How To Disinfect Water
Natural Gravity Water Filter Supplies
What you'll need:
1. A Container: something to use as a "funnel" to put your filter materials in such as an upside down soda bottle, a plastic bag, an inner tube, a large piece of bark cut and formed into a cone shape (birch works well for this), or even the leg of a pair of denim jeans tied off at the bottom.

2. A small piece of porous cloth (ie. cotton ball, piece of t shirt, bandana, etc.) , or a wadded up coffee filter or other porous material stuffed in the outlet that will keep your filter material in and keep it from clogging. It's not crucial that you include this, but if you have it, great!

3. Fine Sand or Silt. (the MOST important ingredient!)

4. Coarse Sand.

5. Grass.

6. Gravel or small pebbles.

Making A Natural Gravity Water Filter
In order to clear debris out of your drinking water, you can use a filter made from the natural materials above. There is no proper way to make this type of filter. The idea is to layer materials (sand, gravel, grass) in some type of container with a hole in the bottom. Then water is poured into the top and is filtered as it trickles through. The sand goes in the filter first, then the larger sand, then the grass, and then pebbles. As the water passes through the filter, sediment and debris sticks in the filter material and the clear water comes out the bottom.

For examples sake lets say that you are using an empty soda bottle as in the diagram at right. Chances are plastic will be around for centuries to come, so this is a likely scenario. Turn the bottle upside down. Stuff #2 (above) into the mouth of the bottle. Add a layer of #3, then a layer of #4, and so on, until your bottle is about 1/2 to 3/4 full. Than add water. The dirty water filters down and the clean water comes out the mouth of the bottle. Wha la!

Using Charcoal In Natural Gravity Water Filters
Some authors recommend using a layer of charcoal in natural water filters. Charcoal is used in many store bought water filters, and authentic charcoal is great at absorbing waterborne contaminants.

Use caution though, that you are using true charcoal as a filtering medium, especially if you are depending solely on it to filter waterborne pathogens out of water. Charcoal is not just bits of burnt wood or ash.

True charcoal is wood that has been burned without oxygen, either by being heated but sealed away from oxygen or, more commonly, by setting it on fire and then once all the wood is lit, cutting it off from the air. This can be done by smothering the fire with dirt, which keeps the wood from burning completely into ash. Most other substances in the wood are driven off, leaving a porous shape of almost pure carbon, lightweight and easy to transport. It can be used to purify water by soaking up impurities.

Some recommend using a layer of crushed, store bought charcoal briquettes in a water filter. Considering the following, I wouldn't recommend it.

According to Kingsford, their regular Sure Fire briquettes in the blue bag are made by heating sawdust and wood chips from mixed woods in special ovens with little or no air which removes water, nitrogen, and other elements, leaving almost pure carbon. Here's the problem. Once the charcoal is prepared it is then crushed and combined with anthracite coal, mineral charcoal, corn starch, sodium nitrate, limestone, sawdust, and borax. These additives act as binders, improve ignition, promote steady burning, and make manufacturing more efficient. The lime gives it that classic white ash so that you know when it's ready to cook on. So, as for cooking on? Sure. But not for water filtration.

Some recommend adding a layer of the activated carbon that you get at pet stores to your water filter. That is a great idea, if you happen to be near a pet store.

Even if water's been run through a natural water filter with charcoal from your campfire, if you suspect that there's a chance of the water source of containing waterborne pathogens, it should be boiled or chemically treated before drinking.

Diatomaceous Earth As A Water Filter
Diatomaceous earth is not poisonous, and is very safe. Diatomaceous earth is made up of the fossilized remains of tiny, aquatic organisms called diatoms. Their skeletons are made of a natural substance called silica. Over a long period of time, diatoms accumulated in the sediment of rivers, streams, lakes, and oceans. Today, silica deposits are mined from these areas.

