bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field Methods for Measurement of Ground Water Redox Chemical Parameters
Authors: Walton‐Day Katherine , Macalady Donald L. , Brooks Myron H. , Tate Vernon T. 
Published: February 2007

AbstractAn inexpensive, versatile, and portable system is presented, which facilitates rapid field determinations of redox potentials, pH, conductivity, ferrous and total iron, nitrite, specific conductance, dissolved oxygen, and temperature. Accuracy is facilitated by on‐site measurements of most parameters using specially constructed flow‐through cells and, for several analyses, sealed reagent ampoules, which can be broken and developed inside a flowing stream of ground water. Coupled with laboratory analyses of more stable ground water parameters, this system can provide accurate and relatively inexpensive determinations of redox conditions in ground water.
Temporal Variations of Chlorinated Solvents in Abstraction Wells
Authors: Rivett Michael O. , Lerner David N. , Lloyd John W. 
Published: February 2007

AbstractData obtained during an organic water quality survey of abstraction (pumping) wells in the Triassic Sandstone Aquifer of Birmingham (U.K.) indicate that there are important variations of chlorinated solvent concentrations with time. Short‐term observation of solvent concentrations with elapsed pumping time indicates widely differing well responses; such observations are important in establishing good sampling protocols. Long‐term monitoring indicates that solvent concentrations, particularly trichloroethene, are often stable with time. When large solvent variations do occur, these are shown to be due to the variation in the abstraction history of the well or significant migration of solvent plumes during the monitoring period. The latter effect is particularly exemplified by rising trends in 1,1,1‐trichlroethane concentrations. The changes observed in solvent concentrations during long‐term monitoring of the Birmingham Aquifer are slow to occur, but often large.
Monitoring Ground Water for Pesticides at a Golf Course ‐ A Case Study on Cape Cod, Massachusetts
Authors: Horsley Scott W. , Moser John A. 
Published: February 2007

AbstractThe town of Yarmouth, Massachusetts, proposed to locate a new municipal golf course within a delineated area of recharge to public water‐supply wells. Two concerns of town officials were (1) hydrologic impacts upon downgradient wells; and (2) water‐quality impacts from fertilizers and pesticides. In response to these concerns, a thorough hydrogeologic investigation was made, fertilizer and pesticide management programs were recommended, and a ground water monitoring program was developed.The golf course parcel was determined to be underlain by a sand and gravel aquifer composed primarily of glacial outwash. Water‐table maps confirmed that ground water flow was in the direction of several public water‐supply wells. A three‐dimensional finite‐difference flow model was used to determine the optimum location and pumping rates for irrigation wells. Potential nitrate‐nitrogen concentrations in the ground water were predicted to range from 5.0 to 7.9 milligrams per liter so slow‐release fertilizers were recommended.With the assistance of the EPA Office of Pesticide Programs, the list of proposed pesticides was reviewed and sorted into three categories based on the known leachability, mobility, and toxicity characteristics of each compound. Specific recommendations were made as to pesticide selection and application rate using that classification.A monitoring program was developed to provide an on‐going assessment of any effects on water quality related to the application of fertilizer or pesticide. The elements of the monitoring program include (1) specifications for monitoring wells and lysimeters, (2) a schedule for sampling and analysis, (3) specific concentrations of nitrates or pesticide compounds that require resampling and analysis, restriction of usage, or remedial action, and (4) regular reports to the Yarmouth Water Quality Advisory Committee and to the Yarmouth Water Department. In an effort to ensure the implementation of this program, a table of responsibilities was prepared, and a Memorandum of Understanding adopting the program was signed by the town agencies interested in water‐supply protection and the golf course operation.The monitoring facilities were installed with minimal problems as part of the golf course construction tasks. However, implementation of the sampling and analysis part of the program was accomplished only after some difficulty and delay. The assistance of the State Pesticide Bureau, the University of Massachusetts Department of Entymology, and the Massachusetts Pesticide Laboratory was enlisted when budgetary problems threatened to prevent implementation. It is apparent from Yarmouth's experience that the mere preparation of a plan is not sufficient by itself. Consultants who prepare the plan should make every possible effort to include implementation in their scope of services.
Ground Water Contamination at Wood Treatment Facilities
Authors: Rosenfeld Jeffrey K. , Plumb Russell H. 
Published: February 2007

