There is a good article on water treatment/filtration in the current issue of the online NRS Newsletter. As you would expect, it is mostly focused on white water paddling, but it has some good basic information that would apply anywhere.

I work in water treatment and have a hard time solely trusting filters. You could have a microscope hole/crack/etc that makes you think the filter is working when in reality it’s doing nothing.

Redundancy is you’re best bet. Often end up boiling filtered water anyway when using it for rehydrating meals or tea/coffee. Feels like it’s rolling the dice drinking water straight from the filter.

JimEb: "I work in water treatment and have a hard time solely trusting filters. You could have a microscope hole/crack/etc that makes you think the filter is working when in reality it’s doing nothing.

Redundancy is your best bet. Often end up boiling filtered water anyway when using it for rehydrating meals or tea/coffee. Feels like it’s rolling the dice drinking water straight from the filter. "

If I was going to use the ultra violet path it would be behind a filter…

JimEb: "I work in water treatment and have a hard time solely trusting filters. You could have a microscope hole/crack/etc that makes you think the filter is working when in reality it’s doing nothing.


Redundancy is you’re best bet. Often end up boiling filtered water anyway when using it for rehydrating meals or tea/coffee. Feels like it’s rolling the dice drinking water straight from the filter. "

I have always had similar concerns and end up replacing the filter element in my gravity system often despite the cost. If I find myself in an area with heavy human usage or cattle, I will also double up with a sodium chlorite tab.

That may all be overkill, but it beats having gastrointestinal disease ruin a backcountry trip.

JimEb: "I work in water treatment and have a hard time solely trusting filters. You could have a microscope hole/crack/etc that makes you think the filter is working when in reality it’s doing nothing.


Redundancy is you’re best bet. Often end up boiling filtered water anyway when using it for rehydrating meals or tea/coffee. Feels like it’s rolling the dice drinking water straight from the filter. "

I respectfully disagree. There is a lot of scientific testing done by the manufacturers of said filters. If large numbers of people got sick despite using them, the manufacturers would be open to lawsuits. Plus their products wouldn't be very popular. Bottom line is that any method of water treatment has flaws (even boiling does nothing for chemicals or heavy metals), but as long as you're using the filter as intended, and replace it if you have reason to believe it might have been damaged, you will almost certainly be fine.

And even if there is a microscopic hole in the filter, it's not going to "do nothing" as you say. The vast majority of the water will still pass through the intact areas of the membrane, leaving contaminants behind. Am I advocating for using a damaged filter? Of course not, but it's still a lot better than drinking untreated water.

If someone is filtering water from a cattle trough on some remote PCT spot or off the jungle floor somewhere perhaps extra precautions are needed - I don't know. But since this forum is primarily about paddling the BWCA, Q, or points north in Canada, such duplication seems like serious overkill. It seems to me that a pin hole crack in a filter might let less bad stuff through than accidentally licking your lips after you dive under the water on a swim.

I had but one trip to the BW this summer in August and temps were in the mid 80's. On day on in camp my gravity filter failed me*, and my MSR stove was missing a part (user error). It took me like 45 minutes to boil and cool a liter on my twig stove and I was on day one of five, so I just took my Nalgene and 4 liter dirty water bag out to the middle of the lake and filled them up and drank straight from there for the rest of the trip. Maybe I was lucky, but I had not issues.

* 100% sure I backflushed, ran bleach solution, and dried after prior year's use as always. Only suspicion is mineral build up after 10 years of use, but that is an unproven theory.

Jaywalker:


* 100% sure I backlashed, ran bleach solution, and dried after prior year's use as always. Only suspicion is mineral build up after 10 years of use, but that is an unproven theory. "

While I really like my MSR gravity filter, I have found that I have to backlash every day or the flow is agonizingly slow and eventually not at all. After a 7 day trip, it needs replacing.

So are you saying you have used a gravity filter for 10 years before it finally gave way? What brand filter is that?

Platypus 4L system. I think I got about 10 years from it, with maybe 15 days average per year - guessing. Here is a thread last fall on similar issue.

Jaywalker: "Platypus 4L system. I think I got about 10 years from it, with maybe 15 days average per year - guessing. Here is a thread last fall on similar issue. "

Great thread and info, Jaywalker, thanks!

