Extending the Life Cycle Methodology to Cover Impacts of Land Use Systems on the Water Balance (7 pp)

Goal, Scope and Background Whilst initially designed for industrial production systems, environmental life cycle assessment (LCA) has recently been increasingly applied to agriculture and forestry projects. Several authors suggested that the standard LCA methodology needs to be refined to cover the particularities of agri- and silvicultural production systems. Until now, water quantity received little attention in these methodological revisions, notwithstanding the well-known impact of agriculture and forestry on issues like water availability, drought and flood risk. This paper proposes an add-on to existing LCA methods in the form of an indicator set that integrates water quantity impacts of agri- and silvicultural production. Method First, system boundaries are discussed in order to identify the water flows between the production system and the environment. These flows are attributed to impact categories, linked to environmental burdens and to the areas of protection. Appropriate indicators are selected for each potential burden. Results and Discussion At the present, two input related impact categories deal with water quantity: Abiotic resource depletion and land use. The list of output related impact categories presented by Udo de Haes et al. (1999) does not include water quantity impacts like flood and drought risk. A new impact category “regional water balance” is introduced to cover these risks. Exceedance probabilities are used as indicators for these temporal variations in streamflow. Conclusion and Outlook The method presented in this paper can bring a life cycle assessment closer to real world concerns. The main drawback, however, is the increasing data requirement that might hinder the feasibility of the method. Future research should focus on this problem, for instance by applying a relatively simple numerical model that can calculate the indicator scores from more easily accessible data.     

Country-dependent Characterisation Factors for Acidification in Europe - A Critical Evaluation (7 pp)

Goal, Scope and Background Country-dependent characterisation factors for acidification have been derived for use in life cycle assessments to describe the effect on ecosystem protection of a change in national emissions. They have recently also been used in support of European air pollution abatement policies and related cost benefit analyses. We demonstrate that the characterisation factors as calculated to date are unstable due to being derived from the non-smooth and highly varying part of the underlying emission-impact functions. The purpose of this paper is to discuss the currently available characterisation factors and to propose a modification that makes use of the full range of the underlying functions. Method The characterisation factors derived in this paper are based on updates of data used to support European air pollution agreements under the UNECE Convention on Long-range Transboundary Air Pollution (LRTAP) and the European Commission. The focus in this paper is on the analysis of characterisation factors for acidification. The analysis of characterisation factors for terrestrial eutrophication from nitrogen compounds is a simple extension of the methods described here. The analysis is conducted for 25 European nations, i.e. for 23 EU countries plus Norway and Switzerland; Cyprus and Malta are excluded due to lack of data on critical loads. Results and Conclusions We show that a linear model which is calibrated to emission changes of –50% is generally more reliable than characterisation factors which are based on emission changes of plus or minus 10%. Application of these characterisation factors are justified for emission reductions up to 30% in total European emissions, compared to 2000. This is within the range of currently agreed upon emission reductions in 2010 relative to 2000. Therefore, characterisation factors can be used in LCA as well as for the support of the revision of existing European air pollution agreements.     

Life Cycle Assessment of Kerosene Used in Aviation (8 pp)

Goal, Scope, and Background The main goal of the study is a comprehensive life cycle assessment of kerosene produced in a refinery located in Thessaloniki (Greece) and used in a commercial jet aircraft. Methods The Eco-Indicator 95 weighting method is used for the purpose of this study. The Eco-Indicator is a method of aggregation (or, as described in ISO draft 14042, 'weighting through categories') that leads to a single score. In the Eco-indicator method, the weighing factor (We) applied to an environmental impact index (greenhouse effect, ozone depletion, etc.) stems from the 'main' damage caused by this environmental impact. Results and Discussion The dominant source of greenhouse gas emissions is from kerosene combustion in aircraft turbines during air transportation, which contributes 99.5% of the total CO2 emissions. The extraction and refinery process of crude oil contribute by around 0.22% to the GWP. This is a logical outcome considering that these processes are very energy intensive. Transportation of crude oil and kerosene have little or no contribution to this impact category. The main source of CFC-11 equivalent emissions is refining of crude oil. These emissions derive from emissions that result from electricity production that is used during the operation of the refinery. NOx emissions contribute the most to the acidification followed by SO2 emissions. The main source is the use process in a commercial jet aircraft, which contributes approximately 96.04% to the total equivalent emissions. The refinery process of crude oil contributes by 2.11% mainly by producing SO2 emissions. This is due to the relative high content of sulphur in the input flows of these processes (crude oil) that results to the production of large amount of SO2. Transportation of crude oil by sea (0.76%) produces large amount of SO2 and NOx due to combustion of low quality liquid fuels (heavy fuel oil). High air emissions of NOx during kerosene combustion result in the high contribution of this subsystem to the eutrophication effect. Also, water emissions with high nitrous content during the refining and extraction of crude oil process have a big impact to the water eutrophication impact category. Conclusion The major environmental impact from the life cycle of kerosene is the acidification effect, followed by the greenhouse effect. The summer smog and eutrophication effect have much less severe effect. The main contributor is the combustion of kerosene to a commercial jet aircraft. Excluding the use phase, the refining process appears to be the most polluting process during kerosene's life cycle. This is due to the fact that the refining process is a very complicated energy intensive process that produces large amounts and variety of pollutant substances. Extraction and transportation of crude oil and kerosene equally contribute to the environmental impacts of the kerosene cycle, but at much lower level than the refining process. Recommendation and Perspective The study indicates a need for a more detailed analysis of the refining process which has a very high contribution to the total equivalent emissions of the acidification effect and to the total impact score of the system (excluding the combustion of kerosene). This is due to the relative high content of sulphur in the input flows of these processes (crude oil) that results to the production of large amount of SO2.     