AbstractGround water contamination profiles from five wood treatment facilities across the country have been compared. The distributions of organic priority pollutants at the five sites are similar, with the most common contaminants being polynuclear aromatic hydrocarbons and phenolic compounds. These contaminants are the predominant constituents of creosote, which is a common wood preservative. Inorganic contaminants have also been detected at these sites, but their distributions are not uniform across all sites. The distributions of the organic priority pollutants at the five sites appear to differ from those at other hazardous waste sites. Suggested recommendations for choosing monitoring parameters for wood treatment facilities are presented.
An Analysis of Nitrate‐Nitrogen in Ground Water Beneath Unsewered Subdivisions
Authors: Tinker John R. 
Published: February 2007

AbstractWater samples from private water supply wells in five unsewered subdivisions were tested for nitrate‐nitrogen to determine the possible impact of septic systems on ground water quality. Three subdivisions are located in Eau Claire County and two in LaCrosse County, Wisconsin.The nitrate‐nitrogen concentrations in the wells were analyzed in relation to ground water flow direction, the location of septic systems within the subdivision, and the hydrogeologic and physical characteristics of the subdivisions. A comparison of three nitrogen mass balance models helped to identify the possible sources of nitrate‐nitrogen in the wells.The results indicate that nitrogen from septic systems and lawn fertilizer cause nitrate‐nitrogen to increase in the ground water beneath the downgradient side of the subdivisions. In three of the five subdivisions the highest nitrate‐nitrogen value exceeds the drinking water standard of 10 mg/L.
The Effect of Latex Gloves and Nylon Cord on Ground Water Sample Quality
Authors: Canova Judy L. , Muthig Michael G. 
Published: February 2007

AbstractEighteen sites in South Carolina under investigation by the Superfund program were sampled to determine ambient ground water quality. Samples from 11 of 15 monitoring wells sampled with a bailer contained either caprolactam or Santowhite® (a registered trademark of the Monsanto Co.) or both organic compounds. A maximum of 540 μg/L of caprolactam and 780 μg/L of Santowhite was observed in the samples from the monitoring wells. None of the samples collected using dedicated submersible pumps at 28 other wells contained either compound.Caprolactam is used in the manufacturing of nylon cord, and Santowhite is used as an antioxidant in latex gloves. Therefore, it was suspected that the nylon cord used to raise and lower the bailer and the latex gloves that were worn during sampling may have contributed the caprolactam and Santowhite to the sample.An experiment using pH‐adjusted distilled water and private well water revealed that the nylon cord and the latex gloves may contribute contaminants to ground water samples. Research is needed into the potential for caprolactam and Santowhite to interfere with laboratory analyses in addition to the potential for absorption of contaminants by nylon cord. Until additional information is available, alternative materials or sampling techniques should be considered to minimize the potential impact of nylon cord and latex gloves on the quality of bailed samples.
A New Sampling System for Obtaining Relatively Undisturbed Samples of Unconsolidated Coarse Sand and Gravel
Authors: McElwee CD. , Butler J.J. , Healey J.M. 
Published: February 2007