Silica is very common in nature and makes up 26% of the earth's crust by weight. Various forms of silica include sand, emerald, quartz, feldspar, mica, clay, asbestos, and glass. Silica does not exist naturally in its pure form. It usually reacts with oxygen and water to form silicon dioxide. Silicon dioxide has two naturally occurring forms: crystalline and amorphous. Most diatomaceous earth is made of amorphous silicon dioxide. However, it can contain very low levels of crystalline silicon dioxide.

Currently, there are over 150 products registered for use inside and outside of buildings, farms, gardens, and pet kennels. Some products can also be used directly on dogs and cats. Diatomaceous earth products are registered for use against bed bugs, cockroaches, crickets, fleas, ticks, spiders, and many other pests.

There are thousands of non-pesticide products that contain diatomaceous earth. These include skin care products, toothpastes, foods, beverages, medicines, rubbers, paints, and water filters. The Food & Drug Administration lists diatomaceous earth as "Generally Recognized as Safe". "Food grade" diatomaceous earth products are purified. They may be used as anticaking materials in feed, or as clarifiers for wine and beer.

Diatomaceous earth (DE) can be used as a filtering medium to remove particulates and microbial contaminants from water. DE filters have achieved high removal efficiencies of a wide range of waterborne microbial contaminants without chemical pre-treatment of the water (Cleasby, 1990; Logsdon, 1990). There are different varieties of DE out there. If you are purchasing DE intending to use it for water filtration, be sure to buy the food grade type, which has no harmful chemicals added to it.

In commercial filters, called "precoat" and "body feed" filtration, a thin layer or cake of the fine granular or powdery filter medium is precoated or deposited by filtration onto a permeable material held by a porous, rigid support to comprise a filter element. The water to be filtered often is supplemented with more filter medium as so-called body feed. As water passes through the filter, particulates are removed along with the body feed filter medium.

DE filters also are capable of moderate to high pathogen removals (Logsdon, 1990). Eventually, the accumulation of impurities requires the removal of accumulated filter medium, cleaning of the filter medium support and reapplication of filter medium precoat to start the process over again.

Learn more about diatomaceous earth as a water filter in this publication.

Silver As A Bactericide
Silver was the most important antimicrobial agent available before the introduction of antibiotics in the 1940s. Silver has been used for at least six millennia to prevent microbial infections, as a fungicide, and for other medical purposes. It's been effective against almost all organisms tested and has been used to treat numerous infections and noninfectious conditions, sometimes with striking success. Silver also has played an important role in the development of radiology and in improving wound healing.

Because of its bactericidal abilities, silver is used as a water bacteriostat in carbon containing water filters (and in ceramic candle water filters). The silver is deposited onto the carbon granules to inhibit the growth of bacteria on the surfaces of these carbon particles. Such filters tend to leach out trace levels of silver into the effluent water. At these concentrations, the ingestion of silver has no detrimental effect on humans or animals.

The use of silver vessels to keep liquids pure longer has been known throughout history. Cyrus the Great King of Persia (550-529 B.C.), who established a board of health and a medical dispensary for his citizens, had water drawn from a favorite stream then "...boiled, and very many four wheeled wagons drawn by mules carry it in silver vessels, following the king "whithersoever he goes at any time".

Since ancient times silver vessels have been used in Mexico, the world's major producer of silver, to keep water and milk sweet.

Pliny, the Elder, in his great work, Natural History, (78 A.D.) reports in Book II, Section XXXV, that the slag of silver "... has healing properties as an ingredient in plasters, being extremely effective in causing wounds to close up..." .

In 1884 the German obstetrician, F. Crede, observing a relationship between the 20% to 79% of children in various institutions of the blind and the presence of maternal venereal disease, began the use of a 1% silver nitrate solution dropped into the eyes of newborns. Following the introduction of this treatment, the incidence of gonococcal opthalmia neonatorum dropped to about 0.2% . This prophylaxis became a state regulation in countries in Europe, North America, and elsewhere.

