Groundwater Monitoring & Remediation最新文献

{"title":"222Rn as Natural Tracer for LNAPL Recovery in a Crude Oil‐Contaminated Aquifer","authors":"V. Ponsin, Amélie Chablais, Julien Dumont, O. Radakovitch, P. Höhener","doi":"10.1111/gwmr.12091","DOIUrl":"https://doi.org/10.1111/gwmr.12091","url":null,"abstract":"The objective of this study was to investigate whether 222Rn in groundwater can be used as a tracer for light non‐aqueous phase liquid (LNAPL) quantification at a field site treated by dual‐phase LNAPL removal. After the break of a pipeline, 5 ha of soil in the nature reserve Coussouls de Crau in southern France was contaminated by 5100 m3 of crude oil. Part of this oil seeped into the underlying gravel aquifer and formed a floating oil body of about 3.9 ha. The remediation consists of plume management by hydraulic groundwater barriers and LNAPL extraction in the source zone. 222Rn measurements were performed in 21 wells in and outside the source zone during 15 months. In uncontaminated groundwater, the radon activity was relatively constant and remained always >11 Bq/L. The variability of radon activity measurements in wells affected by the pump‐and‐skim system was consistent with the measurements in wells that were not impacted by the system. The mean activities in wells in the source zone were, in general, significantly lower than in wells upgradient of the source zone, owing to partitioning of 222Rn into the oil phase. The lowest activities were found in zones with high non‐aqueous phase liquid (NAPL) recovery. LNAPL saturations around each recovery well were furthermore calculated during a period of high groundwater level, using a laboratory‐determined crude oil–water partitioning coefficient of 38.5 ± 2.9. This yielded an estimated volume of residual crude oil of 309 ± 93 m3 below the capillary fringe. We find that 222Rn is a useful and cheap groundwater tracer for finding zones of good LNAPL recovery in an aquifer treated by dual‐phase LNAPL removal, but that quantification of NAPL saturation using Rn is highly uncertain.","PeriodicalId":158105,"journal":{"name":"Groundwater Monitoring & Remediation","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114533880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and Implementation of a National Groundwater Monitoring Network","authors":"M. Wireman","doi":"10.1111/GWMR.12105","DOIUrl":"https://doi.org/10.1111/GWMR.12105","url":null,"abstract":"","PeriodicalId":158105,"journal":{"name":"Groundwater Monitoring & Remediation","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130537793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resurgence of Pump and Treat Solutions: Directed Groundwater Recirculation","authors":"S. Suthersan, Eric Killenbeck, S. Potter, C. Divine, Michael LeFrancois","doi":"10.1111/gwmr.12114","DOIUrl":"https://doi.org/10.1111/gwmr.12114","url":null,"abstract":"Summary and Conclusions DGR is an effective technology to enhance aquifer flushing mechanisms to address complex contaminant distri-bution resulting from varying hydrau-lic conditions an aquifer experiences during decades-long propagation and development of large diffused plumes. The dynamic and adaptive implementa-tion of DGR allows for the CSM and system performance data to guide the process of system design, implementa-tion, and operation. As a summary, key steps and considerations for effective design and application of DGR include:• Use a quantitative model for the initial design to minimize flushing times between injection and extrac-tion wells and limit hydraulic dead zones. Test alternate flow rates to understand flow field changes asso-ciated with changes in flow for the selected well layout.• During system installation and start up, conduct hydraulic testing to confirm local hydraulic conductiv-ity, well performance, and contami-nant distribution.• Focus on system evaluation and adaptive optimization to achieve target flow rates, expected mass removal rates, and not just on the “capture zones.”• Emphasize extraction well location within the highest permeability zones that can most effectively access contaminant mass with the highest migration potential. In some cases contaminant mass recovery rates at these wells can temporarily increase in the short term as the well increasingly captures water from higher concentration zones. In particular, this response may be observed in fractured rock sites.