Clear water: The murky truth.

Byline: MIKE STAHLBERG The Register-Guard

Dipping a Sierra cup full of glacier-cold water from a mountain stream once was a cherished part of the wilderness experience. Not anymore.

Just ask Kraig Lindelin, a wilderness crew supervisor on the Three Sisters Wilderness Area in the Cascades east of Eugene.

"I've had giardia, and that's not a fun thing," Lindelin said. "So now I'm real careful to make sure the water I drink has been treated."

Judging by the number of portable water filters and purifiers that have hit the market in recent years, treating drinking water has become something of an obsession among hikers, backpackers, mountain bikers, kayakers and anyone else likely to work up a thirst in the outdoors.

The Eugene outlet of Recreation Equipment Inc., for example, devotes an entire display section to water-treatment devices and products - most of which couldn't have been found in an outdoor store just a dozen years ago. And that store carries only a fraction of the brands and models that can be purchased elsewhere or over the Internet.

The growth in product offerings is fueled by increasing public awareness of the fact that cool, clear water isn't necessary clean, or safe.

Even water from burbling mountain brooks and springs can carry disease-causing bacteria, protozoan cysts and viruses that are invisible to the naked eye.

Lindelin knows that from first-hand experience. He was working on Horsepasture Mountain five or six years ago when he ran out of the treated water he carried with him from camp. He spotted a spring and thought it would surely be safe to slake his thirst with water coming right out of the ground.

A week or so later, he was battling the effects of giardia lamblia, a protozoan cyst spread through animal and human waste. Often associated with beavers, giardia is also present in the waste of river otters. (Other common water-born pathogens include cryptosporidium, another protozoa, and campylobacter jejuni, a bacteria.)

"I was feeling gassy and sickly - it really makes you weak," Lindelin said. "You think you've got the flu. If you rest for a couple of days, it seems to go away, but then when you exert yourself again. it comes back with a vengeance."

Lindelin said he couldn't shake the disease until he finally saw a doctor who put him on a seven-day drug treatment that made him feel sick all over again.

While admitting nostalgia for the dip-and-sip Sierra Cup days he used to enjoy while hiking with his father, Lindelin said he's now unwavering about using the Katadyn Pocket Filter that the Forest Service issues to its wilderness crews.

One of the first on the market, the Swiss-made Katadyn is heavier and more of a chore to pump than some of the newer and lighter treatment devices.

Among those are some that promise almost as much convenience as the old Sierra cup.

These are plastic squeeze bottles with filter or purifier units connected to the drinking spout. The user simply dips the bottle into lake or stream to fill it, screws the lid and attached filter assembly back on, and starts squeezing and sipping.

Outdoor enthusiasts have four basic options for treating water before they drink it - heat, chemicals, filters and purifiers.

Heat treatment is the old standard. Simply boil your water long enough to kill any bacteria and viruses that may be in it. It's time- and fuel-consuming, and the resulting drink might not be not all that refreshing on a hot summer day.

Chemical treatment with iodine or chlorine is "the most basic option," according to Robbie Igoe of the Eugene REI store.

"Just drop a tablet or some liquid solution in the water, mix it and let it sit for a little bit," said Igoe, although you probably want to run the water through a fine-net cloth first to get the sediments and particulates out.

The cost of chemicals is minimal - $5 will get you enough Potable Aqua or similar product to treat 25 gallons of water. The disadvantage is that iodine or chlorine "can leave a funny taste in the water," Igoe said. Potable Aqua, however, offers a second tablet that removes the taste and discoloration caused by the purification pill.

Water filters physically remove impurities by forcing water through material with openings too small for the impurities to pass through. The filtering medium can include paper, ceramic and even charcoal.

Paper-based filters provide a faster flow rate and are less expensive to replace, Igoe said, but ceramic filters last longer because they can be cleaned and re-used. Replacement filters can be purchased, but they usually cost a little more than the original price for the whole unit.

Costs start at about $25 and go all the way up to $200, depending on the type of filter, the rate at which it's designed to treat water and the overall sturdiness of the unit. (The manufacturer of the Katadyn filters used by the Forest Service, for example, claims its ceramic filter can be cleaned 300 times and treat up to 13,000 gallons, while some of the squeeze-bottle makers claim their paper cartridges will treat 200 gallons before needing replacement.)

Water filters will remove protozoan cysts and bacteria. However, they will not removes viruses, such as Hepatitis A, which are too tiny to be trapped by mechanical filters.

Mechanical water purifiers differ from filters in that they do treat viruses, as well as protozoan cysts and bacteria. Most purifiers work on the same principle as a water filter, but they also render viruses inactive by exposing them to an iodine resin during the filtering process. Other varieties of purifiers use an electrostatic charge in the filter medium to "capture" viruses.

Water purifiers range from about $30 to more than $500 (for a high-volume "expedition" model). Exstream makes squeeze-bottle models of purifiers, including one designed to clip on to a mountain bike, for less than $50.

In addition, a variety of "accessories" are available - including inexpensive "pre-filters" designed to keep the worst sediment from clogging up the main treatment unit.

Factors to consider in purchasing a water treatment unit include where and how much it's going to be used.

An inexpensive filter is probably adequate for the recreational backpacker who takes a couple of trips per year, especially if they visit places where clear water abounds. Someone who regularly spends long periods of time in the backcountry, however, probably should seek out a model that's easy to clean in the field, as they're more likely to eventually find themselves treating turbid water.

And these units will definitely treat muddy water, Igoe said.

"I've been in the Sierras and had to get my water from actual mud puddles," he said.

No matter what kind of treatment system you use, he said, "the most important thing is to make sure not to drink out of the container you transported the water in before you filtered it. Probably the biggest mistake people make is not realizing they've contaminated a container and then putting filtered water back into it."

REI offers these other tips to maximize the effectiveness of water treatment devices:

Avoid filtering water in an area where human or animal activity is obvious.

Try and filter water taken from still, clear sources. Many microorganisms tend to sink to the bottom of still water, but a turbulent stream keeps them suspended.

Discard the first few streams of output from your filter. They don't taste as fresh.

Rather than filter directly from the stream or lake, put water in a pot and filter from that. This will give you a chance to prevent clogging by examining the water before you pump it through your filter. If the water is cloudy, let it sit in the pot for an hour or so, then skim the clearest water off the top.

CAPTION(S):

Robbie Igoe, an employee of the Eugene REI store and an avid hiker, knows the value of a good water purifier.