It covers 71% of the surface of the earth, and makes up approximately 60% of the human body. This month’s Safety Minute discusses different ways to safely treat water for drinking when you are on an outing.
Treated Drinking Water
A constant supply of treated drinking water is essential. Serious illness can result from drinking untreated water. Protect your health, and don’t take a chance on using water of uncertain quality. Thermos jugs, plastic water containers, and canteens are all satisfactory for carrying water. Be sure water is dispensed into each person’s own drinking cup.
Safe Drinking Water
When possible, begin your trip with water from home or use approved portable water sources provided by the land manager. When these options are not available, streams, rivers, lakes, springs, and snow may provide a source of water, but they must always be treated by one of the following methods. All water of uncertain treatment should be treated before use.
The surest means of making your drinking water safe is to heat it to a rolling boil—when bubbles a half inch in diameter rise from the bottom of the pot. While this is a simple method, it does require time and fuel.
Chemical treatment consists of iodine or chlorine tablets that kill waterborne bacteria and viruses. These are simple, lightweight, and easy to pack. However, not all protozoa are eliminated by chemical treatment, and a waiting period is required for effective disinfection of drinking water. Micropur is a new product available for water purification.
In all cases, verify that the chosen method of chemical treatment meets EPA standards. Liquid chlorine should be used only in an emergency.
- Filter the water to remove as many solids as possible.
- Bring the water to a rolling boil for a full minute.
- Let it cool at least 30 minutes.
- Add eight drops of liquid chlorine bleach per gallon of cool water. (Use common household bleach; 5.25 percent sodium hypochlorite should be the only active ingredient, and there should not be any added soap or fragrances.) Water must be cool, or chlorine will dissipate and be rendered useless.
- Let the water stand 30 minutes.
- If it smells of chlorine, you can use it. If it does not smell of chlorine, add eight more drops of bleach and let it stand another 30 minutes. Smell it again. You can use it if it smells of chlorine. If it doesn’t, discard it and find another water source.
- The only accepted measurement of chlorine (or water treatment agents) is the drop. A drop is specifically measurable. Other measures such as “capful” or “scant teaspoon” are not uniformly measurable and should not be used.
Portable filters are handheld pumps that force untreated water through a filter media that traps bacteria and protozoa. Many include a purifying stage that will also treat viruses. While very effective, filters must be maintained according to the manufacturer’s instructions, and they are difficult to use with groups because of the time required to operate.
In addition to having a bad odor or taste, water from questionable sources may be contaminated by microorganisms, such as Giardia, that can cause a variety of diseases.
Source: The Guide to Safe Scouting