ISSN:1069-3629    

DOI:10.1111/j.1745-6592.1995.tb00515.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:1069-3629    

DOI:10.1111/j.1745-6592.1995.tb00516.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:1069-3629    

DOI:10.1111/j.1745-6592.1995.tb00517.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:1069-3629    

DOI:10.1111/j.1745-6592.1995.tb00518.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:1069-3629    

DOI:10.1111/j.1745-6592.1995.tb00519.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractVolatile organic compounds delected in ground water from wells at Test Area North (TAN) at the Idaho National Engineering Laboratory (INEL) prompted RCRA facility investigations in 1989 and 1990 and a CERCLA‐driven RI/FS in 1992. In order to address ground water treatment feasibility, one of the main objectives, of the 1992 remedial investigation was to determine the vertical extent of ground water contamination, where the principle contaminant, of concern is trichloroethylene (TCE). It was hypothesized that a sedimentary interbed at depth in the fractured basalt aquifer could be inhibiting vertical migration of contaminants to lower aquifers. Due to the high cost of drilling and installation of ground water monitoring wells at this facility (greater than $100,000 per well), a real time method was proposed for obtaining and analyzing ground water samples during drilling to allow accurate placement of well screens in zones of predicted VOC contamination. This method utilized an inflatable pump packer pressure transducer system interfaced with a datalogger and PC at land surface. This arrangement allowed for real lime monitoring of hydraulic head above and below the packer to detect leakage around the packer during pumping and enabled collection of head data during pumping for estimating hydrologic properties. Analytical results were obtained in about an hour from an on‐site mobile laboratory equipped with a gas chromalograplvmass spectrometer (GC/MS). With the hydrologic and analytical results in hand, a decision was made to either complete the well or continue drilling to the next test zone. In almost every case, analytical results of ground water samples taken from the newly installed wells closely replicated the water quality of ground water samples obtained through the pump packer sys

ISSN:1069-3629    

DOI:10.1111/j.1745-6592.1995.tb00520.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe impact of lost circulation during rotary drilling near an existing monitoring well cluster was evaluated by periodic measurements of water levels and contaminant concentrations at the well cluster. Due to regulatory concerns, changes in water levels or VOC concentration in the well cluster during drilling would trigger monitoring well redevelopment. The borehole was drilled approximately 30 feet northeast of four nested monitoring wells that screen Devonian and Silurian carbonate bedrock at depths of 15, 60, 130, and 190 feet. Following complete circulation loss at depths of 177 and 1 S3 feet in the borehole, a rapid decrease in water levels was observed in the upper three monitoring wells. The water level in the well that was screened through the lost circulation zones increased slightly.Decreasing water levels in formations located above the point of circulation loss appear to occur in response to a sudden decrease in borehole fluid pressure caused by the flow of drilling fluid into the formation. The relative contribution of contaminated formation water lo the borehole can be estimated by using the time‐drawdown relationship and estimates of transmissivity. At the point of circulation loss, significant dilution of contaminant concentrations occurs from the loss of drilling fluid into the contaminated zone. Contaminated formation water entering the borehole during periods of complete lost circulation may mobilize contaminants from upper lo lower formations. Lost circulation into a formation would be signaled by a water level increase in monitoring wells. The wells would subsequently require development to remove the volume of fluid lost to the formation, including both drilling fluid and contaminated formation water. Monitoring wells exhibiting declining water levels following lost circulation would not require development since drilling water has not entered the zones screened by these well

ISSN:1069-3629    

DOI:10.1111/j.1745-6592.1995.tb00521.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractEvidence for the natural microbial remediation of subsurface fuel contamination situations should include identification and analysis of transformation or degradation products. In this way. u mass balance between fuel constituents and end products may be approached to monitor cleanup progress. Application of advanced organic acid metabolite derivatization techniques to several known sites of organic compounds and fuel mixture contamination provide valuable information on the pathways and progress of microbial transformation. Good correlation between observed metabolites and transformation pathways of aromatic fuel constituents were observed at the sites.

ISSN:1069-3629    

DOI:10.1111/j.1745-6592.1995.tb00522.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractThe need 10 characterize deep and shallow bedrock hydrogeologic conditions in remote terrain encouraged the development of an inexpensive, last, and easily transporrable double packer sampler. The principal objective was to combine water sampling and hydraulic measurement with the same equipment. Unconventional construction that does not create any large hydraulic pressure differences in the equipment allows light and inexpensive standard materials and components to be used. The low cost, lightweight equipment can thus be operated by a single person.The equipment is based on the principle of using soft, hydraulically expandable packers that isolate the required section of the borehole. The inflation and deflation of the packers is controlled by a single tube, through which the water sample is also withdrawn. The uppermost part of the tube branches into two tubes; the pumping action is generated by cyclic pressure pulses applied to one of these tubes.The equipment has mainly been used in narrow 1,8‐inch (46 mm) diameter boreholes down to a depth of about 3280 feet (1000 m); versions capable of operating in larger boreholes and with higher pump capacity have also been constructed. At one sampling site, the chemical composition of water from an isolated fracture zone was compared with open hole water at the same depth. The water from the fracture had a different chemical composition compared with the mixed water sample from the open hole. To collect representative ground water samples, double packers and long pumping limes are required.The equipment characterizes both the hydraulically conductive bedrock structures and the chemical compositions of bedrock ground water. Through comparison to K‐values and chemical constituents in other portions of the borehole, the collected data can be used to estimate transport pathways, aquifer yield, travel times, and ground water evolution. The range of hydraulic conductivity measured with the equipment in association with this research was 10‐10to 10

ISSN:1069-3629    

DOI:10.1111/j.1745-6592.1995.tb00523.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

AbstractStiff diagrams arc a multivariate method of analysis used to describe the chemical state of ground water. The use of Stiff diagrams to describe multiconstituent contamination sites, such as landfills, has distinct advantages over single constituent analyses. Problems associated with traditional Stiff diagram analyses, such as diagram attentuation, can be addressed by allowing the scale of the diagram to vary with the ionic strength of the analyzed sample. The use of these sliding scale Stiff diagrams reveals the chemical slate of the ground water over wide ranges of constituent concentrations and thus allows for sensitive and sophisticated depictions of complicated contamination sites in a fashion that is extremely difficult to replicate with single constituent analyses. This approach has possible applications for understanding and tracing the mixing and chemical changes in uncontaminated settings.

ISSN:1069-3629    

DOI:10.1111/j.1745-6592.1995.tb00524.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY