled to and screened at specific depths of 20 to 100 feet, verified that the special drilling and sampling technique developed was a valid method to obtain representative, in-situ water samples from specific horizons. This sampling procedure was then used to substantiate surface earth-resistivity survey data and provide important information on the vertical distribution of the contaminant within the aquifer. The delineation of the contaminant within the aquifer was an important part of Woodward-Clyde Consultants'responsibility to evaluate the extent and magnitude of ground-water contamination at the plant site and design an economically and technically feasible system for the removal and treatment of the contaminated ground water and eventual recovery of the chromium.

Notes: Studies at three solid-waste disposal sites in the Anchorage area suggest that differences in local geohydrologic conditions influence ground-water quality. A leachate was detected in ground water within and beneath two sites where the water table is very near land surface and refuse is deposited either at or below the water table in some parts of the filled areas. No leachate was detected in ground water beneath a third site where waste disposal is well above the local water table.

Notes: In cooperation with the city of Indianapolis, the U.S. Geological Survey undertook a study to determine the nature and extent of water pollution resulting from the operation of seven landfills in or near the city. To accomplish this, 10 to 36 observation wells, ranging from 14 to 170 feet (4 to 52 metres) deep, were installed in and around each landfill. The wells were installed variously by auger, rotary, and air-rotary methods; the mud for the rotary drilling was natural mud, bentonite and(or) an organic polymer. The wells were constructed of 2-inch (5-centimetre) PVC casing, and ended either in slotted casing or PVC “wire-wrapped” screen. After the wells were completed and developed, water samples were collected from selected wells for detailed chemical analysis. This type of analysis will be repeated yearly on selected wells. Every month the water levels are measured and field determination of four chemical and physical water parameters are made. Water samples have been collected using a bailer, a centrifugal pump, and a gas-driven pump.Based on the experiences so far, the following are considerations in planning future studies:〈list xml:id="l1" style="custom"〉1Keep the objectives of the study well in mind in planning the methods to be used and the financing.2Black iron pipe is suitable well casing except when careful analyses are needed for research projects, for sampling concentrated leachate, or where rapid corrosion can be expected.3Use of 4-inch (10-centimetre) casing may provide more options than 2-inch (5-centimetre) casing as to method of collecting water samples, and may be easier to install and develop.4A power auger is preferable for drilling and installing small-diameter wells in refuse.5A drilling mud made with an organic polymer is effective, particularly if 2-inch (5-centimetre) casing is used, but provides a medium for bacterial growth.6When the water level is too deep for a centrifugal pump to function in a 2-inch (5-centimetre) well, a bailer is more efficient and fairly contaminant-free.7Once good control on water quality is obtained, field determination of selected parameters is sufficient to follow movement of a leachate plume.

Notes: The Lake George Village sewage treatment plant has been discharging trickling filter effluent onto natural delta sand beds for a period of 35 years. The applied sewage apparently appears near the banks of West Brook approximately 600 m (2000 ft) from the lower sand beds. Wells have been placed between the recharge beds and the appearance of the seepage at West Brook. The quality of the water in the wells has been evaluated over the period of slightly over one year.The ground water appears to be aerobic at all times indicating that the oxygen demand of the applied effluent has been adequately reduced before it reaches the ground water. This should afford adequate and proper tertiary treatment for the applied effluent.The phosphorus concentration was significantly reduced at the first well downstream (ground water) approximately 150 m (500 ft) from the sand beds. The phosphorus in well 2 approximately 600 m (2000 ft) from the lower sand beds reached a high value of 150 μg/l during the late fall but was less than 100 μg/l during the rest of the year.Some of the nitrogen in the applied effluent was apparently oxidized to nitrate which was very little removed by the sand system. The highest nitrate concentration found was 14 mg N/l in well 3C during the Spring, whereas well 3A had almost consistently the lowest concentration of nitrate.

