Water For Survival

The importance of adequate water in a survival situation.

Besides oxygen, water is by far the most important nutrient for the human body. Humans cannot survive more than several days without adequate amounts of drinking water. Generally in our normal environment, an average person requires a minimum of two quarts of clean water per day. In a hot environment, more water is required, even up to a gallon a day. Surprisingly, very cold environments can also dehydrate your body very rapidly.

There are many emergency situations that can cause a disruption to our supply of potable drinking water including hurricanes, tornadoes, earthquakes, fires, floods and other natural disasters. These events can severely affect the water delivery infrastructure.

After, Hurricane Sandy, public officials declared a “Water Emergency” and issued “boil water alerts” because municipal source water was contaminated by sewage run off and power outages shut down the water treatment plants. The water became contaminated with disease causing microorganisms, and therefore was “Non-Potable”. This is a typical condition of drinking water in many countries. Thousands of people die everyday of diarrhea due to waterborne disease. It is difficult to conceive of this condition existing in the U.S. for a prolonged period of time, however, in the Preparedness Community it is a one of it’s priorities to have short and long-term potable water.

There are many procedures published for producing potable water for short and long-term storage, but until recently there has been no research backed definitive protocol for all aspects of emergency water preparation. There are now several government publications available that are in depth reviews of personal filtration devices, and protocols for producing potable water. These stricter standards and protocols assure that military personnel and others have access to safe drinking water from any fresh water source that may be available to them when deployed or in the field.

Using an individual water purification device (IWPE) is part of a filtration protocol that provides microbiologically safe water to protect the solider from acute microbial health threats. When selecting a filtration device, it should meet minimum performance standards of 6 log reduction (99.99999) of bacteria, 6 log reduction for viruses(99.99%), and 3 log reduction for protozoan cysts(99.9%), typically Giardia and cryptosporidium. Some IWPD manufacturers test their devices, however, in the absence of test data, it’s important to select a device that can at least meet some of the standards and combine filtration with disinfection procedures to achieve microbial free water.

Using filtration alone without a proper disinfection protocol when on the go or in place may lead to an acute infection that could prove fatal. The following multi-stage disinfection filtration processes are therefore presented to the reader as a guide to providing short and long-term safe potable drinking water.

One of the first steps in the process is to remove particulate matter, sediment and debris. This step removes substances that may interfere with the disinfection process. Particulates will also foul filters, increase the frequency of cleaning, reduce filtration flow rate, shorten the life span of the filter and are harmful to drink.

Removal of particulates can be accomplished by filtering the water through a coffee filter or cloth and into a container for disinfection with chlorine or other disinfection chemical. One of the recommended kits used by the Marine Corps is Chlor-Floc. It is an emergency disinfectant mixed with a setting aid that helps remove particles. Next, 8 mg chlorine tablets per liter are added into a treatment container. (NSN-6850-01-374-9921)

The procedure adds 1 qt of the cleaner water into a treatment bag or a clean container. Then add the correct amount of chlorine tablets or chlorine to the container. 30 minutes of contact time is required for disinfection.

The next recommended step is filtering the water through a micro-porous ceramic filter. Using a micro-porous ceramic filter is a long established technology for effectively reducing bacteria and protozoan cysts, but not viruses. The ceramics are cleanable which enables the flow to be restored after fouling. However, the filtration efficiency varies between brands. Some contain carbon for chlorine removal, which is important when chlorine disinfection is used first.

The new CWR Ultragrav Filter, is used worldwide and has acceptable filtration efficiency of 0.9 microns and has been comparison tested against the Doulton to have a higher filtration efficiency. In addition, the newer CWR Ultragrav Ceramic has media that can remove fluoride and several heavy metals. Filtering the chlorinated water through a ceramic filter will remove any residual chlorine, parasites and bacteria that have not been killed by the chlorine, and any smaller particulates that made it through the Chlor-Floc.

As a final step, to be 100% certain all viruses are killed, exposure to ultraviolet light using the SteriPen will assure maximum safe water. Instead of UV, boiling the water for 3 minutes is also acceptable if larger quantities of water are required.

NAVMED P-510-10 Field Water Standards

General Ch- 2

• Field Water Sources
• Treatment
• Storage
• Distribution system

1. H20 for drinking must be readily available in adequate quantities to prevent dehydration. It must be potable and free of pathogens, microbiologicals and chemical contaminants.

2. Pg-13 (2-2). Purify water as close to the user as possible.

 Two sets of MFWS (Military Field Water Standards)

1. Short-term potability (STP) for up to 30 days.

• a. Disinfected of available free chlorine residual after 30 mins control time

2. Long Term Potability (LTP) for longer than 30 days.

• a. More stringent LTP MFWs based upon (EPA) and National Drinking Water Regulations (NPDWR/ NSDWR)
• b. *The residual is the same for LTP and STP Standards

3. Bottled water standard STP and LTP applied to construction produced field drinking water.

4. Non-potable water for showers and personal hygiene minimalized ____ residual of _____ on 1 ppm chlorine after 30 minutes of contact time.

• a. All non potable water must be labeled “DO NOT DRINK”

 Multiple Barrier Approach to Provide Safe Drinking Water

The approach uses 5 barriers to water contaminants that could cause adverse health effects.

• 1. Source water selection & protection
• 2. Water Treatment
• 3. Disinfection
• 4. Proper operating __________ distribution system
• 5. Operational water quality monitoring

The Military relies on proper treatment and disinfection barriers to make up for potential weaknesses in the barriers.

Field water Sources:

1. Raw water that must be treated and disinfected prior to use

• a. Above and below ground natural bodies of water
• b. Rainwater: surface, river, streams, ponds, lakes, ice, snow wells, springs may contain pathogenic microorganisms and radioactive substances. From urban and agricultural run off, industrial waste discharge, septic tanks, ground water wells and springs:
• i. Disinfect 2 Mg/L FAC: contact time 30 minutes

2. Water that has already been treated

• a. Municipal water, commercial bottled water.
• i. May contain contaminants that cause acute adverse health effects and long term health effects.

3. Bottled Water: Packaged Field Water

Pathogenic microorganisms in raw untreated surface water: parasites (cryptosporidium & giardia), bacteria, and viruses.

• Filter to 100% then disinfection to remove pathogenic microorganisms not removed by filtration. Also a secondary purpose for disinfectant residual is long term storage
• FAC (free available chlorine) 08 to 70%- 30 minutes

Disinfectants: chlorine

• Sodium Hypochlorite ( Bleach)
• Chlorine Dioxide
• Bromine
• Ultraviolet Radiation

▪ Fragile, without residual to prevent microorganisms’ regrowth.

No other disinfectant other than chlorine is acceptable that destroys microbes in water and leaves an easily detectable residue.

 Effective chlorine disinfection depends on: