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You can live for a while without food but only three days without water. Less if the water is carrying infectious pathogens (like H5N1).
Everybody knows about Montzuema's revenge. That is, of course, what one often gets when drinking the water in foreign countries. If you can get that when drinking (allegedly) purified water, just imagine what could happen in a PBF scenario. Should you catch a water borne pathogen and BF you will surely die.
After your 2 (?) weeks of stored water runs out you will be needing an alternative souce of water. Getting raw water is generally not too hard. Having safe water is another story.
This is a section from my (free and I am not selling anything) Water Report:
PURIFYING WATER
You can take sewage and turn it into pure, clean drinking water. It is only a matter of the degree of purification. For the sake of this paper we mostly assume the alternative water source water quality is a bit better than sewage.
When we talk about purifying water, there are two main factors involved in water purification: improving the organoleptic characteristics (color, turbidity, taste, odor) and removing or eliminating harmful contaminants. There is a plethora of ways to do both and there are over 500 companies making products that do just that. This paper will not try to cover them all but will highlight the more common ones, especially when they are applicable to the intent of this paper.
While some technologies will do both, to try to simplify a very complex subject, I have categorized the methodologies into two main categories: disinfecting the water and filtering the water.
When looking at many commercial products you will note many claims and various marketing BS. How do you decide? There are basically two organizations that provide independent certification for water purification devices, NSF International and the Water Quality Association (WQA).
NSF International is a group that certifies various water treatment systems, distillers, and bottled water. NSF certification means that the products perform as specified and that the manufacturer?s advertisements are accurate and truthful. NSF tests certify products on an ongoing basis to make certain that product performs as advertised.
The WQA has developed a Gold Seal given to systems that have met or exceeded industry standards for contaminant reduction performance, structural integrity, and materials safety. Similar to the ?Good House Keeping Seal of Approval? the Gold Seal can help consumers choose quality water treatment products.
You need to be aware that there are a number of different NSF standards and different levels of compliance within the standards. An NSF certification by itself does not mean much and can be misleading unless you know exactly what a specific certification standard is all about. As an example, a water filter certified to meet NSF Standard 42 Class II for taste, odor and chlorine and Class II for particulate matter is not equivalent to a filter certified to meet NSF Standard 42 Class I for taste, odor and chlorine and Class I for particulate matter and Standard No. 53 for Health Effects. The second filter will remove a far wider range of contaminants and will cost considerably more, 5-10 times more, than the first one.
There are currently six NSF Drinking Water Standards relating to water filtration and treatment devices, each one designed for a specific type of product.
STANDARD 42: Drinking Water Treatment Devices - Aesthetic Effects
STANDARD 44: Cation Exchange Water Softeners
STANDARD 53: Drinking Water Treatment Devices - Health Effects
STANDARD 55: Ultraviolet Microbiological Water Treatment Systems
STANDARD 58: Reverse Osmosis Drinking Water Treatment Systems
STANDARD 62: Drinking Water Distillation Systems
You will often see products advertised as "tested to NSF standards". The key questions are ?tested by who?? and ?what were the actual results, especially when compared to the standard?? If the product was tested by NSF and certified it will be listed on the NSF website, Drinking Water Treatment Units. Certification is very expensive and not having certification doesn?t mean a particular unit isn?t any good. Conversely, relatively poor performing products can also be certified as long as they meet the minimal requirements of the particular standard and the manufacturer?s claims.
If you want to find out what are some of the ?normal? things that could be in your water, see the NSF Contaminant Guide or the EPA?s Water Borne Diseases List. If you want to find out what is actually in the drinking water in most of the major US cities, go to What's on Tap? Grading Drinking Water in U.S. Cities
EMERGENCY DISINFECTION OF WATER
All alternate source water used for drinking, cooking, preparing beverages and brushing teeth should be disinfected. The disinfected water should only be stored in clean, covered or sealed containers. You first need to pre-filter all surface water to remove any sediment and other large material that will inter with the disinfection process. While there are a variety of low cost, commercial, ?sedimentation? filter cartridges, the coarse pre-filtering can be done by running the water through several layers of clean cheese cloth (use pre-washed cotton or synthetic fiber cloth if cheese cloth is not available) or paper coffee filters (best!) into a clean container. A cotton plug in a funnel works very well. Stay away from non-food grade paper, i.e. paper towels, and unwashed cloth unless that is all you have, as both will leach harmful chemicals into the water.
