TP18 Assessing Ecosystem Services and Benefits|
Tuesday, 15 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall
TP191 (MAY-1117-838441) Effects of stream restoration on ground water nitrate at Minebank Run, an urban stream in the Chesapeake Bay watershed.
Start time: 8:00 AM
Mayer, P1, Striz, E1, Groffman, P2, Doheny, E3, Shedlock, R3, 1 US Environmental Protection Agency, Ada, OK, USA2 Institute of Ecosystem Studies, Millbrook, NY, USA3 US Geological Survey, Baltimore, MD
Elevated nitrate levels in streams and ground water pose human and ecological threats. Microbial denitrification removes nitrate from ground water but requires anaerobic (saturated) conditions and adequate supply of dissolved organic carbon from detritus and organic soils. Conditions favorable for denitrification may be under geomorphic control. For example, stream incision due to urbanization may cause a disconnection between the stream channel and the adjacent floodplain thereby inhibiting denitrification and/or promoting nitrification. We examined the effects of geomorphic restoration (e.g. bank re-shaping, bank reinforcement, channel meanders, energy dissipation structures) on ground water nitrate and carbon of Minebank Run, a restored urban stream in the Chesapeake Bay watershed. Nitrate was inversely related to dissolved organic carbon in ground water, suggesting control of denitrification by carbon availability to microbial denitrifyers. Nitrate concentration was positively related to dissolved oxygen in ground water, suggesting that lower base flow and increased hydraulic residence times, promoted conditions (e.g. lower dissolved oxygen, prolonged mixing with dissolved organic carbon) that removed N from the stream. Nitrate was lower in restored reaches of the stream in which incised banks had been reconstructed, suggesting that stream restoration methods that reconnect flood plains to stream channels can promote ground water nitrate removal and, thereby, improve stream water quality.
TP192 (PAS-1118-217421) Scientific and aesthetic issues in ecological habitat restoration.
Start time: 8:00 AM
Pastorok, R.1, Sampson, J.1, 1 Integral Consulting Inc, Mercer Island, WA, USA
Ecological habitat restoration is an emerging field requiring integration of both scientific and aesthetic disciplines. Habitat restoration projects are commonly located within urban or suburban landscapes, where support of human services as well as ecological functions is desirable. Consequently, restoration designs should be developed within the context of a multiobjective planning process that considers landscape context, ecological functions and supporting structures, often competing risks (e.g., invasive species, eutrophication, chemical toxicity), spatial heterogeneity, natural disturbances, and relationship to human communities. Aesthetics as well as ecological function emerge at various spatial scales in environmental systems, from micro-habitat to regional and global levels. In Washington State, the heterogeneity of intertidal landscapes at Tatoosh Island illustrates the influence of natural disturbance regimes in producing dynamic aesthetically pleasing patterns while maintaining macrospecies diversity important for ecological functions. At a regional scale, variation in physical and climatic environments from the Washington State coast to the interior basin produces apparently stable macro-patterns in habitat types across the state. Relationships between pattern and process in ecological systems have been poorly quantified despite the common belief that ecological function or support of human services is related to ecological structure such as habitat fragmentation or species diversity. Sometimes aesthetics are congruent with structural integrity of habitat (e.g., bird species diversity vs. foliage height diversity), but this may not always be the case. Successful restoration of ecological systems requires: 1) a variable design approach; i.e., incorporation of high habitat diversity and variability around a fixed apparently optimal design; 2) a safe-fail approach or planning for failure of supposedly optimal designs, combined with adaptive management; and 3) integration with human communities via aesthetics and environmental stewardship.
TP193 (ROY-1117-820290) Application of an Ecological Services Analysis under the Texas Risk Reduction Rule.
