Ground Water Monitoring and Remediation最新文献

{"title":"Society News","authors":"","doi":"10.1111/gwmr.12672","DOIUrl":"10.1111/gwmr.12672","url":null,"abstract":"","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"10-12"},"PeriodicalIF":1.8,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141585964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Vadose Zone Deserves More Attention","authors":"Chase Holton,&nbsp;Jens Blotevogel,&nbsp;Matt Lahvis","doi":"10.1111/gwmr.12677","DOIUrl":"10.1111/gwmr.12677","url":null,"abstract":"<p>The vadose zone, the variably saturated layer between the surface and groundwater table, plays a significant yet often overlooked role in subsurface contaminant fate and transport. Contaminants entering and exiting the subsurface must pass through this zone, but characterization methods are comparatively less developed than those applied to the saturated zone. Despite its importance, the vadose zone's complexity and transient nature present challenges to site characterization that have historically limited our ability to fully understand it.</p><p>Conventional vadose zone field investigations typically rely on well-established technologies, such as coring, seepage lysimeters, and geophysical methods like electrical conductivity and time domain reflectometry. While these methods continue to be used and refined, the rise of real-time and data-intensive tools holds significant promise in transforming vadose zone characterization, providing more detailed information than ever before.</p><p>New challenges have also emerged. The growing concern over per- and polyfluoroalkyl substances (PFAS), a diverse group of synthetic chemicals, has highlighted the need for improving our understanding of vadose zone retention processes. Some PFAS have surfactant properties and are known to interact strongly with air-water interfaces which can contribute to greater accumulation in the vadose zone. Investigating the subsurface transport behavior of these and other chemicals is critical to the development of robust characterization and remediation strategies.</p><p>Collectively, these papers underscore the important roles of the vadose zone in contaminant fate and transport, as well as the need for continued research to uncover the processes yet to be discovered in this dynamic environment.</p><p>We extend our sincere thanks to the authors, coauthors, and peer reviewers who contributed to this Special Issue. We hope it will serve as a valuable resource, inspiring further research and fostering a deeper appreciation of the vadose zone's roles in our practice. There is still much to learn about this critical, yet often overlooked, component of the subsurface environment.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"3"},"PeriodicalIF":1.8,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwmr.12677","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141567556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing Potential Bias in PFAS Concentrations in Groundwater and Surface Water Samples","authors":"Tom Wanzek,&nbsp;Hannah McIntyre,&nbsp;Elisabeth Hawley,&nbsp;Rula Deeb,&nbsp;Dorin Bogdan,&nbsp;Charles Shaefer,&nbsp;Bill DiGuiseppi,&nbsp;Amanda Struse,&nbsp;Trever Schwichtenberg,&nbsp;Jennifer Field","doi":"10.1111/gwmr.12669","DOIUrl":"10.1111/gwmr.12669","url":null,"abstract":"<p>Per- and polyfluoroalkyl substances (PFAS) encompass a large group of recalcitrant anthropogenic compounds that have been used in a variety of consumer and industrial products and processes over many decades. Drinking water standards were recently finalized for two PFAS at low nanogram per liter concentrations. Due to the widespread use of PFAS and low health-based thresholds, a literature review and laboratory and field studies were conducted to assess several potential sources of bias in PFAS concentrations. Fluoropolymers are commonly present in equipment, products, and materials used during field sampling, potentially leading to false positive results. Laboratory results confirmed the presence of PFAS in multiple commonly used field materials. However, best practices can be used to limit pathways for cross contamination. Laboratory-specified hold times and sample storage temperatures are scientifically founded and adequately prevent bias due to PFAS sorption to sampling containers or partial degradation of some PFAS to form others. PFAS are also known to accumulate at the air-water interface and other interfaces. Results from laboratory and field studies indicate that PFAS enrichment in foam and in the surface microlayer does occur. However, the effect of this phenomenon is within the range of analytical and spatial sampling variability and therefore a change in sampling procedures is not needed. Findings were distilled into science-based and practical recommendations to minimize bias during PFAS sampling without incurring unnecessary cost and effort.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"28-37"},"PeriodicalIF":1.8,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141567557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancing the Use of Suction Lysimeters to Inform Soil Leaching and Remediation of PFAS Source Zones","authors":"John L. Rayner,&nbsp;Amanda Lee,&nbsp;Stephen Corish,&nbsp;Simon Leake,&nbsp;Elise Bekele,&nbsp;Greg B. Davis","doi":"10.1111/gwmr.12670","DOIUrl":"https://doi.org/10.1111/gwmr.12670","url":null,"abstract":"<p>Porewater in soil vadose zones is an integrator of the fundamental processes governing the transport and partitioning of per and poly-fluoroalkyl substances (PFAS) as they move from source zones to groundwater. Suction lysimeters are being advanced as a method to provide reliable and representative PFAS porewater samples, to inform PFAS leaching and for monitoring remedial approaches. We report outcomes of lysimeter investigations across 3 sites and 18 lysimeters within fine-textured soil profiles. Soil cores were recovered from the same locations, and PFAS concentrations in soils and lysimeter porewater were compared and compared with prior