bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Use of a Standpipe to Evaluate Ground Water Samplers
Authors: Tai Doreen Y. , Turner Kenneth S. , Garcia Lisa A. 
Published: February 2007

AbstractA standpipe system was developed for testing the reliability of ground water samplers. The unit consists of a stainless steel pipe 5 inches (13 centimeters) in diameter and 100 feet (30.5 meters) in height. It has 14 sampling ports from which control samples can be withdrawn at the same time and position as the samples are collected by a sampler lowered to that position. Test solutions were made in two mixing tanks, totaling 260 gallons (980 liters), by diluting the concentrate of five volatile chlorohydrocarbons in water at two levels of concentration: 10‐to‐30 and 100‐to‐200 parts per billion (micrograms per liter).A gas chromatograph interfaced with a purge‐and‐trap system was used to perform the analyses. Comparisons of the control samples with the sampler‐collected samples have indicated that the three non‐pumping samplers had recoveries in the range of 92.4 to 103.5 percent and the three pumping samplers had recoveries ranging from 97.7 to 101.5 percent.
Investigation of Possible Contamination of Shallow Ground Water by Deeply Injected Liquid Industrial Wastes
Authors: Lesage Suzanne , Jackson Richard E. , Priddle Mark , Beck Paul , Raven Ken G. 
Published: February 2007

AbstractThe objective of this study was to assess the possible impact of deep well disposal operations, conducted between 1958 and 1974, on the ground water quality in a shallow fresh water aquifer beneath Sarnia, Ontario, Canada. Because of the breakout of formation fluids in Sarnia and Port Huron, Michigan, in the early 1970s, it had been hypothesized that liquid waste from the disposal zone in bedrock had leaked through numerous abandoned oil, gas, and salt wells in the area up to the shallow fresh water aquifer and from there to the surface.A monitoring well network of 29 5cm (2 inch) diameter piezometers was established in the thin sand and shale aquifer system, which exists between 30 and 70m (100 and 230 feet) below ground surface. In addition, a 300m (1000 foot) deep borehole was drilled and instrumented with a Westbay multilevel casing, which permitted sampling of the disposal zone.Ground water samples from the shallow monitoring wells and the Westbay multilevel casing were analyzed for volatiles by GC/MS. Those volatile aromatics that were conspicuously present in the deep disposal zone, e.g., ethyl toluenes and trimethyl benzene, were not detected in the shallow monitoring wells. Thus, if contaminants from the disposal zone did indeed migrate to the shallow aquifer, contamination was not widespread and probably consisted mostly of displaced chloride‐rich formation waters.
A Method for Assessing Residual NAPL Based on Organic Chemical Concentrations in Soil Samples
Authors: Feenstra Stan , Mackay Douglas M. , Cherry John A. 
Published: February 2007

AbstractGround water contamination by non‐aqueous phase liquid (NAPL) chemicals is a serious concern at many industrial facilities and waste disposal sites. NAPL in the form of immobile residual contamination, or pools of mobile or potentially mobile NAPL, can represent continuing sources of ground water contamination. In order to develop rational and cost‐effective plans for remediation of soil and ground water contamination at such sites, it is essential to determine if non‐aqueous phase liquid (NAPL) chemicals are present in the subsurface and delineate the zones of NAPL contamination. The presence of NAPL pools may be evident as a floating or sinking phase in monitoring wells. The residual NAPL contamination may be identified in soil samples if residual contents are high and contaminated zones in the soil cores are thick. However, visual identification may not be effective if residual contents are low or if the NAPL residual is distributed heterogeneously in the samples. The chemical analysis of soil samples provides a measure of the total chemical concentration in the soil but cannot determine directly whether NAPL is present in the samples. Qualitatively, soil analyses that exhibit chemical concentrations in the percent range or >10,000 mg/kg would generally be considered to indicate the presence of NAPL. However, the results of soil analyses are seldom used in a quantitative manner to assess the possible presence of residual NAPL contamination when chemical concentrations are lower and the presence of NAPL is not obvious. The assessment of the presence of NAPL in soil samples is possible using the results of chemical and physical analyses of the soil, and the fundamental principles of chemical partitioning in unsaturated or saturated soil. The method requires information on the soil of the type typically considered in ground water contamination studies and provides a simple tool for the investigators of chemical spill and waste disposal sites to assess whether soil chemical analyses indicate the presence of residual NAPL in the subsurface.
LNAPL Distribution in a Cohesionless Soil: A Field Investigation and Cryogenic Sampler
Authors: Durnford D. , Brookman J. , Billica J. , Milligan J. 
Published: February 2007

