Can anyone point me to any publicly available studies concerning the prevalence of Giardia in the water sources that the AT crosses, particularly in NC, TN and GA?

I have heard several locals/old timers say that if it runs out of a pipe (a spring presumably) then they don't treat it, others say anything out of GS National Park should be treated, a lot of folks say treat all water that doesn't run from a faucet or hose.

I would like to know if any real, current science exists to back up claims of Giardia.

Thanks.

PapaG