Ground Water Monitoring and Remediation最新文献

{"title":"A New Look at Diffusion in Vapor Intrusion Assessments; Passive Adsorptive Diffusion Samplers","authors":"Michael Niemet,&nbsp;Ben Thompson,&nbsp;Katie Rabe,&nbsp;Harry O'Neill","doi":"10.1111/gwmr.12683","DOIUrl":"https://doi.org/10.1111/gwmr.12683","url":null,"abstract":"<p>Vapor intrusion of toxic volatile organic compounds (VOCs) from subsurface soil vapor, through a building slab/floor, and into the indoor air is an important environmental contaminant transport mechanism. It is widely believed that advective flow, driven by the pressure differential between the subslab and indoor air, is the primary mechanism of subslab soil vapor entry into buildings. This paper explores the hypothesis that molecular diffusion through the slab may potentially play a larger role in vapor intrusion than previously believed and may even be the predominant vapor intrusion mechanism when the subslab vapor source strength is sufficiently high or the pressure differential is relatively low. A novel sampling device, referred to as a Passive Adsorptive Diffusion Sampler (PADS), is presented for the purpose of directly measuring the diffusion of VOCs through a building slab. A vacant warehouse was identified as a case study site where historical sampling had determined that vapor intrusion of trichloroethene (TCE) was adversely impacting the indoor air. Calculations using Fick's First Law of Diffusion are presented which demonstrate that diffusion alone can theoretically account for all the TCE observed in the indoor air at this building based on an effective diffusion coefficient for concrete that was calculated from the Johnson and Ettinger Model. Two groups of nine replicate PADS were deployed at two areas on the slab and used to measure the flux and effective diffusion coefficient at each of the 18 total points, which showed an order of magnitude variability within each area and over two orders of magnitude variability overall. These results indicate that diffusion through concrete is inherently variable when measured at a sub-meter scale. However, when combined over both areas, the overall average approached that calculated from the Johnson and Ettinger Model. An additional 12 PADS were deployed across the building slab (for a total of 30) to quantify the overall building-wide diffusive flux. This area-weighted average diffusive flux was consistent with the predicted diffusive flux as calculated from Fick's First Law and the vapor intrusion mass input required to achieve the observed indoor air TCE concentration. The results of this study show that PADS provides a simple way to measure diffusive flux directly without having to drill through the slab. However, significant variability in the measured flux should be expected and will need to be accounted for by the inclusion of a relatively large number of samples including replicates. When using PADs at a new site, the collection of traditional subslab vapors at a select number of locations is recommended for the verification of a building-specific effective diffusion coefficient, which may not necessarily be the same as for this building.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"45 1","pages":"30-54"},"PeriodicalIF":1.8,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431628","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":"Studies in Parameter Estimation for Analytical Transport Equations","authors":"Andrew Mills","doi":"10.1111/gwmr.12684","DOIUrl":"10.1111/gwmr.12684","url":null,"abstract":"<p>Three new programs have been developed to perform parameter estimation to assist in the calibration of analytical contaminant transport models. The Domenico equation was chosen as an example analytical model for each of the three programs rather than a model with the exact solution, because the former is a closed-form expression involving significantly less processing time. One of the programs studied is a quasi-exhaustive search method and the second is a successive parameter variation method. The third program is based on Box's Complex nonlinear, direct-search optimization method. The three programs and an already available calibration tool (PEST) were compared in tests using data from two different sites in southeastern Pennsylvania. These tests demonstrated the validity of the three programs as examples to assist the calibration of groundwater analytical transport models. The final estimates for the parameter values for the three methods and PEST applied to the data from each of the two sites compared quite closely and, with two exceptions were well within an order of magnitude of each other. The three newly available programs individually should serve as calibrating tools indispensable for field hydrogeologists, environmental project managers, and others who have been asked to run analytical transport models. The results from the runs performed on the two sites indicate the Complex method to be the best option as a calibration tool, with the quasi-exhaustive method and the successive parameter estimation method being acceptable alternatives.