ACTeon
Innovation, policy, environment
BRIDGE
“Background cRiteria for the IDentification of Groundwater thrEsholds”
Specific targeted Research Project Scientific Support to Policies (SSP)
Contract n° SSPI-2004-006538 Start date of the project: 1 January 2005
Duration: 24 month
D42: Assessing socio-economic impacts of different groundwater protection regimes
Slovenian case study report November 2006
The deliverable authors are responsible for the content
AUTHOR: Pierre Strosser and Hélène Bouscasse AFFILIATION: ACTeon
ADDRESS: Le Chalimont B.P. Ferme du Pré du Bois 68370 Orbey – France TEL.: +33 3 89 47 39 41
EMAIL: Pierre.strosser@wanadoo.fr
Project co-funded by the European Commission within the Sixth Framework Program (2002-2006) Dissemination Level
PU Public
PP Restricted to other program participants (including the Commission Services) X RE Restricted to a group specified by the consortium (including the Commission Services)
CO Confidential, only for members of the consortium (including the Commission Services)
Table of Content
Table of Content ... 2
Acknowledgments... 3
Acronyms ... 4
Executive summary... 5
1. Introduction... 6
2. Methodological framework ... 8
2.1 The role of socio-economics in the WFD ... 8
2.2 General steps for socio-economic assessment procedure... 9
3. Which water management issues in the Krska kotlina aquifer? ... 12
3.1 Main characteristics of the aquifer ... 12
3.2 Main groundwater pollution issues... 12
3.3 Groundwater abstraction... 14
4. Designing the programme of measures for reducing pollution from petroleum products in shallow groundwater... 16
4.1 Socio-economic assessment of different water quality objectives... 16
4.2 Detailed characterization of measures, their effects and costs ... 16
4.3 Developing alternative programs of measures (scenarios) ... 19
4.4 Assessing costs of alternative scenarios ... 20
5. Public perception of shallow groundwater pollution: methodology and results of the survey ... 22
5.1 Organising the survey ... 22
5.1.1 Building the questionnaire... 22
5.1.2 Defining the scenarios... 23
5.1.3 Elicitation format... 24
5.1.4 Pre-testing... 24
5.1.5 Sampling procedure ... 25
5.1.6 Practical organization of the survey ... 25
5.2 Analysis of the survey data: descriptive statistics... 25
5.3 Investigating specific methodological assumptions ... 29
5.4 Identifying factors influencing willingness to pay: results from regression analyses ... 31
5.5 Lessons from the contingent valuation survey... 39
6. Undertaking the cost-benefit analysis for restoration programmes for shallow groundwater 42 6.1 Assessing benefits of alternative scenarios ... 42
6.2 Assessing the impact of groundwater quality improvements on abstractors... 43
6.3 Identifying the most economically efficient water quality objective... 44
7. Conclusions ... 46
Bibliography... 47
Acknowledgments
The Slovenian case study of the project entitled “Background cRiteria for the IDentification of Groundwater thrEsholds” (BRIDGE), funded by the EC under the 6th framework program, has been developed by contributing to activities of a parallel EU-funded (PHARE funding) project entitled Technical Assistance for the preparation of the Krka river basin management plan located in the Krka sub-basin and managed by Hidroinženiring d.o.o. (Slovenia), with Ecorys (the Netherlands) and IEI d.o.o. (Slovenia) as partners.
Thus, the authors of this report would like to thank experts from this technical assistance project in particular Leo Beumer, Neža Eržen, Anita Gole and Urska Hozjan who were involved in economic assessments and in the contingent valuation survey. The authors would also like to thank Joerg Prestor from the Geological Survey who participated in this groundwater case study and provided continuous support to the study.
The authors of this BRIDGE case study report, however, retain full responsibility for its content, results and messages.
Acronyms
CBA Cost Benefit Analysis
CEA Cost Effectiveness Analysis CV Contingent Valuation
GW Groundwater
GWB Groundwater body GWD Groundwater Directive
WATECO European Water and Economics Working Group
WB Water Body
WFD Water Framework Directive WTP Willingness-To-Pay
Executive summary
As part of the activities developed under WP5 of the EU-funded BRIDGE research project, a case study has been developed to assess the socio-economic implications of different water quality objectives for groundwater in Slovenia. This case study was made possible by providing additional (human) resources to existing activities undertaken in the context of the Krka Pilot Project that aimed at testing methods and tools for supporting the implementation of the WFD in Slovenia. These additional resources helped strengthening the development of a groundwater case study implemented by the Krka Pilot project team and the Geological Survey of Slovenia.
An economic analysis was developed for the Krska kotlina aquifer, a small aquifer located close to the boarder with Croatia and under pressure from nitrate and pesticide pollution.
Different groundwater quality improvements have been proposed for improving the aquifer up to drinking water level or for restoring close to background level concentrations/natural conditions. The economic implications of these different groundwater quality improvement scenarios were investigated both in terms of costs and benefits.
Overall, the economic analysis stresses that estimated costs are higher than benefits for most water quality improvement scenarios. This can be explained by the limited use of the aquifer today (and in the future). The low population density in the area also explains limited benefits. The analysis stresses once more the importance of aggregation – as the final evaluation of total benefits based on values obtained from a contingent valuation survey carried out in the area are clearly dependent on the population to which values are applied.
The contingent valuation survey carried out as part of this activity produced first results in terms of people’s willingness to pay for groundwater improvement programmes for the Krska kotlina aquifer. Overall, 63% of the total sample is willing to pay for groundwater improvement programmes aimed at stabilising groundwater quality below drinking water threshold values with an average value of 1 350 SIT per household per month. But only 40%
of the total sample is willing to pay for more ambitious improvement programmes aimed at bringing groundwater quality close to natural concentrations and thus eliminating any possible risk to connected ecosystems. The additional contribution for this second programme is equal to 1 150 SIT per household per month on average. These values are around 15% to 20% of household’s average monthly water bill.
The main lesson from the regression analyses is that location has an important impact on people’s willingness to pay and on the contribution to groundwater improvement programmes. The total mean value for households living on top of the aquifer is 2 591 SIT while other households state an amount of 1 688 SIT on average. Trust in the programme is also a key factor influencing people’s willingness to pay. Belonging to an environmental organization or citing the preservation of the patrimony as the main motivation to pay show interest for environmental matters. This interest is expressed through higher contributions to groundwater improvement programmes. However, contribution is not only a matter of interest, location and trust. It also depends on people’s incomes. Low income groups will contribute with smaller amounts to the first groundwater improvement scenario and will be less willing to pay for both scenarios.
