National Risk Management Research Laboratory Research Articles

Environmental Protection for Sustainability

It is amazing how all the events and activities in our lives are interconnected. As a young boy growing up in El Paso, Texas, I was exposed to many aspects of life and even had family relatives from all social classes. This never bothered me, because they were family and it made me aware there was a huge and vastly different world beyond the street that I lived on. While I could see the apparent differences between these social classes, it never really occurred to me there were also differences that occurred under the surface of what was seen. You are probably wondering why I am beginning this editorial with this, but as you read, you will see that these experiences and events in my life have shaped me as a man, a son, and a father. These experiences have also contributed to my approach as a researcher at the U.S. Environmental Protection Agency (EPA) and the reason why I wanted to share the research in this special feature issue with you. Growing up in a city on the United States border with Mexico really opened up my eyes to the stark differences between the two countries. Not only in the style of living and the culture, but also in daily things we take for granted. Such as the air we breathe, the water we drink and play in, and to the land we live on. Of course, these are issues that affect any city, but in my opinion, they are heightened when it occurs in a metropolis that spans two countries and one border. Additionally, the two cities are tied at the hip, since they are geographically close, in this case separated by the Rio Grande, and any environmental event that occurs in one city is more than likely felt in the other. I can remember driving to school at the University of Texas—El Paso every morning and seeing a thick yellow layer of smog and pollution that blanketed Juarez, Mexico and extended into a portion of El Paso. I can also remember the dirt streets in the Colonias in Juarez, Mexico with tremendous amounts of trash and the erosion from the runoff from the rains (when we did get rain), to the lack of water in both cities and being told by the City of El Paso what days we could use water outside. This was an initial effort the city was making in hopes of extending the available water resources within the region. These memories of El Paso, as well as many others, are so fresh in my memory, even to this day, I can still remember so vividly one activity I did with my grandparents every other weekend that really put into context the concept of environmental protection, even though I did not know it was doing so at the time. We had family that lived in a Colonia in Juarez, Mexico; my uncle, John, his wife Patty, and their son, Pepe, my cousin. While John was a U.S. citizen, he chose to live in Mexico with his wife and their extended family. He did this, because it made him happy. I remember going to their house for the first time when I was about 9 years old. When I first saw where they lived, I was really surprised not from what I saw, but the fact that it was not the same as our house. Their house had cement and dirt floors, electricity was provided from a generator, and from what I remember their city services were very limited (water and sewer). I remember their street was not paved and garbage was strewn everywhere throughout the neighborhood. But, it was my Uncle’s home and he loved it. I too loved going there to visit my family and spend time with my cousin. But, the fact that they lived in so drastically different conditions made me realize that not everyone lived at the same standard of living as we did in the States. To help them out, my paternal grandparents M. A. Gonzalez (&) United States Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory, Cincinnati, OH, USA e-mail: gonzalez.michael@epa.gov