AbstractGeologic site characterization is an important issue that must be addressed if details of contaminant transport in the subsurface are to be understood and predicted. Ideally, the formation heterogeneities at a site must be characterized at several scales. This paper deals with the smallest practical scale: core samples with cross‐sectional dimensions of a few inches. Historically, there has been great difficulty in obtaining relatively undisturbed cores of Unconsolidated coarse sand and gravel. In this study, 23 wells were installed at a field site in the Kansas River alluvium with hollow‐stem auger techniques. Six of these wells were cored through about 30 feet of coarse sand and gravel at depths of 40 to 70 feet using various techniques. A modified Waterloo sampler was employed with good success, using drilling mud in the auger flights to control heave and help hold in the sample. However, the use of heavy drilling mud has disadvantages (for example, the potential to contaminate the aquifer and cores) and recovery without sample loss is difficult because the procedure is sensitive to vibration and other mechanical forces. Without the use of drilling mud, the modified Waterloo sampler design was unsatisfactory because of relatively low recovery. In order to address this limitation, new sampler designs were developed and field tested. The most promising design does not require drilling mud, achieves a high recovery, and is not as sensitive to vibration and mechanical forces during recovery. The new design incorporates an inflatable bladder, located in the drive shoe, which closes off the end of the sampler. The deflated rubber bladder lies behind a plastic sample liner as the core begins to enter the sampler. Near the end of the 5‐foot sample drive, a piston extension triggers a release mechanism and allows a 4‐inch retraction of the plastic liner, resulting in the bladder being in direct contact with the sediment. The bladder is then inflated from the surface with nitrogen gas, closing off the bottom of the sampler and allowing recovery with minimal opportunity for sediments to fall out. Using this sampler, we have been able to consistently achieve about 86 percent out of a possible 90 percent recovery (drive shoe loss is 0.5 feet out of 5 feet due to bladder length and placement). The remaining 4 percent loss is due to compaction, premature piston movement, or wall friction preventing material movement into the sampler. These cores have been evaluated in the laboratory for determination of hydraulic conductivity, porosity, density, and particle‐size fraction.
A Multilevel Ground Water Monitoring System for Casing Advance and Bedrock Drilling Methods
Authors: Boyle D.R. 
Published: February 2007

AbstractA single‐hole multilevel sampling piezometer system (MLSPS) has been designed by the Geological Survey of Canada (GSC) to be installed using drilling systems that continuously core (e.g., Rotosonic) or continuously sample (e.g., hollow‐stem auger, Becker hammer) overburden and that have the flexibility of allowing additional coring (diamond drilling) or sampling (hammer drilling) of bedrock. The GSC‐MLSPS (under license to Solinst Canada Ltd.) uses a patented GSC dry injection system for accurate emplacement of filter packs and seals. This system permits (a) the use of variable screen lengths; (b) the complete evacuation of piezometers before introduction of new ground water (no bailing); (c) the use of a number of types of hydraulic tests (e.g., slug, withdrawal/recovery, vacuum, pressure‐pulse); (d) ground water sampling under a nitrogen atmosphere; (e) dissolved gas sampling; (f) a great deal of flexibility in the use of design materials; and (g) the elimination of bridging and collapse of filter packs and seals.
The Application of In Situ Air Sparging as an Innovative Soils and Ground Water Remediation Technology
Authors: Marley Michael C. , Hazebrouck David J. , Walsh Matthew T. 
Published: February 2007

AbstractVapor extraction (soil venting) has been demonstrated to be a successful and cost‐effective remediation technology for removing VOCs from the vadose (unsaturated) zone. However, in many cases, seasonal water table fluctuations, drawdown associated with pump‐and‐treat remediation techniques, and spills involving dense, non‐aqueous phase liquids (DNAPLS) create contaminated soil below the water table. Vapor extraction alone is not considered to be an optimal remediation technology to address this type of contamination.An innovative approach to saturated zone remediation is the use of sparging (injection) wells to inject a hydrocarbon‐free gaseous medium (typically air) into the saturated zone below the areas of contamination. The contaminants dissolved in the ground water and sorbed onto soil particles partition into the advective air phase, effectively simulating an in situ air‐stripping system. The stripped contaminants are transported in the gas phase to the vadose zone, within the radius of influence of a vapor extraction and vapor treatment system.In situ air sparging is a complex multifluid phase process, which has been applied successfully in Europe since the mid‐1980s. To date, site‐specific pilot tests have been used to design air‐sparging systems. Research is currently underway to develop better engineering design methodologies for the process. Major design parameters to be considered include contaminant type, gas injection pressures and flow rates, site geology, bubble size, injection interval (areal and vertical) and the equipment specifications. Correct design and operation of this technology has been demonstrated to achieve ground water cleanup of VOC contamination to low part‐per‐billion levels.
Case Histories of Shallow Time Domain Electromagnetics in Environmental Site Assessment
Authors: Hoekstra Pieter , Lahti Raye , Hild Jim , Bates C. Richard , Phillips David 
Published: February 2007

