Appearance on this list is not to be construed as an endorsement by any regulatory agency nor is it any guarantee of the performance of the method or equipment. Equipment should be installed and operated in accordance with all applicable laws and regulations.
Leak Threshold. Pipeline Capacity. Maximum of , gallons. Waiting Time. None between delivery and testing. Test Period. They exposed the biosensor system to a series of organic compounds catechols, chlorophenols, biphenyl that are structurally related to chlorocatechols and might interfere with the biosensor system.
No appreciable levels of b-galactosidase were produced. The UK scientists have also demonstrated that the system is capable of distinguishing 3-chlorocatechol from 4-chlorocatechol.
This biosensor system is a probe tailor-made to directly monitor the level of chlorocatechols in soil, sediment, and water samples at Superfund sites.
Because it does not require expensive equipment or extensive pretreatment of environmental samples, the UK biosensor system is simpler and more economical than standard methods. The UK scientists are working to develop additional biosensor systems. By using different reporter proteins that emit fluorescence or bioluminescence at different wavelengths, they are developing array sensing systems for a variety of environmental pollutants.
Analysis of the color of the light generated by the bacteria will allow for identification of the pollutant s present in a particular environment. This would provide tools for in situ monitoring of multiple contaminants at Superfund sites. Contact: Sylvia Daunert, Dept. Zelt; A. Levander; D.
Dana; I. Morozov; B. Magnani, Rice Univ. Eos Trans. AGU, 81 48 , Fall Meet. As part of an ongoing environmental characterization project at Hill Air Force Base near Ogden, Utah, a 3-D seismic survey was performed over a contaminated aquifer in July and August The aquifer is bounded below by a clay aquiclude, in which a paleochannel acts as a trap for the contaminants.
The overburden consists of Quaternary sands, gravels and clays. Imaging the structure of the paleochannel at depths up to 15 meters was the main target of the survey. The experiment included 3-D reflection, 3-D refraction, checkshot surveys, and vertical seismic profiles in wells up to 15 meters deep. Preliminary traveltime tomography results from the 3-D tomography and reflection surveys are presented. For the tomography experiment, the entire site approximately 95 meters by 36 meters in area was surveyed with about RefTek Texan recorders deployed in a stationary rectangular grid having an inline spacing of 2.
A shot from a. The source provides a broad frequency range from 40 Hz to greater than Hz. The 2-D data and the synthetic tests suggest that the 3-D wide-angle data will provide a well-resolved 3-D velocity model of the paleochannel using first-arrival tomography. Levander; I.
Morozov; C. Zelt; B. The survey target is a paleochannel buried beneath Quaternary sands, gravels and clays that acts as a local trap for contaminants. The highly irregular, steep walled paleochannel was imaged by a pilot 2-D survey conducted in , demonstrating the viability of seismic methods for investigating the upper 20m at this site. The four week experiment included 3-D seismic reflection, 3-D tomography, six check shot surveys in 15m boreholes for velocity estimation, and two vertical seismic profiles.
A rifle was used as the seismic source in all experiments, producing frequencies from 40Hz to greater than Hz. Approximately shot records were taken in the various experiments; the experiment at times generated 9Gbytes of data per day. The 3-D reflection and tomography experiments both occupied an area of 95m by 36m, and utilized over RefTek Texan instruments.
For the reflection experiment the instruments were deployed in swaths of six receiver lines 2. The shot pattern was a rotated brick pattern with 0. Data quality appears to be excellent, despite a high level of cultural noise.
The shot gathers show strong reflections with conflicting dips, characteristic of steeply dipping features. Alumbaugh Univ. Yeh Univ. During cleanup or immobilization of vadose zone contamination that has occurred through free release of wastes on the surface or by leaking landfills and storage tanks, new and innovative long-term vadose zone monitoring techniques are needed to track hydrologic conditions and provide information on important flow and transport processes.
The researchers have focused on developing, implementing, and testing a new approach that synthesizes a recently developed inverse hydrologic modeling technique with state-of-the-art geophysical sensing technologies.