You then need to sanitize the water to kill most of the pathogens that could infect and even kill you. A common misconception is that water must be 100% sterilized. In actual fact it almost always takes more than just one bug to make you sick. In order to become infected, you need to be contaminated with around 10 protozoa or virus and 10 to 1,000,000 bacteria, depending on the species. Any less than that and a healthy body can destroy them before they multiply out of control. HoRegardless, you want to sanitize the water to contain as few pathogens as reasonably possible. This is done by one of 4 common methods: heating, ultraviolet light, chemical treatment, or filtering.
As previously mentioned, there are two main factors involved in water purification: improving the organoleptic characteristics (color, turbidity, taste, odor sensations, and content) and disinfection. You can drink yucky looking, smelling, and tasting water as long as it is disinfected and doesn?t contain harmful ingredients but you do not want to be drinking crystal clear water if contains harmful biological or chemical contaminates.
This paper will concentrate on disinfecting alternate sources of water and removing many if not most harmful contents. While the organoleptic characteristic will be improved in some of the disinfecting processes, sometimes incredibly so, and the ?removing? process also improves the organoleptic characteristic, the processes normally used for specifically improving organoleptic characteristics will be discussed in the Typical Municipal Water Treatment System section.
Water contains a variety of impurities that can generally be classified into five major groups:
? Microorganisms.
? Particulate matter.
? Pyrogens, endotoxins, DNase and RNase.
? Dissolved non-ionized solids and gases.
? Dissolved ionized solids and gases.
The first 3 groups of contaminants, including the pathogens, are all essentially "particulate matter" in one form or another. The larger ones can be easily filtered out. Smaller microorganisms are hard to filter for large quantities of water and are generally killed by one means or another.
Since somebody else used to ensure that your drinking water was disinfected and contained no waterborne pathogens and now you have to do it, we will spend some time on exactly what kind of pathogens could be in your raw emergency water.
Waterborne Pathogens
Waterborne Pathogens fall into four categories:
Helminth
Helminths or parasitic worms, are not considered "microbes" in the strict sense since the adults are often large enough to be seen with the naked eye. They range from the barely visible round worms (0.3 mm) to huge tapeworms that can grow as long as 25 meters. Eggs and larvae, however, can be as small as 10 microns.
By no means complete, the most prevalent worms spread by the ingestion of water are certain nematodes (roundworms), including Guinea worm (Dracunculus medinensis), blood flukes (Schistosoma spp.), sheep liver flukes (Fasciola hepatica), stomach worm (Ascaris lumbricoides), whip worm (Trichuris trichiura), hookworm (Ancylostoma duodenale and Necator americanus) and threadworm (Strongyloides stercoralis). Schistosomes are a growing problem around the world. Nematodes can also ingest bacteria and protect them from disinfection. Go here to see the full list and here and here for more info. NOTE: you might want to eat first before you start clicking on the links otherwise you may not have an appetite after.
Common disinfection methods kill Helminths. Filtration to one micron removes all helminths, including their eggs and larvae.
Protozoa
Protozoa are single-celled eukaryotes (organisms whose cells have nuclei) that show some characteristics usually associated with animals, most notably mobility and heterotrophy that vary in size from 2 to 100 microns. They live in many insects and animals and many form cysts (protective shells) in their life cycles to survive adverse conditions or their host organism. Protozoa cysts are the largest pathogens in drinking water, and are responsible for many of the waterborne disease cases in the US. Protozoa cysts range in size from 2 to 15 microns but can squeeze through smaller openings, especially under higher water pressures.
Protozoa include Giardia lamblia (Giardia) and Cryptosporidium Parvum (Crypto), two of the most ubiquitous parasites in the world. Cyclospora cayetanensis, is an increasingly common waterborne pathogen. Then there is Naegleria fowleri and Acanthamoeba spp, Entamoeba histolytica, and Isospora belli.
