bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Situ Measurement and Numerical Simulation of Oxygen Limited Biotransformation
Authors: Borden Robert C. , Lee Michael D. , Thomas J. Michele , Bedient Philip B. , Ward C. Herbert 
Published: February 2007

AbstractEnhanced subsurface biorestoration is rapidly becoming recognized as a valuable tool for the restoration of hydrocarbon‐contaminated aquifers and sediments. Previous field and laboratory studies at a former wood creosoting facility near Conroe, Texas, have indicated that insufficient oxygen is the primary factor limiting the biotransformation of polynuclear aromatics (PNAs) in sediments and ground water at this site. A series of laboratory experiments and field push‐pull injection tests were performed as part of this project to: (1) study the effect of low oxygen concentrations on the biotransformation of PNAs; (2) identify the minimum concentration of PNAs that could be achieved through the addition of oxygen alone; (3) confirm that enhanced subsurface biorestoration is feasible at this site; and (4) test an existing numerical model of the biotransformation process (BIOPLUME). The laboratory studies demonstrated that biotransformation of the PNAs was not inhibited at dissolved oxygen concentrations as low as 0.7 mg/L although this work did suggest that there may be a minimum PNA concentration of 30 to 70 μg/L total PNAs below which biotransformation was inhibited. The field push‐pull tests confirmed that addition of oxygen was effective in enhancing the subsurface biodegradation of the PNAs. The minimum concentration achieved using oxygen alone was approximately 60 μg/L total PNAs. Minimal biotransformation of these compounds was observed without oxygen addition. The numerical model BIOPLUME was tested against monitoring data from the field experiments and appears to provide a good approximation of the biodegradation process.
Remediation of Contaminated Ground Water Using Biological Techniques
Authors: Flathman Paul E. , Jerger Douglas E. , Bottomley Lucy S. 
Published: February 2007

AbstractOn‐site biological cleanup following spills of biodegradable hazardous organic compounds in lagoon, soil, and ground water environments is a cost‐effective technique when proper engineering controls are applied. Biodegradation of hazardous organic contaminants by microorganisms minimizes liability by converting toxic reactants into harmless end products.Three case histories presented in this paper detail:• Bench‐scale evaluation of the potential for biological remediation in the spill site matrix• Field implementation of biological treatment techniques.Cost‐effectiveness, minimal disturbance to existing operations, and on‐site destruction of spilled contaminants are several of the advantages identified for implementing biodegradation as a technique for spill cleanup and environmental restoration.
Volume Determination and Recoverability of Free Hydrocarbon
Authors: Testa Stephen M. , Paczkowski Michael T. 
Published: February 2007

AbstractFree‐phase hydrocarbon product occurs as perched zones on the capillary fringe beneath numerous petroleum‐handling facilities. Under such site conditions, too much emphasis is placed on the time‐frame required for remediation by federal, state, and local regulators, notably in respect to monitoring the efficiency and effectiveness of the respective remediation program. The time required for remediation within the scope of present‐day technology is a calculated or educated guess at best. Typically, remediation duration is determined by a number of estimates. These estimates have innate compounding errors. Areas of estimation include physical measurement accuracy; “true” vs. apparent thickness; validity of bail‐down testing; extrapolation of free hydrocarbon product thicknesses between monitoring points; contouring of thickness maps, extrapolation of geologic information, planimetering, and estimation of porosity; specific yield and retention; all of which are key factors used in ultimately determining the volume of free hydrocarbon product in place.Once an initial estimated volume is determined, pilot testing of a recovery system should commence to determine recovery rates.Factors that will affect recovery rates include the areal distribution and geometry of the hydrocarbon pool, type, and number of recovery system(s) selected, and the performance or efficiency of these systems with time. Effectiveness of the recovery program is thus best estimated based on barrels recovered to date divided by the total volume of barrels that are considered recoverable.Remediation time frame at petroleum hydrocarbon recovery sites can be estimated. However, regulators at all levels need to be aware of the large number of compounding errors associated with these calculations. Estimations should be used with extreme caution, because they are usually overestimations. Once a realistic time frame for remediation is mutually agreed upon, it should be clearly understood that it is flexible. It is recommended that a range be initially determined and that as a project progresses and new data are introduced, the remediation time frame be adjusted accordingly.
Flush‐Joint Threads Find a Home
Authors: Foster Shawn 
Published: February 2007

AbstractWith the rapid growth of PVC in the well casing and screen market, many different applications and methods of use have surfaced. One major method of fastening or joining thermoplastic well casing is the flush‐joint thread. Widespread use of flush‐joint threads on Schedule 40 and Schedule 80 pipe has caused concern about the physical strength and hydrostatic integrity of these threads. These concerns are magnified when one discovers the multitude of different manufacturers, each with his own thread design. There has, however, been a solution: Committee F17 of ASTM has passed a change in the Standard F480, which is now: ASTM F480–88A Standard Specification for Thermoplastic Well Casing and Couplings Made In Standard Dimension Ratios (SDR), Schedule 40 and Schedule 80. This change partially consists of incorporating specifications for flush‐joint threads in Schedule 40 and Schedule 80 casing, in sizes ± inch to 16 inch in Schedule 80 and 2 inch to 16 inch in Schedule 40. This long overdue standard now ensures field thread compatibility with all pipe specified with this standard. It also requires manufacturers to cut a functional and reliable thread.Extensive testing has been done to determine the physical properties of the specified thread. The three tests that help the purchaser determine the working parameters of this flush‐joint thread include:1. Tensile test of the threaded joint2. Internal hydrostatic pressure test3. External hydrostatic pressure test.Using ASTM guidelines test methods were developed for testing this thread. Results show that the new thread specification in F480 is a valid and functional design.
Equipment Decontamination Procedures for Ground Water and Vadose Zone Monitoring Programs: Status and Prospects
Authors: Mickam James T. , Bellandi Robert , Tifft Edwin C. 
Published: February 2007

AbstractA major portion of the work effort and, therefore, the money spent during investigations of ground water and the vadose zone at hazardous waste sites is associated with collecting chemical data. To that end, effective decontamination of reusable drilling equipment, sampling apparatus, and tools is critical to the credibility of chemical data. Samples representative of the site under study are essential.Several state and federal regulatory agencies have established guidelines for procedures that should be considered when developing decontamination protocols. These agencies were contacted and asked to furnish copies of their decontamination guidelines. The information received was reviewed, and comparisons were made to assess the status of standards of decontamination practices for ground water and vadose zone monitoring programs at hazardous waste sites. Summaries of a variety of decontamination protocols were prepared. From this review, it is apparent that there is a need to standardize, to the extent possible, procedures for the field decontamination of equipment.Two ASTM Subcommittees, D18.14 on Waste Management and D18.21 on Ground Water and Vadose Zone Monitoring, are currently working on developing standards for decontamination procedures. They, in cooperation with state and federal agencies and other interested technical groups, will develop standards for the field decontamination of equipment used to study ground water and the vadose zone.
Using Soil and Meteorologic Data Bases in Unsaturated Zone Modeling of Pesticides
Authors: Carsel Robert F. , Jones Russell L. 
Published: February 2007

AbstractVarious types of models are being used to evaluate pesticide transport and transformation in the unsaturated zone. Model predictions can be used, for example, to develop alternative agricultural management strategies for pesticide use. However, intensive data requirements for transient models sometimes deter their use. Site‐specific measurements are preferred, but existing data bases can be used as a source of required model parameters, especially weather and soil characteristics. These existing data bases make possible the use of models to predict leaching potential in a wide variety of environments.
Ground Water Monitoring at Wellhead Protection Areas
Authors: Meyer Philip D. 
Published: February 2007

