Hydro-epidemiological modelling of bacterial transport and decay in nearshore coastal waters

In recent years, society has become more aware and concerned with the environmental and human health impacts of population growth and urbanisation. In response, a number of legislative measures have been introduced within Europe (and globally), which have sparked much cross-disciplinary research aimed at predicting and quantifying these impacts, and suggesting mitigation measures. In response to such measures this paper is focused on improving current understanding of, and simulating water quality, in the form of bacterial transport and decay, in the aquatic environment and particularly in macro-tidal environments. A number of 2D and 3D hydro-epidemiological models were developed using the TELEMAC suite to predict faecal bacterial levels for a data rich pilot site, namely Swansea Bay, located in the south west of the UK, where more than 7,000 FIO samples were taken and analysed over a two year period. A comparison of 2D and 3D modelling approaches highlights the importance of accurately representing source momentum terms in hydro-epidemiological models. Improvements in 2D model bacterial concentration predictions were achieved by the application of a novel method for representing beach sources within the nearshore zone of a macro-tidal environment. In addition, the use of a depth-varying decay rate was found to enhance the prediction of Faecal Indicator Organism concentrations in 3D models. Recommendations are made for the use of these novel approaches in future modelling studies

Regulating services

No abstract available

Time for a Nappy Change: controls affecting families’ nappy choices

Lifecycle assessments suggest that modern cloth nappies have fewer environmental impacts than their disposablecounterparts in terms of GHG, plastic and landfill (UNEP 2021). However, despite these apparent environmentalbenefits consumers still use predominantly disposable nappies. This paper will use theories of plannedbehaviour to explore the differences in perceived and actual behaviours between disposable and cloth nappyusers. A self-selecting web-based survey was used to recruit participants with children up to the age of fiveand explore their decision-making in this regard. The findings of the survey reveal that disposable nappy usersare more likely to prioritise convenience and to cite additional laundry loads as the main reasons for not usingcloth nappies. This is despite tending to have the necessary infrastructure (such as disposable income, spaceand washing facilities) to enable them to do so. This indicates that the perceptions of home-laundered clothnappies as inconvenient makes families more likely to opt for disposable nappies. Whilst cloth nappies weregenerally assumed to be more environmentally friendly and aesthetically pleasing by all parents irrespectiveof their choices, this was not enough to overcome the convenience and ease of use for the majority of participants.This study concludes that many disposable nappy users select disposable nappies with the assumptionthat they are easier and more convenient when this may not be the case. The implication of this study is thatinterventions which improve the convenience of cloth nappies and the perception of ease of use will encouragegreater uptake of cloth nappies.References.UNEP. (2021) Recommendations from Life Cycle Assessments Single-use nappies and their alternatives hostedby. United Nations Environment Programme

Impact of Albufeira bay outfall plumes in bathing water quality, a modelling approach

Dissertação de mestrado, Ciclo Urbano da Água, Instituto Superior de Engenharia, Universidade do Algarve, 2017O turismo em zonas balneares é responsável por pressões nas infraestruturas do ciclo urbano da água e recursos hídricos, nomeadamente na conceção de sistemas de abastecimento de água e saneamento. O presente trabalho tem como objetivo avaliar o comportamento hidrodinâmico de três emissários submarinos e impacte na qualidade das águas balneares na baía de Albufeira usando uma abordagem de modelação matemática, com base no software MOHID. São investigados os principais processos que controlam a dispersão na baía. Os primeiros desenvolvimentos consistem numa série de campanhas de medição e colheita de dados (parâmetros microbiológicos, caudais, vento, etc.) que fornecem os dados para caracterizar a dispersão neste sistema costeiro. Uma rede de pontos de observação e controlo são definidos para avaliar o impacte das plumas na zona de influência dos emissários submarinos. A aplicação e desenvolvimento do modelo de dispersão proporciona uma melhor compreensão e controlo dos processos de diluição e dispersão na baía. Os resultados da modelação são utilizados para avaliar a necessidade de desinfeção, que pode reduzir custos operacionais e permitirá um aumento da resiliência do sistema em caso de falhas nas infraestruturas de colheita, transporte e de tratamento de águas residuais e proporcionar um melhor funcionamento e gestão de instalações

A fesability analysis of a novel constructed wetland design tool for Arusha, Tanzania