A technologist visits sustainability

There was a time, not in too distant past, when Microsoft Word would not recognize the word ‘‘sustainability’’ in a text. Since then authors from all walks of life have written numerous narratives on sustainability or sustainable development. The United Nations and most governments on the planet have come together to promote sustainable development globally and nationally. Industry, especially large multinational corporations, have created their own organizations to promote sustainability. Local governments in every corner of the world are proponents of sustainability with programs titled ‘‘sustainable this’’ or ‘‘green that’’ to implement it. A responsible citizen dutifully separates recyclables from household wastes. Another drives a hybrid or an electric car. Yet another citizen volunteers for a citizen action group to promote solar or wind power. Are these behaviors contributing to sustainability? There can be two short answers, of which the first is: Perhaps. The second answer: We really would not be able to tell without knowing what the other interacting agents in society naturally do. The economy and society are vastly more complex than the simple causal relationship that we use such as ‘‘if we do this, that happens.’’ Profound confusions remain at every level of society about what one is supposed to do about sustainability. From the point of view of the science and engineering research, here is an attempt to make some sense on how this research community might look at sustainability. The word ‘‘sustainability’’ nowadays is as frequently used to connote its common sense meaning as to reflect the sense that came from the global environmental movement, generally accepted to have been popularized by the Bruntland commission report, our common future, of the UN-sponsored world commission on environment and development (WCED). No science dictionary has a useful scientific definition of the term. This is not surprising. Even though sustainability has penetrated many fields of science and engineering, the understanding varies from person to person, discipline to discipline. In truth, this is a sociopolitical idea, not a scientific one. Prof. J. Pop-Jordanov of Macedonia has compiled the distinctive ideas that are central to different professions in this context. For instance, for an economist, quantifying the environmental ‘‘externalities’’ is central to assessing human welfare. An ecologist is focused on studying the ways the carrying and regenerative capacities of natural resources are impaired by human enterprise. To a physicist, sustainability is ‘‘the ability of biological systems to fight against degradation of energy and resources (entropy) by creating new forms of order (negentropy) using the various inputs of solar energy.’’ To a chemist or an engineer, however, it is ‘‘the challenge to complete material and energy life cycles created by human activities, through new techniques for material design, re-use, recycling and waste management.’’ Though these disciplinary foci can be highly technical, none of them captures the sociopolitical definition given by the Bruntland commission report: ‘‘Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.’’ This report is human centric, and its emphasis of intraand inter-generational equity is clear. It cried out for an unspecified plan of action to reverse widespread environmental damage to our planet by human activities, depleting finite natural resources in the process, and creating a huge gulf between ‘‘Haves’’ and ‘‘Have Nots’’. Our common future did not define sustainability per S. Sikdar (&) National Risk Management Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH, USA e-mail: sikdar.subhas@epa.gov

Resurgence of fossil fuels?

The famed Shell Geophysicist M. King Hubbert predicted in the 1950s that oil production in the United States would peak in the 1970s and decline thereafter, creating an ever increasing shortage and consequent dependence on imports to power the increasing societal needs. The facts from the U.S. oil companies quickly confirmed the predicted decline, and Peak Oil became an instantly recognizable moniker to be used in debates about U.S. oil independence and alternative energy. Because of high energy content and portability, petroleum already was a world commodity. Cheap petroleum in global commerce provided mutual benefits to both the exporting nations, many in the developing nations especially in the Middle East, and advanced nations of the West. This symbiosis was shattered in 1973 during the Yom Kippur war when oil was used as a political weapon known as the oil embargo resulting in gasoline shortage and long lines at the gas stations. During regular discourse in political, communication media, and academic circles, words like oil and energy became synonymous. Peak Oil was being confused as Peak Energy. Efforts to aggressively develop alternative sources of energy started in earnest at that time. Peak Oil was a constant inspiration to these efforts. Most of the attention at the time was focused on synthetic fuels via coal gasification and liquefaction. A huge Federal Government spending was undertaken to economically develop variations of the old German Fischer–Tropsch and Bergius processes. These efforts failed, and after the end of the oil embargo, were largely abandoned. Then in the 1990s concerns about global warming became greatly intensified with the publication of the first assessment report of the UN Intergovernmental Panel on Climate Change (IPCC), which claimed that the observed warming of the average global temperature was linked to the emission of greenhouse gases from anthropogenic sources, such as power plants, transportation vehicles, and manufacturing facilities. Follow-up reports continued to claim this linkage. The climate models used by the IPCC predicted catastrophic consequences for parts of the Earth in the near future. There is controversy about these predictions and about the adequacy of these models in reliably predicting a very complex system such as the climate. A majority of the governments of the 194-member IPCC countries supported these conclusions and wanted remedial actions through the Kyoto Protocol adopted in 1997. The results have been unsatisfactory and attempts are still underway to regain some momentum on programs on greenhouse gas emission reduction. Parallel to the Kyoto effort, another concern emanated from the UN-sponsored summit on sustainable development, held first in Rio in 1992, and revisited twice since then. Sustainable development, as the readers of this and other publications would know, is a broader concern than greenhouse effect. Environmental degradation, resource depletion, and intraand intergenerational equity drove global sustainability agenda. Global warming concerns greatly intensified these concerns. Thus the two movements merged: one to limit greenhouse gases and the other to preserve the environment for societal benefit. Peak Oil was not a major driver anymore for finding fossil alternatives to petroleum. Interestingly, Peak Oil in the sense of Peak Energy is still being invoked to support the development of nonfossil alternatives such as petroleum. The resource S. K. Sikdar (&) National Risk Management Research Laboratory, U.S Environmental Protection Agency, 26 W. M.L. King Dr., Cincinnati, OH 45268, USA e-mail: sikdar.subhas@epa.gov

