bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitization of the Trigeminal Sensory System During Different Stages of the Rat Estrous Cycle: Implications for Menstrual Migraine
Authors: Martin Vincent T. , Lee James , Behbehani Michael M.
Published: February 2007

Objectives.—To determine if the sensitization of the trigeminal system changes after dural activation of the trigeminal nerve during different stages of the rat estrous cycle.

Background.—The specific mechanisms through which ovarian hormones trigger menstrual migraine are currently unknown. Past animal studies have suggested that the response properties of the trigeminal nucleus caudalis (TNC) may change during the different phases of the rat estrous cycle, but none have been performed in an experimental paradigm for migraine headache.

Methods.—Sixty‐one cycling female Sprague–Dawley rats were used for these experiments. The stage of the estrous cycle of each animal was identified by examination of the cellular morphology of vaginal lavage. The animals were anesthetized and a 7 mm portion of the skull was removed that was centered over the sagittal sinus. A tungsten electrode was used to record from neurons in the TNC or CI‐CIII regions. Only neurons that had both dural and cutaneous receptive fields were used for these experiments. Facial receptive field sizes (RFS) were mapped and neurophysiologic response properties of the TNC/CI‐CIII neurons to cutaneous and dural stimuli was ascertained before and after application of capsaicin to the dura. One‐way and repeated measure analysis of variance were used to compare changes in RFS and response properties of TNC/CI‐CIII neurons from animals during different stages of the rat estrous cycle.

Results.—When data were analyzed individually for each stage, there was greater enlargement of cutaneous receptive fields and enhanced sensitivity of the trigeminal system to cutaneous stimuli during proestrus as compared to metestrus and diestrus after dural activation with capsaicin (P values <.05). When data were pooled from stages with similar hormonal milieus, the percent change in the response magnitude of TNC neurons to electrical stimulation of the dura was greater and receptive field enlargement was larger from the proestrous/estrous group compared to those from the metestrous/diestrous group after administration of capsaicin (P values <.05).

Conclusions.—There is enhanced sensitization of the trigeminal system during the later halves of proestrus and estrus, which represent stages of the rat estrous cycle during and immediately following an abrupt decline in ovarian hormones. If similar changes occur during the human menstrual cycle these results could have important implications for menstrual migraine.
Cation‐Chloride Cotransporters and GABA‐ergic Innervation in the Human Epileptic Hippocampus
Authors: Muñoz Alberto , Méndez Pablo , DeFelipe Javier , Alvarez‐Leefmans Francisco Javier
Published: February 2007

Summary:  Intracellular chloride concentration, [Cl−]i, determines the polarity of GABAA‐induced neuronal Cl− currents. In neurons, [Cl−]i is set by the activity of Na+, K+, 2Cl− cotransporters (NKCC) such as NKCC1, which physiologically accumulate Cl− in the cell, and Cl− extruding K+, Cl− cotransporters like KCC2. Alterations in the balance of NKCC1 and KCC2 activity may determine the switch from hyperpolarizing to depolarizing effects of GABA, reported in the subiculum of epileptic patients with hippocampal sclerosis. We studied the expression of NKCC (putative NKCC1) and KCC2 in human normal temporal neocortex by Western blot analysis and in normal and epileptic regions of the subiculum and the hippocampus proper using immunocytochemistry. Western blot analysis revealed NKCC and KCC2 proteins in adult human neocortical membranes similar to those in rat neocortex.

NKCC and KCC2 immunolabeling of pyramidal and nonpyramidal cells was found in normal and epileptic hippocampal formation. In the transition between the subiculum with sclerotic regions of CA1, known to exhibit epileptogenic activity, double immunolabeling of NKCC and KCC2 revealed that approximately 20% of the NKCC‐immunoreactive neurons do not express KCC2. In these same areas some neurons were distinctly hyperinnervated by parvalbumin (PV) positive hypertrophic basket formations that innervated mostly neurons expressing NKCC (74%) and to a lesser extent NKCC‐immunonegative neurons (26%). Hypertrophic basket formations also innervated KCC2‐positive (76%) and ‐negative (24%) neurons. The data suggest that changes in the relative expression of NKCC1 and KCC2 in neurons having aberrant GABA‐ergic hyperinnervation may contribute to epileptiform activity in the subicular regions adjacent to sclerotic areas of the hippocampus.
We Are All Advocates
Authors: Ekegren Kathryn
Published: February 2007

The Advocate is a forum for exploring our roles as advocates for the children and families we serve.
Flying Home
Authors: Dunn Kathleen J.
Published: February 2007

In the rapidly progressing field of critical care, the diverse delivery of such care seems to be reaching new “heights.“ In particular, aeromedical transport of critically ill patients involves detailed preparation for the worst possibilities but with expectations for the best outcomes. The following case is presented as testimony to the challenges of critical care transport.
Characteristics of School‐Age Children Who Had Colic as Infants: Mothers' Views
Authors: Neu Madalynn , Keefe Maureen R.
Published: February 2007

ISSUES AND PURPOSE. To describe the behavioral style and personality characteristics of young school‐age children who were identified as colicky infants and the parents' perspective of any residual behaviors or effects.

