bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Development and Implementation of a Remedial Investigation Work Plan and Data Management System
Authors: Olson Clifford M. 
Published: February 2007

AbstractThe Pompton Lakes Works is a 580‐acre industrial facility in northern New Jersey that has manufactured explosives for more than 100 years. Waste from these operations was disposed of on‐site and a remedial investigation (RI) was initiated to determine the extent of contamination. A history of waste disposal, completed in 1989, identified 119 potential waste sites that vary in size from point sources to entire manufacturing operations of more than 40 acres. Before RI operations began, three issues had to be addressed. First is the length of the investigation and the need for consistency between the first and the last site investigated, second is the need to eliminate the investigative “stop and go” effects (delays for analysis, drillers, etc.) on the RI operations, and third is to report, in a useful manner, the massive amounts of RI data.The solution to these issues involved the use of a sophisticated database management system developed concurrently with the RI work plan (RIWP) and designed around the RI goals. The RIWP addresses the first issue of consistency with two components, sample rules, and phased sampling. The sample rules dictate the analytes and the sample location (depending on previous results and on the phase). Phased sampling allows for incremental increases in work (depending on previous results) and is divided into two phases, exploratory that confirms the presence of contamination and characterization, with a variable number of rounds, that defines contaminant extent. These components are simple, easily applied, yet infinitely flexible to address changing conditions, and readily adapted to database management.The database management system is the key to controlling a large RI; it eliminates the investigative “stop and go” and the problems associated with massive amounts of data. The system incorporates all investigative information (including digitized maps) into sample plans, chain‐of‐custodies, and reports. The reports may be either concurrent with RI work (i.e., a specific phase or round) or a summary report of the completed investigation at a waste site. The system allows a number of waste sites to be investigated simultaneously so that one person can manage a complex RI with a minimum of personnel, a maximum number of sites (in different phases or rounds), and issue timely reports that are crisp, concise, and informative.Combining development of the RIWP with the database management system not only addressed the investigative aspects but also the operational and the reporting aspects too.
The Occurrence of Appendix IX Organic Constituents in Disposal Site Ground Water
Authors: Plumb R. H. 
Published: February 2007

AbstractMonitoring data from 479 disposal site investigations were used to provide an initial estimate of the occurrence and distribution of 208 Appendix IX organic constituents in ground water. The most prevalent class of contaminants were the volatile organic compounds, which accounted for 84 percent of all the detectable events in the composite data set involving Appendix IX organic constituents. The abundance of the remaining subsets of Appendix IX organic constituents decreased in the following order: base/neutral compounds (8.6 percent), acid extractable compounds (3.5 percent), pesticides (3.0 percent), RCRA pesticides (0.6 percent), and non‐priority pollutants (0.25 percent). A total of 66 Appendix IX organic constituents, including one volatile compound, two pesticides, three base/neutral compounds, and 60 non‐priority pollutant compounds were not detected in any of the waste disposal site ground water monitoring records that were reviewed.The current regulatory requirement to monitor for Appendix IX organic constituents is approximately four times more expensive than monitoring for conventional priority pollutants (volatile, base/neutral, acid extractable, and pesticide compounds). Because the non‐priority pollutant compounds account for an estimated 76 percent of the Appendix IX analytical costs but only 0.25 percent of the detectable events in disposal site ground water, it has been recommended that this class of compounds be deleted from routine monitoring programs. A scaling back of the current requirement to the conventional priority pollutants would still target more than 99 percent of the Appendix IX organic constituent occurrences in ground water and result in an analytical cost savings of approximately $2750 per sample or an estimated $51 million a year without significantly reducing the volume of useful organic monitoring data that would be generated to assess ground water conditions in the vicinity of waste disposal sites.
A Large‐Scale Retrospective Ground Water Monitoring Study for Metolachlor
Authors: Roux Paul H. , Balu K. , Bennett Rodney 
Published: February 2007