Flue gas desulphurisation in Serbia: Technologies, legal and economic aspects

Combustion of coal results in sulfur dioxide (SO2) emissions which cause detrimental impacts on the environment and human health. Electric power generating units account for the majority of SO2 emissions in Serbia. Environmental regulations in Serbia require gradual implementation of flue gas treatment technologies for control the emissions of pollutants into the atmosphere. As far as Serbian thermal power plants are concerned, the basic design of systems for flue gas desulphurisation has been developed for two thermal power plants. As wet limestone-based FGD technologies dominate in the world because of high SO2 removal efficiency, cost effectiveness, and gypsum as the by-product, it is expected that Serbian thermal power plants will use this technology. This paper presents a review of commercially available FGD technologies, as well as legal and economic perspective of the process. U.S. EPA's National Risk Management Research Laboratory has published the Coal Utility Environmental Cost Workbook which provides the rough-order-of-magnitude budgetary cost estimates as the starting point for the limestone forced oxidation cost model that might be a good starting point for cost estimates for Serbian electric utilities.

Model for hydraulic networks with evenly distributed demands along pipes

This article shows how the global gradient method formulated by Todini and Pilati (Todini, E. and Pilati, S., 1987. A gradient algorithm for the analysis of pipe network. In: International conference on computer applications for water supply and distribution, Leicester Polytechnic, UK) can be modified in order to represent user water demand evenly distributed along pipes. It is also shown how EPANET (Rossman, L.A., 2000. EPANET 2 users manual, Cincinnati, Ohio, USA: National Risk Management Research Laboratory, Office of Research and Development, US Environmental Protection Agency), which assumes demands to be allocated to the nodes, can be used to represent this type of distributed demand. The proposed procedure is based on an original mathematical method formulated by Messina (Messina, U., 1945. Metodi approssimati per i calcoli di verifica delle reti di condotte idrauliche. L'Acqua, 1 (12), 1–11 (in Italian)). Two different numerical examples relating to networks of different topological complexity are discussed. In particular, it is highlighted that the two different ways of modelling demand lead to different nodal head values that are generally lower when demand is evenly distributed along the pipes. However, differences decrease when the piezometric surface is fairly flat over the network (i.e. low water velocities in the pipes). The article concludes with several considerations regarding the consequences that the method of representing demand has on the processes of calibration and optimal design/rehabilitation of water distribution networks and leakage estimation.

Role of Stream Restoration on Improving Benthic Macroinvertebrates and In-Stream Water Quality in an Urban Watershed: Case Study

Many stream restoration projects do not include a requirement for long-term monitoring after the project has been completed, resulting in a lack of information about the success or failure of certain restoration techniques. The National Risk Management Research Laboratory, part of the U.S. EPA Office of Research and Development, evaluated the effectiveness of stream bank and channel restoration as a means of improving in-stream water quality and biological habitat in Accotink Creek, Fairfax City, Va., using discrete sampling and continuous monitoring techniques before and after restoration. This project monitored the effects of a 549 m (1,800 linear-ft) restoration of degraded stream channel in the North Fork of Accotink Creek. Restoration, which was intended to restore the stream channel to a stable condition, thereby reducing stream bank erosion and sediment loads in the stream, included installation of native plant materials along the stream and bioengineering structures to stabilize the stream channel and bank. Results of sampling and monitoring for 2 years after restoration indicated a slight improvement in biological quality for macroinvertebrate indices such as Virginia Stream Condition Index, Hilsenhoff Biotic Index, and Ephemeroptera, Plecoptera, Trichoptera taxa; the differences were statistically significant at 90% level of confidence with the power of greater than 0.8. However, indices were all below the impairment level, indicating poor water quality conditions. No statistically significant differences in chemical constituents and bacteriological indicator organisms were found before and after restoration as well as upstream and downstream of the restoration. The results indicated that stream restoration alone had little effect in improving the conditions of in-stream water quality and biological habitat, though it has lessened further degradation of stream banks in critical areas where the properties were at risk. Control of storm-water flows by placing best management practices in the watershed might reduce and delay discharge to the stream and may ultimately improve habitat and water quality conditions.