Hundreds of millions of children and adults have been exposed to silver either in clinical treatment or for drinking water sanitation since ancient times with no reports of toxic reactions. Nor has silver evidenced carcinogenic activity.

When colloidal silver (or silver particles suspended in fluid) is ingested and absorbed, however, silver is held indefinitely within tissue, particularly skin, eyes, and mucous membranes.

If taken in excess, this build up can cause a condition called "Argyria". This bluish tint to the skin is what gave Europeans the nickname "blue bloods".

By 1939, it became apparent that silver compounds administered by any route except the unbroken skin could produce argyria when used for a sufficiently long period of time, so the government turned away from silver, and turned to antibiotics instead, even though antibiotics kill the bad bacteria as well as beneficial bacteria.

According to the WHO, "On the basis of present epidemiological and pharmacokinetic knowledge, a total lifetime oral intake of about 10 g of silver can be considered as the human NOAEL(No observed adverse effect level) ".

The U.S. EPA has now established only a recommended Secondary Maximum Contaminant Level (SMCL) for silver because its effects are aesthetic rather than of health significance.

If you ingest colloidal silver for health purposes, be aware of Argyria, use in moderation and at your own discretion. Also keep in mind how effective silver is at killing bacteria with no ill side effects!

Credit For Content:
Centers For Disease Control and Prevention
Water Resources Division (Fort Collins, Colo.) of the National Park Service
The Book, "Wilderness Medicine" by Howard Backer
Men's Fitness
Beverage Institute For Health And Wellness
Purdue University
Utah State University Cooperative Extension
Arizona Cooperative Water Quality Extension
Huffington Post
WHO - World Health Organization
Diatomite Producers Association
Oregon State University
Department of Surgery - University of Cincinnati College of Medicine
Water Quality Association
Health Canada
Walkerton Clean Water Centre/Government Agency of Ontario
U.S. National Library of Medicine/National Institues of Health
Wisconsin Department of Natural Resources
Algae Detection and Removal Strategies for Drinking Water Treatment Plants By Detlef R. U. Knappe
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How To Disinfect Water
"Water makes up about 60-70 percent of our body and plays a role in virtually every function in the body — from keeping our blood flowing, our skin healthy and right down to our ability to blink our eyes," Wendy Bazilian, DrPH, RD and author of The SuperFoodsRx Diet says. "Water is our most important nutrient."

Most Americans have the luxury of going to a sink and with the turn of a knob they have access to unlimited drinking water. When you consider living off grid, wilderness survival or the possibility of a crisis situation, it goes without saying that you should be educated and well prepared in every way possible.

In the wilderness you have depend on your own safe drinking water procuring know-how, and keep in mind the fact that it can take some work and time procuring just a few sips of water. Considering how much water we need to stay properly hydrated, don't wait until thirst has set in to make procuring water a top priority.

Water Pollutants
You could find your next drink in a fast flowing river, a muddy puddle or a tiny pool of week old, bug laden rain water in a groove in a rock. No matter the source (or the flavor!) of the water, it is crucial to your survival that you drink enough or collect water when it's available, and you need to know how to disinfect the water.

You can filter out most of the dirt and bugs through a piece of cloth. Your main concern is actually the disease causing culprits you can't see with your naked eye, waterborne pathogens.

Human and animal waste are the main causes of waterborne pathogens (or microorganisms that live in water that can make you very sick). On this page you'll learn more about distinguishing safe drinkable water from water that should without-a-doubt be disinfected.

If grazing or farming is permitted on or near the land you are exploring, perhaps your best treatment option is boiling—or simply moving on to less-suspicious water sources.

Pesticides, herbicides and other toxins and pollutants associated with agriculture and urban development do not normally impact water sources found deep in wilderness areas. Recreational lands close to communities or farmlands may be more susceptible to such contaminants.

