Download or read book Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils Scholar s Choice Edition written by U S Environmental Protection Agency and published by . This book was released on 2015-02-16 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Download or read book Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils written by United States. Environmental Protection Agency. Office of Solid Waste and Emergency Response and published by . This book was released on 2004 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Vapor Intrusion Pathway Assessment Through Long term Monitoring Studies written by Chase Weston Holton and published by . This book was released on 2015 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vapor intrusion (VI) pathway assessment often involves the collection and analysis of groundwater, soil gas, and indoor air data. There is temporal variability in these data, but little is understood about the characteristics of that variability and how it influences pathway assessment decision-making. This research included the first-ever collection of a long-term high-frequency indoor air data set at a house with VI impacts overlying a dilute chlorinated solvent groundwater plume. It also included periodic synoptic snapshots of groundwater and soil gas data and high-frequency monitoring of building conditions and environmental factors. Indoor air trichloroethylene (TCE) concentrations varied over three orders-of-magnitude under natural conditions, with the highest daily VI activity during fall, winter, and spring months. These data were used to simulate outcomes from common sampling strategies, with the result being that there was a high probability (up to 100%) of false-negative decisions and poor characterization of long-term exposure. Temporal and spatial variability in subsurface data were shown to increase as the sampling point moves from source depth to ground surface, with variability of an order-of-magnitude or more for sub-slab soil gas. It was observed that indoor vapor sources can cause subsurface vapor clouds and that it can take days to weeks for soil gas plumes created by indoor sources to dissipate following indoor source removal. A long-term controlled pressure method (CPM) test was conducted to assess its utility as an alternate approach for VI pathway assessment. Indoor air concentrations were similar to maximum concentrations under natural conditions (9.3 [micro]g/m3 average vs. 13 [micro]g/m3 for 24 h TCE data) with little temporal variability. A key outcome was that there were no occurrences of false-negative results. Results suggest that CPM tests can produce worst-case exposure conditions at any time of the year. The results of these studies highlight the limitations of current VI pathway assessment approaches and demonstrate the need for robust alternate diagnostic tools, such as CPM, that lead to greater confidence in data interpretation and decision-making.
Download or read book Vapor Intrusion Simulations and Risk Assessments written by Yijun Yao and published by Springer Nature. This book was released on 2022-07-25 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces key concepts in modeling and risk assessments of vapor intrusion, a process by which the subsurface volatile contaminants migrate into the building of concern. Soil vapor intrusion is the major exposure pathway for building occupants to chemicals from the subsurface, and its risk assessments determine the criteria of volatile contaminants in soil/groundwater in brownfield redevelopment. The chapters feature the recent advances in vapor intrusion studies and practices, including analytical and numerical modeling of vapor intrusion, statistical findings of United States Environmental Protection Agency’s Vapor Intrusion Database and Petroleum Vapor Intrusion Databases, the challenges of preferential pathways, and the application of building pressure cycling methods, and field practices of vapor intrusion risk assessments at developed contaminated sites and in brownfield redevelopment. This volume also summarizes the advantages and limits of current applications in vapor intrusion risk assessment, laying the groundwork for future research of better understanding in risk characterization of soil vapor intrusion using models. Written by experts in this field, Vapor Intrusion Simulations and Risk Assessments will serve as an invaluable reference for researchers, regulators, and practitioners, who are interested in perceiving the basic knowledge and current advances in risk assessments of soil vapor intrusion.