DESIGN AND METHODS. A qualitative descriptive design with mothers of 12 children identified with colic as infants and 8 mothers of children who did not have colic.

RESULTS. Three themes of children who had colic: independence/self‐reliance, activity, and emotional lability/intensity.

PRACTICE IMPLICATIONS. Children generally were perceived as normal and healthy. Residual feelings, parent‐child interaction issues, and perceived or real persistent child characteristics may surface in families who experienced colic, especially during stressful periods.
Ebb and Flow When Navigating Adolescence: Predictors of Daily Hassles Among African‐American Adolescent Girls
Authors: Guthrie Barbara J. , Young Amy M. , Boyd Carol J. , Kintner Eileen K.
Published: February 2007

ISSUES AND PURPOSE. To examine the nature of daily hassles as perceived by African‐American adolescen females.

DESIGN AND METHODS. As part of a larger, cross‐sectional study, nonrandom network sampling technique was used to survey 178 adolescent girls between the ages of 11 and 19.

RESULTS. This study found that the most common hassles were school and academic, followed by family and economic hassles, peer and social hassles, and personal safety hassles. Socioeconomic factors were strongly associated with the level of hassles reported.

PRACTICE IMPLICATIONS. Assess African‐American girl's perception of daily hassles, specifically school‐ and family‐ related hassles, and also examine the interrelationship between the type of hassles and health problems.
Ground Water Quality In the Aquifer of the Upper Mad River Valley 1940 to 1983
Authors: Pennino James D.
Published: February 2007

More than 40 years of ground water quality monitoring data from the aquifer of the Upper Mad River Valley have been accumulated by various agencies in Ohio. The data consist of concentrations for more than 30 chemical substances found in the ground water. Evaluation of this data using statistical analysis, tables and graphs indicates that there have been moderate increases in total dissolved solids, sulfate, fluoride, calcium, magnesium and potassium. More significant increases were discovered for chloride and sodium. Iron and zinc show a general decline in concentration. The metals arsenic, barium and lead also show increases in recent years. However, large variations in the concentrations and limited data for these metals limit the reliability of the apparent trends shown in the tabulated data.

The increases in chloride and sodium are attributed to the use of road de‐icing salt. Increases in sulfate and potassium may be due to use of fertilizers in a region which is largely agricultural. The most recent data may indicate that the ground water quality is improving in terms of these two parameters. Although most of the data indicate increases in concentrations with time, inconsistencies in sampling procedures and difficulties in assessing many factors which affect ground water quality preclude the broad conclusion that urbanization and industrialization have caused regional ground water quality degradation.

The inability to interpret much of the data underlies the need for an integrated environmental monitoring program. Such a program should provide a data base for assessing factors such as air and river quality and historical land use practices so that their impact on ground water quality in the Mad River Valley can be better understood.
Innovative Sampling Techniques for Ground Water Monitoring at Hazardous Waste Sites
Authors: Emenhiser Thomas C. , Singh Udai P.
Published: February 2007

The authors have recently used several innovative sampling techniques for ground water monitoring at hazardous waste sites. Two of these techniques were used for the first time on the Biscayne Aquifer Super‐fund Project in Miami, Florida. This is the largest sampling program conducted so far under the U.S. Environmental Protection Agency (EPA) Superfund Program.

One sampling technique involved the use of the new ISCO Model 2600 submersible portable well sampling pump. A compressed air source forces water from the well into the pump casing and then delivers it to the surface (through a pulsating action). This pump was used in wells that could not be sampled with surface lift devices.

Another sampling technique involved the use of a Teflon manifold sampling device. The manifold is inserted into the top of the sampling bottle and a peristaltic pump creates a vacuum to draw the water sample from the well into the bottle. The major advantage of using this sampling technique for ground water monitoring at hazardous waste sites is the direct delivery of the water sample into the collection container. In this manner, the potential for contamination is reduced because, prior to delivery to the sample container, the sample contacts only the Teflon, which is well‐known for its inert properties.

