I've got and MSR filter pump combo (at least I think I do now that I think about it I haven't seen it for a while) which works pretty well. That being said I hike and bike in the same area you do and I've been known to drink untreated spring water if I can find its exit point and it looks clean. Stupid I know but so far I'm parasite free.
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The few, the proud, the likely insane, Metro-Atlanta bicycle commuters.