bluuebunny/crossref_metadata_2025 huggingface dataset:
State Ground‐Water Protection Programs — Adequatea
Authors: Ross Edwin H.
Published: July 2006

An assessment of the adequacy of State involvement should include a historical perspective of resource management in the nation. A review of the record indicates that up until the 70's, Federal policy was virtually nonexistent with respect to ground‐water protection programs.

Efforts of the ground‐water industry and related scientific community to gain legislative action has, within the last few years, shown progress within State government. The Federal EPA, in response to efforts of the only significant constituency, the NWWA, is now requiring ground‐water protection in their regulations.

Institutional arrangements, whether national, State or local, will at least for some years to come by political necessity require central involvement of the States in ground‐water protection.

The legislative and executive branch in many States have shown their willingness to act; however, without an active political constituency, legislative appropriations are provided after actual problems arise due to drought or contamination problems. Rainfall provides extra time to address quantity problems but there may not be a second chance to protect ground‐water quality. These branches of government have the monetary and legal authority to act once the need is demonstrated. The record of the judicial branch indicates a need for the legislative and executive branch to design and manage programs that will avoid the necessity of court action. Continued advocacy efforts for ground‐water protection programs yet remains the responsibility of the water well industry and a small ground‐water technical constituency. The public and the politicians need to be further informed and educated about the need for ground‐water protection.
State Ground‐Water Protection Programs — Inadequatea
Authors: Dawson James W.
Published: July 2006

The primary reason State ground‐water protection programs are inadequate is that the resource is misunderstood, surrounded by misconceptions and, due to its occurrence, is “out of sight and out of mind.” To most people, ground water is a very elusive and somewhat magical resource, whose significance in the over‐all picture of water resources has not been realized by those who have the power and authority to rectify the present state of affairs. The need for adequate protective legislation and sufficient financial and manpower resources commitment is even more difficult to justify because there has not, to date, been a citizenry outcry for such measures.

To ascertain the status of current State ground‐water protection programs, a survey of State legislation concerning ground water was undertaken; additionally, a questionnaire was sent to the agency in each State responsible for administration of ground‐water protection programs. The results of this survey indicate that most States have broad authority over ground‐water resources through general water resources legislation, but the majority do not have specific ground‐water protective legislation. In many cases, the broad legislative authority is inadequate or, if legislation is adequate, implementation of legislative mandates is not sufficient to provide adequate protection. Lack of ground‐water quality and quantity data is severe to the point that many agencies do not have a realistic characterization or identification of the ground‐water resources they are to protect.
The 208 Planning Approach to Ground‐Water Protection — A Foot in the Doora
Authors: Wallace Donna
Published: July 2006

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.
Waterborne Disease — A Status Report Emphasizing Outbreaks in Ground‐Water Systemsa
Authors: Craun Gunther F.
Published: July 2006

A total of 192 outbreaks of waterborne disease affecting 36,757 persons were reported in the United States during the period 1971‐1977. More outbreaks occurred in nonmunicipal‐water systems (70%) than municipal‐water systems; however, more illness (67%) resulted from outbreaks in municipal systems. Almost half of the outbreaks (49%) and illness (42%) were caused by either the use of untreated or inadequately treated ground water. An unusually large number of waterborne outbreaks affected travelers, campers, visitors to recreational areas, and restaurant patrons during the months of May‐August and involved nonmunicipal‐water systems which primarily depend on ground‐water sources. The major causes of outbreaks in municipal systems were contamination of the distribution system and treatment deficiencies which accounted for 68% of the outbreaks and 75% of the illness that occurred in municipal systems. Use of untreated ground water was responsible for only 10% of the municipal system outbreaks and 1% of the illness. The major cause of outbreaks in nonmunicipal systems was use of untreated ground water which accounted for 44% of the outbreaks and 44% of the illness in these systems. Treatment deficiencies, primarily inadequate and interrupted chlorination of ground‐water sources, were responsible for 34% of the outbreaks and 50% of the illness in nonmunicipal‐water systems.
Waterborne Disease — Historical Lessona
Authors: Markwood Ira M.
Published: July 2006

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.
Changing Patterns of Ground‐Water Use in the United Statesa
Authors: Zaporozec Alexander
Published: July 2006

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.
Modelling Rapid Flow in Aquifers
Authors: Rushton K. R. , Rathod K. S.
Published: July 2006

This paper examines the situation when, due to heavy rainfall, rapid transfer of water occurs in the upper highly permeable region of an unconfined aquifer. The conventional modelling approach of a single transmissivity, which either remains constant or increases with the saturated depth, is shown to be unsatisfactory. Instead it is necessary to consider the aquifer as consisting of two systems with flow always occurring in the primary system but only entering the secondary system during periods of high recharge. This is necessary because the velocities in the different regions of the aquifer are of significantly different magnitudes.