1. Introduction
Aquatic ecosystems are adaptive, but ecologically sensitive systems, which provide many important services to human society. This explains why in recent years much attention has been directed towards the formulation and operation of sustainable management strategies, the recent adoption of the European Water Framework Directive (2000/60/EC) being a good case in point. Both natural and social sciences can contribute to an increased understanding of relevant processes and problems associated with such strategies. The key to a better understanding of aquatic ecosystem problems and their mitigation through more sustainable management, lies in the recognition of the importance of the diversity of functions and values supplied to society at different spatial and time scales. This includes a better scientific understanding of aquatic ecosystem structure and processes and the significance of the associated socio-economic and cultural values.
The Water Framework Directive (WFD) is the first European Directive that explicitly recognizes the importance of this interdependency between aquatic ecosystems and their socio-economic values and provides a much more integrated catchment approach to water policy. Investments and water resource allocations in river basin management plans will be guided by cost recovery, cost-effectiveness criteria and the polluter pays principle. The plan formulation and assessment process must furthermore include a meaningful consultative dialogue with relevant stakeholders. Such a dialogue will inevitably raise socio-political equity issues across the range of interest groups and therefore affect the management strategies.
Although groundwater resources are an integral part of catchment wide aquatic ecosystems, their position and role are not well defined in the WFD. No new quality standards were listed that apply uniformly to all groundwater bodies throughout Europe to define good groundwater chemical status, because of the natural variability of groundwater chemical composition and the present lack of monitoring data and knowledge. Article 17 stipulates that the European Parliament and the Council shall adopt specific measures to prevent and control groundwater pollution on the basis of a proposal for a new Groundwater Directive. The new Groundwater Directive (GWD) complements the provisions already in place in the WFD and in the existing Groundwater Directive 80/68/EEC, which will be repealed in 2013 under the WFD.
In its communication COM(2003)550, the European Commission states that groundwater bodies shall be considered as having good groundwater chemical status when the measured or predicted concentration of nitrates, pesticides and biocides do not exceed standards laid down in existing legislation (Directives 91/676/EEC, 91/414/EEC and 98/8/EC respectively).
For other pollutants good groundwater chemical status is reached when it can be demonstrated that the concentrations of substances do not undermine the achievement of the environmental objectives (good ecological and chemical status) for associated surface waters or result in any significant deterioration of the ecological or chemical status of these surface water bodies, nor should concentrations result in any significant damage to terrestrial ecosystems which depend directly on the groundwater body. For these other pollutants, groundwater quality threshold values have to be established by Member States in all bodies of groundwater that were characterized in the recent first WFD reporting obligations as being
“at risk”.
In order to support this process of determining future groundwater quality threshold values for European groundwater bodies, the Environment Directorate-General of the European Commission commissioned a 2-year project to develop a general methodology for establishing groundwater threshold values called BRIDGE (Background cRiteria for the IDentification of Groundwater thresholds, contract n° SSPI-2004-006538). The methodology has to apply to substances from both natural and anthropogenic sources and threshold values defined at the level of national river basin districts or groundwater body levels should be representative for the groundwater bodies “at risk” in accordance with the analysis of pressures and impacts carried out under the WFD. In the proposal for the new Groundwater Directive these threshold values will be used for defining good groundwater chemical status.
As part of BRIDGE, a socio-economic assessment is carried out in support of setting threshold values for specific groundwater pollutants and for the evaluation of the social and economic consequences of specific threshold values. The assessment procedure follows the economic analysis outlined in the WFD and more specifically in the WATECO guidance for the economic analysis. Based on a common methodology (Brouwer, 2005), it was proposed to test and illustrate the socio-economic assessment procedure in a number of practical case studies in France, Finland, Latvia, the Netherlands and Portugal.
As one of the partners of WP5, ACTeon, was also involved in WFD-related activities in Slovenia, the possibility to develop an additional case study for this country was proposed.
The case study was eventually developed by providing additional (human) resources to existing activities undertaken in the context of the Krka Pilot Project (a EU/PHARE-funded project aimed at testing methods and tools for supporting the implementation of the WFD in Slovenia) under which collaborative activities with the Geological Survey of Slovenia were developed. This made possible, in particular, the development of a full scale contingent valuation survey, an effort not originally foreseen in the Krka Pilot project or in the BRIDGE project but that proved very relevant and valuable.
The main objective of this report is to present the results of the socio-economic assessment procedure applied to the Krsko kotlina aquifer in Slovenia (the so-called Slovenian case study) – building on the experience and report developed in the context of the Krka Pilot project. It builds in particular on the following reports of the Krka Pilot project team:
• Krka Pilot Project. 2006a. Characterisation of the Krka River sub basin. Technical report of the Krka Pilot Project, Ljubljana.
• Krka Pilot Project. 2006b. Selecting measures to improve water status in the Krka River sub-basin. Technical report of the Krka Pilot Project, Ljubljana.
• Krka Pilot Project. 2006c. Application of environmental cost valuation methods in the Krka River sub-basin. Technical report of the Krka Pilot Project, Ljubljana.
• Krka Pilot Project. 2006d. Cost benefit analysis for a groundwater case study in the Krka River sub-basin. Technical report of the Krka Pilot Project, Ljubljana.
The content of the report is organized as follows.
• Chapter 2 briefly presents the methodological framework applied to all BRIDGE case studies;
• Chapter 3 characterizes the groundwater body selected for the case study, i.e. the Krska kotlina aquifer located at the border with Croatia in the downstream part of the Krka River sub-basin. It presents the main pressures on the aquifer and impacts in terms of groundwater pollution. It compares groundwater quality with water quality objectives set in legislation, stressing that these objectives will not be met;
• Chapter 4 investigates potential measures for reaching proposed objectives. It develops different programmes of measures (scenarios) for reaching different water quality objectives, calculating the total costs of these programme/scenarios;
• Chapter 5 analyses people’s perception vis-à-vis groundwater quality and restoration programmes – investigating people’s willingness to pay for programmes that would restore and improve the groundwater quality of the Krska kotlina aquifer;
• Chapter 6 presents the results of the economic assessment of the water quality objectives and related programmes of measures, comparing in particular their total costs and benefits;
• Chapter 7 presents some conclusions linked to results of the economic analysis and to methodological steps followed in the case study, in particular with regards to the valuation of environmental benefits from groundwater quality improvement obtained using the contingent valuation method.
