With progressing urbanisation, treatment of urban stormwater is a vital issue that should be addressed to ensure good water quality in receiving water bodies. Treatment may be performed near the source, with different filter systems using various filter materials, or by using an end-of-pipe method, e.g. a stormwater pond. One constraint in the urban environment is the lack of available space in developed areas, where stormwater treatment facilities are needed the most. Methods developed to treat the stormwater runoff have been the focus of previous studies but the increasing standards of water quality and increasing land constraint pressures demand the further development of stormwater treatment systems. Both laboratory and field experiments are necessary to understand and improve the treatment processes as well as to evaluate how the implemented methods perform under field conditions. The aim of the thesis was to increase the knowledge about the components in stormwater treatment systems that can be used in area-efficient treatment facilities. In order to compare four potential stormwater filter materials (peat, bark, air-blown polypropylene and milkweed), column experiments were carried out using synthetic stormwater that simulated road runoff. Experiments were carried out to evaluate the impacts of the ageing of synthetic stormwater quality during laboratory testing, including dissolved metal concentrations and their impact on the estimation of filter efficiency. In a field study, a full-scale application of a zeolite filter installation was investigated, with a focus on service life and the efficiency of treating copper roof runoff. In order to further investigate a novel sedimentation device, a bottom grid structure (BGS), promoting sediment settling in a smaller area of a stormwater pond, a hydraulic modelling study was conducted to investigate the impact of the cell geometry of the structure on sediment settling and the impact of the structure on pond maintenance and sediment resuspension.  The column tests of four different filter materials showed that bark and peat had higher treatment efficiency for dissolved metals than milkweed and polypropylene, with the order of efficiency being peat>bark>milkweed>polypropylene. All four of the filter materials showed a total metal reduction of over 70%, which could be due to the separation of particle-bound metals in the columns. The ageing of the synthetic stormwater showed that dissolved metals, particularly copper, decreased in concentration, quite rapidly. During one experiment run, the dissolved copper concentration was reduced to 15% of its initial value. In order to account for the concentration changes an equation was proposed that normalised the concentration of dissolved metal over the duration of the experiment. During the observation period of 16 months, the zeolite installation removed 52% to 82% and 48% to 94% of total and dissolved copper, respectively. However, the effluent concentrations were still high (360-600 μg/l). There was also an indication of the decreasing filter performance over time with a prediction that the treatment level of total copper would drop to approximately 25% by the end of the service life of three years. The hydraulic experiments on a scaled model of a BGS showed that wider cells were on average 13% more efficient in trapping the particles than the narrower variant. The cell wall angle also had an impact (tilted walls added to the sedimentation efficiency), although the applicability of such cell structures can be questioned, as this cell shape may hinder maintenance efforts. It was also hypothesised that the inclusion of the BGS in the pond reduces the area needed for sediment settling, thus making the pond more area-efficient and easier to include in an urbanised setting.

The Sustainable Development Goals (SDGs) affect societal development within multiple sectors, both strategically and at street level. For instance, SDG 6 and SDG 11 have contributed to a shift in urban stormwater management that has traditionally been pipe-based, including only control of runoff volumes, to a more multi-functional nature-based blue-green infrastructure (BGI), where"blue" areas are characterized by (temporarily or permanent) open water and "green" areas by vegetative systems. As an alternative drainage approach, the use of BGI was developed and primarily evaluated in regions with temperate climates where a recent focus has been the role of BGI as providers of multiple ecosystem services within an urban context. However, as the use of BGI expands into non-temperate zones, there is a clear need to address the fact that these nature-based systems are not only blue and green. For example, in northern climates BGI systems e.g., street-scale bioretention systems include white aspects (i.e. snow) for varying time periods. Whilst the design options for bioretention are varied and complex, (e.g., differing combinations of construction styles, filter materials and plants) research into the impact of alternative design options has focused on technical evaluations, i.e., the impact on pollution treatment and/or hydraulic control of stormwater. Knowledge of how these different bioretention designs affect other sustainability criteria, such as economic, social, and environmental aspects, needs to be fully developed. The purpose of this licentiate thesis was to characterise and compare different street-scale bioretention designs to gain a better understanding of the relative sustainability of different bioretention systems and how the use of BGI can contribute to SDG delivery. In addition, the aim was to lay the theoretical foundation for an extended BGI concept by including