Modelling the effects of socioeconomic development and climate change on the microbial water quality in Lake Mälaren
Activities in the watershed of a drinking water source can pose health risks to drinking water consumers. Consequently, socioeconomic development is important when predicting microbial water quality. Socioeconomic development can be described using Shared Socioeconomic Pathways (SSPs). In addition, climate change alters meteorological parameters, thereby affecting flow regimes as well as fate and transport of microorganisms. Climate change scenarios can be defined using Representative Concentration Pathways (RCPs).
The aim of this thesis is to use water quality modelling to assess the effects of socioeconomic development and climate change on the microbial water quality in Lake Mälaren – a drinking water source for approximately two million people.
This project will be performed in
contact with Helene Ejhed at the drinking water producer Norrvatten in
Sweden and Nynke Hofstra at the Wageningen University in the
Modelling drinking water treatment in combination with quantitative microbial risk assessment to account for climate change effects
Drinking water treatment needs to be dimensioned to address the microbial risks and produce safe drinking water. Aim:
The aim of this project is to improve quantitative microbial risk assessment (QMRA) approach to account for the dependencies between the different steps in the drinking water treatment plant. In this project, a simplified model of a drinking treatment plant will be developed and coupled with the existing QMRA tool, in order to account for dependency between the different treatment steps and thus the effects of sub-optimal treatment in previous steps. Objectives:
- to identify (simpler) models of treatment train in literature;
- to build on an existing model or develop a simplified model for the treatment train; the model will have a focus on climate change effects and associated risks.
- To couple the model to the existing QMRA tool.
Supervisor, Mia Bondelind, firstname.lastname@example.org Supervisor and Examiner,
Ekaterina Sokolova, email@example.com
Modelling fate and transport of perfluorinated compounds in Lake Ekoln
Lake Ekoln is polluted with perfluorinated (PFOS) compounds. Pollutant reach the lake with wastewater discharges from Uppsala, through the esker that got polluted due to fire extinguishing exercises at the Ärna airport, and through the air. PFOS is very stable in the environment and can be transported long distances. Through Lake Ekoln. pollutants can reach Lake Mälaren and the water intake of the Görnväln drinking water treatment serving 600 000 consumers in Stockholm and neighbouring municipalities. In a previous project, a hydrodynamic model of Lake Ekoln was set-up in MIKE 3 by DHI software. In this MSc thesis project, this model will be used to simulate the spread of PFOS with the lake.
The aim is to analyse pathways, transport times, and trends for PFOS in Lake Ekoln. The existing hydrodynamic model of Lake Ekoln will be used to simulate the spread of PFOS and test scenarios that can lead to critical situations.
This project will be performed in contact with drinking water producer Norrvatten.
Optimising flocculation and filtration under conditions of changing climate using hydrodynamic modelling
Natural organic matter (NOM) may have a negative effect on drinking water treatment, and the concentrations of NOM increase under conditions of changing climate.
The aim of this thesis is to evaluate how hydrodynamic modelling of water temperature and NOM in the water source can be used to optimise the flocculation and filtration treatment steps at the drinking water treatment plant.
Risk assessment for drinking water sources
Public health and economic development rely on access to and the quality of drinking water. Drinking water systems are, however, exposed to a wide range of risks due to e.g. human activities, societal development, aging infrastructure and climate change. Industrial and agricultural activities, accidents, infrastructure projects, and urban development in general may cause harm to water sources. Drinking water sources are also key components in supply systems of many other goods and services, from food production and process industry to aesthetic and recreational services. Hence, we must assess existing risks to enable an efficient protection of drinking water sources and prioritisation of protective measures. However, there is a need to further develop existing methods and approaches for risk assessment of water sources. We also need additional knowledge on how specific contamination sources and other hazards can affect the different services a water sources provides, including raw water for drinking water supply.
The aim of this project is to perform a risk assessment of a drinking water source (a specific case will be identified together with the student), focusing on one or several contamination sources or hazards that may affect the water availability. The effects of possible mitigation measures will also be estimated. The specific methods or models to be used will be identified based on the hazards to be analysed.
In an ongoing research project, WaterPlan (Risk-based prioritization of water protection in sustainable spatial planning), we aim to develop methods and approaches that enable well-informed analyses and prioritization of measures for protecting drinking. This thesis work will be part of the WaterPlan project
Quantitative microbial risk assessment (QMRA) and climate change
Waterborne gastrointestinal diseases are a major contributor to the global disease burden and mortality. Recent research suggests that the entire drinking water system may suffer due to climate change; and that extreme weather events will increase the incidence of waterborne diseases. Current scientific understanding regarding the impact of climate change on overall public health risk remains ambiguous. To assess drinking water safety, the World Health Organisation recommends a risk-based approach encompassing all steps of the drinking water supply system from the catchment to the consumer. In this light, Quantitative Microbial Risk Assessment (QMRA) is widely used to analyse and inform the management of the drinking water supply system. Generic QMRA tools have been developed to perform QMRA for specific drinking water treatment plants with different treatment trains and varying pathogen levels in the source water. There are also examples of QMRA being applied to quantify relative infection risks for selected waterborne pathogens under different climate change scenarios. Currently, there are several QMRA tools available with different capabilities. In this MSc thesis, these tools will be compared with special focus on their suitability to assess the effects of climate change on microbial risks
The aim is to compare the available QMRA tools and evaluate their suitability to account for climate change effects on the microbial health risks for drinking water consumers.
