I’m a water treatment professional
and I have been in the industry for 38 years. I’m also licensed by the California Dep’t of Health to treat potable water.
While electrical charges can come into play during filtration, a 0.2 micron filter will not be able to filter out the charged ions of materials dissolved in the water.
Chromium and other metal ions, will carry a positive charge, but are still way to small to be trapped by a 0.2 micron filter.
Dissolved material can only be filtered by a Reverse Osmosis membrane, and the pressure requirements will be very high.
Filters can remove biological contaminants such as spores, amoeba, bacteria, virus, etc. If there are other contaminants present, you won’t be able to filter them out.
lots of public sources
Lake Erie does have heavy metal contamination, but that stuff is on the bottom. Up top where you would draw you water to filter, it won’t be a problem.
Along your route you won’t be 5 miles from a source of public drinking water at any time. You will be able to refill your water containers at every town along the way and lots of spots in between. The canal water is probably more contaminated with petroleum products leaking from the boats on the canal than Lake Erie. Most of the towns along the Erie Canal have parks right on the canal with water available. You won’t have to filter it.
Bill
So waterdoc, how common are rivers or
lakes where the heavy metal content is so high that one couldn’t risk using it for a few days as a supply?
great responses
Thanks everyone for the great responses! It’s good to hear opinions from across the board on the subject.
It’s a cumulative effect
Heavy metals do not leave the body. So every time you ingest some you are increasing the amount in your body. Once you reach a toxic level, you have a major problem.
So there really is no safe level for just a few days. There are lots of other sources of heavy metals besides the rivers and lakes. Certain species of fish, shell fish, etc can all contribute.
Well, I would take a chance, because
I think it unlikely that I would accumulate enough of any particular heavy metal to affect me over a lifetime, just from using lake or river water on one trip. Now, I wouldn’t make a practice of it, but to get to see a particular waterway where there is no way to pick up water, or to carry enough for more than a few days…
I think you work in a job where you have to err on the conservative side.
Lake Erie
Cleveland is using it for drinking water, obviously with a bit of processing.
My wife had a chance to tour one of nearby water purification plants.
If I recall correctly the sequence goes as follows: sediment filtration, activated carbon, add chemicals.
Treat it
As a long time hiker I always practice treating my water no mater what. Unless it’s bubbling right out of the ground, chances are you may find nasties like Giardia. We had a co-leader break her own rule and drink directly from a so called clean brook only to become terribly sick. I paddle the Hudson and would not suggest drinking from it at all.
Gary