| 1. |
- Amir Heidari, Payam, 1989, et al.
(författare)
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A state-of-the-art model for spatial and stochastic oil spill risk assessment: A case study of oil spill from a shipwreck
- 2019
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 126, s. 309-320
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Tidskriftsartikel (refereegranskat)abstract
- Oil spills are serious environmental issues that potentially can cause adverse effects on marine ecosystems. In some marine areas, like the Baltic Sea, there is a large number of wrecks from the first half of the 20th century, and recent monitoring and field work have revealed release of oil from some of these wrecks. The risk posed by a wreck is governed by its condition, hazardous substances contained in the wreck and the state of the surrounding environment. Therefore, there is a need for a common standard method for estimating the risks associated with different wrecks. In this work a state-of-the-art model is presented for spatial and stochastic risk assessment of oil spills from wrecks, enabling a structured approach to include the complex factors affecting the risk values. A unique feature of this model is its specific focus on uncertainty, facilitating probabilistic calculation of the total risk as the integral expected sum of many possible consequences. A case study is performed in Kattegat at the entrance region to the Baltic Sea to map the risk from a wreck near Sweden. The developed model can be used for oil spill risk assessment in the marine environment all over the world.
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| 2. |
- Bergion, Viktor, 1986, et al.
(författare)
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Accounting for Unexpected Risk Events in Drinking Water Systems
- 2021
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Ingår i: Exposure and Health. - : Springer Science and Business Media LLC. - 2451-9685 .- 2451-9766. ; 13:1, s. 15-31
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Tidskriftsartikel (refereegranskat)abstract
- Unexpected risk events in drinking water systems, such as heavy rain or manure spill accidents, can cause waterborne outbreaks of gastrointestinal disease. Using a scenario-based approach, these unexpected risk events were included in a risk-based decision model aimed at evaluating risk reduction alternatives. The decision model combined quantitative microbial risk assessment and cost–benefit analysis and investigated four risk reduction alternatives. Two drinking water systems were compared using the same set of risk reduction alternatives to illustrate the effect of unexpected risk events. The first drinking water system had a high pathogen base load and a high pathogen log10 reduction in the treatment plant, whereas the second drinking water system had a low pathogen base load and a low pathogen Log10 reduction in the treatment plant. Four risk reduction alternatives were evaluated on their social profitability: (A1) installation of pumps and back-up power supply, to remove combined sewer overflows; (A2) installation of UV treatment in the drinking water treatment plant; (A3) connection of 25% of the OWTSs in the catchment area to the WWTP; and (A4) a combination of A1–A3. Including the unexpected risk events changed the probability of a positive net present value for the analysed alternatives in the decision model and the alternative that is likely to have the highest net present value. The magnitude of the effect of unexpected risk events is dependent on the local preconditions in the drinking water system. For the first drinking water system, the unexpected risk events increase risk to a lesser extent compared to the second drinking water system. The main conclusion was that it is important to include unexpected risk events in decision models for evaluating microbial risk reduction, especially in a drinking water system with a low base load and a low pathogen log10 reduction in the drinking water treatment plant.
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| 3. |
- Bergion, Viktor, 1986, et al.
(författare)
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Economic Valuation for Cost–Benefit Analysis of Health Risk Reduction in Drinking Water Systems
- 2020
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Ingår i: Exposure and Health. - : Springer Science and Business Media LLC. - 2451-9685 .- 2451-9766. ; 12:1, s. 99-110
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Tidskriftsartikel (refereegranskat)abstract
- Microbial risk mitigation measures in drinking water systems aiming at preventing gastrointestinal disease can provide substantial societal health benefits if implemented properly. However, the procedure of including and monetising the health benefits in cost–benefit analysis (CBA) has been somewhat scattered and inconsistent in the literature, and there is a need for a comparison of available methods. First, through a literature review, we identified the methods to include health benefits in decision support and to monetise these benefits in CBA. Second, we applied the identified health valuation methods in a case study. In the case study, we investigated if changing the health valuation method could change the rank order of the decision alternatives’ net present values. In the case study a risk-based decision model that combined quantitative microbial risk assessment and CBA was used. Seven health valuation methods were identified, each of them including different aspects of health benefits. The results of the case study showed that the choice of the health valuation method can change the rank order of decision alternatives with respect to their net present values. These results highlight the importance of choosing an appropriate health valuation method for the specific application. Although this study focused on the drinking water context, the identified health valuation methods can be applied in any decision support context, provided that input in terms of the health risk reduction is available.
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| 4. |
- Bergion, Viktor, 1986, et al.
(författare)
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Hydrological modelling in a drinking water catchment area as a means of evaluating pathogen risk reduction
- 2017
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Ingår i: Journal of Hydrology. - : Elsevier BV. - 0022-1694. ; 544, s. 74-85
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Tidskriftsartikel (refereegranskat)abstract
- Waterborne outbreaks of gastrointestinal diseases are of great concern to drinking water producers and can give rise to substantial costs to the society. The World Health Organisation promotes an approach where the emphasis is on mitigating risks close to the contamination source. In order to handle microbial risks efficiently, there is a need for systematic risk management. In this paper we present a framework for microbial risk management of drinking water systems. The framework incorporates cost-benefit analysis as a decision support method. The hydrological Soil and Water Assessment Tool (SWAT) model, which was set up for the Stäket catchment area in Sweden, was used to simulate the effects of four different mitigation measures on microbial concentrations. The modelling results showed that the two mitigation measures that resulted in a significant (p
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| 5. |
- Bergion, Viktor, 1986, et al.
(författare)
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Risk-based cost-benefit analysis for evaluating microbial risk mitigation in a drinking water system
- 2018
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 132, s. 111-123
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Tidskriftsartikel (refereegranskat)abstract
- Waterborne outbreaks of gastrointestinal diseases can cause large costs to society. Risk management needs to be holistic and transparent in order to reduce these risks in an effective manner. Microbial risk mitigation measures in a drinking water system were investigated using a novel approach combining probabilistic risk assessment and cost-benefit analysis. Lake Vomb in Sweden was used to exemplify and illustrate the risk-based decision model. Four mitigation alternatives were compared, where the first three alternatives, A1-A3, represented connecting 25, 50 and 75%, respectively, of on-site wastewater treatment systems in the catchment to the municipal wastewater treatment plant. The fourth alternative, A4, represented installing a UV-disinfection unit in the drinking water treatment plant. Quantitative microbial risk assessment was used to estimate the positive health effects in terms of quality adjusted life years (QALYs), resulting from the four mitigation alternatives. The health benefits were monetised using a unit cost per QALY. For each mitigation alternative, the net present value of health and environmental benefits and investment, maintenance and running costs was calculated. The results showed that only A4 can reduce the risk (probability of infection) below the World Health Organization guidelines of 10−4 infections per person per year (looking at the 95th percentile). Furthermore, all alternatives resulted in a negative net present value. However, the net present value would be positive (looking at the 50th percentile using a 1% discount rate) if non-monetised benefits (e.g. increased property value divided evenly over the studied time horizon and reduced microbial risks posed to animals), estimated at 800–1200 SEK (€100–150) per connected on-site wastewater treatment system per year, were included. This risk-based decision model creates a robust and transparent decision support tool. It is flexible enough to be tailored and applied to local settings of drinking water systems. The model provides a clear and holistic structure for decisions related to microbial risk mitigation. To improve the decision model, we suggest to further develop the valuation and monetisation of health effects and to refine the propagation of uncertainties and variabilities between the included methods.
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| 6. |
- Dahlqvist, Peter, et al.
(författare)
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Potential benefits of managed aquifer recharge MAR on the Island of Gotland, Sweden
- 2019
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Ingår i: Water. - : MDPI AG. - 2073-4441. ; 11:10
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Tidskriftsartikel (refereegranskat)abstract
- The Island of Gotland (3000 km2), east of mainland Sweden, suffers from insufficient water availability each summer. Thin soils and lack of coherent reservoirs in the sedimentary bedrock lead to limited reservoir capacity. The feasibility of Managed Aquifer Recharge (MAR) is explored by identifying suitable areas and estimating their possible contribution to an increased water availability. MARis compared to alternative water management measures, e.g., increased groundwater abstraction, in terms of costs and water availability potential. Results from GIS analyses of infiltration areas and groundwater storage, respectively proximity to surface water sources and surface water storage were classified into three categories of MAR suitability. An area of ca 7700 ha (2.5% of Gotland) was found to have good local conditions for MAR and an area of ca 22,700 ha (7.5% of Gotland) was found to have moderate local conditions for MAR. These results reveal the MAR potential on Gotland. The water supply potential of MAR in existing well fields was estimated to be about 35% of the forecasted drinking water supply and 7% of the total water demand gap in year 2045. It is similar in costs and water supply potential to increased surface water extraction. © 2019 by the authors.
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| 7. |
- Georgiou, C., et al.
(författare)
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Self-stabilization overhead: A case study on coded atomic storage
- 2019
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Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - Cham : Springer International Publishing. - 1611-3349 .- 0302-9743. ; 11704 LNCS, s. 131-147
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Konferensbidrag (refereegranskat)abstract
- Shared memory emulation on distributed message-passing systems can be used as a fault-tolerant and highly available distributed storage solution or as a low-level synchronization primitive. Cadambe et al. proposed the Coded Atomic Storage (CAS) algorithm, which uses erasure coding to achieve data redundancy with much lower communication cost than previous algorithmic solutions. Recently, Dolev et al. introduced a version of CAS where transient faults are included in the fault model, making it self-stabilizing. But self-stabilization comes at a cost, so in this work we examine the overhead of the algorithm by implementing a system we call CASSS (CAS Self-Stabilizing). Our system builds on the self-stabilizing version of CAS, along with several other self-stabilizing building blocks. This provides us with a powerful platform to evaluate the overhead and other aspects of the real-world applicability of the algorithm. In our case-study, we evaluated the system performance by running it on the world-wide distributed platform PlanetLab. Our study shows that CASSS scales very well in terms of the number of servers, the number of concurrent clients, as well as the size of the replicated object. More importantly, it shows (a) to have only a constant overhead compared to the traditional CAS algorithm and (b) the recovery period (after the last occurrence of a transient fault) is no more than the time it takes to perform a few client (read/write) operations. Our results suggest that the self-stabilizing variation of CAS, which is CASSS, does not significantly impact efficiency while dealing with automatic recovery from transient faults.
