Thailand is a country in Southeast Asia whether you like it or not. Certainly the people that live there have no problem with that so you should just let it go.
A river runs through it, the Mekong to be exact. It is a very large river that touches everyone in Thailand in one way or another especially if you are drunk and happen to fall in. There are boats everywhere, both floating and sunk, making the Mekong a major transportation corridor, a watery highway if you like, or even if you don't like. It provides life-giving water for people and crops, with at least humans known to be drinking and washing with it. The bad part is that the Mekong is also everybody's toilet. Even moving upstream wouldn't help that because the river starts far up in Tibet and the water has already passed through every human, fish, rice plant and cow for a thousand miles. Since the river is often muddy, people are used to surprises in their drinking water, which ranges from garbage to giant freshwater stingrays. So if you order coffee in a restaurant there, always stir it before drinking.