Characterisation and Normalisation Factors for Life Cycle Impact Assessment Mined Abiotic Resources Categories in South Africa: The manufacturing of catalytic converter exhaust systems as a case study (10 pp)

Goal and Background Current Life Cycle Impact Assessment (LCIA) procedures have demonstrated certain limitations in the South African manufacturing industry. The aim of this paper is to propose new characterisation and normalisation factors for classified mined abiotic resource depletion categories in the South African context. These factors should reflect the importance of mined resources as they relate to region-specific resource depletion. The method can also be applied to determine global factors. Methods The reserve base (as in 2001) of the most commonly produced minerals in South Africa is used as basis to determine characterisation factors for a non-renewable mineral resources category. The average production of these minerals from 1991 to 2000 is compared to economically Demonstrated and Demonstrated Marginal Reserves (and not ultimate reserves) to obtain the characterisation factors in equivalence units, with platinum as the reference mineral. Similarly, for a non-renewable energy resources category, coal is used in South Africa as equivalent unit as it is the most important fossil fuel for the country. Crude oil and natural gas resources are currently obtained from reserves elsewhere in the world and characterisation factors are therefore determined using global resources and production levels. The normalisation factors are based on the total economic reserves of key South African minerals and world non-renewable energy resources respectively. A case study of the manufacturing of an exhaust system for a standard sedan is used to compare LCIA results for mined abiotic resource categories that are based on current LCIA factors and the new South African factors. Results and Discussion The South African LCIA procedure differs from current methods in that it shows the importance of other mined resources, i.e. iron ore and crude oil, relative to PGMs and coal for the manufacturing life cycle of the exhaust system. With respect to PGMs, the current characterisation factors are based on the concentrations of the metals in the ores and the ultimate reserves, which are erroneous with respect to the actual availability of the mineral resources and the depletion burden placed on these minerals is consequently too high. Conclusions The South African LCIA procedure for mined abiotic resources depletion shows the significance of choosing a method, which is inline with the current situation in the mining industry and its limitations. Recommendations and Outlook It is proposed to similarly investigate the impacts of the use of other natural resource groups. Water, specifically, must receive attention in the characterisation phase of LCIAs in South African LCAs.     

Assessment of Land Use Impacts on the Natural Environment. Part 1: An Analytical Framework for Pure Land Occupation and Land Use Change (8 pp)