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| 8. |
- Gärtner, Nadine, 1990, et al.
(författare)
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Integrating Ecosystem Services into Risk Assessments for Drinking Water Protection
- 2022
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Ingår i: Water (Switzerland). - : MDPI AG. - 2073-4441 .- 2073-4441. ; 14:8
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Tidskriftsartikel (refereegranskat)abstract
- Water protection is a widely supported goal in society, but competing interests often complicate the implementation of water protection measures. Moreover, the benefits of protection efforts are typically underestimated as risk assessments focus on the provision of drinking water and neglect the additional services provided by a clean drinking water source. We developed a list of water system services (WSS) that allows assessment of all biotic and abiotic services provided by a drinking water source. The WSS were derived from the Common International Classification of Ecosystem Services (CICES). The objectives of this paper are to (i) introduce the concept of WSS, (ii) describe a procedure on how to develop a region-specific list of WSS and present a list of WSS specifically tailored to Sweden, (iii) present how to integrate WSS into a risk assessment for drinking water, and (iv) illustrate a practical application on a Swedish case study. The results, presented as an assessment matrix, show the provided services and contrast the hazard sources with their impact on all services. The WSS assessment can be used to communicate and negotiate the extent of water protection measures with relevant stakeholders and illustrate synergies and trade-offs of protective measures beyond drinking water protection.
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| 9. |
- Hassellöv, Ida-Maja, 1974, et al.
(författare)
-
Miljörisker sjunkna vrak
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Arbetet med en nationell strategi för hantering av miljöfarliga vrak påbörjades 2007 med Statskontorets utredning Vrak och ägarlösa båtar, men ingen enskild myndighet har tilldelats övergripande ansvar för vrakfrågan. Utöver ansvarsfrågan har också förväntade höga kostnader för inspektion och sanering av vrak fördröjt det fortsatta arbetet. Ett steg närmare en nationell strategi redovisas här genom regeringsuppdraget Miljörisker sjunkna vrak. Genom samordning och ökat informationsutbyte mellan berörda myndigheter finns stor potential att minska de förväntade kostnaderna för inspektion av vrak och omgivande miljö. Om den föreslagna strategin antas, beräknas informationsläget avseende vraken att snabbt förbättras så att det år 2030 inte längre finns några potentiellt miljöfarliga vrak i svenska vatten.Havs- och vattenmyndigheten (HaV) och Naturvårdsverket har idag delat ansvar för övervakning och åtgärdande av miljögifter i marin miljö. Mot denna bakgrund hade det varit naturligt att låta HaV få ett övergripande ansvar för hantering av miljöfarliga vrak. Genom flexibelt upplägg avseende tidsramar bedöms övervakning och inspektion av potentiellt miljöfarliga vrak kunna utföras genom att HaV ger de berörda myndigheterna uppdrag; kartering och sjömätning (Sjöfartsverket), ROV och dykinspektion (Kustbevakningen och/eller Försvarsmakten), sediment- och bottenförhållanden (Statens geologiska undersökning). En förutsättning är dock väl fungerande samverkan och kommunikation mellan berörda myndigheter. Existerande plattformar för detta finns redan på såväl operativ nivå i form av Projekt ”Sjöstjärnan” - samordning och samverkan mellan myndigheter avseende information och inhämtning av djup- och bottendata; respektive högsta ledningsnivå i form av Samordningsgruppen för havs- och vattenmiljöfrågor (SamHav).Enligt Sjöfartsverkets tidigare inventering (Miljörisker från fartygsvrak, 2011) finns det utmed Sveriges kust knappt tre tusen vrak som inte kan avskrivas utan vidare informationsinhämtning. Drygt trehundra av dessa klassades som potentiellt miljöfarliga. Av dessa har 31 listats som de sannolikt mest miljöfarliga vraken. Listan över de 31 vraken har därför varit utgångspunkt för projektet Miljörisker sjunkna vrak, vars syfte var att ta fram en metod för prioritering och inspektion av potentiellt miljöfarliga vrak.Undervattensinspektion av vrak är kostsamt och kostnaden ökar kraftigt om vrakets läge är otillgängligt. Av de 31 vraken valdes därför nio relativt lättillgängliga vrak ut för noggrannare arkivstudier, samt sjömätning. Utifrån informationen från arkivstudierna och sjömätningen gjordes ett ytterligare urval om fyra vrak (Altnes, Skytteren, Thetis och Villon), vilka även inspekterades med ROV och/eller dykare. Huvudsyftet var att, inför och under arbetet med inspektionerna, utarbeta Standard Operating Procedures (SOPs) som framgent kan användas som stöd inför kommande operationer rörande potentiellt miljöfarliga vrak.Under arbetet med inspektionerna observerades inte några pågående läckage av olja från vraken. Trots denna positiva information är det viktigt att komma ihåg att endast bevis på tomma tankar kan fullt ut avskriva vraken från listan över potentiellt miljöfarliga vrak. Även om det under projektets fältarbete inte observerades läckage av olja, finns dokumenterade läckage sedan tidigare (senast 2008-04-26) för Skytteren. Noterbart är också att Kustbevakningen 2014-06-29, fick rycka ut för att omhänderta olja som börjat läcka efter vraket Immen, norr om Gotska Sandön. Immen var inte med bland fallstudieobjekten i projektet.I tillägg till undervattensinspektion placerades strömmätningsutrustning ut vid vraken Skytteren och Villon. Strömdata kan sedan användas för att modellera ett hypotetiskt spill av olja från ett vrak och ge en indikation på var läckage av olja kan tänkas påverka den marina miljön negativt. Exempel på sådana negativa effekter kan vara försämrad förmåga hos sedimentlevande organismer att omsätta näringsämnen, vilket i sin tur kan påverka hela det marina ekosystemet. Strömdata är också ett viktigt underlag för utformning av övervakningsprogram, exempelvis med passiva provtagare för att detektera läckage av miljöfarlig substans från vrak.Samtlig insamlad data kommer att användas för att validera riskbedömningsverktyget VRAKA, som möjliggör resurseffektiv prioritering av vilka vrak som bör undersökas och/eller saneras. VRAKA, SOPs för inspektion, samt tillgång till specifik kompetens för utvärdering av samtliga resultat är nyckelelement för att kunna presentera en tillförlitlig riskbedömning av potentiellt miljöfarliga vrak. Havs- och vattenmyndigheten skulle kunna vara lämplig myndighet med huvudansvar för miljöfarliga vrak, i operativ samverkan med övriga berörda myndigheter.
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| 10. |
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| 11. |
- Hassellöv, Ida-Maja, 1974, et al.
(författare)
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Miljörisker sjunkna vrak II. Undersökningsmetoder och miljöaspekter
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- During 2015 the Swedish Maritime Administration continued the second phase of thegovernmental task Environmental risks from sunken wrecks which first report was finalized2014-10-31 (Dnr: 1399-14-01942-6).The main conclusions from the 2014 report remain; for future handling of potentially pollutingshipwrecks it is recommended that the Swedish Agency for Water and Marine Management isgiven a coordinating responsibility in close cooperation with other competent nationalauthorities, such as Swedish Maritime Administration, Swedish Coastguard, Swedish NationalMaritime Museums, the Geological Survey of Sweden, SMHI, Swedish EPA, and SwedishCivil Contingencies Agency. Through coordination of wreck related operations and activitieswithin the concerned competent authorities’ ordinary areas of responsibility, resourceefficiency is improved. The estimated extra cost for implementation of a national strategy forhandling of the wrecks are estimated to be 10-15 MSEK which should be allocated to thecompetent authorities by the Swedish Agency for Water and Marine Management.The conclusions from 2014 was reinforced during 2015, e.g. through the validation of the riskassessment model VRAKA, which is now available in a first operative version. Additionalecotoxicological experiments on the development of tolerance against PAHs in meiofauna andmicroorganism communities were conducted in a field study in Brofjorden. The mainconclusions from this work is that comprehensive analyzes of PAHs should include alkylatedPAHs, and that exposure to PAHs over time can lead to tolerance development in ammoniumoxidizing bacteria, at the expense of their ability to perform the essential ecosystem servicenitrification.Continued measurements of the bottom currents were made at the wrecks Villon and Skytteren,and at the dumping area west of Måseskär. Measurement series yielded important informationon how measuring equipment at the wreck can be deployed in an optimized way in futuremonitoring program; to calculate the possible spreading of pollution from a wreck, currentmeasurements should be performed upstream from the wreck site, while sensors for thedetection of, for example, oil should be put into the turbulence downstream of the wreck.The current measurement instruments (RDCP) deployed at the Måseskär dump site was trawledup after only three weeks of measurements, but still gave valuable information on the extensivebottom trawling that resuspend (stir up) sediments. Earlier geochemical surveys have shownsignificantly elevated arsenic concentrations in the area and sediment resuspension greatlyincreased the risk for spread of any contaminants in the area. Trawling is not prohibited in thearea, and the current lack of knowledge regarding potential effects on human health whenconsuming seafood from dump areas calls for reflection upon the suitability of trawling in thearea.In addition to the current measurements Swedish Maritime Administration and the SwedishNavy conducted hydrographic survey with multibeam and side scan sonar and ROVinvestigation of the wrecks in the dumping area at Måseskär. 28 wrecks were found, and ROVinvestigation showed cargo holds with dumped torpedoes or mines and other containers in some SjöfartsverketDnr: 1399-14-01942-156of the wrecks. There is some discrepancy between the previously measured elevated arsenicconcentrations in the Måseskär area and recently presented data from historical archives thatdoes not support the theory that chemical weapons were dumped in the area. However, there isa very good correlation between the dominant current direction in the area, and the highestmeasured arsenic concentrations in the area downstream of the wrecks, suggesting some formof arsenic source in the area.
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| 12. |
- Koundouri, P., et al.
(författare)
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Methodology for Integrated Socio-economic Assessment of Multi-use Offshore Platforms.
- 2017
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Ingår i: In: Koundouri P. (eds) The Ocean of Tomorrow. Environment & Policy, vol 56. Springer, Cham. - 9783319557700 ; , s. 11-26
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This chapter presents the methodology employed for the Integrated Socio-Economic Assessment (MISEA) of different designs of Multi-Use Offshore Platforms (MUOPs). The methodology allows for the identification, the valuationand the assessment of the potential impacts and their magnitude. The analysis considers a number of feasible designs of MUOP investments, and the likely responsesof those impacted by the investment project. The approach provides decision-makers with a valuable tool to assess whether a MUOP project increases the overall social welfare and hence should be undertaken. This is performed under alternative specifications regarding platform design, the discount rate and the stream of net benefits, if a Cost-Benefit Analysis (CBA) is to be followed or a sensitivity analysis of selected criteria in a Multi-Criteria Decision Analysis (MCDA) framework. Themethodology can support the implementation of policies aiming at achieving a goodenvironmental status of the EU’s marine waters and the protection of the resource base upon which marine-related economic and social activities depend.
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| 13. |
- Landquist, Hanna, 1984, et al.
(författare)
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A fault tree model to assess probability of contaminant discharge from shipwrecks
- 2014
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Ingår i: Marine Pollution Bulletin. - : Elsevier BV. - 0025-326X .- 1879-3363. ; 88:1-2, s. 239-248
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Tidskriftsartikel (refereegranskat)abstract
- Shipwrecks on the sea floor around the world may contain hazardous substances that can cause harm to the marine environment. Today there are no comprehensive methods for environmental risk assessment of shipwrecks, and thus there is poor support for decision-making on prioritization of mitigation measures. The purpose of this study was to develop a tool for quantitative risk estimation of potentially polluting shipwrecks, and in particular an estimation of the annual probability of hazardous substance discharge. The assessment of the probability of discharge is performed using fault tree analysis, facilitating quantification of the probability with respect to a set of identified hazardous events. This approach enables a structured assessment providing transparent uncertainty and sensitivity analyses. The model facilitates quantification of risk, quantification of the uncertainties in the risk calculation and identification of parameters to be investigated further in order to obtain a more reliable risk calculation.
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| 14. |
- Landquist, Hanna, 1984, et al.
(författare)
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Bayesian updating in a fault tree model for shipwreck risk assessment
- 2017
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 590, s. 80-91
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Tidskriftsartikel (refereegranskat)abstract
- Shipwrecks containing oil and other hazardous substances have been deteriorating on the seabeds of the world for many years and are threatening to pollute the marine environment. The status of the wrecks and the potential volume of harmful substances present in the wrecks are affected by a multitude of uncertainties. Each shipwreck poses a unique threat, the nature of which is determined by the structural status of the wreck and possible damage resulting from hazardous activities that could potentially cause a discharge. Decision support is required to ensure the efficiency of the prioritisation process and the allocation of resources required to carry out risk mitigation measures. Whilst risk assessments can provide the requisite decision support, comprehensive methods that take into account key uncertainties related to shipwrecks are limited. The aim of this paper was to develop a method for estimating the probability of discharge of hazardous substances from shipwrecks. The method is based on Bayesian updating of generic information on the hazards posed by different activities in the surroundings of the wreck, with information on site-specific and wreck-specific conditions in a fault tree model. Bayesian updating is performed using Monte Carlo simulations for estimating the probability of a discharge of hazardous substances and formal handling of intrinsic uncertainties. An example application involving two wrecks located off the Swedish coast is presented. Results show the estimated probability of opening, discharge and volume of the discharge for the two wrecks and illustrate the capability of the model to provide decision support. Together with consequence estimations of a discharge of hazardous substances, the suggested model enables comprehensive and probabilistic risk assessments of shipwrecks to be made.
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| 15. |
- Landquist, Hanna, 1984, et al.
(författare)
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Environmental Risk Assessment of Shipwrecks: a fault-tree model to assess probability of contaminant release
- 2012
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Ingår i: SETAC North America 33rd Annual Meeting.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- RP247 Environmental risk assessment for shipwrecks: a fault-tree model to assess probability of contaminant release H. Landquist, I. Hassellov, Chalmers University of Technology / Shipping and Marine Technology; L. Rosen, Chalmers University of Technology / Civil and Environmental Engineering; F. Lindgren, Chalmers University of Technology / Shipping and Marine Technology; I. Dahllof, The University of Gothenburg; T. Norberg, Chalmers University of Technology / Mathematical Sciences; A. Lindhe, Chalmers University of Technology / Civil and Environmental Engineering. Shipwrecks lying on the sea floor around the world may contain hazardous substances which can cause harm to the maritime environment. Today there are no comprehensive methods for environmental risk assessment of shipwrecks and thus there is poor support for decision-making on prioritisation of mitigation measures. The purpose of this study has been to develop a framework for risk assessment of potentially polluting shipwrecks, focusing on a detailed probabilistic assessment of the release of hazardous substances. The framework is based on international standards for risk management and the assessment of the probability for release was done using fault-tree analysis. This approach enables a structure assessment and provides an excellent possibility of uncertainty and sensitivity analysis. The fault tree model was tested by groups of experts in the field of maritime administration, maritime archaeology and in other areas to validate the method. The developed framework facilitates risk assessment of potentially polluting shipwrecks and can support risk management as well as provide well founded input for decision-making. In particular the fault-tree analysis provides a quantitative method for assessing the probability of leakage and can facilitate uncertainty and sensitivity analyses.
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| 16. |
- Landquist, Hanna, 1984, et al.
(författare)
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Expert elicitation for deriving input data for probabilistic risk assessment of shipwrecks
- 2017
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Ingår i: Marine Pollution Bulletin. - : Elsevier BV. - 0025-326X .- 1879-3363. ; 125:1-2, s. 399-415
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Tidskriftsartikel (refereegranskat)abstract
- The necessity of having a process in place for adequate risk assessment of shipwrecks that pose a threat to the marine environment is today internationally acknowledged. However, retrieving the desired data for such a risk assessment can prove challenging. One means of addressing this problem is to make use of experts' knowledge and experience. The purpose of this paper is therefore to present and analyse data for risk assessment of shipwrecks derived by expert elicitation. The main outcome is the experts' estimations of (i) the generic probability of an opening in a shipwreck due to the occurrence of a number of activities and (ii) estimations of the degree to which site-specific and wreck-specific indicators affect the probability of opening. Results show that the derived information is applicable in probabilistic shipwreck risk assessment and that the VRAKA framework now contains needed information for integrating generic and site-specific information using Bayesian updating.
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| 17. |
- Landquist, Hanna, 1984, et al.
(författare)
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SWERA – Delivery 2.2
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)
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| 18. |
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| 19. |
- Landquist, Hanna, 1984, et al.
(författare)
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VRAKA—A Probabilistic Risk Assessment Method for Potentially Polluting Shipwrecks
- 2016
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Ingår i: Frontiers in Environmental Science. - : Frontiers Media SA. - 2296-665X. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Shipwrecks around the world contain unknown volumes of hazardous substances which, if discharged, could harm the marine environment. Shipwrecks can deteriorate for a number of reasons, including corrosion and physical impact from trawling and other activities, and the probability of a leakage increases with time. Before deciding on possible mitigation measures, there are currently few comprehensive methods for assessing shipwrecks with respect to pollution risks. A holistic method for estimating environmental risks from shipwrecks should be based on well-established risk assessment methods and should take into account both the probability of discharge and the potential consequences. The purpose of this study was therefore to present a holistic risk assessment method for potentially polluting shipwrecks. The focus is set to developing a method for estimating the environmental consequences of potential discharges of hazardous substances from shipwrecks and to combine this with earlier research on a tool for estimating the probability of discharge of hazardous substances. Risk evaluation should also be included in a full risk assessment and is the subject of further research. The consequence assessment was developed for application in three tiers. In Tier 1, the probability of discharge and possible amount of discharge are compared to other shipwrecks. In Tier 2, a risk matrix, including a classification of potential consequences, is suggested as a basis for assessment and comparison. The most detailed level, Tier 3, is based on advanced tools for oil spill trajectory modeling and sensitivity mapping of the Swedish coast. To illustrate the method an example application on two wrecks is presented. Wreck number 1 present a lower probability of discharge and a lower consequence in a Tier 1 and Tier 3 assessment. For the Tier 2 consequence assessment, the two example wrecks present equal consequence. The tool for estimating the probability of discharge of hazardous substances from shipwrecks, and the approach for consequence estimation, offers a comprehensive method for assessing the risks presented by potentially polluting shipwrecks. The method is known as VRAKA (short for shipwreck risk assessment in Swedish) and provides decision support, facilitating prioritization of risk mitigation measures enabling efficient use of available resources.
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| 20. |
- Lindhe, Andreas, 1981, et al.