The Lincolnshire Limestone aquifer in England is used as an illustrative example. Initially a one‐dimensional approximation to the aquifer is considered so that the different features of the flow mechanism can be examined in detail. The method of dividing the recharge between the primary and secondary systems is shown to be of great importance. Then a preliminary two‐dimensional model of the whole region is considered. The model response is shown to be of the same form as that observed in the field and described in greater detail by Smith (1979).
A Study of the Reuse of Reused Water
Authors: Smith Edgar D. , Sweazy Robert M. , Whetstone George A. , Ramsey R. H.
Published: July 2006

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.
Tracing Subterranean Flow of Sewage‐Plant Effluent in Lower Ordovician Dolomite in the Lebanon Area, Missouria
Authors: Skelton John , Miller Don E.
Published: July 2006

In an area of faulted, cavernous, carbonate rocks of Ordovician age near Lebanon, Missouri, sewage‐treatment‐plant effluent was traced from Dry Auglaize Creek, a losing Ozark stream, to Sweet Blue and Hahatonka Springs in an adjacent basin. Rhodamine WT dye (20‐percent solution) was used to trace the subsurface movement of the effluent. Activated charcoal packets and grab samples of water were collected at 10 sites where dye might be expected to reappear and at a control site outside the area. The leading edge of the dye reached Sweet Blue Spring, a distance of 22.5 km from the injection point, 25 to 30 days after injection, and Hahatonka Spring, at a distance of 29.0 km, 45 to 50 days after injection. The apparent underground travel rate, based on straight‐line distances between injection and resurgence points, was 0.6 to 0.8 km per day.
Aquifer Coefficients Determined from Multiple Well Effects, Fernandina Beach, Florida
Authors: Bentley Craig B.
Published: July 2006

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 , 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.
Well Grouting and Casing Temperature Increases
Authors: Johnson Roy C. , Kurt Carl E. , Dunham George F.
Published: July 2006

Grouting of water wells is commonly done to increase the well life and to protect the water supply. When Portland cement‐based grouts cure, a by‐product of the process is heat of hydration which causes increased temperatures in the vicinity of the well casing. Since thermoplastic casing materials lose significant strength at elevated temperatures, it is important to know what range of temperature increases might be associated with the grouting operation.

A series of experiments has been performed to determine these temperature increases. Wells were simulated in the laboratory and temperatures monitored throughout the casing‐grout‐soil system. Results indicate that under certain circumstances the casing temperature could increase by as much as 180° F; however, for nominal 1 1/2‐inch grout thicknesses, casing temperature increases between 17° F and 26° F were measured.
Gravity Survey of a Deep Buried Valley
Authors: Stewart Mark T.
Published: July 2006

A gravity survey was conducted as part of a ground‐water investigation covering 400 mi2 (1,000 km2) in Outagamie County, northeastern Wisconsin. The objective of the gravity survey was to supplement bedrock topography data obtained from well logs and seismic refraction profiles. The gravity method was chosen as it is a rapid and low‐cost reconnaissance technique, and conditions in the study area were favorable for a successful gravimetric survey. The simple Bouguer gravity values were referenced to a local base station as only relative gravity values were required. The data were interpolated to a regular grid by an inverse‐distance weighted average algorithm. The gravity residual was derived using a five‐ring inverse weighted filtering routine. The residual map accurately reflects the major topographic features of the bedrock surface. A two‐dimensional geologic model fitted to the residual data agrees well with the simple flat plate approximation used to obtain quantitative estimates of glacial drift thickness. Estimates of drift thickness from the gravity data also agree well with bedrock depths obtained from well logs. The most productive drift aquifers are restricted to the major bedrock valleys. Gravity data were coupled with seismic refraction and well data to produce a bedrock elevation map, from which it is possible to predict the extent and distribution of the major drift aquifers.
Overflow Tests Analysed by Theoretical and Numerical Methods
Authors: Rushton K. R. , Rathod K. S.
Published: July 2006