2. Methodological framework
One of the general objectives of the socio-economic assessments carried out as part of the BRIDGE project is to support discussion on what role economics should play in the process of setting threshold values. This section of the report first of all characterizes the role of economics considered by the WFD. The steps of economic analysis envisaged by the WFD formed basis for the general methodology of socio-economic assessments as part of the BRIDGE, which is presented afterwards in this section. The section ends with describing how this general methodology has been applied in the Latvian case study.
2.1 The role of socio-economics in the WFD
The WFD is one of the first European Directives in the domain of water, which explicitly recognizes the role of economics in reaching environmental and ecological objectives. The Directive calls for the application of economic principles (e.g. polluter pays principle), approaches and tools (e.g. cost-effectiveness analysis) and for the consideration of economic instruments (e.g. water pricing policies) for achieving good water status for water bodies in the most effective manner. The Guidance Document on the Economic Analysis prepared in 2002 by the European Water and Economics Working Group (WATECO) advises various elements of the economic analysis to be integrated in the policy and management cycle in order to aid decision-making when preparing the River Basin Management Plans. The integration of economics throughout the WFD policy and decision- making cycle is presented in the figure 1.
Source: WATECO Guidance Document
Figure 1. The role of economics throughout the WFD implementation process
The main elements of the economic analysis are found in Articles 5 and 9 and Annex III in the WFD. Economic arguments also play an important role in the political decision-making process surrounding the preparation of River Basin Management Plans (in Article 4) where derogation can be supported by the strength of economic arguments when setting environmental objectives. The economic analysis can be summarised as follows:
1) Economic characterisation of a river basin (Article 5)
• Assessment of the economic significance of water use in a river basin.
• Forecast of supply and demand of water in the river basin up to 2015.
• Assessment of the current cost recovery by estimating the volume, prices, investments and costs associated with water services, including environmental and resource costs.
2) Cost-effectiveness analysis (Article 11 and Annex III)
• Evaluation of the costs and effectiveness of the proposed programme of measures to reach environmental objectives.
3) Disproportional costs (Article 4)
• Evaluation whether the costs are disproportionate.
4) Cost recovery and incentive pricing (Article 9)
• Assessment of the distribution of costs and benefits and the potential impact on cost recovery and incentive pricing.
The first step, the economic characterisation of river basins, has been completed in 2005.
The last two years (2005-2006) the preliminary risk analysis, which had been carried out for the different European river basins, was further elaborated (including the more detailed definition of environmental objectives) and start will be made with the identification of additional measures needed to reach good water status in the second step.
By the end of 2007 each EU Member State has to produce an overview of its basic and additional measures according to Article 11, from which the most cost-effective programme of measures will be developed by the end of 2008. Based on the cost-effectiveness analysis of programmes of measures, the question whether the total costs of additional measures to reach good water status are disproportionate will be addressed by the end of 2009. Finally, the financial implications of the basic and additional measures for different groups in society has to be evaluated by 2010, including the level of cost recovery, changes in the use and efficiency of economic instruments (e.g. levies, taxes, water prices) and their role in achieving a more efficient and sustainable water use.
2.2 General steps for socio-economic assessment procedure
In the common methodological framework for the socio-economic assessment procedure in BRIDGE, the steps of the economic analysis in the WFD presented in the previous sub- section have been translated in the following practical steps:
1) Socio-economic analysis of the current and future groundwater use and corresponding pressures and impacts
2) Risk and uncertainty analysis of non-compliance (“gap analysis”) 3) Identification of possible measures
4) Estimation of costs and effectiveness of possible measures to bridge the gap in cost- effectiveness analysis (least cost way to achieve quality objective)
5) Assessment of benefits of meeting quality objective and comparing them with the costs.
These steps are visualized in the figure 2 below. They are taken iteratively but can include various feedbacks to the previous levels of analysis and evaluation.
The main objective of the first step is to describe and analyse current groundwater use patterns and the pressures exerted by key socio-economic sectors, possibly resulting in non- compliance with water quality objectives. Related to this is the prediction of expected future pressures and impacts on groundwater chemical status from socio-economic driving forces.
The future socio-economic trends are estimated and translated in terms of expected future pressures and impacts on groundwater quality.
Current groundwater body status
Socio-economic developments
Consequent pressures on groundwater
body
Required groundwater body status in 2015
Setting groundwater quality objectives:
• Establishing threshold values
• Choosing compliance regime or decision criteria for compliance assessment
Expected groundwater body status in 2015
Arti cl e 4 and 5
Problem identification: gap between expected and desired groundwater body status
Identification possible measures
Comparison of costs and benefits Selection cost-effective measures
Article 1 1 a nd 17
Figure 2. Contribution of socio-economic analysis into the process of setting groundwater threshold values and achieving good chemical groundwater status (in relation to the relevant articles in the WFD)
In the second step, the current and future pressures from socio-economic driving forces and their expected impact on groundwater chemical status are compared with possible groundwater quality objectives. The main aims of the second step are to identify (i) the gap between expected groundwater quality (in the 2015) and the quality objective and (ii) the key factors determining this gap and the uncertainty surrounding these factors.
To conduct this step, a quality objective has to be defined that requires threshold values to be established. It is expected that threshold values used for the gap analysis are set based on purely environmental considerations. However, as indicated by the analysis presented in this report, the economics could already play a role for defining quality objectives at this stage of the analysis.
Once the gap has been assessed (in a qualitative or quantitative way depending on available data and information), measures to meet the established groundwater quality threshold
values can be proposed in Step 3. Possible measures to prevent and abate groundwater contamination need to be listed and assessed in terms of costs and effects. For each potential measure, direct financial costs and, where possible, indirect economic costs have to be estimated. Besides costs, direct and indirect effects of measures on groundwater chemical status have to be assessed. Based on this information, the least costly way to reach proposed threshold values can be estimated. In this way, the socio-economic analysis can also provide input in the process of setting groundwater threshold values – based on the assessment of the least costly way to reach groundwater threshold values.