(författare)
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Användningen av MACRO-DB i tillståndsärenden och effekter av ny modellversion: Enkätstudie och samhällsekonomisk analys av arbetet med MACRO-DB
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I syfte att skydda dricksvattentäkter, dvs. yt- och grundvattenresurser, kan användningen av växtskyddsmedel regleras genom att exempelvis ställa krav på tillstånd för yrkesmässig användning inom vattenskyddsområden. Att bedöma när, hur och vilka växtskyddsmedel som kan spridas kan vara komplicerat. För att underlätta arbetet med att både ta fram och handlägga tillståndsärenden finns därför modellverktyget MACRO-DB. Verktyget har utvecklats av SLU Centrum för kemiska bekämpningsmedel i miljön (CKB) och används för att simulera bekämpningsmedelsläckage till yt- och grundvatten och bedöma om risken är acceptabelt låg eller inte. År 2018 gjordes en satsning där både Havs- och vattenmyndigheten (HaV) och CKB gjorde investeringar för att vidareutveckla MACRO-DB. Syftet med analysen som presenteras i denna rapport har varit att utvärdera om satsningen varit samhällsekonomiskt motiverad med hjälp av en kostnads-nyttoanalys (KNA). För att ta fram nödvändigt underlag och ge en bild av dagens arbete med tillståndsärenden för yrkesmässig användning av växtskyddsmedel på jordbruksmark inom vattenskyddsområden har en enkätundersökning genomförts. Enkäten skickades till samtliga svenska kommuner och syftade specifikt till att kartlägga användningen av MACRO-DB. Den genomförda enkätstudien besvarades av 58 % av Sveriges kommuner och bedöms baserat på detta och den geografiska spridningen ge en bra bild av dagens arbete med tillståndsärenden för användning av växtskyddsmedel på jordbruksmark inom vattenskyddsområden och specifikt användningen av MACRO-DB. Av de kommuner som besvarat enkäten är det 71 % som handlägger den aktuella typen av ärenden och av dessa är det 61 % som använder MACRO-DB som del av beslutsunderlaget. En majoritet av kommunerna använder såldes MACRO-DB. Bland de som inte använder MACRO-DB beror det framför allt på att man inte känner verktyget. Endast en mindre andel anser att det är inte rimligt att ställa krav på användning av MACRO-DB i den typ av ärenden de hanterar. Av de kommuner som använder MACRO-DB gör 55 % egna körningar för att kontrollera resultaten som lämnas in med tillståndsansökningarna. En stor andel (44 %) gör i stället granskningar av underlagsmaterial och antaganden. Enligt drygt hälften (53 %) av kommunerna tar dricksvattenproducenten del av uppgifter om vilka växtskyddsmedel som används inom vattenskyddsområden, i syfte att anpassa kontrollen av förekomst av växtskyddsmedelsrester i rå- och dricksvatten. Resultaten från enkäten visar också att majoriteten av kommunerna som använder MACRO-DB (93 %) anser att verktyget fungerar bra (61 %) eller mycket bra (32 %) som hjälpmedel. De förslag som lämnats på hur användningen skulle kunna förbättras innefattar bland annat behov av utbildning och annan stöttning men även behovet av mindre tidskrävande simuleringar. Att reducera simuleringstiden har varit ett av syftena med den uppdatering av MACRO-DB som gjorts och är en av de nyttor som ingår i den genomförda KNA:n. I analysen har fokus varit på följande kostnader och nyttor: (i) investeringarna som HaV och CKB gjort, (ii) tidsvinster som den nya modellversionen ger för kommuner, rådgivare och andra aktörer, (iii) möjliga effekter av en ökad livsmedelproduktion om det blir möjligt att söka tillstånd för spridning av växtskyddsmedel på odlingsmark där det idag råder förbud, och (iv) förlust av miljönyttor som en ökad spridning av växtskyddsmedel kan ge upphov till. Utifrån de antaganden som scenarierna i KNA:n bygger på bedöms nyttorna kunna överstiga kostnaderna, vilket alltså indikerar att satsningen på nya MACRO-DB kan vara samhällsekonomiskt motiverad. Skillnaden mellan nyttor och kostnader är samtidigt inte så betydande att ett annat resultat helt kan uteslutas, det vill säga att kostnaderna skulle kunna överstiga nyttorna. Scenarierna bygger på flera antaganden som är osäkra och de presenterade resultaten över samhällsekonomisk lönsamhet bör därför tolkas med viss försiktighet. Det kan dock konstateras att nyttorna till följd av tidsbesparingar är i samma storleksordning som investeringskostnaderna, vilket innebär att satsningen kan vara samhällsekonomiskt även om endast dessa aspekter beaktas. Osäkerheterna bedöms vara störst i de uppskattade nyttorna av ökad livsmedelsproduktion samt de minskade miljönyttorna. Dessa poster i KNA:n beskriver för- respektive nackdelarna som uppstår om det blir möjligt att söka tillstånd för spridning av växtskyddsmedel på odlingsmark där det idag rådet förbud. Resultaten visar att även dessa nyttor och kostnader är i samma storleksordning. Det kan därför konstateras att såväl möjligheten att bruka marken för livsmedelproduktion som skyddet av yt- och grundvattenresurser är förknippade med stora nyttor. Skyddet av yt- och grundvattenresurserna behöver därför säkerställas samtidigt som åtgärderna inte ska vara onödigt långtgående så att de ger orimliga restriktioner i markanvändningen och i detta fall effekter på livsmedelproduktionen. Verktyg och hjälpmedel som MACRO-DB är därför viktiga för att möjliggöra en rimlig avvägning när risken spridning av växtskyddsmedel kan tillåtas och när det inte är rimligt. I handläggningen av tillståndsärenden och avvägningar om det ska råda förbud eller krav på tillstånd är den inte bara spridningen av växtskyddsmedel som behöver beaktas utan även övriga förutsättningar och risker som hanteringen av växtskyddsmedel är förknippad med.
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| 21. |
- Lindhe, Andreas, 1981, et al.
(författare)
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Approximate dynamic fault tree calculations for modelling water supply risks
- 2012
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Ingår i: Reliability Engineering and System Safety. - : Elsevier BV. - 0951-8320. ; 106:2012, s. 61-71
-
Tidskriftsartikel (refereegranskat)abstract
- Traditional fault tree analysis is not always sufficient when analysing complex systems. To overcome the limitations dynamic fault tree (DFT) analysis is suggested in the literature as well as different approaches for how to solve DFTs. For added value in fault tree analysis, approximate DFT calculations based on a Markovian approach are presented and evaluated here. The approximate DFT calculations are performed using standard Monte Carlo simulations and do not require simulations of the full Markov models, which simplifies model building and in particular calculations. It is shown how to extend the calculations of the traditional OR- and AND-gates, so that information is available on the failure probability, the failure rate and the mean downtime at all levels in the fault tree. Two additional logic gates are presented that make it possible to model a system’s ability to compensate for failures. This work was initiated to enable correct analyses of water supply risks. Drinking water systems are typically complex with an inherent ability to compensate for failures that is not easily modelled using traditional logic gates. The approximate DFT calculations are compared to results from simulations of theorresponding Markov models for three water supply examples. For the traditional OR- and AND-gates, and one gate modelling compensation, the errors in the results are small. For the other gate modelling compensation, the error increases with the number of compensating components. The errors are, however, in most cases acceptable with respect to uncertainties in input data. The approximate DFT calculations improve the capabilities of fault tree analysis of drinking water systems since they provide additional and important information and are simple and practically applicable.
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| 22. |
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| 23. |
- Lindhe, Andreas, 1981, et al.
(författare)
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Cost-effectiveness analysis of risk-reduction measures to reach water safety targets
- 2011
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 45:1, s. 241-253
-
Tidskriftsartikel (refereegranskat)abstract
- Identifying the most suitable risk-reduction measures in drinking water systems requires a thorough analysis of possible alternatives. In addition to the effects on the risk level, also the economic aspects of the risk-reduction alternatives are commonly considered important. Drinking water supplies are complex systems and to avoid sub-optimisation of risk-reduction measures, the entire system from source to tap needs to be considered. There is a lack of methods for quantification of water supply risk reduction in an economic context for entire drinking water systems. The aim of this paper is to present a novel approach for risk assessment in combination with economic analysis to evaluate risk-reduction measures based on a source-to-tap approach. The approach combines a probabilistic and dynamic fault tree method with cost-effectiveness analysis (CEA). The developed approach comprises the following main parts: (1) quantification of risk reduction of alternatives using a probabilistic fault tree model of the entire system; (2) combination of the modelling results with CEA; and (3) evaluation of the alternatives with respect to the risk reduction, the probability of not reaching water safety targets and the cost-effectiveness. The fault tree method and CEA enable comparison of risk-reduction measures in the same quantitative unit and consider costs and uncertainties. The approach provides a structured and thorough analysis of risk-reduction measures that facilitates transparency and long-term planning of drinking water systems in order to avoid sub-optimisation of available resources for risk reduction.
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| 24. |
- Lindhe, Andreas, 1981, et al.
(författare)
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Dynamic Water Balance Modelling for Risk Assessment and Decision Support on MAR Potential in Botswana
- 2020
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Ingår i: Water (Switzerland). - : MDPI AG. - 2073-4441 .- 2073-4441. ; 12:3, s. 721-13
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Tidskriftsartikel (refereegranskat)abstract
- Botswana experiences a water stressed situation due to the climate and a continuously increasing water demand. Managed Aquifer Recharge (MAR) is considered, among other measures, to improve the situation. To evaluate the possibility for increased water supply security, a probabilistic and dynamic water supply security model was developed. Statistically generated time series of source water availability are used in combination with the dynamic storages in dams and aquifers, and the possible supply is compared with the demand to simulate the magnitude and probability of water supply shortages. The model simulates the system and possible mitigation measures from 2013 to 2035 (23 years), using one-month time steps. The original system is not able to meet the demand, and the estimated volumetric supply reliability in the year 2035 is 0.51. An additional surface water dam (now implemented) will increase the reliability to 0.88 but there will still be a significant water shortage problem. Implementing large-scale MAR can further improve the reliability to at least 0.95. System properties limiting the effect of MAR are identified using the model and show how to further improve the effect of MAR. The case study results illustrate the importance and benefit of using an integrated approach, including time-dependence and future scenarios, when evaluating the need and potential of MAR.
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| 25. |
- Lindhe, Andreas, 1981, et al.