Microcystis From Blue-Green Algae
Cyanobacteria occur worldwide especially in calm, nutrient-rich waters such as freshwater lakes and rivers around the country. When in bloom, it secretes toxins such as microcystins, which can cause liver damage in animals including humans. Cyanobacteria are also known as blue-green algae, are so named because these organisms have characteristics of both algae and bacteria, although they are now classified as bacteria.

With the right conditions, its numbers can explode quickly, and are not only a threat to communities, but are a growing threat to backcountry water too. Normally, if water comes from an underground source, blue-green algae isn't an issue, or if the water is treated by water treatment facilities, this is sufficient to remove these toxins. However, when algae bloom is abundant, and the water source is a lake or pond, such as during the Toledo, Ohio scare in 2013, these methods can become insufficient. No one should ingest raw lake or pond water at any time, and bathing or washing food or dishes in contaminated water should be avoided.

Click the link for an informative paper called "Cyanobacterial Toxins: Removal during Drinking Water Treatment, and Human Risk Assessment' provided by the U.S. National Library of Medicine/National Institutes of Health.

According to the "Walkerton Clean Water Centre" which is a government agency of Ontario, Canada, the best options for removing mycrocystins are carbon based filters, which are 99% effective, and reverse osmosis water filtration, which is 99.9% effective. Boiling water does not remove blue-green algal toxins from the water. Due to the nature of blue-green algae toxins, using a solar still to distill the water isn't considered effective either.

ALWAYS treat any water that shows an algae bloom or harbors significant floating algae, but avoid it if at all possible. It's impossible to detect the presence of toxins in the water by taste, odor or appearance.

Waterborne Disease Causing Agents
It's possible that any water source on Earth could contain waterborne pathogens. The U.S. Environmental Protection Agency reports that 90 percent of the world’s water is contaminated in some way. The contamination by human and animal waste is measured in microns (aka micrometers). A micron equals one-millionth of a meter. (The period at the end of this sentence is roughly 500 microns wide.) The abbreviation for microns (μm) uses the Greek letter Mu.

Below is a list of the main waterborne disease-causing agents, from the largest to the smallest:

Examples: Cryptosporidium parvum, Giardia lamblia.

Size: Protozoa are single-cell parasites that range between 1 to 20 microns. Cryptosporidium (aka "crypto") typically measures between 4 to 6 μm; Giardia cysts range between 1 and 10 μm.

When symptoms appear: From 2 days to a few weeks. Individual protozoa are capable of causing infection.

Characteristics: Cryptosporidium and Giardia can both survive weeks, even months, in cold water. Crypto is a thick-walled egg (an oocyst). Its shell serves as a protective layer for the organism. In still water, the shell's weight usually causes the cyst to sink. The shell also boosts the resistance of Cryptosporidium to disinfectants such as iodine and chlorine.

Symptoms: Profuse, often watery diarrhea, vomiting, gas and intestinal discomfort. Most infections last 1 to 6 weeks; rare chronic cases can last up to a year. People with weakened immune systems need to be extra vigilant against contracting cryptosporidiosis.

Precautionary measures: Boiling, mechanical filtration/purification; UV light. Chemicals and halogens are effective against Giardia, but not always Cryptosporidium.

Examples: Escherichia coli (E. coli), Salmonella, Campylobacter jejuni, Yersinia entercolitica, Leptospira interrogans and many others.

Size: 0.1 to 10 microns.

When symptoms appear:  From a few days to a few weeks. The number needed to cause infection can vary widely. With Salmonella, for example, infection may require ingesting just a handful of organisms or several thousand.

Symptoms: Diarrhea and potentially prolonged intestinal discomfort. A more serious bacteria-caused disorder, cholera, is rarely encountered in the United States but is fairly common in some countries. It is usually associated with dehydration. It can result in death if not quickly treated.

Precautionary measures: Boiling, mechanical filtration/purification; UV light; chemicals/halogens.

Examples: Hepatitis A, rotavirus, enterovirus, norovirus.

Size: 0.04 to 0.1 micron.