Research Issues Underlying the Four-Lab Study: Integrated Disinfection By-Products Mixtures Research

Chemical disinfection of drinking water is a major public health triumph of the 20th century, resulting in significant decreases in morbidity and mortality from waterborne diseases. Disinfection by-products (DBP) are chemicals formed by the reaction of oxidizing disinfectants with inorganic and organic materials in the source water. To address potential health concerns that cannot be answered directly by toxicological research on individual DBPs or defined DBP mixtures, scientists residing within the various organizations of the U.S. Environmental Protection Agency's Office of Research and Development (the National Health and Environmental Effects Research Laboratory, the National Risk Management Research Laboratory, the National Exposure Research Laboratory, and the National Center for Environmental Assessment) engaged in joint investigation of environmentally realistic complex mixtures of DBP. Research on complex mixtures of DBP is motivated by three factors: (a) DBP exposure is ubiquitous to all segments of the population; (b) some positive epidemiologic studies are suggestive of potential developmental, reproductive, or carcinogenic health effects in humans exposed to DBP; and (c) significant amounts of the material that makes up the total organic halide portion of the DBP have not been identified. The goal of the Integrated Disinfection Byproducts Mixtures Research Project (the 4Lab Study) is provision of sound, defensible, experimental data on environmentally relevant mixtures of DBP and an improved estimation of the potential health risks associated with exposure to the mixtures of DBP formed during disinfection of drinking water. A phased research plan was developed and implemented. The present series of articles provides the results from the first series of experiments.

Application of QSARs and VFARs to the rapid risk assessment process at US EPA

With continued development of new chemicals and genetically engineered microbes as potential agents for terrorism and industrial development, there is a great need for the continued development and application of quantitative structure activity relationships (QSARs) and virulence factor activity relationships (VFARs). Development and application of QSARs and VFARs will facilitate efficient and streamlined use of dwindling resources and assessment of risks associated with exposures to chemical and biological agents. To facilitate the continued development of QSARs and VFARs at US Environmental Protection Agency, a two day workshop was organized June 20–21, 2006, in Cincinnati, OH, USA. This article summarizes the workshop report by highlighting the importance of continued QSAR research, the current state of VFAR science, and the guidance provided to the National Homeland Security Research Center and National Risk Management Research Laboratory by an expert panel for the continued use and development of computational approaches.

Sustainability Perspective and Chemistry-Based Technologies

ADVERTISEMENT RETURN TO ISSUECommentaryNEXTSustainability Perspective and Chemistry-Based TechnologiesSubhas K. SikdarView Author Information National Risk Management Research Laboratory, United States Environmental Protection Agency, Cincinnati, Ohio 45268Cite this: Ind. Eng. Chem. Res. 2007, 46, 14, 4727–4733Publication Date (Web):June 1, 2007Publication History Published online1 June 2007Published inissue 1 July 2007https://doi.org/10.1021/ie0700056Copyright © 2007 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views369Altmetric-Citations20LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (188 KB) Get e-AlertsSUBJECTS:Energy,Fossil fuels,Materials,Sustainability,Wastes Get e-Alerts