white urban environments within the concept of blue-green-white infrastructure (BGWI). The overall goal was to contribute with new, relevant knowledge about the relative sustainability of alternative design aspects for bioretention systems in particular and the implications for BGI in general. A review of the literature informed the identification and approaches to benchmarking a series of social, economic, and technical-environmental criteria. In a life cycle assessment and a multi-criteria analysis, 12 different designs of bioretentions were evaluated. The results showed that, although design features had a large impact on the performance of bioretentions, no single design configuration scored highest across all sustainability criteria. The best performance in relation to social criteria was associated with the use of trees and smaller volumes of pumice in the filter material mixture. In the economic criteria, costs increased when using concrete constructions and a complex mixture of filter materials. Bioretention systems with a water-saturated submerged zone and a variety of plant species outperformed the other systems in the technical-environmental criteria. The foundation of and justification for the concept of BGWI was developed in a perspective essay, including the development of a theoretical framework to support the systematic expansion of BGI to BGWI and to inform and align future studies. The framework identifies the potential for the delivery of a wider range of ecosystem services via BGWI in comparison to BGI. However, while the technical functionality of BGI in temperate climates has an established evidence base, its performance in cold climates (as BGWI) is less well evaluated with the extension of the BGI concept to BGWI identified as an opportunity to address these knowledge gaps in a way that is sensitive to seasonal variations in ecosystem service delivery (both positive and negative). The results from this licentiate thesis can be directly used in both the strategic and practical planning of sustainable urban stormwater management strategies. Specifically in the early planning stage of BGI, design considerations should be made that recognise the differing role of BGI across seasons as an opportunity to aid multifunctional urban drainage implementation and thereby, the sustainable development of cities.

Stormwater can be a potential water resource if it is treated, and the quality meets the demand, depending on the application. Various nutrients and pollutants, for example microorganisms can enter stormwater and can vary depending on time and place, as the contaminants come from different sources. Sometimes the quality of stormwater can also deteriorate during its collection and storage. Therefore, the treatment of stormwater could be necessary before reuse and before discharge into the environment. Various treatment methods exist for this purpose. Ponds, wetlands, and bioretention systems are used in various countries to remove pollutants from stormwater. In addition to these methods, the use of membranes for stormwater treatment has become of interest. The application of membrane technology in new areas such as stormwater treatment requires a great deal of research to evaluate the potential opportunities and challenges. Research has been conducted to separate one or a few pollutants from stormwater using membranes. However, more research is needed to evaluate the applicability of using membranes for stormwater treatment, and their challenges and advantages. For this purpose, three experimental studies have been carried out. Polluted snow along a road was collected and treated using an ultrafiltration membrane. To prevent any damages to the membrane, a pretreatment step was included before the membrane process. It was of interest to evaluate the membrane process ability for treating snowmelt and to evaluate the potential for water reuse depending on regulations in different countries. Another objective was to investigate the productivity of the membrane process and try to improve it by adding pulsatile fluid flow to the experimental set-up. To investigate membrane cleaning, backwashing was carried out at regular intervals, and different backwash times and two chemical cleaning combinations were used. In addition, the fouling layer on the membrane was studied using a scanning electron microscope. Afterwards, the quality of the backwash water from the membrane cleaning was analyzed, which may be helpful in the future when looking for a suitable method to recycle the backwash water. When evaluating pulsatile fluid flow, the productivity of the membrane process increased significantly as the frequency of pulses increased (from -6.6 to 82 L/m2/h). The treated snowmelt mixture was of high quality and could be used for various applications, such as wetland maintenance, toilet flushing, and other municipal use. If the treated stormwater is disinfected, it can also be reused as drinking water. In this study, the optimal backwash duration was found to be 45 s in relation to productivity, although the backwash efficiency and permeability were higher with a backwash time of 60 s. The use of chemicals (NaOH with or without NaOCl followed by HCl) could restore the pure water permeability of the membrane to 107 L/m2/h/bar-1, in average. The pure water reversibility after chemical cleaning was 96% on average. Analysis of the backwash water showed that it is a concentrated solution of stormwater pollutants. TOC concentration was 24 times higher than pretreated stormwater. In addition, the backwash water contained significant concentrations of particulate metals and the concentration factor for various metals varied between 15 to 40.

