There's a water scare in Northamptonshire at the moment. Unhealthy levels of cryptosporidium have been found in a local reservoir, and this bug can lead to pretty serious diarrhoea. Both my village and workplace are in affected areas, and we are told we need to boil all our water before drinking it, cleaning our teeth, or even washing our dishes.
In my opinion, that sounds like a whole lot of work. I've got a garage full of beer, and there's plenty of good pubs around, so bugger the water; I'll have another beer.