Environmental Perspectives SUMMER 2008

Transcription

1 Environmental Perspectives SUMMER 2008 page Feature Article 1 Decision Support for Environmental Remediation and Restoration 2 3 Next Issue 4 New Faces 5 Publications 6 Conferences & Presentations 7 About Exponent 8 9 A P U B L I C AT I O N OF EXPONENT S E N V I R O N M E N TA L AND ECOSCIENCES PRACTICES

2 Decision Support for Environmental Remediation Environmental decision-making raises many complex technical and social issues that must be addressed by multiple stakeholders. These stakeholders are guided by conflicting sets of values, regulatory constraints, and management goals, and decision makers NEBA is an approach for evaluating management alternatives in terms of ecosystem services rather than focusing on a bright-line comparison of risk or concentration. While NEBA is usually considered as a process for evaluating alternatives on the basis of Betsy Henry, Ph.D. often have imperfect information on which to base ecosystem services, it can also provide an objective Trina von Stackelberg, Sc.D. decisions. To further complicate matters, environmental method for attributing value to various ecosystem quality is usually affected by multiple stressors and services, which can be useful in communicating the the risk of remedy may be greater than the risk of impacts of remedial alternatives across stakeholders. contamination. Determining the best management The concept originates from a growing awareness that alternative is never a straightforward process because invasive remedial measures such as dredging often it necessarily involves making a variety of decisions do not deliver the expected benefits of risk reduction requiring tradeoffs, with varying levels of importance relative to the associated environmental costs (NRC to affected stakeholders. 2007); from a recognition that contaminated sediment sites may require a range of remedial options The decision process can benefit from using a tailored to site-specific environmental conditions systematic decision support system (DSS) to evaluate (U.S. EPA 2005); and from insights that management management alternatives that consider all the potential decisions (including sediment remediation) can and risk tradeoffs (Menzie et al. in press). One particular should be framed within the larger context of the approach to evaluating management alternatives watershed and the stressors specific to that system. in terms of ecosystem services is net environmental The NEBA approach assumes that the goal of any benefits analysis (NEBA; Efroymson et al. 2003). site-specific management alternative is the cost-effective maximization of environmental quality and conditions.

3 While Superfund focuses on the contamination present within the system, U.S. EPA (2005) guidance highlights the importance of considering the nature of the watershed as part of remedial decision-making. The U.S. Environmental Protection Agency (EPA) has also initiated an effort to understand how multiple stressors influence ecological conditions and how insights gained from cumulative risk or multiple-stressor approaches can inform management decisions. To that end, EPA has published a framework for cumulative risk assessment and generated a series of issue papers, one of which outlines approaches for evaluating multiple stressor problems such as exist in large urban watersheds (Menzie et al. 2007). The approaches described in this article are consistent with the anticipated future direction of the Superfund Program as it relates to contaminated sediments, and with EPA s emerging policies related to management of watersheds where there are multiple stressors. Ultimately, the aim of these approaches is to provide a framework that can lead to outcomes that are environmentally beneficial. The NEBA approach assumes that the goal of any site-specific management alternative is the cost-effective maximization of environmental quality and conditions. NEBA provides an approach for evaluating management alternatives in terms of the overall ecosystem services they provide in the short- and long-term. Contaminants in the environment represent chemical stressors in an ecosystem. There can be other kinds of stressors, including physical stressors, as a result of modification to an ecosystem through implementation of a remedial alternative. Further, there may be chemical, physical, and biological stressors present within the system that are unrelated to the presence of contamination or the physical impacts of remedial alternatives. While NEBA is usually considered as a process for evaluating alternatives on the basis of ecosystem services, it can also provide an objective method for attributing value to various ecosystem services. The NEBA approach is particularly relevant for sites where remediation may cause environmental damage, where remediation may not significantly reduce ecological risk, and/or where the costs of remediation seem greater than the benefits of remediation in terms of risk reduction. The starting point is to identify those attributes of the site that are the focus of management goals (assessment endpoints). This involves holding a series of conversations with regulators to identify the ecosystem attributes that are considered worth protecting and that represent the focus of management efforts. This iterative dialogue will establish the conceptual overview of the NEBA by making explicit those ecosystem attributes that are of primary concern. A conceptual site model (CSM) is then developed that describes the relationship between assessment endpoints and various stressors. Figure 1 shows an example of a CSM. The analysis proceeds by quantifying specifically how the alternatives under