Notes: The theoretical shape of a zone of contaminated ground water (henceforth called an enclave) can be predicted from a knowledge of the three-dimensional, ground-water flow pattern. The reasoning in LeGrand (1965) and Sendlein and Palmquist (1973) suggests that the horizontal shape of the enclave is a flame-like plume extending from the source, parallel to the ground-water flow lines, in a downflow direction. According to LeGrand, the ultimate size of the enclave will depend upon the relative rates of decay, diffusion, dilution and absorption of the contaminants. Similar reasoning suggests that, in vertical section, the boundaries of the enclave will follow the ground-water flow lines between contamination source and ground-water discharge site. This reasoning suggests that the three-dimensional shape of an enclave is that of a tongue-like lobe, the length, width and depth of which increases with increasing distance from and increasing height above the discharge site.In Iowa, the hydrology of refuse sites emplaced in alluvium has been analyzed to determine the size and shape of the associated enclaves. The refuse sites range in size from 13 to 117 acres (5.25 to 47.3 hectares), in age from 9 to 40 years, and in topographic position from floodplain adjacent to river to terrace. The ground-water quality and water-table elevations were determined from multiple nests of piezometers (from depths of 15 to 45 feet) (4.7 to 13.6 meters) around the refuse sites. The surficial geology of the sites was established from both borehole and geophysical data.The Iowa data suggests that the enclave in alluvium is plume-shaped with the long axis parallel to the ground-water flow lines and extending from the refuse site to the nearest stream. The SO4 enclave at the Ames site, for example, is over 7000 feet (2121 meters) long, 4500 feet (1362 meters) wide and extends to a maximum depth of 60 feet (18.2 meters). The highest SO4 concentrations are along the axis of the enclave at a depth of 30 feet (9.09 meters). The concentrations decrease with distance along the axis, laterally away from the axis and vertically away from the axis, such that the enclave is entirely surrounded by uncontaminated ground water except at the source. Analysis of the variation in water quality data with time indicates that most of the enclaves are not increasing in size but have achieved their maximum size and are in a steady-state equilibrium condition.The Iowa studies indicate that the size and shape of the contamination enclave resulting from refuse disposal sites can be predicted from the initial geohydrologic conditions and that it may become possible in the near future to estimate the concentrations within the enclave at any point in time and space. These possibilities open the way toward a strategy of minimizing potential contamination of aquifers through selective refuse site placement on the floodplain. The Iowa data indicates that floodplain sites may be desirable for disposal sites because of the predictability of enclave shape within alluvium, the tendency for floodplains to be ground-water discharge sites and the low concentrations of the leachate produced in a high ground-water flow environment.The results of this study strongly indicate that any monitoring system around a refuse disposal site be judiciously placed. Not only must the location of the wells be considered but also the depth of wells. To monitor maximum leachate concentrations, wells must be located in a downflow direction and along the axis of the enclave. Likewise, wells which are too shallow or too deep will miss the core of an enclave and yield leachate samples with low concentrations. It thus becomes necessary to estimate the size and shape of the enclave prior to establishment of a monitoring system.