Start time: 8:00 AM
Roy, M1, 1 URS Corporation, Austin, Texas, USA
An ecological services analysis (ESA) is a risk management option under the Texas Commission on Environmental Quality (TCEQ) Texas Risk Reduction Program (TRRP) 30 TAC 350. An ESA is required when contaminants are to be left in place above ecological criteria. The ESA considers the present and predicted ecological services of an affected property, as well as the beneficial and/or detrimental effects on services associated with ecological risks. According to TRRP, key tenets of the ESA are, (1) even impaired habitats can provide valuable ecological services, (2) the environment is an ecosystem that extends beyond the perimeter of an affected property, and (3) reduction in services provided by habitat in one location can be offset by a corresponding increase in services elsewhere. The first ESA to be approved in Texas was for a City of Austin (CoA) project. An on-site two-acre pond had received runoff from the surrounding landscape, and organochlorine pesticides were in sediments. An ecological risk assessment (ERA) was conducted and approved by the TCEQ. The natural resource trustees who participated in this process included TCEQ and the Texas Parks and Wildlife Department (TPWD). The ESA included the ERA conclusions and interpretation of how potential risks relates to ecological resource damage. A CoA surface water retention pond located in the city was used as compensation for the potential ecological service loss from the pesticides remaining in the sediments of the two-acre on site pond. A Habitat Equivalency Analysis (HEA) was included in the ESA document to justify this alternative. Other alternatives included removing or lining the pond. Both alternatives removed all habitats. It was only through communication efforts that all parties were able to understand each perspective and to reach a cooperative solution. Ecological and societal resources were increased, adding no additional costs for remediation.
TP195 (VON-1117-723691) Use of Stated Preference Methods to Value the Benefits of Ecological Risk Reductions: A Case Study of Exposure to Polychlorinated Biphenyls.
Start time: 8:00 AM
von Stackelberg, K1, 2, Hammitt, J2, 1 Menzie-Cura & Associates, Inc., Winchester, MA, USA2 Harvard Center for Risk Analysis, Boston, MA, USA
A risk assessment framework provides a basis for comparing potential risks or risk reductions across different policy alternatives, site-specific management strategies, or for evaluating permit applications. In many cases, it is beneficial, indeed necessary, to quantify the potential benefits of risk reductions. This is not typically straightforward for ecological risks in particular, since the benefits generally involve passive use values for which there are no observable markets. Most ecological benefits do not lend themselves to quantification using revealed preference methods. Although benefits do not necessarily require monetization, there are distinct advantages for quantifying benefits in terms of money. In particular, money is a convenient common metric across disparate endpoints (e.g., human health and ecological), allows for a direct comparison to predicted costs of the management alternatives, and allows for the incorporation of passive use values such as existence and bequest value. In the absence of observable markets for the endpoints of interest, stated preference methods that rely on individuals making hypothetical choices would seem to offer an approach. Although there are legitimate criticisms of stated preference methods, in some cases they may offer the only reasonable alternative to capturing the monetary value of benefits of regulatory actions. We present the results of a contingent valuation (CV) survey developed specifically to elicit willingness to pay values from the general public for risks and endpoints associated with exposure to polychlorinated biphenyls (PCBs) via fish ingestion. An ecological risk assessment framework forms the basis of the endpoints valued in the CV in order to evaluate the feasibility of monetizing the benefits of ecological risk reductions using stated preference methods.
TP196 (BRU-1116-603512) Expanded conceptual models as an organizing framework for ecological benefits assessment.
Start time: 8:00 AM
Bruins, R1, Heberling, M1, 1 U.S. Environmental Protection Agency, Cincinnati, OH, USA
The conceptual models that typically are used to organize ecological risk assessments are diagrammatic depictions of risk hypotheses — proposed explanations of relationships between sources, stressors, exposure pathways, and effects on ecological assessment endpoints. To assess ecological benefits, risk hypotheses must be expanded to include the changes in ecosystem services that will be associated with the changes in those endpoints. Further, since the evaluation of management alternatives (such as project alternatives for a local stream restoration or options for a national regulation) usually is the goal of benefits assessment, risk management hypotheses are needed as well. These are proposed explanations of how management alternatives will affect sources, exposures, effects and services. We show how expanded conceptual models may be used both to guide technical evaluation of alternatives and as a communication tool, helping stakeholders appreciate the relative merits of management and restoration alternatives, both in terms of the costs of those actions and their expected ecological benefits.
TP197 (MCC-1117-830469) NEBA for Forested Wetland to Support Feasibility Study at the Jasper Creosote Company Superfund Site.
