Scientists expect an increase in heavy rainfalls in Switzerland in the future because of climate ... more Scientists expect an increase in heavy rainfalls in Switzerland in the future because of climate change. During heavy rainfall, the wastewater system might not be able to cope with all the rain-water anymore, leading to surcharges of wastewater in combined sewer systems. Untreated wastewater can therefore reach surface waters, which is known as combined sewer overflows (CSOs). Wastewater can also overflow from manholes or sewers, thus flooding streets or cellars. With climate change, these events are expected to occur more often. It is possible to improve the wastewater system with structural measures to cope with such events, but the costs are high. Ultimately, this would result in an increase of the wastewater taxes paid by the population.The aim of our study was to elicit the willingness to pay of the Swiss population for improving the wastewater system in the context of climate change. We implemented an online survey repre\uacsentative of the Swiss population and interviewed 1\u...
Household-centered technologies such as urine source separation (NoMix technology) could induce a... more Household-centered technologies such as urine source separation (NoMix technology) could induce a paradigm change in urban wastewater management, hereby improving water pollution control and resource management. Technological innovations need real-world application for further development. The Swiss research project Novaquatis accompanied five pilot projects from 1997 on. We give a systematic overview of our experience, summarizing various important aspects, a fundamental one being a clearly defined goal. Early stakeholder involvement is crucial, because the still imperfect NoMix technology depends on people's goodwill. We reference data sheets, legal documents, etc. and make suggestions for installation, maintenance, and technology improvement. We identify areas for future research necessitating pilot projects and discuss their requirements to optimize the cost-benefit factor. This paper is intended as support to wastewater professionals to avoid the most serious pitfalls when conducting NoMix pilot projects. It contributes to increased interaction between research and real-world application of urban European household innovations.
... a simplification and does not include various interdependencies between individual factors du... more ... a simplification and does not include various interdependencies between individual factors due to ... For instance, in long-lived species traits affecting survival and fecundity of individuals in a ... the likelihood of self-pollination within flowers and self-pollination among neighbouring ...
Integrative river management involves difficult decisions about alternative measures to improve t... more Integrative river management involves difficult decisions about alternative measures to improve their ecological state. For this reason, it seems useful to apply knowledge from the decision sciences to support river management. We discuss how decision-analytical elements can be employed for designing an integrated river management procedure. An important aspect of this procedure is to clearly separate scientific predictions of the
ABSTRACT We present a novel approach for practically tackling uncertainty in preference elicitati... more ABSTRACT We present a novel approach for practically tackling uncertainty in preference elicitation and predictive modeling to support complex multi-criteria decisions based on multi-attribute utility theory (MAUT). A simplified two-step elicitation procedure consisting of an online survey and face-to-face interviews is followed by an extensive uncertainty analysis. This covers uncertainty of the preference components (marginal value and utility functions, hierarchical aggregation functions, aggregation parameters) and the attribute predictions. Context uncertainties about future socio-economic developments are captured by combining MAUT with scenario planning. We perform a global sensitivity analysis (GSA) to assess the contribution of single uncertain preference parameters to the uncertainty of the ranking of alternatives. This is exemplified for sustainable water infrastructure planning in a case study in Switzerland. We compare 11 water supply alternatives ranging from conventional water supply systems to novel technologies and management schemes regarding 44 objectives. Their performance is assessed for four future scenarios and 10 stakeholders from different backgrounds and decision-making levels. Despite uncertainty in the ranking of alternatives, potential best and worst solutions could be identified. We demonstrate that a priori assumptions such as linear value functions or additive aggregation can result in misleading recommendations, unless thoroughly checked during preference elicitation and modeling. We suggest GSA to focus elicitation on most sensitive preference parameters. Our GSA results indicate that output uncertainty can be considerably reduced by additional elicitation of few parameters, e.g. the overall risk attitude and aggregation functions at higher-level nodes. Here, rough value function elicitation was sufficient, thereby substantially reducing elicitation time.
