During one of those days, we took a spur-of-the-moment hike up Thunder River and crawled into Thunder Cave, the gaping hole in the redwall limestone where the waters of Thunder River flowed out from some unseen source. Having left our water bottles behind at camp, we cupped our hands into the rushing waters coming out of the cave and drank freely of the cold, sweet water.
About two weeks later, that moment came back to haunt all four of us. I felt it first – that queasy feeling when you know that your digestive system is just not right. Then my husband came down with it. First we thought it was food poisoning, but a call from our friends who had accompanied us on the Thunder River trip confirmed that they, too, had come down with the illness.
And it got worse. Our intestines were tied up in knots. Our stomachs churned. We felt queasy, and so very tired. We couldn’t eat, and when we did, it was a mad rush to use the one bathroom in our house. It was one of the most miserable illnesses of my life, and having a spouse in the same condition made it even more miserable.
A trip to the doctor confirmed our fears: we had picked up the parasite giardia, most certainly while drinking the unfiltered water from Thunder River.
Giardia is a one-celled, microscopic parasite that, once ingested, lives in the intestines of animals and people. It is found in every region throughout the world and is recognized as one of the most common causes of waterborne illnesses. In contract to many other bacterial illnesses, where thousands of organisms must be ingested before the illness sets in, giardia only takes one ingested cyst to get the misery going.
Giardia can be found in any untreated water supply, from a cold mountain stream to a spring emerging from the redwall limestone. When taking water from any untreated water source, it is important that your water be filtered or treated to reduce your chances of acquiring the nasty parasite. Water purification tablets or a water filter, when used properly, will eliminate the giardia parasite, as well as other nasty critters that may be swimming unseen in your drinking water.
The simplest way to kill giardia in your water is to boil it. Bring your water to a rolling boil and the parasite will be killed. But boiling water is inconvenient, does not remove the sediment in the water, uses up fuel, and forces you to carry a stove. Also, if you’re up in the high country, you need to give the water a little extra boiling time.
Chemical tablets used to purify water take up little space, cost little, and are very effective in removing giardia. (Cryptosporidium, another nasty parasite, is much more resistant to iodine and chlorine treatments). Potable Aqua and Polar Pure use iodine, Aqua Mira uses chlorine dioxide. While I’ve found that Potable Aqua, even with the neutralizing tablets, leaves a faint iodine flavor, water treated with Aqua Mira really tastes like water. Tablets are convenient and easy to carry as a backup supply in your first aid kit, or even in the glove box in your car in case of an emergency.
There are water filters, and there are water purifiers. Water filters remove protozoa (such as giardia) and bacteria from water by forcing water through a filtration system. Purifiers do the same plus eliminate viruses by chemical means (such as adding iodine) or by an electrostatic charge.
When choosing a water filtration system, consider a few pointers:
1. Look for an absolute pore size of 0.2 microns. This is the industry benchmark for the smallest filtering capability. Make sure it is an absolute pore size, not nominal.
2. Check to see how many parts the water treatment system has, since many will have to be cleaned, replaced or maintained on a regular basis.
3. Find out how many liters of water can be filtered through the system before the filter needs to be changed.
4. Take a look at the pumping system. A lever-action type of pump handle may be easier than a straight pump handle.
Water treatment systems range in price from under $10 for tablets to several hundred dollars for water purifiers that use an electrostatic charge to eliminate protozoa, bacteria and viruses. While viruses are not as common in water supplies in North America, international travelers should choose a water purifier to eliminate possible viral contamination in foreign countries.
While my most vivid memory of my first hike down to Thunder River is one of sparkling water cascading down the river’s short course into Tapeats Creek, and the lush green among the red canyon walls, my second most vivid memory of that hike is the pain I felt about two weeks later when the giardia protozoa invaded my intestinal system. As a side note, the prescription Flagyl used to combat giardia makes you feel just as lousy as the bug itself. The entire episode rendered me moaning and useless for almost six weeks.
The image of a hiker drinking water from a “pure,” babbling brook looks great in magazines, but is no longer accurate in the real world. Everyone who goes into the backcountry should carry some sort of water treatment system, whether simple tablets or a full-fledged purification system. It’s worth the weight and worth the investment.