According to Chuck Hilber, professor emeritus at Colorado State University, and a parasitologist who has spent a lifetime analyzing backcountry water "In one of our studies we had over 10,000 samples from streams all across America, Alaska to Arizona, and we didn't find one without giardia". Other tests have also found Giardia and/or Crypto in up to 5% of vertical wells and 26% of springs in the US.
While protozoa are fairly easily killed with various chemical disinfectants, protozoa egg cysts, most notably cryptosporidium, are VERY resistant to almost all chemical disinfectants and must therefore be removed mechanically by filtration. While a 2 micron absolute filter will probably work against most or even all cysts, in order to be absolutely sure, many experts recommend an absolute pore size of 1 micron.
Bacteria
Bacteria can generally be defined as a class of microscopic, single-cell procaryotes that reproduce by binary fission. Bacteria are the most prevalent organism on earth. A cubic centimeter of soil contains more than a million organisms. Bacteria are smaller than protozoa and are responsible for many diseases such as typhoid fever, cholera, diarrhea, and dysentery. Bacteria range in size from 0.2 to 0.6 microns.
The most medically important waterborne diseases caused by bacteria include typhoid (Salmonella typhi), paratyphoid (Salmonella paratyphi-A), bacillary dysentery (Shigella spp.), campylobacter enteritis (Campylobacter jejuni) salmonellosis and enteric fever (Salmonella spp.), leptospirosis (Leptospira), Campylobacter, cholera (Vibrio cholerae), Aeromonas hydrophila, and the very nasty Escherichia Coli serotype O157:H7, a rare variety of the common E.coli bacteria.
Because bacteria are essential to the processing of nutrients, they are present in astounding numbers in the digestive system of mammals. Once deposited in surface water, they can survive for weeks, awaiting further ingestion by a carrier who can support their reproduction.
Waterborne bacteria can be easily killed with a variety of disinfection methods but a 0.2 micron absolute filter is required to filter them out of water.
Virus
Are the smallest agents of disease, and are now considered to be the 2nd most problematic pathogen, behind protozoa. Waterborne pathogenic viruses range in size from 0.004 - 0.030 microns (4 - 30 nanometers), and are too small to be filtered out by a mechanical filter.. By one calculation, a single gram of typical human feces contained one billion viruses.
As with protozoa, most waterborne viral diseases don't present a lethal hazard to a healthy adult, however there are some that do. All waterborne enteric viruses affecting humans occur solely in humans, thus animal waste doesn't present much of a viral threat as in the other three categories. Historically, few cases of waterborne disease have been attributed to viruses but this probably had more to do with the limitations in diagnosis.
However, according to Timothy Ford of the Harvard School of Public Health, advances in identifying viral agents has significantly increased the number of cases of enteric disease that are determined to be of viral etiology. A number of authors now suggest that Norwalk virus and Norwalk-like viruses are the major causes of both food and waterborne illnesses worldwide, including 6.5 million annual cases of waterborne viral disease in the United States alone.
Echovirus and poliovirus are also transmitted by drinking water as are Hepatitis A, C, E, rotaviruses and enteroviruses which have also shown some resistance to normal levels of chlorination. Since there is limited treatment for viral infections, waterborne viruses are particularly dangerous, especially among immuno-compromised populations. In developing countries, hepatitis A and E are extremely dangerous, with hepatitis E causing 1 to 2 percent mortality in the general population, and a horrific 20 to 30 percent mortality in pregnant women.
Waterborne viruses are normally controlled through disinfection as they are very difficult to filter except through using a Reverse Osmosis filter with membrane pores smaller than .0.002 micron ( 2 nanometer).
The last 3 are dissolved non-ionized solids and gasses include natural organic remains, man-made organic chemicals. These are a bit harder to remove, regardless of quantity.