4 SOURCE STRESSOR HABITAT ASSESSMENT ENDPOINTS consideration will influence the assessment endpoints. Atmospheric deposition Contaminants in sediment Creeks and ditches Benthic Invertebrate Populations Fish/Shellfish Populations Amphibian/Reptile Populations Avian Populations Mammalian Populations Recreational Visitors Anglers The results are converted to rankings, tabulated in a matrix across alternatives, and then summed. The alternatives can then be ranked according to the number of points each receives. Efroymson et al. (2003) provide one of the earliest examples of the approach. Point sources (contaminated sites, NJPDES permitted discharges) Nonpoint sources (runoff) Development Contaminants in water Turbidity Nutrient enrichment Habitat fragmentation Channelization Figure 1. Conceptual site model for an estuarine marsh Marshes and swamps Riparian zone Forested wetland Upland In a typical site-specific evaluation, human health and ecological risk assessments quantify the impact (ideally, the probability) of adverse effects occurring. Different management alternatives can decrease these risks, but generally at a physical cost (e.g., destruction of habitat, green-space, etc.). In addition, while the management alternative is being implemented, there is often a significant disruption to individuals living nearby (e.g., dredges operating on a backyard river). As stated earlier, the goal of any site-specific management alternative should be the cost-effective maximization of environmental quality and conditions. Consequently, the most appropriate analysis should comparatively address both risks of contamination as well as risk of remedy in an effort to determine which alternative provides the most environmental benefits.

5 For example, in addition to evaluating potential human health and ecological risks, it is possible to also evaluate in a formal multi-critical decision analysis (MCDA), which would allow particular endpoints to be weighted in 40 habitat quality using techniques commonly employed in NRDAs (such as habitat equivalency analysis). Costs, aesthetic considerations and value, and human use values are other attributes important to stakeholders. Figure 2 provides a graphical representation of the results of a different ways (for example, stakeholders have expressed that minimizing dsay losses should be the priority). To interpret these results, the original units can be converted to rankings and summed across alternatives. HUMAN HEALTH RISK ECOLOGICAL RISK REMEDIAL COST (millions of dollars) hypothetical NEBA that considers all of these attributes. Doing that for all criteria except cost (assuming that costs The yellow circles and teal circles depict human health and ecological risks, respectively, with corresponding costs for each alternative depicted by the green bars. Ecological and human services (aesthetic and recreational) are depicted using yellow and teal bars, respectively. Ecological services are estimated using discounted service acre years (dsays, following the habitat equivalency analysis framework), although might be considered separately because of stakeholder resistance) results in Alternative 3 as being preferred based on ranking alone, followed by Alternative 1, No Action, Alternative 4, and finally, Alternative 2. If costs are ranked and included in the matrix, the preferred alternative switches to 1, followed by 3 and No Action, Alternative 4 and finally, Alternative 2. In addition, each of the rankings can be weighted according to stakeholder preferences (or, alternatively, a ranking ECOLOGICAL SERVICE LOSS (dsays) 0 5,000 10,000 15,000 20,000 No Action Alternative 1 Alternative 2 Alternative 3 Alternative HUMAN USE VALUE LOSS (millions of dollars) other metrics are possible and should be encouraged, of alternatives based on stakeholder consensus) to particularly as measurement and valuation of changes in ecosystem services becomes more established. In some NEBAs, clear cut-offs across alternatives will explicitly incorporate that criterion. If it is possible to express each of the results in Figure 2. Example results of a NEBA showing predicted risk, cost, and service loss across remedial alternatives (adapted from Nicolette and Hutcheson 2004). be obvious, while others require additional analysis to Figure 1 as a distribution, then MCDA software determine which management alternative maximizes and methods would allow those distributions to be benefits overall. The results are well-suited for inclusion incorporated directly in the analysis.

