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Increased water scarcity is driving water utilities to consider alternative water supply options (WSOs). Identifying the most sustainable WSOs that meet environmental, economic, and social objectives is challenging due to the overwhelming number of both assessment criteria and treatment configurations, including a growing number of potable reuse options. Conventional approaches using process-based life cycle assessments are data-intensive and site-specific, and therefore not suitable for the early stages of assessing WSOs. To address this gap, we have combined hybrid multi-regional input-output-based life cycle assessment (MRIO-LCA), social impact analysis, and multi-criteria decision analysis (MCDA) to develop a novel, flexible framework with unit process level resolution for the comprehensive evaluation of WSOs. Here we describe the formulation of the framework along with an application to two US utilities considering alternative WSOs. In both cases, given sufficient levels of community acceptance and optimum system design, the results favoured potable reuse WSOs due to their climatic resilience, cost effectiveness and lower environmental impacts (compared to other non-conventional options such as desalination). The generalised and globally applicable framework developed for this study can be used to assess sustainability trade-offs between diverse WSO configurations, providing valuable insights for decision-making processes at the early planning stage, as a complement to existing urban water supply scenario and optimisation models.

© 2018 This study examined the occurrence of 49 micropollutants in reclaimed water and Silver Perch (Bidyanus bidyanus) living in a reclaimed water reservoir. The numbers of micropollutants detected in reclaimed water, Silver Perch liver, and Silver Perch flesh were 20, 23, and 19, respectively. Concentrations of all micropollutants in reclaimed water, except benzotriazole, were well below the Australian Guideline for Recycled Water (AGRW) values for potable purposes. The concentration of benzotriazole in reclaimed water was 675 ± 130 ng/L while the AGRW value for this compound was 7 ng/L. Not all micropollutants detected in the water phase were identified in the Silver Perch flesh and liver tissues. Likewise, not all micropollutants detected in the Silver Perch flesh and liver were identified in the reclaimed water. In general, micropollutant concentrations in the liver were higher than in the flesh. Perfluorooctane sulfonate (PFOS) was detected at a trace level in reclaimed water well below the AGRW guideline value for potable purposes, but showed a high and medium bioconcentration factor in Silver Perch liver and flesh, respectively. In addition, the risk quotient for PFOS was medium and high when considering its concentration in Silver Perch liver and flesh, respectively. Results reported here highlight the need to evaluate multiple parameters for a comprehensive risk assessment. The results also single out PFOS as a notable contaminant of concern for further investigation.

The occurrence of five organophosphate flame retardants (PFRs) consisting of tributyl phosphate (TNBP), tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCIPP), tris(1.3-dichloro-2-propyl) phosphate (TDCIPP) and triphenyl phosphate (TPHP) in swimming pools were investigated. Fifteen chlorinated public swimming pools were sampled, including indoor pools, outdoor pools and spa pools. The analyses were carried out using isotope dilution gas chromatography tandem mass spectrometry. All five PFRs were detected in swimming pool waters with concentrations ranging from 5-27ng/L (TNBP), 7-293ng/L (TCEP), 62-1180ng/L (TCIPP), 10-670ng/L (TDCIPP) and 8-132ng/L (TPHP). The concentrations of PFRs were generally higher in indoor swimming pools compared to outdoor swimming pools. In municipal water supplies, used to fill the swimming pools in three of the sampling locations, the five PFRs were all below the limit of quantifications, eliminating this as the source. Potential leaching of PFRs from commonly used swimming equipment, including newly purchased kickboards and swimsuits was investigated. These experiments revealed that PFRs leached from swimsuits, and may be a source of PFRs in swimming pools. A quantitative risk assessment revealed that the health risk to PFRs via swimming pools was generally low and below commonly applied health risk benchmarks.