Quality assurance results from the Superfund project indicate that these sampling techniques are successful in reducing cross‐contamination between monitoring wells. Analysis of field blanks using organic‐free water in contact with these sampling devices did not show any concentration at or above the method detection limit for each priority pollutant.
An Integrated Ground Water Monitoring Program Using Multilevel Gas‐Driven Samplers and Conventional Monitoring Wells
Authors: Nazar Andrzej , Prieur James , Threlfall Daniel
Published: February 2007

Hydrogeologic and ground water quality data obtained from a gas‐driven multilevel sampler system and a polyvinyl chloride (PVC) monitoring well nest with the same aquifer communication intervals are compared. All monitoring points are in close proximity to each other.

The study was conducted at an eight‐acre uncontrolled hazardous waste site. The site is located in an alluvial valley composed of approximately 40 feet of alluvium overlying shale bedrock. The ground water at the site is contaminated with various organic constituents.

A ground water monitoring network consisting of 26 conventional monitoring wells, nine observation well points, and six multilevel gas‐driven samplers was established to characterize the hydrogeologic regime and define the vertical and horizontal extent of contamination in the vicinity of the abandoned chemical plant. As part of this study, a multilevel monitoring system was installed adjacent to a well nest. The communication zones of the multilevel samplers were placed at the same elevation as the sand packs of the well nest. The multilevel sampler system and well nest are located in a contaminated area directly downgradient of the site. A comparison of the vertical head distribution and ground water quality was performed between the well nest and the multilevel sampling system.

The gas‐driven multilevel sampling system consists of three gas‐driven samplers that monitor separate intervals in the unconsolidated materials. The well nest, composed of two PVC monitoring wells in separate boreholes, has the same communication interval as the other two gas‐driven samplers.

Hydraulic head information for each multilevel sampler was obtained using capillary tubing. This was compared with heads obtained from the well nest utilizing an electric water level indicator.

Chemical analyses from the PVC and multilevel sampler wells were performed and compared with one another. The analyses included organic acids, base neutrals, pesticides, PCBs, metals, volatile organics, TOX, TOC, CN, pH and specific conductance.
The Suction Side Sample Catcher in Ground Water Quality Sampling
Authors: Armstrong Richard , McLaren Frederick R.
Published: February 2007

A suction side sample collector (SSSC) is a contrivance installed hydraulically ahead of the intake port of a pumping device. This paper describes construction and operational details of SSSCs fitted to a submersible pump with packer for use in a 6‐inch cased borehole, an air lift pump with packer for use in a 1‐inch or 2.5‐inch cased borehole, a bladder pump for use in a casing of 2‐inch or greater diameter, and a jet pump with packer for use in a 2‐inch cased borehole.

Each form of SSSC has been thoroughly tested in ground water quality sampling for volatile organic chemicals. Comparative data for samples collected with the SSSCs and conventional sample collecting gear are presented. The SSSC is demonstrated to be superior to other methods of collecting volatile organic chemical samples owing to its freedom from contamination by the pump delivery line and to its mode of collecting the sample from a position in the well remote from disturbance by the pumping technique.

SSSCs are conveniently decontaminated, easily transported, and can be used to deliver samples to the laboratory while still at formation pressure. The air‐lift pumps, described in this paper for use with SSSCs in 1‐ and 2.5‐inch casings, have pumping capacities greater than obtained by other methods that can operate in these small casings. Discharge rates of up to 2 gpm are routinely achieved with the 1‐inch model and higher rates are common With the 2.5‐inch model. The use of packers with these pumps reduces the time needed to replace the water in the casing with fresh water from the formation.
Electrical Resistivity Studies to Delimit Zones of Acceptable Ground Water Quality
Authors: Ringstad Clyde A. , Bugenig Dale C.
Published: February 2007

A total of four vertical electrical soundings were conducted in a layered andesitic rock aquifer known in places to yield ground water with total dissolved solids (TDS) in excess of 2,000 milligrams per liter (mg/L). The objective of the soundings was to locate zones of moderate to high permeability but with acceptable chemical quality.

The resistivity of a geologic unit is a function that includes the quantity of total dissolved solids in the interstitial water and the distribution of the water within the unit. Thus, the resistivity of most granular soils and rocks is controlled more by porosity, water content and water quality than by the conductivity of the matrix materials.

The electrical data delimited a drill site where it was believed that ground water of acceptable chemical quality could be expected. Completion and test pumping of two exploration wells confirmed the electrical sounding results.

