Although this may not be the particular term you're looking for, I thought I should mention that minorly contaminated water previously used for washing, such as that from sinks, baths, and showers, is specifically referred to as greywater.

Although this may not be the particular term you're looking for, I thought I should mention that minorly contaminated water previously used for washing, such as that from sinks, baths, and showers, is specifically referred to as "greywater" (also "graywater", "grey water", "gray water").

Wiktionary defines it as "water that is not clean enough to be potable, such as having been used for washing, but not contaminated with fecal matter or other source of dangerous bacteria or dangerous or noxious materials."