AbstractWellhead protection programs implemented to this date have not, in general, included a comprehensive ground water monitoring strategy. This is due both to the relatively recent introduction of the wellhead protection concept into the ground water field and also to the complexity of the monitoring problem. A well‐planned monitoring program, however, can contribute significantly to the success of a wellhead protection program. The elements of wellhead protection, important from a monitoring perspective, are the management objectives, the types of potential contaminant sources, and the locations of those sources with respect to the wellhead protection area boundary. General monitoring strategies applicable to wellhead protection are derived from the relationships between these elements.
A National Evaluation of the Leaching Potential of Aldicarb Part 2. An Evaluation of Ground Water Monitoring Data
Authors: Lorber Matthew N. , Cohen Stuart Z. , DeBuchananne George D. 
Published: February 2007

AbstractAldicarb was first found in ground water in Suffolk County, New York, in the late 1970s associated with its use on potatoes. Since then, there has been a substantial amount of monitoring associated with aldicarb use on potatoes nationally and on citrus in Florida. A recent monitoring study by the registrant of aldicarb supplemented limited monitoring data on other critical aldicarb uses including cotton and peanuts. This paper reports on monitoring programs and studies encompassing more than 50,000 ground water samples, of which approximately 32 percent are positive and 13 percent are above EPA's Health Advisory Level of 10 ppb. These monitoring results were used in an integrated assessment to identify areas of the United States where aldicarb is likely to leach to ground water (Lorber et al. 1989). Positive findings are reported for 61 counties in 19 states, and findings above 10 ppb are reported for 31 counties in 11 states. Monitoring data associated with the use of aldicarb on potatoes in the Northeast and upper Midwest (Wisconsin, Virginia, New York, Massachusetts, Rhode Island, Maine) are extensive and demonstrate the potential for aldicarb to impact ground water near potato‐use sites. In contrast, monitoring associated with potato use in the Northwest (Idaho, Oregon, Washington) and a three‐county potato‐growing area in Florida have shown negative results. Sampling near cotton use in the South and Southwest (Georgia, Alabama, Tennessee, Arkansa, Louisiana, Texas, Arizona) showed negative findings, while a small number of positives were found in North Carolina and South Carolina. Limited monitoring associated with peanuts showed negative results in the South (North Carolina, South Carolina, Georgia), although sampling beneath a field research site in Georgia showed trace positives. Sampling from monitoring wells established in the shallow water table aquifer beneath and downgradient from citrus use sites in Florida showed both a high frequency and high concentrations of aldicarb, with one finding above 1000 ppb and numerous findings greater than 100 ppb. However, in three separate efforts encompassing more than 1200 samples from roughly the same number of domestic drinking water wells located near citrus fields with histories of aldicarb usage, only 2 percent contained residues of aldicarb. No positives were found in 800 samples from roughly the same number of deep public drinking water wells in counties with high citrus acreage and aldicarb usage. This paper also reports on monitoring associated with lily bulb use in northern California, fernery use in Florida, sugar beet use in Montana, and smaller exploratory efforts in several other states.
Accounting for Temporal Variations in Large‐Scale Retrospective Studies of Agricultural Chemicals in Ground Water
Authors: Liddle Susan K. , Whitmore Roy W. , Mason Robert E. , Alexander W. Joseph , Holden Larry R. 
Published: February 2007

AbstractGround water studies that require long data collection periods may be affected by temporal changes in ground water chemistry. Seasonal fluctuations in ground water chemistry are particularly apparent in shallow aquifers. Of specific interest is the inclusion of temporal variability in the design of statistical surveys of agricultural chemicals in well water. Statistical treatment of temporal variability involves selecting a probability sample from temporal units. The selection strategy may include repeating the same spatial units in each temporal stratum or choosing an independent sample of spatial units for each temporal stratum. The appropriate strategy depends on the specific study objectives. Failure to account for temporal variability may compromise the validity of study conclusions. An example of a large‐scale retrospective survey designed to estimate temporal averages of water quality across all wells is presented.
Pesticide Contamination of Ground Water Artificially Recharged by Farmland Runoff
Authors: Exner Mary E. 
Published: February 2007

