Where can I find International Water Reuse Standards and Regulations ?

Hello everybody, Anyone know where I can find some Standards and Regulations about Water Reuse for agriculture and industries? I need water reuse standards for European, Middle east and Asian regions for my new project. In Brazil we only have regulations for agriculture and secondary water reuse. Industrial regulation is taking so long to get approved from governmental agencies.... I would like to thank you all for your kind attention.  Warm Regards!  Léo.