The assumptions inherent in the theoretical analysis of constant drawdown overflow tests are difficult to achieve in practice. This paper shows that, even if there is a restriction in the flow which causes some delay in the achievement of the constant drawdown condition, the theoretical discharge curve is followed once the constant drawdown condition is reached. Recovery tests following overflow are also examined and it is shown that the discharge used in the calculation should be the discharge at the instant that the test is stopped. Further, it is demonstrated that if well and formation losses occur, the aquifer response is distinctly different from that of the theoretical analysis.

A brief description is given of an alternative method of analysis using a numerical model. A preliminary study of a field test yields promising results.
Methodology for Monitoring Ground Water at Uranium Solution Mines
Authors: Humenick Michael J. , Turk L. Jan , Colchin Michael P.
Published: July 2006

Monitoring the chemistry of ground water near in‐situ uranium leach mines is complicated by chemical variations unrelated to the mining operation that result from (1) spatial differences in the aquifer environment, and hence, in the water chemistry, (2) inconsistent or inadequate sampling procedures, and (3) errors in chemical analyses. Differences in the chemistry of water from place to place in the aquifer should be identified in pre‐mining baseline studies and must be taken into account during monitoring of the leaching operation, because natural waters of chemistry different from that established at a particular well during the baseline sampling period may be drawn into the monitoring well by pumping. The most important factor in developing proper sampling techniques is the configuration of the well and pumping equipment; if the pump intake is set near the point where water enters the well, and if the pumping rate is kept low to reduce turbulent mixing of waters in the well, it is not necessary to pump a full well‐bore volume before collecting a sample. Errors in chemical data can be eliminated by proper storage and handling of the samples and by careful checking of the analyses for chemical balance and eliminating the analyses that do not balance properly. Interpretation of the chemical data should be made only after assuring that these monitoring problems have been taken into account.
Ground‐Water Management in the High Plainsa
Authors: Wickersham Ginia
Published: July 2006

The High Plains region of mid‐America depends on ground water to a huge extent. A review of three States‐Texas, Colorado and Oklahoma—shows a disparity in ground‐water management in the region. Texas landowners own the ground water as a property right and the emphasis is on local management districts to control ground‐water use. Colorado, in contrast, has State control of ground water and regulation by permit from the State Engineer. Oklahoma is unique in tightly regulating ground water through limitations on pumpage, while still adhering to ownership by the individual landowner.

In spite of these differences, six of the High Plains States have united in a joint effort to study the ground water in the Ogallala. A $6 million study funded by EDA will evaluate the economic impacts of ground‐water mining and determine future water resources management in the region.
High Water Levels in Ground‐Water Dominant Lakes — A Case Study from Northwestern Wisconsin
Authors: Rinaldo‐Lee M. B. , Anderson M. P.
Published: July 2006

An investigation into the cause of high lake levels during the early 1970's in a ground‐water dominant lake in northwestern Wisconsin was conducted from December 1976 to July 1978, in part to address allegations by shoreline property owners that regulation of water levels in a reservoir 2.4 km south of the lake had caused the high lake levels. High lake levels also coincided with above average precipitation. Data collected during the study allowed the definition of the ground‐water flow system around the lake and the calculation of the water budget for the lake. Field data indicated that there is no ground‐water flow between the reservoir and the lake and that ground water flowing out of the reservoir is intercepted by a trough in the potentiometric surface. The trough is probably oriented along a permeable fault zone or a buried river valley. A ground‐water flow model was used to determine whether increased recharge rates of the magnitude that probably occurred as a result of above average precipitation in the early 1970's would be sufficient to account for the observed rise in lake level or whether regulation of the water level in the reservoir could be expected to affect lake level.
Convective Heat Transfer in Selected Geologic Situations
Authors: Kilty Kevin , Chapman David S.
Published: July 2006

There are many geological situations where moving ground water transfers a significant amount of heat. Yet, while convective heat transfer is a common phenomenon, it is very difficult to treat analytically. In this paper we present a simple model of convective heat transfer in porous materials and a numerical method of solving the model. The model is then applied to three diverse field situations: (1) a thermal anomaly on the Hartville uplift in eastern Wyoming; (2) a fault‐controlled hydrothermal system near Monroe, Utah; and (3) the Luanshya copper mine in the Republic of Zambia. In each case heat transfer by moving ground water is shown to explain the observed thermal anomalies satisfactorily. Our results indicate that in certain situations the effect of ground‐water flow needs to be considered in making local and regional assessments of heat‐flow data. Furthermore, temperature measurements can be very useful in estimating aquifer recharge, particularly when thermal conductivity and structural information are available.
The Deccan Basalts of Maharashtra, India —Their Potential as Aquifers
Authors: Deolankar S. B.
Published: July 2006

In order to study the potential of the Deccan basalts as aquifers, the properties of transmissivity and storativity must be considered. Analysis of large‐diameter dug wells tapping unconfined aquifers in the Deccan basalts shows that there exists a relationship between porosity and specific yield. The aggregate porosities of weathered basalts, vesicular basalts and fractured‐jointed basalts are respectively up to 34%, 50%, and 15%. On the contrary, specific yield has a maximum value of 7%, 4%, and 1% respectively. In relation to aggregate porosity the specific yield is low suggesting that in Deccan basalts effective porosity constitutes only a small fraction of aggregate porosity. It is found that this effective porosity is about 7%. The weathered basalts and vesicular basalts have higher transmissivities than fractured‐jointed basalt and, therefore, form better aquifers. The variation in transmissivity values in various directions, and from point to point, indicates that the Deccan basalts are hydrogeologically anisotropic and heterogeneous in nature.
Ground‐Water Use for Cooling: Associated Aquifer Temperature Changes
Authors: Lippmann Marcelo J. , Tsang Chin Fu
Published: July 2006

In steam‐electric power plants, large volumes of surface waters are used for cooling the plant's condensers. There, approximately two‐thirds of the energy produced by the fuel is removed as waste heat. This heat is carried away by the cooling waters, is dispersed into the atmosphere or surface‐water bodies, and is lost for other potential uses. When condenser cooling systems such as towers or ponds are used, there is also a considerable net loss of water through evaporation.

Injection and storage of spent cooling waters underground would reduce the evaporative (consumptive) losses to the atmosphere. Later, these waters could be recovered for use in heating and in industrial or agricultural applications. The resulting conservation of energy and water may make such a project economically feasible in the near future as the costs of water and fuel increase.

In this paper, we review the use of ground water from a confined aquifer for this application and analyze a simple configuration of one withdrawal and one injection well to determine: (1) the areal extent of temperature changes caused by reinjection of spent cooling waters into the aquifer from which they originated; and (2) how long it would take for the water to become too hot to use for cooling.
Monitoring Ground‐Water Contamination at a Fly Ash Disposal Site Using Surface Electrical Resistivity Methods
Authors: Rogers Robert B. , Kean William F.
Published: July 2006

Ground‐water quality has been monitored at a fly ash disposal site. The monitoring technique consists of electrical resistivity soundings, and profiles in conjunction with analysis of water samples from 33 wells on the site. In addition laboratory measurements were made on samples from the well borings to determine the changes in resistivity of each lithology as a function of water saturation, and the temperature and conductivity of the pore fluid.

For a line approximately perpendicular to the ground‐water flow, we were able to detail the subsurface lithology using electrical sounding, and in conjunction with the laboratory studies, it was possible to determine the vertical and horizontal extent of the contamination for that cross section.

Electrical profiles, which were taken on a monthly basis, were able to monitor the changing concentration of leachate after the profiles were corrected to a common ground‐water temperature.
Ground‐Water Modeling: Applicationsa
Authors: Mercer James W. , Faust Charles R.
Published: July 2006

The numerical models used in ground‐water studies are general computer programs that can be applied to a variety of hydrogeological conditions. These programs are based on approximations to the governing partial differential equations for ground‐water flow and transport. To use these models requires an understanding of the physical problem and field data. Although program input data and output results are quantitative, the appropriate application of numerical models remains a partly subjective procedure. To use models, the hydrologist must assess the merits of alternative numerical methods, evaluate available data, estimate data where missing or absent, and interpret computed results. The review of previous model applications can provide valuable insight on how these tasks may be approached.
Control of Ground‐Water Salinity, Orange County, California
Authors: Hammer Mark J. , Elser Gordon
Published: July 2006

