"The EPA reports that 90% of the world's fresh water supply is contaminated." (www.Katadyn.com) According to the World Health Organization 80% of all travel diseases are caused from contaminated water. Tap water, surface water (surface water is any standing or flowing body of water), ice cubes and even bottled water can all harbor unsafe bacteria, viruses, protozoans and agricultural chemicals. By consuming even the smallest drop of contaminated water, you can get Hepatitis A, E-coli, salmonella, cholera and many other diseases and sicknesses. Most water contaminates come from human and animal waste. They are spread by rain and run-off in surface water.

During a natural disaster, tap water may become undrinkable and when out backpacking, camping or hiking, we should certainly not trust any water we find, even if it looks crystal clear. Water purification will filter out chemicals, contaminants and pollutants from a water source, thus allowing you to drink the water that you find.

Boiling removes micro-organisms, but chemicals will remain in the water. If you are at sea level, boil water for 5 minutes. If you are at 4,000 meters above sea level, you must boil your water for 20 minutes to remove the bacteria. Remember that even the clearest water, such as in a mountain stream, can still hold bacteria, viruses and chemicals. Traces of agricultural chemical have been found in mountain streams.

Sanitizing water with the use of chemicals removes micro-organisms. Our cities' water supplies are sanitized using chemicals. Chemicals work best in clearer water. Typical chemicals used are chlorine gas, chlorine, chlorine dioxide, iodine, ozone, silver and ultraviolet. Even household bleach can be used to sanitize water. Chlorine is the most used chemical to get rid of water pollutants. Sanitizing can come in the form of chlorine dioxide tablets, which actually use oxygen, not chlorine, to clean water.

Filtration systems use ceramics, glass fibers or plastics to filter water. The filters are based on pore size which is the opening size of the holes in the filter. When looking to purchase a microfiltiration system, look for ones that have a rating of 0.3 microns or lower.

Activated carbon or activated charcoal is a very porous substance. In the water-filtration process, the fine granules absorb contaminants and pollutants. Activated carbon/charcoal is tasteless, odorless and non-toxic.

When picking water to purify, it is best to choose flowing water as opposed to standing/stagnant water. If you can find a water source that is odorless, clearer, rather than cloudy, and has little floating debris in it-the better. But you can still use water that is none of these, as sometimes you will not have a choice. If water is really dirty, let it settle in a big pot or bowl first or use a bandana, cloth or coffee filter to pre-filter out large pieces of sediment. When purifying water, it is best to use a combination of a filter method and a purification tablet.

Katadyn's Pocket Microfilter Endurance incorporates a hose and pump system that fills your water bottle straight from the water source. It utilizes a 0.2 micron depth silver-impregnated ceramic filter and is a compact size. The Pocket microfilter is good for camping, hiking and traveling.

Also using a pump and hose system is Katadyn's Vario. The Vario is adjustable for different water conditions and has 3 filter levels: glass fiber, a ceramic pre-filter and active charcoal. It produces two liters of drinking water per minute. This is a good versatile choice for all outside activities and for your emergency pack.

Katadyn's Base Camp is best used for planned camping trips or for at-home natural disaster emergencies. It holds 2.5 gallons of water and uses a 0.3 micron glass-fiber filter. Simply fill it up from your water source and hang it up, where a hose is used to dispense the filtered water.

The Exstream Purifier water bottle by Katadyn is best for short trips, hiking, biking, camping, or your emergency pack. It is a 26 oz. water bottle with a built-in filter. It uses iodine, activated carbon and a 1.0 micron plastic membrane filter.

Aquamira also makes a water bottle filter that holds 22 oz. of water. It utilizes a microbiological filter and activated carbon to remove contaminants.

The Frontier Filter from Aquamira is a necessity for your emergency and bug-out packs. This filter allows you to drink through a straw directly from the water source. It uses activated carbon and a filter and removes 99.9% of Cryptosporidium and Giardia bacteria such as E-coli. It will filter up to 20 gallons of water before you need to replace it.

Katadyn's Micropur MP1 purification tablets use chlorine dioxide which is effective against viruses, bacteria, Giardia and Cryptosporidium. One tablet will purify one quart of water.

Aquamira also has a water purification tablet. One tablet will treat one liter of water. It also uses chlorine dioxide. These tablets are good for light hiking, hunting, fishing, emergency kits, foreign travel and backcountry adventures.

We all know that traveling overseas can strike us with a case of Montezuma's Revenge, but even clear, colorless and odorless water can harbor pollutants. Most of us trust our city's tap water, but natural disasters such as floods, tornados, land slides and other disasters can taint city water. Whether you are traveling, hiking, camping or preparing your emergency pack, purifying water fit to should be one of your first priorities.