Check out Cape Peninsula University in Cape Town, South Africa. They have a Community Water Supply and Sanitation (CWSS) unit. See www.cput.ac.za/cwss. I've worked with people from there, they're really great. Good development focus.
UNESCO-IHE in The Hague Netherlands also provides education on watsan, I think it's more technical. But am not sure, do not know anyone there (did an online course with them on ecological sanitation though, which was great).
Good luck.