The health concern with irrigating edibles with greywater is the potential to ingest a pathogen from someone else whose germs are in the greywater. The health rule, and rule of many greywater codes, is you can not irrigate
root crops or allow greywater to touch the edible portion of the plant. If the bamboo shoots are above the
water level and greywater would not touch the part you were going to be ingesting it
should be fine to eat the bamboo.
Some people wonder about the potential health affects of chemicals compounds entering the plant from soaps in the greywater. What is important to keep in mind is that in a residential greywater system, the soaps in the water were directly touching someone's skin and being absorbed directly into the body. If someone is worried about the health affects of the
soap going into food through a greywater system they should definitely not put that product onto their skin! Hope this makes sense.
Co-founder: Greywater Action, www.greywateraction.org
Author: Greywater, Green Landscape, and The Water-Wise Home: How to Conserve, Capture, and Reuse Water in Your Home and Landscape