Dissolved ionized solids and gasses come from exposure to rock and minerals in the earth. These are such things as sodium chloride, calcium carbonate (limestone), calcium magnesium carbonate (dolomite), and other soluble chemicals that occur either naturally or as a result of man-kind's contamination of the water supply. The main ionized gas is carbon dioxide. These contaminants contribute to the hardness, conductivity, alkalinity and pH of the water. Many of the dissolved ionized solids and gasses will not hurt you and some, like calcium and magnesium, are actually beneficial. Others like arsenic are deadly. Regardless, some can be easily removed and others are hard to remove.
Discussion of the four main disinfection processes follows. Some of the processes will have subcategories as noted. Depending on the level of contamination in your water and how pure of water you want, you will most likely be using two or more methods.
However before we do that let us revisit the major premise of this paper:
Everything you ever wanted to know or at least need to know about water so that you won?t ever be without safe drinking water.
As a result, we will digress a bit and spend some time on one subject you need to know more about so that you can fulfill the goal of this paper because it impacts many of the things you will be doing. The subject is one of the protozoa mentioned earlier:
Cryptosporidium
Cryptosporidium, ?crypto? for short, is a widespread, water borne protozoa. If you get infected you get a disease called Cryptosporidiosis and you will get very sick but probably won?t die. If you get Cryptosporidiosis and have or catch nearly any other series disease at the same time, including ?regular? influenza you will probably die. However, if you get Cryptosporidiosis and Bird Flu, you will surely die.
In discussing Cryptosporidium, it is worth noting that there is a similar pathogen called Giardia, which is just as widespread, if not more so, and which causes Giardiasis and is another disease you do not want to be catching either. However, in the grand scheme of things, Giardia is not quite as bad as Crypto and any mediation efforts done for Crypto will automatically take care of Giardia. In fact, many of the efforts to eradicate Crypto will also take care of most pathogens, with the possible exception of a virus.
Cryptosporidium is already in the raw water of most municipal water supplies as nearly all surface water sources are polluted with Crypto and it is getting worse every year. Crypto has a life cycle where its eggs, called cysts, have a nearly impenetrable hard outer shell. In this stage it is VERY HARD to kill. As a result your municipal water source has added or increased the methods used to try to kill it and usually added additional and very extensive filtering to prevent it from getting through and coming out your tap.
Occasionally, however, something goes wrong and, as a result of Cryptosporidium, bad things can happen to a lot of people. In the Milwaukee incident, 400,000 people were infected, thousands hospitalized, and hundreds died. Many of those who were infected never completely recovered and have lasting side affects. Smaller Crypto infections are occurring with increasing frequency every year, including recent outbreaks in Nevada, Oregon and Georgia.
The reason you are even reading this paper is because you expect to be in a situation where the water coming out of your tap is suspect or there is no water coming out of your tap and most likely the alternative source of water that you will be using is polluted. If that water is surface water there is a high probability that it is already infected with Cryptosporidium. As the Milwaukee incident revealed however, it does not take an outside factor to occur for you to get infected with Cryptosporidium.
How hard are Cryptosporidium cysts to kill? As noted in Disinfection and oocyst survival ?Few commercial disinfectants are effective against the oocysts, nor is chlorination at normal drinking water treatment levels? and one study noted that ?long-term exposure to 70-100% bleach is necessary to completely eliminate infectivity? and ?3% chlorine as Na hypochlorite for up to 18 h does not affect viability.? Another report noted that ?crypto cysts suspended in 5.25% aqueous Na hypochlorite (full-strength Clorox bleach) for up to 2 h still initiated infection.?
For more information on Cryptosporidium, see:
A Review of Cryptosporidiosis and Cryptosporidium parvum: an emerging pathogen
What will disinfect water of Cryptosporidium?
According to the Army:
Chlorine: Ineffective, even at high CT values. (CT= Concentration X Time in mg minutes per liter)
Chlorine Dioxide: Effective at high CT values. If possible, use longer contact times instead of higher dosages to achieve adequate CT values. Colder water temperatures require higher CT values. Use a two-fold increase in CT for every 10? C decrease.
Iodine: Not Effective
UV: Effective at reasonable doses.