The result is a robust method for characterizing, monitoring, and predicting fluid movement in heterogeneous vadose zones.
Pirestani, K. Imhoff, Univ. Partitioning tracer tests PTTs are an innovative technology used for the detection and subsurface distribution estimation of nonaqueous phase liquids NAPLs. The PTT involves injecting a tracer pulse of partitioning and nonpartitioning tracers into an aquifer with subsequent measurement of the tracer concentrations in extraction wells.
The partitioning tracer is retarded or slowed when it partitions into the NAPL. The amount of retardation is proportional to the saturation of NAPL in the porous media. Column experiments were performed to determine the minimum contact time between tracer solutions and rectangular micropools of trichloroethylene TCE for detection of all TCE.
Different contact times were achieved by flushing tracer solutions of different volumes with different flushing velocities. The TCE micropools were centimeters in size and reflect the small volumes that may be trapped by textural heterogeneities in some subsurface systems.
The length and thickness of the TCE micropools were varied to create different required equilibration times. The results from these experiments were put in dimensionless form and used to explore relationships between the size of NAPL micropool and the necessary contact time between tracer solution and micropool for NAPL detection.
This reference manual is for State and EPA regulators, especially inspectors of USTs, knowledgeable UST owners and operators wanting to compare specifications for various leak detection devices, and vendors of UST leak detection systems. This reference manual contains a summary of specifications, based on third-party evaluations, for over systems that detect leaks from USTs and their piping. Approval or acceptance of leak detection systems is the responsibility of the implementing agency--in most cases the State environmental agency.
The lateral extent of the electrically conductive portion of the contaminant plume emanating from the Norman Landfill was mapped using electrical geophysical measurements. EM induction and DC resistivity methods measured the apparent electrical resistivity of the subsurface.
Both methods show an area of low resistivity indicating poor ground-water quality in the alluvium, presumably due to leachate from the Norman Landfill. This area extends from the southwest side of the main landfill mound toward the Canadian River for no more than about meters.
Cross section and depth-slice maps made from the interpretation of the DC resistivity soundings and maps of measured resistivity from the EM measurements illustrate the lateral extent of the landfill contamination and show that the contaminate plume, which is about 9 meters thick, does not appear to extend into the bedrock. The EM induction method proved to be an easy and efficient procedure for rapidly determining the lateral extent of the leachate plume.
The DC resistivity method, although more time consuming, provided better vertical resolution of the resistivity distribution. Fitterman; R. Geological Survey Open-File Report , p 40, At Silverton, SIP measurements were made at intervals of 1. The study results suggest that the acid waters currently draining from the Mayday mine dump probably result mainly from process es involving already-oxidized minerals, rather than from primary oxidation of sulfides at grain surfaces.
Grimes; Robert O. Geological Survey Open-File Report , [16 pp], An understanding of the fate of cyanide CN- in mine process waters is important for addressing environmental concerns and for taking steps to minimize reagent costs. The utility of stable isotope methods in identifying cyanide loss pathways has been investigated in case studies at three Nevada gold mines.
Pregnant solutions returning from ore heaps display small isotopic shifts to lower 15N and 13C values. The shifts are similar to those observed in laboratory experiments where cyanide was progressively precipitated as a cyanometallic compound, and are opposite in sign and much smaller in magnitude than the shifts observed in experiments where HCN was offgassed.
Offgassing is inferred to be a minor cyanide loss mechanism in the heap leach operations at the three mines, and precipitation as cyanometallic compounds, and possibly coprecipitation with ferric oxides, is inferred to be an important loss mechanism.
Isotopic analysis of dissolved inorganic carbon DIC shows that uptake of high d13C air CO2 has been important in many barren and pregnant solutions.
Overall, isotope data provide quantitative evidence that only minor amounts of cyanide are lost via offgassing and that significant amounts are destroyed via hydrolysis and related pathways. The data also highlight the possibility that significant cyanide may be either retained in the ore heaps or destroyed via other chemical pathways.
