Reports, Case Studies & Assessments

Emissions Inventory for Inland Water Transport in Bangkok, Thailand


Every day, more than 250,000 passengers in Bangkok takes Cross-river ferries, Chao Phraya express boats and Saen Saep express boats which connects two sides of Bangkok city to other modes of public transportation, such as motorcycle taxi, bus, sky train, subway. Although inland water public transport is one of the major transport means in Bangkok, the emission from this sector has not been studied, nor included as a separated emission source in the previous inventories. Boats using 15-20 years old engines emit large amount of black smoke while departing and embarking from piers and contribute to Bangkok’s air pollution problem.

To complete the overall emission sources for better air quality management in Bangkok, Thailand Pollution Control Department (PCD) and Asian Institute of Technology (AIT) with the supports from the Climate and Clean Air Coalition’s (CCAC) Solutions Center and the United Nation Environment Programme (UNEP) conducted the project to estimate the emission from inland water transport in Bangkok and provide recommendations on emission reduction to the government of Thailand. The results are necessary to better understand and manage air pollution emissions, especially PM2.5, since every year during November to April, Bangkok has been experiencing high PM2.5 concentrations.

Switching boat engines to Euro 6 with 10 ppm sulfur fuel could reduce 98% of PM2.5 emission from the current situation. Using 10 ppm sulfur fuel with the existing engines would only reduce PM2.5 emissions by 5% from the current situation. Thus, the best policy recommendation for PM2.5 emission reduction from boats are promoting the use of 10 ppm sulfur and switching to Euro 6 engines. Use of electric motors will bring tail-pipe emissions to zero and can significantly reduce air pollution along the river and canals. Other recommendations include limiting the age of engines, and reducing idling through better operations in stations and route planning. The researchers also acknowledge the potential of inland waterways to help decongest traffic congestion in Bangkok. Expansion and improvement of inland passenger transport could lead overall reduction of air pollution in the city, while providing better mobility to its citizens.

This project also developed an MS Excel emission calculation template for inland water transport which can be used to assess the emission of inland water transport for other cities. Many major cities in Southeast Asia, and the world, are in major rivers and canals connecting to the coast. While many inland waterways are used for freight, not many cities are looking at passenger transport. Bangkok provides a good example in connecting road and waterway public transport. Inland waterways have the potential to alleviate road traffic and reduce overall emission from transport.