So years ago I remember being told by a park ranger that Virginia swamp water was a commodity for sailers visiting the new world. Apparently the decomposition of leaves in the swamp water created a sort of “swamp tea” killing bacteria and keeping the water fresh for a very long amount of time (important at sea). For whatever reason this has stuck with me, but I have never been able to find confirmation of this online. Was this a real thing, or was I misinformed?
I don't know if they drank it, but I can tell you with utmost certainty that it would NOT be healthy.
Stagnant water in swamps will always be a huge health hazard if ingestion is considered. That's literally one of the ways cholera develops. There is NO way decomposition of any plant leaves would turn water potable. It will be packed with various pathogenic bacteria and parasitic eukaryote organisms, from singlecelled ones to multicellular parasites.
Even regular boiling such water would not kill all organisms. Only sterilization or tyndallization would work, but those methods were unknown at the time, just like germ theory.
“Even though the average depth of the lake is only six feet, its unusually pure water is essential to the swamp’s survival. The amber-colored water is preserved by tannic acids from the bark of the juniper, gum and cypress trees, prohibiting growth of bacteria. Before the days of refrigeration, water from the Swamp was a highly prized commodity on sailing ships.”
https://dismalswampwelcomecenter.com/history/
OP here. After some more looking I was able to find this blurb on the website for the great dismal swamp in North Carolina. The website does not cite any sources though. I was told that this phenomenon was not local to the great dismal swamp, but so far this is the only reference of any kind I can find to drinking swamp water. I would appreciate any further confirmation.