Clark; K. Livo; R. Kokaly; B. Rockwell; J. The principal elements of this joint investigation include mapping and characterization of surficial minerals, watershed evaluation to better define effects of mineralization and related mining activities, and vegetation studies. Geological Survey Open-File Report , In addition, the traces and the travel times can be plotted on the computer screen or printed to a file in postscript format. The program is written in the IDL programming language, and it is executed, in command-line mode, within the IDL program.
The IDL program must be run from an X-window terminal that is connected to a computer with the Unix operating system. The data must be in the SU format. Pamukcu; Horace Moo-Young, Dept. Nuclear magnetic resonance response measurement is a nondestructive and nonintrusive technique that is potentially useful for in situ characterization and mapping of hydrocarbon contamination in the subsurface, including rock.
Magnetic resonance measurements of a porous medium allow the determination of necessary parameters to evaluate permeability and porosity of the medium and the type of hydrocarbons present in the pore fluid. This paper presents the results of a preliminary study intended to evaluate the robustness of the magnetic resonance imaging technology using well-characterized laboratory specimens of porous material containing hydrocarbon liquids. The porous materials tested were 1 a dry uniform sand pack impregnated with an aqueous coal tar mixture and 2 packed columns of glass beads of various sizes permeated with distilled water and trichloroethylene.
The discernable images of the pore space and the interface of the two liquids in the pore space indicated that magnetic resonance imaging could be a viable tool to determine spatial distribution and mass fraction of hydrocarbon liquids in subsurface contamination. Thurman; K. Semipermeable membrane devices SPMDs passively accumulate hydrophobic organic compounds when placed in water. The devices consist of a low-density polyethylene LDPE lay-flat membrane filled with 1 gram of a high molecular weight lipid, triolein, that cannot diffuse through the membrane.
The LDPE membrane mimics a biological membrane in its ability to allow selective diffusion of organic compounds. From SPMDs placed in five Mississippi Delta streams in and , the persistent organic pollutants aldrin, chlordane, DCPA, DDT, dieldrin, endrin, heptachlor, hexachlorobenzenes, mirex, nonachlor, and toxaphene were detected, in addition to two insecticides still in use, the organophosphate chlorpyriphos and the organochlorine endosulfan.
Two low-solubility herbicides not seen commonly in surface water, pendimethalin and trifluralin, also were detected. Nietch; James T. Proceedings of the U. Volume 3 of 3: Subsurface Contamination from Point Sources. The purpose of this investigation was to determine whether tree-core analysis could be used to delineate shallow ground-water contamination by chlorinated ethenes.
Analysis of tree cores from baldcypress, tupelo, sweetgum, oak, sycamore, and loblolly pine growing over shallow ground water contaminated with cis-1,2-dichloroethene cDCE and trichloroethene TCE showed that those compounds also were present in the trees. The cores were collected and analyzed by headspace gas chromatography. Baldcypress, tupelo, and loblolly pine contained the highest concentrations of TCE, with lesser amounts in nearby oak and sweetgum.
The concentrations of cDCE and TCE in various trees appear to reflect the configuration of the chlorinated-solvent ground-water contamination plume. Baldcypress cores collected along The ability of the tested trees to take up cDCE and TCE make tree coring a potentially cost effective and simple approach to optimizing well placement at this site.
ISBN: Geotechnical Special Publication No 71, p , The use of dielectric constant and electrical conductivity of the soil-fluid system has been suggested to overcome deficiencies of current identification and characterization methods. However, little is known about the dielectric behavior of a contaminated soil-fluid system. The authors describe a study undertaken to investigate the possibility of using dielectric constant and electrical conductivity to characterize and identify contaminated fine-grained soils.
The dielectric constant and electrical conductivity of kaolinite, bentonite, and local soil were determined at various ion concentrations, organic liquids, and moisture content. Results showed both dielectric constant and electrical conductivity of the soil-fluid system to be mainly controlled by pore fluid. Modern Geophysics in Engineering Geology. Geological Society, London. Geological Society Engineering Geology special publication, ; no 12, p , This paper describes a strategy for characterizing contaminated bedrock aquifers using borehole geophysics and multilevel wells that greatly increases the chances of success.