AbstractTime domain electromagnetic (TDEM) soundings were utilized in site assessment studies for the purpose of accomplishing two objectives: (1) measuring the migration of brines from oil and gas field evaporation pits, and (2) mapping the continuity of clay strata. Both case histories are representative of common objectives in site assessment. The data for both examples were analyzed by one‐dimensional ridge regression inversions.Both case histories illustrate that TDEM is an effective method for determining the lateral and vertical resistivity distribution (geoelectric section) of the subsurface in the depth range from about 5 m to 100 m, and it is known from other investigations that depths of investigations up to 2500 m can be achieved with TDEM.Frequently, the lateral extent of contaminant plumes emanating from localized sources are of limited areal extent. The case history involving the use of TDEM to map a brine plume shows that a TDEM measurement has a relatively small zone of influence, so that meaningful information about the lateral and vertical extent of the plume can be obtained. Both case histories demonstrate the ability of TDEM to determine geoelectric sections below layers of low resistivity.
Evaluation of Visual Methods to Detect NAPL in Soil and Water
Authors: Cohen Robert M. , Bryda Anthony P. , Shaw Scott T. , Spalding Charles P. 
Published: February 2007

AbstractNon‐aqueous phase liquids (NAPLs), such as chlorinated solvents and petroleum products, are present in the subsurface at numerous contamination sites in North America. Determination of NAPL presence should be an early investigation goal to guide site characterization and control efforts. Indirect methods for assessing NAPL presence rely on comparing measured chemical concentrations to effective solubility limits for ground water and to calculated equilibrium partitioning concentrations for soil. Under ideal conditions, NAPL presence can be identified by visual examination of soil or ground water samples. Direct visual detection may be difficult, however, where the NAPL is clear and colorless, present at low saturation, or distributed heterogeneously. There appears to be little documentation of practical, simple methods for direct identification of NAPL in soil or water.For this study, a series of experiments was conducted to test the hypothesis that simple and inexpensive methods can be used to visually identify clear, colorless NAPL in soil and water samples. Specific methods evaluated include direct visual examination, ultraviolet (UV) fluorescence analysis, a soil‐water shake test, adding hydrophobic dye to the shake test, and centrifugation. Additionally, the utility of organic vapor analysis was examined as an NAPL screening tool.Of the methods investigated, the hydrophobic dye methods, followed by UV fluorescence, offer the most simple, practical, and effective means for direct visual identification of clear, colorless NAPL in contaminated soil samples. These methods can be utilized in the field or in a lab with minimal time and material expense. For volatile NAPLs, analysis of organic vapors in soil sample headspace can be used to screen samples for further examination and, possibly, to infer NAPL presence. The NAPL in water experiments demonstrate that very small quantities of clear, colorless NAPL in water can be quickly identified by mixing in a tiny amount of hydrophobic dye.
Comparison of Downhole and Surface Sampling for the Determination of Volatile Organic Compounds (VOCs) in Ground Water
Authors: Rosen Michael E. , Pankow James F. , Gibs Jacob , Imbrigiotta Thomas E. 
Published: February 2007

AbstractThe relative precision and accuracy of sampling and analysis methods for the determination of trace concentrations of volatile organic compounds (VOCs) in ground water were compared. Samples were collected from a well containing nanogram‐per‐liter (ng/L) to microgram‐per‐liter (μg/L) levels of VOCs. A Keck helical rotor submersible pump was used to collect samples at the surface for analysis by purge and trap (P&T) and for analysis by adsorption/thermal desorption (ATD). Downhole samples were collected by passing water through an ATD cartridge. Although slight spontaneous bubble outgassing occurred when the water was brought to the surface, the relative precisions and comparabilities of the surface and downhole methods were generally found to be equivalent from a statistical point of view. A main conclusion of this study is that bringing sample water to the surface for placement in VOC vials (and subsequent analysis by P&T) can be done reliably under many circumstances. However, care must still be taken to prevent adsorption losses and cross contamination. Samples subject to strong bubble outgassing will need to be handled in a special fashion (e.g., by downhole ATD) to minimize volatilization losses. Additionally, the higher sensitivity of the ATD method allows lower detection limits than are possible with P&T. For example, several compounds present at the ng/L level could be determined with confidence by ATD, but not by P&T.
Organic Halogen Group Parameters as Indicators of Ground Water Contamination
Authors: Grøn Christian 
Published: February 2007