If it is felt that proposed measures for reaching the established threshold value might be disproportionately expensive, a cost-benefit analysis has to be carried out. Water quality improvements (originating from reaching desired threshold values) may result in significant socio-economic benefits. And the aim of the last (5th) step of the analysis is to estimate whether these benefits exceed costs or not. In the latter case, possible time or objective exemptions might be justified. Thus, the socio-economic analysis underpins the justification of exemptions for setting socio-economically efficient and acceptable groundwater quality threshold values.
3. Which water management issues in the Krska kotlina aquifer?
3.1 Main characteristics of the aquifer
The Krska kotlina aquifer covers an area of around 90 km2 located at the downstream portion of the Krka River sub-basin near the boarder with Croatia. It is composed of around 20 meters of quaternary sediments (the most important from a water point of view and highly permeable), of Pliocene sediments (between 0 and 600 meters of thickness) and of Miocene sediments with very low permeability. Rainfall in the area ranges from 900 to 1200 mm per year on average. And evapo-transpiration is estimated at 700 mm per year. The boundaries of the groundwater body (see Figure 3) do not coincide with administrative or surface water catchment boundaries. Indeed, the groundwater body area is shared between two municipalities (Krsko and Brezice) and between the catchment areas of the Krka River and of the Sava main river.
The aquifer is mainly recharged from precipitation, and to a much lower extent from the Sava River (average flow of 290 m3/s), the Krka River (average flow of 55 m3/s) and from small creeks. The groundwater body is connected to surface water, in particular wetlands along the Krka River, although little is known about the importance of this connection and how it affects the quality of the Krka River (if at all). The groundwater body also feeds into the most downstream part of the Sava river itself – the aquifer contributing to river flows during low flow periods.
Figure 3. Hydrological boundaries of the Krska kotlina aquifer (source: Krka Pilot project, 2006c)
3.2 Main groundwater pollution issues
The Krska kotlina aquifer is under pressures from different economic sectors and users.
Overall, the aquifer is under pressure from different sources of pollution in particular: (i) leakages from sewerage systems, (ii) inadequate sewage for dispersed settlements and malfunctioning sceptic tanks of individual households, (iii) leakages from landfills, (iv) inadequate management of farm yard manure, and finally and more importantly (v) high use of pesticides and fertilisers in agriculture. As a result of these pressures:
• Nitrate concentrations in the aquifer are currently increasing. Average concentrations are today just below the starting point for trend reversal of 37.5 mg/l (see Figure 4).
And if no additional action is taken1, water from the Krsko aquifer will become non- drinkable in the medium term with its concentration expected to reach 60 mg/l in the long-term (thus well-above the drinking water threshold of 50 mg/l – see Figure 5);
• Pesticides are also found in most parts of the aquifer, e.g. at all monitoring sites of the aquifer. Average pesticide concentrations remain low so groundwater is still drinkable. But concentrations of some pesticides (e.g. desetilatrazin and symazine) are increasing. Today, values higher than the threshold value of 0.1 µg/l are already found for desetilatrazine in the Drnovo abstraction well supplying water to the municipality of Krsko.
Some of the pollution of the aquifer might be transferred to natural areas and connected ecosystems which balance could then be threatened. However, there is much uncertainty on these interconnections and on the risk for connected ecosystems originating from groundwater pollution.
VTPodV KRŠKA KOTLINA: Nitrati
0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00
1997 1998 1999 2000 2001 2002 2003 2004 2005
nitrati (mg/l)
Figure 4. Trends in average nitrate concentration for the Krsko kotlina aquifer (source: Krka Pilot Project, 2006a)
Figure 5. Expected future trend in nitrate concentration for the Krsko kotlina aquifer (source:
Krka Pilot Project, 2006d)
1 It is assumed that economic development and changes in the agriculture sector will be nitrate pollution neutral.
3.3 Groundwater abstraction
Groundwater from the Krsko kotlina aquifer is abstracted for municipal water use, industrial processes and agriculture use (irrigation).
With regards to municipal water abstraction and household water use, there are two wells supplying water to the municipality of Krško and abstracting groundwater from the Krska kotlina aquifer, namely the Drnovo well supplying water to the right river bank and the Brege well supplying water to the left river bank. The Drnovo well has a capacity of 50 l/s and it is supplying on average 35 l/s. The Brege well has a higher capacity of 60 l/s, but it is only supplying 25 l/s on average.
The Krško municipal water supply system also use water from other wells that are pumping water from other (shallow) aquifers and not from Krska kotlina. The same applies for the municipality of Brežice that only relies on wells pumping water from other nearby shallow aquifers.
The area above the Krska kotlina aquifer hosts several settlements as indicated in Figure 3.
However, many of their inhabitants are connected to drinking water supply networks which use other sources of water than the Krska kotlina aquifer. In total, 4 677 inhabitant are connected to the Drnovo and Brege wells abstracting water from the aquifer. This represents a total water use of around 388 000 m3 per year (2005 figures, see Krka Pilot Project, 2006d). In addition, many inhabitants still have their own wells (see Chapter 5), although water abstracted from these wells is always used in complement to water from the municipal network.
Groundwater abstraction for industrial water use is rather limited in the area that is mainly rural. Six wells, located in the municipality of Krško, abstract water from the aquifer mainly for small industries (paper and cellulose, construction…) and for the Krško Nuclear Power Plant (for drinking and cleaning – not for cooling). And this limited abstraction will not evolve drastically in the coming years as no significant industrial development is foreseen in the area.
In the area of the municipality of Brežice, there are four wells abstracting water from the aquifer used by Čatež Spa, a well-known spa center. Two of these wells are thermal wells pumping water at a depth of 564 and 532 m – thus not in the Krska kotlina aquifer. The two other wells are pumping water from the aquifer for drinking water purposes (for visitors and tourists).The average capacity of these wells is 7 l/s. And total yearly water use has been estimated at 220 000 m3 (Krka Pilot project, 2006d).
Abstraction for agriculture is made by two main wells used to irrigate vegetables (tomato, gherkin, paprika, lettuce…) and fruits (strawberries and apples). There are two other wells that are currently not operated and kept as “reserve” – and also a large number of small (illegal) wells. Overall, direct abstraction from the aquifer remains very limited as farmers are mainly abstracting water from the Sava River, the Krka River and from gravel pits.