Application of the US decision support tool for materials and waste management

The US Environmental Protection Agency (US EPA) launched the Resource Conservation Challenge (RCC) in 2002 to help reduce waste and move towards more sustainable resource consumption. The objective of the RCC is to help communities, industries, and the public think in terms of materials management rather than waste disposal. Reducing cost, finding more efficient and effective strategies to manage municipal waste, and thinking in terms of materials management requires a holistic approach that considers life-cycle environmental tradeoffs. The US EPA’s National Risk Management Research Laboratory has led the development of a municipal solid waste decision support tool (MSW-DST). The computer software can be used to calculate life-cycle environmental tradeoffs and full costs of different waste management or materials recovery programs. The environmental methodology is based on the use of life-cycle assessment and the cost methodology is based on the use of full-cost accounting. Life-cycle inventory (LCI) environmental impacts and costs are calculated from the point of collection, handling, transport, treatment, and disposal. For any materials that are recovered for recycling, offsets are calculated to reflect potential emissions savings from use of virgin materials. The use of the MSW-DST provides a standardized format and consistent basis to compare alternatives. This paper provides an illustration of how the MSW-DST can be used by evaluating ten management strategies for a hypothetical medium-sized community to compare the life-cycle environmental and cost tradeoffs. The LCI results from the MSW-DST are then used as inputs into another US EPA tool, the Tool for the reduction and assessment of chemical and other environmental impacts, to convert the LCI results into impact indicators. The goal of this paper is to demonstrate how the MSW-DST can be used to identify and balance multiple criteria (costs and environmental impacts) when evaluating options for materials and waste management. This type of approach is needed in identifying strategies that lead to reduced waste and more sustainable resource consumption. This helps to meet the goals established in the US EPA’s Resource Conservation Challenge.

English

Over the past 15 years, MSE Technology Applications has conducted several notable technology demonstrations of biologically based technologies to treat acid rock drainage (ARD). These projects have progressively evolved under the U.S. Environmental Protection Agency’s Mine Waste Technology Program (MWTP) and have resulted in significant advances in the development of bioreactor application of sulfate-reducing bacteria (SRB) technology. In this paper, summary information from four separate demonstration projects will be presented for the purpose of providing overviews of the bioreactor design parameters and the operation and development of each bioreactor system. Test methods and data analysis information for each project is not fully provided within this paper, as it is available from other sources. Summarized treatment results will be presented in this paper for three field-demonstrations. Additionally, results of one laboratory design project will be presented. A different bioreactor configuration was employed for each of the four projects. The first design to be presented will be an in situ bioreactor. This configuration was installed within the flooded subsurface workings of the Lilly Orphan Boy Mine in Montana and was operated between 1994 and 2005. The second design to be presented will be a set of on-site SRB bioreactors that were configured in parallel at the Calliope Mine in Montana. These test bioreactors allowed various operational attributes to be evaluated including lime pretreatment and temperature. The configuration of the third design to be presented will be a set of both anaerobic and aerobic bioreactors in staged fashion at the Surething Mine in Montana. This bioreactor design has been in operation since 2001 and shows the comprehensive applicability for biological treatment of ARD. The focus of the last project to be presented will be an investigative approach to bioreactor design. This resulted in a proposed bioreactor configuration to effectively treat ARD by reducing dissolved sulfate and heavy metals concentrations. In general, MWTP results from these four bioreactor configurations show that SRB bioreactors are effective for passive ARD treatment. ______________________ 1 Paper presented at the 7 th International Conference on Acid Rock Drainage (ICARD), March 26-30, 2006, St. Louis MO. R.I. Barnhisel (ed.) Published by the American Society of Mining and Reclamation (ASMR), 3134 Montavesta Road, Lexington, KY 40502 2 Suzzann Nordwick, Senior Engineer; Marek Zaluski, Staff Engineer; and Brian Park, Senior Engineer, MSE Technology Applications, Inc., Mike Mansfield Advanced Technology Center, 200 Technology Way, P.O. Box 4078, Butte, Montana 59702, USA, and Diana Bless, United States Environmental Protection Agency, National Risk Management Research Laboratory, 26 West Martin Luther King Drive, Cincinnati, Ohio 45268, USA 7 th International Conference on Acid Rock Drainage, 2006 pp 1410-1420 DOI: 10.21000/JASMR06021410

A Summary of the EPA's Fuel Cell Program Dealing with the Environmental Life Cycle Assessment

This article summarizes the U.S. Environmental Protection Agency (EPA) National Risk Management Research Laboratory's Fuel Cell Program (www.epa.gov/ORD/NRMRL/std/fuelcell) and presents interim findings of an ongoing project aimed at quantifying how clean fuel cell technology is from “cradle-to-grave” compared to conventional power generation processes. Data and data sources will be reviewed by fuel cell type (polymer exchange membrane, phosphoric acid fuel cell, solid oxide fuel cell, molten carbonate fuel cell, etc.) and life cycle stage (manufacture, use, end of life). Data gaps will also be identified as well as proposed EPA strategies for filling these “knowledge” gaps regarding the environmental attributes of fuel cells.