The first test well drilled prior to the survey yielded only small amounts of ground water with total dissolved solids in excess of 2,000 mg/L. The second exploration well drilled at the site as a result of the electrical study yielded in excess of 100 gallons per minute of ground water with total dissolved solids of 830 mg/L.
Techniques and Equipment Used in Contaminant Detection at Hoe Creek Underground Coal Gasification Experimental Site
Authors: Davidson Stephen C. , McTernan Elizabeth M. , Kunzel Robert G.
Published: February 2007

Data from an existing network of ground water monitoring wells at the U.S. Department of Energy (DOE) Hoe Creek Underground Coal Gasification (UCG) Experimental Site indicated that organic contaminants, particularly phenols produced during gasification experiments, were threatening neighboring ground water resources. The existing monitoring well network was sparse and further definition of the extent and direction of contaminant migration was needed. Additionally, water level data, important in determining flow directions, was incomplete. A field program was designed and implemented to locate and define the organic contamination and expand the existing ground water monitoring program. The program utilized field analysis of phenol for contaminant detection and well location, followed by completion using gas‐drive ground water samplers/piezometers. Geophysical logging was used to permit optimum placement of the samplers. The geologic aspects of the site posed some interesting problems to the installation of the samplers. The contaminant plume edge was defined in the east, west and south directions during the field program. Further work is needed in the north direction.
A Simple Pneumatic Device and Technique for Performing Rising Water Level Slug Tests
Authors: Leap Darrell I.
Published: February 2007

Transmissivity can be estimated by several well documented methods employing data from rising water level slug tests in wells. A very simple and relatively inexpensive system can be constructed to lower the water level in a well. Compressed air is injected through a sealed device called a well head manifold, which screws onto the casing top and contains an air pressure gauge, an air entry valve, a quick release valve and a multi‐channel water level indicator or a pressure transducer. Either of the latter is lowered into the well prior to pressurization.

Compressed air is injected into the casing at a low rate through the manifold, depressing the water level a desired amount. After stabilization, the quick release valve is opened and the air pressure inside the casing is reduced to atmospheric pressure instantaneously; the water level then starts to rise. Successive elevations of the rising water level are determined with the indicator or transducer and their elapsed times from valve opening are recorded. Plots of water level recovery vs. time can then be used to estimate transmissivity by the published methods of Cooper, Bredehoeft and Papadopulos (1967), Ferris and Knowles (1954) and Hvorslev(1951).

All of the items used for construction, with the exception of the quick release valve, can be bought off the shelf. The valve can be easily constructed in a machine shop. The total cost of the device, exclusive of the transducer, should be less than $500.
Design and Implementation of Evapotranspiration Measuring Equipment for Owens Valley, California
Authors: Simpson Michael R. , Duell Lowell F.W.
Published: February 2007

As part of a plant survivability and ground water study in Owens Valley, California, semipermanent installations are used to measure continuous range‐land evapotranspiration in the valley's phreatophyte community. A proposed mobile installation also has been designed. The semipermanent micrometeoro‐logical station collects continuous data for solution of the Bowen ratio/energy budget equation and the Penman combination equation. Three sites were chosen for this type of installation to provide a representative sampling of Owens Valley. The proposed mobile aerodynamic installation should be capable of calculating evapotranspiration by the eddy correlation method. This instrumentation will be used throughout the valley for short periods of time (up to five days). Many problems with equipment operation, calibration and design have been identified and resolved by means of improved calibration techniques, systematic error‐removal techniques, reduced cycle times, modified equipment design and proper observer training. The collected evapotranspiration data will be instrumental in developing a one‐dimensional evapotranspiration flux algorithm for a model of valleywide ground water flow.
Surface and Borehole Geophysical Methods in Ground Water Investigations
Authors: Mickam James T. , Levy Benjamin S. , Lee George W.
Published: February 2007

Ground water flow in karst terranes generally occurs in the solution channels of carbonate aquifers. A hydrogeologist may utilize borehole geophysical methods to identify these solution channels in aquifers. Two specific methods that are applicable in karst terrains are:

1. Natural gamma ray logging

2. Borehole caliper logging.

Gamma ray logging can detect the presence of inter‐bedded strata in the main limestone unit, such as shale, which emit high levels of gamma radiation. Gamma ray logging can also detect clay deposits in solution channels that may act to restrict the flow of ground water. The areal extent of these rock strata or clay‐filled solution channels can be determined when gamma ray logs are conducted at several borehole locations across the site of investigation.

Borehole caliper logging can be employed to determine the presences of solution channels within the aquifer when penetrated by a borehole. In addition, since shale layers and clay filling are less resistant than the surrounding limestone, the caliper log may detect both the presence and the thickness of shale or clay layers in the aquifer.