(författare)
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Fault tree analysis for integrated and probabilistic risk analysis of drinking water systems
- 2009
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Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 43:6, s. 1641-1653
-
Tidskriftsartikel (refereegranskat)abstract
- Drinking water systems are vulnerable and subject to a wide range of risks. To avoid sub-optimisation of risk-reduction options, risk analyses need to include the entire drinking water system, from source to tap. Such an integrated approach demands tools that are able to model interactions between different events. Fault tree analysis is a risk estimation tool with the ability to model interactions between events. Using fault tree analysis on an integrated level, a probabilistic risk analysis of a large drinking water system in Sweden was carried out. The primary aims of the study were: (1) to develop a method for integrated and probabilistic risk analysis of entire drinking water systems; and (2) to evaluate the applicability of Customer Minutes Lost (CML) as a measure of risk. The analysis included situations where no water is delivered to the consumer (quantity failure) and situations where water is delivered but does not comply with water quality standards (quality failure). Hard data as well as expert judgements were used to estimate probabilities of events and uncertainties in the estimates. The calculations were performed using Monte Carlo simulations. CML is shown to be a useful measure of risks associated with drinking water systems. The method presented provides information on risk levels, probabilities of failure, failure rates and downtimes of the system. This information is available for the entire system as well as its different sub-systems. Furthermore, the method enables comparison of the results with performance targets and acceptable levels of risk. The method thus facilitates integrated risk analysis and consequently helps decision-makers to minimise sub-optimisation of risk-reduction options.
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| 26. |
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| 27. |
- Lindhe, Andreas, 1981
(författare)
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Integrated and Probabilistic Risk Analysis of Drinking Water Systems
- 2008
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Drinking water supply is an essential public function but is at the same time exposed to risks. Since a totally risk-free society is not attainable, risks need to be managed efficiently to achieve an acceptable level of risk. A reliable supply of safe drinking water is vital and the World Health Organization emphasises an integrated risk management approach, including the entire drinking water system from source to tap. An integrated approach is important as there are interactions between different parts of a system. Efficient risk management requires appropriate risk analyses to characterise risk and support decision-making. Risk analysis based on an integrated approach facilitates well-informed decision-making and efficient use of resources for risk reduction. However, guidance on methods for integrated risk analysis of drinking water systems is limited.To support risk management of drinking water systems, a method for integrated and probabilistic risk analysis has been developed and evaluated based on a real-world application. The method is probabilistic in order to include uncertainties of estimates, which always exist due to lack of knowledge and natural variation. A framework for integrated risk management of drinking water systems is also suggested to show the context for risk analysis and to point out important steps in risk management of drinking water systems. The suggested method can be used to model entire systems from source to tap and to include interactions between events. It provides information on risk levels as well as the dynamic behaviour of the system in terms of the failure rate and duration of failures. Furthermore, it enables comparisons of the results with performance targets and acceptable levels of risk. One single method cannot be used to handle all risk-related issues. What is needed instead is a set of tools. The method developed has been shown to facilitate integrated risk analysis from source to tap and thus also informed decision-making, which may assist in minimising sub-optimisation of risk-reduction options. The method is thus one source of input into a set of tools to assist water utilities in risk analysis and risk management.
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| 28. |
- Lindhe, Andreas, 1981, et al.
(författare)
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Integrated risk analysis from source to tap: Case study Göteborg
- 2008
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Ingår i: The 6th Nordic Drinking Water Conference, Oslo, Norway, 9-11 June, 2008. - 9788241402937 ; , s. 231-241
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- To achieve an efficient risk management of a drinking-water system the entire system has to be considered, from source to tap. An important part of risk management is to identify hazards and estimate risks, i.e. to conduct risk analyses. In order to provide a relevant basis for evaluating risks and efficiently prioritising risk reduction options, a risk analysis needs to properly consider interaction between different parts and components of the system. This is especially important in complex systems. Logic tree models have the capability of properly reflect system functionality as well as facilitating quantification of risk levels. A fault-tree model was therefore constructed for an integrated and probabilistic risk analysis of the drinking-water system in Göteborg, Sweden. The main (top) event studied in the analysis was supply failure, which included quantity and quality failures. Quantity failure occurs when no water is delivered to the consumer and quality failure when water is delivered, but unfit for human consumption according to existing water-quality standards. Hard data and expert judgements were used for estimating probabilities of events, consequences and uncertainties of estimates. Monte Carlo simulations were used for the calculations in order to facilitate uncertainty analysis of risk levels. The risk analysis provided information on the probability of failure, rate of failure and mean down time of the system. The number of people affected was also included in the fault tree and risk levels were expressed as Costumer Minutes Lost. The primary aims of this paper were to apply a fault-tree method, for integrated and probabilistic risk analysis of drinking-water systems, on the system in Göteborg and show how the results can be used. The results showed, for example, that the raw water part contributes most to the total risk level and that the distribution part includes frequent failures that most often have a short duration and affect a small number of people. The method was found to facilitate a quantitative and integrated risk analysis of the drinking-water system and the results provide information not only on risk levels, but also on the dynamic behaviour of the system. In addition, the method is capable of relevant handling interaction of system components. Furthermore, it provides transparency and facilitates for formal updating when new information becomes available. Hence, it is concluded that the method provides useful information for discussing and evaluating risks as well as possible risk reduction options.
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| 29. |
- Lindhe, Andreas, 1981, et al.
(författare)
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Quantitative risk assessment of water supply systems from source to tap
- 2009
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Ingår i: TECHNEAU: Safe Drinking Water from Source to Tap. - 1843392755
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In the 3rd edition of the Guidelines for Drinking-water Quality, the World Health Organisation concludes that an integrated management of risks in source waters, treatment systems and distribution networks is the most efficient way to guarantee safe drinking water to consumers. The integrated approach is fundamental to avoid sub-optimisation of risk-reduction efforts. This paper presents an application of an integrated and quantitative risk model for comparing risk-reduction alternatives to support decisions for reaching specified water safety targets. A fault tree approach is used for structuring the risk analysis and for estimating the risk, expressed as Costumer Minutes Lost (CML). Input information is a combination of hard data and expert judgements. Uncertainties in input information are considerable and modelled by a Bayesian statistical approach. The Göteborg drinking water system is used to exemplify model application. Quantitative safety targets have been confirmed at the political level as a basis for long-term planning of investments and reinvestments. Four different risk-reduction alternatives concerning additional raw water supplies and increased treatment capacity were compared. A combination of increased treatment capacity and additional raw water sources was shown to provide the greatest risk reduction. The paper describes how a structured and thorough analysis of risk-reduction options can facilitate transparency and long-term planning of drinking water systems.
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| 30. |
- Lindhe, Andreas, 1981
(författare)
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Risk Assessment and Decision Support for Managing Drinking Water Systems
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The vital importance of a reliable and safe drinking water supply makes efficient risk management necessary for water utilities. Risks must be assessed and possible risk-reduction measures evaluated to provide relevant decision support. The World Health Organization emphasises the use of an integrated approach where the entire drinking water system, from source to tap, is considered when assessing and managing risks. Integrated risk assessments are important in order to avoid overlooking interactions between subsystems and events and to minimise sub-optimisation of risk-reduction measures. Methods for integrated risk assessment are, however, limited. A dynamic fault tree method is presented that enables quantitative, integrated risk assessment of drinking water systems. An approach for approximate dynamic fault tree calculations has been developed to minimise computational demand. It is shown how the method can be used to evaluate uncertainties and provide information on risk levels, failure probabilities, failure rates and downtimes of the entire system and its subsystems. The fault tree method identifies where risk-reduction measures are needed most and different risk-reduction alternatives can be modelled, evaluated and compared. The method is combined with economic analysis to identify the most cost-effective risk-reduction alternative. Integrated risk assessments of drinking water systems are commonly performed using risk ranking, where the probability and consequence of undesired events are assessed using discretised scales. There is, however, no common, structured way of using risk ranking to prioritise risk-reduction measures. Two alternative models for risk-based, multi-criteria decision analysis (MCDA) for evaluating and comparing risk-reduction measures have therefore been developed. The MCDA models are based on risk ranking, they can consider uncertainty in estimates and include criteria related to, for example, different risk types and economic aspects. In summary, this thesis provides methods for integrated risk assessment that make it possible to prioritise risk-reduction measures. It is concluded that the methods provide relevant decision support for efficient risk management in water utilities.
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| 31. |
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| 32. |
- Lindhe, Andreas, 1981
(författare)
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Riskanalys från råvatten till tappkran
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Dricksvattenförsörjningen har en central funktion i samhället och är samtidigt utsatt för ett stort antal risker. För att analysera och hantera dessa risker krävs både lämpliga metoder och en förståelse för de arbetsmoment och aspekter som behöver beaktas. Denna rapport utgör en sammanfattning av licentiatuppsatsen med titeln Integrated and probabilistic risk analysis of drinking water systems, som Andreas Lindhe presenterade vid Chalmers i oktober 2008. För ytterligare redogörelse av det som behandlas i denna rapport hänvisas således till licentiatuppsatsen.Världshälsoorganisationen WHO framhåller att en säker dricksvattenförsörjningen inte uteslutande kan baseras på analyser av färdigproducerat dricksvatten. I stället krävs ett riskbaserat arbetssätt som inkluderar hela försörjningskedjan, från råvatten till tappkran. WHO förespråkar framtagandet av vattensäkerhetsplaner (Water Safety Plans) där bland annat risker skall analyseras och åtgärder föreslås. Vattensäkerhetsplanerna bidrar till en viktig ökad fokus på riskfrågor kopplat till dricksvatten och förväntas bli del av EU:s dricksvattendirektiv. För att möjliggöra det som WHO förespråkar krävs dock lämpliga metoder och verktyg.Tillgången till metoder för att genomföra integrerade riskanalyser av dricksvattensystemet är begränsad. Med integrerad avses att hela systemet, från råvatten till tappkran, inkluderas. En metod baserad på felträdsteknik har utvecklats för att visa hur så kallade integrerade riskanalyser kan genomföras och vilka möjligheter det ger. Ett felträd är en modell som beskriver hur olika händelser förhåller sig till varandra och vad som måste hända för att problem skall uppstå. Med hjälp av metoden kan risken beräknas för hela systemet samt för delar av systemet. Detta ger möjlighet att se hur olika delar av systemet bidrar till den totala risken. Både en kvantitets- och en kvalitetsrelaterad risk beräknas, och de uttrycks som antalet minuter per år den genomsnittlige brukaren (i) blir utan vatten och (ii) får vatten som inte uppfyller kvalitetskraven. Utöver risknivåerna ger modellen information om hur ofta händelser inträffar och hur varaktiga de är.Den framtagna metoden är ett bidrag till den verktygslåda som dricksvattenproducenter världen över bör ha tillgång till för att underlätta arbetet med vattensäkerhetsplaner och riskhantering i stort.