AbstractLighter‐than‐water Non‐Aqueous Phase Liquids (LNAPLs), such as jet fuels or gasolines, are common contaminants of soils and ground water. However, the total volume and distribution of an LNAPL is difficult to accurately determine during a site investigation. LNAPL that is entrapped in the saturated zone due to fluctuating water table conditions is particularly difficult to quantify. Yet, the amount of entrapped product in the saturated zone is theoretically higher, per volume of soil, than the residual product in the unsaturated zone, and small amounts of LNAPL in the saturated zone can contaminate large volumes of ground water.The only method currently available to quantify the amount of LNAPL is direct soil‐core sampling combined with laboratory analysis of the fluid extracted from the soil cores. However, direct sampling of saturated ground water systems with conventional samplers presents a number of problems. In this study, a new sampler was developed that can be used to retrieve undisturbed soil and pore fluid samples from below the water table in cohesionless soils. The sampler uses carbon dioxide to cool the bottom of a saturated soil sample in situ to near freezing. Results of a field study where a prototype sampler was tested demonstrate the usefulness of a cryogenic sampler and show that the amount of LNAPL entrapped below the water table can be a significant part of the total LNAPL in the soil.
The Geochemistry of Boron in a Landfill Monitoring Program
Authors: Uhlman Kristine 
Published: February 2007

AbstractGround water monitoring data collected during the past eight years at a permitted municipal solid waste (MSW) disposal facility located in the midwestern United States indicated fluctuations in typical leachate indicator parameter concentrations. Apparent trends in the data inferred leachate outbreak, generating suspicion as to the integrity of the landfill liner. Eight ground water monitoring wells were installed in three distinct geologic units at the landfill facility, including glacial drift, silurian dolomite, and a post‐glacial peat fen, which is downgradient from the landfill. Piezometer nests were used to define ground water gradients at the site. Using boron as an indicator, the occurrence of analytes of concern in the downgradient monitoring wells were shown to be indicative of the natural geochemistry of site ground water. This work emphasizes the importance of understanding site hydrogeology during the interpretation of ground water quality data.
Vadose Zone Monitoring with the Neutron Moisture Probe
Authors: Kramer John H. , Cullen Stephen J. , Everett Lome G. 
Published: February 2007

AbstractThe neutron moisture probe is widely applicable to vadose zone monitoring problems which require measuring variable moisture contents. Neutron data are proportional to hydrogen density (modified by local chemistry) and sensitive to wetting fronts as well as changing volumes of hydrocarbon liquids. They cannot, however, be used to confirm contaminant chemistry, nor to detect steady‐state flow. Neutron data are amenable to statistical analysis, providing a measure of the significance of data variations. Detection of incipient moisture changes at numerous monitoring locations is more practical using raw neutron data than data calibrated for moisture content because calibrations suffer from uncertainties associated with soil heterogeneities. When properly applied, the neutron probe is an effective monitoring tool as illustrated by three example applications described in this paper: (1) neutron moisture logs are used to detect subtle lithologic changes and identify monitoring horizons; (2) sequential neutron data are used to track induced saturation at a soil flushing pilot study; and (3) neutron logs from a horizontal access tube beneath a waste facility are used to pinpoint moisture anomalies.
Frequency Domain Electromagnetic Induction Sounding Surveys for Landfill Site Characterization Studies
Authors: Jansen John , Haddad Bassem , Fassbender Wayne , Jurcek Patrick 
Published: February 2007