Water science and technology : a journal of the International Association on Water Pollution Research, 2006
We studied user behavior and acceptance of NoMix toilets by collecting 271 questionnaires from yo... more We studied user behavior and acceptance of NoMix toilets by collecting 271 questionnaires from young adults. We discriminated between short- and long-term users (months of habituation). Most respondents noticed that the NoMix toilet is different. Nevertheless, the existing NoMix technology was well accepted regarding design, hygiene and smell in this institutional setting. Only few respondents changed their sitting or flushing behavior. The necessity to sit when urinating might be slightly problematic (62% sit), but it seems possible that people adopt this new behavior required by the NoMix toilet. General acceptance of the NoMix toilet was high: 70% of respondents found the idea convincing--many for environmental reasons--87% were willing to move into an apartment with a NoMix toilet, and 20% would pay substantially more for a NoMix toilet. We informed about the NoMix toilet with instructions for use in the toilet cabin, an information poster, and an information leaflet that we dis...
Water science and technology : a journal of the International Association on Water Pollution Research, 2003
We studied acceptance of a urine-based fertilizer product using a mail survey of 467 Swiss farmer... more We studied acceptance of a urine-based fertilizer product using a mail survey of 467 Swiss farmers. We distinguished among four production types: organic or IP farming, and with or without vegetable production. Considering that the idea of urine-based fertilizers is new, acceptance among the answering farmers was surprisingly high, with 57% explicitly stating that they thought it was a good or very good idea, and 42% willing to purchase such a product. The farmers of different production types did not differ strongly in their attitude towards urine-based fertilizers. Especially IP and vegetable farmers, who purchased additional fertilizers anyway, seem willing to accept urine-based fertilizers, hereby preferring a grainy, odorless ammonium nitrate fertilizer. Absolutely essential is a hazard-free product: 30% of all farmers had concerns regarding micropollutants. Based on fertilizer data, we demonstrate an existing demand for the nutrients N, P, and K in Switzerland, which could be ...
In this paper, we evaluated the ecotoxicological potential of the 100 pharmaceuticals expected to... more In this paper, we evaluated the ecotoxicological potential of the 100 pharmaceuticals expected to occur in highest quantities in the wastewater of a general hospital and a psychiatric center in Switzerland. We related the toxicity data to predicted concentrations in different wastewater streams to assess the overall risk potential for different scenarios, including conventional biological pretreatment in the hospital and urine source separation. The concentrations in wastewater were estimated with pharmaceutical usage information provided by the hospitals and literature data on human excretion into feces and urine. Environmental concentrations in the effluents of the exposure scenarios were predicted by estimating dilution in sewers and with literature data on elimination during wastewater treatment. Effect assessment was performed using quantitative structure-activity relationships because experimental ecotoxicity data were only available for less than 20% of the 100 pharmaceuticals with expected highest loads. As many pharmaceuticals are acids or bases, a correction for the speciation was implemented in the toxicity prediction model. The lists of Top-100 pharmaceuticals were distinctly different between the two hospital types with only 37 pharmaceuticals overlapping in both datasets. 31 Pharmaceuticals in the general hospital and 42 pharmaceuticals in the psychiatric center had a risk quotient above 0.01 and thus contributed to the mixture risk quotient. However, together they constituted only 14% (hospital) and 30% (psychiatry) of the load of pharmaceuticals. Hence, medical consumption data alone are insufficient predictors of environmental risk. The risk quotients were dominated by amiodarone, ritonavir, clotrimazole, and diclofenac. Only diclofenac is well researched in ecotoxicology, while amiodarone, ritonavir, and clotrimazole have no or very limited experimental fate or toxicity data available. The presented computational analysis thus helps setting priorities for further testing. Separate treatment of hospital wastewater would reduce the pharmaceutical load of wastewater treatment plants, and the risk from the newly identified priority pharmaceuticals. However, because high-risk pharmaceuticals are excreted mainly with feces, urine source separation is not a viable option for reducing the risk potential from hospital wastewater, while a sorption step could be beneficial.