While water is a resource necessary for all life, in Tanzania alone over 20 million people who live in rural areas have no access to improved water sources. Water stress is a major concern in rural Tanzania, where annual potential evaporation can outpace precipitation by hundreds of mm per year. There is a significant need for improved access to water sources for Tanzanians living in rural regions of Arusha. To improve access to water, both water quantity and quality need to be addressed in a treatment system. Various water collection and treatment systems were compared and contrasted through the lens of appropriate technology. Sub surface flow (SSF) constructed wetlands and ultrafiltration systems were selected for development. ^ Constructed wetlands have a history of water treatment dating back hundreds of years. SSF constructed wetlands are an appropriate solution for water stress in the Arusha region due to their low cost, low maintenance requirements, and pre-treatment. To help establish a baseline water quality of surface water in Arusha, water was collected from various sources across the region. While they were tested for multiple parameters, turbidity and bacterial contaminants were identified and confirmed as the primary pollutants of concern. To help design constructed wetlands in the region a tool was built in Excel. The tool incorporates rainfall, runoff, and other environmental factors to produce information for sizing and availability to help project planners design a constructed wetland. ^ The developed tool was applied to the Nelson Mandela African Institute of Science and Technology (NM-AIST) campus and the village of Endallah. A pilot scale wetland was designed for the NM-AIST campus for testing and validating of the tool, and a wetland was designed for the village of Endallah based on incoming runoff and consumption by the villagers. These applications demonstrated how the tool can be used and applied to other places by project planners in the field of water management.

Recreational Water Illnesses

The safety of recreational waters is affected by numerous variables such as the microbiological and chemical quality of water, the number and health conditions of the users, and the correct functioning of all technological installations used for water treatment. By evaluating the various health risks related to exposure to swimming pools, spas, and surface waters, this Special Issue seeks to address the proper management of waters used for recreational purposes, both in natural and built environments. This Issue contains 12 scientific papers. The first four, three of which are literature reviews, illustrate the epidemiological picture of infections related to recreational waters, by describing cases and outbreaks caused by both traditional and emerging microorganisms. The following four papers concern the microbiological monitoring of swimming pools, gardens, estuarine areas, and therapeutic spas. Two of these also analyse the distribution of antibiotic-resistant bacteria and the associated transmission risks. The relationship between microbial indicators and pathogens in recreational water is analysed by the following two papers, one of which is an experimental study on the survival of Salmonella and Escherichia coli in estuarine bank sediments and the other of which is an exhaustive literature review. The last two papers are focused on the development of risk control approaches, including the validation of questionnaire methods to quantify recreational water ingestion and the application of traditional and innovative technologies in water treatment

Contaminant biotransport by Pacific salmon to Lake Michigan tributaries

The Great Lakes are ideal systems for evaluating the synergistic components of environmental change, such as exotic species introductions and legacy pollutants. Introduced Pacific Salmon (Oncorhynchus spp.) represent an intersection of these drivers because they are non-native species of economic importance that bioaccumulate contaminants during the open water phase of their life cycle. Furthermore, Pacific salmon can deliver a significant pulse of contaminated tissue to tributaries during spawning and subsequent death. Thus, salmon represent a key pathway by which contaminants accumulated in Lake Michigan are transported inland to tributaries that otherwise lack point source pollution. Our research has revealed that salmon exhibit basin-specific persistent organic pollutant (POP) and mercury (Hg) concentrations reflecting pollutant inputs from both current and historic sources. Overall, Lake Michigan salmon were more contaminated with POPs and Hg than conspecifics from Lakes Huron or Superior. Consequently, Lake Michigan salmon pose a higher risk and magnitude of contaminant biotransport and transfer. Resident stream fish (e.g., brook trout) sampled from salmon spawning reaches had higher pollutant concentrations than fish sampled from upstream reaches lacking salmon, but the extent of fish contamination varied among lake basins and streams. In general, Lake Michigan tributaries were the most impacted, suggesting a direct relationship between the extent of salmon-derived contaminant inputs and resident fish contaminant levels. Within and among lake basins, contaminant biotransport by salmon is context dependent and likely reflects a suite of ecological characteristics such as species identity and trophic position, dynamics of the salmon run, watershed land-use, and instream geomorphology such as sediment size. We suggest that future management of salmon-mediated contaminant biotransport to stream communities in the Great Lakes basin should consider biological, chemical, and physical factors that constitute the environmental context

More people, more food, worse water? a global review of water pollution from agriculture

Current patterns of agricultural expansion and intensification are bringing unprecedented environmental externalities, including impacts on water quality. While water pollution is slowly starting to receive the attention it deserves, the contribution of agriculture to this problem has not yet received sufficient consideration. We need a much better understanding of the causes and effects of agricultural water pollution as well as effective means to prevent and remedy the problem. In the existing literature, information on water pollution from agriculture is highly dispersed. This repost is a comprehensive review and covers different agricultural sectors (including crops, livestock and aquaculture), and examines the drivers of water pollution in these sectors as well as the resulting pressures and changes in water bodies, the associated impacts on human health and the environment, and the responses needed to prevent pollution and mitigate its risks