healthy lifestyle doesn't have to stop after holiday?! That will and does make a big difference on long term health
parts of UK including midlands and north east England are also unfortunate enough to receive fluoride treatment and all the other contamination
http://www.bfsweb.org/onemillion/09 One in a Million - The Extent of Fluoridation.pdf . I wonder why London doesn't get any?! I am sure they still pull enough of antibiotics, antidepressants and pesticides from Thames though.
Tap water may be safe in places with deep underground water reservoirs and particularly in mountainous areas otherwise I wouldn't touch it now. Bleach makes it taste and smell rancid, destroys flavour of good quality teas, but that is the least of your worries...