Finding Safe Water
What is safe?
This article delves into a very serious subject. Safe drinking water can be pretty simple and straightforward, but understanding the problem is important, so before we get into how to make your water safe to drink, here is some background on the problem:
Poor hygiene and unsanitary conditions are a common cause of disease and even death. Water-borne and fecal-borne contaminants are a potentially serious health hazard when outdoors and could ruin your trip.
The extent of your preparation will depend upon your circumstances: Where will you be hiking, boating or camping? Will there be potable (drinking quality) water, shower facilities or restrooms available?
While State parks and other park facilities may provide amenities, back-country hiking, camping, boating or even day hikes usually require that you provide your own.
The pristine character of a
wilderness environment often lures people into a sense of false confidence, believing that
sound hygiene is unnecessary and that all water is safe to drink.
(Shop Water Containers)
Know Your Enemy!
The bad guys:
There are two basic pollutants found in water, microorganisms and chemical compounds. Chemicals such as lead, mercury, pesticides, herbicides, fertilizers, silver and PCB's may be dangerous if they exist in extremely high concentrations or if you will be drinking the water for an extended period of time. Microorganisms, found in surface water and inadequately treated tap water, include:
- Protozoa (5-15 microns), such as Giardia, are the cause of many stomach and intestinal disorders both here and abroad. Giardia Lamblia is a parasite found in many water sources and spreads through human and animal feces. It is the most common water-borne illness in the US., but boiling, filtering, or chemically disinfecting water will kill this parasite. Symptoms appear in 10-21 days and result in a week or more of diarrhea, bloating, flatulence, and stomach cramps. Cryptosporidium Protozoa is a water-borne parasite that comes from feces of infected animals and humans. It is resistant to chemical disinfectant, but can be removed with any filter that eliminates Giardia or killed by boiling the water. It will cause explosive diarrhea and stomach cramps in 4-14 days and go away after 5-11 days of distress.
- Bacteria (.4-30 microns) such as E. Coli (traveler's diarrhea), Salmonella (Typhoid and food poisoning) and many others. Escherichia Coli (E. Coli) is a bacteria that thrives in fecal-contaminated water and is a major source of traveler's diarrhea.
- Viruses (.004-6.0 microns) such as Norwalk Virus (Rotavirus), Hepatitis A and Hepatitis E. Ocurring world wide, in water polluted with human waste, they can also be spread by sharing water bottles and utensils, improperly washing hands, passed easily from one person to another by hand and mouth, and by intimate contact. Stomach pain, nausea, vomiting, fatigue, and loss of appetite can show up within 2 days, and up to 50 days after ingestion depending on the virus. Severe cases may cause jaundice and dark urine. Hepatitis B produces similar, more severe symptoms but is transmitted almost exclusively by contact with blood and body fluids.
What You Can Do:
Choosing water for treatment
Choose surface water that is as clear of sediment and surface contaminants as possible. Aside from being unattractive and attracting microorganisms, sediment can clog filters, shortening usage life. When drawing from a stream, river, lake or pond, choose a site that is upstream from animals and in, or just downstream of, an eddy or slow moving water. (Sediment remains suspended in fast moving water.) If sediment is unavoidable, you can remove it before treating by allowing it to settle or by straining it through cheesecloth or a coffee filter.
Purify your filter before storing it so that microorganisms and other algae that are trapped in the filter do not grow and multiply. Soak the filter in a solution of 1 quart water with 10 drops of bleach for about an hour. This will not hurt those treated with silver oxide to retard bacterial growth. Read and follow all manufacturer's sUGGested cleaning and replacement guidelines to ensure the continuing effectiveness of your system.
Typical procedures include:
Backwashing - Detach the intake hose and attach it to the filter outlet. Pumping will send a "backwash" of clean water through the filter, loosening some of the accumulated material. The filter element must usually then be sanitized with a diluted bleach solution.