Gamma ray logs can be used in conjunction with caliper logs to provide data on the stratigraphic location and thickness of solution channels and clay and shale layers within a limestone aquifer. This information is valuable to the hydrogeologist performing investigations at sites located in limestone terranes because ground water flow preferentially occurs along solution channels.
Constraints and Categories of Vadose Zone Monitoring Devices
Authors: Everett Lorne G. , Hoylman Edward W. , Wilson L. Graham , McMillion Leslie G.
Published: February 2007

Traditional monitoring methods using chemical analysis of ground water samples to detect pollutant migration are being superseded or used in conjunction with innovative approaches. A need to detect pollutants before they reach the water table has drawn interest to vadose (unsaturated) zone monitoring and brought together hydrogeologists, soil scientists and agricultural engineers who have been working on this subject for years.

Recent studies have identified over 50 different types of vadose zone monitoring devices and methods that have optimum utility in varying hydrogeologic settings. In general, measurements made in the vadose zone are trying to define storage, transmission of liquid waste in terms of flux and velocity, and pollutant mobility.

Criteria for the selection of alternative vadose zone monitoring methods are important for the development of site‐specific systems. These criteria include: type of site; applicability to new, active, and abandoned sites; power requirements; depth limitations; multiple use capability; type of data collection system; reliability and life expectancy; degree of operational complexity; direct versus indirect methods; applicability to alternate media; effect on flow regime; and effect of hazardous waste on sampling or measurements. Application of the selection criteria is discussed in Everett et al. (1982a).
Developing Objectives for the Ground Water Quality Monitoring Network of the Salinas River
Authors: Showalter Patricia
Published: February 2007

This article describes how objectives were developed and applied to design a ground water quality monitoring network for the Salinas River drainage basin in central California. Four agencies worked together: the USGS as network designer, the Central Coast Regional Water Quality Control Board as network manager, and Monterey and San Luis Obispo county agencies as data providers. After investigating the basin's ground water quality problems, a list of objectives was developed. These objectives were written as concise statements. The network designers and managers arranged the objectives in the order of importance and set priorities for them. An ideal network was designed to meet all of the monitoring objectives. In the ideal network exercise, budget and manpower constraints were ignored. Each monitoring location was chosen for a specific objective or group of objectives. The ideal network was compared with the existing network to identify where both more and less monitoring was needed. Then a proposed network was chosen. The ideal and existing networks were composited to produce the proposed network, but budget and manpower were considered. To keep the network at a realistic size, monitoring was only recommended to meet the most important objectives. Existing monitoring sites were retained to meet any of the objectives.
Control of Ground Water Contamination at an Active Uranium Mill
Authors: White Richard B. , Gainer Randolph B.
Published: February 2007

Seepage from tailings ponds associated with an active uranium mill in Utah has resulted in contamination of ground water contained in the Dakota‐Burro Canyon Formation. This aquifer is used in the area as a supply for domestic and industrial wells.

Results of very low‐frequency electromagnetic surveys and ground water quality investigations at the site indicated that the flow of ground water and contaminants is primarily fracture‐controlled. Pumping tests were conducted to determine the hydraulic characteristics of the fractured system. The extent of contaminant migration was then determined using an analytical model of transport in fractured aquifers.

Based on these investigations, a plan was designed to control future and remediate past ground water contamination. This plan consists of pumping from a single well intersecting the main fracture that transports contaminants off the site. The effectiveness of the plan was analytically modeled, taking account of the anisotropy of the ground water system. Subsequent monitoring of water levels in the area indicates that the plan has been effective since its inception in November 1983.
Factors Requiring Resolution in Installing Vadose Zone Monitoring Systems
Authors: Robbins Gary A. , Gemmell Michael M.
Published: February 2007

Increasingly, regulations by federal, state and local agencies are being developed that require the installation of vadose zone monitoring systems for hazardous chemical facilities in addition to, or in lieu of, conventional ground water monitoring wells. Compared to a ground water monitoring approach, vadose zone monitoring systems may permit earlier detection of chemical leakage and less costly cleanup of contamination. The effective use of vadose zone monitoring systems in detecting contamination depends on many factors. Without proper consideration of these factors, a vadose zone monitoring system may not give as high a level of reliability as a ground water monitoring system.