6 Another way to consider net environmental benefits is shown in Figure 3. This figure depicts net A NEBA provides a framework for comparing ecosystem service losses and benefits across Dr. Betsy Henry is a Senior Managing Scientist in Exponent s Environmental Sciences practice, and environmental services versus cost over time. Under this scenario, it is possible to compare the area under management alternatives. For example, NEBA can be used to evaluate the service losses imposed by the has been working in the field of contaminant transport and fate with an emphasis on mercury for 20 years. the curve for service benefits and losses (which could, partial removal of a forested wetland for remediation She earned a B.S. in Agronomy from Colorado for example, be monetized) for each alternative. of a contaminant. Although contaminant risks State University in 1985 and a Ph.D. in Engineering ECOSYSTEM SERVICES Remedial Alternative 1 Monitored Recovery Environmental service loss of remediation Environmental benefit of remediation decrease, there is also significant habitat loss that, when compared to the cost of remediation, may not be offset by the decrease in risk. The opposite may be true for a site for which initial ecosystem services are very low, and would increase over time following remediation. Sciences from Harvard University in 1992, with a dissertation on mercury methylation in the environment. Her broad interests include environmental biogeochemistry, ecology, and risk management. (henryb@exponent.com) Dr. Katherine von Stackelberg is a Managing TIME A common criticism of NEBA expressed by regulators Scientist in Exponent s Ecosciences practice, and is Figure 3: Example of the tradeoff between service benefit and loss across alternatives under consideration is that this is simply a method for avoiding potentially costly cleanups. Proponents of the method argue also a Research Manager at the Harvard Center for Risk Analysis. She has spent more than 15 years that removing all contamination to some low risk- developing risk-based tools and approaches to support In this case, the area under the curve for the remedial based, or even background, number can cause environmental decision-making at contaminated alternative exceeds that of monitored recovery, more environmental service losses than are created. sediment sites. Dr. von Stackelberg was the technical suggesting that the alternative might be justified. Shouldn t the goal of all management actions taken lead and project manager for development of a However, the difference is small, and incorporating at environmentally-contaminated sites be a net probabilistic bioaccumulation model and ecological upper and lower confidence bands over the benefit/ increase in environmental benefits? NEBA provides risk assessment on behalf of EPA for the Hudson River loss profile might suggest a different outcome. one framework for quantitatively evaluating remedial Superfund Site. She received her A.B, Sc.M., and alternatives by that metric. Sc.D. from Harvard University. (kvon@exponent.com)

7 References Efroymson, R.A., J.P. Nicolette, and G.W. Suter II A framework for net environmental benefit analysis for remediation or restoration of petroleumcontaminated sites. ORNL/TM-2003/17. Oak Ridge National Laboratory, Environmental Sciences Division. Menzie, C.A., Booth, P., Law, S., and K. von Stackelberg Use of decision support systems to address contaminated coastal sediments: Experience in the United States. In Decision Support Systems for Risk Based Management of Contaminated Sites. Marcomini, A., Suter, G.W. and A. Critto, Eds. Springer-Verlag. In press. Menzie, C.A., M.M. MacDonell, and M. Mumtaz A phased approach for assessing combined effects from multiple stressors. Environ. Health Perspect. 115:5: Nicolette JP, Hutcheson K (2004) Use of a net environmental benefits analysis (NEBA) approach for remedial decision making at two BRAC sites. CH2M Hill and Marstel-Day Associates. Presentation at the 30th Environmental and Energy Symposium & Exhibition 5 8 April 2004, San Diego, CA, enviro.html Modeling Global Climate Change Clearly the hottest environmental topic of the decade, and possibly of the century, is that of global climate change. How is it possible to forecast climate change 50 years into the future, but not be able to forecast tomorrow s weather accurately? How accurate is global climate modeling? Is there one dominant model, or are there many models? What are the strengths and weaknesses of global climate modeling? Which parameters are considered and, just as important, which parameters are ignored? Climate change is being discussed at political, Panel on Climate Change (IPCC) has to say about the modeling it uses as the basis for its major conclusions that the Earth s climate is warming and that the warming is most likely the result of anthropogenic greenhouse gas emissions. Using the IPCC s selfassessment, we will outline those technical issues for which additional research is needed. NRC Sediment dredging at Superfund sites: Assessing the effectiveness. National Research Council, National Academy Press. U.S. EPA Contaminated sediment remediation guidance for hazardous waste sites. U.S. Environmental Protection Agency. scientific, and social levels around the world. The next issue of Environmental Perspectives will delve into one aspect of the global warming issue. We will explore questions, such as those above, that are related to the computer modeling used to assess global climate change. We will focus on what the Intergovernmental

