water purification?

I’m planning a multi-day trip down my local river (the Red Deer) next summer in my rec boat. Space is tight, so I’m considering carrying a water filter rather than 10 or 12 litres of drinking water. The folks at my local paddling store (who are more experienced that I am) were aghast at this suggestion and said they would never drink from the river.

Backpackers and mountaineers use filters extensivly in the bcak country, but I supopose the RD, like most N Amercian rivers is “urban.” That is, it carries lots of city and agricultural run-off. Does this make a difference when filtering?

Any perspectives on this? Hard data, as opposed to gut feeling, would be very helpful.

Purifier over the filter

– Last Updated: Dec-13-07 11:53 AM EST –

Do some research on both and you will find that a lot of filters and purifiers (added benifit of virus removal over filters) on the market DO NOT remove agricultural pesticides or heavy metals. I believe the Katydyn drip filters (with correct element) do and that their Pocket Filter (again w/correct element, and not Pur, etc now tagged Katydyn) may remove said agricultural pesticides and heavy metals, but I'd research to be sure. Check with your local E.P.A. or community H2o inspectors for this data also for the specific river you'll be potentially drinking from.

Check with these folks.
They may be able to answer questions about water quality.


You don’t want just a filter
If you think there will be a lot of pesticides, other chemicals, you want something with activated carbon and/or resin. The katadyn hiker pro is a start, but for ones that will really give you peace of mind, they get bigger and more expensive, like the First Need TravL Pure, $179.

What type of pollution
What is the pollution in the river? If it is chemicals from industry or farming, you may not want to drink even with filters.

I did a 2 week trip down the Columbia River this past fall, and everything we heard sounds similar to what you heard - don’t drink the water. A lot of industrial activities that put bad stuff (PCBs, etc.) into the water - all stuff that a filter would not take out. We did bring the filters just in case, but were able to get enough water sources (marinas and such) to refill every 3 to 4 days.

If you do filter - at least see if you can find a water source that is more clean to filter from. Like a creek that comes off of a mountain with no source of heavy metal contamination (no farms, no industry, etc.).

P.net column
from a while ago:


Doesn’t talk about ag and industrial contaminates however.

Filters etc.
Filters screen out particles down to the filter’s rated size. If the rating is 2 microns or so, it will remove most bacteria. If it has a submicron rating it will remove viruses too.

You cannot remove pesticides, herbicides, PCB’s, etc., etc., etc with a filter or a purifier. These chemicals are dissolved in the water at a molecular level and are not solid particles that can be removed by filtration. To remove these nasties, you need a membrane technology such as reverse osmosis that can effectively remove contaminants at the molecular level. There are no devices I know of that are available in a portable size and if there were they would be incredibly expensive.

Iodine won’t work either. It just kills bacteria and some viruses. Same thing for chlorine dioxide tablets. Many purifiers use a combination of filtration and an iodine-impregnated matrix to sanitize water, but their target is primarily living organisms.

Filters and purifiers work well when used with water sources that are relatively pristine to begin with. Removing complex organic chemicals requires technologies far more advanced than what you can buy off the shelf. If the river you mention is contaminated with industrial or agricultural chemicals, you would be putting your health at great risk by attempting to use a filter or purifier to produce your water. Find a way to carry it or find a different source such as a spring to filter from.

I wish I could be more specific…
I wish I could give you more info. I went to Madagascar ten years ago. I took a water filter with me and used it to filter my water the whole three week trip. I was drinking water from rivers where people bathed, pooped and anything else we can do in the water. It was a necessity. I never got any kind of illness, intestinal or otherwise. Sorry I can’t give you more info but the filter I used, whatever it was, seems to have done an adequate job.

See if you can find good data
For many rivers, the pollution levels are monitored and kept up to date. I’m not sure if yours would be one of them, but worth checking out. Realisticly, a couple days of low level pesticide residue isn’t going to do anything to you. Most pesticides that are in use now, break down withing a couple weeks. Hydrocarbon residue should be caught in the filter. I’d be very surprised if heavy metals were concentrated enough to be dangerous. Try and get some more info before you pack 3 gallons of water.