Major factors to consider in installing a vadose zone monitoring system are: type of instrument to use, number of instruments, depth and location of instruments, and frequency of monitoring. Means to evaluate these factors in a comprehensive fashion have been lacking. Based on recent experience in installing and operating vadose zone monitoring systems, criteria and methods useful in resolving the preceding factors have been developed. Types of instruments can be classified as either direct (lysimeter, vapor probe) or indirect (tensiometer, conductivity probe). A combination of the two is needed for reliability. The depth, location and number of instruments depend on the geometry of the facility, the number and size of likely contaminant leakage points in engineered barriers, properties of the material being monitored, the effective radius of monitoring for each instrument, vadose zone properties, and types of remedial actions that are available. The freqency of monitoring largely depends on the rate of movement of the contaminant. Evaluating the preceding factors requires some level of modeling and preliminary field testing.
Underground Storage Tank Monitoring: Observation Well Based Systems
Authors: Scheinfeld Raymond A. , Robertson John B. , Schwendeman Todd G.
Published: February 2007

A growing number of state and local governments and petroleum‐related companies require the use of release detection systems for underground petroleum storage tanks. This has resulted in a confusing array of commercially available petroleum product detection devices, many of which have not been extensively field‐tested. These systems, which are installed in ground water observation wells, vapor wells or U‐tubes, include hydrocarbon‐detecting paste, bailers, interface probes, electrical resistivity sensors, thermal‐conductivity sensors, hydrocarbon‐soluble devices, hydrocarbon‐permeable materials and vapor detectors. This paper describes the available state‐of‐the‐art technology for leak detection and the application for which each system is best suited.
Practical Application of Theoretical Models to Magnetometer Surveys on Hazardous Waste Disposal Sites — A Case History
Authors: Gilkeson Robert H. , Heigold Paul C. , Laymon Douglas E.
Published: February 2007

Wastes were to be exhumed and removed from a hazardous and chemical waste disposal site. The major disposal practice was shallow burial of wastes in metal drums in parallel trenches. The actual boundaries of the trenches beneath the landscaped cover were not accurately known.

Theoretical two‐dimensional models were used to evaluate the application of magnetic methods to define trench boundaries on the disposal site. The models predicted that both the total field and the vertical component anomalies were diagnostic; however, the vertical component anomaly was more focused on the trench boundaries.

A survey with a vertical component fluxgate magnetometer was successful in defining trench boundaries. Observations made along traverses that trended perpendicular to the long axis of the parallel trenches indicated vertical magnetic intensity values with a cyclical pattern of large positive values over trenches and large negative values over intertrench corridors. Vertical magnetic intensity values determined with theoretical two‐dimensional models compared favorably to the observed vertical magnetic values. The models were used to constrain the interpretation of the field observations to define trench boundaries; the magnetic survey defined trench boundaries with an accuracy within ± 2 feet.
Low‐Cost Apparatus for On‐Site Monitoring of Methane in Ground Water
Authors: Harrison Samuel S.
Published: February 2007

An upsurge in oil‐ and gas‐well drilling in northwestern Pennsylvania and western New York has been accompanied by several incidents of contamination of ground water by methane. Determining which well is causing the contamination is extremely difficult if more than one gas or oil well is present in the area.

The fact that the solubility of methane decreases as the pressure on ground water decreases provides a quantitative basis for monitoring changes in the amount of methane in the ground water. Quantitative measurements of the volume of methane given off by ground water pumped from a well as the water enters atmospheric pressure permit detection of temporal changes in the gas content which are too subtle to be detected visually. These gas volume changes may, in some cases, be correlated with variations in the pressure of methane in the annulus of nearby individual gas/oil wells and thus may provide a means of pinpointing the gas/oil well that is causing the methane contamination.

The basic principle of the gas‐volume monitoring apparatus (GVMA) described in this paper is that as a measured amount of ground water enters atmospheric pressure the gas which comes out of solution is trapped and measured. The GVMA can be constructed of materials costing less than $100 and requires no special skills to assemble or operate. In a recent study conducted in a western New York village, four homeowners were able to collect quantitative gas‐volume data from their household water wells daily in about one‐half hour. Unlike laboratory analyses for dissolved methane, there is no cost involved in monitoring with the GVMA beyond the initial instrument cost and operator time. Another advantage is that the data are available immediately.
Micro Computers Applied to Ground Water Monitoring and Testing
Authors: Brqnnaka Larry K. , Keefe Lawrence R.
Published: February 2007

Micro computers have been demonstrated to be a most valuable, cost‐effective means of long‐ and short‐term data acquisition for ground water investigations and installations. A system can readily be assembled for the cost of labor saved in the field, or for the same cost as other conventional instruments, which perform only a fraction of the functions of the computer system

Documented in this article are systems which have been developed and used for simultaneous monitoring of several wells during aquifer tests, and systems installed for long‐term monitoring of piezometric surface fluctuations. Both systems can be contained in a small suitcase or insulated cooler. Specific features of the systems include multiple channel capacity, one‐month maintenance period, variable computer controlled reading intervals, magnetic tape data storage, data reduction and analysis capabilities while maintaining monitoring, graphic display of time and measurements, hard copy capability and barometric pressure change corrections.