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| 33. |
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| 34. |
- Lindhe, Andreas, 1981, et al.
(författare)
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Uncertainty modelling in multi-criteria analysis of water safety measures
- 2013
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Ingår i: Environment Systems & Decisions. - : Springer Science and Business Media LLC. - 2194-5403 .- 2194-5411. ; 33:2, s. 195-208
-
Tidskriftsartikel (refereegranskat)abstract
- Water utilities must assess risks and make decisions on safety measures in order to obtain a safe and sustainable drinking water supply. The World Health Organization emphasises preparation of Water Safety Plans, in which risk ranking by means of risk matrices with discretised probability and consequence scales is commonly used. Risk ranking enables prioritisation of risks but there is currently no common and structured way of performing uncertainty analysis and using risk ranking for evaluating and comparing water safety measures. To enable a proper prioritisation of safety measures and an efficient use of available resources for risk reduction, two alternative models linking risk ranking and multi-criteria decision analysis (MCDA) are presented and evaluated. The two models specifically enable uncertainty modelling in MCDA and they differ in terms of how uncertainties in risk levels are considered. The need of formal handling of risk and uncertainty in MCDA is emphasised in the literature and the suggested models provide innovations that are not dependent on the application domain. In the case study application presented here, possible safety measures are evaluated based on the benefit of estimated risk reduction, the cost of implementation and the probability of not achieving an acceptable risk level. Additional criteria such as environmental impact and consumer trust may also be included when applying the models. The case study shows how safety measures can be ranked based on preference scores or cost-effectiveness and how measures not reducing the risk enough can be identified and disqualified. Furthermore, the probability of each safety measure being ranked highest can be calculated. The two models provide a stepwise procedure for prioritising safety measures and enable a formalised handling of uncertainties in input data and results.
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| 35. |
- Lindhe, Andreas, 1981, et al.
(författare)
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Utvärdering av statsstödet för bättre vattenhushållning: Enkätstudie av genomförda projekt 2019 och 2020
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Sedan 2019 har det varit möjligt att söka statligt bidrag för åtgärder med syfte att förbättra vattenhushållningen och trygga tillgången på dricksvatten. Bidraget benämns här dricksvattenstödet. I denna rapport presenteras resultaten från en enkätstudie vars syfte varit att utvärdera om dricksvattenstödet bidragit till att trygga tillgången till dricksvatten i Sverige. Enkäten skickades till de som genomfört projekt med finansiering från dricksvattenstödet under åren 2019 och 2020. Totalt besvarades enkäten för 151 projekt, vilket motsvarar 51 % av samtliga projekt som genomfördes under de aktuella åren. Samtliga län som erhållit bidrag från dricksvattenstödet finns också representerade i enkätsvaren. Olika utmaningar ligger bakom de projekt som genomförts, men behov av underlag för strategiska beslut är det vanligaste motivet, följt av bristfällig vattentillgång. För knappt hälften av projekten angavs att de bakomliggande utmaningarna delvis är kopplade till förväntade effekter av klimatförändringar och 13 % svarar ja på frågan. Projektens avsedda effekter är framför allt kopplade till sammanställning eller uppbyggnad av information inom olika områden. Effekter på råvattenförsörjning och kommunala planer är vanligast men andra områden nämns också i många projekt. Av projekten bedöms 88 % helt eller delvis ha uppnått önskad effekt (65 resp. 23 %). Endast 3 % angav att önskad effekt inte uppnåtts (övriga kunde ej bedöma). Vanliga anledningar som anges till varför önskad effekt inte uppnåtts är att projektet är ett steg i arbetet och ytterligare utredning, beslut m.m. krävs. Nästan 40 % av projekten innefattade investering i ny teknik och för dessa projekt bedöms i majoriteten av fallen (87 %) den nya tekniken fungera bra eller mycket bra. En klar majoritet (97 %) av de som besvarade enkäten anser att dricksvattenstödet är viktigt eller mycket viktigt för att trygga dricksvattentillgången. dricksvattenstödets utformning ansågs också vara bra. Det många påpekade som problematiskt var den relativt korta projekttiden. Om denna förlängs skulle det enligt enkätsvaren vara lättare att genomföra det som är planerat i projekten och även utöka projekten, vilket skulle kunna bidra till ytterligare effekter som tryggar tillgången på dricksvatten. Under 2019 och 2020 kunde ettåriga projekt sökas, vilket avspeglar sig i kommentarerna om projektlängden. Numera går det att söka tvååriga projekt. Enkätresultaten visar att om projekten inte erhållit bidrag hade 15 % av dem inte genomförts, men 85 % av projekten hade genomförts på samma sätt som de nu gjorts alternativt med ändringar i tidplan eller omfattning. Stödets utformning gör troligen att dricksvattenstödet framför allt används för att stötta projekt som hade genomförts även utan dricksvattenstödet. Stödet gör det dock möjligt att tidigarelägga vissa åtgärder eller göra mer än vad som annars varit möjligt. Det går inte att ange hur mycket säkrare den svenska dricksvattenförsörjningen blivit till följd av de åtgärder som genomförts med finansiering från dricksvattenstödet. Resultaten från enkätundersökningen visar däremot att dricksvattenstödet har bidragit till projekt som gett en lång rad olika effekter på dricksvattenförsörjningen, vilka också kan kopplas till de utmaningar man ser i branschen. Effekterna som uppnåtts får därför anses ha en positiv effekt på den svenska dricksvattenförsörjningen.
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| 36. |
- Lindhe, Andreas, 1981
(författare)
-
Utvärdering av statsstödet för en säkrad tillgång till dricksvatten och en bättre vattenhushållning - Enkätstudie av genomförda projekt 2019–2022
- 2023
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Mellan år 2019 och 2022 har det varit möjligt att söka statligt stöd i form av bidrag, här benämnt dricksvattenstödet, för åtgärder som syftar till bättre vattenhushållning och bättre tillgången till dricksvatten. I denna rapport presenteras resultaten från en enkätstudie med syfte att utvärdera hur stödet bidragit till att trygga tillgången till dricksvatten i Sverige. Enkäten skickades till kontaktpersonerna för de projekt som beviljats finansiering från dricksvattenstödet under de fyra åren. Totalt besvarades enkäten för 340 projekt, vilket motsvarar 54 % av samtliga genomförda projekt och alla län finns representerade i svaren. Resultaten visar att olika utmaningar ligger bakom de projekt som genomförts, men bristfällig vattentillgång och behov av underlag för strategiska beslut är de vanligaste motiven. Huruvida de bakomliggande utmaningarna är kopplade till klimatförändringarna varierar mellan länen. Sammantaget bedömdes drygt hälften av projekten helt (12 %) eller delvis (40 %) vara kopplade till klimatförändringarna. Projektens avsedda resultat och effekter var framför allt kopplade till sammanställning eller uppbyggnad av information inom olika områden. Effekter på råvattenförsörjning och kommunala planer var vanligast men andra områden nämns också. Av de projekt som beviljades stöd 2019 och 2020 bedömdes 90 % helt eller delvis ha uppnått önskad effekt. Endast 3 % angav att önskad effekt inte uppnåtts (övriga kunde ej bedöma). För projekt som beviljades stöd 2021 bedömde 75 % helt eller delvis ha uppnått avsedda effekter och för 2022 var siffran 34 %, vilket beror på att de flesta projekt inte var avslutade när enkäten besvarades och därmed kunde inte detta bedömas. Vanliga anledningar till varför önskade effekter inte uppnåtts var att projektet är ett steg i arbetet och ytterligare utredning och beslut krävs. Nästan 30 % av projekten innefattade investering i ny teknik och i majoriteten av dessa projekt (80 %) bedömdes den nya tekniken fungera bra eller mycket bra. En klar majoritet (97 %) ansåg att stödet varit viktigt eller mycket viktigt för att trygga tillgången till dricksvatten. Dricksvattenstödets utformning ansågs också vara bra, men projekttiden framhölls som begränsande (1 år 2019–2020). En längre projekttid skulle underlätta genomförandet och även möjliggöra mer omfattande projekt. Från 2021 har det varit möjligt att söka 2-åriga projekt. Utmaningar kopplade till projekttiden nämns dock i enkätsvaren även för projekt beviljade 2021 och 2022. En utmaning som lyftes är långa upphandlingstider, vilket gör det svårt att hinna genomföra det som planerats inom projekten. Enkätresultaten visar att om projekten inte erhållit bidrag hade 16 % av dem inte genomförts och 74 % av projekten hade genomförts på samma sätt som de nu gjorts, alternativt med ändringar i tidplan eller omfattning. Stödets utformning med krav på 50 % medfinansiering gör troligen att dricksvattenstödet framför allt använts för att stötta projekt som hade genomförts även utan stödet. Det har dock gjort det möjligt att tidigarelägga vissa åtgärder eller göra mer än vad som annars varit möjligt. Det går inte att kvantifiera i vilken utsträckning de åtgärder som genomförts bidragit till en trygg och säker dricksvattenförsörjning. Resultaten från enkätundersökningen visar emellertid att stödet har bidragit till genomförande av projekt som gett en lång rad positiva effekter på dricksvattenförsörjningen. Effekterna kan också kopplas till de utmaningar man ser i branschen, inklusive klimatförändringarna. Dricksvattenstödet och åtgärderna anses därför ha bidragit till en trygg och säker dricksvattenförsörjning i Sverige.