Overall, the degradation of the quality of the aquifer because of increasing nitrate and pesticide pollution will not affect industrial water use and agriculture water use (irrigation).It will however become very problematic for municipal water use (water abstracted from the Drnovo and Brege wells) and for the thermal center of Čatež Spa as soon as pollutant concentrations are higher than set water quality standards.
As groundwater quality deteriorates, specific investments will be required by the municipalities and by the thermal center to ensure the water they supply to customers and visitors has good drinking water quality.
• Alternative solutions for ensuring good quality drinking water for the inhabitants connected to the municipal system abstracting water from the aquifer were investigated (Krka Pilot Project, 2006d). The analysis, comparing technical feasibility and costs, stressed that treating drinking water (using a system of ultra-filtration) would be the most cost-effective option (as compared for example to connecting customers to nearby existing water abstraction points with better quality raw water).
Overall, investment costs of such treatment is around 550 million SIT – with operation and maintenance costs accounting for 10% of investment costs. These costs will be paid by the water supply company and eventually passed to customers via water prices.
• Alternative solutions were also investigated for the thermal center of Čatež Spa.
Considering the potential pollution that will occur (pesticides, nitrates, ammonia, bacteriological pollution and possibly smell and taste), a reverse osmosis water purification process was considered as the best alternative and is already considered today by the private operator of the spa. The construction of two reverse osmosis devices with a capacity of 15 l/s will be sufficient to cover the drinking water needs of the spa. Investment costs of these two devices amount to 216 million SIT, with operating expenditures estimated at 96 SIT/m3. These costs will also be paid by the private operator of the thermal center – and eventually passed to visitors of the center via entry prices.
In conclusion, (current and future) water abstraction in the Krska kotlina aquifer does not pose any threat to the sustainability of the aquifer – as abstraction is minimal as compared to recharge. However, because of the degradation of the quality of the aquifer, significant investments will be required for the municipal drinking water supply and for the thermal spa to ensure good drinking water quality complying with set drinking water quality standards to customers and visitors.
4. Designing the programme of measures for reducing pollution from petroleum products in shallow groundwater
4.1 Socio-economic assessment of different water quality objectives
The main objective of the socio-economic analysis in the case study is to analyse socio- economic impacts of alternative quality objectives (described in Chapter 5.3). The analysis was carried out in the frame of cost-benefit analysis where the costs and benefits of programs of measures for reaching each objective have been analysed and compared. The cost-benefit analysis included the following steps:
• Detailed assessment and grouping of pollution sources
• Detailed characterization of measures for each group of pollution sources (including assessing effects and costs of the measures)
• Developing alternative programs of measures (scenarios) and characterizing them in terms of their effectiveness, costs and benefits
• Comparing costs and benefits of alternative scenarios in order to draw conclusion on the potentially most socio-economically efficient scenario (water quality objective) (including sensitivity analysis of the results)
This chapter analyses the different measures that would be required to reduce pollution from petroleum products in shallow groundwater – investigating their costs and expected effectiveness for designing scenarios (or programmes of measures) that achieve the environmental objectives proposed in Chapter 5.3
4.2 Detailed characterization of measures, their effects and costs
As described in the analysis of pressures and impacts, there is an increasing trend in nitrate concentration in groundwater for the Krško polje aquifer. As a result, nitrate concentrations will soon reach the 37,5 mg/l of nitrate for action specified in the WFD. With the current nitrate load to the aquifer, it is expected that nitrate concentration in groundwater will reach an equilibrium value of 60 mg/l by 2018 (thus significantly higher than the drinking water standard of 50 mg/l) if no action is taken.
Different types of measures were envisaged, focusing in priority on the agriculture and household (wastewater collection and treatment) sectors as main contributors to pollution to the aquifer. The main measures identified through discussions with local experts and stakeholders are listed below, information on costs, coverage and effectiveness being summarised in Table 1:
• Establishment of Water Protection Area I (or WPA I) – This measure applies to the first level of water protection areas (Water Protection Areas I or WPAI, defined with a transportation time of water to the abstraction well of less than 50 days) already defined in existing legislation for the abstraction wells of Brege and Drnovo. The measure requires the abandonment of mineral fertiliser and use of organic fertilisation restricted to compost. The costs of this measure represent the end of farm production in arable fields and the installation of (quasi-natural) meadows.
• Establishment of WPA II & III - In other water protection areas (second and third circles of the Brege and Drnovo abstraction wells), it is anticipated to reduce fertiliser input from 188 kg/ha to 170 kg/ha (in line with the requirements of Good Managament Practices). The main costs of the measure are costs of extension for raising awareness for balanced nutrient input, support to rural economies, education, development of efficient monitoring and obligatory preparation of fertilization plans.
• Good Farming Practices - Measures corresponding to good farming practice consider the upgrading of manure pits, a decrease of input use to required standard for light soil and vulnerable area, the prohibition of fertilization during critical time periods of the year, efficient control of carrying out fertilization and other measures. The main costs of the measure are costs of extension for raising awareness for balanced nutrient input, support to rural economies, education, development of efficient monitoring and obligatory preparation of fertilization plans.
• Winter green cover – This measure aims at growing winter crops to capture remaining nitrates and limit leaching during the winter. Costs include the direct costs of farm practices to put winter green cover in place (ploughing, sowing, etc), but potentially also indirect costs that might result from changes in cropping pattern and other farm practices that are required because of the installation of green cover.
• Buffer zones – Buffer zones are grass or forest areas installed along water courses (5 m wide on each side) for limiting runoff and nitrate leaching to mainly surface water.
The cost of the measure is the related reduction in farm profit results from the abandonment of production for the areas under buffer zones. Although it is mainly implemented for surface water quality improvements, it can influence to a limited extend the quality of underground water.
• Ecological farming - Ecological farming implies that mineral fertilisers and chemical products are not used anymore and replaced by alternatives techniques and farm practices that are ecological. Today, there are around 5 to 10% of total farms involved in ecological farming in the area. It is expected that up to 15% of the farms could shift to ecological farming in the Krsko Kotlina area.
• Establishment of stricter WPA II & III for Brege – This measure is proposed for the water protection areas II & III linked to the Brege abstraction well. With this measure, fertilization should be prohibited, leading to a reduction in nitrate surplus from approximately 110 kg/ha to less than 5 kg/ha. The cost of the measure represents the loss in farm production resulting from the drastic reduction in fertilisation.
• Establishment of stricter WPAII & III for Drnovo – This measure is similar to the previous measure but it applies to the abstraction well of Drnovo. The cost of the measure represents the loss in farm production resulting from the drastic reduction in fertilisation. With this measure, fertilization should be prohibited, leading to a reduction in nitrate surplus from approximately 110 kg/ha to less than 5 kg/ha. The cost of the measure represents the loss in farm production resulting from the drastic reduction in fertilisation.
• Installation of septic tanks - Septic tanks have three treatment stages and they need regular sludge transportation to waste water treatment plants. It is estimated that this measure can be implemented for 25% of the population of the area, thus for 7 646 Population Equivalents (PE).
• Construction of small wastewater treatment plans for groups of individual houses (lower than 50 PE) - The measure foresees the installation of small waste water treatment plants with secondary treatment for individual houses or group of houses.
• Wastewater treatment plans for agglomerations between 50 and 2 000 PE. The measure foresees the construction of wastewater treatment plants for small settlements. It is assumed that the outflows from the waste water treatment plants will flow to surface waters and that 1% loss only will go to groundwater (leakage of sewage network).
• Renovation of existing sewage networks. Old networks might record high leakage rates that might have localised damaging impacts if close to abstraction points. The measure foresees the construction of wastewater treatment plants for small settlements. It is assumed that leakages to the aquifer will be reduced from around 10% to around 1%.
Table 1. Coverage, cost and effectiveness information for potential measures considered in the Krska kotlina groundwater case study (source: Krka Pilot Project, 2006b)
Nr.
1. Potential measures
2. Actual coverage
3. Max coverage
4. Additional coverage
(3 - 2)
5. Max. reduction in nitrate concentration
(mg/l)
6. Status of measures 7. Unitary reduction in nitrates
8. Unitary annualized costs
9. Cost Effectiv.
Ratio [ng/l/SIT]
10.
Ranking
1 WPA I 0 ha 70 ha 70 ha 0,634 mg/l Basic 0,0090532 mg/l/ha 1 376 117 SIT/ha 0,0066 9
2 WPA II, III 1 431 ha 2 163 ha 732 ha 0,571 mg/l Basic 0,0007802 mg/l/ha 1 143 SIT/ha 0,6825 3
3 Best management
practice 2 400 ha 4 800 ha 2 400 ha 1,872 mg/l Basic 0,0007802 mg/l/ha 1 286 SIT/ha 0,6066 4
4 Winter Green
Cover 696 ha 2 088 ha 1 392 ha 2,301 mg/l Supplementary 0,0016532 mg/l/ha 41 562 SIT/ha 0,0398 6
5 Buffer Zones 40 ha 139 ha 99 ha 0,804 mg/l Supplementary 0,008&243 mg/l/ha 5 859 SIT/ha 1,3866 2 6 Ecological Farming 348 ha 1 044 ha 696 ha 1,699 mg/l Supplementary 0,0024404 mg/l/ha 47 858 SIT/ha 0,051 5 7 WPA II, III –
additional Brege 0 ha 497 ha 497 ha 4,112 mg/l
Supplementary – Similar costs as for measure 1 but 15% higher because
land 0,0082731 mg/l/ha 1 582 534 SIT/ha 0,0052 10 8 WPA II, III –
additional Drnovo 0 ha 50 ha 50 ha 0,128 mg/l
Supplementary – Similar costs as for measure 2 but 15% higher because
land
0,0025506 mg/l/ha 1 314 SIT/ha 1,9411 1
9
Wastewater Treatment - Septic Tanks
2 548 PE 10 194 PE 7 646 PE 1,023 mg/l Basic 0,0001338 mg/l/PE 42 167 SIT/PE 0,0032 12
10
Wastewater
Treatment plants (<50PE)
0 PE 297 PE 297 PE 0,043 mg/l Supplementary 0,0001433 mg/l/PE 35 273 SIT/PE 0,0041 11
11
Wastewater
Treatment plants (50<PE<2000)
0 PE 1 019 PE 1 019 PE 0,237 mg/l Supplementary 0,0002325 mg/l/PE 19 181 SIT/PE 0,0121 8
12
Wastewater
Treatment plants (PE>2000)
0 PE 8 115 PE 8 115 PE 1,886 mg/l Basic 0,0002325 mg/l/PE 15 758 SIT/PE 0,0148 7
13 WPA I applied to
WPA II & III areas 0 ha 2 163 ha 2 163 ha 19,582 mg/l Supplementary 0,0090532 mg/l/ha 1 376 117 SIT/ha 0,0066 9
;
4.3 Developing alternative programs of measures (scenarios)
Different water quality improvement objectives or scenarios were proposed and analysed from a economic (costs, costs and benefits) point of view to identify the most appropriate program of measures aimed at stabilising or reducing nitrate pollution in groundwater2.
• Scenario 1: The first scenario aims at reducing nitrate concentration by 10 mg/l to ensure that average nitrate concentration in the aquifer is just below the 50 mg/l threshold for drinking water in the longer term. Two sub-scenarios were considered:
o Scenario 1a: measures required for a 10 mg/l reduction are implemented from 2006 onwards. This scenario ensures that nitrate concentration in groundwater remains always below the 50 mg/l limit. Thus, no water treatment is required by municipal water supply operators and by the thermal spa abstracting groundwater from the aquifer;
o Scenario 1b: measures required for a 10mg/l reduction are implemented from 2012 onwards. This postponement of leads to the need to invest in treatment for drinking water operators and for the thermal spa as nitrate concentration in groundwater will go above the 50 mg/l threshold but for a limited time period.
Once nitrate concentration is below the 50 mg/l threshold, installed treatment facilities will not be required anymore leading to savings in operation and maintenance costs of these facilities as compared to Scenario 1a.
• Scenario 1c: The third scenario aims at reducing nitrate concentration by 22,5 mg/l, i.e. ensuring groundwater reaches the trend-reversal threshold of 75% of 50 mg/l equal to 37,5 mg/l, with measures being implemented from 2006 onwards. Such a scenario will provide a safety margin, ensuring that short term variability in nitrate concentration that might occur as a result of climatic variability or variability in nutrient use never leads to nitrate concentration above the 50 mg/l threshold.
• Scenario 2: The scenario aims at reducing nitrate concentration by 50 mg/l so it reaches a nitrate concentration of 10 mg/l close to the (background) natural conditions. Proposed measures are also implemented from 2006 onwards.