When symptoms appear: From 1 day to several weeks.

Symptoms: Diarrhea, intestinal discomfort. Potentially a variety of other ailments.

Precautionary measures: Boiling, purification; UV light; chemicals/halogens (though contact time, ranging from 5 minutes to 4 hours, is required).

Warning Signs When You're Seeking Drinkable Water
If you're going to be in the backcountry, learn to discern backcountry water. Before deciding to drink untreated water, wilderness travelers should look for danger signs around a water source. Consider treating water if you spot any of the following cautionary tipoffs:

  • Water (particularly at lower elevations) near meadows or pastures where animals have grazed or near popular, established campsites.
  • Evidence of pack animal traffic or other domesticated animal activity.
  • Signs of sloppy human behavior or a prolonged human visit.

If no such signs are apparent, a water source (particularly any at elevations exceeding 7,000 feet) may offer some of the purest, most delectable water on the planet.

How Do You Know If Water's Safe To Drink?
Put simply, it's hard to. With the possibility of bacterial and viral contamination, chemical pollutants, and the potential for animal waste and carcasses upstream in other areas, it's imperative that you have the skills to properly purify drinking water. How you go about treating your water depends on your situation, but when in doubt, be safe rather than sorry.

If you don't have chemical disinfectants or filters, then boiling water is the way to go. (One reason why knowing how to build a fire is so important!) Boiling is a common and reliable way of disinfecting water.

*Remember, boiling, filtering, or chemically treating water can remove or kill microorganisms, but it will not remove all synthetic chemical toxins. (This is also the case when using a solar still)

Boil Your Water
Most germs die quickly at high temperatures. The CDC says that water that has been boiled for 1 minute is safe to drink after it has cooled. If no other method of water disinfection is available, very hot tap water may be safe to drink if it has been in the tank for a while. Boiled water will taste better if you put oxygen back into it by pouring the water back and forth between two clean containers. (This will also improve the taste of stored water)

•Boil water vigorously for 1 minute and allow it to cool to room temperature (do not add ice).
•At altitudes greater than 5280, boil water for 3 minutes or use chemical disinfection after water has been boiled for 1 minute. (The reason for the longer boiling time at higher elevations is that water boils at a lower temperature there, and giving your water a couple of extra minutes of boiling time ensures germs will be killed)

*Note that there is no benefit to exceeding these time limits. All that will do is cause some of your precious drinking water go up in steam.

Chemical Disinfection
Chemical disinfection is when you add enough of a chemical to your water to kill the germs, but still providing yourself with a safe drink of water. Tablets or packets of powder can be bought at camping stores to disinfect water. These usually combine chemical disinfectants (such as chlorine or iodine) with a substance that makes the water clear and improves its taste. Follow the instructions on the package closely—you may need to wait several hours until all the germs are killed.

In a disaster situation, The American Red Cross recommends that the only agent that should be used to treat water should be household liquid bleach. Other chemicals, such as iodine or water treatment products sold in camping or surplus stores that do not contain 5.25 percent sodium hypochlorite as the only active ingredient, are not recommended for use by the American Red Cross.

It's a good idea to try out products at home before using them in the wild to make sure you don't have any adverse reactions to the chemical you're using. It's recommended that you limit the time you will be using iodine to a few weeks.

The colder the water, the less effective the chemical is as a purifying agent. Research has shown that at 50' F (10' C), only 90 percent of Giardia cysts were inactivated after 30 minutes of exposure. If the water temperature is below 40' F (4' C), double the treatment time before drinking. It is best if water is at least 60' F (16' C) before treating. You can place the water in the sun to warm it before treating.

Chemically treated water can be made to taste better by pouring it back and forth between containers, after it has been adequately treated. Other methods include adding a pinch of salt per quart or adding flavorings (e.g., lemonade mix, etc.) after the chemical treatment period.