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| 37. |
- Lindhe, Andreas, 1981, et al.
(författare)
-
Verktyg för kvantitativ mikrobiologisk riskbedömning (QMRA) av små avloppsanläggningar nära dricksvattenbrunnar – Manual 2016-03-31
- 2016
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna manual är avsedd att ge vägledning för att använda ett nyutvecklat verktyg för kvantitativ mikrobiologisk riskbedömning (QMRA) av små avloppsanläggningar nära dricksvattenbrunnar. Som grund för verktyget ligger projektet Verktyg för mikrobiell riskanalys av små avloppsanläggningar nära dricksvattenbrunnar, finansierat av Havs- och vattenmyndigheten inom ramen för anslag 1:12 Åtgärder för havs- och vattenmiljöer. Den teoretiska bakgrunden till detta verktyg (QMRA-verktyget) med redogörelse för antaganden, men även en kortfattad manual, har tidigare redovisats tillsammans med ett fältförsök med bakteriofager i markens mättade grundvattenzon. QMRA-verktyget ska kunna användas av tillsynsmyndigheten för att analysera risken för smittspridning från befintliga avloppsanläggningar men också i planeringssyfte vid bedömning av rimliga säkerhetsavstånd och placering av nya små avlopp och dricksvattenbrunnar. Verktyget är utformat enligt grunderna för kvantitativ mikrobiologisk riskbedömning som inkluderar fyra huvudsteg: faroidentifiering, exponeringsbedömning, dos-respons-bedömning och riskkarakterisering. Modellutvecklingen har framförallt varit inriktad på exponeringsbedömningen och att ta fram en modell som beaktar den barriäreffekt som uppnås via slamavskiljaren, biohuden, transport i markens omättade zon samt transport i markens mättade grundvattenzon. Speciellt fokus har riktats mot transporten och avskiljningen i mättad grundvattenzon. Modellen är fritt tillgänglig som en webb-länk och kräver ingen installation på den egna datorn, även om möjlighet finns till detta.I denna manual beskrivs indata och hur en modellering genomförs, steg för steg. QMRA-verktyget kan ses som ett komplement och fördjupande verktyg i arbetet med att bedöma den smittorisk som små avloppsanläggningar medför. Under hösten 2015 genomfördes utbildningsseminarier under en dag i Uddevalla, Alingsås respektive Norrtälje kommun riktade till miljö- och hälsoskyddsinspektörerna. Under dessa seminarier fick deltagarna dels föreläsningar inom mikrobiologi, riskbedömning och hydrogeologi, dels en presentation av modellverktyget. Deltagarna fick själva testa verktyget på medhavda exempel. Utöver att sprida kunskap om verktyget syftade seminarierna till att generera erfarenhet och underlag för att förbättra verktyget. Den version av QMRA-verktyget som beskrivs i denna manual är en produkt av genomförda seminarier. I ett avslutande kapitel redovisas modelljusteringar samt några av de viktigaste aspekterna som diskuterades vid seminarierna.
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| 38. |
- Lindhe, Andreas, 1981, et al.
(författare)
-
Verktyg för mikrobiell riskanalys (MRA) av små avloppsanläggningar nära dricksvattenbrunnar – Modellutveckling och fältförsök
- 2015
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Föreliggande rapport utgör slutredovisningen av projektet Verktyg för mikrobiell riskanalys av små avloppsanläggningar nära dricksvattenbrunnar, som finansierats av Havs- och vattenmyndigheten inom ramen för anslag 1:12 Åtgärder för havs- och vattenmiljöer. I utlysningen konstateras att små avlopp utgör ett betydande problem och att det därför är viktigt att stimulera fortsatt utveckling inom verksamhetsområdet.Projektet som redovisas i denna rapport fokuserade på smittspridning från små avlopp till närliggande dricksvattenbrunnar. Ett verktyg i form av en datormodell för mikrobiell riskanalys (MRA) anpassad till enskilda avlopp har utvecklats och ett fältförsök har genomförts för att få ökad kunskap om virustransport i grundvatten. Projektet har genomförts i samarbete mellan Chalmers tekniska högskola (DRICKS – Centrum för dricksvattenforskning), Tyréns AB och Sveriges geologiska undersökning. Folkhälsomyndigheten och Norges miljø- og biovitenskapelige universitet (NMBU) har genomfört vattenanalyser. Representanter från Uddevalla kommun, Trollhättans Stad och Alingsås kommun har tillhandahållit synpunkter på den MRA-modell som utvecklats.Författarna vill rikta ett stort tack till Uddevalla kommun och speciellt Tony Grantz som medverkat i projektet och praktiskt bistått i fältförsökets genomförande. Ett stort tack riktas också till Stiftelsen Backamo Lägerplats som upplåtit det aktuella fallstudieområdet.Projektet som presenteras i denna rapport har varit nära knutet till andra pågående projekt vid Chalmers som behandlar mikrobiella risker och grundvattenfrågor, men då med fokus på kommunala grundvattentäkter. Författarna är mycket tacksamma för finansieringen från Havs- och vattenmyndigheten, vilket möjliggjort detta projekt och därmed också en fortsatt utveckling inom området. Förhoppningen är att den utvecklade MRA-modellen, trots kvarstående förbättringsmöjligheter, ska komma till praktisk nytta och underlätta bedömningen av den hälsorisk enskilda avlopp kan utgöra.
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| 39. |
- Lundin Frisk, Emrik, 1994, et al.
(författare)
-
The geosystem services concept – What is it and can it support subsurface planning?
- 2022
-
Ingår i: Ecosystem Services. - : Elsevier BV. - 2212-0416. ; 58
-
Forskningsöversikt (refereegranskat)abstract
- The subsurface is a multifunctional natural resource. However, a mindset of “out of sight, out of mind” and a first-come-first-served principle are prevalent when accessing these resources, compromising fair intergenerational and intragenerational distribution and sustainable development. As with the ecosystem services (ES) concept, which acknowledges the contribution of the living part of nature to human well-being, the concept of geosystem services (GS) has been suggested as a way to highlight abiotic services and services provided by the subsurface. The overall aim of this study was to review current definitions of GS and their categorisation, and to suggest how the concept of GS can support subsurface planning. A systematic literature review on GS was carried out following the PRISMA protocol drawing from the Scopus database. The emerging picture from the reviewed articles is that the GS concept is both one of novelty and one currently showing inconsistency, with two prominent definitions: A) GS are abiotic services that are the direct result of the planet's geodiversity, independent of the interactions with biotic nature – there is no differentiation between suprasurface and subsurface features, and B) GS provide benefits specifically resulting from the subsurface. Thirty-one out of thirty-nine GS listed in the reviewed literature are included in the abiotic extension of the common ES framework CICES v5.1, but some essential services are omitted. A unified definition of GS is desirable to build a common framework for classifying and describing GS, potentially following the CICES structure for ES. Such a framework can support systematic inclusion of GS in planning processes and contribute to improved subsurface planning. In planning practice, there are examples of important GS that are already included under the ES umbrella because planners are aware of their importance but a comprehensive framework to handle these services is lacking.
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| 40. |
- Norberg, Tommy, 1950, et al.
(författare)
-
Added value in fault tree analyses
- 2009
-
Ingår i: Safety, Reliability and Risk Analysis: Theory, Methods and Applications. Joint ESREL (European Safety and Reliability) and SRA-Europe (Society for Risk Analysis Europe) Conference; Valencia; Spain; 22-25 September 2008. - : CRC Press. - 9780415485135
-
Konferensbidrag (refereegranskat)abstract
- It is recognized that the usual output of a fault tree analysis in some studies is not sufficiently informative. For added value in a widely used instrument for doing risk analyses, a Markovian approach is suggested. It is shown how to extend the calculations of the standard fault tree gates, so that information is available not only on the failure probability at the top level, but also on estimates of its rate of failure and mean down time. In applying this to an integrated fault tree analysis of a municipal drinking water system, we further identified the need for gates that are variations of those currently in use.
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| 41. |
- Norberg, Tommy, 1950, et al.
(författare)
-
Added value in fault tree analysis
- 2008
-
Ingår i: In Safety, Reliability and Risk Analysis: Theory, Methods and Applications. Martorell et al. (eds), pp 1041-1048, Taylor & Francis Group, London 2008. ; 2, s. 1041-1048
-
Konferensbidrag (refereegranskat)
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| 42. |
- Ohlin Saletti, Anna, 1989, et al.
(författare)
-
Cost to society from infiltration and inflow to wastewater systems
- 2023
-
Ingår i: Water Research. - : Elsevier BV. - 0043-1354 .- 1879-2448. ; 229
-
Tidskriftsartikel (refereegranskat)abstract
- Water from infiltration and inflow to wastewater systems is an extensive problem causing costs to society in various ways. Comprehensive methods for supporting decisions on how to efficiently mitigate the problems in a sustainable manner are, however, missing today. This paper presents a novel risk-based model to assess the cost to society from infiltration and inflow to wastewater systems by monetising effects related to treatment of wastewater, pumping, combined sewer overflows, and basement flooding. The present value is calculated for a specified time horizon and discount rate, using a cost-benefit analysis approach. To acknowledge the various uncertainties, a probabilistic approach is applied where probability distributions represent the input variables. The model is shown to be applicable by illustrating its use in a case study area in Gothenburg, Sweden. Main results from the case study show that most of the costs are related to investments at the wastewater treatment plant and restoration due to basement flooding events. Sensitivity analyses show that the result is highly dependent on factors such as the volume of infiltration and inflow water, the share of basement flooding, and the discount rate. Using expert elicitation to quantify input data is also illustrated and shown to be a valuable method. The presented model fills an important research knowledge gap and will facilitate a more sustainable and comprehensive handling of water from infiltration and inflow.
