I am with you on boiling water if you want to be really sure about getting rid of the bad stuff. Some years ago I was privileged to participate in a caving expedition in China, far, far from commercially treated water. The custom then was to provide drinking water, which had been boiled, in large, Thermos-like containers. I was never sure what our water source was, but in one village, I suspect it was an open irrigation ditch. Alternatively, the source may have been a well which shared a common water table with said irrigation ditch.

I am sure the original water on this trip was as contaminated as anything any of us had ever experienced anywhere. But our drinking water came from the ubiquitous Thermos bottles. During a month of caving, the twelve of us Americans on the trip experienced exactly zero cases of Mao's revenge. As far as I am concerned, boiling is the technique if you really want to be pure (aside from the situation of arsenic and other metals contaminating your water) <img src="/forums/images/graemlins/grin.gif" alt="" />