Although these methods can be expensive, proper application may reduce long-term monitoring costs. The case study site is a hilltop landfill overlying a heterogeneous bedrock aquifer and surrounded by homes using domestic wells. Borehole geophysical and heatpulse-flowmeter data identified the number of water-bearing zones WBZs per 30 meters drilled.
Multilevel wells focused sampling on WBZs and provided detailed plume characterization and monitoring to help protect local domestic wells. A review of logs from one monitoring well shows how borehole geophysics identified seven individual WBZs, and sampling of the multilevel well revealed important variations in chemical and potentiometric signatures between the WBZs. This detailed characterization supported the site conceptual model and demonstrated that domestic wells were not threatened.
The increasing use of low-flow sampling techniques and the rising popularity of monitored natural attenuation remedies should lead to increased application of this strategy.
Geotechnical Special Publication No. XRF is not intended to replace the more rigorous laboratory-based analysis for regulatory purposes. Rather, XRF provides near real-time data to produce a contaminant distribution map while the crew is in the field, without relying on time consuming and costly laboratory analysis to complete the distribution picture. XRF analysis allows better delineation of contaminant distribution by providing higher data density in a time- and cost-effective manner.
The Navy has developed a rapid bioassay system QwikSed that is proving to be a valuable asset for conducting bioassays on marine sediments. The basis of detection is to measure a reduction in light from a bioluminescent dinoflagellate such as Gonyaulux polyedra or Ceratocorys horrida following exposure to a toxicant.
The toxic response is usually measured within 24 hours from the start of the test and can be conducted for a 4-day acute test or a 7- to day chronic test. A measurable reduction or inhibition in bioluminescence is an adverse effect. Lauderdale, Florida. The instrument includes built-in software that automatically prints the raw data and calculates the mean, standard deviation, coefficient of variation, percent of control, and the estimated IC The QwikSed unit can be connected to either a printer via a serial port on the back of the unit for direct printouts, or it can be connected to a computer for further manipulation or graphing of data using a software program such as Excel.
The enzyme-linked immunosorbent assay ELISA is used for environmental field analysis because it can be optimized for speed, sensitivity, and selectivity, has a long shelf life, and is relatively simple to use. Immunoassay tests use antibodies to bind with a target compound or class of compounds, in this case PCBs. Concentrations of the PCB and the target analyte are identified through a colorimetric reaction.
The determination of PCBs presence is made by comparing the color developed by a sample of unknown concentration with the color formed by the standard containing the analyte at a known concentration. The concentration of the PCB is determined by the intensity of color in the sample and is measured with a spectrophotometer. Immunoassay kits are relatively quick and simple to use with a short training session. Detection limits can vary depending on the dilution series used.
The detection limit for PCBs test kits in soil ranges from 50 to ppb. RPM News, p , Spring An innovative field-screening method is available to profile soil conductivity and volatile organic compounds VOCs in soil and ground water. The technique provided real-time results, which assisted in the selection of optimal soil and ground-water sampling locations, thereby reducing the overall number of samples required.
Soil and ground-water contamination originated from previously leaking pipes associated with underground storage tanks USTs located at the Navy Exchange Gas Station.
Ground-water contamination migrated downgradient, and despite a remedial action to treat both soil and ground water, legacy contamination remains in relatively low-permeability soil approximately to feet from the source area. Using direct push technology DPT , the 1. The VOCs diffuse across a membrane and into a carrier gas. The gas is then analyzed, using a combination of a flame ionization detector FID , a photo ionization detector PID , and an electrical conductivity detector ECD for chlorinated VOCs only in a laboratory-grade gas chromatograph at the surface.
The SC portion of the system uses a dipole measurement arrangement in which an alternating current is passed from the center of the probe to the probe body. The voltage response of the soil to the current is measured across these same two points. Lower conductivities indicate sands high-permeability material , while higher conductivities indicate silts and clays low-permeability material. The continuously measured results are captured by data-logging software and displayed in real time as the probe is advanced.