The implications of these different scenarios in terms of expected nitrate concentration in groundwater are presented in Figure 6 below.
Base case = 60 mg/l
Scenario 1a: - 10 mg/l and measures implemented in 2006 Scenario 1b : - 10 mg/l and measures implemented in 2012
Scenario 1c: -22.5 mg/l and measures implemented in 2006
Scenario 2: -50 mg/l and measures implemented in 2006 Drinking water threshold
= 50 mg/l
Trend-reversal threshold
= 37.5 mg/l
Close to natural background
= 10 mg/l Nitrate concentrations in
mg/l
Yea ²r
2006 2012 2018
Figure 6. Expected changes in nitrate concentrations in the Krsko kotlina aquifer as a result of different scenarios (source: Krka Pilot Project, 2006d)
2 It was assumed that the measures proposed for reducing nitrate pollution (see in particular measures proposed for the agriculture sector) would also help reducing pesticide pollution.
4.4 Assessing costs of alternative scenarios
The most cost-effective set of measures, using information provided in Table 1, were identified for the different scenarios. The results are presented in Table 2 in terms of proposed coverage for each measure (in terms of area or PE) and costs for each measure and for the different sets of measures. Only scenarios with implementation of measures starting in 2006 are presented in this table for clarity reasons (Scenario 1b is missing)
• Overall, implementing the most cost-effective set of measures for reducing nitrate concentration in groundwater by 10 mg/l will cost 1.417 million Euros or 202 Euros per hectare3.
• If basic measures that are required for the implementation of existing legislation (urban wastewater treatment directive, nitrate directive) are selected in priority, this leads to an additional cost of around 1.1 million Euros for reaching the same nitrate concentration reduction. Overall, selected basic measures first leads to average costs per hectare of 368 €, thus 80% higher than the previous figure.
• Reducing nitrate concentration in groundwater by 22.5 mg/l and 50 mg/l leads to significantly higher costs for proposed sets of measures, around 10 million Euros (1 417 € per hectare) and 34 million Euros (4 833 € per hectare), respectively.
It is important to stress that the measures that are proposed for reducing nitrate and pesticide pollution to groundwater have also a positive impact on pollution to surface water.
Based on the expected effect of these measures to reducing groundwater pollution and surface water pollution, it was assumed that only 65% of the costs presented in Table 2 would be attributed to groundwater protection – an element that is important for the next chapter and the overall cost-benefit analysis performed for the different groundwater quality improvement scenarios4.
3 The total area of the Krsko kotlina aquifer is considered for estimating per hectare costs.
4 In the cost-benefit framework, the alternative would have been to keep the total costs of measures as presented in Table 2 and to estimate related benefits to surface water. However, this would have required information and resources not available within the team of experts involved in the groundwater case study.
Table 2. Proposed set of measures for achieving different environmental objectives (reduction in nitrate concentration) for the Krska kotlina aquifer (source: Krka Pilot project, 2006b)
Package of measures Total costs of package of measures
Scenario 1a Reduction - 10 mg/l
Scenario 1a Reduction - 10 mg/l
Cost-effective programme
Basic measures
first
Scenario 1c Reduction - 22,5 mg/l
Scenario 2 Reduction - 50 mg/l
Unitary cost
Cost-effective set
Basic measures first
Scenario Ac Reduction - 22,5
mg/l
Scenario 2 Reduction - 50
mg/l
WPA I 70 70 70 70 1.376.117 96.328.190 96.328.190 96.328.190 96.328.190
WPA II, III 732 732 -523 -1.431 1.143 836.676 836.676 -597.789 -1.635.633
Best management practice 2.400 2.400 2.400 -2.069 1.286 3.086.400 3.086.400 3.086.400 -2.660.734
Winter Green Cover 1.392 836 1.392 -696 41.562 57.854.304 34.745.832 57.854.304 -28.927.152
Buffer Zones 99 99 99 99 5.859 580.041 580.041 580.041 580.041
Ecological Farming 696 696 696 47.858 33.309.168 33.309.168 33.309.168 0
WPA II, III – additional Brege 1.582.534 0 0 0 0
WPA II, III – additional Drnovo 50 50 50 50 1.314 65.700 65.700 65.700 65.700
Wastewater Treatment - Septic
Tanks 7.646 7.646 7.646 42.167 0 322.408.882 322.408.882 322.408.882
Wastewater Treatment plants
(<50PE) 297 35.273 0 0 0 10.476.081
Wastewater Treatment plants
(50<PE<2000) 1.019 1.019 1.019 19.181 19.545.439 0 19.545.439 19.545.439
Wastewater Treatment plants
(PE>2000) 8.115 8.115 8.115 8.115 15.758 127.876.170 127.876.170 127.876.170 127.876.170
WPA I – rest 1.255 5.520 1.376.117 0 0 1.727.026.835 7.596.165.840
Total SIT 339.482.088 619.237.059 2.387.483.340 8.140.222.824
Total € 1.417.462 2.585.541 9.968.615 33.988.404
Per ha 202 368 1.417 4.833
5. Public perception of shallow groundwater pollution:
methodology and results of the survey
A contingent valuation survey was developed for estimating monetary values for benefits linked to groundwater improvements in the Krska kotlina aquifer. The main objectives of the survey were:
• To elicit the total economic value for shallow groundwater quality;
• To estimate the value of public benefits associated with different programs of measures or scenarios for improving groundwater quality (see previous chapter).
The following sections present the approach developed and main results obtained from the contingent valuation survey for the groundwater case study in Slovenia. It is directly builds on the report prepared by the Krka Pilot project for presenting the results of the contingent valuation survey (Krka Pilot Project, 2006c).
5.1 Organising the survey
5.1.1 Building the questionnaire
A questionnaire was developed for the contingent valuation survey. This questionnaire is composed of seven sections described below:
• Section I: general introduction to the institutional context and the main objective of the survey.
• Section II: the respondent’s general opinion on (i) environmental issues in general (as compared to other problems they might face) and (ii) water management issues in particular - for both surface water (the Sava and the Krka rivers that are expected to be very familiar to people of the area) and groundwater (which problems do they see today, which past/expected evolution)….
