There was some concern that F&M virus could remain in cave water for in excess of 6 months. Because of this concern a discussion document was written, see:-
http://www.caving.org.uk/news/fmdv_in_cavewater.html
In this document it states that the virus is very intolerant to changes in temperature and pH.
A critical factor for the virus is the pH, as either side of the pH7 'indefinite lifetime' region, the virus quickly dies when exposed to acid or alkali conditions. This is actually the basis of the agricultural disinfectants approved by MAFF.
So what is likely to be entering our water courses are very weak alkaline or acidic solutions. If this is the only component of the disinfectant, then there should be no concern re our rivers. However, we don’t know what other components are present as MAFF are only concerned with the pH of the disinfectant. There is a hyper link on the MAFF website "disposing of disinfectants" which throws up an “error occurred message” on the Environment Agencies website. I have asked their web master to email me the correct internet address which deals with the disposal of disinfectant relating to Foot & Mouth. If I get a reply I’ll post it on this thread.
John