The status of life‐cycle assessment as an environmental management tool

AbstractAs environmental awareness increases, industries and businesses have responded by providing “greener” products and using “greener” processes. Many companies have found it advantageous to explore ways of moving beyond compliance, using pollution prevention strategies and environmental management systems, to improve their environmental performance. One such way is life‐cycle assessment (LCA). This concept considers the entire life cycle of a product, process, or an activity. Evaluating environmental impacts holistically from raw material acquisition, through manufacture, use, and disposal using a life‐cycle perspective is gradually being viewed by environmental managers and decision makers as an important element in achieving environmental sustainability. The use of a holistic, life‐cycle approach can help industry and government avoid the unintended trading of one environmental problem for another. This paper addresses ongoing research in LCA methodology in the US EPA's National Risk Management Research Laboratory. Two key areas of this research include life‐cycle inventory (LCI) data availability and life‐cycle impact assessment (LCIA) modeling.To address the issue of data availability, EPA developed a website entitled LCAccess. Although LCAccess does not itself contain data, it is a searchable global directory to potential data sources. LCAccess also serves as a central source for LCA information. In addition, EPA developed TRACI (the Tool for the Reduction and Assessment of Chemical and other environmental Impacts), which allows the characterization of ozone depletion, global warming, acidification, eutrophication, tropospheric ozone (smog) formation, ecotoxicity, human particulate effects, human health, fossil fuel depletion, and land use effects. TRACI can be used with life‐cycle inventory to further analyze and understand the data. © 2004 American Institute of Chemical Engineers Environ Prog, 2004

Assessment and Management of Watershed Microbial Contaminants

Numerous sources of infectious disease causing microorganisms exist in watersheds and can impact recreational and drinking water quality. Organisms of concern include bacteria, viruses, and parasites. The watershed manager is challenged to limit human contact with pathogens, limit the numbers of pathogens reaching surface or groundwaters, and limit the pathogens reaching crops eaten raw to levels below those needed to cause infection. Therefore, the goal of the National Risk Management Research Laboratory's (NRMRL) watershed pathogens research program is to develop optimum solutions for managing the complex problem of watershed microbial contamination and thus support watershed managers' decision making. It supports the Agency's Strategy for Waterborne Microbial Disease Control by addressing contamination sources, named in the strategy as one of the highest priority approaches to water protection. This paper summarizes the current state of the knowledge on the sources and impacts of microbial pathogens in the watershed and discusses challenges to their successful management, research underway to resolve them, and research that is planned by the NRMRL.

Sustainable systems theory: ecological and other aspects

While sustainability is generally associated with the definition of sustainable development given by the Brundtland Commission ‘Our common future (1987) Oxford University Press,’ namely ‘development that meets the needs of the present without compromising the ability of future generations to meet their own needs,’ it is important to recognize that a mathematical theory embodying these concepts would be immensely valuable in humanity's efforts to manage the environment. The concept of sustainability applies to integrated systems comprising humans and the rest of nature. The structures and operation of the human component (in terms of society, economy, law, etc.) must be such that these reinforce or promote the persistence of the structures and operation of the natural component (in terms of ecosystem trophic linkages, biodiversity, biogeochemical cycles, etc.), and vice versa. Thus, one of the challenges of sustainability research lies in linking measures of ecosystem functioning to the structure and operation of the associated social system. We propose that indicators based on Information Theory can bridge the natural and human system elements, and make sense of the disparate state variables of the system. Thus, in this paper we explore the use of Fisher Information, which is a statistical measure of variation, as an aggregating index for dynamic systems of many variables. We have developed a novel application of Fisher Information to time-series data of dynamic systems, which (borrowing from statistical mechanics) uses an ensemble average of the system dynamics. We demonstrate this methodology using an uncalibrated 5-trophic level, 12-compartment (species) food web model with an associated basic social system for the population of omnivores at the top of the food chain. The model has five functional groups: detritus, primary producers, herbivores, carnivores, and omnivores. In addition to a seasonal forcing function, perturbation scenarios involving each of the parts of the system are simulated so as to explore the sustainability of the system under various types of stress, including basic human behaviors, such as agriculture. Since Fisher Information is a measure of the variation, we hypothesize that it is an indicator of system order, and thus system sustainability. This work is part of a multidisciplinary group at the U.S. Environmental Protection Agency's National Risk Management Research Laboratory.