This project will be performed in contact with Julia Derx at the Vienna University of Technology, Austria.
Study of online sensors in drinking water system
Around 30% of the water-borne gastro-intestinal (GI) infections in drinking water systems originates from events and failures in the distribution network. Leakage (holes/cracks) in distribution systems may cause intrusion of contaminated water in the drinking water pipes and is one important factor to health problems.
The aim of this study is to carry out a study on sensor installations in Sydvatten’s/NSVA’s distribution systems, which parameters should be monitored to detect leakage and thus also assess health risks (QMRA). Water meters may be equipped with both pressure sensors and quality sensors to detect leakage. • Suggest an online sensor system in Helsingborg.
Sustainable maintenance of urban water systems – to walk the walk
Urban water systems (UWS) include water, wastewater and stormwater pipes. Failure occurring in the UWS can substantially affect society (e.g drinking water availability, basement floodings and discharge of pollutants). Many of the UWS pipes in Sweden were installed before 1970. To mitigate increasing number of failures (e.g. pipe bursts and leakages) in the UWS, the need for a higher rehabilitation rate in the future has been acknowledged. Maintaining and keeping these systems in adequate condition is essential for the delivery of safe drinking water.
Rehabilitation and investments in buried infrastructure are often expensive and maintenance needs to be planned both short and long term in order to spend resources effectively. In academic literature there are many different types of decision support models that can describe and evaluate the UWS and analyse the need for reinvestments, aiding water utilities in the asset management process. However, models in asset management and there is a need to connect the academia and the industry.
Aim and objectives:
- Interview small and medium size water utilities
- Map the current situation regarding the use of decision support models in maintenance in small and medium sized utilities
- Identify hinders for, as well as key aspects that can aid, municipalities in the implementation of available decision support models
The municipalities will benefit from the results by bridging the gap between academic knowledge and practical application. Identifying the municipality need is the first step towards the development of a more comprehensive decision support model for maintaining UWS. Additionally, municipalities will be able to gain knowledge from and inspire eachother based on the interviews. The results will be used further in the research program Mistra InfraMaint to develop methods for sustainable maintenance of infrastructure.
The thesis may be written by 1-2 students. At least one of the students should be able to read and speak Swedish. It is an advantage (but not mandatory) to have taken courses related to drinking water engineering, risk assessment and decision support.
Uppehållstid för vatten i Larslundsåsen
NOVF har sedan 1960 infiltrerat vatten i åsen vid Larslund. Erfarenhet från driftansvarig sägs att I början på 2000 talet gjordes ett infiltrationsförsök i damm 1. Då användes ett konstgjort salt. Saltet indikerades efter ca 30 dagar. Det finns ingen dokumentation på detta och verksamheten vet inte vilken brunn eller brunnsområde som saltet indikerades. Under 2016 började verksamheten göra en MBA analys. I och med den behövde verksamheten ta reda på mer exakt om uppehållstiden. Alternativ har utredds hur mätningen ska gå till. Att blanda vanligt koksalt och infiltrera den mättade saltlösningen blev den metod som valdes. Metoden visade sig inte vara tillförlitlig då saltet aldrig nådde uttagsbrunnarna. Inget salt kunde detekteras under 4 månader. Den troligaste orsaken till att saltet aldrig kom fram är att det sjunkit på djupare nivå ä våra uttagsbrunnar eller ”åkt iväg” på lerskikt i åsen.
Syftet med infiltrationsförsöket är att mäta uppehållstiden för vattnet från det att det släpps i dammarna till dess att vattnet tas upp i brunnsområdena.
Examensarbetaren behöver fundera ut hur ett infiltrationsförsök kan genomföras samt vilka underlag som behövs för att kunna ta fram ett program för infiltration. Examensarbetaren leder projektet, skriver projektplan, utformar tidplan, uppskattar kostnader, utformar journal och dokumenterar resultat och speciella händelser i projektet. Gör en uppföljning varje vecka för att gå igenom resultat. För en dialog med Laboratoriet i Nyköping angående vilka prover som ska analyseras. Gör en uppföljning för slutrapport. Under projektet finns tillgång till verksamhetschef och driftansvarig för NOVF.
Projektet genomförs i samarbete med NOVF, Nyköping-Oxelösunds Vattenverksförbund