• Evaluate system performance con-tinuously by tracking well-specific and total system contaminant mass removal rates against total volume","PeriodicalId":158105,"journal":{"name":"Groundwater Monitoring & Remediation","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125429635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Investigation of the Pressure Pulsing Reagent Delivery Approach","authors":"T. Gale, N. Thomson, J. Barker","doi":"10.1111/gwmr.12102","DOIUrl":"https://doi.org/10.1111/gwmr.12102","url":null,"abstract":"Pressure pulsing technology is an innovative method that has been developed with the aim of overcoming preferred flow paths associated with remediation techniques that rely on the injection of reagents. Numerical and field experiments were conducted to assess how pressure pulsing affects groundwater flow and solute transport during reagent injection. A series of field experiments were performed at two field sites where a monitoring network designed to capture the breakthrough of solutes delivered from an injection well was installed. Pressure pulsing and conventional injection methods were used at each site. One site was comprised of fine sand with low heterogeneity, while the other was moderately heterogeneous with discrete layers varying from fine sand to silt. The data suggest that breakthrough was more uniform for the pressure pulsing injections; however, this difference was minor and complicated by sorption of some of the tracers employed. The groundwater flow and solute transport modeling exercise simulated the rapid boundary pressure modulation that occurs in association with pressure pulsing. Two‐dimensional (2D) simulations revealed that repeated sudden onset of injection cessation produces brief periods of gradient reversal and the development of a mixing zone near the injection well. The spatial extents of this mixing zone were found to be highly dependent upon the hydraulic diffusivity of the medium, with medium heterogeneity and pulsing frequency playing secondary roles. Three‐dimensional (3D) numerical simulations were used to benchmark the observations from one of the field sites. The results from the modeling effort showed that solute breakthrough from a pressure pulsing injection is more dispersed relative to a conventional injection as a result of the mixing zone phenomenon; however, we were unable to directly observe this mixing zone using the instrumentation deployed at the two field sites.","PeriodicalId":158105,"journal":{"name":"Groundwater Monitoring & Remediation","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123810047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and Testing of a Field Screening Method Based on Bubbling Extraction and Photoionization Detection for Measurement of Benzene and Total VOCs","authors":"Catalina Espino Devine, P. Bennett, K. Synowiec, S. Nelson, Rachel E. Mohler, M. Einarson","doi":"10.1111/gwmr.12070","DOIUrl":"https://doi.org/10.1111/gwmr.12070","url":null,"abstract":"A field screening method was developed for rapid measurement of benzene and gasoline range total petroleum hydrocarbons (TPHg) concentrations in groundwater. The method is based on collecting photoionization detector (PID) measurements from vapor samples. The vapor samples are collected by bubbling air through groundwater samples (air sparging) with a constant volume, temperature and sparging rate. The level of accuracy, sensitivity, precision, and statistical significance of the estimated concentrations, derived from the screening method, are comparable to conventional laboratory analytical results at concentrations equal to or greater than 150 µg/L for benzene and greater than 50 µg/L for TPHg. The method's concentration estimations can assist in making real‐time decisions regarding location of dissolved plumes and light nonaqueous phase liquid (LNAPL) source zones at many fuel release sites. The screening method was tested in the laboratory and in the field with 208 and 107 samples, respectively. The study concludes that the screening method can be used as a tool to aid in completing a site conceptual model as well as analyzing groundwater from monitoring wells.","PeriodicalId":158105,"journal":{"name":"Groundwater Monitoring & Remediation","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120676655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Method for Assessing Source Zone Natural Depletion at Chlorinated Aliphatic Spill Sites","authors":"Ryan Ekre, Paul C. Johnson, B. Rittmann, R. Krajmalnik-Brown","doi":"10.1111/gwmr.12049","DOIUrl":"https://doi.org/10.1111/gwmr.12049","url":null,"abstract":"This work focuses on the site‐specific assessment of source zone natural attenuation (SZNA) at chlorinated aliphatic hydrocarbon (CAH)‐impacted sites. The approach is similar in some ways, but different in other ways from recently proposed SZNA assessment paradigms