AbstractA large‐scale retrospective ground water monitoring study'for metolachlor, 2‐chloro‐N‐(2‐ethyl‐6‐methylphenyl)‐ N‐(2‐methoxy‐l‐methylethyl) acetamide, was conducted. The study consisted of the collection and analysis of ground water samples from 240 existing wells (203 domestic farm wells and 37 monitoring wells) in selected areas of four states: the Dougherty Plains, Georgia; McLean County, Illinois; Floyd and Mitchell counties, Iowa; and the Central Sands area of Wisconsin. These locations were selected on the basis of high metolachlor use and hydrogeological vulnerability.The wells selected were all screened in the uppermost aquifer, were relatively shallow, and were located close to fields where metolachlor has historically been used. Pesticide handling and storage practices on the farms where the wells were located were documented, and wells were selected to avoid obvious point sources. The wells selected for monitoring included drinking water, irrigation and monitoring wells. Monitoring was at quarterly intervals for a one‐year period.Metolachlor was detected in 89 of 920 samples (9.7 percent) from 39 of 240 wells (16.3 percent) with a screening level (quantitation level) of 0.1 ppb. Ten out of 240 wells sampled (4.2 percent) showed detections in all sampling rounds.Of the samples analyzed, 5.1 percent had detections in the range between 0.1 and 0.5 ppb. Thus, non‐detections plus detections below 0.5 ppb accounted for 95.4 percent of all samples, and detections below 0.5 ppb represented more than half of all the detections found in the study (47 out of 89 detections). In the 31 samples where metolachlor was detected above 1.0 ppb, every detection could be related to a known or suspected point source.Based on the frequency and magnitude of metolachlor detections in this study, there appears to be no significant measurable field leaching of metolachlor to ground water under conditions of high product use and high ground water vulnerability. Instead, measurable detections of metolachlor, particularly those exceeding 1.0 ppb, appear to be associated with point sources.
Estimating Geohydrologic Properties from Borehole‐Geophysical Logs
Authors: Jorgensen Donald G. 
Published: February 2007

AbstractBorehole‐geophysical logs can be used to estimate geohydrologic properties based on in situ measurement of rock and water properties. Estimates of properties of both formation and water, such as coefficient of diffusion, formation factor, cementation exponent, hydraulic conductivity, irreducible water content and specific yield can be assessed from borehole‐geophysical data and selected algorithms and graphs.Water properties, such as resistivity, sodium chloride concentration, viscosity and density, can also be estimated using data from borehole‐geophysical logs. Water resistivity using the spontaneous‐potential method can be estimated if an empirical correction for fresh water is applied.Estimates of formation properties, such as porosity and permeability, can also be made using borehole‐geophysical data.
Laboratory Demonstration of Hydrocarbon Migration in the Vadose Zone: Effectiveness of the U‐Tube Design for Underground Storage Tank Leak Detection Monitoring
Authors: Springer David S. , Keller Edward A. , Everett Lome G. , Eccles Lawrence A. 
Published: February 2007

AbstractThe experimental results derived from a laboratory model of gasoline migration from a simulated leaking underground storage tank (UST) demonstrate that the direction of migration through the simulated fill material is essentially straight down. Consequently, the U‐tube design for leak detection monitoring of USTs has limited utility because that design relies on the assumption that the path of migration of the leaked fluids will follow the surface of the tank to the bottom and be intercepted by the U‐tube below.
Survey of Rural Wells in Missouri for Pesticides and Nitrate
Authors: Sievers Dennis M. , Fulhage Charles D. 
Published: February 2007

AbstractTwo hundred and one rural wells were sampled in eight agricultural areas of Missouri. Samples were analyzed for 25 pesticides and nitrate. Forty‐three percent of the wells sampled had at least one pesticide detection. Thirteen percent of the wells had at least one detection ≧ 1 ppb and these concentrations were confirmed. Only one well exceeded U.S. EPA Health Advisory levels. Twenty‐two percent of the wells exceeded the U.S. EPA Drinking Water Standard for nitrate. Pesticide detections were most strongly correlated to well depth. Nitrate levels were primarily related to well depth, well construction methods, and well siting.
Procedures for Sampling Deep Subsurface Microbial Communities in Unconsolidated Sediments
Authors: Russell Brent F. , Phelps Tommy J. , Griffin William T. , Sargent Kenneth A. 
Published: February 2007