Notes: More than 10 billion gallons (38 × 106 m3) of acid industrial liquid waste has been injected in about 11 years under high pressure into a saline-water-filled part of a limestone aquifer of low transmissivity between 1,400 and 1,700 feet (430 and 520 m) below land surface near Pensacola, Florida. A similar waste disposal system is planned for the same zone at a site about 8.5 miles (13.7 km) to the east. The injection zone is the lower limestone of the Floridan aquifer. The lower limestone is overlain by a confining layer of plastic clay about 220 feet (67 m) thick at the active injection site and underlain by another confining layer of shale and clay. The upper confining layer is overlain by the upper limestone of the Floridan aquifer.The active injection system consists of two injection wells about a quarter of a mile (0.4 km) apart and three monitor wells. Two of the monitor wells (deep monitors) are used to observe hydraulic and geochemical effects of waste injection in the injection zone at locations about 1.5 miles (2.4 km) south and 1.9 miles (3.1 km) north of the center of the injection site. The third well (shallow monitor), used to observe any effects in the upper limestone, is about 100 feet (30 m) from one of the injection wells. Since 1972 the injection zone has also been monitored at a test well at the planned new injection site. Three more monitor wells in the injection zone were activated in early 1974 at sites 17 miles (27 km) northeast, 22 miles (35 km) east and 33 miles (53 km) northeast of the injection site. The six deep monitors provide a system for evaluating the regional effects of injecting wastes. No change in pressure or water quality due to injection was, by mid-1974, evident in the upper limestone at the injection site, but static pressures in the lower limestone at the site had increased 8 fold since injection began in 1963. Chemical analyses indicated probable arrival of the diluted waste at the south monitor well in 1973. By mid-1974 waste evidently had not reached the north monitor well.Calculations indicate that by mid-1974 pressure effects from waste injection extended radially more than 40 miles (64 km) from the injection site. By mid-1974 pressure effects of injection were evident from water-level measurements made at the five deep monitor wells nearest the active injection site. No effects were recognized at the well 33 miles (53 km) away. Less than 20 miles (32 km) northeast of the active injection site, the lower limestone contains fresh water. Changes in the pressure regime due to injection indicate a tendency for northeastward movement of the fresh-water/salt-water interface in the lower limestone.

Notes: Door County, a recreational and fruit-growing area bordering Lake Michigan in northeastern Wisconsin, has had a long history of ground-water contamination from surface and near-surface sources. Contamination is most severe in late summer when the influx of tourists and fruit-canning operations create additional wastes.Thin soil cover and well-fractured dolomitic bedrock give easy entry to ground-water contaminants throughout large parts of Door County. Many contaminants enter the dolomite by surface or near-surface seepage. There is little attenuation of contamination concentrations in the well-jointed dolomite, and contaminants may travel long distances underground in a relatively short time. The major source of ground-water contamination is bacterial, from individual waste-disposal systems, agricultural, industrial, and municipal sources. Contamination is in zones that originate from point sources and move in the direction of ground-water flow, either naturally or as induced by pumping wells. The contaminated areas include only a small percentage of the total ground-water system and are separated by large areas of ground water free of contamination. Tests based on indicator bacteria suggest that the periods of highest contamination potential occur during or immediately following rapid ground-water recharge periods. Increasing the depth of casing and pressure grouting the casing into firm bedrock are two well-construction procedures that reduce the contamination potential in wells.

Notes: Timber production and wood products industries in the Mid-Willamette Valley of Oregon annually dispose of about 547,000 tons (500,000 tonnes) of wood and bark wastes. Land storage or disposal of these wastes can result in the generation of significant volumes of leachate.Wood waste leachates are commonly characterized by lignin-tannin (measured as tannic acid), oxygen demanding materials, color, and odor. In this study, lignin-tannin concentrations in the ground water ranged as high as 7.5 mg/l; iron and manganese were also shown to increase markedly relative to natural background concentrations, ranging as high as 13 mg/l and 106 mg/l, respectively.In August 1972 the area affected by the contaminated ground water covered about 4 acres (1.6 hectares) and extended nearly 1,000 feet (330 meters) downgradient from the disposal site. By late January 1973 the plume had migrated laterally to affect an area of about 15 acres (6 hectares) while extending over 1,500 feet (460 meters) downgradient. The lateral migration is attributed to a seasonal change in the local flow system. At least eleven existing domestic water-supply wells have been rendered nonpotable by this pollution.

Notes: ERTS imagery offers the first opportunity to apply moderately high-resolution satellite data to the nationwide study of water resources. This imagery is both a tool and a form of basic data. Like other tools and basic data, it should be considered for use in ground-water investigations. The main advantage of its use will be to reduce the need for field work. In addition, however, broad regional features may be seen easily on ERTS imagery, whereas they would be difficult or impossible to see on the ground or on low-altitude aerial photographs.Some present and potential uses of ERTS imagery are to locate new aquifers, to study aquifer recharge and discharge, to estimate ground-water pumpage for irrigation, to predict the location and type of aquifer management problems, and to locate and monitor strip mines which commonly are sources for acid mine drainage. In many cases, boundaries which are gradational on the ground appear to be sharp on ERTS imagery. Initial results indicate that the accuracy of maps produced from ERTS imagery is completely adequate for some purposes.