The Orange County Water District in Southern California imports approximately 75 percent of its supply from aqueducts drawing waters from the Colorado River and Northern California. Twenty‐five percent comes from natural flow in the Santa Ana River and local precipitation. Only about one‐half of the aqueduct water is treated and distributed in pipelines. The other one‐half is applied to infiltration basins and ponds for ground‐water recharge. This allows communities within the District to draw ground water as their major supply, which is supplemented by aqueduct water purchased after treatment by the Metropolitan Water District of Southern California. The economic advantages of ground‐water recharge, as opposed to direct use of surface supplies, include eliminating water treatment, minimizing the size of pipe networks to distribute potable supplies, and reducing the requirement for storage reservoirs. However, using the basin aquifers as a reservoir to balance cyclic supply and demand creates two possible problems: excessive pumping lowers the fresh‐water table below sea level, and infiltration can result in a gradual increase in the level of dissolved salts in the ground water. Sea‐water intrusion has been greatly reduced by injection wells that provide a hydraulic barrier between the salt water and fresh inland water. Salt accumulation in the basin is a more serious long‐term problem since the salinity in the Colorado River water is increasing. Greater use of less salty Northern California water and reducing unwanted seepage of waste waters containing high dissolved solids are two of the remedial measures being implemented at present.
Pumping Test Analysis with a Handheld Calculator
Authors: Rayner Frank A.
Published: July 2006

The time‐consuming curve construction and, in some cases, curve matching, and the gross approximations of aquifer geohydrologic properties, can be supplanted by a simple, speedy, accurate, and inexpensive analysis of pumping test data by a handheld programmable calculator.

With such calculators—in actuality, minicomputers‐pumping test data can be analyzed within seconds, while the test is ongoing, and pumping test time and expense can be reduced, while still securing representative values for transmissivity and storage coefficients.
Ground‐Water Modeling: Recent Developmentsa
Authors: Faust Charles R. , Mercer James W.
Published: July 2006

Ground‐water modeling is an area of current research. As such, new techniques and applications continually evolve. In addition to being influenced by the necessity to solve certain problems, recent developments in modeling are influenced by the state of model evolution and computer capabilities.
Ground‐Water Flow and Uranium in Colorado Plateau
Authors: Ortiz N. V. , Ferentchak J. A. , Ethridge F. G. , Granger H. C. , Sunada D. K.
Published: July 2006

The precipitation of humates at the interface between a humic acid solution and an aluminum potassium sulfate solution was studied in porous media models to gain some insight into the deposition of Colorado Plateau type uranium deposits. The effects of variable flow rates, porous‐media layering, mudstone lenses, fluid density differences, and geochemical reactions on the flow phenomenon and the resulting precipitate were evaluated. A numerical model was developed to predict the shape and location of the interface where precipitation occurs. The numerical model was verified by comparing its predictions with the results obtained from the porous media model. The association of precipitate bands with modeled sedimentary features and the similarities between these precipitate bands and actual deposits in the Colorado Plateau suggest that these model studies provide data useful both in understanding and predicting the relations between tabular ore deposits and ground‐water flow patterns.
A Comparison of Nitrogen in Shallow Ground Water from Sewered and Unsewered Areas, Nassau County, New York, from 1952 through 1976a
Authors: Katz Brian G. , Lindner Juli B. , Ragone S. E.
Published: July 2006

Median nitrogen concentrations of ground water and water from streams in Nassau County were statistically analyzed on an areal and temporal basis and by individual well to compare concentrations of nitrogen in ground water beneath sewered and unsewered areas. The comparison is discussed in terms of hydrogeologic conditions and major point and nonpoint sources of nitrogen.

Although no significant differences in median nitrate concentrations during the 25‐year period of record were observed between the sewered and unsewered areas, recent (1972–76) ammonium and nitrate data suggest a relative improvement in water quality in the sewered area. This finding is based on (1) significantly lower ammonium and nitrate concentrations in stream water of the sewered area during base flow, (2) significantly lower median ammonium concentrations in ground water in the sewered area, (3) significant decreasing long‐term nitrate trends in water from 8 of 13 wells in the sewered area where records were sufficient for analysis, and (4) significantly lower median nitrate concentrations near the water table beneath the sewered area.