The studies which this thesis is based on assessed the stormwater quality in a highway catchment located in Sundsvall, Sweden, and examined the performance of a gross pollutant trap (GPT)-biofilter stormwater treatment train (TT) downstream of the catchment, in terms of removal efficiency, intra-event variability, and environmental risk reduction of organic micropollutants (OMPs) for the receiving water body. Assessing the occurrence and event mean concentrations (EMCs) of all OMPs in the catchment revealed that bisphenol A (BPA), octylphenol (OP), nonylphenol (NP), five carcinogenic and four non-carcinogenic polycyclic aromatic hydrocarbons (PAHs), and C16-C40 fractions of petroleum hydrocarbons (PHCs) all potentially pose an environmental risk to freshwater (EMCs >PNEC: predicted non-effect concentration), while alkylphenolethoxylates, six low- molecular weight PAHs, and lighter fractions of PHCs (C10-C16) do not occur at problematic levels. In order to assess the impact of the downstream TT in mitigating the risks of the studied OMPs, the performance of the TT compartments (a GPT followed by three filter cells) was analyzed and then compared with each other to identify the importance of each design feature (i.e. pre-treatment GPT, sand-based filter media, vegetation, and chalk amendment). Overall, the TT removed most OMPs from highway runoff effectively. The GTP did not contribute to this treatment, thus, the filter sections were responsible for most of the OMP removal. The results showed that, although the non-vegetated sandfilter (SF) could moderately (<50% removal for phenolic substances) to substantially (50–80% removal for PAHs and PHCs) treat the OMPs, the vegetated biofilters (BF and BFC) considerably improved the removal performance, especially for BPA, OP, and suspended solids (TSS). This observation was explained by additional filtration processes provided by the vegetation topsoil layer, which not only enhanced the particulate/particle-bound OMP physical retention but also physiochemical adsorption of colloidal and soluble substances/fractions (such as BPA and OP). Further analysis of intra-event concentration (IEC) variations of OMPs and TSS showed that the IECs in the highway stormwater and GPT outflow varied considerably without any particular patterns over the course of the events, but first flush rarely occurred. The IEC variations were attenuated by the SF and BFC cells so that more even pollutant load discharge with no first flush was observed during the filter cells’ outflow events. Yet, the IECs for the SF cell revealed that the IECs often peak at the beginning of the effluent events (within the first 100 m3 out of maximum record of ⁓600 m3) and then decrease and become stabilized towards the end of the event. The early-phase concentration peaks exceeded the PNECs for TSS, five PAHs, BPA, and OP, a fact that was not shown by the EMC-based analysis, thus highlighted the advantage of the IEC analysis.

​Uppsala är en av åtta städer som på begäran av regeringen valts ut för uppdraget hållbar stadsutveckling. Projektet arbetar med stadsdelen Bergsbrunna i Uppsala där kommunen planerar att exploatera. Området planeras att täcka Uppsalas södra delar. På beställning av Uppsala kommun har en undersökning gjorts för olika lösningar inom vattenanvändning. Undersökningen ska ge ett underlag för kommunens exploateringsplaner för hållbar stadsutveckling. Detta för att kunna svara på hur vattenanvändningen ser ut med dagens tekniker i jämförelse med nya möjliga lösningar. Uppsala kommun kommer senare använda data för lösningarna som undersöks i denna rapport för att modellera vattenanvändning i modelleringsprogrammet LEAP. Enligt Uppsala Vatten använder en Uppsalabo i snitt 140 L dricksvatten per dygn. Denna rapport undersöker flera möjliga lösningar för att minska vattenanvändningen; hur vattenmätare påverkar vattenanvändningen, om regnvatteninsamling är möjligt och i vilken grad regnvatten kan ersätta dricksvatten, vattenbesparande tekniker i hushållet såsom vattenbesparande munstycken, vattencirkulerande dusch samt gråvattenåtervinning, olika tekniker för avloppssystem, stadsodling, dagvattenhantering och vegetationsklädda tak. De kvantifierade lösningarna jämförs med varandra och med Uppsala Vattens förbrukningstal. Minskad dricksvattenanvändning för diskning får störst effekt av munstyckets dimmläge (0,56 L per person och dygn). Minskad dricksvattenanvändning för dusch får störst effekt vid implementering av vattencirkulerande dusch (5,6 L per person och dygn). Minst vattenanvändning för avloppssystem får tekniken med kombination av urinsorterande system och vakuumtoalett (1,1 L per person och dygn). En lösning vars funktion väcker medvetenhet om dricksvattenanvändning hos befolkningen är individuella vattenmätaren, vilken ger en minskning av dricksvattenanvändningen med 20 %. För dagvatten och stadsodling genomförs exempelberäkningar. En riskbedömning för lösningar i denna rapport kan guida