Sustainability: ecological, social, economic, technological, and systems perspectives

Sustainability is generally associated with a definition by the World Commission on Environment and Development, 1987: "... development that meets the needs of the present without compromising the ability of future generations to meet their own needs ..." However, there is no mathematical theory embodying these concepts, although one would be immensely valuable in humanity's efforts to manage the environment. The concept of sustainability applies to integrated systems comprising humans and the rest of nature; the structures and operation of the human component (society, economy, law, etc.) must be such that they reinforce the persistence of the structures and operation of the natural component (ecosystem trophic linkages, biodiversity, biogeochemical cycles, etc.). One of the challenges of sustainability research lies in linking measures of ecosystem functioning to the structure and operation of the associated social system. We review the nature of this complex system including its ecological, social, economic, and technological aspects, and propose an approach to assessing sustainability based on Information Theory that bridges the natural and human systems. These principles are then illustrated using a model system with an ecological food web linked to a rudimentary social system. This work is part of the efforts of a larger multidisciplinary group at the U.S. Environmental Protection Agency's National Risk Management Research Laboratory.

Development of a research strategy for integrated technology-based toxicological and chemical evaluation of complex mixtures of drinking water disinfection byproducts.

Chemical disinfection of water is a major public health triumph of the 20th century. Dramatic decreases in both morbidity and mortality of waterborne diseases are a direct result of water disinfection. With these important public health benefits comes low-level, chronic exposure to a very large number of disinfection byproducts (DBPs), chemicals formed through reaction of the chemical disinfectant with naturally occurring inorganic and organic material in the source water. This article provides an overview of joint research planning by scientists residing within the various organizations of the U.S. Environmental Protection Agency Office of Research and Development. The purpose is to address concerns related to potential health effects from exposure to DBPs that cannot be addressed directly from toxicological studies of individual DBPs or simple DBP mixtures. Two factors motivate the need for such an investigation of complex mixtures of DBPs: a) a significant amount of the material that makes up the total organic halide and total organic carbon portions of the DBPs has not been identified; and b) epidemiologic data, although not conclusive, are suggestive of potential developmental, reproductive, or carcinogenic health effects in humans exposed to DBPs. The plan is being developed and the experiments necessary to determine the feasibility of its implementation are being conducted by scientists from the National Health and Environmental Effects Research Laboratory, the National Risk Management Research Laboratory, the National Exposure Research Laboratory, and the National Center for Environmental Assessment.

American creosote site case study: Solidification/stabilization of dioxins, PCP, and creosote for $64 per cubic yard

AbstractSolidification/Stabilization (S/S) is a low‐cost remedial technology that has been used extensively for decades to treat soil contaminated with metals on Super fund sites. Increasingly, it is being used with success to remediate sites that contain higher molecular weight organic compounds. This case study describes the development of S/S formations and their application to remediate the American Creosote Superfund Site in Jackson, Tennessee.The U.S. EPA National Risk Management Research Laboratory conducted successful treatability tests of innovative solidification/stabilization (S/S) formulations to treat soils contaminated with dioxins, pentachlorophenol (PCP), and creosote from four wood preserving sites. Formulations developed during these studies were successful in reducing the mobility (leaching) of contaminants of concern by 95% to 99%. For one of these sites, the American Creosote Superfund site in Jackson, Tennessee, the U.S. EPA, in cooperation with the State of Tennessee, conducted a successful remediation of 45,000 cubic yards during 1998 and 1999. The costs to excavate, treat, replace, and cap soil contaminated with dioxin, PCP, and creosote averaged $64 per cubic yard (about $40 ton). Formulations, design, operations, performance specifications, and costs are presented in this paper.