Scientists expect an increase in heavy rainfalls in Switzerland in the future because of climate ... more Scientists expect an increase in heavy rainfalls in Switzerland in the future because of climate change. During heavy rainfall, the wastewater system might not be able to cope with all the rain-water anymore, leading to surcharges of wastewater in combined sewer systems. Untreated wastewater can therefore reach surface waters, which is known as combined sewer overflows (CSOs). Wastewater can also overflow from manholes or sewers, thus flooding streets or cellars. With climate change, these events are expected to occur more often. It is possible to improve the wastewater system with structural measures to cope with such events, but the costs are high. Ultimately, this would result in an increase of the wastewater taxes paid by the population.The aim of our study was to elicit the willingness to pay of the Swiss population for improving the wastewater system in the context of climate change. We implemented an online survey repre\uacsentative of the Swiss population and interviewed 1\u...
Household-centered technologies such as urine source separation (NoMix technology) could induce a... more Household-centered technologies such as urine source separation (NoMix technology) could induce a paradigm change in urban wastewater management, hereby improving water pollution control and resource management. Technological innovations need real-world application for further development. The Swiss research project Novaquatis accompanied five pilot projects from 1997 on. We give a systematic overview of our experience, summarizing various important aspects, a fundamental one being a clearly defined goal. Early stakeholder involvement is crucial, because the still imperfect NoMix technology depends on people's goodwill. We reference data sheets, legal documents, etc. and make suggestions for installation, maintenance, and technology improvement. We identify areas for future research necessitating pilot projects and discuss their requirements to optimize the cost-benefit factor. This paper is intended as support to wastewater professionals to avoid the most serious pitfalls when conducting NoMix pilot projects. It contributes to increased interaction between research and real-world application of urban European household innovations.
... a simplification and does not include various interdependencies between individual factors du... more ... a simplification and does not include various interdependencies between individual factors due to ... For instance, in long-lived species traits affecting survival and fecundity of individuals in a ... the likelihood of self-pollination within flowers and self-pollination among neighbouring ...
Integrative river management involves difficult decisions about alternative measures to improve t... more Integrative river management involves difficult decisions about alternative measures to improve their ecological state. For this reason, it seems useful to apply knowledge from the decision sciences to support river management. We discuss how decision-analytical elements can be employed for designing an integrated river management procedure. An important aspect of this procedure is to clearly separate scientific predictions of the
ABSTRACT We present a novel approach for practically tackling uncertainty in preference elicitati... more ABSTRACT We present a novel approach for practically tackling uncertainty in preference elicitation and predictive modeling to support complex multi-criteria decisions based on multi-attribute utility theory (MAUT). A simplified two-step elicitation procedure consisting of an online survey and face-to-face interviews is followed by an extensive uncertainty analysis. This covers uncertainty of the preference components (marginal value and utility functions, hierarchical aggregation functions, aggregation parameters) and the attribute predictions. Context uncertainties about future socio-economic developments are captured by combining MAUT with scenario planning. We perform a global sensitivity analysis (GSA) to assess the contribution of single uncertain preference parameters to the uncertainty of the ranking of alternatives. This is exemplified for sustainable water infrastructure planning in a case study in Switzerland. We compare 11 water supply alternatives ranging from conventional water supply systems to novel technologies and management schemes regarding 44 objectives. Their performance is assessed for four future scenarios and 10 stakeholders from different backgrounds and decision-making levels. Despite uncertainty in the ranking of alternatives, potential best and worst solutions could be identified. We demonstrate that a priori assumptions such as linear value functions or additive aggregation can result in misleading recommendations, unless thoroughly checked during preference elicitation and modeling. We suggest GSA to focus elicitation on most sensitive preference parameters. Our GSA results indicate that output uncertainty can be considerably reduced by additional elicitation of few parameters, e.g. the overall risk attitude and aggregation functions at higher-level nodes. Here, rough value function elicitation was sufficient, thereby substantially reducing elicitation time.
