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Urban water systems in industrialized countries have underpinned unprecedented improvements in urban living standards through effective drinking water supply, sanitation and drainage. However, conventional urban water systems are increasingly regarded as too rigid and not sufficiently resilient to confront growing social, technological and environmental complexity and uncertainty, manifested, for example, in the maladaptation to climate change, depletion of nonrenewable resources, and degrading urban livability. In response, a new urban water paradigm has emerged in the last two decades within the context of a broader societal change that promotes a more organic worldview over the classical mechanistic and technocratic understanding of reality. This article develops and applies an analytical framework to coherently describe the new paradigm and contrast it with the old urban water paradigm. The framework includes a philosophical foundation and set of methodological principles that shape the new paradigm's approach to governance, management, and infrastructure. [ABSTRACT FROM AUTHOR]

Purpose: Many municipalities are facing increasing pressure to adapt solid waste and wastewater management infrastructures in order to better close nutrient cycles. The focus of this study is on the estimation of the human toxicity potential associated with chemical contaminants released upon the application of sewage sludge to agricultural land. More specifically, this study investigated the effect of modelling choices regarding fate and exposure assessment. Methods: Monitoring data were collected for contaminants present in the sewage sludge from the wastewater treatment plant in Gothenburg and from other municipal wastewater treatment plants in Sweden. Based on these monitoring data, an overall burden of disease was estimated using characterisation factors taken from the USEtox models (versions 1.01 and 2.0). For the exposure through vegetables, an alternative life cycle impact assessment (LCIA) model was developed. The intake fractions thus obtained were used in combination with human health effect factors taken from the USEtox 2.0 database. The model results were compared with the USEtox models, and whether these two versions of the USEtox model provide significantly different results was also examined. The potential relevance of accidental ingestion of sludge was also considered. Results and discussion: The different LCIA models provided burden of disease estimates that differed from one another for individual contaminants (up to five orders of magnitude). The aggregated burdens of disease (i.e. sum for all contaminants considered in this study) estimated through different model variants, however, were of the same order of magnitude. For both metals and organic contaminants, only a small set of contaminants was found to make significant contributions to the aggregate burden of disease. However, it is uncertain whether the 15 metals and 106 organic contaminants covered by this study are those of greatest health significance of all contaminants potentially present in sewage sludge. Conclusions and recommendations: The results of this study indicate that the technical information provided by the various approaches to modelling human toxicity in life cycle assessment (LCA) in the context of land application of sewage sludge management is consistent on the whole. However, given the uncertainties associated with the assessment of human toxicity in LCA, it is important to also contemplate the extent to which LCA in general is capable of informing the sewage sludge debate when it comes to human toxicity and possibly also other indicators. Future research could focus on identifying which types of questions of interest in the context of sewage management can be answered by LCA and which cannot. [ABSTRACT FROM AUTHOR]

Household metabolism is a concept that is concerned with the analysis of stocks and flows of energy, matter, and information at the household scale. This paper starts by providing a brief overview of the concept of household metabolism. Rather than attempting an in-depth review and analysis of this field, the article subsequently maps the contributions and perspectives of a broad variety of research traditions that have an interface with the concept of household metabolism. Next, this paper highlights a number of controversial issues connected to household metabolism, and studies at the interface of household metabolism. Finally, this paper argues that the concept of household metabolism can provide valuable help in diagnosing misalignments between enacted system dynamics and expressed societal goals, and can help to design research that facilitates their alignment. [ABSTRACT FROM AUTHOR]

The authors argue in favor of the utility of the functional unit for a life cycle assessment (LCA) study that includes a quantitative microbial risk assessment (QMRA)-based impact category. They believe that an LCA study could be performed in order to identify the wastewater management option with the best environmental performance. The use of QMRA to capture the natural variation in pathogen exposure is cited.