The Gear Junkie: PUR Purifier of Water

PUR markets its latest water-purification product as a "mini water
treatment plant in a packet." Indeed, the pragmatically named PUR
Purifier of Water employs the exact chemical process as used in many
municipal water-treatment plants around the Western world.

Developed more than a decade ago by Proctor & Gamble, and used in
municipal as well as humanitarian applications, the process introduces
iron sulfate and calcium hypochlorite in a powder form to water
tainted with sediments and microorganisms. Unlike iodine or other
typical treatments used in the outdoors, the P&G process pulls all the
gunk in water together, coagulating nasties including cysts, microbes,
viruses and bacteria into clumps you can then filter out.

As a two-step process, calcium hypochlorite, a bleaching agent,
kicks in after the initial coagulation to kill off any remaining
gastrointestinal disrupters. The final result is water that's 99.99
percent pure, according to data from PUR parent company Reliance
Products, which needed U.S. Environmental Protection Agency approval
before introducing the chemically-potent product to the consumer
market earlier this year.

Scott Mitchell, a spokesman for Reliance, explains the iron sulfate
coagulation process by referring to the chemical reaction as a "dirt
magnet." "It reacts in the water and pulls everything in suspension
together in clumps," he said.

I tested the product with tannin-tainted water from a stream in
northern Wisconsin. Flowing from the depths of the Chequamegon
National Forest, the water was dark brown and speckled with sediments
and microorganisms swimming free.

Working with the PUR Clean Drinking Water Kit -- a $28.99
do-it-yourself water treatment plant that includes the PUR chemicals,
stir sticks, filtering cloth and containers -- I mixed and stirred
and followed directions for 45 minutes. I watched the clock for timed
waits while chemical reactions triggered. Slowly, the brown water
began to turn clear, with sediment clumping together in a disgusting
reddish mass at the bottom of the container.

Filtering the flocculent -- the technical term PUR uses to describe
the clumped putridity -- was a pain. I worked with a friend near our
campfire for 20 minutes, pouring the water through a cloth that kept
clogging up. The cotton caught the flocculent fine, though it allowed
only a small stream of clean water through its tight fabric weave and
into the vessel below.

Another annoyance: The collapsible buckets that come with the Clean
Drinking Water Kit have small openings, making pouring and filtering
slow. The foldable containers are difficult to clean, too, as deep
accordion creases in the plastic catch and hold flocculent that's then
nearly impossible to wash out.

But after some struggle, the PUR method yielded water that was
indeed quite clean. In front of my eyes, the final product transformed
from a container of gloppy river water into a gallon of sparkling,
crisp H2O that seemed siphoned from a spring.

PUR sells two Purifier of Water products, including the kit I tested as
well as a $14.99 package that has chemicals for six treatments and a
cotton filter clothe, though no containers.

While the process is cumbersome, Purifier of Water is a superior way
to clean large quantities of suspect liquid. My main beef was with the
Clean Drinking Water Kit's containers. The chemical reaction in dirty
water was amazing to watch, and the mix-and-stir process is easy to
follow and manageable if you have a half-hour or so to work with your
water in camp. Next time, I'll use a custom configuration of buckets,
vessels and a larger cotton cloth to speed the mixing and filtering

Compared to pumps and other traditional chemical treatments like
iodine, PUR's system is purportedly the most thorough. There is almost
no smell or chemical aftertaste, just hydrogen and oxygen mixed and
pure, sloshing, swirling and ready to drink in a bucket below.

-- Stephen Regenold writes The Gear Junkie column for several U.S.newspapers; see for video gear reviews, a daily blog, and an archive of Regenold's work.

Posted on April 4th, 2008

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