vägval. I resultatet visas särskilt två scenarion där lösningar sätts samman med hjälp av sankeydiagram. Det första scenariot visar hur dricksvattenanvändningen skulle förändras med vattenmätare och konventionella snålspolande toaletter. Detta resulterade i en besparing på upp till 31 L dricksvatten per person och dygn. Det andra scenariot kallas för “mest vattenbesparande scenario” och visar kombinationen av de mest vattenbesparande teknikerna, samt ersättning av dricksvatten med regnvatten för områdena övrigt, toalettspolning och tvätt. Detta resulterade i en dricksvattenbesparing på nästan 127 L per person och dygn. Ett resultat är även att vissa tekniker inte bör kombineras för bästa effekt. Kvaliteten på källorna som används i rapporten varierar. För att kunna genomföra beräkningar och komma fram till ett resultat har förenklingar och antaganden gjorts. Projektets begränsade omfattning gör även att många hållbarhetsaspekter bortom vattenanvändning bara berörs ytligt eller har behövts uteslutas helt. Resultaten bör därför inte användas direkt, utan kan ses som guide för fortsatta undersökningar och framtida vägval. Slutsatsen är att nya tekniker och lösningar bör vara standard för hållbar stadsutveckling inom vattenanvändning. Rapporten visar på att det finns ett stort antal möjliga lösningar som kan bidra till att minska vattenanvändningen för en hållbar stadsutveckling. / Uppsala is one of eight cities which, by request from the Swedish government, has been elected for the mission of sustainable urban development. This project centers around the city district Bergsbrunna in Uppsala, which the municipality (Uppsala Kommun) is planning to develop. The area will cover the southern part of Uppsala. By commission of the municipality, a study has been made on different methods in the field of water-use. The study will lay the groundwork for the municipality’s development plans and sustainable urban development. This with the goal to answer how the water-use is made up, with today’s methods compared to with new, possible methods. Data from the methods which have been studied in this project will later be used by Uppsala Kommun to model water-use in the modelling program LEAP.  According to Uppsala Vatten, a person living in Uppsala uses, on average, 140 L of drinking water per day. This project studies several possible methods to reduce water-use; how water-meters affect water-use, if rainwater collection is possible and to which degree drinking water can be replaced by rainwater, water-saving techniques in households such as water-saving nozzles, water circulating showers and grey water reuse, as well as different techniques for sewer systems, urban farming, urban runoff management and green roofs. The quantified methods are compared with each other and with the water consumption given by Uppsala Vatten. For washing-up, the greatest drinking water reduction is given by the nozzle’s mist-mode (0.56 L per person and day). For showering, the greatest drinking water reduction is given by a water circulation shower (5.6 L per person and day). For sewer systems and toilets, the urine sorting vacuum system gives the lowest water-use (1.1 L per person and day). A method, whose function gives awareness concerning water-use amongst the population, is the installation of individual water-meters, which reduces the use of drinking water by 20 %. For urban runoff and urban farming, examples are calculated. A risk assessment for methods studied in this project can be a guide for decision-making. The result particularly shows two scenarios where methods have been combined using Sankey diagrams. The first scenario shows how the drinking water-use would change by implementing water-meters and conventional, water-use reducing toilets. This resulted in a reduction by up to 31 L of drinking water per person and day. The second scenario is called the “most water reducing scenario” and consists of the most water reducing techniques as well as replacement of drinking water by rainwater for the categories toilet flushing, laundry and other. This resulted in a reduction by up to 127 L of drinking water per person and day. Another result shows that some methods should not be combined, for maximum effect. The quality of the references used in this project varies. To perform calculations and obtain results some simplifications and assumptions have been made. The limited extent of the project results in many of the sustainability aspects beyond water-use only being treated superficially or to no extent. Therefore, the result should not be used directly but should instead be seen as a guide to further studies and future decisions. In conclusion, new techniques and methods should be standard for sustainable urban development in water-use. The study shows that there are a great number of possible methods that can contribute to a reduction in water-use and sustainable urban development / Uppsala Energy Stories (UES)

No description available.