I’m talking just defects or damage. Yes, if filter bypass is small enough the pathogen concentration could be low enough where your immune system can promptly handle it. Could also be your source water is fairly clean. Also just because you drink some bad water doesn't mean you get violently sick. Might just have a sour stomach the next morning you pass off as last night’s fajita not agreeing with you. It’s just something to be aware of.

We manufacture RO systems for residual and commercial systems. Because of the potential of issues outside our control we do put a disclaimer on them saying to use only with microbiologically safe water. Intention of our systems is removal of mineral content anyway, to which they get routinely NSF tested and certified. In reality RO water is pretty dang pure, second only to DI water.

The first precaution is typically getting the water from the middle of the lake. The filter is the second precaution. I guess that could fail but that is near the bottom of the list of risks out there IMO. Boiling all the water would seriously affect the enjoyment of the experience, especially with a group.

I do the blow test on the filter after setting it up and bring tabs along in case it breaks. That's as far as I go.

plmn: "The first precaution is typically getting the water from the middle of the lake. The filter is the second precaution. I guess that could fail but that is near the bottom of the list of risks out there IMO. Boiling all the water would seriously affect the enjoyment of the experience, especially with a group.

I do the blow test on the filter after setting it up and bring tabs along in case it breaks. That's as far as I go."

+1

I saw it all working with the BWCA rangers the last two years.
One only filtered but only from the middle of cleaner lakes, he had a Steri Pen bit I never saw him use it. Most all the rest of us filtered. The last year we used gravity bags in camp and during portage clearing. That was real nice, we used hand pumps as backups.

I used my partners Steri Pen a couple times in the middle of cleaner lakes, it is a little hard to get used to, but I never got sick. He would dip out of the same water.

plmn: "The first precaution is typically getting the water from the middle of the lake. The filter is the second precaution. I guess that could fail but that is near the bottom of the list of risks out there IMO. Boiling all the water would seriously affect the enjoyment of the experience, especially with a group.

I do the blow test on the filter after setting it up and bring tabs along in case it breaks. That's as far as I go."

What is this blow test? I'm not familiar with that practice.

Platypus for the win.

Make sure you pack your clean bag on top of your pack so you can dip in the middle before you get into camp. Never had an issue and I’m on six years with this same Platypus filter.

Plus get one of these… they’re great for portaging.

scottiebaldwin: "Platypus for the win.


Make sure you pack your clean bag on top of your pack so you can dip in the middle before you get into camp. Never had an issue and I’m on six years with this same Platypus filter.

Plus get one of these… they’re great for portaging.

"

One of the BWCA rangers I worked with who had also done major backpacking, including the complete Pacific Crest Trail used one of these and I was always jealous.

Don't filter.... Dip and drink, and stay hydrated (most important).
Years of outfitting in the 70s & 80s I never saw a water filter.
All that has changed is liability by Forest Service and Outfitters.

NEIowapaddler: "

plmn: "The first precaution is typically getting the water from the middle of the lake. The filter is the second precaution. I guess that could fail but that is near the bottom of the list of risks out there IMO. Boiling all the water would seriously affect the enjoyment of the experience, especially with a group.


I do the blow test on the filter after setting it up and bring tabs along in case it breaks. That's as far as I go."

What is this blow test? I'm not familiar with that practice."

plmn: "

NEIowapaddler: "

plmn: "The first precaution is typically getting the water from the middle of the lake. The filter is the second precaution. I guess that could fail but that is near the bottom of the list of risks out there IMO. Boiling all the water would seriously affect the enjoyment of the experience, especially with a group.



I do the blow test on the filter after setting it up and bring tabs along in case it breaks. That's as far as I go."

What is this blow test? I'm not familiar with that practice."

"

Thanks!

Stumpy: "Don't filter.... Dip and drink, and stay hydrated (most important).
Years of outfitting in the 70s & 80s I never saw a water filter.
All that has changed is liability by Forest Service and Outfitters."

The overall risk might be different now…up until the late seventies motors were allowed in much of the area, beavers were actively trapped in the area…I don’t think anyone runs a wilderness trap line in the area anymore. Beavers being the biggest vector for contamination, an increase in population might make exposure more likely. Although if you are always on big deep lakes, the center of the lake should be just as safe…sometimes ya get stuck on a small lake or ponds though.

I think the same as you but now I do trips where other peoples children are along and adding a filter is a small inconvenience that adds less risk. If a kid gets sick, I can still sleep at night knowing we did everything possible and as you said…liability :)

T