AbstractA corehole sampling project utilizing a wireline coring system provided sediment samples for microbiological characterization from deep unconsolidated sediments. Sampling tools were developed or modified to minimize contamination during sample acquisition and to facilitate stringent decontamination requirements. Quality assurance procedures, including the use of tracers, were implemented to minimize and quantify contamination from drilling hardware, drilling fluids and sample processing. Tracers included microspheres, potassium bromide, rhodamine dye, and perfluorocarbons, which enabled the detection and measurement of 1mg of drilling fluid per kg of sediment. In addition, sample processing was performed on‐site in an anaerobic chamber to prevent exposure of the subsurface materials to atmospheric oxygen concentrations. Sediment samples were then disbursed to investigators at National Laboratories and universities funded through the Department of Energy Subsurface Science Microbiology Program for microbiological characterization. Results of these efforts demonstrated that representative subsurface samples were collected and disbursed.
Estimation of the Probability of Exceedance of Contaminant Concentrations
Authors: McBean Edward A. , Rovers Frank A. 
Published: February 2007

AbstractSeveral alternative probability distributions for estimating the probability of exceedance of contaminant concentrations are examined for their appropriateness for developing inputs to risk assessments. The rationale is provided for using the log Pearson Type III distribution, a three‐parameter model, for estimation of the exceedance probabilities.
Spatial Moment Analysis for Mass Balance Calculations and Tracking Movement of a Subsurface Hydrocarbon Mound
Authors: Knox Robert C. 
Published: February 2007

AbstractLeaking underground storage tanks are a proven source of subsurface hydrocarbon contamination. An improbable leak scenario supported by anomalous field data formed the basis of a major lawsuit filed against a tank installer. A simplified hydrocarbon mound migration model, coupled with basic mass balance calculations, showed the field data to be inconsistent with the purported leak scenario, and showed monitoring well tampering to be the source of hydrocarbon contamination. The method described is a simple yet efficient means of developing hydrocarbon mass estimates and mound migration projections. These values can also be valuable in siting injection/extraction locations and developing integrated in situ remediation technologies.
In Situ Electromigration as a Method for Removing Sulfate, Metals, and Other Contaminants from Ground Water
Authors: Runnells Donald D. , Wahli Catherine 
Published: February 2007

AbstractElectromigration is proposed as an in situ method for preconcentrating contaminants in ground water prior to pumping and treating. In earlier investigations by the senior author and co‐workers, it was found that Cu in synthetic ground water migrated strongly to a Pt cathode and plated out as metallic copper. In the present study, carbon electrodes were inserted into a laboratory column of fine quartz sand that was saturated with a lower concentration of CuSO4 solution. A fixed potential of 2.5 V was applied, causing dissolved Cu and SO4 to accumulate strongly at the cathode and anode, respectively. Only minor plating‐out of Cu took place on the carbon electrodes. In addition to the use of carbon electrodes, the present research also investigated the effects of a lower concentration of metal, accumulation of SO4 adjacent to the anodes, adsorption of Cu on the sand, and competition by moving ground water.At an imposed voltage of 2.5 V and in the presence of 65 mg/L of dissolved Cu and 96 mg/L of SO4 (0.001 M CuSO4 solution), electrolysis of water caused large changes in the pH and speciation of the aqueous components, as well as precipitation of solid Cu‐hydroxides. Significant retardation of Cu occurred in the presence of ground water flowing at an average intergranular velocity of 0.2 m/day, but only minor retardation at water velocities of 1.9 and 2.9 m/day.Sulfate tends to migrate strongly to the anodes, suggesting that in situ electromigration may offer a useful new method for preconcentrating such highly soluble ions as SO4, NO3, and CI that are difficult to remove by conventional pump‐and‐treat methods. A number of potential problems exist that should be addressed in a field test.
Sampling for Purgeable Organic Compounds Using Positive‐Displacement Piston and Centrifugal Submersible Pumps: A Comparative Study
Authors: Knobel LeRoy L. , Mann Larry J. 
Published: February 2007