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"45 1","pages":"80-87"},"PeriodicalIF":1.8,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195399","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":"Issue Information - ISSN page","authors":"","doi":"10.1111/gwmr.12528","DOIUrl":"https://doi.org/10.1111/gwmr.12528","url":null,"abstract":"","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"2"},"PeriodicalIF":1.8,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwmr.12528","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141994187","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":"Featured Products","authors":"","doi":"10.1111/gwmr.12675","DOIUrl":"https://doi.org/10.1111/gwmr.12675","url":null,"abstract":"","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"146-147"},"PeriodicalIF":1.8,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141994195","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":"Climatic Effects on Vapor Flow and Behavior in the Vadose Zone","authors":"Bart Eklund","doi":"10.1111/gwmr.12682","DOIUrl":"10.1111/gwmr.12682","url":null,"abstract":"<p>The concentrations and transport of volatile organic compounds (VOCs) and other vapors in the vadose zone may exhibit some degree of temporal variability due to the effect of various climatic factors, including (1) Air temperature; (2) Barometric pressure; (3) Surface winds; and (4) Soil moisture, including the effects of any water infiltration and/or changes in groundwater level. These variables may directly affect the rates of gas transport through the vadose zone or may indirectly affect transport by changing the soil-gas concentrations at a given location and depth. To understand the potential effect of these factors due to climate change, it is first necessary to understand their effect over typical time periods of one to several days, seasonally, and annually. In this paper, the effects of the above variables over various time periods are presented and the long-term effects due to climate change are discussed. Standard approaches for soil-gas measurement attempt to account for these variables, either to negate their potential influence or to capture data under reasonably worst-case conditions. The appropriateness and adequacy of typical soil vapor measurement approaches are discussed.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 4","pages":"80-91"},"PeriodicalIF":1.8,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwmr.12682","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142195400","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":"Complementary Field and Laboratory Batch Studies to Quantify Generation Rates of Perfluoroalkyl Acids in a Contaminated Agricultural Topsoil with Unknown Precursors","authors":"Alexander Arthur Haluska,&nbsp;Klaus Röhler,&nbsp;Joel Fabregat-Palau,&nbsp;Diogo A. M. Alexandrino,&nbsp;Sergey Abramov,&nbsp;Katharine J. Thompson,&nbsp;Daniel Straub,&nbsp;Sara Kleindienst,&nbsp;Boris Bugsel,&nbsp;Jonathan Zweigle,&nbsp;Christian Zwiener,&nbsp;Peter Grathwohl","doi":"10.1111/gwmr.12680","DOIUrl":"https://doi.org/10.1111/gwmr.12680","url":null,"abstract":"<p>Soil microbiome changes and generation rates of per- and polyfluoroalkyl substances (PFAS) precursors were studied in a contaminated agricultural field using a combination of field and laboratory batch microcosm studies. 16S rRNA gene amplicon sequencing was used to track how microbial community composition changed over time, while perfluoroalkyl acids (PFAA) generation rates were quantified using a combination of field and batch incubations combined with the direct total oxidizable precursor (dTOP) assay. The study site in Brilon-Scharfenberg, North Rhine-Westphalia, Germany, has PFAS contamination in the topsoil (0 to 30 cm) originating from compost. Generation rate constants of these short-chain PFAA estimated from batch incubations (0.12 to 0.75 1/year) were higher but similar to rate constants from the fields (0.05 to 0.22 1/year). Long-term field mass discharge data (2009 to 2023) suggest that at least 60 years are needed to remove 99.99% of short-chain PFAA and their precursors. 16S rRNA gene amplicon sequencing data revealed a major impact of PFAA on the biodiversity of soil microorganisms, with batch-incubated contaminated soils showing higher richness and diversity indexes than field control soils. However, most of these impacts occurred at lower taxonomical ranks and did not seem to have a prominent impact on the overall structure of the autochtonous microbial communities of the soils where PFAA were produced and accumulated. Overall, our findings demonstrate that well-controlled aerobic batch test combined with the results of dTOP assay are a suitable approach for estimating short-chain PFAA generation rates. Additionally, our research suggests that the complete removal of PFAA precursors from topsoil will take decades.