Hi Paul, not my expert field ...

Published by

Hi Paul, not my expert field but do think there may be some references from a South African perspective, did a quick search on the WRC (Water Research Commssion) website and found the following possible references to your subject matter, there may be more if you take the time to do a lit search, all downloadable free of charge

Hope this helps

Regards

Gary

http://www.wrc.org.za/Knowledge%20Hub%20Documents/Research%20Reports/KV%20352-15.pdf

http://www.wrc.org.za/Knowledge%20Hub%20Documents/Research%20Reports/2048-1-13.pdf

http://www.wrc.org.za/Knowledge%20Hub%20Documents/Research%20Reports/TT301-07.pdf