for petroleum‐impacted sites. The similarities lie in the organization of the approach around determining: (1) whether or not SZNA is occurring, (2) the current SZNA rate, and (3) what is the future projection for SZNA rate changes and the final state of the source zone. Differences lie in how those rates are determined, especially with respect to the quantities measured and data reduction. Petroleum‐impacted site SZNA approaches emphasize quantifying fluxes of electron acceptors, while the proposed CAH assessment approach emphasizes quantifying parent and daughter compound fluxes. A paradigm for assessing SZNA at CAH sites is presented and its use is illustrated, for example former dry cleaner site, where the SZNA rate was approximately 3.5 kg/year as tetrachloroethylene (PCE) with about 80% of the mass loss attributed to groundwater flow and 20% attributed to vapor transport.","PeriodicalId":158105,"journal":{"name":"Groundwater Monitoring & Remediation","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120079238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of a Dual‐Pump Crude‐Oil Recovery System, Bemidji, Minnesota, USA","authors":"G. Delin, W. N. Herkelrath","doi":"10.1111/gwmr.12040","DOIUrl":"https://doi.org/10.1111/gwmr.12040","url":null,"abstract":"A crude‐oil spill occurred in 1979 when a pipeline burst near Bemidji, MN. In 1998, the pipeline company installed a dual‐pump recovery system designed to remove crude oil remaining in the subsurface at the site. The remediation from 1999 to 2003 resulted in removal of about 115,000 L of crude oil, representing between 36% and 41% of the volume of oil (280,000 to 316,000 L) estimated to be present in 1998. Effects of the 1999 to 2003 remediation on the dissolved plume were evaluated using measurements of oil thicknesses in wells plus measurements of dissolved oxygen in groundwater. Although the recovery system decreased oil thicknesses in the immediate vicinity of the remediation wells, average oil thicknesses measured in wells were largely unaffected. Dissolved‐oxygen measurements indicate that a secondary plume was caused by disposal of the pumped water in an upgradient infiltration gallery; this plume expanded rapidly immediately following the start of the remediation in 1999. The result was expansion of the anoxic zone of groundwater upgradient and beneath the existing natural attenuation plume. Oil‐phase recovery at this site was shown to be challenging, and considerable volumes of mobile and entrapped oil remain in the subsurface despite remediation efforts.","PeriodicalId":158105,"journal":{"name":"Groundwater Monitoring & Remediation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"118647586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Natural Buffering of Groundwater Contaminants Related to Development in Fractured Rock","authors":"M. Metcalf, G. Robbins","doi":"10.1111/gwmr.12033","DOIUrl":"https://doi.org/10.1111/gwmr.12033","url":null,"abstract":"In rural areas of New England groundwater from fractured crystalline and sedimentary bedrock is a critical water resource. Increasingly, studies have shown that development occurring in rural areas is resulting in the impairment of water quality in fractured rock aquifers. The objective of this study was to evaluate the spatial and temporal variations in groundwater quality associated with development and evaluate the extent to which common groundwater contaminants associated with rural development may be naturally buffered. The study entailed a compilation and synthesis of over 2500 reports on domestic water quality that spanned a 30 year period. Focus was placed on the spatial distribution and temporal variations in sodium, chloride, iron, manganese, nitrate, and nitrite. Results indicate that despite significant levels of development, the amount of contamination to the bedrock has been minimal. Of the constituents examined, only the chloride concentration exhibits a systematic increase over time, but the level of chloride remained relatively low. The flux of chloride to the bedrock from deicing appears minimal despite the significant amounts of road salt used in the study area. Sodium concentrations in the bedrock remained relatively constant and appear to be buffered by ion exchange with calcium as suggested by the increase in hardness with time. Iron and manganese were present at relatively low levels but did not show any systematic trends over time. Nitrate and nitrite concentrations were very low and found to be inversely correlated with manganese and iron concentrations. This suggests that the presence of iron and manganese contribute to denitrification. This