bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Waste Treatment/Disposal Site Evaluation Process for Areas Underlain by Carbonate Aquifers
Authors: Magner J.A. , Book P.R. , Alexander E.C. 
Published: February 2007

AbstractFractured carbonate or karst aquifers are highly susceptible to contamination. In Minnesota, the areas underlain by karst aquifers are often characterized by thin soil cover, poorly cased wells and/or collapse features. When coupled with improper land use decisions these aquifers have become extensively contaminated.Evaluation of existing or potentially contaminated sites has required development of unique site evaluation techniques or combinations of techniques. Shallow geophysics have been used successfully to determine subsurface karst features, pinpoint locations for additional investigations and evaluate pump‐test data. Soil texture, density and relative moisture content have been closely examined and criteria established to evaluate subsurface erosion susceptibility. Percent rock core recovery, mechanical response of drilling and drilling fluid loss have been used to characterize the secondary porosity and potential contamination susceptibility of the carbonate rock. Dye tracing via surface sinks and well injection have determined primary flow paths and have been useful in estimating flow times.These techniques used solely or in conjunction have been very useful in evaluating contamination existing in the aquifers and as a predictive tool to evaluate the proposed land uses impacts.
A Comparison of Ground Water Monitoring Data from CERCLA and RCRA Sites
Authors: Plumb Russell H. 
Published: February 2007

AbstractGround water quality data generated during the investigation of 334 hazardous waste disposal sites were used to contrast the Resource Conservation and Recovery Act (RCRA) and Comprehensive Emergency Response, Compensation and Liability Act (CERCLA) monitoring. programs. The minimum RCRA‐required network of four wells was equaled or exceeded at 94 percent of the 156 RCRA sites and 70 percent of the 178 CERCLA sites in the data base. A sampling frequency of four events per year or more was used at 60 percent of the RCRA sites compared to only 24 percent at the CERCLA sites. CERCLA records compiled to date indicate that 480 compounds have been detected and another 220 compounds have been tentatively identified in ground water in the vicinity of hazardous waste disposal sites. However, the composite data from 123 RCRA site monitoring programs only indicates the presence of 100 chemical substances. The most significant discrepancy in the RCRA detection monitoring program is that it only generates data on three of the 20 organic contaminants that have been most frequently detected during the CERCLA hazardous waste disposal site investigations. Modification of the current RCRA program to include routine analysis for volatile organic compounds would correct this weakness.
Minimizing Interpretation Ambiguities Through Joint Inversion of Surface Electrical Data
Authors: Gustafson Edward P. , McEuen Robert B. 
Published: February 2007

AbstractJoint inversion is an extension of standard least‐squares inversion techniques. With this approach, it is possible to construct a model that is simultaneously consistent with surface observations made using more than one geophysical method. Specifically, discussion focuses on applications to the Schlumberger and audiomagnetotelluric sounding methods, although the technique is not limited to these.The authors have found that the non‐uniqueness problems that often plague the interpretation of electrical sounding data can be substantially reduced if the model is required to be consistent with more than one set of surface measurements. If geological ground truth is available to further constrain the model, the chances of arriving at the true physical property distribution of the subsurface are far better than if a single data set is interpreted.To demonstrate the power of joint inversion, the authors present a study using synthetic data obtained from a three‐layer resistivity model. Finally, two case histories are presented to demonstrate that a much better representation of the true earth can be obtained with joint inversion than with standard interpretation methods.
Interceptor Trenches for Positive Ground Water Control
Authors: Gilbert Seward G. , Gress James J. 
Published: February 2007

AbstractInterceptor trenches are an effective ground water control method at waste management sites. Trenches may be installed without disturbing the wastes, and the withdrawal of ground water recovers contaminants that have left the waste management perimeter. The rapid and steep depression of the piezometric surface on both sides of the trench is positive proof of a barrier to horizontal flow across the trench in the affected permeable units.Historically, the construction of interceptor trenches has been very difficult. A new and efficient installation method has been developed and successfully utilized for several applications at a petrochemical facility on the Texas coastal plain. Rapid and cost‐effective installation is made possible by innovations in sump and trench construction and the tie‐in between the two.The sump is constructed first using standard well construction techniques to drill a 96‐inch diameter hole to contain the 42‐inch diameter polyethylene pipe sump. A European designed and fabricated trenching machine then excavates the trench, inserts the drainage pipe and backfills with sand and/or gravel in one operation. A specially designed perforated pipe entry door built into the side of the sump barrel provides for efficient and safe connection of the drainage pipe to the specially designed collection sump. The effectiveness of interceptor trenches has been confirmed in full scale applications through the reversal of flow gradients and the prevention of continued horizontal migration of ground water contaminants.
A Comparison of Office‐Derived vs. Field‐Derived Water Table Maps for a Sandy Unconfined Aquifer
Authors: Blanchard Margaret C. , Bradbury Kenneth R. 
Published: February 2007

AbstractThis study compares the accuracy of two types of water table maps both of which were constructed with the object of optimizing future mapping efforts in similar environments. The. first type of map is based solely on office information, with no field verification. The second type of map is based on careful field mapping using numerous measurement points.The office‐derived maps were based on topography, surface water features, existing reports, maps and data in the files of the Wisconsin Geological and Natural History Survey; the data were not field‐verified. The field‐derived maps used a dense network of 236 piezometers at 176 sites in an area of approximately 170 square miles. The field project was much more expensive and labor‐intensive than was the construction of office‐derived maps for the same area.The two methods produce water table maps which agree to an appreciable extent, the greatest agreement being in areas having ground water‐fed streams. Differences in water table elevations indicated by the two methods range from negligible to approximately 5 feet. Thus, depending upon the availability of existing information, relatively accurate water table elevations can be delineated in similar sandy unconfined aquifers without time‐consuming and expensive field work that drilling and piezometer installation entails.Preliminary construction of office‐derived water table maps enables researchers to use their resources efficiently. In some situations, expensive installation of wells and piezometers for a regional monitoring network may add little accuracy to the regional map. For localized problems, collection of additional field data will always be necessary, but can be guided by the office‐derived maps. The authors caution that this technique may only be applicable to sandy, unconfined aquifers in humid climates.
Interim Private Water Well Remediation Using Carbon Adsorption
Authors: Hall Daniel W. , Mumford Robert L. 
Published: February 2007

AbstractGasoline spills or underground tank leaks can cause ground water contamination that affects nearby private wells. The volatile organic constituents of gasoline can render the well water unfit for consumption, based on recommended health advisory limits for benzene, ethylbenzene, toluene and xylenes. Ground water investigations and remedial actions can become prolonged situations, during which the well owner may not be able to use his well. Carbon adsorption can be used as an interim remedial action to remove volatile organics and normalize use to well owners, until long‐term solutions can be implemented. Small‐scale carbon units are adaptable to private well plumbing.Contamination of private wells by a gasoline station near Wausau, Wisconsin, provided the opportunity to test the ability of carbon adsorption to effectively treat well water. The gasoline contamination is an isolated problem within an area of Wausau that is the subject of a state‐led Environmental Repair Fund (ERF) investigation. Long‐term solutions to the gasoline problem have been delayed until completion of present investigations. Carbon adsorption was recommended as an interim remedial measure at two private wells affected by the gasoline contamination.The concentrations and types of organic compounds in the water determine the cost‐effectiveness of using carbon adsorption as an interim remedial measure. Each organic compound has a characteristic affinity for a particular carbon, which ultimately determines the life of the carbon adsorption unit before carbon replacement is necessary. Water quality testing for volatile organics at the private water supply wells indicated the type and concentration of gasoline‐related contaminants.The data were used to conservatively estimate the expected life of the carbon adsorption unit. Continued periodic water quality analyses determine the actual carbon tank life.Data collected as part of the study indicate that the carbon adsorption systems initially functioned beyond their estimated capacities and successfully removed organics from the affected water supplies. One well required additional treatment to optimize effective carbon system performance, and to solve an iron discoloration and taste problem. This well also experienced carbon system breakthrough by volatile organics, which required lowering the carbon tank change interval.
Ground Water Quality Monitaring: The Arkansas Approach
Authors: Desmarais Ralph 
Published: February 2007