- Part 1: An analytical framework for pure land occupation and land use change Part 2: Generic characterization factors for local species diversity in Central Europe - Preamble. This series of two papers is based on a PhD thesis (Koellner 2003) and develops a method on how to assess land use impacts on biodiversity in the framework of LCA. Part 1 further expands the analytical framework of the thesis for pure land occupation and land use change. Part 2 rests on a much richer database compared to the thesis in order to quantify generic characterization factors for local species' richness. - Abstract Goal, Scope and Background. In the framework of LCA, land use is broadly accepted as an impact category. However, the methodology for the assessment of damages on the natural environment was and still is the subject of discussion. The main objective of this paper is to contribute to that discussion by providing a consistent methodological framework for the assessment of land occupation and transformation. Methods We clarify the context of LCA relevant land use decisions. Based on that, we develop a formal model with damage functions and generic characterization factors for quantifying damages on ecosystems from land occupation and land transformation. The characterization factor for land occupation and land use change is labeled Ecosystem Damage Potential (EDP). We analytically address the substitutability of area and time occupied in order to produce a constant output. Results Based on the proposed method, it is possible to calculate the damages from complex series of land transformation, land occupation, and land restoration. A main feature of the method is that land transformation is assessed based on a factual or virtual, restoration time. This means that the damage of land transformation is largest for land use types which are difficult to restore and need extremely long to develop (e.g. thousand of years and more for primary forest and peatbog). In addition, we could show that area and time of occupation are not substitutable. The more severe the damage potential of a specific land use type is, the better it is to minimize the area and maximize the duration of occupation. Discussion An approach for the assessment of pure land occupation and land use change was developed in this paper, which is not geographically referenced. Developing geographically-referenced land use inventories and impact assessment methods can increase their accuracy. The information cost to provide geographically referenced data on land use for practical LCA applications, however, would increase enormously. Conclusions An impact assessment method for land use with generic characterization factors improves the basis for decision-making in industry and other organizations. It can best be applied to marginal land use decisions; that is, to decisions in which the consequences are so small that the quality or quantity of environmental parameters of a region is not noticeably altered. Recommendations and Perspective . One main problem to address is the development of reliable generic characterization factors, which express the ecosystem damage potential of specific land use types. The characterization factors should be developed on an empirical basis, which allow decision makers to get access to knowledge from environmental sciences in a very condensed form. In order to support decisions on distinct land use projects, methods should be developed, which allow accomplishing a generic assessment with site-dependent assessments.     

A New LCA Methodology of Technology Evolution (TE-LCA) and its Application to the Production of Ammonia (1950-2000) (8 pp)

Goal, Scope and Background

This paper presents a new LCA method of technology evolution (TE-LCA), and its application to the production of ammonia, the second largest chemical product in the world, over the last fifty years. The TE-LCA of a chemical process is the procedure in which historical information on a process, mainly the evolution of technical parameters, is translated by simulation to mass and energy balances as a function of time. These mass and energy balances are then transformed into environmental impact indicators using common LCA approaches. Finally, the evolution of environmental impact resulting from the investigated process can be related to its technical and other, i.e. legislative, developments.

Methods

The technological evolution of the production of ammonia was compiled according to three basic sources of information: patents, publications and industry data. From these sources in a first step, the major technological advances of the process were identified as a function of time delivering different process variants that were modelled using the simulation software Aspen Plus®. In a second step, the evolution of environmental regulations is studied. For those energy related emissions that were regulated, e.g. SOx and NOx, it was assumed that threshold values defined in legislation were realized immediately. The aggregation of both steps allows the calculation of the emissions resulting from the production (cradle to gate view) of the investigated chemical as a function of time.

Results and Discussion

The application of the TE-LCA to the production of ammonia revealed when and to which extent technological and legislative developments resulted in the reduction of energy related emissions in the production of this chemical compound. Overall, the reduction of emissions from ammonia production was highly influenced by the technological development and only to a lower extent by environmental regulations.

Conclusion

The results obtained from the TE-LCA method is useful to reveal how the environmental performance of a process developed in the past and to identify the reasons for this development. The investigated case study of ammonia production shows that investment in technological development also paid off in terms of being ahead of tightened environmental legislation that might bear potential cost consequences such as carbon dioxide tax.

Outlook

The presented method can be easily extended by including an economic analysis, which provides additional information on why certain technological developments were enforced and which the economic consequences of changes in environmental legislation were. The new methodology has to be applied to additional case studies, i.e. to other chemical sectors than basic chemicals and to other branches than chemicals. In other chemical sectors, toxic emissions from the production process might have to be considered and trade-offs between these and the overall energy consumption might result.     

Feasibility of Applying Site-dependent Impact Assessment of Acidification in LCA (8 pp)

