Cha Va is among the most polluted rivers in the southwestern region. Wastes of all kinds, including glass debris, needles, and animal bodies have been thrown from a near-by market into this dead river for years. Pipes from toilets are also connected to the river.

But this is a good environment for trun chi (a species of worm), so poor people consider the river a good source of income.

They can collect 3-5 kilos of trun chi per day.

A kilo of trun chi is priced at 25,000-30,000 dong ($1.2-1.6).