Hydrological drainage/river basins constitute highly heterogeneous systems of coupled natural and anthropogenic water and pollutant flows across political, national and international boundaries. These flows need to be appropriately understood, quantified and communicated to stakeholders, in order to appropriately guide environmental water system management. In this thesis, various uncertainties about water and pollutant flows in drainage/river basins and their implications for effective and efficient water pollution abatement are investigated, in particular for mine-related heavy metal loadings in the Swedish Dalälven River basin and for nitrogen loadings in the Swedish Norrström drainage basin. Economic cost-minimization modeling is used to investigate the implications of pollutant load uncertainties for the cost-efficiency of catchment-scale abatement of water pollution. Results indicate that effective and efficient pollution abatement requires explicit consideration of uncertainties about pollution sources, diffuse contributions of the subsurface water system to downstream pollutant observations in surface waters, and downstream effects of different possible measures to reduce water pollution. In many cases, downstream load abatement measures must be used, in addition to source abatement, in order to reduce not only expected, but also uncertainties around expected pollutant loads. Effective and efficient environmental management of water systems must generally also consider the entire catchments of these systems, rather than focusing only on discrete pollutant sources. The thesis presents some relatively simple, catchment-scale pollutant flow analysis tools that may be used to decrease uncertainties about unmonitored water and pollutant flows and subsurface pollutant accumulation-depletion and diffuse loading to downstream waters.

This project was initiated to fill knowledge gaps on the occurrence of pathogens in different streams of wastewater, e.g. greywater and domestic wastewater. The aims were also to measure the removal of pathogens in different treatment processes, conventional and innovative, and correlate the removal to that of common microbial process indicators, such as faecal coliforms, enterococci, Cl. perfringens spores and bacteriophages. One study also assessed the correlation between the removal of microorganisms and some commonly measured physico-chemical process indicators. The results can be applied in microbial risk assessments (MRAs) of urban wastewater systems. Indicators and parasitic (oo)cysts were enumerated with standard methods and viruses with rtPCR. High levels of Giardia cysts and enteroviruses were found in untreated wastewater (103.2 and 104.2 L-1 respectively) indicating high incidences in the society. Noroviruses were also often found in high numbers (103.3 L-1) during winter, but less frequent and in lower numbers (102.3 L-1) during the rest of the year. This temporal variation correlated to the clinical laboratory reporting of noroviruses. A temporal variation was also shown for Giardia with significantly lower cyst counts in untreated wastewater during spring. Cryptosporidium oocysts were not as numerous in untreated wastewater (5 L-1) reflecting a lower incidence in the society than for the other pathogens during the time of the study. Since temporal variation had a larger impact than spatial, site-specific measurements may not be necessary to perform screening level MRAs of wastewater discharge and reuse. Good data can be found in the literature and corrected for by recovery of the detection method, flow and incidence in the society. Removal of microorganisms in wastewater treatments varied from 0 to >5.8 log due to process combination and organism in question. Treatment in integrated hydroponics removed microorganism more efficiently than did secondary conventional treatment, though having longer hydraulic retention time. Tertiary treatment and treatment in a membrane bioreactor (MBR) showed better removal potential than treatment in upflow anaerobic sludge blankets (UASB) in a pilot plant. Human virus genomes were less removed and Giardia cysts more removed than all of the studied indicators. Enumeration with PCR, however, may underestimate infectious virion removal. Spores of sulphite-reducing anaerobes and somatic coliphages were significantly less removed than E. coli and enterococci in all the studied processes. Bacterial indicator and spore removals correlated to enterovirus genome removal (p<0.05), but the predictive values were low (R<0.4). Removals between microbial indicators and NH4-N, Kjeldal-N, COD and TOC correlated stronger (10-18<p<0.02; 0.43<R<0.90). To manage the risk with reuse and discharge of wastewater, treatment performance targets have been calculated as a step in a hazard analysis and critical control point (HACCP) approach. These targets varied from 0 to 10.4 log removal due to water (grey or wastewater), organism (rotavirus, Campylobacter or parasitic (oo)cysts) and exposure (drinking water, surface water, aerosols, irrigation of crops or public parks). Faecal contamination in greywater was measured by coprostanol and was shown to be 980 times lower than in wastewater, corresponding to 2.9 log removal in treatment. Somatic coliphages were suggested to function as an index of virus removal in wastewater treatment processes as well as to be included in the monitoring of bathing water. The guideline level was suggested to be 300 PFU 100 mL-1 based on MRA of enteroviruses. This level in a water sample would equal a probability of infection of 0.3% (95th percentile 4%). The risk is overestimated if animal sources dominate the faecal pollution. Development in methods to track sources of faecal pollution showed that if somatic coliphages are enumerated together with phages infecting Bacteroides strain GA17, discriminating human from animal faecal pollution is possible based on the ratio between the phages / QC 20101013