Goal, Scope and Background Taking into account the location of emissions and its subsequent, site-dependent impacts improves the accuracy of LCIA. Opponents of site-dependent impact assessment argue that it is too time-consuming to collect the required additional inventory data. In this paper we quantify this time and look into the added value of site-dependent LCIA results. Methods We recalculated the acidifying impact for three existing LCA studies: linoleum, stone wool, and water piping systems. The amount of time needed to collect the required additional data is reported. The EDIP2003 methodology provides site-generic and site-dependent acidification factors. We used these factors to recalculate acidification for the case studies. We analyzed differences between site-generic and site-dependent acidification and reported problems experienced. Results and Discussion Finding the location of processes and emissions was easy. The reports of the three case studies contained most of this information. Far more time was needed to disaggregate processes to the level where emissions can be localized. Although the overall conclusions with regard to acidification did not change in the case studies, the relative importance of processes shifted when considering sub-levels. This is especially important for improvement analysis. Site-dependent acidification assessment was hampered in the linoleum case study where about 40% of the acidification originates from non-European emissions. However, EDIP2003 provides no site-dependent factors for these countries and site-generic factors had to be used instead. Thus, calculating site-dependent acidification is only feasible for LCA studies in which the majority of the emissions originate in Europe. We could not reproduce all parts of the three case studies using the report and additional public resources. This hindered our recalculation. In fact, any additional analysis will be hampered by this lack of reproducibility. ISO recommends such reproducibility for comparative assertion disclosed to the public. Conclusion Spatially differentiated acidification is feasible for each of the three case studies. Finding the location of processes and emissions was easy, but quite some time was needed to disaggregate processes and emissions to the appropriate level. Overall conclusions on acidification remained the same for the case studies, but the relative contribution of basic processes changed when applying site-dependent impact assessment. Though the three case studies were all rather detailed and complete, none of them was fully reproducible. This complicated recalculation of acidification, and will in fact make any additional analysis difficult.     

Distance-to-Target Weighting in Life Cycle Impact Assessment Based on Chinese Environmental Policy for the Period 1995-2005 (6 pp)

Background and Objective

. Values in the known weighting methods in Life Cycle Assessment are mostly founded by the societal systems of developed countries. What source of weights and which weighting methods are reliable for a big developing country like China? The purpose of this paper is to find a possible weighting method and available data that will work well for LCA practices conducted in China. Since government policies and decisions play a leading role in the process of environmental protection in developing countries, the weights derived from political statements may be a consensus by representatives of the public.

Methods

'Distance-to-political target' principle is used in this paper to derive weights of five problem-oriented impact categories. The critical policy targets are deduced from the environmental policies issued in the period of the Ninth Five-year (1996-2000) and the Tenth Five-year (2001-2005) Plan for the Development of National Economy and Society of China. Policy targets on two five-year periods are presented and analyzed. Weights are determined by the quotient between the reference levels and target levels of a certain impact category.

Results and Discussion

Since the Tenth Five-year Plan put forward the overall objective to reduce the level of regional pollution by 2005, the weights for AP, EP and POCP for 2000-2005 are more than 1. By comparison between the Ninth Five-year and Tenth Five-year period, the results show that the weights obtained in this paper effectively represent Chinese political environmental priorities in different periods. For the weights derived from China's political targets for the overall period 1995-2005, the rank order of relative importance is ODP>AP>POCP>EP>GWP. They are recommended to the potential users for the broader disparity among the five categories. By comparison with the weights presented by the widespread EDIP method, the result shows that there's a big difference in the relative importance of ozone depletion and global warming.

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In conclusion, the weighting factors and rank order of impact categories determined in this study represent the characteristics of the big developing country. The derived weighting set can be helpful to LCA practices of products within the industrial systems of China.

     

Ecological Toxicity Methods and Metals. An examination of two case studies (8 pp + 1)