AbstractAtrazine, cyanazine, alachlor, and metolachlor in the surface water of a recharge structure, which impounds runoff from row‐cropped farmland in Nebraska, are transported with seepage to the shallow ground water flow system and to the locally confined regional aquifer. All wells in the shallow flow system and all those in the regional flow system impacted by seepage from the structure had detectable concentrations of at least one of the four pesticides.The detectable concentrations of cyanzine, alachlor, and metolachlor in the two flow systems ranged from 0.1 to 0.9 ppb. These concentrations were an order of magnitude lower than those in the surface water. Concentrations in the regional aquifer clustered at the lower end of this concentration range. These three pesticides were not detected in the baseline study of the regional aquifer.Unlike alachlor, cyanzine, and metolachlor, atrazine was always present in the wells impacted by seepage from the recharge structure. In the shallow flow system, concentrations ranged from 0.3 to 8.8 ppb and from 0.1 to 2.5 ppb in the regional aquifer. The average of the detectable atrazine concentrations in the baseline study was 0.04 ± 0.05 ppb.
A Supplementary Method for Assessing the Reliability of Fluids Sampled from Deep Aquifers
Authors: Nativ Ronit 
Published: February 2007

AbstractIn deep aquifers, temperatures of formation fluids recovered during drill‐stem tests were usually higher than regular bottom‐hole temperatures recorded at the same borehole and interval. Wherever the opposite was observed, the sampled formation fluids were diluted with mud filtrate or cushion water. Temperature measurements are a useful criterion for differentiating between representative and contaminated formation‐fluid samples.
Development of a Standard, Pure‐Compound Base Gasoline Mixture for Use as a Reference in Field and Laboratory Experiments
Authors: Kreamer David K. , Stetzenbach Klaus J. 
Published: February 2007

AbstractIn recent years, leaking underground petroleum storage tanks have become a major environmental concern. Federal, state, and local agencies are making efforts to assess, control, and remediate petroleum product leaks. Because petroleum products are mixtures of many compounds and the composition frequently changes, there exists a need for a standard reference mixture that can be used as a basis for comparison in the study of fluid transport properties in porous media and to evaluate leak detection devices. The proposed standard presented here retains the most important liquid and vapor properties (such as vapor density, air diffusion coefficient, and basic chemical constituency) of gasoline mixtures. It also reduces the complexity of the mixture to make it an acceptable standard for routine use in laboratory and field experiments.
Influence of Casing Materials on Trace‐Level Chemicals in Well Water
Authors: Parker Louise V. , Hewitt Alan D. , Jenkins Thomas F. 
Published: February 2007

AbstractFour well casing materials — polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), and stainless steel 304 (SS 304) and 316 (SS 316) — were examined to determine their suitability for monitoring inorganic and organic constituents in well water.The inorganic study used a factorial design to test the effect of concentration of mixed metals (arsenic [As], chromium [Cr], lead [Pb], and cadmium [Cd]), pH, and organic carbon. Sample times were 0.5, 4, 8, 24, and 72 hours. Except for slow loss of Pb, PTFE well casings had no significant effect on the concentration of metals in solution. For the other casings, changes in analyte concentration often exceeded 10 percent in eight hours or less and, thus, could bias analyses of samples taken from wells constructed with these materials. Specifically, PVC casings sorbed Pb and leached Cd; SS 316 casings sorbed As and Pb and leached Cd; and SS 304 casings sorbed As, Cr, and Pb and leached Cd. Both stainless steel casing materials showed markedly poorer performance than the PVC casings.The well casings were also tested for sorption/desorption of 10 organic substances from the following classes: chlorinated alkehes, chlorinated aromatics, nitroaromatics and nitramines. Sample times were 0, 1, 8, 24, and 72 hours, seven days, and six weeks. There were no detectable losses of analytes in any of the sample solutions containing stainless steel well casings. Significant loss of some analytes was observed in sample solutions containing plastic casings, although losses were always more rapid with the PTFE casings than with PVC. Chlorinated organic substances were lost most rapidly. For samples containing PTFE casings, losses of some of these compounds were rapid enough (>10 percent in eight hours) to be of concern for ground water monitoring. Losses of hydrophobic organic constituents in samples containing PTFE casings were correlated with the compound's octanol/water partition coefficient.
Application of Marine Seismic Profiling to a Ground Water Contamination Study, Aberdeen Proving Ground, Maryland
Authors: Hughes W. Brian 
Published: February 2007