At the Athens site, the soil conductivity results with the MIP results indicate that the plume is being contained in place by low-permeability soil. RPM News, p 10, Spring A recently implemented innovative technology is capable of continuously measuring air permeability as well as contaminant concentration along a well screen during soil vapor extraction SVE. The technology can be used to assess remediation progress and provide data to help optimize the efficiency of the existing system.
An SVE system had been installed late in and had worked effectively for more than six months. The probe continuously measures contaminant concentration and airflow along the entire well screen length. Soil vapor flow measurements are performed using a downhole flowmeter. VOC measurements are made using a photoionizing detector.
The contaminant concentration profiles are calibrated with off-site analyses of vapor samples collected from the well head. The airflow data showed no areas of restricted airflow, proving that the existing system was operating effectively. The contaminant concentration profiles confirmed that there were no individual pockets of high concentrations of TCE along the well screen. Additionally, the concentration data demonstrated that the highest concentrations were measured close to ground water and were a result of offgassing from the contaminated ground water.
The data it produces are not only useful for SVE optimization, but can also be used for soil venting design, risk assessments, and accelerated site characterization. Demers; R. Geotechnical Special Publication No , p , Remote sensing technologies coupled with ongoing and planned remote sensing can be used to generate hydrologic data at spatial, temporal, and spectral resolutions never previously available.
Artificial neural networks ANNs are being developed to characterize, model, and predict complex multisource remotely sensed hydrologic data. The authors review and examine the utility of ANNs for hydrologic applications, with particular emphasis on remote sensing of precipitation, soil moisture, and multisource land surface data. Recurrent neural networks are reviewed in addition to more popularly used multilayer feedforward networks for prediction and self-organization neural networks in spatial characterization of heterogeneous land surface processes.
Zweifel; A. Moens; R. McLeod; M. Nishikawa [et al. Wonder U. DOE Ames Lab. Benson Technos Inc. Yuhr Technos Inc. Bevolo U. Geophysical techniques were successfully incorporated into an ESC project at an oil seepage basin site on DOE's Savannah River site to define the limits of buried wastes, detect and map an inorganic plume emanating from the waste trenches, and define the approximate depth and lateral continuity of major stratigraphic units across the site.
When integrated with minimally intrusive direct push technologies, the geophysical techniques provided the framework for the development of the conceptual site model. The refined model was then used to guide ground-water contaminant sampling to define the spatial extent of the inorganic and organic plume emanating from the waste trenches.
McKinney; Gary A. ISBN: , p , Carpenter; J. ISBN: X. Gassman; M. Hanif Chaudhry, Dept. The authors describe the use of the frequency response method to determine the location and rate of leakage in open loop piping systems. A steady-oscillatory flow, produced by the periodic opening and closing of a valve, was analyzed in the frequency domain by using the transfer matrix method, and a frequency response diagram at the valve developed.
In a leaking system, this diagram has additional resonant pressure amplitude peaks that are lower than the resonant pressure amplitude peaks for the system with no leaks. Several piping systems have been successfully analyzed for all practical values of the friction factor to detect and locate individual leaks of up to 0.
The method requires the measurement of pressure and discharge fluctuations at only one location and has the potential to detect leaks in real-life pipe systems conveying different types of fluids, such as water and petroleum. Test Period. Minimum of 3 hours, 10 minutes after setup and after pipeline is fully isolated.
Test data are acquired and recorded by a microprocessor. Calculations are automatically performed by the microprocessor. System Features. System may be permanently installed on pipeline to perform monitoring, or may be transported and set up to perform line tightness testing.
A single 3-hour minute test is required consisting of a 1-hour minute monitoring period at operating pressure, and a 2-hour monitoring period at atmospheric pressure. Leak Threshold. A pipeline system should not be declared tight if the test result indicates a loss that equals or exceeds these thresholds. Gasoline, diesel, aviation fuel, fuel oil 4.
System tests fiberglass or steel piping. Tests are conducted at operating pressure to a maximum of psi. Pipeline Capacity. Maximum of , gallons.
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