7. Designing the programme of measures for reducing pollution from petroleum
8.2 Analysis of the survey data: descriptive statistics
This section summarises the main results obtained from the survey data (510 questionnaires filled) in terms of descriptive statistics.
The following tables provide summary statistics for selected socio-economic indicators, comparing in particular the sample averages/values with the values for the entire population of the city of Riga obtained from general statistics.
Table 7. Gender in the total population of the city of Riga and in the sample Gender Total population (%) Sample (%)
Women 55.5% 57.8%
Men 44.5% 42.2%
Table 8. Relative importance of different age groups in the total population of the city of Riga and in the sample
Age group Total population (%) Sample (%)
20-29 18.5% 18.8%
30-39 17.4% 24.7%
40-49 19.2% 25.3%
50-59 16.2% 13.0%
60-69 14.3% 11.7%
70-79 10.5% 5.9%
80 and more 4.0% 0.6%
Total 100% 100%
Table 9. Relative importance of socio-professional categories in the total population of the city of Riga and in the sample
Categories Total
population (%) Sample (%) Agriculture, hunting, forestry 0.4% 1%
Industry 13.9% 10.8%
Constructing 6.7% 8.3%
Services 36.7% 38%
Tourism 2.9% 2.3%
Public administration 4.0% 12.5%
Education 6.0% 10.8%
Health and social care 4.3% 6.5%
Student 21.5% 6.5%
Unemployed 3.5% 3.5%
Total 100.0 100.0
Table 10. Relative importance of education in the total population of the city of Riga and in the sample
Education level For entire population
(%) For the sample (%)
Basic + Primary 18.4% 5.7
Secondary 26.7% 20.6
Secondary specialised 19.4% 30.7
Higher 18.9% 40.9
Other 16.6% 0.6
TOTAL 100 100
Overall, the sample has an over-representation of inhabitants from 30 to 49 year old, having secondary specialised and higher education and working in public administrations and in the education sector. Gender is representative in the sample.
The majority of respondents live in the city of Riga while the remaining (12%) are coming from other parts of the Riga district or from other cities. The average household size for the sample is higher (3.1) than indicated by the official statistics (2.4 respectively). Around 23%
of the respondents live in individual houses, while 26% of the respondents have their own garden. Figure 5 presents the frequency distribution of the sample for different income categories8.
14,00 12,00 10,00 8,00 6,00 4,00 2,00
income
100
80
60
40
20
0
Frequency
Mean = 5,002 Std. Dev. = 2,74973 N = 509
Histogram
Figure 5. Frequency distribution of income in the sample
Other statistics for the sample related to uses, perceptions, attitudes and preferences are summarised below:
• 16% of the respondents do not have connection to public water supply services. And 19% have their own well allowing them to abstract groundwater at home. Most use their wells because of the absence of alternative (no connection to municipal network).
8 The meaning of the different categories are found in the full questionnaire used during the survey that is provided in Annex 3.
• 46% of the respondents connected to the drinking water supply network do not know the origin (whether it is groundwater or surface water) of the water they drink/use.
• 42% of the respondents connected to the drinking water supply network do not know their water bill. For those who know their bill, the average water bill is reported to be equal to 10.5 euro per month (or 126 Euros per year).
• 15% of the respondents never walk along rivers or lakes, 57% never swim in outdoor water bodies, 78% never fish and 67% never use boats.
• Most respondents identify social problems as priority, with environmental problems and economic ones being considered as second and third.
• Water is mentioned as key problem in only 10% of the cases. Environmental
problems are mentioned in 65% of the cases, with 29% of the cases where they are mentioned as priority areas. Pollution in groundwater is mentioned as important by only 5% of the respondents.
• 41% of the respondents could not assess current shallow groundwater quality or irs evolution over time.
• 66% of the respondents stated that good shallow groundwater quality is important or very important for them, mainly because of direct use considerations (65% of the cases).
• 48% of the respondents were not informed about the situation in terms of shallow groundwater pollution that was presented to them. Only 6% of the respondents consider this situation as not realistic.
Overall, the statistics presented above stress the poor relationship of respondents with water in general and with groundwater in particular, along with their poor knowledge of the actual situation with regards to groundwater use and pollution.
• For 19% of the respondents, groundwater improvement scenarios presented to them were not achievable.
• 8% of the respondents have chosen the Basic scenario, 30% have chosen Scenario 1 (medium improvement scenario), and 62% have chosen Scenario 2 (maximum improvement scenario). Most of those who have chosen the Basic scenario are not willing to pay, while around 50% of respondents choosing other scenarios are willing to pay (see Table 11).