AbstractMonitoring ground water quality on a statewide basis is a challenge being faced by a number of state and federal agencies involved with water quality. Many of these agencies have come forth with publications that are of some use to those who are engaged in developing monitoring networks. A review of this literature could save those involved much time and money by providing insight into what can be accomplished and/or avoided. Ultimately, each monitoring system has to be designed to meet the purposes and conditions for which it is created, no two situations ever being exactly alike. However, there are approaches and methods that can be borrowed and profitably utilized where both the problems confronted and the geology in which they are found are similar. It was the attempt to resolve these two conflicting tenets, situational uniqueness and methodological transferability, that impelled the state of Arkansas to develop the prototype approach that is to be described, along with some of the more important documents that were of use in the development of that approach.Figure I highlights the main tenets of the prototype approach and Figure II locates each prototype within the state of Arkansas.
Drill‐Through Casing Driver Drilling Method for Construction of Monitoring Wells in Coarse, Unconsolidated Sediments
Authors: Woessner William W. 
Published: February 2007

AbstractHole stability problems occurring during construction of monitoring wells in coarse, unconsolidated alluvium can be overcome by using a drill‐through casing driver mounted on a standard top‐head drive rotary rig. Steel casing is driven contemporaneously with drilling, providing continuous hole stability. Samples of aquifer material and ground water can be taken at discrete depths as drilling proceeds. Monitoring well completion is accomplished by: (1) using the steel casing as an open‐ended piezometer; (2) installing a telescoping well screen; (3) plugging the casing end and perforating desired intervals, (4) installing one or more smaller diameter wells, and then (5) pulling back the steel casing. Advantages of this drilling method include maintenance of hole stability during drilling and well completion, faster borehole construction time than traditional methods in coarse alluvial deposits and other poorly sorted formations, and collection of representative samples of the geologic formations and ground water; additionally, drilling fluids are not required.
Ground Water Monitoring in the U.S.S.R.
Authors: Zaltsberg E. 
Published: February 2007

AbstractGround water monitoring is considered to be a significant component of the geological service in the U.S.S.R. Currently, the total number of ground water monitoring wells exceeds 30,000. They are divided into two categories, which are the first class, or basic observation wells, and the second class, or auxiliary observation wells. The main objectives of both monitoring networks are briefly described. The general scheme of ground water monitoring organization is also presented.
Vadose Zone Monitoring: An Early Warning System
Authors: Kirschner Frederick E. , Bloomsburg George L. 
Published: February 2007

AbstractCurrently, vadose zone monitoring is required under the Resource Conservation and Recovery Act (RCRA) only at land treatment facilities. Contaminant leak detection through ground water monitoring is very important, but it is considered to be after the fact. Remedial action costs can be reduced considerably by monitoring the vadose zone for compounds that exhibit high rates of movement. Volatile organic compounds (VOCs) exhibit this property and are present at many municipal landfills, recycling facilities, and treatment storage and disposal facilities (TSDFs). Through the authors’personal experience, it has been noted that gaseous phase transport of VOCs through the vadose zone is at least an order of magnitude greater than advective transport of VOCs in ground water. Therefore, VOCs in soil gas are an effective early warning leak detection parameter. Downward movement of leachate can be intercepted by porous cup lysimeters. Attenuation in the vadose zone slows the apparent movement of contaminants; however, it is only a matter of time before leachate reaches the water table. The authors believe that soil‐gas and pore‐water monitoring should and eventually will be required at all RCRA sites. If vadose zone monitoring becomes an additional requirement under RCRA, both the facility owner and the taxpayer will benefit. During the interim, facility owners can benefit by employing vadose zone monitoring techniques coupled with either qualitative or quantitative chemical analyses.
The Sensitivity of Four Monitoring Well Sampling Systems to Low Concentrations of Three Volatile Organics
Authors: Schalla Ronald , Myers David A. , Simmons Mary Ann , Thomas John M. , Toste Antony P. 
Published: February 2007