Goal, Scope and Background The Apeldoorn Workshop (April 15th, 2004, Apeldoorn, NL) brought together specialists in LCA and Risk Assessment to discuss current practices and complications of the life cycle impact assessment (LCIA) ecological toxicity (ecotox) methodologies for metals. The consensus was that the LCIA methods currently available do not appropriately characterize impacts of metals due to lack of fundamental metals chemistry in the models. A review of five methods available to perform ecotox impact assessment for metals has been prepared to provide Life Cycle Assessment (LCA) practitioners with a better understanding of the current state of the science and potential biases related to metals. The intent is to provide awareness on issues related to ecotox impact assessment. Methods In this paper two case studies, one a copper based product (copper tube), the other a zinc-based product (gutter systems), were selected and examined by applying freshwater ecological toxicity impact models – USES-LCA, Eco-indicator 99 (EI 99), IMPACT 2002, EDIP 97, and CalTOX-ETP. Both studies are recent, comprehensive, cradle-to-gate, and peer-reviewed. The objective is to review the LCIA results in the context of the practical concerns identified by the Apeldoorn Declaration, in particular illustrating any inconsistencies such as chemical characterization coverage, species specificity, and relative contribution to impact results. Results and Discussion The results obtained from all five of the LCIA methods for the copper tube LCI pointed to the same substance as being the most important – copper. This result was obtained despite major fundamental differences between the LCIA methods applied. However, variations of results were found when examining the freshwater ecological toxicity potential of zinc gutter systems. Procedural difficulties and inconsistencies were observed. In part this was due to basic differences in model nomenclature and differences in coverage (IMPACT 2002+ and EDIP 97 contained characterization factors for aluminium that resulted in 90% and 22% contribution to burden respectively, the other three methods did not). Differences were also observed relative to the emissions source compartment. In the case of zinc, air emissions were found to be substantial for some ecotox models, whereas, water emissions results were found to be of issue for others. Conclusions This investigation illustrates the need to proceed with caution when applying LCIA ecotox methodologies to life cycle studies that include metals. Until further improvements are made, the deficiencies should be clearly communicated as part of LCIA reporting. Business or policy decisions should not without further discussion be based solely on the results of the currently available methods for assessing ecotoxicity in LCIA. Outlook The outlook to remedy deficiencies in the ecological toxicity methods is promising. Recently, the LCIA Toxic Impacts Task Force of the UNEP/SETAC Life Cycle Initiative has formed a subgroup to address specific issues and guide the work towards establishment of sound characterization factors for metals. Although some measure of precision of estimation of potential impact has been observed, such as in the case of copper, accuracy is also a major concern and should be addressed. Further investigation through controlled experimentation is needed, particularly LCIs composed of a variety of inorganics as well as organics constituents. Support for this activity has come from the scientific community and industry as well. Broader aspects of structure and nomenclature are being collectively addressed by the UNEP/SETAC Life Cycle Initiative. These efforts will bring practical solutions to issues of naming conventions and LCI to LCIA flow assignments.     

A Hybrid Approach for Assessing the Multi‐Scale Impacts of Urban Resource Use: Transportation in Phoenix,Arizona

Life cycle assessment (LCA) and urban metabolism (UM) are popular approaches for urban system environmental assessment. However, both approaches have challenges when used across spatial scales. LCA tends to decompose systemic information into micro‐level functional units that mask complexity and purpose, whereas UM typically equates aggregated material and energy flows with impacts and is not ideal for revealing the mechanisms or alternatives available to reduce systemic environmental risks. This study explores the value of integrating UM with LCA, using vehicle transportation in the Phoenix metropolitan area as an illustrative case study. Where other studies have focused on the use of LCA providing upstream supply‐chain impacts for UM, we assert that the broader value of the integrated approach is in (1) the ability to cross scales (from micro to macro) in environmental assessment and (2) establishing an analysis that captures function and complexity in urban systems. The results for Phoenix show the complexity in resource supply chains and critical infrastructure services, how impacts accrue well beyond geopolitical boundaries where activities occur, and potential system vulnerabilities.     

Environmental Impacts of Wild Caught Cod and Farmed Salmon - A Comparison with Chicken (7 pp)

Goal, Scope and Background The objective of this study was to assess environmental impacts of Norwegian cod fishing and salmon farming and compare these with chicken farming in order to find reference levels for environmental performance and identify problem areas and potentials for improvements. Methods A Life Cycle Screening following the production of 0.2 kg fillets as a functional unit through the respective food chains is performed for all 3 products. The analysis is partly quantitative and qualitative focusing on energy use, antifouling and land use impacts. Case studies are performed to investigate potentials for improvements within the fisheries and aquaculture industry. Results and Conclusions It can be concluded that the fishing phase for the cod and the feeding phase for both salmon and chicken dominate for all environmental impacts considered. Chicken is most energy effective followed by salmon and cod, which are almost on the same level. The area of sea floor affected by bottom trawling is around 100 times larger than the land area needed to produce the chicken feed for production of the 0.2 kg fillet. - The case studies show potentials for improvement of environmental performance, both for salmon farming and cod fishing, especially when it comes to energy use. The environmental impacts on the sea floor imposed by bottom trawling are not fully explored, but based on the precautionary principle a reasonable conclusion is that bottom trawls with less impact on the sea floor should be developed. Recommendation and Perspective LCA methods have initially been developed for land based industrial applications. More effort should be given to adapt these to fishing applications in order to obtain more accurate assessment of environmental impacts from seafood products. It is recommended to put more emphasis in finding improved indicators for impacts imposed by over-fishing, fuel emission from combustion at sea, use of antifouling and seafloor ecosystem disturbance.     