Start time: 8:00 AM
McCarthy, C1, Nicolette, J2, Faught, B1, Sciera, K 3, Sullivan, R3, 1 CH2M HILL, Houston, TX, USA2 CH2M HILL, Atlanta, GA, USA3 U.S.E.P.A, Dallas, TX, USA
A Net Environmental Benefit Analysis (NEBA) was conducted to compare remedial alternatives as part of the Feasibility Study (FS) for the Jasper Creosote Company Superfund Site located in Jasper, Texas. The remedial investigation (RI) for the Site demonstrated risks to adolescent human recreationists, wildlife, and benthic organisms exposed to soil/sediment in a seasonally inundated forested wetland with elevated levels of PAHs. After several remedial alternatives were developed, a NEBA was used to compare the impacts of the alternatives on the existing ecosystem. The wetland provides habitat for amphibians, reptiles, and small mammals. It also acts as a natural filter system breaking down PAHs and other organic by-products of the creosote plant that once operated upstream of the wetland, before draining into Big Sandy Creek 800 feet downstream of the Site. The natural filter system was considered the ecological service currently provided by the wetland that would be most impacted by remedial options. The following remedial alternatives were compared using NEBA to determine which had the least impact to the services currently provided by the wetland (i.e., the filtering capacity) in comparison to benefits provided: no action, complete removal of human and ecological risk-based PRG exceedances, complete removal of human and ecological risk-based PRG exceedances with enhancements, removal of human health risk-based PRG exceedances, removal of human health risk-based PRG exceedances with enhancements, and Hot Spot removal. Next to no action, hot spot removal was determined to have the least impact to the existing services provided by the wetland. The results of the NEBA along with several other considerations were used to determine the final remedy for the Site. Other considerations included cost, amount of potential waste left in place, potential ecological services gained, and time to implement each alternative relative to the project schedule.
TP199 (WEI-1117-842742) More than a gut feeling; use of a resource economic model to support site closure.
Start time: 8:00 AM
Weier, J1, Petron, S1, Corl, E2, Reisch, T2, 1 CH2M HILL, Boston, MA, USA2 NAVFAC Atlantic, Norfolk, VA, USA
At the former New Gosport Landfill on Paradise Creek, Norfolk Naval Shipyard, Portsmouth, Virginia, the Navy implemented a removal action and excavated 55,000 tons of contaminated soil/sediment. In place of the excavated material, a new 1.9-acre tidal wetland was created. As part of a Technical Memorandum evaluating residual risk, a net environmental benefits analysis (NEBA) was conducted to estimate the net gain or loss of estuarine ecological services associated with the removal action and restoration. The NEBA, which involved the use of Habitat Equivalency Analysis (HEA), compared the ecological services over time provided by habitats within the study area under the no action and removal scenarios. The effect of contamination on estuarine services was also addressed as part of the analysis. The results of the NEBA indicated that the removal action and creation of Spartina marsh had increased ecological service flows by almost 40%. These results documented that residual risk was not causing a significant adverse impact, and that the actions taken had considerably improved the ecosystem, offsetting any residual risk. The NEBA was approved by the Norfolk Naval Shipyard partnering team, which includes representatives of the Navy, US Environmental Protection Agency, and Virginia Department of Environmental Quality. The NEBA provided this stakeholder group the information it needed to determine that no further investigation or remediation of 3.2 acres of wetland habitat was necessary and that site closure was warranted.
TP200 (OWE-1117-811768) Progress on improving ecological benefits assessment in the U.S. Environmental Protection Agency.
Start time: 8:00 AM
Owens, N1, Munns, W1, Wheeler, W1, Bruins, R1, Lovell, S1, Newbold, S1, Norton, D1, Corona, J, 1 US EPA
Ecological benefits are defined as improvements in human well-being that result from actions to protect or restore ecosystems. Ecological benefits assessment (EBA) is analysis that quantifies those improvements and monetizes them when possible. Enhancing the quality of EBA is important for ensuring that environmental management measures, including both regulatory and nonregulatory programs, are effective. The U.S. Environmental Protection Agency has developed a new strategy for improving the ecological research, economic research and institutional arrangements that form the basis of its EBA capabilities. This presentation will review the recommendations contained in the strategy and discuss the Agency's approach for implementing those recommendations.