Value of Wastewater Treatment
Attributes
Medium: Water
Country: Thailand
Analytical Framework(s): Contingent Valuation
Unit(s): Mean WTP
Study Date: 1998
Publication Date: 1998
Major Result(s)
| Resource/Environmental Good | THB, per person per month (1998) |
THB, per person per month (2014)1 |
USD, per person per month (2014)2 |
|---|---|---|---|
| Mean WTP for the treatment of water quality 1 | 100.81 | 139.38 | 4.23 |
| Mean WTP for the treatment of water quality 2 | 115.03 | 159.04 | 4.83 |
About the Inflation Adjustment: Prices in Thailand (THB) changed by 38.26% from 1998 to 2014 (aggregated from annual CPI data), so the study values were multiplied by 1.38 to express them in 2014 prices. The study values could be expressed in any desired year (for example, to 2025) by following the same inflation calculation and being sensitive to directional (forward/backward) aggregations using your own CPI/inflation data.
Study Note: This research aimed to estimate the willingness of Bangkok residents to pay for improved water quality by conducting a contingent valuation survey, and suggest economic instruments to encourage this willingness to pay, such as user fees, property taxes, and other measures.
Study Details
Summary: In recent years, environmental degradation has become an increasing concern in Thailand. Of the environmental problems and challenges facing the Kingdom, water pollution is one of the most serious. Among the rivers in Thailand, the Chao Phraya River is the most contaminated. Recently, the Pollution Control Department reported that the levels of dissolved oxygen in the lower reaches of the Chao Phraya River have been close to zero since 1990, and that by the year 2000, the "King's River" may well be "dead". The finality of this observation is not just an academic hyperbole: so reduced is the level of dissolved oxygen in the lower reaches of the Chao Phraya River that most aquatic life find it impossible to survive.
Site Characteristics: The study area is the Bangkok Metropolitan Area. Bangkok is not only the capital city, but is also the center of commerce, service, industry, national and international transportation, and the center of government administration. Bangkok covers an area of 1,568.753 km2 with an average height above mean sea level of 1.5 m. The area is called the lower Chao Phraya River basin or the Chao Phraya delta plains. The population in Bangkok as of 31 December 1996 is 7.5 million. The number and distribution of the population in the community directly impact on wastewater quantity. Based on the 1980 and 1990 population censuses, the population projection is estimated to increase from 7.5 million in 1996 to 11.1 million in 2017. Even more striking is the projection for wastewater from the residential sector to increase from 575.85 million m3/year in 1996 to 1,044.93 million m3/year in 2017. Bangkok will continue to strive for higher quality levels of urbanization and will continue to pay a higher "price" for environmental degradation due to water pollution, unless adequate investments in pollution controlfacilities are instituted for effective wastewater management.
Comments: The study offers several variants of the contingent valuation method survey. In one variant, households are presented two possible water quality scenarios. They are simply asked how much they are willing to pay for wastewater treatment charges for the following scenarios: Improve the water quality from 'boatable' to a level where fishing could take place, and Further improve water quality from 'boatable' to a level where swimming is possible.