The bottom line for our emergency water scenarios is that there is nothing you can add to polluted water to be 100% sure of killing Cryptosporidium, despite what others may be saying. The only viable additive solution for our purposes that might POSSIBLY kill Cryptosporidium is Chlorine Dioxide, covered in the Chemical section, below.
However, all is not lost. Crypto can be killed with heat and is relatively easy to filter out of water. The heating methods are discussed immediately below and for filtering all you need is a mechanical filter with an absolute pore size of 2 microns, ideally 1 micron. This is covered in the Filter section.
When selecting a filtration system for Cryptosporidium, the system should have one or all of the following characteristics (Juranek, 1995):
? it can remove particles that are 0.1-1 micrometers in size
? filters water by reverse osmosis
? it has an "absolute" 1-micron filter
? meets NSF standard no. 53 for "cyst removal"
On the other hand, filters that have the following characteristics do NOT guarantee >99% removal of Cryptosporidium oocysts (Juranek, 1995):
? filters with a "nominal" 1-micron rating
? only employs ultraviolet light
? uses only activated carbon for filtration
? utilizes pentiodide-impregnated resins
? it is listed as effective against the Giardia species
*************
There are over 50 links in that section. Too many to go back in and add and I have no clue why they aren't coming over when I copy and paste from the Word source document.
If you want a copy of the (free and I am not selling anything) Water Report, about 95 pages, send me an e-mail. pfwag@lycos.com
Here is the Index:
INTRODUCTION
WATER
WHY SHOULD YOU STORE WATER
HOW MUCH WATER IS NEEDED?
SOURCES of WATER
A. WATER IN YOUR HOME
Hot Water Heater
Water Pipes
Freezer
Toilet
Swimming pool
B. STORING WATER
Bottled Water and other liquids
Plastic Bottle Types
Plastic Water Jugs
55G water barrels
Water Bladder (Pillow Tank)
Water Bed Mattresses and Other Storage Devices
Water Tanks
Swimming Pool
Using Empty Food Containers for Storing Water
Filling Water Storage Containers
Taste & Smell
Shelf Life
C. WELL WATER
D. SURFACE WATER
Springs
Rivers, Lakes, and Ponds
Rainwater
Snow or Ice
PURIFYING WATER
EMERGENCY DISINFECTION OF WATER
Waterborne Pathogens
Cryptosporidium
HEATING
Boiling
Distilling
Solar Still
ULTRAVIOLET LIGHT
PASTEURIZATION
SOLAR DISINFECTANT of WATER
CHEMICALLY TREAT
Iodine
Chlorine
Residual Chlorine ? dpd indicator test
Additional Information on Chlorine
Calcium Hypochlorite
Chlorine Dioxide
Ozone
Other Chemical Treatments
Miracle Water Treatments
FILTERING
Cartride Filters
Reverse Osmosis
Activated Carbon Filter
Granular Activated Carbon (GAC)
GAC pitcher and faucet mounted filters
Solid Block Activated Carbon (SBAC)
Speciality Filters
Filtering Conclusions
Filtering Swimming Pool Water
Portable Filters
Gravity Filters
Low Pressure Filter
MISCELLANEOUS
TYPICAL MUNICIPAL WATER TREATMENT SYSTEM
Primary Treatment
Secondary Treatment
Tertiary Treatment
Final Adjustments
INSTRUCTIONS FOR MAKING A MINI-WATER TREATMENT SYSTEM
Aeration Methods
Procedure For Coagulation (flocculation) Removal of Particulate Matter
MAKING A LARGE CAPACITY GRANULAR ACTIVATED CHARCOL FILTER
Parts to Get for the GAC and particulate filters
WHAT YOU SHOULD GET TO ALWAYS HAVE SAFE DRINKING WATER
TIPS for CONSERVING WATER
Sanitation
Other Tips
WATER LINKS & REFERENCES
WHO - Technical Notes for Emergencies
and for that last reference:
WHO - Technical Notes for Emergencies
1 - Cleaning and disinfecting wells [pdf - htm]
2 - Cleaning and disinfecting boreholes [pdf - htm]
3 - Cleaning and disinfecting water storage tanks [pdf - htm]
4 - Rehabilitating small-scale water dist. systems [pdf - htm]
5 - Emergency treatment of drinking water [pdf - htm]
6 - Rehabilitating water treatment works [pdf - htm]
7 - Solid waste management in emergencies [pdf - htm]
8 - Disposal of dead bodies [pdf - htm]
9 - Minimum water quantity [pdf - htm]
10 - Essential hygiene messages [pdf - htm]
11 - How to measure chlorine residual [pdf - htm]
12 - Delivering safe water by tanker [pdf - htm]
13 - Emergency sanitation - planning [pdf - htm]
14 - Emergency sanitation - technical options [pdf - htm]
Everybody knows about Montzuema's revenge. That is, of course, what one often gets when drinking the water in foreign countries. If you can get that when drinking (allegedly) purified water, just imagine what could happen in a PBF scenario. Should you catch a water borne pathogen and BF you will surely die.
