When people hear “grey water”, they usually think in terms of capturing the water from showers and sinks, or possibly the clothes washer, to reuse in the garden. But grey water (or graywater) may be available in large amounts in industrial settings as well. In this case it may be rinse water from a process, such as CIP (Clean In Place), in addition to the more traditional sanitary sources.
Careful analysis is required for grey water reuse in the industrial facility, matching the level of contamination of the water, and the difficulty and expense of the treatment needed, to the potential end-use. Check the linked article from Industrial WaterWorld for a more detailed discussion.