A Method for Technology Selection Considering Environmental and Socio-Economic Impacts (11 pp)

Goal, Scope, and Background In Japan, the abatement of CO2 emission by households is a significant problem. Hence, it is necessary to formulate a long-term policy on the use of long-life and highly-insulating technologies for houses; these technologies are expected to reduce CO2 emission. The conventional LCA methodology can evaluate the environmental impact of these technologies, while not necessarily providing sufficient information to support policy-making because of its analytical perspective. The aim of the present study is to first develop a new methodology to examine the optimal use of technologies to formulate an environmental policy by considering dynamic socio-economic conditions. Second, as a demonstration, such a developed methodology is applied to explore an environmentally conscious housing policy for CO2 abatement in Japan. Methods A new methodology was developed, considering the context of a society where technologies are introduced, in order to determine the optimal configuration of technologies to minimize the cumulative environmental burden over time on a social scale. An inter-temporal linear programming model using an input-output table was formulated to make the methodology operational. Using the new model, the optimal use of long-life and thermal-insulating technologies for houses is examined to minimize CO2 emissions across the entire life cycle of all the houses in Japan. Results and Discussion The results of the model simulation indicate that not only long-life and highly-insulating technologies, but also short-life and poorly-insulating technologies, are required to minimize CO2 emissions over a long period. According to the conventional LCA, a house with a short life is inferior to that with a long life, and a house with poor insulation is inferior to that with high insulation. However, houses with a short life and/or poor insulation are introduced in a transition phase to a certain extent before the final stage is reached that is completely dominated by highly-insulated houses with a long life. In other words, the existing houses that were built in the past are gradually replaced with highly-insulated houses with a long life after first building houses with a short life and/or poor insulation. It is not always feasible or not necessarily an optimal solution on a social scale to introduce only a technology that is best evaluated by using the conventional LCA. Inferior technologies can also play a significant role because of various socio-economic conditions and requirements, e.g. population decline, limited housing budgets, and employment stability. Dynamic socio-economic conditions significantly influence the optimal mix of technologies for CO2 minimization in the entire society. Conclusion and Recommendation The present study suggests that it is critical to consider dynamic socio-economic conditions when examining technologies for selection with the aim of a long-term reduction of the environmental burden. The new methodology proposed can provide valuable information to support policy-making toward a sustainable society.     

LCA of Ex-Situ Bioremediation of Diesel-Contaminated Soil (11 pp)

- DOI: http://dx.doi.org/10.1065/lca2004.09.180.12 Goal and Scope Primary and secondary environmental impacts associated with bioremediation of diesel-contaminated sites were assessed using a retrospective life cycle assessment (LCA) as a function of the duration of treatment and the achievement of regulatory criteria. The case study was the remediation with biopiles of 8000 m3 of subsurface soil impacted with an average of 6145 mg of diesel fuel/kg soil during a two-year period. Methods Two scenarios were compared; the construction of a single-use treatment facility on site or the use of a permanent treatment center that can accept 25000 m3 soil/year. Moreover, since bioremediation is never 100% efficient, different efficiency scenarios, including the transportation of partially treated soil to landfill were analyzed. The primary impact of residual soil contamination was determined by developing a specific characterization factor (ecotoxicity and human toxicity categories in the EDIP method) based on the toxic components of diesel. Secondary impacts were assessed with an LCA software. Results and Discussion One major observation was the fact that the soil itself is responsible for an important fraction of the system's total impact, suggesting that it is beneficial to reach the highest level of remediation. The reutilization of the treatment facility is also an important issue in the overall environmental performance of the system. In the case of a single-use treatment center, the analysis showed that site preparation and site closure were the major contributing stages to the overall impact, mainly due to the asphalt paving and landfilling processes. Results indicated that off-site transport and the biotreatment process did not contribute notably to the level of environmental impact. The use of a permanent treatment center is preferred since it allows a significant decrease of the secondary impact. However, when soil had to be transported for a distance greater than 200 km from the site, global impacts increased significantly. Conclusion – Results from this study allowed identifying several process optimizations in order to improve the environmental performance of the biopile technology including: the achievement of low level of residual contaminants, the minimization of asphalt or the use of a permanent treatment center. Recommendation and Outlook LCA was found to be an efficient tool to manage contaminated soil in a sustainable way. However, because of the major contribution of residual soil contamination, additional spatial and temporal data should be collected and integrated in the substance characterization models.     