Water science and technology : a journal of the International Association on Water Pollution Research, 2006
We studied user behavior and acceptance of NoMix toilets by collecting 271 questionnaires from yo... more We studied user behavior and acceptance of NoMix toilets by collecting 271 questionnaires from young adults. We discriminated between short- and long-term users (months of habituation). Most respondents noticed that the NoMix toilet is different. Nevertheless, the existing NoMix technology was well accepted regarding design, hygiene and smell in this institutional setting. Only few respondents changed their sitting or flushing behavior. The necessity to sit when urinating might be slightly problematic (62% sit), but it seems possible that people adopt this new behavior required by the NoMix toilet. General acceptance of the NoMix toilet was high: 70% of respondents found the idea convincing--many for environmental reasons--87% were willing to move into an apartment with a NoMix toilet, and 20% would pay substantially more for a NoMix toilet. We informed about the NoMix toilet with instructions for use in the toilet cabin, an information poster, and an information leaflet that we dis...
Water science and technology : a journal of the International Association on Water Pollution Research, 2003
We studied acceptance of a urine-based fertilizer product using a mail survey of 467 Swiss farmer... more We studied acceptance of a urine-based fertilizer product using a mail survey of 467 Swiss farmers. We distinguished among four production types: organic or IP farming, and with or without vegetable production. Considering that the idea of urine-based fertilizers is new, acceptance among the answering farmers was surprisingly high, with 57% explicitly stating that they thought it was a good or very good idea, and 42% willing to purchase such a product. The farmers of different production types did not differ strongly in their attitude towards urine-based fertilizers. Especially IP and vegetable farmers, who purchased additional fertilizers anyway, seem willing to accept urine-based fertilizers, hereby preferring a grainy, odorless ammonium nitrate fertilizer. Absolutely essential is a hazard-free product: 30% of all farmers had concerns regarding micropollutants. Based on fertilizer data, we demonstrate an existing demand for the nutrients N, P, and K in Switzerland, which could be ...
In this paper, we evaluated the ecotoxicological potential of the 100 pharmaceuticals expected to... more In this paper, we evaluated the ecotoxicological potential of the 100 pharmaceuticals expected to occur in highest quantities in the wastewater of a general hospital and a psychiatric center in Switzerland. We related the toxicity data to predicted concentrations in different wastewater streams to assess the overall risk potential for different scenarios, including conventional biological pretreatment in the hospital and urine source separation. The concentrations in wastewater were estimated with pharmaceutical usage information provided by the hospitals and literature data on human excretion into feces and urine. Environmental concentrations in the effluents of the exposure scenarios were predicted by estimating dilution in sewers and with literature data on elimination during wastewater treatment. Effect assessment was performed using quantitative structure-activity relationships because experimental ecotoxicity data were only available for less than 20% of the 100 pharmaceuticals with expected highest loads. As many pharmaceuticals are acids or bases, a correction for the speciation was implemented in the toxicity prediction model. The lists of Top-100 pharmaceuticals were distinctly different between the two hospital types with only 37 pharmaceuticals overlapping in both datasets. 31 Pharmaceuticals in the general hospital and 42 pharmaceuticals in the psychiatric center had a risk quotient above 0.01 and thus contributed to the mixture risk quotient. However, together they constituted only 14% (hospital) and 30% (psychiatry) of the load of pharmaceuticals. Hence, medical consumption data alone are insufficient predictors of environmental risk. The risk quotients were dominated by amiodarone, ritonavir, clotrimazole, and diclofenac. Only diclofenac is well researched in ecotoxicology, while amiodarone, ritonavir, and clotrimazole have no or very limited experimental fate or toxicity data available. The presented computational analysis thus helps setting priorities for further testing. Separate treatment of hospital wastewater would reduce the pharmaceutical load of wastewater treatment plants, and the risk from the newly identified priority pharmaceuticals. However, because high-risk pharmaceuticals are excreted mainly with feces, urine source separation is not a viable option for reducing the risk potential from hospital wastewater, while a sorption step could be beneficial.
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