AbstractA frequency domain electromagnetic induction sounding survey (FDEM) was conducted on a landfill in northern Illinois to determine the depth of fill, locate areas of drum disposal, and locate areas of heavy metal sludge disposal. Sketchy information obtained from interviews of the site personnel identified specific exploration targets and areas of concern. The results of the geophysical survey verified much of the reported disposal history and identified areas suspected to contain hazardous waste.Based on the results of the survey, the thickness of fill was estimated and two areas with highly conductive fill were located. These areas could represent leachate pockets or sludge disposal areas. An area in which the fill appears to be thicker than expected was identified. This area is thought to represent industrial sludge disposal in trenches excavated into the existing fill and underlying soils. An area with several linear in‐phase, quadrature, and conductivity highs was detected. A subsequent magnetometer survey detected linear magnetic anomalies that are believed to be caused by parallel trenches filled with steel drums. This area is believed to be a previously unreported hazardous waste drum disposal cell excavated into the native soil.As of this writing, the results of this survey have not been verified by traditional intrusive methods. When these investigations begin, we expect that information provided by the FDEM survey will reduce project costs by directing subsequent investigations, thereby reducing the number of borings and test pits required to characterize the site. While there is an unavoidable margin of error and uncertainty in remote sensing methods, the subsurface coverage provided by this geophysical survey could not have been reproduced by traditional methods without substantial expense. This paper presents the results of the survey and discusses application of the FDEM method on landfills.
Comparison of Stainless Steel vs. PTFE Miniwells for Monitoring Halogenated Organic Solute Transport
Authors: Bianchi‐Mosquera Gino C. , Mackay Douglas M. 
Published: February 2007

AbstractField tests of organic solute transport behavior have often been monitored using small‐diameter wells (miniwells). To determine if experimental results could be significantly biased by sorption to, desorption from, or diffusion through sampling lines, dissolved concentrations of tetrachloroethene and carbon tetrachloride were measured in ground water samples collected simultaneously from the same spatial location during a forced‐gradient test in the Borden aquifer using polytetrafluoroethene (PTFE) and stainless steel miniwells (1/8‐inch O.D.).A semiautomated organic analytical system was used on‐site to obtain real‐time results, which avoided sample holding problems and permitted optimizing sampling times. The breakthrough curves (plots of concentration vs. time) for both organic compounds indicate that under the conditions of this experiment (low organic solute concentrations, short exposure time of sampling lines to the plume, adequate flushing of sampling lines) there is no significant difference between concentration histories (breakthrough curves) collected using a polytetrafluoroethene sampling line and those collected using a stainless steel sampling line. This suggests that organic solute tailing seen in this and also in a similar transport experiment previously conducted at the site is the result of transport processes in the aquifer rather than an artifact introduced by the PTFE miniwells.
Evaluation of Several Vacuum Solution Samplers in Sand and Silt Loam at Several Water Potentials
Authors: McGuire P.E. , Lowery B. 
Published: February 2007

AbstractUntil recently, there was little information available on the water collection capabilities of pore water samplers. This study was conducted to evaluate the performance of ceramic, fritted‐glass, stainless steel, and polytetrafluoroethylene (PTFE) porous samplers in sand and silt loam soil columns over a range of soil water potentials. Soil solution intake for samplers was determined by application of constant and falling vacuums. Constant vacuum was applied for a three‐day period when soils were at field moisture capacity. The PTFE samplers did not function when tested with a constant or falling vacuum. With a 50‐kPa constant vacuum, the ceramic sampler collected the greatest sample volume (average 20 mL) from the sand. With a constant 25‐kPa vacuum, the stainless steel sampler collected the greatest sample volume (average 81 mL) from the silt loam soil. Sampler performance with a fixed volume of vacuum was evaluated by applying 100 kPa vacuum to a 1‐liter reservoir. With this falling vacuum, samplers were tested until no further solution was collected over a 10‐day test period. With a falling vacuum, fritted‐glass and stainless steel samplers, with relatively larger pores and greater hydraulic conductance, collected a greater volume of sample and at a faster rate than ceramic samplers in sand soil that was nearly saturated. When the volume was normalized with respect to sampler surface area, for the falling vacuum tests in silt loam soil at field moisture capacity, the volume collected by fritted glass was significantly higher than those from other samplers. In sand at field moisture capacity or silt loam at soil water tensions ≧30 kPa, ceramic samplers maintained vacuums near 70 kPa and collected more sample than the other samplers during the 10‐day test period.
A Dry Injection System for the Emplacement of Filter Packs and Annular Seals in Ground Water Monitoring Wells
Authors: Boyle D.R. 
Published: February 2007

AbstractThe reliability of filter pack and annular seal emplacements, and the degree of integrity of installed seals, are two of the most important factors to be considered when both installing and later utilizing ground water monitoring wells.Numerous, and often costly, problems of using existing methods of installing filter packs and annular seals during the construction of ground water monitoring wells have led to the development of a technique of installing these monitoring well components using a dry injection system.The dry injection system has been used to construct monitoring wells in extremely complex overburden/bedrock environments with a variety of drilling techniques. The system has shown that a high degree of reliability in the, construction of monitoring wells and greater confidence in obtaining representative ground water samples can be achieved over existing methods of filter pack and annular seal emplacement. The system has also been more cost effective than existing methods, especially for deep boreholes and multilevel monitoring system installations.
Comparison of Two Integrated Methods for the Collection and Analysis of Volatile Organic Compounds in Ground Water
Authors: Patterson Bradley M. , Power Terry R. , Barber Chris 
Published: February 2007

AbstractThe principal difficulties with determinations of volatile organic compounds (VOCs) in ground water are the reliability of sampling procedures and analytical methods. Two integrated methods have been developed for routine sampling, processing, and analysis of VOCs in ground water. These methods involve in situ collection of ground water using a modified syringe sampler from PVC piezometers or using dedicated glass syringes from stainless steel multilevel bores. The samples are processed in the syringe using purge and trap or microsolvent extraction and analyzed by GC/MSD.The modified purge‐and‐trap method is time‐consuming and limited to volatile organic compounds. However, it is extremely sensitive and flexible: the volume of sample used can be varied by the use of different‐size glass syringes (sample volumes from 1 to 100 mL).In cases where extremely low sensitivity (<10 mg 1−1) is not critical, the microextraction technique is a more cost‐effective method, allowing twice as many samples to be analyzed in the same time as the purge‐and‐trap method. It enables less volatile compounds such as polynuclear aromatic hydrocarbons, phenol, and cresols to be analyzed in the same GC run. Also, the microextraction method can be used in the field to avoid delays associated with transportation of ground water samples to the laboratory.
Investigation and Remediation of Petroleum Product Releases from Residential Storage Tanks
Authors: Pearson Gary , Oudijk Gil 
Published: February 2007

AbstractReleases of petroleum products from leaking residential storage tanks are a growing problem in the stale of New Jersey. Approximately two releases per day have been reported to the New Jersey Department of Environmental Protection. Product releases may cause aquifers to become contaminated, may affect surface water, or cause vapor problems inside households. As of 1992, there arc no federal or state regulations pertaining to the maintenance and monitoring of residential petroleum storage tanks. Regulations are essential for protecting drinking water supplies. The regulations must address installation procedures, lank materials, monitoring, and tank location.
Application of Electromagnetic Logging to Contamination Investigations in Glacial Sand‐and‐Gravel Aquifers
Authors: Williams John H. , Lapham Wayne W. , Barringer Thomas H. 
Published: February 2007