Evaluation of Ecotoxicity Effect Indicators for Use in LCIA (10+4 pp)

Goal, Scope and Background The paper describes different ecotoxicity effect indicator methods/approaches. The approaches cover three main groups, viz. PNEC approaches, PAF approaches and damage approaches. Ecotoxicity effect indicators used in life cycle impact assessment (LCIA) are typically modelled to the level of impact, indicating the potential impact on 'ecosystem health'. The few existing indicators, which are modelled all the way to damage, are poorly developed, and even though relevant alternatives from risk assessment exist (e.g. recovery time and mean extinction time), these are unfortunately at a very early stage of development, and only few attempts have been made to include them in LCIA. Methods The approaches are described and evaluated against a set of assessment criteria comprising compatibility with the methodological requirements of LCIA, environmental relevance, reproducibility, data demand, data availability, quantification of uncertainty, transparency and spatial differentiation. Results and Discussion The results of the evaluation of the two impact approaches (i.e. PNEC and PAF) show both pros and cons for each of them. The assessment factor-based PNEC approaches have a low data demand and use only the lowest data (e.g. lowest NOEC value). Because it is developed in tiered risk assessment, and hence makes use of conservative assessment factors, it is not optimal, in its present form, to use in the comparative framework of LCIA, where best estimates are sought. The PAF approaches have a higher data demand but use all data and can be based on effect data (PNEC is no-effect-based), thus making these approaches non-conservative and more suitable for LCIA. However, indiscriminate use of ecotoxicity data tends to make the PAF-approaches no more environmentally relevant than the assessment factor-based PNEC approaches. The PAF approaches, however, can at least in theory be linked to damage modelling. All the approaches for damage modelling which are included here have a high environmental relevance but very low data availability, apart from the 'media recovery-approach', which depends directly on the fate model. They are all at a very early stage of development. Conclusion Recommendations and Outlook. An analysis of the different PAF approaches shows that the crucial point is according to which principles and based on which data the hazardous concentration to 50% of the included species (i.e. HC50) is estimated. The ability to calculate many characterisation factors for ecotoxicity is important for this impact category to be included in LCIA in a proper way. However, the access to effect data for the relevant chemicals is typically limited. So, besides the coupling to damage modelling, the main challenge within the further development and improvement of ecotoxicity effect indicators is to find an optimal method to estimate HC50 based on little data.     

Life Cycle Assessment of Water: From the pumping station to the wastewater treatment plant (9 pp)

Goal, Scope and Background The goal of this study is to determine the environmental impact of using one cubic metre of water in the Walloon Region. The whole anthropogenic water cycle is analysed, from the pumping stations to the wastewater treatment plants. The functional unit has been defined as one cubic metre of water at the consumer tap. This study was carried out in the context of the EU Water Framework Directive. It is part of a programme called PIRENE launched by the Walloon Region to fulfil the requirements of this Directive. Methods A model of the whole anthropogenic water cycle in the Walloon Region was developed. The model is mainly based on site-specific data given by the companies working in the field of water production and wastewater treatment. It was used to assess the environmental impact from the pumping station to the wastewater treatment plant using the Eco-Indicator 99 methodology. Eco-Indicator 99 has been adapted in order to better take into account environmental impact of acidification and eutrophication. Characterisation factors have been calculated for COD, nitrogen and phosphate emissions. From the reference model, different scenarios have been elaborated. Results and Discussion On the basis of the inventory, the environmental impact of five scenarios has been evaluated. Acidification and eutrophication is the most important impact category. It is mainly caused by the wastewater that is discharged without any treatment, but also by the effluent of the wastewater treatment plant. So, this impact category has the lowest environmental load when the wastewater treatment rate is high. For the other impact categories, the impact generally increases with the wastewater treatment rate. During wastewater treatment, energy and chemicals are indeed consumed to improve the quality of the final outputs, and thus to reduce the environmental impact related to acidification and eutrophication. A comparison between the scenarios has also shown that the building of the sewer network has a significant contribution to the global environmental load and that the stages before the tap contribute less to the environmental impact than the stage after the tap. Conclusions The three stages that contribute significantly to the global environmental load are: water discharge, wastewater treatment operation and, to a lesser extent, the sewer system. The results show that the wastewater treatment rate must be as high as possible, using either collective or individual wastewater treatment plants. Even a small water discharge without any treatment has a significant environmental impact. Operation of the wastewater treatment plants must also be improved to reduce the environmental impact caused by the effluent of the plants. For new wastewater treatment plants, building plants treating nitrogen and phosphorus should be encouraged. A sensitivity analysis was conducted and showed that the results of the study were not very affected by a modification of key parameters. Impact assessment using the CML methodology has confirmed the results obtained with Eco-Indicator 99.     