Mercury control research: effects of fly ash and flue gas parameters on mercury speciation

Mercury Control Research: Effects of Fly Ash and Flue Gas Parameters on Mercury Speciation Chun Wai Lee and James D. Kilgroe U.S. Environmental Protection Agency National Risk Management Research Laboratory Research Triangle Park. NC S. Behrooz Ghorishi ARCADIS Geraghty & Miller, Inc. Research Triangle Park, NC In flue gas from combustion systems, mercury (Hg) is typically in the vapor phase at flue gas cleaning temperatures, and the control of Hg emissions is dependent on the specific Hg compounds that are present (speciation) and the type of air pollution devices employed. In dry and semi-dry scrubbing systems, the control of Hg emissions is dependent on the sorption of Hg by particulate matter (PM) which can be subsequently collected in a PM control device. In wet scrubbing systems, the principal mechanisms of control are the removal of soluble forms of Hg and the collection of particle-bound Hg. At combustion temperatures, Hg is believed to be predominantly in the form of elemental mercury (Hgo). As the flue gas is cooled, thermochemical equilibrium calculations indicate that Hgo is converted primarily to ionic mercury (Hg++) in the form of mercuric oxide (HgO) or mercuric chloride (HgCl2). Hgo is insoluble in water, but HgO has a low solubility while HgCl2 is highly soluble. The oxidation of Hgo to an ionic form depends on the temperature, the time-temperature proflle, the flue gas composition, the reaction kinetics, and the presence of solids that may catalyze reactions. Bench-scale experiments were conducted to study the effects of flue gas and fly ash parameters on the oxidation of HgOin simulated flue gases containing hydrogen chloride (Hel). Gas-phase studies indicated that the in-flight post-combustion oxidation of Hgo in the presence of HCI is very slow and proceeds at measurable rates only at high temperatures (>700 °C) and high HCI concentrations (>200 ppm). The presence of sulfur dioxide (S02) and water vapor in the simulated flue gas significantly inhibited the gas-phase oxidation of Hgo. On the other hand, a preliminary investigation indicated that the gas-phase reaction of Hgo with chlorine (Cl:z) is fast At 40°C and in the presence of 50 ppm C12, 100% of the input Hgo was oxidized to HgCl2 in less than 2 seconds, indicating that Cl2 is a much more active chlorinating agent than HCl. The effects of fly ash composition were investigated using a fixed-bed reactor containing different model fly ashes (simulated fly ash) consisting of mixtures of some major components found in coal and municipal waste combustor (MWC) fly ashes. Work to date has focused on the

Methodology and model for performance and cost comparison of innovative treatment technologies at wood preserving sites

AbstractWood preserving facilities have used a variety of compounds, including pentachlorophenol (PCP), creosote, and certain metals, to extend the useful life of wood products. Past operations and waste management practices resulted in soil and water contamination at a portion of the more than 700 wood preserving sites in the United States (EPA, 1997). Many of these sites are currently being addressed under federal, state, or voluntary cleanup programs. The U.S. Environmental Protection Agency (EPA) National Risk Management Research Laboratory (NRMRL) has responded to the need for information aimed at facilitating remediation of wood preserving sites by conducting treatability studies, issuing guidance, and preparing reports. This article presents a practical methodology and computer model for screening the performances and comparing the costs of seven innovative technologies that could be used for the treatment of contaminated soils at user‐specified wood preserving sites. The model incorporates a technology screening function and a cost‐estimating function developed from literature searches and vendor information solicited for this study. This article also provides background information on the derivation of various assumptions and default values used in the model, common contaminants at wood preserving sites, and recent trends in the cleanup of such sites. © 2001 John Wiley & Sons, Inc.