o CO £ £ 3 CO CO 11 551 > "O o « o c: c ±; '> cd c c ra Z> UJ < oU.S. GOVERNMENT PRINTING OFFICE: 1 980 — 680-1 A9 United States Environmental Protection Agency WATER v-/EPA DON'T DRINK THE WATER Until Have This ... ------- During the past few years, increasing numbers of campers, backpackers, anglers and hunters have been stricken with waterborne diseases because they drank water straight from streams, springs or lakes. Even though the water appears to be sparkling clean and pure it may contain microorganisms which cause disease. One particular organism common in many waters is Giardia /amb/ia. This parasite has been found in many wild and domestic animals; therefore, it can be present in wilderness areas regardless of whether there are humans in the area. The organism is transferred between animals and humans by means of excreted fecal material. If the infected animal or human defecates in or near a stream the organisms are then spread through the water. Beavers are very prevalent in the transmission of Giardia. Their aquatic habits insure a steady supply of the parasites to the water. Since the organisms can survive in water for at least two months, the problem is not limited to particular times of the year or sections of streams. Drinking water containing a few of these parasites causes giardiasis, a severe gastro- intestinal disorder which results in acute diarrhea, vomiting and loss of appetite. These conditions can result in serious dehydration of the body which can be a problem if you are in the wilderness. "An ounce of prevention is worth a pound of cure," and in the case of giardiasis the best prevention is not to drink naturally occuring water regardless of how pure it looks. This means that you must either carry all your own water or disinfect the water before drinking it. Water Disinfection Methods Of course, carrying your own water is not a good alternative if you plan to be out for any length of time, but several methods are available for making water safe to drink. These are boiling, homemade disinfectants and commer- cially prepared disinfectants. The use of commercially available filters for water purifica- tion is discouraged since most of the devices do not filter out particles small enough to eliminate Giardia, or other smaller organisms. Boiling kills Giardia, bacteria and viruses. Research has shown that at sea level, boiling water for one minute effectively eliminates these hazards. However, at higher altitudes water boils at lower temperatures. When you are in the Rocky Mountains, for instance, longer boiling times should be observed, (i.e., 15 minutes at 10,000 feet). Disinfectant Quantity per Quart of Water Waiting Time Before Drinking Chlorine Tablets 5 Tablets 30 Minutes* Household Bleach 4 Drops 30 Minutes Iodine Tablets 2 Tablets 20 Minutes* 2% Tincture of Iodine 10 Drops 20 Minutes Saturated Iodine Not Recommended *When using tablet, the waiting time begins after the tablets are dissolved. The table below lists the various disinfectants available and the recommended dosage per quart of water. The use of saturated iodine (made by dissolving iodine crystals in water) is not recom- mended because it does not kill all of the Giardia organisms in cold water. Remember, although it may be inviting to dip a cup of water from a clear, fast flowing mountain stream, you may regret it later. The best rule to follow is to disinfect all water when in the back country. ------- |