Download or read book Final Report written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Final Report written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Proposed Guidance for Addressing Vapor Intrusion as a Component of Superfund s Hazard Ranking System written by Jeff Polubinski and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: For decades, scientists have propounded on the risks of vapor intrusion, the process by which contaminants present in soil and groundwater migrate, via volatilization, into buildings and affect indoor air quality. After years of deliberation, the United States Environmental Protection Agency (USEPA) has now added a vapor intrusion component to the Hazard Ranking System (HRS). The USEPA uses the HRS to evaluate whether a site warrants inclusion on the agency's National Priorities List (NPL) for Superfund sites. While the inclusion of vapor intrusion on the HRS is a positive, albeit overdue, development in Superfund law, how USEPA structures and implements the vapor intrusion component into the existing HRS will determine whether this new enhancement will actually prove to be protective of human health. First, this note will examine the concept of vapor intrusion. Included in this discussion will be a description of the contaminants at play, how vapors enter buildings, where vapor intrusion sites are located, what the human health risks are and, lastly what is done to mitigate the risks that vapor intrusion presents. The note will then discuss the importance that vapor intrusion plays in the Brownfields, Superfund and the LEED-certified building discussion and why vapor intrusion is often identified as an environmental justice issue. Next, the note will discuss many of the difficulties facing vapor intrusion regulation and the roadblocks that may have inhibited the promulgation of federal regulation earlier. I will then describe the different ways states have regulated vapor intrusion by assessing two enforcement mechanisms used by states in regulating sites where vapor intrusion may be an issue. First, I will evaluate how states initially assess vapor intrusion versus how states assess other more regulated exposure pathways (such as ingestion of contaminated drinking water). If there is some sort of ranking or prioritization of sites, what weight, if any, is given to sites where vapor intrusion is an issue? Secondly, I will look at what steps states take, or require potentially responsible parties or responsible parties to take, when vapor intrusion has been identified. Lastly, based on components of state regulation, I will propose a regulatory framework for addressing vapor intrusion.
Download or read book OSWER Technical Guide for Assessing and Mitigating the Vapor Intrusion Pathway from Subsurface Vapor Sources to Indoor Air written by and published by . This book was released on 2015 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of a Screening Model for the Migration of Contaminated Soil Vapor Into the Indoor Air Environment written by Matthew Daniel Jordan and published by . This book was released on 2010 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: The migration of contaminants from the subsurface into the indoor air environment, in a process described as soil vapor intrusion, is gaining attention as a potential pathway for exposure to contaminated soil and water. Indoor, outdoor and soil air samples were collected from forty homes in North Texas to investigate the attenuation of trichloroethylene (TCE) from contaminated groundwater into residential buildings. The mean and standard deviation of the soil and indoor air attenuation factors (ratio of indoor air concentration to soil vapor concentration) were 0.14 and 0.17, respectively. Five of the 40 values were greater than 0.1 which is the suggested upper-bound by the U.S. EPA (2002). Statistical tools were used to draw correlative relationships between contaminant groundwater, soil air and indoor air concentrations. The VolaSoil model described by Waitz et al. (1996), was modified for use as a screening tool for future investigations of indoor TCE concentration. Using measured soil vapor data, the model under predicted indoor air TCE concentrations likely due to heterogeneities in the unsaturated subsurface. Inputting groundwater TCE concentrations, the model was able to capture the contaminant migration processes and produce results consistent with measured indoor TCE concentrations. Therefore, the model described in this paper maybe appropriate to be use as a screening tool in future investigations in the contamination area.