AbstractFour state‐of‐the‐art ground water sampling systems were analyzed to determine their reliability in providing representative samples of the volatile chlorinated hydrocarbons trichloroethylene (TCE), perchloroethylene (PCE), and 1,1,1‐trichloroethane (TCA) from a simulated monitoring well. The sampling systems studied represent four commonly used devices, including a stainless steel and Teflon® piston pump, a Teflon bailer, a Teflon bladder pump, and a PVC air‐lift pump.Controlled laboratory sampling experiments were conducted in a tank and well test chamber designed to approximate field conditions. A well purging and sampling procedure was used in the test apparatus to determine the accuracy and precision of each device for detecting low concentrations of the compounds in ground water. The compounds selected are some of the most ubiquitous hazardous contaminants found in shallow aquifers near hazardous waste sites throughout the United States.No significant statistical difference was found among the four sampling systems in detecting the compounds.
Hydrogen Peroxide Treatment of Septic Systems and Its Negative Effects on Shallow Ground Water
Authors: Bicki Thomas J. 
Published: February 2007

AbstractSoil‐solution samplers and shallow ground water monitoring wells were utilized to monitor nitrate movement to ground water following H2O2 application to a clogged soil absorption system. Nitrate‐nitrogen concentrations in soil water and shallow ground water ranged from 29 to 67 mg/L and 9 to 22 mg/L, respectively, prior to H2O2 treatment. Mean nitrate‐nitrogen concentrations in soil water and ground water increased and ranged from 67 to 115 mg/L and 23 to 37 mg/L, respectively, one week after H2O2 application. Elevated concentrations of nitrate‐nitrogen above background persisted for several weeks following H2O2 treatment. The H2O2 treatment was unsuccessful in restoring the infiltrative capacity of a well‐structured soil. Application of H2O2 to the soil absorption system poses a threat of nitrate contamination of ground water and its usefulness should be fully evaluated before rehabilitation is attempted.
Statistical Issues and Problems in Ground Water Detection Monitoring at Hazardous Waste Facilities
Authors: McNichols Roger J. , Davis Charles B. 
Published: February 2007

AbstractGround water monitoring presents interesting statistical challenges, including controlling the risk of entering compliance monitoring, incorporating all modes of inherent variability into the statistical model on which tests are based, and taming the detection limit problem, all while maintaining demonstrable sensitivity to real contamination.Some of these challenges exceed textbook statistics considerably, even when considered alone, and good solutions are scarce. When these challenges are combined, the task of developing good statistical procedures or good regulations can be formidable.This article presents a number of realities of ground water monitoring that should be considered when developing statistical procedures. Recommendations made for addressing these realities include the following: (1) the false positive rate should be controlled on a facility‐wide basis, rather than per well or per parameter as required in the proposed regulation (40 CFR §264); (2) multiple comparisons with control procedures are preferable to analysis of variance (ANOVA) for controlling the overall false positive rate; (3) retests can be made an explicit part of the statistical procedure in order to increase power and decrease sensitivity to distribution shape assumptions; (4) commonly used simple methods of handling below detection limit data with parametric tests, including Cohen's procedure as implemented in the U.S. EPA's Technical Enforcement Guidance Document (TEGD), should probably be avoided; (5) the statistical properties of practical quantitation limits for non‐naturally occurring compounds should be studied carefully; and (6) so long as the facility‐wide false positive rate is controlled, better sensitivity to real contamination is obtained by monitoring fewer well‐chosen parameters at a smaller number of well‐chosen locations.An evaluation of the proposed revised §264 regulation with respect to these realities reveals that it seems to be a definite improvement over the current regulation, but that it may be quite difficult to develop an adequate statistical plan within its constraints.
Contamination of the Sandstone Aquifer of Prince Edward Island, Canada by Aldicarb and Nitrogen Residues
Authors: Priddle M. W. , Jackson R.E. , Mutch J.P. 
Published: February 2007

AbstractPrince Edward Island is wholly dependent upon ground water from a highly permeable fractured sandstone aquifer for all industrial, domestic, agricultural, and potable uses. The contamination of this aquifer by agricultural residues, principally aldicarb and nitrate, has caused concern among Islanders. Ground water quality was monitored between 1985 and 1988 beneath two potato fields to which aldicarb (Temik) was applied at planting once or twice between 1983 and 1986. In May of 1988,12 percent of 48 monitoring well samples exceeded the drinking water guideline of 9μg/L for total aldicarb. Furthermore 32 percent of all samples exceeded the nitrate guideline of 10 mg/L. Aldicarb persistence appears related to its application at planting when soil temperatures are low and recharge is high and to the inhibiting pH effect that ammonium (from fertilizers and soil organic nitrogen) oxidation has on its degradation. Therefore, based on the research of others, it is recommended that aldicarb be applied at plant emergence when degradation is more rapid and recharge is lower.
Availability and Content of Domestic Well Records in the United States
Authors: Ganley Mary C. 
Published: February 2007

AbstractGround water professionals within public and private sectors use well records as data sources. Both the availability and the technical content of domestic well records in the 50 states are of interest to them. Well record availability is dependent on legal requirements, filing systems, databases, and storage places. Forty‐six states have statewide regulations or other legal requirements for filing completion reports for domestic wells. Fifty‐one agencies across the country maintain domestic well records. Filing systems involve location, chronology, date, or number information. Thirty‐one of the 51 agencies maintain varying types of databases containing record information or data related to the records. Overall, records are kept in central offices in 43 states and in regional offices in three states.The technical content of the records was evaluated for general, location, hydrogeology, and well construction information to assess the relative value of the records for use in national pesticide surveys. Technical information tabulated from the well records collected for this paper included nine items in a general category, 28 items in a well‐construction category, eight items in a hydrogeology category, and six items in a location category. Items in the general and location categories identified the well location and ownership. Construction category items include those describing well‐construction parameters such as grout, casing, and screen. Hydrogeology category items include static water level, aquifer media, and estimated yield. The three items always requested were owner's name, driller's name, and static water level. The three least‐requested items, ranging from 16 percent to 10 percent, were packers, drilling fluid, and geologic formation.
Assessing Arkansas Ground Water for Pesticides: Methodology and Findings
Authors: Cavalier T.C. , Lavy T.L. , Mattice J.D. 
Published: February 2007

AbstractDuring 1985 to 1987, 119 wells, Springs and municipal drinking water supplies throughout Arkansas were monitored for the presence of pesticides. Pesticides selected for analysis included acifluorfen, alachlor, aldicarb, atrazine, benomyl, cyanazine, cypermethrin, 2,4‐D, dichlorprop, diuron, fenvalerate, fluometuron, hexazinone, linuron, metolachlor, permethrin, picloram, and propanil. Not every sample was analyzed for every pesticide. Overall, results indicated that the 18 herbicides, fungicides, and insecticides were not present in the ground water samples studied. (Note: Detectable concentrations of three herbicides – alachlor, atrazine, and metolachlor – were found in one irrigation well, at 5.5,5.8, and 6.9 μg/L, respectively. However, since previous and subsequent sampling failed to detect these compounds, their presence is attributed to a localized spill or handling error rather than agricultural application.)