The lack of significant difference between median nitrate concentrations in the sewered and unsewered areas may be in part due to sampling bias and to the considerable length of time necessary for ground water in the sewered area, which was contaminated by cesspool and septic‐tank effluent before sewering, to reach a point of discharge in a stream or bay.

In addition, ammonium leached from landfills and nitrate originating from nonpoint sources such as fertilizers and animal wastes, cannot be removed by sewers and may be obscuring water‐quality improvements brought about by sewering.
An Evaluation of Sources of Nitrogen as Causes of Ground‐Water Contamination in Nassau County, Long Island
Authors: Porter Keith S.
Published: July 2006

An evaluation of sources of nitrogen in an urban area indicates that it may be difficult to distinguish effects on the quality of underlying ground water. In Nassau County two principal sources of nitrogen are human waste water and fertilized turf. The effects of these sources, combined with other sources such as domestic animals and precipitation, are such that management of one source, i.e. the removal of waste water via sewers, may be less effective than expected.
BASIN MANAGEMENT IN THE SAN BERNARDINO BASIN AREA
Authors: Rowe Larry W.
Published: July 2006

The San Bernardino Valley Municipal Water District was formed in 1954 to master plan the long‐term water supply, including the importation of supplemental water, for that portion of the Upper Santa Ana River Basin area within the District.

Prior to the development of a basin management program, the District first undertook to inventory the water resources available to it. Specifically, what is its quantity, distribution, quality, what stresses will the water supply be subjected to, and finally, how is it disposed of? To assemble and store this array of hydrologic data, the District, as part of its basin management program, has undertaken the creation of a hydrologic data base. To facilitate the storage and retrieval of all pertinent data, the District utilizes an on‐site high speed digital computer. Into this data base, the District has loaded all available information pertaining to ground‐water production, streamflows and diversions, rainfall, ground‐water levels, basin recharge, basin inflow/outflow, water quality, and consumptive use. Development and selection of alternative strategies is made more effective because of the availability of historic and real time hydrologic data. An additional benefit derived from the basin management program is that the updating of the operational economics associated with the importation of State Project water can be made with the benefit of the most current data available. This allows the District to optimize its programs and thus maximize the limited resources available to it.
Brine Pollution at Fresno — Twenty‐Six Years Later
Authors: Schmidt K. D. , Krancher J. A. , Bisel G.
Published: July 2006

Chloride pollution of ground water was discovered in 1953 downgradient of seepage pits and wells used for disposal of waste waters. An ice plant and water softening plant at the Fresno railroad yard were the sources of pollution. A plume of polluted ground water was delineated, and the discharge from the major source (the water softening plant) was stopped in 1953. Sampling in the late 1970's indicated that high chloride contents were still present in ground water downgradient of the railroad yard. The plume expanded both vertically and horizontally in the aquifer, from a volume of about 1,500 acre‐feet (1.85 million cubic meters) in 1953 to 15,000 acre‐feet (18.5 million cubic meters) in 1979. Trilinear diagram plots of waste waters and ground water indicate that waste water from the ice plant continued to produce an impact into the 1970's. Recharge from canal seepage has created an important boundary, particularly on the west side of the plume. The rate of ground‐water flow, calculated on the basis of the advance of the chloride front, was about 200 feet (61 meters) per year, in close agreement with estimates based on water‐level slope and aquifer parameters.
An Economical Approach to Determining the Extent of Ground‐Water Contamination and Formulating a Contaminant Removal Plan
Authors: Mido Kiyoshi W.
Published: July 2006

If past ground‐water movement in the vicinity of contamination could be shown pictorially, determination of the extent of contamination would be facilitated significantly. Furthermore, if pictorial representation of future ground‐water movement under presumed conditions reflecting alternative plans of contaminant removal or containment could be provided rapidly, an effective plan could be developed speedily and thus economically. A flow path and arrival time plot, which is developed through the use of a flow system kinematics mathematical model, provides such visualization of ground‐water movement. Contrary to the popular notion that the kinematics model requires much more geohydrologic datathan the finite difference or element models, it was found that meaningful kinematics models could be developed based on relatively limited data. Presented in this paper are: a brief description of the development of flow path and arrival time plots, information obtainable from such plots, an example of the use of the plots in determining the extent of contamination of ground water, and an example of the use of the plots in formulating a contaminant removal plan.
Ground‐Water Availability, Hockessin, Delaware
Authors: Williams Paul M.
Published: July 2006

A four‐year case study evaluation of the ground‐water availability in a small multiaquifer basin in northern Delaware has been performed to determine the hydrologic conditions when pumpage approaches the expected long‐term basin‐wide rate of ground‐water recharge. The basin is located in the Piedmont physiographic province and includes rocks of the Cockeysville marble and Wissahickon schist.