Notes: In 1964 a waste disposal firm began dumping neutralized spent pickling liquors into an abandoned strip mine in eastern Ohio. In 1970 the disposal pit was enlarged and shortly thereafter significant water pollution problems began to occur. Highly mineralized fluids began to leak from the disposal pit into the surrounding spoil material and eventually into streams and ponds. These solutions are characterized by a low pH and excessive concentrations of dissolved solids, hardness, sulfate, chloride, nitrate, iron, fluoride, aluminum, chromium, nickel, and zinc.In addition to the contamination by steel mill wastes, acid-mine drainage from surrounding areas degrades both surface and ground water. Acid-mine drainage is characterized by a low pH, and high concentrations of dissolved solids, hardness, sulfate, and iron.Geohydrologic and geochemical data clearly illustrate that abandoned strip mines should not be used for the storage of toxic liquid or semiliquid materials.

Notes: Most municipal waste treatment systems receive, treat, and eventually discard to some segment of the environment storm runoff and liquid wastes from all industrial, commercial, and domestic areas and establishments in the community. At any given time these wastes may contain viruses, antibiotics, hormones, nutrients, weedkillers, fungicides, pesticides, trace metals, and an almost countless number of toxic chemical compounds. Present treatment by the old, ineffectual sewage treatment methods and facilities still employed generally does not remove nor reduce to a harmless state all of the hazardous materials contained in the waste streams entering the plant. Some are more concentrated when they leave the plant in effluent and sludge than they were upon entry.Existing pollution protection laws prohibit surface-water dilution of these effluents and sludges. Drying, burning, or distilling them is very costly, causes air pollution, and produces potentially hazardous chemical residues which still must be disposed of in some nonpolluting fashion. There are no “technologically feasible, economically reasonable” alternative methods of effectively treating these wastes to an acceptable quality level for discharge to streams. For these reasons, land disposal of sewage effluent and sludges now is being widely promoted and employed as the best available method of treatment.It is estimated that as many as 300 municipalities have gone to the land to solve their sewage plant waste problems in recent months. Many of these have been at least partially funded with State and Federal grants. If similar permits and financial assistance continue to be granted in the future, it is anticipated that several thousand municipalities will follow suit within the next few years.

Notes: The U.S. Geological Survey, in cooperation with the Nassau County Department of Public Works, recharged tertiary-treated sewage (reclaimed water) into the Magothy aquifer in 13 recharge experiments between 1968 and 1973. The recharge resulted in a degradation in water quality with respect to iron concentration and pH. Iron concentration increased from the range 0.14 to 0.30 milligrams per litre to as much as 3 milligrams per litre at the 20-, 100-, and 200-foot or 6.1-, 30-, and 61-metre observation wells as the reclaimed water displaced native water. The increase was presumably a result of pyrite dissolution. The pH of the water decreased from the range 5.22 to 5.72 to a low of about 4.50, predominantly as a result of cation-exchange reactions.

Notes: Biological activity occurring in subsurface regions below the soil zone may be of considerable importance in determining the fate and effect of pollutants in ground water, but this possibility has received little previous attention. This paper comprises a discussion of subsurface biological activity in regard to ground-water pollution as reflected by available literature references. The subsurface environment is discussed in terms of factors likely to be of greatest significance in regard to the development of biological systems, and previous investigations of subsurface microbial activity are reviewed. Available information indicates the presence in the upper continental crust of the earth of numerous regions, particularly those of sedimentary origin, which are probably suitable habitats for many microbial species. Previous investigations of subsurface microbial activity clearly show the presence of diverse microbial populations in many subsurface regions below the soil zone. Hence, microbial activity appears both possible and probable in most subsurface regions of importance in regard to ground water. Further elucidation of the extent and nature of microbial activity in subsurface regions is needed in developing methods for predicting the impact on ground-water quality of pollutants released into the earth's crust.