Scrubbing a ceramic filter- Remove and wipe off the ceramic cylinder or scrub it with a toothbrush to restore normal output. Those treated with silver oxide to limit the growth of microorganisms need not be sanitized afterwards, though it doesn't hurt.
Cleaning a surface filter - Remove the filter membrane and scrape/brush/flush it clean. Some makers recommend replacing the membrane when it turns gray. Sanitize after cleaning with a diluted bleach solution or by boiling.
While the term purifier is often used as a general category description, there is a difference between purifying your water and filtering or treating it. Purifiers must eliminate all microorganisms. (Shop Waterfilters)
By the time you have brought water to a rolling boil, all protozoa, bacteria, and viruses
will have been eliminated, and your water will be purified. The drawback to this method is
that it consumes time and fuel. Boiling will not improve the taste or remove chemical
Iodine and chlorine are often referred to as halogens and are effective in purifying the water. They remove all bacteria, viruses, and protozoa (except Cryptosporidium which is resistant to chemicals), but have no effect on metals, chemicals, and poisons. Water acidity, temperature, and the type and quantity of mineral or organic matter all impact the effectiveness of this treatment. Generally, the longer the exposure, the more effective the chemical. Iodine is common for emergency use. It is toxic, so should not be used for an extended period of time, and has an unpleasant aftertaste. Pregnant women and people with a Thyroid condition should avoid iodine altogether. Filters containing tri-iodine, bonded to a special resin matrix, prevent the release of iodine into the water and reduce the aftertaste. Chlorine is volatile and evaporates readily, so it is not recommended for backcountry use. To be effective in field use, there must be a "strong smell of chlorine to the water" after it is treated. Since Giardia is somewhat resistant to chlorine, it is important to treat the water as long, or longer, than directed. The water will taste of chlorine unless further treated.
Ultraviolet (UV) light technology
SteriPEN products use ultraviolet (UV) light technology to purify water, destroying more than 99.9 percent of bacteria, viruses and protozoan cysts such as giardia and cryptosporidia. The method has now been used for over one hundred years, and is currently used to purify drinking water by some of the largest cities in the world, including Seattle, New York (scheduled soon), Tempe, AZ and many others in North America, Europe and Asia. Ultra Violet light is also used by leading bottled water manufacturers to purify their source water. The EPA officially recognized the use of ultra-violet as a proven, viable technology in 1996: "Ultraviolet (UV) radiation has been found to be an effective disinfectant…. a useful small systems disinfection technology option." UV purification works as the ultraviolet energy emitted by the light is absorbed by the cells of the microbe, preventing cell enzymes from 'reading' its DNA. Without intact DNA, microbes can’t reproduce to make you sick. The process is simple but effective, destroying over 99.9 percent of harmful microorganisms. Purifying water with UV light offers many advantages. In addition to being safe and effective, UV light does not alter the taste, pH, or other properties of the water, and works without the introduction of chemicals to the water. (Shop SteriPEN)
This is the fastest easiest way to get clean drinking water when you're camping, hiking, trekking, boating, or traveling. Most filters strain water through a complex matrix that lets water pass, but traps harmful bacteria and protozoa. The filter construction and medium, along with pore size and water sediment, will dictate the frequency of cleaning or replacement. Most important is one that is easy to use, since you will need to treat about 1 gallon of water per day, per person. The new generation of ceramic filters can remove all pathogenic bacteria and protozoa, including giardia and cryptosporidia, and are easy to clean, even in the backcountry.
The newest technology to hit the outdoor scene is the advent of portable UV light systems. Using UV light to destroy the DNA of bacteria, viruses, and parasitic protozoa, these devices are small, efficient and highly effective. Proven to kill over 99.9999% of bacteria, viruses and parasites while meeting U.S. E.P.A. Guide Standard and Protocol for Testing Microbiological Water Purifiers. Taking less than a minute (about 48 seconds) to treat 16 oz. of wate they are faster than most other methods, plus these new devices weigh less than 4 ounces. Optional solar chargers mean no worries if you forgot to bring fresh batteries. Prefilters can be used if only murky or turbid water is available.