8 New Faces Robert Montgomery, Ph.D. Senior Manager, Environmental Sciences, Washington DC The focus of Dr. Montgomery s 25 years of successful international experience has been helping privatesector companies and financial institutions manage environmental, social, health and safety, and labor aspects of their businesses to ensure sustainable development and successful operations. Dr. Montgomery specializes in large-scale complex and controversial international projects in a broad range of sectors, including oil and gas, infrastructure (e.g., energy, transportation, water and sanitation, telecommunications), construction, and financial institutions, having performed more than 300 projects across 35 countries in North and South America, Europe, Africa, and the Middle East. Jaana Pietari, Ph.D. Senior Scientist Environmental Sciences, Bellevue, WA Dr. Pietari s expertise is in the fate and biological treatment of chlorinated compounds including tetrachloroethene (PCE) and pentachlorophenol (PCP), the analytical chemistry of polychlorinated biphenyls (PCBs), and biological water and wastewater treatment. She has more than 10 years of experience conducting environmental engineering and science research in academic and regulatory settings, in addition to environmental consulting experience. Stephen Michael Mudge, Ph.D. Managing Scientist, Environmental Sciences, Harrogate, UK Dr. Mudge specializes in the identification of sources of contaminants in the environment and their apportionment to potential polluters. He has worked on tracking sewage-derived materials in marine and estuarine environments and has published papers and book chapters on the subject. He has continued to expand the use of multivariate statistical methods such as PCA and PLS in quantitative source apportionment. Dr. Mudge earned a Ph.D. in Marine Science from Bangor University, UK, and spent 6 years in postdoctoral research at Lancaster University investigating the geochemistry of radionuclides in the environment, including plutonium and polonium 210 discharged from a metal smelter. Publications Becker DS, Ginn TC. Critical evaluation of the sediment effect concentrations for polychlorinated biphenyls. Integ Environ Assess Manage 2008; 4(2): Bessinger BA, Redding B, Lowney YW. Comments on Release of Arsenic to the Environment from CCA-Treated Wood. 2. Leaching and Speciation during Disposal. Environ Sci Technol 2007; 41(1): Bigham G, Chan W, Dekermenjian M, Reza A. Indoor concentrations of mercury vapor following various spill scenarios. Environmental Forensics; 2008, in press. Booth P, Gard N, Law S, Davis R. Sustainability: Considerations for including eco-assets in a company s bottom line. American Bar Association Climate Change, Sustainable Development, and Ecosystems Committee Newsletter 2007; 11(1):7 11. Johnson KR, Jepson PC, Jenkins JJ. Esfenvalerateinduced case-abandonment adversely impacts Brachycentrus americanus behavior and survival. Environ Toxicol Chem 2008; 27(2):

