Water - Your Second Priority
You can survive only about three days without water. From a strictly survival point of view, water is one of the most important element for your body's survival. A person can lose all reserve carbohydrate and fat, and about half the body's protein without being in real danger. A loss of only 10 percent to 22 percent body weight as water is fatal. The amount of water lost from the body through urine, water vapor from the lungs, and through perspiration averages 2.5 liters per day.
It took five days for water to reach the super-dome after Katrina and weeks for water to be sent to New York and New Jersey after Hurricane Sandy. If you have an alternative water source (well, pond, spring and etc.), you still need an emergency water supply because they are susceptible to contamination. Under serious disaster conditions, no water can be presumed safe for consumption. Typhoid fever, dysentery, and infectious hepatitis are diseases associated with unsafe water. Water purification techniques may be effective in removing some, but not all contaminants from water. The only way to guarantee a safe water supply is to store it away yourself--before a disaster. The simple truth is that water supplies across the USA are rapidly deteriorating in both quality and safety.
Emergency Water Purification
We need to discuss the concepts of water purification. Water contains three things which must be revoved to become potable( drinkable). Water contains chemicals, debris and bacteria.
Chemicals such as oil, grease, gas, pesticides, acids, and fertalizers get into the water. The only way I know of removing chemicals is by using a carbon filter. When purifying water, it is best to start with chemical free water.
Debris can be removed using filtering techniques. If water contains debris, strain through paper towels, paper coffee filters, or several layers of clean cloth into a container to remove any sediment or flaking material. Keep filtering until the water is clear. You can make a lot of these filters which remove debris from the water. Be creative.
Bacteria is usually the hardest because you cannot see when this is done, however, it is very important. During a disaster you don't want to compound your problems by being sick or having to care for a lot of sick individuals. These individuals will not be able to help in survival. Fever, cramps, fatigue, diarrhea, nausea, dehydration, and general malaise can either sneak up on you slowly, or slam you all at once. During the manifestation period, being more than 10 seconds away from the nearest bathroom is often a bad idea. (Functional bathrooms may be in short supply during water or utility emergencies). It's easy to see that the best idea is not to take risks where you might be exposed to bad drinking or cooking water.
Water obtained from rivers, lakes and ponds, as well as from taps and wells, carries a considerable risk of contamination. Be unremitting in your efforts to maintain a high standard of safe water. Every member of your house must know the difference between safe and unpurified water containers. They must also know which source to use for which purpose.
You will need to dispose of dirty water somewhere. Do not allow members to pollute water supplies, your own or other people�s, by being thoughtless. Diarrhoea is usually caused by bad hygiene. It is imperative that hands are washed often.
First and formost, find the best source of water with as little "stuff" in it as possible. Wells are probably the best source followed by springs then surface water (rain water, lakes, ponds, etc).
Before treating the water to kill any organisms; organic matter, debris and silt need to be removed. Water may be boiled or chemicals added for sterilisation, but if sediment is not first removed the sterilisation process may be ineffective. Remember that simply clearing water does not sterilise it and that further treatment will be needed before it may be drunk.
It is best to use a pre-filter to remove large debris. Your regular filter will last longer. Some pre-filters could be simply cloth, a coffee filter, or a screen.
There are filters which purify water in all three areas. They need to contain carbon and 2-3 microns in filter size. The best filters are combination charcoal and ceramic. There are many places that sell camping filters in various sizes. In homes and RVs a combination of filters is usually used, i.e., you have a sediment filter, a carbon filter, and a UV bacterial killer. I consider the "black" Berkey the best filter available.
Bring water to a rolling boil and keep it simmering for 1 minutes for every 3,300 feet above sea level. Cover the pot to shorten boiling time and conserve fuel. To improve the flat taste of boiled water, aerate it by pouring it back and forth from one container to another and allow it to stand for a few hours, or add a pinch of salt for each quart or liter of water boiled.
Water can also be treated at below boiling temperatures, if contact time is increased. This process is called pasteurization. Solar pasteurizers have also been built that would heat three gallons of water to 65 deg C (150 deg F) and hold the temperature for an hour.
Use two drops of bleach or three drops of tincture of iodine per liter. Mix thoroughly by stirring or shaking water in a container. Let the water stand for 30 minutes. A slight chlorine odor should be detectable. If not then the dosage should be repeated and the water allowed to stand for an additional 15 minutes. Liquid bleach loses strength over time. If the bleach is one-year-old, double the amount. Two-year-old bleach should not be used.
Do not use granular forms of household bleach as they are poisonous. You may, however, use calcium Chlorate sold in swimming pool supply stores.
PDF on how to make Bleach for purification and cleaning using swimming pool shock treatment.
"Solar Water Disinfection" is an interesting method bacteria disinfection using Solar UV-A radiation and temperature (pasturaziation).
Distillation is an effective process and, what's more important, it can be done with a lot of improvisation. You can heat water with whatever is at hand: fire, electricity, mirrors, or whatever. You can use almost anything that holds water for a boiler, as long as you can direct the steam into a cooler. All you need is something that will just cool the steam down.
It does not remove substances that have boiling points at a lower temperature than water. Some of these substances are oils, petroleum, alcohol and similar substances, which in most cases don't mix with water.
The Bio-Sand Water Filter
One method of getting good clean water is a slow sand filter. Slow sand filters pass water slowly through a bed of sand. Pathogens and turbidity are removed by natural die-off, biological action, and filtering.
The bio-sand water filter is an innovation on traditional slow sand water filters, specifically designed for intermittent or household use. The filter can be produced locally anywhere in the world because it is built using materials that are readily available. It is simply a concrete container, enclosing layers of sand and gravel which trap and eliminate sediments, pathogens and other impurities from the water.
Makeup of a Biosand filter
Water is poured into the top of the filter as needed, where a diffuser plate placed above the sand bed dissipates the initial force of the water. Traveling slowly through the sand bed, the water then passes through a bed of prepared sand media and collects in a pipe at the base of the filter. At this point, the water is propelled through plastic piping encased in the concrete exterior and out of the filter for the user to collect. It should be used with a safe water container.
As with all slow sand filters, a combination of biological and mechanical processes removes pathogens in the water. When water is poured into the top of the filter, the organic material it is carrying is trapped at the surface of the fine sand, forming a biological layer or �schmutzdecke.� This biological layer matures over one to three weeks, depending on volume of water put through the filter and the amount of nutrients and micro-organisms in the water.
Four processes remove pathogens and other contaminants in the bio-sand filter:
- Mechanical trapping: Sediments, cysts and worms are removed from the water by becoming trapped in the spaces between the sand grains. Over time the spaces become smaller, enabling the filter to trap smaller particles sooner in the sand bed. The filter can remove some inorganic compounds and metals if they are attached to other materials or each other.
- Adsorption or attachment: Viruses are adsorbed or become attached to the sand grains. Once attached, they are metabolized by the cells or are inactivated by antiviral chemicals produced by the organisms in the filter. Certain organic compounds are also adsorbed in the sand and thus removed from the water.
- Predation: The microorganisms within the �schmutzdecke� or biological layer consume bacteria and other pathogens found in the water, thereby providing highly effective water treatment.
- Natural death: Food scarcity, less than optimal temperatures and a relatively short life span will cause pathogens to die off and become nutrients for other micro-organisms.
Some Interesting Water Purification links: