Organising the survey

8.1.1 Building the questionnaire

The questionnaire developed for the contingent valuation survey included the following sections:

• General introduction to the institutional context and the main objective of the survey.

• Section I: the respondent’s connection to water (both surface water and groundwater), water use and water services.

• Section II: the socio-economic and environmental issues identified by the respondent as priority/the most important – including the respondent’s perception to water quality and its past changes;

• Section III: the presentation of today’s pollution in shallow groundwater and respondent’s perception of this situation (is it realistic or not)

• Section IV: respondent’s perception of proposed programmes for improving groundwater quality, along with their willingness to pay for these programmes. This section also includes questions on the proposed payment vehicle and on the main reasons behind people’s willingness to pay.

• 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 Latvian and English languages. The full version of the questionnaire in English is provided in Annex I of the present report.

8.1.2 Defining the scenarios

In a stated preference format, different groundwater quality improvement situations or scenarios are proposed to respondents. The scenarios were built on different sets of measures ensuring reaching “good” groundwater quality for different compliance regimes.

Compliance regimes were expressed in terms of the relative numbers of sites that would be restored up to the “good” quality (or number of sites that would be left polluted) complemented by information on (i) whether contaminated sites had connection to surface water, (ii) the relative level of pollution in shallow groundwater, and (iii) the proximity/integration of polluted sites in residential areas of the city of Riga. Three scenarios were considered for the contingent valuation survey in line with the programme of measures proposed and analysed in the previous chapter of this report:

• Base case (basic scenario): Limited improvement with the implementation of preventive and restoration measures that are set by current legislation and for which financial resources have already been allocated/decided (from EU funds, national and municipal budgets);

• Scenario 1: Moderate improvement resulting from the implementation of all measures of the basic scenario and additional restoration measures for all contaminated sites having particularly high pollution levels and posing a potential risk for connected surface waters. Shallow groundwater would be cleaned up to the “good” groundwater quality in all restored sites;

• Scenario 2: Maximum improvement with restoration of all contaminated sites of the shallow groundwater body to “good” groundwater quality.

It has to be noted that each scenario was characterised by two attributes: its environmental impact in terms of number of sites restored to good groundwater quality and expected improvements in connected surface water; and its total implementation costs (investment costs, operational & maintenance costs).

8.1.3 Elicitation format

The stated choice format used to elicit values included two steps. Respondents were first asked to choose their most desired scenario. Then, they were asked to attach a value to this scenario in terms of their willingness to pay for improvements in shallow groundwater quality.

This valuation question was an open-ended question using a payment card (see Box 1) developed based on the results of first pre-testing⁷.

Box 1. Payment card used for the survey/questionnaire

LVL 0 LVL 5 LVL14 LVL23 LVL40 LVL 60 LVL 100

LVL 1 LVL 8 LVL15 LVL25 LVL45 LVL 70 Other amount Please specify!

LVL 2 LVL10 LVL18 LVL30 LVL50 LVL 80

7 An iterative bidding game was considered during the pre-testing phase. However, the respondents did not have difficulties to state the amount they would be willing to pay – thus the simpler payment card option was chosen.

8.1.4 Pre-testing

Pre-testing of the draft questionnaires took place in two phases:

• A first pre-testing of selected questions (in particular those linked to people’s perception of groundwater quality improvement and of their willingness to pay for such improvements) was made in February 2006 with students from the Faculty of Economics of the Riga University. This first pre-testing helped drafting questions and provided first information on the range of values one might expect from a survey;

• A second pre-testing of the full questionnaire took place on April 25 & 26, 2006.

Overall, 30 interviews took place – with an average time of 30 minutes per interview (which was considered as acceptable). This second pre-testing also helped training the interviewers that were hired for undertaking the survey in the use of the questionnaire.

8.1.5 Sampling procedure

A sample size of around 500 respondents was proposed to ensure statistically significance of regression analysis results. It was expected that such sample size would be sufficient to ensure adequate representativeness of the sample to the total population of the city of Riga.

Inhabitants of the city of Riga and people living outside of the city were included in the sample. It was expected that the difference in responses between inhabitants from Riga and others would help capturing non-use values. Both inhabitants connected to public water supply services (as non-users – as surface water is the sole source of water for the municipal drinking water network) as well as inhabitants having their own wells (direct users) were included in the survey. Specific attention was made to ensure that a sufficiently high number of direct users would be included in the final sample. It was also expected that differences between users and non-users might help capturing use values.

8.1.6 Practical organization of the survey

The survey was started the first week of May 2006 and finalized on May 20^th 2006. In total, eleven interviewers were employed to carry out the survey (students from the Latvian University and professional interviewers from a public institution and company doing quantitative surveys), the same who had participated in the second pre-testing phase. And they interviewed 510 persons during this period. Both home interviews and outdoor interviews were performed – with 225 home interviews equivalent to 44% of the sample, and 285 outdoor interviews (street interviews, interviews in shopping centers, squares, job places….) equivalent to 56% of the sample. Interviews were carried out in different districts of the city, people living outside the case study area being also interviewed in the city (e.g. at the Riga city train station when arriving to/leaving from Riga).

Data entry was started right after the start of the first interviews and was completed by May 20, 2006. Data was entered by 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 statistical analysis. Statistical analysis took place between June and September 2006, using in particular the Stata statistical software.