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)

• The different figures, diagrams and simple text prepared for interviewers to present the actual situation and scenarios to respondents.

Pre-testing also helped training the seven interviewers in the use of the questionnaire and survey.

5.1.5 Sampling procedure

The sampling plan was developed in accordance to two specifics characteristics of respondents and to geographic location.

Age and gender

Data was collected from the statistical offices of the Krška kotlina area (municipalities of Krsko and Brezice) for assessing the relative importance of age groups and sex classes in the total population. This information was used as guide during the last days of the survey for the interviewers to select the last respondents to ensure the sample statistics would be close to the statistics of the overall population.

Location

The population was divided into 3 categories according to the distance of settlement in which people are living as compared to the Krška kotlina aquifer. The first category includes settlements which lay on top of the aquifer. The second category includes people living in settlements close to the hydrological boundaries of the aquifer. And the third category includes respondents living in municipalities far from the aquifer (between 5 and 30 km).

5.1.6 Practical organization of the survey

The survey took place between April 13, 2006 and May 20, 2006. Overall, the interviewers who participated in the pre-testing interviewed 429 respondents during day time - 57 % of respondents being interviewed in the street and 43% of respondents being interviewed at the respondent’s own home. Data were entered by the interviewers using an Excel-based data entry format. All data were then checked for correcting data entry mistakes and identifying possible outliers that might be discarded during the follow-up statistical analysis performed using in particular the Stata software.