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"61-75"},"PeriodicalIF":1.8,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwmr.12680","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141994194","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":"Highlight","authors":"Mike Price","doi":"10.1111/gwmr.12678","DOIUrl":"10.1111/gwmr.12678","url":null,"abstract":"","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"144-145"},"PeriodicalIF":1.8,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780993","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":"High-Resolution Forensic Evaluation of Nitrate-Contaminated Groundwater","authors":"Michael Sklash,&nbsp;Fatemeh Vakili","doi":"10.1111/gwmr.12681","DOIUrl":"10.1111/gwmr.12681","url":null,"abstract":"<p>Determining the source(s) of nitrate contamination in agricultural areas is complicated; doing this as a forensic evaluation for litigation in one field week is especially challenging. The objective of this 2021 investigation, conducted for an agricultural producer who began applying animal waste in 2007, was to determine whether animal waste was the source of nitrate reported at downgradient residential wells. The test Site was a 180 acre, irrigated field that overlies a thick sand aquifer with the water table at about 20 ft below ground level (fbgl). We used multiple lines of evidence to resolve the source(s) of nitrate at three test locations at the Site using continuous vertical testing for hydraulic conductivity and high-resolution vertical testing of selected chemical and isotopic parameters in water at 5-ft depth intervals between 5 and 80 fbgl. We found that beneath the Site at the depth interval of most of the impacted residential wells: (1) groundwater travel time indicates nitrate at the impacted residential wells could not have originated from the Site, (2) the groundwater age based on tritium (³H) pre-dates the establishment of manure spreading, and (3) the nitrogen-15 concentrations (δ¹⁵N) in nitrate indicate the nitrate is not all, if in any part, due to animal waste. This high-resolution investigation clearly indicated that the agricultural producer was not responsible for the impacted residential wells and was completed in only 1 week.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"128-143"},"PeriodicalIF":1.8,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141780994","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":"Safe Drinking Water Act 50th Anniversary—Recognizing an Evolving Path of Groundwater Management and Protection","authors":"Charles Job","doi":"10.1111/gwmr.12671","DOIUrl":"10.1111/gwmr.12671","url":null,"abstract":"","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 3","pages":"22-27"},"PeriodicalIF":1.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141745275","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":"Identification of Aerobic ETBE-Degrading Microorganisms in Groundwater Using Stable Isotope Probing","authors":"Henry C.G. Nicholls,&nbsp;H. Emma Mallinson,&nbsp;Steven F. Thornton,&nbsp;Markus Hjort,&nbsp;Stephen A. Rolfe","doi":"10.1111/gwmr.12679","DOIUrl":"10.1111/gwmr.12679","url":null,"abstract":"<p>A limited number of microorganisms have been identified with the capability to degrade ethyl <i>tert</i>-butyl ether (ETBE) in the environment. Knowledge of the identity and distribution of ETBE-degrading microorganisms is important for the implementation of management measures such as natural attenuation and bioremediation at ETBE-release sites. In this study, DNA-stable isotope probing (SIP) was used to identify microorganisms able to aerobically degrade ¹³C-labeled ETBE in laboratory microcosms constructed with groundwater and aquifer material from an ETBE-release site. Microorganisms in the Class γ-proteobacteria, Order β-proteobacteriales, Family Burkholderiaceae, and classified as <i>Methylibium</i> and <i>Leptothrix</i>, respectively, were identified as primary ETBE degraders. Comparisons with ETBE-responsive microorganisms (those which increased in abundance after the addition of ETBE), identified by high-throughput sequencing of microcosms established from the same site, showed that only a small proportion of the ETBE-responsive organisms were primary degraders as determined by SIP. ETBE degraders were taxonomically related to microorganisms able to degrade other gasoline components, but not ETBE, implying that this functionality results from acquisition of the <i>eth</i> gene cluster by these organisms. These ETBE degraders could also be identified at ETBE-release sites, but at low relative abundance and generally only in those locations from which the microcosms had been established. Therefore, we recommend that molecular investigations of ETBE-contaminated sites focus on functional genes (i.e., the <i>eth</i> gene cluster) rather than specific taxa.</p>","PeriodicalId":55081,"journal":{"name":"Ground Water Monitoring and Remediation","volume":"44 4","pages":"92-103"},"PeriodicalIF":1.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/gwmr.12679","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141745284","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}