AbstractElectromagnetic (EM) logging provides an efficient method for high‐resolution, vertical delineation of electrically conductive contamination in glacial sand‐and‐gravel aquifers. LM. gamma, and lithologic logs and specific conductance data from sand‐and‐gravel aquifers at five sites in the northeastern United States were analyzed to define the relation of KM conductivity to aquifer lithology and water quality. Municipal waste disposal, septic waste discharge, or highway deicing salt application at these sites has caused contaminant plumes in which the dissolved solids concentration and specific conductance of ground water exceed background levels by as much as 10 to 20 limes.The major hydrogeologic factors that affected KM log response at the five sites were the dissolved solids concentration of the ground water and the silt and clay content in the aquifer. KM conductivity of sand and gravel with uncontaminated water ranged from less than 5 to about 10 millisiemens per meter (mS/m); that of silt and clay zones ranged from about 15 to 45 mS/m: and that of the more highly contaminated zones in sand and gravel ranged from about 10 to more than 80 mS/m. Specific conductance of water samples from screened intervals in sand and gravel at selected monitoring well installations was significantly correlated with KM conductivity.CM logging can be used in glacial sand‐and‐gravel aquifer investigations to (1) determine optimum depths for the placement of monitoring well screens: (2) provide a nearly continuous vertical profile of specific conductance to complement depth‐specific water quality samples; and (3) identify temporal changes in water quality through sequential logging. Detailed lithologic or gamma logs, preferably both, need to be collected along with the F.M logs to define zones in which elevated EM conductivity is caused by the presence of sill and clay beds rather than contamination.
Detection of Contaminant Plumes by Borehole Geophysical Logging
Authors: Mack Thomas J. 
Published: February 2007

AbstractTwo borehole geophysical methods—electromagnetic induction and natural gamma radiation logs—were used to vertically delineate landfill leachate plumes in a glacial aquifer. Geophysical logs of monitoring wells near two land‐fills in a glacial aquifer in west‐central Vermont show that borehole geophysical methods can aid in interpretation of geologic logs and placement of monitoring well screens to sample landfill leachate plumes.Zones of high electrical conductance were delineated from the electromagnetic log in wells near two landfills. Some of these zones were found to correlate with silt and clay units on the basis of drilling and gamma logs. Monitoring wells were screened specifically in zones of high electrical conductivity that did not correlate to a silt or clay unit. Zones of high electrical conductivity that did not correlate to a silt or clay unit were caused by the presence of ground water with a high specific conductance, generally from 1000 to 2370 μS/cm (microsiemens per centimeter at 25 degrees Celsius). Ambient ground water in the study area has a specific conductance of approximately 200 to 400 μS/cm. Landfill leachate plumes were found to be approximately 5 to 20 feet thick and to be near the water table surface.
EPA's Approach to Vadose Zone Monitoring at RCRA Facilities
Authors: Durant Neal D. , Myers Vernon B. , Eccles Lawrence A. 
Published: February 2007

AbstractThe U.S. Environmental Protection Agency (EPA) recently proposed to amend federal regulations to require vadose zone monitoring at certain hazardous waste facilities. To support this proposal, EPA evaluated previous policy on vadose zone monitoring and examined advances in vadose zone monitoring technology. Changes in EPA vadose zone monitoring policy were driven by demonstrated advances in the available monitoring technology and improvements in understanding of vadose zone processes/When used under the appropriate conditions, currently available direct and indirect monitoring methods can effectively detect contamination that may leak from hazardous waste facilities into the vadose zone. Direct techniques examined include soil‐core monitoring and soil‐pore liquid monitoring. Indirect techniques examined include soil‐gas monitoring, neutron moderation, complex resistivity, ground‐penetrating radar, and electrical resistivity. Properly designed vadose zone monitoring networks can act as a complement to saturated zone monitoring networks at numerous hazardous waste facilities. At certain facilities, particularly those in arid climates where the saturated zone is relatively deep, effective vadose zone monitoring may allow a reduction in the scope of saturated zone monitoring programs.