laboratory investigations. Variable concentration distributions with depth of PFAS in soils were found with a maximum sum of PFAS of ~56 mg/kg dominated by perfluorooctane sulfonic acid (PFOS). The maximum sum of PFAS in porewater was 13.5 mg/L. Comparison across all collocated soil and porewater concentrations did not provide consistent trends. PFAS mass fractions within lysimeter porewater samples were much higher for most PFAS than mass fractions determined from laboratory investigations, but the fraction was lower for PFOS. The results indicate preferential recovery of individual shorter chain PFAS via leaching at lower liquid: soil ratios such as those experienced under suction during recovery of porewater by lysimeters. Suggestions are offered to advance the use of suction lysimeters in promoting porewater PFAS concentrations as an alternative for regulatory compliance, and in closing the gap between field and laboratory approaches. There is merit in using lysimeters at PFAS field sites with improvements and considerations embraced.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"49-60"},"PeriodicalIF":1.8,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwmr.12670","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141994092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting Abiotic TCE Transformation Rate Constants—A Bayesian Hierarchical Approach","authors":"Anna Störiko,&nbsp;Albert J. Valocchi,&nbsp;Charles Werth,&nbsp;Charles E. Schaefer","doi":"10.1111/gwmr.12667","DOIUrl":"https://doi.org/10.1111/gwmr.12667","url":null,"abstract":"<p>Fe(II) minerals can mediate the abiotic reduction of trichloroethylene (TCE), a widespread groundwater contaminant. If reaction rates are sufficiently fast for natural attenuation, the process holds potential for mitigating TCE pollution in groundwater. To assess the variability of abiotic TCE reduction rate constants, we collected pseudo-first-order rate constants for natural sediments and rocks from the literature, as well as intrinsic (surface-area-normalized) rate constants of individual minerals. Using a Bayesian hierarchical modeling approach, we were able to differentiate the contributions of natural variability and experimental error to the total variance. Applying the model, we also predicted rate constants at new sites, revealing a considerable uncertainty of several orders of magnitude. We investigated whether incorporating additional information about sediment composition could reduce this uncertainty. We tested two sets of predictors: reactive mineral content (measured by X-ray diffraction) combined with surface areas and intrinsic rate constants, or the extractable Fe(II) content. Knowledge of the mineral composition only marginally reduced the uncertainty of predicted rate constants. We attribute the low information gain to the inability to measure the (reactive) surface areas of individual minerals in sediments or rocks, which are subject to environmental factors like aqueous geochemistry and redox potential. In contrast, knowing the Fe(II) content reduced the uncertainty about the first-order rate constant by nearly two orders of magnitude, because the relationship between Fe(II) content and rate constants is approximately log–log-linear. We demonstrate how our approach provides estimates for the range of cleanup times for a simple example of diffusion-controlled transport in a contaminated aquitard.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 4","pages":"67-79"},"PeriodicalIF":1.8,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwmr.12667","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changepoint Analysis of Natural Attenuation in Groundwater Improves Forecasts of Time to Attain Goal","authors":"Mark L. Ferrey,&nbsp;Raymond William Bouchard Jr,&nbsp;John T. Wilson","doi":"10.1111/gwmr.12664","DOIUrl":"10.1111/gwmr.12664","url":null,"abstract":"<p>When a remedy is selected for groundwater contamination, the monitoring record is often evaluated to extract rate constants for attenuation of contaminants over time, and the rate constants are used to forecast a time when the concentrations will attain a clean-up goal. These evaluations typically assume the rate constant does not change. Data from 11 monitoring wells at the former Twin Cities Army Ammunition Plant (TCAAP) were evaluated to test whether this assumption was valid for this site. A previous evaluation at this site (based on data from 1987 through 1999) extracted rate constants that would bring the concentrations of trichloroethylene (TCE) in the 11 wells to the maximum contaminant level (MCL) on or before 2013. By 2020, only four wells had reached the MCL. Piecewise linear regressions were used to model the relationship between time elapsed and concentration of TCE for each well, and to identify any changepoints in the rate of attenuation over time. Each well had at least one changepoint with different TCE attenuation rates on either side of the changepoints. The slope of the most recent segment after the last changepoint provides the best information to forecast concentrations in the future. For four of the wells, that forecast indicated that concentrations of TCE would never reach the MCL. Piecewise linear regression analysis proved to be a valuable tool to detect changes in rate constants, and to update forecasts of the time required for groundwater concentrations to reach a cleanup goal.