Iodine tablets
•Follow the tablet manufacturers' instructions.
•If water is cloudy, double the number of tablets.
•If water is extremely cold, less than 5° C (41° F), an attempt should be made to warm the water, and the recommended contact time (standing time between adding a chemical disinfectant to the water and drinking the water) should be increased to achieve reliable disinfection.
Note: Be sure the tablet size is correct for a liter of water.

  Tincture of Iodine - measure out your dose to water.
•If using tincture of iodine 2% solution, add 5 drops to a Liter or Quart of clear water.
•If the water is cloudy, add 10 drops per Liter or Quart. (Note: 20 drops=1 ml.)
•Allow the water to stand for 30 minutes before drinking when the water temperature is at least 25°C (77°F). Increase the standing time for colder water: (e.g., for each 10° less than 25°C (77°F), allow the water to stand for double the time before drinking it.

*Do NOT disinfect water with iodine if you have a thyroid issue, an allergy to iodine or if you're pregnant.

Chlorine Bleach
Clear water - Use 1/8 teaspoon or 8 drops of unscented bleach to one gallon (16 cups) of clear water. Mix well and wait 30 minutes before drinking.

Cloudy water - Use 1/4 teaspoon or 16 drops of unscented bleach to one gallon (16 cups) of cloudy water. Mix well and wait 30 minutes before drinking.

*NEVER mix bleach with ammonia or other cleaners.
*Always ensure adequate ventilation when using bleach.

Chlorine dioxide tablets are another disinfectant that now is available in some outdoor stores. This disinfectant has proven to be effective against pathogens, including Cryptosporidium, if the manufacturer’s instructions are followed.

Sanitize Containers Before Storing Drinking Water
1. Using unscented bleach, mix 1 teaspoon (64 drops or 5 milliliters) of bleach to one quart (32 ounces, 4 cups or about 1 liter) of water.
2. Pour this in a clean storage container and shake well, making sure that the solution coats the entire inside of the container.
3. Let sit for at least 30 seconds, then pour out the solution.
4. Allow to air dry or rinse with water that has already been made safe, if available.

Other Water Disinfection Methods
Use Water Filters
A variety of filters are available from camping stores. Most have filter sizes between 0.1 and 0.4 microns, which will remove bacteria from water but will not remove viruses. New “hollow fiber” technology can remove viruses as well. “Reverse osmosis” filters remove bacteria and viruses and can also remove salt from water, which is important for ocean voyagers.

Carbon components in filters and purifiers will remove some (but not all) organic chemicals (pesticides, herbicides, mine tailings, etc.) and inorganic chemicals (such as arsenic and mercury). Carbon often also removes objectionable tastes and odors.

Ultraviolet (UV) Light
Portable units that deliver a measured dose of UV light are an effective way to disinfect small quantities of clear water. UV light can kill bacteria and microorganisms in water because the energy emitted by the light is absorbed by the cells of microbes which prevents the cell enzymes from “reading” DNA. Without intact DNA microbes cannot reproduce. However, this technique is less effective in cloudy water since germs may be shielded from the light by small particles.

Solar Radiation
In an emergency situation, water can be disinfected with sunlight. Water in a clear plastic bottle, preferably lying on a reflective surface (such as aluminum foil), will be safe to drink after a minimum of 6 hours in bright sunlight. This technique does not work on cloudy water.

The Four Main Steps To Water Filtration
The entire filtration process generally has 4 main steps, coagulation, sedimentation, filtration and disinfection.

1. Coagulation: removes dirt, metals and other particles suspended
in water. Chemicals like Alum are added to the water that form
sticky particles called “floc” which attract the dirt particles.
2. Sedimentation: the combined weight of the sediment and
chemicals stuck together become heavy and sink to the bottom.
3. Filtration: smaller particles are removed as water passes through
a series of filters (sand, gravel, charcoal)
4. Disinfection: if necessary to kill bacteria or microorganisms found in the water, boiling or chemically disinfecting the water is necessary.
Copyright 2017-18
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