Other applications are examined for the complete control of pumping tests, including pumping rate; in situ permeability tests; monitoring changes; and even strain. The pressure transducer system may also be applied for river gauging and current measurement.
Drilling and Constructing Monitoring Wells with Hollow‐Stem Augers Part 1: Drilling Considerations
Authors: Hackett Glen
Published: February 2007

Hollow‐stem augers are a widely used drilling method for constructing monitoring wells in unconsolidated materials. The drilling procedures used when constructing monitoring wells with hollow‐stem augers, however, are neither standardized nor thoroughly documented in the published literature.

Variations in drilling procedures and techniques may occur as a result of the: (1) type of auger drill equipment and formation samplers used; (2) hydrogeologic conditions at the site, especially where heaving sands occur; and (3) known or suspected presence of contaminated zones, where there is a potential for the vertical movement of contaminants within the borehole.

In a saturated zone in which heaving sands occur, changes in equipment and drilling techniques are required to provide a positive pressure head of water within the auger column. This may require the addition of clean water or other drilling fluid inside the augers.

When monitoring the quality of ground water below a known contaminated zone, hollow‐stem auger drilling may not be advisable unless protective surface casing can be installed. Depending on the site hydrogeology, conventional hollow‐stem auger drilling techniques alone may not be adequate for the installation of the protective surface casing. A hybrid drilling method may be needed that combines conventional hollow‐stem auger drilling with a casing driving technique that advances the borehole and surface casing simultaneously.
Potential for Solute Retardation on Monitoring Well Sand Packs and Its Effect on Purging Requirements for Ground Water Sampling
Authors: Palmer Carl D. , Keely Joseph F. , Fish William
Published: February 2007

Monitoring well sand packs are theoretically capable of retarding metal ions and organic contaminants. If this retardation does indeed occur it may have a significant effect on the purging requirements of newly installed monitoring wells. Calculations based on mass balance and retardation concepts demonstrate that if common guidelines for well purging are followed, contaminants may not be detected or may be detected in lower concentrations than are actually present in the ground water. This problem is greatest in relatively shallow wells installed in low to moderate permeability materials. In most cases, the effect of solute retardation in the sand pack can be avoided simply by additional purging prior to the first sampling of the monitoring well. Common purging guidelines can then be applied to subsequent samplings. The methodology outlined in this paper can be used to calculate the purging requirements of existing monitoring wells or it may be applied to alternative monitoring well designs to test which will require the smallest volume of purged water.
Opinion I
Authors: Braids Olin C.
Published: February 2007

This is the third of four “Point‐Counterpoint” articles planned to appear in this column. These articles are based on discussion sessions held at the Sixth National Aquifer Restoration and Ground Water Monitoring Conference. A brief article outlining each speaker's opinion is offered first, followed by the transcript of the discussion session during which attendees have a chance to ask the speakers quesions on the subject.
Chlorine Disinfection of Ground Water Obtained from 200M Deep Wells
Authors: Wickramanayake G.B. , Rajput V. S. , Polprasert C.
Published: February 2007

The effect of chlorine concentration, ground water pH, and contact time on chlorine demand and the inactivation of coliform bacteria, Escherichia coli, was studied in the laboratory using a batch reactor under controlled environmental conditions. Ground water for this study was obtained from 200m deep wells in Bangkok, Thailand. The test results demonstrate that the kinetics of chlorine inactivation of coliforms in ground water consist of an initial rapid kill rate followed by a slower rate. Disinfection was more effective in acidic pH (5.5) than basic pH (8.5). Chlorine demand exerted by ground water increased with chlorine dose, contact time, and hydrogen ion concentration. Based on the applied chlorine dose, inactivation of E. coli by chlorine at neutral pH and room temperature was over two orders of magnitude less effective in ground water than in demand‐free water. Because of the high chlorine demand exerted by this ground water, chlorine residuals leaving the treatment plant are likely to be unstable.
Vadose Zone Characterization of Low‐Permeability Sediments Using Field Permeameters
Authors: Stephens Daniel B. , Unruh Mark , Havlena Jeff , Knowlton Robert G. , Mattson Earl , Cox Warren
Published: February 2007