AbstractContinuous high‐frequency marine seismic profiling was used to define the extent of geologic units in the offshore areas of J‐Field, Aberdeen Proving Ground, Maryland, during March and April of 1988. J‐Field is an area that was used by the U.S. Army for disposal of chemical warfare agents, munitions, and organic solvents from the 1950s through the 1970s. A major concern at this site is the subsurface migration of hazardous wastes into offshore areas and eventually into the Chesapeake Bay. A 150‐foot (45.7 meter) deep paleochannel containing Pleistocene age fluvial and estuarine sediments was identified from boreholes constructed onshore. The paleochannel sediments consist of three lithic units. From bottom to top these units consist of gravel and sand, massive silty and sandy clay, and interbedded sand and clay. The seismic profiles were used to identify the extent of these units and map them in offshore areas. An accurate knowledge of the distribution of the geologic units in onshore and offshore areas is important to the investigation because the coarse‐grained paleochannel sediments may provide a preferential flow path for contaminated ground water and the fine‐grained sediments may impede the movement of contaminants into deeper aquifers.
Cone Penetrometer Tests and HydroPunch® Sampling: A Screening Technique for Plume Definition
Authors: Smolley Mark , Kappmeyer Janet C. 
Published: February 2007

AbstractCone penetrometer tests and HydroPunch® sampling were used to define the extent of volatile organic compounds in ground water. The investigation indicated that the combination of these techniques is effective for obtaining ground water samples for preliminary plume definition. HydroPunch samples can be collected in unconsolidated sediments and the analytical results obtained from these samples are comparable to those obtained from adjacent monitoring wells. This sampling method is a rapid and cost‐effective screening technique for characterizing the extent of contaminant plumes in soft sediment environments. Use of this screening technique allowed monitoring wells to be located at the plume boundary, thereby reducing the number of wells installed and the overall cost of the plume definition program.
Field Sampling of Residual Aviation Gasoline in Sandy Soil
Authors: Ostendorf David W. , Leach Lowell E. , Hinlein Erich S. , Xie Yuefeng 
Published: February 2007

AbstractTwo complementary field sampling methods for the determination of residual aviation gasoline content in the contaminated capillary fringe of a fine, uniform, sandy soil were investigated. The first method featured field extrusion of core barrels into pint‐size Mason jars, while the second consisted of laboratory partitioning of intact stainless steel core sleeves. The barrel extrusion procedure involved jar headspace sampling in a nitrogen‐filled glove box, which delineated the 0.7m thick residually contaminated interval for subsequent core sleeve withdrawal from adjacent boreholes. Soil samples removed from the Mason jars (in the field) and sleeve segments (in the laboratory) were subjected to methylene chloride extraction and gas chromatographic analysis to compare their aviation gasoline content. The barrel extrusion sampling method yielded a vertical profile with 0.10m resolution over an essentially continuous 5.0m interval from the ground surface to the water table. The sleeve segment alternative yielded a more resolved 0.03m vertical profile over a shorter 0.8m interval through the capillary fringe. The two methods delivered precise estimates of the vertically integrated mass of aviation gasoline at a given horizontal location, and a consistent view of the vertical profile as well. In the latter regard, a 0.2m thick lens of maximum contamination was found in the center of the capillary fringe, where moisture filled all voids smaller than the mean pore size. The maximum peak was resolved by the core sleeve data, but was partially obscured by the barrel extrusion observations, so that replicate barrels or a half‐pint Mason jar size should be considered for data supporting vertical transport analyses in the absence of sleeve partitions.