Refereed/Peer-reviewed Trace organic chemical (TrOC) contaminants are of concern for finished water from water recycling schemes because of their potential adverse environmental and public health effects. Understanding the impacts of seasonal variations on fate and removal of TrOCs is important for proper operation, risk assessment and management of treatment systems for water recycling such as membrane bioreactors (MBRs). Accordingly, this study investigated the fate and removal of a wide range of TrOCs through a full-scale MBR plant during summer and winter seasons. TrOCs included 12 steroidal hormones, 3 xeno-estrogens, 2 pesticides and 23 pharmaceuticals and personal care products. Seasonal differences in the mechanisms responsible for removing some of the TrOCs were evident. In particular the contribution of biotransformation and biomass adsorption to the overall removal of estrone, bisphenol A, 1713-estradiol and triclosan were consistently different between the two seasons. Substantially higher percentage removal via biotransformation was observed during the summer sampling peiiod, which compensated for a reduction in removal attributed to biomass adsorption. The opposite was observed during winter, where the contribution of biotransformation to the overall removal of these TrOCs had decreased, which was offset by an improvement in biomass adsorption. The exact mechanisms responsible for this shift are unknown, however are likely to be temperature related as warmer temperatures can lower sorption efficiency, yet enhance biotransformation of these TrOCs. (C) 2015 Elsevier B.V. All rights reserved. usc

The occurrence and fate of emerging contaminants (ECs) in surface water bodies is of increasing interest to water quality managers and environmental regulators throughout the world. Wastewater treatment plants are a major source of ECs in many aquatic environments. A modified Quantitative Water Air Sediment Interaction (QWASI) fugacity model was developed for a municipal wastewater lagoon system to study the behaviour of six representative ECs. As the wastewater lagoons were exposed to extensive periods of sunlight, the original model was modified by the addition of photolytic degradation as a removal mechanism. Laboratory studies were conducted over different seasons of a year to obtain the rate constants for the key processes of sunlight photodegradation, water and sediment transformation, as well as sediment sorption coefficients for the target ECs in the system to serve as model inputs. The model predicted the pathways for the different ECs and that at least 65% of the concentration of the ECs remained in the outflow of the first lagoon of the lagoon system after treatment. The greatest removal was predicted for sulfamethoxazole (35%) and the least for carbamazepine (5%). Multi-segment theory was applied to the single lagoon model and the predictions for the sequential six lagoon system were validated through field sampling. Sensitivity analysis revealed that the mass transfer coefficient between the water and sediment phases was the most influential parameter, with the four key process rate constants having various impacts depending on the EC. These results suggest that the modified QWASI model could be used to more accurately represent the fate and transport of ECs in this unique wastewater lagoon/stabilisation pond treatment system. Furthermore, it can be adapted to model a wide range of ECs in other wastewater treatment lagoon systems and thus assist with process optimisation and risk assessment of the treated water.

Disability adjusted life years (DALYs) have been used to quantify endpoint indicators of the human burden of disease in life cycle assessment (LCA). The purpose of this paper was to examine the current use of DALYs in LCA, and also to consider whether DALYs as used in LCA have the potential to be compatible with DALYs as used in quantitative risk assessment (QRA) to facilitate direct comparison of the results of the two approaches. A literature review of current usage of DALYs in LCA was undertaken. Two prominent methods were identified: ReCiPe 2008 and LIME2. The methods and assumptions used in their calculations were then critically reviewed. The assumptions used for the derivation of characterization factors in DALYs were found to be considerably different between LCA methods. In many cases, transparency of these calculations and assumptions is lacking. Furthermore, global average DALY values are often used in these calculations, but may not be applicable for impact categories where the local factors play a significant role. The concept of DALYs seems beneficial since it enables direct comparison and aggregation of different health impacts. However, given the different assumptions used in each LCA method, it is important that LCA practitioners are aware of the differences and select the appropriate method for the focus of their study. When applying DALYs as a common metric between LCA and QRA, understanding the background information on how DALYs were derived is crucial to ensure the consistency of DALYs used in LCA and QRA for resulting DALYs to be comparable and to minimize any double counting of effects.