I wouldn't advise using the ...

I wouldn't advise using the grey water untreated like previous comments, however, there are good filtration systems. Not to turn this into a sales pitch but we have a system developed utilising organic filters that treat most of the nasties. This is in progress with United Nations and UNICEF currently.

I would be more than happy to have further dialogue with you. Let me know if you this would be of interest. Thanks in advance.