AbstractPositive‐displacement piston pumps that minimize sample agitation have no apparent advantage over centrifugal submersible pumps when used to collect ground water samples for analysis of low concentrations of purge‐able organic compounds. Analytical uncertainties inherent in laboratory environments appear to influence analytical results of low‐concentration purgeable organic compound samples more than either pump type or sampling team. Centrifugal submersible pumps are at least equally efficient as positive‐displacement piston pumps in the recovery of carbon tetrachloride, 1,1,1‐trichloroethane, trichloroethylene, and chloroform after sampling and analytical influences are made constant.
Casing Leakage in Monitoring Wells: Detection, Confirmation, and Prevention
Authors: van der Kamp G. , Keller C.K. 
Published: February 2007

AbstractA small but significant proportion of all existing monitoring wells may be affected by leakage through the casing, usually at joints. Casing leakage can render data obtained from a monitoring well unreliable. Anomalous water level, water quality, or isotope data from a particular well are an indication of possible leakage. The occurrence of a casing leak can be confirmed by means of a pressure test using water. The magnitude of the leakage flow can be estimated from the pressure test or from the observed head anomaly. Casing leaks can be largely prevented with adequate care during monitoring well installation, but the possibility that data may be affected by casing leaks should always be taken into account during hydrogeological investigations.
Dynamic Study of Common Well Screen Materials
Authors: Hewitt Alan D. 
Published: February 2007

AbstractExperiments simulating the dynamics of compliance sampling via a monitoring well were performed to assess the effects of common well screen materials (rigid polyvinyl chloride, polytetrafluoroethylene, stainless steel 304. and stainless steel 316) on several metals and tri‐ chloroethylene (TCE) in ground water. This was achieved by using a continuous flow‐through chamber system capable of exposing monitoring well screens to ground water for periods ranging from 0.25 to 8 hours. The findings of this study are more representative than static laboratory experiments for assessing the potential effects well casing materials have on ground water samples. Under dynamic flow conditions stainless steel 304 and 316 screens were found to influence solution concentrations of Pb, Cd, Cr, Ni, and Fe, while ground water TCE concentrations were not affected by any of the materials tested.
Field Trapping of Subsurface Vapor Phase Petroleum Hydrocarbons
Authors: Moyer Ellen E. , Ostendorf David W. , Kampbell Don H. , Xie Yuefeng 
Published: February 2007

AbstractSoil gas samples from intact soil cores were collected on adsorbents at a field site, then thermally desorbed and analyzed by laboratory gas chromatography (GC). Vertical concentration profiles of predominant vapor phase petroleum hydrocarbons under ambient conditions were obtained for the zone directly above the capillary fringe. Water and residual phase weathered aviation gasoline were present in this region of the profile.The sampling, trapping, and GC methodology was effective in most respects. Reproducibility, trapping, and desorption efficiency were generally satisfactory, and different sorbent tubes gave similar results. A minor shortcoming of the method occurred with the most volatile compound, 2,3‐dimcthylbutane, which was poorly retained during several weeks of storage lime and was also poorly desorbed.Vapor phase concentrations of predominant hydrocarbon compounds all increased with depth at one sampling location. At a more highly contaminated location, concentrations of highly volatile compounds increased with depth while concentrations of less volatile compounds remained constant or decreased, possibly indicating distillation effects. Scatier in the data was attributed to heterogeneities in water and residual phase distribution.
Contaminant Spread and Flushing in Fractured Rocks Near Oak Ridge, Tennessee
Authors: Shevenell L.A. , Moore G.K. , Dreier R.B. 
Published: February 2007

