* अपशिष्ट जल (apashisht jal) - This is the most common and literal translation.
* गंदा पानी (ganda pani) - This is a more informal translation and means "dirty water".
* नाली का पानी (naali ka pani) - This literally means "water from the drain".
The best translation will depend on the context and the desired level of formality.