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| 43. |
- Ohlin Saletti, Anna, 1989, et al.
(författare)
-
Framework for Risk-Based Decision Support on Infiltration and Inflow to Wastewater Systems
- 2021
-
Ingår i: Water (Switzerland). - : MDPI AG. - 2073-4441 .- 2073-4441. ; 13:17
-
Tidskriftsartikel (refereegranskat)abstract
- Infiltration and inflow (I/I) to wastewater systems cause e.g., flooding, pollution, and the unnecessary use of the limited resources in society. Due to climate change and an increased need for the renewal of piping systems, making the right decisions on how to handle I/I is more important than ever. This paper presents a novel framework for risk-based decision support on I/I based on established theories on risk assessment and decision-making. The framework is presented on a general level and suggests that uncertainties are included in the decision-making process, together with criteria representing the economic, social, and environmental dimensions of sustainability. Published models on I/I and decision support are evaluated based on criteria from the framework showing that (1) the models rarely include risk-based decision-making or uncertainties in the analyses and that (2) most models only include project-internal financial aspects, excluding social and environmental, as well as project-external aspects, of I/I and I/I measures. A need for further research to develop a more holistic decision support model for I/I is identified, and it is concluded that the application of the proposed framework can contribute to more sustainable decisions on how to handle I/I and provide transparency to the process.
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| 44. |
- Rosen, Lars, 1962, et al.
(författare)
-
Comparing Raw Water Options to Reach Water Safety Targets Using an Integrated Fault Tree Model
- 2008
-
Ingår i: International Water Association Conference, Water Safety Plans: Global Experiences and Future Trends, Lisbon, Portugal, 12-14 May, 2008.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In the 3rd edition of the Guidelines for Drinking-water Quality, the World Health Organization (WHO) concludes that an integrated management of risks in source waters, treatment systems and distribution networks is the most effective way to guarantee safe drinking water to consumers. The integrated approach is fundamental to avoid sub-optimisation of risk reduction efforts. This paper presents an application of an integrated and quantitative risk model for comparing risk-reduction alternatives to support decisions for reaching specified water safety targets. A fault tree approach is used for structuring the risk analysis and for estimating the risk, expressed as Costumer Minutes Lost. Input information is a combination of hard data and expert judgements. Uncertainties in input information are considerable and modelled by a Bayesian statistical approach. The Göteborg drinking water system is used to exemplify model application. Quantitative safety targets have been confirmed at the political level as a basis for long-term planning of investments and reinvestments. Four different risk reduction alternatives were compared and increased treatment capacity in combination with additional raw water supply was shown to provide the greatest risk reduction. The paper describes how a structured and thorough analysis of risk reduction options can facilitate transparency and long-term planning of drinking water systems.
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| 45. |
- Rosen, Lars, 1962, et al.
(författare)
-
Comparing risk-reduction measures to reach water safety targets using an integrated fault tree model
- 2010
-
Ingår i: Water Science and Technology: Water Supply. - : IWA Publishing. - 1606-9749. ; 10:3, s. 428-436
-
Tidskriftsartikel (refereegranskat)abstract
- In the third edition of the Guidelines for Drinking-water Quality, the World Health Organization concludes that an integrated management of risks in source waters, treatment systems and distribution networks is the most effective way to guarantee safe drinking water to consumers. The integrated approach is fundamental to avoid sub-optimisation of risk-reduction measures. This paper presents an application of an integrated and quantitative risk model for comparing risk-reduction measures to support decisions for reaching specified water safety targets. A fault tree approach is used for structuring the risk analysis and for estimating the risk, expressed as Customer Minutes Lost (CML). Input information is a combination of hard data and expert judgements. Uncertainties in input information are considerable and modelled by a Bayesianstatistical approach. A drinking water system in Sweden is used to exemplify model application. Quantitative safety targets have been confirmed at the political level as a basis for long-term planning of investments and reinvestments. One target defines an acceptable risk level of 144 annual CML for the average consumer. For the current system structure an estimated risk of 612CML was obtained. Four risk-reduction alternatives were compared and they reduce the risk to between 50 and 81 CML, i.e. below the acceptable level. The paper describes how a structuredand thorough analysis of risk-reduction measures can facilitate transparency and long-term planning of drinking water systems.
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| 46. |
|
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| 47. |
- Rosen, Lars, 1962, et al.
(författare)
-
Generic Framework for Integrated Risk Management in Water Safety Plans
- 2008
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the Guidelines for Drinking-water Quality, the World Health Organisation (WHO) concludes that end-product testing is not sufficient to guarantee safe drinking water to consumers. Such analyses are often completed after the water is consumed and they may not provide correct information regarding the health effects of the water. Instead, WHO recommends preparation of risk-based Water Safety Plans (WSP) from ‘source to tap’, which considers conditions in source waters, treatment systems and distribution networks. WSP is currently being implemented in several countries and is expected to become increasingly important for water management in both developed and developing countries. WSPs facilitate an increase in awareness and understanding of risk issues fundamental for providing safe drinking water. WHO provides general but not detailed information on risk assessment and risk management procedures in WSPs. The primary purpose of this paper is to describe a framework for a structured risk management in WSPs. The framework is currently being developed within the European Commission Sixth Framework Programme project TECHNEAU (Technology Enabled Universal Access to Safe Water). The suggested framework cannot provide one single risk management method applicable to all types of water utilities. Instead, the framework will provide: (1) principles for good risk management practice; (2) a relevant set of tools; and (3) clear examples. This paper includes: (1) a short review and presentation of WSP; (2) a presentation of the current version of the TECHNEAU Generic Framework for Integrated Risk Management in WSP; and (3) a short description of some risk analysis methods currently being developed in the project.
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| 48. |
- Sjöstrand, Karin, 1975, et al.
(författare)
-
Cost-Benefit Analysis for Supporting Intermunicipal Decisions on Drinking Water Supply
- 2019
-
Ingår i: Journal of Water Resources Planning and Management - ASCE. - 0733-9496 .- 1943-5452. ; 145:12
-
Tidskriftsartikel (refereegranskat)abstract
- Several countries promote a regionalization of the drinking water sector; however, few decision support tools are adapted to the intermunicipal level to aid in regional decisions. The aim of this paper is to describe and demonstrate a probabilistic cost-benefit analysis approach to assess the societal effects of regional water supply interventions to constitute support for decision makers. A special focus is given to the quantification of effects on consumers’ health, water supply reliability, and operation and maintenance costs. The uncertainties of the quantified values are represented by probability distribution functions and analyzed by means of Monte Carlo simulations. The proposed approach was demonstrated in the Göteborg region in Sweden, for which five alternative interventions were evaluated. In conclusion, the proposed approach facilitates the identification and prioritization of societal effects so that costs and benefits normally overlooked in evaluation processes can be explicitly considered and addressed. The paper provides a transparent handling of uncertainties and enables a structured approach to improve decision makers’ ability in making informed choices on regional water supply alternatives.
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| 49. |
- Sjöstrand, Karin, 1975, et al.
(författare)
-
Input data report for economic assessments of water supply interventions in the Göteborg region
- 2018
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report is part of a research project funded by the Swedish Research Council Formas with support from RISE Research Institutes of Sweden, The Göteborg Region Association of Local Authorities (GR) and the City of Göteborg. The study was performed at the centre for drinking water research (DRICKS). The research project aims to develop a decision support model for sustainability assessments of regional water supply interventions and cooperations based on a combination of multi-criteria decision analysis (MCDA) and cost-benefit analysis (CBA). This report focuses on the CBA part of the model. In the process of developing the model, five alternative water supply interventions for the Göteborg region were evaluated. By applying the decision model to alternatives focusing on establishing inter-municipal organizations, (de)centralization of water production, as well as source water quality and redundancy aspects, the model was tested for some common decision situations in the water supply sector. The application in the Göteborg region was a way to develop the model, and at the same time demonstrate and evaluate its feasibility. This report presents input parameters of the CBA for the alternative interventions. For the Göteborg region, it was found that the alternative which comprised a regionalized governance and maintained semi-decentralized production had the highest probability of being the most profitable solution, whereas the alternative which comprised maintained governance with additional source waters and treatment plants had the second highest probability of being the best solution.
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| 50. |
- Sjöstrand, Karin, 1975, et al.
(författare)
-
Marginal Abatement Cost Curves for Water Scarcity Mitigation under Uncertainty
- 2019
-
Ingår i: Water Resources Management. - : Springer Science and Business Media LLC. - 0920-4741 .- 1573-1650. ; 33:12, s. 4335-4349
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Tidskriftsartikel (refereegranskat)abstract
- As water scarcity and drought become more common, planning to avoid their consequences becomes crucial. Measures to prevent the impact of new climate conditions are expected to be extensive, costly and associated with major uncertainties. It is therefore necessary that policymakers and practitioners in both the public and private sector can compare possible mitigation measures in order to make economically rational investment decisions. For this to be successful, decision-makers need relevant decision support. This paper presents a novel approach of constructing marginal abatement cost curves for comparing water scarcity mitigation measures while taking the underlying uncertainties into account. Uncertainties in input variables are represented by probability distributions and calculations are performed using Monte Carlo simulations. This approach is applied on the island of Gotland, one of the most water-stressed parts of Sweden, to provide the first marginal abatement cost curve in Europe for water scarcity mitigation in which municipal, agricultural, industrial and household measures are compared. The results show that the agricultural measure of on-farm storage has the greatest potential to increase water availability on the island. Among municipal measures, increased groundwater extraction and desalination offer the greatest potential, although desalination is almost 25 times more costly per cubic meter. The most cost-effective measure is linked to hot water savings in the hotel industry. The approach presented provides a quantitative visualization of the financial trade-offs and uncertainties implied by different mitigation measures. It provides critical economic insights for all parties concerned and is thus an important basis for decision-making.
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