• Section III: the respondent’s connection to water/water use in terms of their source of drinking water, their level of water services, their access to groundwater via own wells, their relationship to surface water via walking along the river, swimming… This section also included a question on the respondent’s monthly water bill.
• Section IV: the respondent’s assessment of proposed actions for solving groundwater pollution problems in the Krska kotlina aquifer. This section included the respondent’s perception of the current groundwater situation in the Krško kotlina aquifer, the importance given to groundwater improvement, his/her willingness to pay for restoring groundwater quality to different quality levels and how much (see next section for more details on the proposed groundwater improvement scenario) and the main reasons behind these choices. The preferred payment vehicle was also investigated.
• Section V: the respondent’s socio-economic profile (sex, age, household size, education, income class…)
• Section VI: reported difficulties in filling the questionnaire in particular willingness to pay questions.
• Section VII: specific comments from the interviewer that might help understand responses during the analysis (e.g. if the respondent has been influenced by another person in his/her responses, if an unexpected event disturbed the interview…)
The questionnaire was developed in parallel in both Slovenian and English languages. The full version of the questionnaire in English is available in Krka Pilot Project (2006c).
5.1.2 Defining the scenarios
Two scenarios for groundwater quality improvements were defined and proposed to respondents in a staged approach. These scenarios differed in terms of expected impact on groundwater quality, overall impact on the potential use of the aquifer and potential measures aimed at improving water quality to the required levels.
• Scenario 1 aims at stabilising nitrate and pesticide pollution in groundwater so drinking water quality is ensure in the long term for the entire aquifer5.
• Scenario 2 is more ambitious and aims at restoring groundwater quality close to natural conditions, thus eliminating risk to connected natural areas and ecosystems.
Table 3 summarises the main features of the two scenarios.
Table 3. Main features of the two scenarios proposed to respondents Components
of the scenario
Scenario 1 Scenario 2
Expected
impact on groundwater quality
An action programme with protection measures, targeting the different sectors at the origin of pollution (agriculture, households and sewerage, industry…), can be proposed for stabilising nitrate and pesticide pollution in the groundwater.
In addition to the measures proposed in scenario 1, stricter restrictions on land planning, bans of polluting products, compulsory treatment of wastewater for all…
can be imposed to reduce even further pollution to the aquifer. This would bring groundwater quality close to natural conditions.
Potential measures and sectors targeted
• The implementation of good agricultural practices for the agriculture sector;
• Controlled used of pesticides and strict application of good practices in all sectors (agriculture, transport, gardening, etc)
• The installation of new sewage and the modernisation of existing ones for reducing leakages;
• Building of manure storage for the larger farms for better manure management;
• Improved management of sceptic tanks (e.g. regular emptying) for isolated houses and installation of modern sceptic tanks for all new constructions/houses
• Strict land planning with banning new activities that might potentially pollute the aquifer,
• Shift to more ecological farming for agriculture for selected sensitive areas;
• Baning pesticide use for gardens, transport infrastructure and municipal use;
• Obligation for replacement & proper management of sceptic tanks for all isolated houses
• Shift to less polluting inputs and products for industries and households….
• Active awareness raising campaign for the entire population
Overall impact
This will ensure in the longer term a drinking water quality for the entire aquifer - additional costly treatment for drinking water will not be required. However, some risk might remain for connected nature protected areas and ecosystems.
Such an ambitious action programme would ensure drinking water for the entire aquifer similar to scenario 1. In addition, it would ensure no risk to connected nature protected areas as required for healthy development of natural ecosystems, birds, fishes…
In order to test the potential impact information provided to respondents might have on their willingness to pay, two different questionnaires were prepared with different levels of information on scenarii. In the first questionnaire, the entire information presented in Table 1 was explained in simple terms. In the second questionnaire, this information was simplified
5 Scenario 1 proposed for the contingent valuation survey investigates benefits from keeping groundwater drinkable which is the outcome of Scenarios 1a, 1b and 1c presented in the previous chapter of this report. Scenario 2 proposed for the contingent valuation survey is coherent with Scenario 2 presented in the previous chapter of this report.
by eliminating reference to (i) the source of pollution, (ii) the fact that pesticides are already present in groundwater today (mention was made of pollution in general sense) and (iii) potential measures and sectors targeted for reducing groundwater pollution.
5.1.3 Elicitation format
The stated choice format used to elicit values included several steps.
• Respondents were first asked whether they would be willing to pay for the first scenario.
• If their answer was “yes”, they were then asked to attach a value to this scenario via an open-ended question using a payment card developed based on the results of pre-testing.
• Respondents willing to pay for the first scenario were then asked whether they would be willing to pay for the second (more ambitious) scenario.
• If their answer was “Yes”, they were then asked attach a second value incremental to the first value they were already willing to pay for the first scenario, using a similar payment card as the one presented in Box 1.
Once all willingness to pay questions had been answered, respondents were asked to select their preferred payment vehicle.
5.1.4 Pre-testing
Pre-testing of the draft questionnaires took place in April 2006 and lasted two days (April 12
& 13, 2006). Pre-testing was made by the seven interviewers (university students) who had been hired for undertaking the full survey – with involvement of one expert from the Geological Survey of Slovenia in meetings for explaining groundwater management issues in the Krska kotlina aquifer and the different scenarios to interviewers. During the first day, around 20 interviews were carried out in Ljubljana. And more than 30 interviews were warried out during the second day in the Krska kotlina area. Pre-testing helped in revising questionnaires (format, wording, order of questions, open-ended questions replaced by limited number of choices…) in particular with regards to:
• The values proposed in the value card – higher values had to be included as a result of testing;
• Lower income classes were split to cover the income situation in the case study area – and the highest income classes originally proposed (600 000 to 700 000 SIT per month, 700 000 to 800 000 SIT per month, and above 800 000 SIT per month)6 were replaced by a single income class;
• The proposed “certainty scale” and related questions on certainty in respondents’
answers – aimed at assessing whether willingness to pay answers were given by respondents with certainty – had to be removed from the questionnaire as a result of negative reactions from respondents and uneasiness from interviewers. Different forms of questions were tested but finally removed – leaving the possibility for respondents to modify their value for the first scenario when answering values for the second scenario as a means to get closer to certain values;
• The payment vehicle – negative reactions to water bills and taxes led to shifting the question on payment vehicle after the willingness to pay questions;
6 Exchange rate: 1 € = 243 SIT (July 2006)