Measurement of the saturated hydraulic conductivity of material in the unsaturated zone beneath proposed surface impoundments is important for predicting seepage rates of water and contaminants. Hazardous waste disposal facilities are commonly sited on the basis of the low permeability of the geologic materials beneath the site. Field measurement of the saturated hydraulic conductivity of low‐permeability materials may be accomplished using air‐entry permeameters and borehole permeameters. The results of a coordinated field and laboratory investigation of low‐permeability materials at a hazardous waste facility are presented. The different methods of testing and analysis are compared and discussed. In general, air‐entry permeameters and borehole permeameters are useful for measuring the saturated hydraulic conductivity of low‐permeability materials.
A Three‐Dimensional Analytical Model to Aid in Selecting Monitoring Locations in the Vadose Zone
Authors: McKee C. R. , Bumb A. C.
Published: February 2007

Monitoring of the vadose zone is a potentially complex, time‐consuming, and expensive problem. The location of monitoring points and selection of monitoring instruments can be optimized by using computer models. Numerical models developed for this purpose in the past have often been expensive and difficult to use. This paper describes a fast, three‐dimensional, approximate analytical solution to the moisture content in the unsaturated zone. An analytical solution is available for steady‐state drainage, whereas an approximate analytical solution is available for the transient case. The model will handle an arbitrary distribution of fluid sources, as well as vertical and horizontal impermeable boundaries.

The model may be applied to predict the incursion of fluid from accidental leakage or infiltration over large areas from unlined ponds and land treatment sites. The model is quite useful as an aid in designing monitoring or premonitoring programs near hazardous waste sites. Examples are presented to demonstrate the model's utility in estimating the maximum spread of a contaminant, the extent to which the fluid may spread with depth, the regions of high and low capillary pressure, and the non‐linear behavior of the saturation when drainage from several sources in considered. These results are useful for the placement of monitoring locations and the selection of appropriate instruments, and as a tool in working with regulatory agencies to design monitoring programs. A glimpse of the future is necessary for today's planning. Computer models are some of the most useful crystal balls we have available.
Use of Total Organic Carbon as an Indicator of Contamination from an Oil Refinery, South‐Central Kansas
Authors: Spruill Timothy B.
Published: February 2007

Water samples collected from 26 sites at an abandoned oil refinery in south‐central Kansas were analyzed for total organic carbon (TOC) and specific volatile and semivolatile organic compounds by gas‐chromatography/mass‐spectrometric methods. Results from a Spearman‐rho correlation analysis between TOC concentration and the number of compounds (correlation coefficient = 0.71) and TOC concentration and total concentration of compounds identified (correlation coefficient = 0.83) indicate correlations significant at the 0.01 level.

Although TOC data alone would not be sufficient to evaluate hazards posed by oil‐refinery wastes, results of the correlation analysis performed using data collected from the site in Kansas indicate that TOC data can be used effectively to delineate petroleum‐related ground water contamination and to help identify sources of ground water contaminants. TOC data collected from a large number of temporary sampling points during the initial phases of an investigation will provide an estimate of the extent of hydrocarbon contamination and allow placement of monitoring wells and more detailed sampling in appropriate areas.
An Inexpensive, Multi‐Use, Dedicated Pump for Ground Water Monitoring Wells
Authors: Ronnie E.H. , Nadon R.L.
Published: February 2007

A simple, inexpensive sampling pump has lately come into use in ground water monitoring. The pump is referred to as an inertial pump; its only downhole components are a foot valve connected to a length of tubing or pipe. The operating principle of the pump is based on the inertia of a column of water within the riser tubing. Ground water is drawn through the foot valve and up the riser tubing by rapid up and down movements of the tubing. This pumping method is not new, but has only recently been applied to monitoring wells. Foot valves are available in a variety of materials and sizes and can be used in monitoring wells as small as 19mm (3/4 inch) I.D. Flexible polyethylene or Teflon® tubing, and in some cases stainless steel tubing or rigid PVC pipe, is used as the riser. The inertial pump satisfies most of the criteria normally cited for an “ideal” sampling device. The pump is easy to operate, reliable, durable, portable, and virtually maintenance‐free. It can be operated manually from as deep as 40m or from as deep as 60m using a motor drive. The pump is inexpensive, and therefore suitable for use as a dedicated sampling pump. Recent tests have shown the pump to be suitable for sampling volatile organics. The inertial pump has a high flow capacity and performs well in silty/sandy environments, which makes it useful for developing and purging monitoring wells. It may also be used to perform field hydraulic conductivity tests.
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

Enhanced 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

On‐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.