Why treat the water?
One sip of contaminated water can spoil your vacation, interrupt your work, or turn your camping trip into a disaster. It may even require emergency medical services. You can get ill from simply brushing your teeth or washing your utensils with bacteriologically contaminated water. Common sense dictates that water from any untreated source must be considered suspect and should be treated before drinking. When traveling in other countries, even bottled water sometimes contains contaminates. An estimated 50% of all travelers become ill due to the drinking water. Camping or backpacking in wilderness areas gives the impression of "safe", crystal clear lakes and streams, but one drink can quickly ruin your trip. The primary cause of illness is Giardia, but viruses and bacteria should not be overlooked. In an emergency situation such as an earthquake, flood or fire, it is often necessary to treat the water until it is certified to be safe.
How do you choose?
There are many treatment systems on the market today, from simple iodine tablets to systems that combine several filtration mediums with chemical treatment. Though weight and speed of processing are important, the primary consideration will be the safe and effective treatment of your water. To determine your needs, ask yourself the following questions:
- How often will you use it? For emergency survival or backup use, chemical treatment may be adequate. When trekking or backpacking, you will probably want a faster, more efficient method such as a filtration system.
- How much water will you need? There are single, one cup purifiers for traveling alone. If you are providing water for many people, consider high-volume pumps, gravity-fed filters, or purchasing more than one system.
- How long are your trips? You might need to clean your filter or replace it while traveling if you are away for an extended period of time.
- Where do you travel? The main concern in North America is Giardia which most filters will remove, but in third-world countries you may want to use a water purifier.
Filter type and construction
Pore size is measured in microns. (The period at the end of this sentence is about 600 microns.) Filters (1.0 - 4.0 microns) only eliminate larger microorganisms down to 1.0 micron. (Giardia can be strained by a filter of 4.0 or less.) Microfilters (0.2 - 1.0 microns) remove Giardia, other protozoa, and bacteria down to .2 microns, but this smaller pore size can result in quicker clogging and more frequent cleaning. Even a microfilter with a pore size of .2 microns will not remove all viruses. To "purify" the water a filter must also use a disinfectant, such as iodine or chlorine, to eliminate even the smallest viruses.
- Activated charcoal (Charcoal) is the only material that improves the taste and smell of the water and reduces the level of many pesticides, herbicides and chemical contaminants. When the carbon is compressed into a microfilter, it will also strain out protozoa and some bacteria. Carbon collects chemicals by a process called "adsorption", which is the adhesion of molecules to a solid surface. Regular replacement of the filter is necessary since it will no longer remove a material once the limit for that particular substance is reached. Regular cleaning is necessary or these filters will become a breeding ground for bacteria.
- Glass and other fibers are used to create surface / membrane filters. This single membrane is perforated with precisely sized holes that allow water through while blocking particles of a certain size and larger. The membrane is sometimes accordion pleated to increase the surface area. They are simple and effective, and some tend to clog quickly, though they are generally easy to clean and have a long service life.
- Ceramic cylinders of unglazed material are honeycombed with tiny passages. These are called depth filters since they are many layers thick and have a complex structure to trap undesirables. They are not highly affected by temperature, acidity or sediment, have the longest service life, and can be cleaned hundreds of times before needing to be replaced.
Filtration systems can process water at anywhere from a liter (1 quart) per minute to 1 gallon per minute. This is a convenience rating, but trying to pump faster than the recommended rate lowers the effectiveness of the filter.
Rules of the trail
- Carry out all garbage.
- Hike on marked trails, not across fragile alpine growth.
- Use existing campsites or sites away from water and trails.
- Respect and protect the wilderness.
- Tread lightly and only carry home photographs and memories.