Only about one‐third of the basin (the marble area) contains favorable geologic conditions for large production well development (∼ 1 MGD/well); however, the entire basin serves as a recharge area for the marble sector. The manageable storage area is limited to the marble area; consequently, accurate ground‐water recharge and storage characteristics of this basin are critical to maximizing the long‐term yield while minimizing adverse impacts of pumpage. The analysis was performed using the Thornthwaite‐Mather water balance accounting procedure to determine the long‐term significance of the exported pumpage.
Resistivity Study of a Coastal Karst Terrain, Florida
Authors: Fretwell Judy D. , Stewart Mark T.
Published: July 2006

Twenty‐eight vertical electrical soundings were completed in the west‐central Gulf Coast area of Florida. The objective of the survey was to evaluate the resistivity method for locating the fresh‐water/salt‐water interface in the karstic Floridan aquifer.

Four geoelectric layers dominate the study area. The upper three are related to lithostratigraphy and correspond to: (1) surficial sands; (2) a karstic, highly‐transmissive carbonate zone; and (3) a less porous carbonate zone. The lowest layer represents a zone saturated with salt water and with a resistivity of less than one ohmmeter. Toward the coast, the fresh‐water/salt‐water interface rises, and fewer geoelectric layers are observed because pore‐water conductivity masks lithostratigraphic changes.

Interface data interpreted from resistivity measurements agree with other hydrologic data. The study indicates that surface electrical methods can provide information on the interface position and can provide hydrologic information between wells used for control.
Well‐Field Drawdowns Using Coupled Aquifer Model
Authors: Motz Louis H.
Published: July 2006

Well‐field drawdowns in the Jay B. Starkey Wilderness Park in southwestern Pasco County, Florida were investigated using a coupled aquifer model developed by Motz (1978). In the model, water pumped from an underlying artesian aquifer is derived from leakage through an overlying confining bed. It is assumed that the leakage is derived from a reduction in evapotranspiration from the overlying water‐table aquifer. This process is represented by a coefficient (e) that is a linear representation of the rate at which evapotranspiration is reduced per unit of water‐table drawdown. This investigation in the Jay B. Starkey Wilderness Park provides an example of how the hydrologic coefficients in the coupled aquifer model can be calibrated from observed pumping and water‐level data and how water‐table and artesian aquifer drawdowns resulting from an increase in the pumping rate subsequently can be estimated. A value of e = 1.12 × 10−3 gpd/ft3 (1.76 × 10−9 sec−1) was obtained by matching calculated water‐table drawdowns to water‐table drawdowns attributed to the pumping effects of five production wells in the western part of the park. Five alternative plans for expanding the well field were examined, and it was recommended that the central and eastern parts of the park be developed as a well field.
Interstate Conflict Over Ground Water: Wisconsin‐Illinois
Authors: Fetter C. W.
Published: July 2006