9 Montgomery RH. Managing risk and adding value (environmental and social risk management). Environmental Finance, March Montgomery RH, Palma A, Hoagland-Grey H. Community investment programs in developing country infrastructure projects. ASCE Journal of Infrastructure Systems, in press. Shock SS, Bessinger BA, Lowney YW, Clark JL. Assessment of the solubility and bioaccessibility of barium and aluminum in soils affected by mine dust deposition. Environ Sci Technol 2007; 41(13): Conferences and Presentations Boehm P, Saba T. Using chemical forensics and other lines of evidence to distinguish PAH contributions from different pyrogenic sources to the sediments of the Hylebos Waterway Superfund Site A CERCLA and MTCA cost recovery case. SMWG Spring Sponsor Forum. Kalamazoo, MI, April 29 30, Chan WR, Levy JA, Murphy BL. Assessment of downwind exposure from remediation of former MGP sites. Land and Groundwater Area Council Meeting, Electric Power Research Institute, Scottsdale, AZ, February 11, Murphy B, O Reilly K. Reconstructing doses and exposures using environmental forensic methods. 37th Conference on Environmental Law, ABA Section of Environment, Energy, and Resources, Keystone, CO, March 13 16, 2008 Noggle JJ, Shock SS, Bloom N, Yost LJ. Evaluation of potential for mercury volatilization from gypsum products using flux chamber tests. Poster presented at the SETAC 28th Annual Meeting, Milwaukee, WI, November 11 15, Palmquist KR, Jenkins JJ, Jepson PC. Impact of aquatic insects life stage and emergence strategy on sensitivity to esfenvalerate exposure. Presented at the Pacific Branch Society of Environmental Toxicology and Chemistry Meeting, March 29, 2008, and at the North American Benthological Society Meeting, May 29, 2008 Flowers T, Deardorff T. The role of wetlands as a viable treatment technology for developing nations. World Environmental & Water Resources Congress, Honolulu, HI, May 12 16, Yost LJ, Shock SS, Noggle JJ. Lack of complete exposure pathways for metals in natural and FGD gypsum. Poster presented at the SETAC 28th Annual Meeting, Milwaukee, WI, November 11 15, Mesard PM, Deardorff TL. Stormwater management during construction A technical perspective. American Bar Association Toxic Tort Environmental Law Conference, Phoenix, AZ, April 10 12, 2008.

10 Contact: Paul D. Boehm, Ph.D. Principal Scientist and Group Vice President, Environmental Group (978) About Exponent Exponent is a leading engineering and scientific consulting firm dedicated to providing solutions to complex problems. To learn more about Exponent s Ecological, and Environmental capabilities listed below, click here. Environmental & Earth Sciences Air Quality Bioavailability & Exposure Assessment Chemical Fate & Transport Contaminated Sediments Assessment & Management Environmental Chemistry & Geochemistry Environmental Cost Consulting Feedback: Tell us what you like about this issue, or how we can help you. Please visit our website,, for information on all of our consulting services. Ecological & Biological Sciences Aquatic & Terrestrial Biology Bioavailability & Exposure Assessment Contaminated Sediments Assessment & Management Ecological & Environmental Risk Assessment Eco-Sustainability & Ecological Services Assessment Environmental Engineering Environmental Forensics Geochemical & Operational Consulting Greenhouse Gas and Climate Change Hydrogeology Management & Recycling/Solid & Hazardous Wastes, Including Landfills (888) 656-EXPO Endangered Species Oil Spill Assessment info@exponent.com with 19 regional and 4 international offices Environmental Assessment of Technologies & Products Environmental Modeling & Risk Assessment Geospatial & Landscape Analysis Product Stewardship Site Investigation & Remediation Consulting Surface Water Contaminant Transport Natural Resource Damage Assessment Technical Support Services to Financial Transactions Credits Oil Spill Assessment Product Stewardship Wetlands Assessment & Construction For more information on other Exponent capabilities, please visit our website,. Contributing writers: Betsy Henry, Trina von Stackelberg, and Julian Levy Editor: Patti Warden Design/Layout: Betty Dowd