Water Pollution
According to several studies, there are three main sources of
pollutants in the Chao Phraya River and its tributaries, and the city
canals. These are factories, households and restaurants. Although
large factories are required to install water treatment facilities in
order to obtain their annual operating permits from the Department of
Industrial Works (DIW), this does not apply to many medium and small
plants. The existing household water treatment capacity serves about
only two percent of Bangkok's population. The wastewater of most
households is discharged into canals and then drained into the river.
The six most polluted canals share over 54 percent of total domestic
pollution loads discharged into the Chao Phraya River. Domestic
sources account for about 75 percent of the pollution in Chao Phraya
River, while factories account for remaining 25 percent.