AbstractLiquid wastes, including metals dissolved in nitric acid, were discharged into the S‐3 Ponds from 1951 to 1983. During this period, contaminants in ground water spread along shallow fracture flow paths toward nearby streams. Also, a high concentration of nitrate in one well at a depth of 110 to 240 in shows that some contaminants may have moved downdip because of differences in fluid density. Neutralization of the ponds in June 1983 caused a dramatic decrease in the contaminant concentrations of Bear Creek about three months later. Since then, the contaminant concentrations of Bear Creek have decreased at a first‐order exponential rate. This average rate, which is the same for both more reactive and less reactive constituents, can be interpreted to show that the contaminant reservoir consists of the unfractured rock matrix.Flushing caused by the natural recharge and discharge of ground water is occurring at all locations, but contaminant concentrations are controlled by the relative rates of molecular diffusion from the rock matrix and advection along the fracture flow paths. Hushing has thus been most effective near the water table. If the exponential decrease in contaminant concentrations continues, water in Bear Creek will meet drinking water standards by 2012: regardless of any remedial action, contaminants will remain in the rocks for many years.
A Practical Approach to Evaluating Natural Attenuation of Contaminants in Ground Water
Authors: McAllister P.M. , Chiang C.Y. 
Published: February 2007

AbstractThe extent of natural attenuation is an important consideration in determining the most appropriate corrective action at sites where ground water quality has been impacted by releases of petroleum hydrocarbons or other chemicals. The objective of this study was to develop a practical approach that would evaluate natural attenuation based on easily obtained field data and field tested indicators of natural attenuation. The primary indicators that can he used to evaluate natural attenuation include plume characteristics and dissolved oxygen levels in ground water. Case studies of actual field sites show that plumes migrate more slowly than expected, reach a steady state, and decrease in extent and concentration when natural attenuation is occurring. Background dissolved oxygen levels greater than 1 to 2 mg/L and an inverse correlation between dissolved oxygen and contaminant levels have been identified through laboratory and field studies as key indicators of aerobic biodegradation. an important attenuation mechanism. Secondary indicators such as geochemical data, and more intensive methods such as contaminant mass balances, laboratory microcosm studies, and detailed ground water modeling can demonstrate natural attenuation as well. The recommended approach for evaluating natural attenuation is to design site assessment activities so that required data such as dissolved oxygen levels and historical plume flow path concentrations are obtained. With the necessary data, the primary indicators should be applied to evaluate natural attenuation. II the initial evaluation suggests that natural attenuation is a viable corrective action alternative, then a monitoring plan should be implemented to verify the extent of natural attenuation.
Surfactant‐Induced Reductions in Soil Hydraulic Conductivity
Authors: Allred Barry , Brown Glenn O. 
Published: February 2007

AbstractSurfactant solutions are being proposed for in situ flushing of organic contaminants from soils and aquifers. The feasibility of surfactant additives in remediation may depend in large part on how these chemicals affect the hydraulic conductivity of the porous media. While there is evidence in the literature of conductivity loss during surfactant flushing (Miller et al. 1975; Nash et al. 1987), there has been little research on quantifying the process for unconsolidated sediments. Surfactant‐affected hydraulic conductivity reductions were measured in two soils (Teller loam and Daugherty sand). Testing was done with eight surfactants at a variety of concentrations (10‐5 to 10‐l mole/kg), surfactant mixtures, and added solution electrolytes. The Teller was also tested with its organic matter removed. Maximum hydraulic conductivity decreases were 47 percent for the sand and more than two orders of magnitude for the loam. Surfactant concentrations, surfactant mixtures, soil organic content, and added solution electrolytes all affected the degree of conductivity reduction. Results indicate that surfactant‐affected hydraulic conductivity losses should be considered prior to in situ remediation and may preclude surfactant use in some fine grain soils.