It could, but it's not really ...
Published by Soren Cicchini, Seeking Employment at Open to Opportunities
It could, but it's not really cost effective. A more sensible use of laundry greywater is on gardens. As well as reducing the use of clean water on plants, the phosphates from the detergents are readily used as nutrients by most plants, and residual detergent is effective at wetting hydrophobic soils (many sandy soils become hydrophobic after extended dry spells, particularly those with high organic content, which appears to leave a waxy residue - http://www.abc.net.au/gardening/stories/s2260793.htm).