AbstractA regional survey of Danish ground water demonstrated the presence of adsorbable organic halogens (AOX) in almost all of 142 wells (99 percent). Generally, the presence of AOX was not related to point or non‐point source contamination with halogenated organics. However, the AOX concentrations varied with the geology of the aquifers. Extractable organic halogens (EOX) and volatile organic halogens (VOX) were far less prevalent (detected in 4 percent of sampled wells) and the detection could, in most cases, be explained by contamination or chlorination of the wells. The VOX concentrations corresponded to the concentrations of identified, volatile contaminants. The study demonstrates the presence of a natural background level of AOX in the investigated aquifers. This must be considered in the interpretation of AOX results as an indicator of ground water contamination with haloorganics. Similar background levels of EOX or VOX were not delected.
Sampling of VOCs with the BAT Ground Water Sampling System
Authors: Mines Barry S. , Davidson John L. , Bloomquist David , Stauffer Thomas B. 
Published: February 2007

AbstractIn the BAT ground water sampling system, a stainless steel probe with a porous filter element is pushed vertically to the desired sampling depth. An evacuated glass sampling tube is then lowered down the penetration rods where it makes contact with the filter via a hypodermic needle and draws a pore fluid sample.An investigation of the system was carried out at a number of sites contaminated by leaking underground gasoline storage tanks. Ground water samples obtained using the BAT system and adjacent monitoring wells were analyzed for volatile organic compounds (VOCs).Because the BAT system is an in situ penetration device with a small filter length, it is possible to determine variations in contaminant concentration with depth. BAT samples in general exhibited higher recovery of VOCs than did bailer samples from adjacent monitoring wells screened over large intervals.Much higher levels of VOCs were recovered when the probe was used with its 316 stainless steel filter than when using the high‐density polyethylene (HDPE) filter. Significant sorption apparently occurred on the latter filter.Because the BAT sample tubes are sealed and remain a closed system, the in situ water pressure is maintained. No significant loss of VOCs was found in sampling tubes containing headspace. Samples from the upper tube in the cascaded setup with headspace recovered levels of VOCs as high, or in a few cases higher, than the lower, no‐headspace tubes.
Hydrocarbon Vapor Diffusion in Intact Core Sleeves
Authors: Ostendorf David W. , Moyer Ellen E. , Xie Yuefeng , Rajan R. V. 
Published: February 2007

AbstractThe diffusion of 2,2,4‐trimethylpentane (TMP) and 2,2,5‐trimethylhexane (TMH) vapors put of residually contaminated sandy soil from the U.S. Environmental Protection Agency (EPA) field research site at Traverse City, Michigan, was measured and modeled. The headspace of an intact core sleeve sample was swept with nitrogen gas to simulate the diffusive release of hydrocarbon vapors from residual aviation gasoline in and immediately above the capillary fringe to a soil‐venting air flow in the unsaturated zone. The resulting steady‐state profile was modeled using existing diffusivity and air porosity estimates in a balance of diffusive flux and a first order source term. The source strength, which was calibrated with the observed flux of 2,2,4‐TMP leaving the sleeve, varied with the residual gasoline remaining in the core, but was independent of the headspace sweep flow rate. This finding suggested that lower soil‐venting air flow rates were in principle as effective as higher air flow rates in venting LNAPL vapors from contaminated soils. The saturated vapor concentration ratio of 2,2,4‐TMP to 2,2,5‐TMH decreased from 6.6 to 3.5 over the duration of the experiments in an expression of distillation effects. The vertical profile model was tested against sample port data in four separate experiments for both species, yielding mean errors ranging from 0 to—24 percent in magnitude.