Attributional and Consequential Environmental Assessment of the Shift to Lead-Free Solders (10 pp)

- Goal, Scope, Background. As of July 1st, 2006, lead will be banned in most solder pastes used in the electronics industry. This has called for environmental evaluation of alternatives to tin-lead solders. Our life cycle assessment (LCA) has two aims: (i) to compare attributional and consequential LCA methodologies, and (ii) to compare a SnPb solder (62% tin, 36% lead, 2% silver) to a Pb-free solder (95.5% tin, 3.8% silver, 0.7% copper). Methods An attributional LCA model describes the environmental impact of the solder life cycle. Ideally, it should include average data on each unit process within the life cycle. The model does not include unit processes other than those of the life cycle investigated, but significant cut-offs within the life cycle can be avoided through the use of environmentally expanded input-output tables. A consequential LCA model includes unit processes that are significantly affected irrespective of whether they are within or outside the life cycle. Ideally, it should include marginal data on bulk production processes in the background system. Our consequential LCA model includes economic partial equilibrium models of the lead and scrap lead markets. However, both our LCA models are based on data from the literature or from individual production sites. The partial equilibrium models are based on assumptions. The life cycle impact assessment is restricted to global warming potential (GWP). Results and Discussion The attributional LCA demonstrates the obvious fact that the shift from SnPb to Pb-free solder means that lead is more or less eliminated from the solder life cycle. The attributional LCA results also indicate that the Pb-free option contributes 10% more to the GWP than SnPb. Despite the poor quality of the data, the consequential LCA demonstrates that, when lead use is eliminated from the solder life cycle, the effect is partly offset by increased lead use in batteries and other products. This shift can contribute to environmental improvement because lead emissions are likely to be greatly reduced, while batteries can contribute to reducing GWP, thereby offsetting part of the GWP increase in the solder life cycle. Conclusions The shift from SnPb to Pb-free solder is likely to result in reduced lead emissions and increased GWP. Attributional and consequential LCAs yield complementary knowledge on the consequences of this shift in solder pastes. At present, consequential LCA is hampered by the lack of readily available marginal data and the lack of input data to economic partial equilibrium models. However, when the input to a consequential LCA model is in the form of quantitative assumptions based on a semi-qualitative discussion, the model can still generate new knowledge. Recommendations and Outlook Experts on partial equilibrium models should be involved in consequential LCA modeling in order to improve the input data on price elasticity, marginal production, and marginal consumption.     

A Risk-Based Approach to Health Impact Assessment for Input-Output Analysis, Part 2: Case Study of Insulation (8 pp)

Goal, Scope and Background In the first part of this paper, we developed a methodology to incorporate exposure and risk concepts into life cycle impact assessment (LCIA). We argued that both risk assessment and LCIA are needed to consider the impacts of increasing insulation for single-family homes in the US from current practice to the levels recommended by the 2000 International Energy Conservation Codes. In this analysis, we apply our model to the insulation case study and evaluate the benefits and costs of increased insulation for new housing. Results and Discussion The central estimate of impacts from the complete insulation manufacturing supply chain is approximately 14 premature deaths, 400 asthma attacks, and 7000 restricted activity days nationwide for one year of increased fiberglass output. Of the health impacts associated with increased insulation manufacturing, 83% is attributable to the supply chain emissions from the mineral wool industry, which is mostly associated with the direct primary PM2.5 emissions from the industry (98%). Reduced energy consumption leads to 1.2 premature deaths, 33 asthma attacks, and 600 restricted activity days avoided per year, indicating a public health “payback period” on the order of 11 years. Over 90% of these benefits were associated with direct emissions from power plants and residential combustion sources. In total, the net present value of economic benefits over a 50-year period for a single-year cohort of new homes is $190 million with a 5% discount rate, with 49 fewer premature deaths in this period. Conclusion Recommendation and Outlook. We have developed and applied a risk-based model to quantify the public health costs and benefits of increased insulation in new single-family homes in the US, demonstrating positive net economic and public health benefits within the lifetimes of the homes. More broadly, we demonstrated that it is feasible to incorporate exposure and risk concepts into I-O LCA, relying on regression-based intake fractions followed by more refined dispersion modeling. The refinement step is recommended especially if primary PM2.5 is an important source of exposure and if stack heights are relatively low. Where secondary PM2.5 is more important, use of regression-based intake fractions would be sufficient for a reasonable risk approximation. Uncertainties in our risk-based model should be carefully considered; nevertheless, our study can help decision-makers evaluate the costs and benefits of demand-side management policy options from a combined public health and life cycle perspective.