study indicated that both geochemical and biogeochemical processes are active buffering mechanisms that help shield the bedrock from contaminants associated with development.","PeriodicalId":158105,"journal":{"name":"Groundwater Monitoring & Remediation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"118684318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reliable Monitoring of the Transition Zone Between Fresh and Saline Waters in Coastal Aquifers","authors":"Elad Levanon, Y. Yechieli, E. Shalev, Vladimir Friedman, H. Gvirtzman","doi":"10.1111/gwmr.12020","DOIUrl":"https://doi.org/10.1111/gwmr.12020","url":null,"abstract":"This study deals with the reliability of monitoring the transition zone between fresh and saline waters in coastal aquifers, considering the effect of tides in long‐perforated boreholes. Electric conductivity (EC) fluctuations in the coastal aquifer of Israel, as measured in long‐perforated borehole, were found to have the same periodicities as the sea tide, though some orders of magnitude larger than sea‐level or groundwater level fluctuations. Direct measurements in the aquifer through buried EC sensors demonstrate that EC measurements within the long‐perforated boreholes might be distorted due to vertical flow in the boreholes, whereas actual fluctuations of the transition zone within the aquifer are some orders of magnitude smaller. Considering these field data, we suggest that monitoring of the transition zone between fresh and saline water adjacent to the sea through long‐perforated boreholes is unreliable. EC fluctuations in short‐perforated boreholes (1 m perforation at the upper part of the transition zone) were somewhat larger than in the aquifer, but much smaller than those in the long‐perforated borehole. The short‐perforation diminishes the vertical flow and the distortion and therefore is more reliable for monitoring the transition zone in the shoreline vicinity.","PeriodicalId":158105,"journal":{"name":"Groundwater Monitoring & Remediation","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117931976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing the Environmental Performance of In Situ Thermal Remediation Technologies Using Life Cycle Assessment","authors":"G. Lemming, S. G. Nielsen, Klaus Weber, G. Heron, R. Baker, Jacqueline A. Falkenberg, M. Terkelsen, C. B. Jensen, P. L. Bjerg","doi":"10.1111/gwmr.12014","DOIUrl":"https://doi.org/10.1111/gwmr.12014","url":null,"abstract":"In situ thermal remediation technologies provide efficient and reliable cleanup of contaminated soil and groundwater, but at a high cost of environmental impacts and resource depletion due to the large amounts of energy and materials consumed. This study provides a detailed investigation of four in situ thermal remediation technologies (steam enhanced extraction, thermal conduction heating, electrical resistance heating, and radio frequency heating) in order to (1) compare the life‐cycle environmental impacts and resource consumption associated with each thermal technology, and (2) identify options to reduce these adverse effects. The study identifies a number of options for environmental optimization of in situ thermal remediation. In general, environmental optimization can be achieved by increasing the percentage of heating supplied in off peak electricity demand periods as this reduces the pressure on coal‐based electricity and thereby reduces the environmental impacts due to electricity production by up to 10%. Furthermore, reducing the amount of concrete in the vapor cap by using a concrete sandwich construction can potentially reduce the environmental impacts due to the vapor cap by up to 75%. Moreover, a number of technology‐specific improvements were identified, for instance by the substitution of stainless steel types in wells, heaters, and liners used in thermal conduction heating, thus reducing the nickel consumption by 45%. The combined effect of introducing all the suggested improvements is a 10 to 21% decrease in environmental impacts and an 8 to 20% decrease in resource depletion depending on the thermal remediation technology considered. The energy consumption was found to be the main contributor to most types of environmental impacts; this will, however, depend on the electricity production mix in the studied region. The combined improvement potential is therefore to a large extent controlled by the reduction/improvement of energy consumption.","PeriodicalId":158105,"journal":{"name":"Groundwater Monitoring & Remediation","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"119881879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}