Rapporten är ett resultat av en undersökning som initierades av att man i Motala kommun ville sluta använda sig av kloramin för dricksvattendesinfektionen vid sitt ytvattenverk i Råssnäs. Man ville utesluta ammoniak vid dricksvattenframställningen och övergå till att enbart desinficera med hypoklorit. Råssnäs tar sitt råvatten från Vättern och det färdiga vattnet distribueras sedan upp till 30 km från verket. I samband med att man ville göra förändringen var man intresserad av att veta hur man utför desinfektion vid andra vattenverk med liknande förutsättningar d.v.s. råvatten från Vättern och långa distributionsvägar. Med utgångspunkt från dessa förutsättningar valdes kommunerna Askersund och Jönköping samt kommunalförbundet Skaraborgsvatten ut för att tillfrågas om hur man där arbetar med sin dricksvattendesinfektion. Undersökningen begränsas av att endast tre kommunala aktörer deltog men dessa bedömdes vara de som bäst uppfyllde de angivna förutsättningarna. Från de avgivna svaren kan man dra slutsatsen att båda metoderna, desinfektion med kloramin eller enbart hypoklorit, används och tycks fungera bra. Problem uppstår i första hand under den varma delen av året då vattnet i ledningarna värms upp vilket kan främja den mikrobiella tillväxten. Åtgärden blir i sådana fall i första hand att utföra stödklorering ute på nätet. Desinfektions metoderna mella kommunerna/kommunalförbundet varierar. I Askersund doseras endast hypoklorit och man har inga erfarenheter från andra metoder. I Jönköping har man i sitt största verk nyligen övergått från kloramin till enbart hypoklorit och fick i samband med detta under den första tiden många klagomål på dålig smak och lukt hos dricksvattnet. Problemen avtog efterhand och efter ett halvår hade klagomålen upphört. Man tror att störningarna uppstod då biofilmen i ledningsnätet regerade på den kraftigare kloreringen för att därefter gradvis anpassa sig till nya förhållanden. Skaraborgsvatten använder sig av både förklorering med hypoklorit samt efterklorering med klor och ammoniak. Halva klormängden bildar då kloramin med ammoniaken medan den andra halvan reagerar med en momentan desinficerande effekt. De erhållna svaren visar också att UV-ljus används, eller planeras att användas, och byggs ut inom verksamheten hos alla de tre tillfrågade dricksvattenproducenterna. Rådet till Motala blir att man provar att avsluta ammoniakdoseringen och övergår till enbart hypoklorit. Dock bör man under en tid efter förändringen, för att undvika att störningar uppstår, utöka kontrollen av vattnet genom extra provtagning på lämpliga platser ute i ledningsnätet och då framförallt efter sommaren då vattnet är som varmast. Det är även lämpligt att förbereda för att kunna stödklorera, förslagsvis ute vid tryckstegringsstaioner, samt att ytterligare bygga ut användningen av UV-ljus ute på nätet vid t.ex. tryckstegringar och reservoarer.

<p>Hydrological drainage/river basins constitute highly heterogeneous systems of coupled natural and anthropogenic water and pollutant flows across political, national and international boundaries. These flows need to be appropriately understood, quantified and communicated to stakeholders, in order to appropriately guide environmental water system management. In this thesis, various uncertainties about water and pollutant flows in drainage/river basins and their implications for effective and efficient water pollution abatement are investigated, in particular for mine-related heavy metal loadings in the Swedish Dalälven River basin and for nitrogen loadings in the Swedish Norrström drainage basin. Economic cost-minimization modeling is used to investigate the implications of pollutant load uncertainties for the cost-efficiency of catchment-scale abatement of water pollution.</p><p>Results indicate that effective and efficient pollution abatement requires explicit consideration of uncertainties about pollution sources, diffuse contributions of the subsurface water system to downstream pollutant observations in surface waters, and downstream effects of different possible measures to reduce water pollution. In many cases, downstream load abatement measures must be used, in addition to source abatement, in order to reduce not only expected, but also uncertainties around expected pollutant loads. Effective and efficient environmental management of water systems must generally also consider the entire catchments of these systems, rather than focusing only on discrete pollutant sources. The thesis presents some relatively simple, catchment-scale pollutant flow analysis tools that may be used to decrease uncertainties about unmonitored water and pollutant flows and subsurface pollutant accumulation-depletion and diffuse loading to downstream waters.</p>