Table 11. Share of respondents willing to pay for different groundwater quality improvement scenarios
All scenarios Basic scenario Scenario 1 (Medium improvement)
• Environmental considerations are most often cited as the main reason for choosing a scenario for respondents who have chosen Scenario 2 (maximum improvement) as compared to respondents who have chosen other scenarios. Financial considerations are often cited by respondents as reasons for choosing the basic scenario or Scenario 1.
• 41% of the respondents are willing to pay additionally to the amount they stated for the chosen scenario if the quality of other waters would be improved simultaneously.
• Only 2% of the respondents are members of environmental organization.
• Around 6% of the respondents had difficulties in responding to the questionnaire. And 9% of the respondents felt the information provided to them to decide on scenarios and propose values was not sufficient.
The main reasons for not being willing to pay for groundwater improvement programmes that were cited by respondents are as follows:
• For 43% of the respondents – “my income is too low” (zero bidders)
• For 15% of the respondents – “groundwater quality improvement is not important enough and there are other things that are more important” (zero bidders)
• For 19% of the respondents – “contributing financially to groundwater improvement programmes is not acceptable in principle” (protest answers)
• For 23% of the respondents – other reasons (all reasons mentioned are protest answers)
Table 12 provides the amounts in Euros respondents are willing to pay to support the implementation of proposed groundwater improvement programmes.
Table 12. What are respondents willing to pay for groundwater quality improvements? (values in € per household per year)
Statistics WTP for all scenarios
WTP for Basic scenario (8 respondents)
WTP for Scenario 1 (Moderate improvement) (79 respondents)
WTP for Scenario 2 (Maximum improvement) (155 respondents)
Minimum 1 1 1 1
Maximum 213 142 142 213
Average 24.5 36 24.2 23.5
Median 14.23 14 14 14
Mode 7.11 14 14 7
Standard deviation 31.06 50.6 27.6 29.7
The average willingness to pay (WTP) values for the different scenarios differ only very slightly. And differences between scenario averages are not statistically significant. The average WTP value is equal to 24.5 euro per household per year amounts to 19% of the average yearly water bill (126 euro per year per household). The distribution of WTP values is displayed in Figure 6 below9.
9 Note: the distribution is not normal even if values are standardized.
Figure 6. Distribution of the WTP values for the sample
To understand the relative importance of use and non-use considerations in respondents’
willingness to pay, a scale from -5 (use values) to +5 (non-use values) was proposed for respondents to explain their choice. Figure 7 presents the results obtained – stressing that the majority of respondents balance use and non-use values in choosing scenarios and willingness to pay, with a slightly higher importance given to use values.
0.2.4.6.8Density
-5 0 5
Scale Use value
considerations
Non-sse value considerations
Figure 7. Relative importance of use and non-use values in justifying people’s willingness to pay for groundwater quality improvements
On the issue of site selection for prioritising groundwater quality improvements, respondents stressed the importance of cleaning sites close to drinking water abstraction points (313 answers), then sites causing pollution for surface water (269 answers, then sites with very high pollution levels (204). The closeness of the site to the respondent’s home or its location in a residential part of the city received less attention (122 and 10 responses, respectively).
Differences in WTP values for different sub-samples differentiated by the location of respondent’s home or their current use of shallow groundwater were investigated. Table 13 presents different statistics computed for different sub-samples.
Table 13. Differences in WTP values depending on location and shallow groundwater use (values in € per household per year)
Sub-sample No of Location Living in other part of the
district and other cities 63 33 142.3 1.4 21.3 35.6 32.7
Respondents living outside the city of Riga have a higher mean WTP value than those living in the city – which is contrary to expectations. Respondents using shallow groundwater (or thinking they use shallow groundwater) have a mean WTP value slightly higher that the mean value of non-users..
From the information presented above, it is unclear whether respondents effectively understand the good they are asked to value. Respondents might attach higher use value for shallow groundwater under Riga than it should be in the reality, the obtained WTP value resulting of a mix of considerations linked to what respondents think they use as drinking water, what they know/think their friends use, their lack of knowledge about the origin of water used at home, in public places and at their working place, etc.
When designing the survey, it was expected that non-use values could be approached by comparing WTP values for respondents living outside Riga with values of respondents living in Riga and using shallow groundwater. Responses however stress that many use value and direct (drinking water) use aspects are considered by respondents even those expected to have mainly non-use benefits from groundwater quality improvement. This could be explained by the fact that people interviewed in Riga visit Riga often, work in Riga or even might stay in Riga for longer periods (e.g. for an entire working week). Thus, they use Riga public water supply and attach a drinking water value to shallow groundwater as they do not know whether drinking water comes from shallow groundwater or not.
In the initial design of the survey, it was assumed that the distance between the respondent’s home and Riga would influence the value respondents attach to shallow groundwater. In line with the previous comment that would suggest that the important factor is how often/how long people visit Riga (a question that was unfortunately not included in the questionnaire), results shows that distance is not an important factor explaining different WTP values..