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 4","pages":"28-37"},"PeriodicalIF":1.8,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141355371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Representativeness of Subslab Soil Gas Collection as Effected by Probe Construction and Sampling Methods","authors":"John H. Zimmerman,&nbsp;Alan Williams,&nbsp;Brian Schumacher,&nbsp;Chris Lutes,&nbsp;Laurent Levy,&nbsp;Gwen Buckley,&nbsp;Victoria Boyd,&nbsp;Chase Holton,&nbsp;Todd McAlary,&nbsp;Robert Truesdale","doi":"10.1111/gwmr.12663","DOIUrl":"10.1111/gwmr.12663","url":null,"abstract":"<p>Subslab soil gas (SSSG) samples were collected as part of an investigation to evaluate vapor intrusion (VI) into a building. The June 2015 Office of Solid Waste and Emergency Response (OSWER) VI Guide (U.S. Environmental Protection Agency [U.S. EPA] 2015) does not provide specific, detailed recommendations regarding how to collect SSSG samples. The data collected in this study will be used to provide input into future OSWER VI Guidance documents on SSSG sample collection. To this end, three different types of subslab sampling ports were constructed with various sampling techniques within a hexagon-shaped grid in near proximity to each other. Conventional-, Vapor Pin-, and California-style ports were established in duplicate for continual analysis by onsite gas chromatography-electron capture detection (GC-ECD). Triplicate ports were established to evaluate active and passive long-term sampling methods to determine short range temporal differences. Active sampling methods included evacuated stainless-steel canisters fitted with capillary flow controllers (Modified U.S. EPA Method TO-15 [U.S. EPA 1999a]) and sorbent tubes collected using a syringe (Modified EPA TO-17 [U.S. EPA 1999b]). The Passive sampling method used was sorbent tube samples collected following the EPA TO-17 sampling method (Modified). This study did not identify any systematic differences in sample results between conventional, Vapor Pin, and CA-style probes for used in SSSG sampling. The decisions for site management would probably be the same for data from any subslab port style, active or passive sampling techniques over durations less than 2 weeks.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"106-121"},"PeriodicalIF":1.8,"publicationDate":"2024-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141370300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Data Evaluation Framework for Refining PFAS Conceptual Site Models","authors":"Jeff Gamlin,&nbsp;Charles J. Newell,&nbsp;Chase Holton,&nbsp;Poonam R. Kulkarni,&nbsp;Jonathan Skaggs,&nbsp;David T. Adamson,&nbsp;Jens Blotevogel,&nbsp;Christopher P. Higgins","doi":"10.1111/gwmr.12666","DOIUrl":"10.1111/gwmr.12666","url":null,"abstract":"<p>Contaminated sites with per- and polyfluoroalkyl substances (PFASs) are the cause of environmental, health, and financial concerns. Understanding and addressing PFASs at their source areas is important for effective characterization, risk assessment, and remediation. This paper introduces a framework that relies on commonly available PFAS data to assist in identifying PFAS source areas and assess PFAS fate and transport considerations along flowpaths. Currently accepted PFAS physical and chemical behaviors have been incorporated into metrics that can be evaluated geospatially, and/or over time, to build a weight-of-evidence approach to refine conceptual site models (CSMs). Graphical representation of data according to a PFAS “family tree” is also proposed for more consistent interpretation and pattern recognition. Combined, these tools create a PFAS data evaluation framework (PFAS Framework) that consists of a tiered analysis approach based on data availability and site complexity. Case studies from real sites are presented to demonstrate the capabilities of the PFAS Framework in identifying source areas.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 4","pages":"53-66"},"PeriodicalIF":1.8,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwmr.12666","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141271928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling and Evaluation of PFOS Retention in the Unsaturated Zone above the Water Table","authors":"Hiroko M. Hort,&nbsp;Emily B. Stockwell,&nbsp;Charles J. Newell,&nbsp;Joseph Scalia IV,&nbsp;Sorab Panday","doi":"10.1111/gwmr.12662","DOIUrl":"10.1111/gwmr.12662","url":null,"abstract":"<p>Understanding the retention of per- and polyfluoroalkyl substances (PFAS) in the vadose zone is vital to the management of impacted sites. This paper examines PFAS retention in the unsaturated zone above the water table using a mathematical model, MODFLOW-USG-Transport PFAS or “USGT-PFAS.” The USGT-PFAS model incorporates adsorption onto air-water interfaces, providing a more comprehensive understanding of PFAS retention near the water table and release to groundwater. Modeling of a hypothetical perfluorooctane sulfonic acid (PFOS) site under various idealized site conditions illustrated that the impacts on PFOS retention from smallest to largest were water table fluctuations, low episodic recharge, constant recharge, moderate episodic recharge, constant recharge with water table fluctuations, and high episodic recharge. PFOS retention also varied by sand type, with greater retention occurring in simulations incorporating coarse sand with low capillary potential versus fine sand with high capillary potential. PFAS management strategies were also explored, including the adaptation of gas sparging, a method traditionally used for volatile organic compounds. Gas sparging can concentrate PFAS in groundwater and the vadose zone around the water table, facilitating retention or removal. Model simulations for a simplified hypothetical site demonstrated that PFAS can be substantially retained in the unsaturated zone once gas sparging results in an upward concentration of PFAS in groundwater and the unsaturated zone near the water table. Modeling can aid in understanding PFAS behavior but requires simulation of multiple interrelated processes to correctly predict PFAS fate and transport in subsurface conditions.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"38-48"},"PeriodicalIF":1.8,"publicationDate":"2024-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141191949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Featured Products","authors":"","doi":"10.1111/gwmr.12652","DOIUrl":"https://doi.org/10.1111/gwmr.12652","url":null,"abstract":"","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 2","pages":"132-133"},"PeriodicalIF":1.9,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140949278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}