The Cambrian‐Ordovician aquifer (deep sandstone aquifer) of northeastern Illinois and southeastern Wisconsin consists of a number of hydraulically connected sandstone and dolomite units. The aquifer dips gently to the east beneath Lake Michigan and is regionally confined by the Maquoketa shale, which has been thinned and removed by erosion to the west. Recharge to the regional aquifer system occurs where the shale is missing and to a lesser extent across the shale wherever there are downward hydraulic gradients. The practical sustained yield from the aquifer is 46 million gallons per day (mgd) (170,000 m3/day) in Illinois and approximately 34 mgd (129,000 m3/day) in Wisconsin. In 1978, pumpage from the aquifer amounted to 142 mgd (537,000 m3/day) in the eight counties of northeastern Illinois compared with an estimated 38 mgd (144,000 m3/day) in Wisconsin. Pumpage in Illinois has exceeded the practical sustained yield every year since 1958 while in Wisconsin the practical sustained yield was reached about 1975. Two regional pumping cones have developed. One centered in the Chicago region has maximum drawdowns of more than 900 feet (275 m) while in the Milwaukee pumping cone water levels have fallen about 350 feet (106 m). The greater drawdown in the Chicago pumping cone has changed the regional hydraulic gradient and 9.3 mgd (35,200 m3/day) of ground water is now being drained from beneath Wisconsin into Illinois. A digital computer model of the aquifer system was used to separate the amount of total drawdown in the aquifer attributable to each pumping center as well as to predict future ground‐water levels. At the Illinois‐Wisconsin border in 1973, there was 265 feet (81 m) of drawdown of which 94 feet (28 m) were due to pumpage in Wisconsin and 171 feet (52 m) due to pumpage in Illinois. Allocations of Lake Michigan water to ground‐water users in Illinois could result in a reduction of pumpage to less than 46 mgd (174,000 m3/day) by 1985. In order to obtain a modification of the U.S. Supreme Court decree permitting Illinois to divert 3,200 cubic feet per second (cfs) (7,829,000 m3/day) of water from Lake Michigan, Illinois must agree that future allocations of Lake Michigan water will be done in such a manner as to reduce Cambrian‐Ordovocian aquifer pumpage. The rate of ground‐water decline will decrease substantially if this occurs. Water resources managers in southeastern Wisconsin should limit pumpage from the deep sandstone aquifer to approximately the current rate.
The Declining Ground‐Water Resources of Alluvial Valleys: A Case Study
Authors: Sophocleous Marios
Published: July 2006

The use of ground water increased rapidly in the Pawnee Valley, Kansas, during the last two decades, causing ground‐water levels to decline and streamflow to diminish. Therefore, this study was undertaken to evaluate the impact of present and future ground‐water withdrawals in the region. This report documents the depleting water resource of the area and calculates a preliminary hydrologic budget for the region. It also adapts, automatically calibrates, and applies a mathematical model that adequately simulates the operation of the hydrogeologic system for the purpose of evaluating several schemes for managing the ground‐water resource. Two different estimates of regional ground‐water recharge in the area indicated that the average natural recharge is approximately 0.5 inch per year. On the other hand, it was found that the amount of appropriated ground water in the area exceeded the natural recharge figure by about 11 times. Digital simulations of the aquifer system indicated that, even without any additional development or with very wet periods, water‐level declines will continue indefinitely, since ground‐water withdrawals in the Pawnee Valley are of such magnitude. One option put forth for consideration is to prolong the life of the ground‐water resource through the application of all the following recommendations: concerted efforts to reduce water wasting and to increase efficiency of water use; implementation of not more than a 40 percent saturated‐thickness depletion allowance for the next several years; imposition of a freeze on the number of irrigation wells to the present levels; and engagement in an artifical‐recharge program.
Impact of Dredged Material Disposal Upon Ground‐Water Quality
Authors: Morrison Robert D. , Yu Kar Yuk
Published: July 2006

A two‐year ground‐water monitoring program at three upland dredge disposal sites in the United States was conducted to determine whether the sites were contributing to ground‐water degradation. Facilities were located at Grand Haven, Michigan, Sayreville, New Jersey, and Mobile, Alabama. Leachate samples were collected from vacuum/pressure lysimeters and ground‐water wells. Ground‐water wells were situated directly under the fill, downgradient, and in an area representative of indigeneous ground‐water quality. Analyses of 27 parameters from 10 sampling periods indicated that calcium and manganese represent major water quality problems due to their contribution to water hardness. Of the trace metals, manganese and iron were found to exceed recommended EPA drinking‐water quality standards at all sites. Levels of potassium, total organic carbon (TOC), chloride, sodium, calcium, alkalinity, and magnesium appear to affect local ground‐water quality. Possible controlling mechanisms for observed leachate concentrations for these parameters include absorption, adsorption, ion exchange complexation, dilution and biological activity.
Ground‐Water Recharge from Rectangular Areas
Authors: Rao N. H. , Sarma P.B.S.
Published: July 2006

The formation of ground‐water mounds in response to recharge from ponds has been described earlier by equations that have been developed for infinite aquifers. In this paper, an equation for the formation of ground‐water mounds on recharge from a rectangular area to a finite aquifer was derived. The validity of the equation was tested by comparison with field data of recharge from square ponds. The solution derived here appears to describe the actual field response of water table to recharge better than the equation derived for infinite aquifers.