Download or read book Accuracy of Three Screening level Vapor Intrusion Models for Indoor Air written by and published by . This book was released on 2016 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vapor intrusion models were developed to predict indoor air concentrations from subsurface sources and then calculate an associated risk using toxicological data and exposure scenarios for the building occupants. Prior to the issuance of final guidance documents in 2015, the United States Environmental Protection Agency (USEPA) guidance on vapor intrusion was in draft form since November 2002. This delay between the draft version and the final guidelines resulted in the utilization of varying methodologies for assessing vapor intrusion by the regulated community and as well as the regulators at both state and local levels. The purpose of this study was to evaluate the accuracy of screening-level vapor intrusion models, using soil vapor samples collected from three sites with known or suspected contamination, and to compare the predicted indoor air results with measured indoor air results. The models evaluated were the County of San Diego Department of Environmental Health Vapor Risk 2000 Model, the Department of Toxic Substances Control (DTSC) version of the Johnson and Ettinger Model (J&E Model), and the USEPA, Office of Solid Waste and Emergency Response (OSWER), Vapor Intrusion Screening Level Calculator (VISLC). The results of this study found that the Vapor Risk 2000 Model more accurately predicts indoor air concentrations, followed by the J&E Model and VISLC. While the Vapor Risk 2000 Model more closely predicts the indoor air concentration, it does have a tendency to underpredict. Due to the underpredictions, there is more potential for false negatives (i.e., screening out sites that do have a potential for vapor intrusion. Similar to previous studies, this study found the Vapor Risk 2000 and J&E Models both over and under predict the indoor air concentrations. This may not necessarily be a reflection on the model’s prediction ability, but rather the complexity of vapor intrusion and the confounders of indoor air. Combined with additional lines of evidence (e.g., indoor air sampling), these screening-level vapor intrusion models can assist decision makers in screening in or out sites that are susceptible to vapor intrusion.
Download or read book Subsurface Vapor Intrusion to Indoor Air written by Groundwater Resources Association of California and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Guidance for Evaluating Soil Vapor Intrusion in the State of New York written by New York (State). Center for Environmental Health and published by . This book was released on 2005 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Guidance for the Evaluation and Mitigation of Subsurface Vapor Intrusion to Indoor Air written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vapor Intrusion Pathway written by Interstate Technology and Regulatory Council. Vapor Intrusion Team and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vapor Intrusion at a Site with an Alternative Pathway and a Fluctuating Groundwater Table written by Yuanming Guo and published by . This book was released on 2015 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vapor intrusion (VI), can pose health risks to building occupants. Assessment and mitigation at VI impacted sites have been guided by a site conceptual model (SCM) in which vapors originate from subsurface sources, diffuse through soil matrix and enter into a building by gas flow across foundation cracks. Alternative VI pathways and groundwater table fluctuations are not often considered. Alternative VI pathways, involving vapor transport along sewer lines and other subsurface infrastructure, have recently been found to be significant contributors to VI impacts at some sites. This study evaluated approaches for identifying and characterizing the significance of alternative VI pathways and assessed the effectiveness of conventional mitigation at a site with an alternative VI pathway that can be manipulated to be on or off. The alternative pathway could not be identified using conventional pathway assessment procedures and can only be discovered under controlled pressure method (CPM) conditions. Measured emission rates were two orders of magnitude greater than screening model estimates and sub-foundation vertical soil gas profiles changed and were no longer consistent with the conventional VI conceptual model when the CPM test was conducted. The pipe flow VI pathway reduced the vacuum performance of the sub-slab depressurization (SSD) VI mitigation system, but the SSD system still provided sufficient protection to the house. The relationship between groundwater table fluctuations and subsurface vapor emissions and transport is examined using multi-year data from the field site, and is studied in the laboratory. In addition, a broader range of conditions is examined through use of modeling validated with the experimental data. The results indicate that fluctuating groundwater tables will lead to amplified volatile organic chemical (VOC) emissions from groundwater to soil surface relative to steady water table elevation, however, the magnitude of this amplification is less concerned when long-term water fluctuation present. No clear correlations were found between VOC emissions and water table changes at the study site where annual water table fluctuations of about 0.3 m existed. Significant VOC emission amplifications by water table fluctuation would be expected under shallow groundwater conditions according to model analysis results.
Download or read book Guidance for Evaluating Soil Vapor Intrusion in Washington State written by Washington (State). Department of Ecology and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lack of Final Guidance on Vapor Intrusion Impedes Efforts to Address Indoor Air Risks written by CreateSpace Independent Publishing Platform and published by Createspace Independent Publishing Platform. This book was released on 2018-07-16 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lack of final guidance on vapor intrusion impedes efforts to address indoor air risks