After your 2 (?) weeks of stored water runs out you will be needing an alternative souce of water. Getting raw water is generally not too hard. Having safe water is another story.
This is a section from my (free and I am not selling anything) Water Report:
PURIFYING WATER
You can take sewage and turn it into pure, clean drinking water. It is only a matter of the degree of purification. For the sake of this paper we mostly assume the alternative water source water quality is a bit better than sewage.
When we talk about purifying water, there are two main factors involved in water purification: improving the organoleptic characteristics (color, turbidity, taste, odor) and removing or eliminating harmful contaminants. There is a plethora of ways to do both and there are over 500 companies making products that do just that. This paper will not try to cover them all but will highlight the more common ones, especially when they are applicable to the intent of this paper.
While some technologies will do both, to try to simplify a very complex subject, I have categorized the methodologies into two main categories: disinfecting the water and filtering the water.
When looking at many commercial products you will note many claims and various marketing BS. How do you decide? There are basically two organizations that provide independent certification for water purification devices, NSF International and the Water Quality Association (WQA).
NSF International is a group that certifies various water treatment systems, distillers, and bottled water. NSF certification means that the products perform as specified and that the manufacturer?s advertisements are accurate and truthful. NSF tests certify products on an ongoing basis to make certain that product performs as advertised.
The WQA has developed a Gold Seal given to systems that have met or exceeded industry standards for contaminant reduction performance, structural integrity, and materials safety. Similar to the ?Good House Keeping Seal of Approval? the Gold Seal can help consumers choose quality water treatment products.
You need to be aware that there are a number of different NSF standards and different levels of compliance within the standards. An NSF certification by itself does not mean much and can be misleading unless you know exactly what a specific certification standard is all about. As an example, a water filter certified to meet NSF Standard 42 Class II for taste, odor and chlorine and Class II for particulate matter is not equivalent to a filter certified to meet NSF Standard 42 Class I for taste, odor and chlorine and Class I for particulate matter and Standard No. 53 for Health Effects. The second filter will remove a far wider range of contaminants and will cost considerably more, 5-10 times more, than the first one.
There are currently six NSF Drinking Water Standards relating to water filtration and treatment devices, each one designed for a specific type of product.
STANDARD 42: Drinking Water Treatment Devices - Aesthetic Effects
STANDARD 44: Cation Exchange Water Softeners
STANDARD 53: Drinking Water Treatment Devices - Health Effects
STANDARD 55: Ultraviolet Microbiological Water Treatment Systems
STANDARD 58: Reverse Osmosis Drinking Water Treatment Systems
STANDARD 62: Drinking Water Distillation Systems
You will often see products advertised as "tested to NSF standards". The key questions are ?tested by who?? and ?what were the actual results, especially when compared to the standard?? If the product was tested by NSF and certified it will be listed on the NSF website, Drinking Water Treatment Units. Certification is very expensive and not having certification doesn?t mean a particular unit isn?t any good. Conversely, relatively poor performing products can also be certified as long as they meet the minimal requirements of the particular standard and the manufacturer?s claims.
If you want to find out what are some of the ?normal? things that could be in your water, see the NSF Contaminant Guide or the EPA?s Water Borne Diseases List. If you want to find out what is actually in the drinking water in most of the major US cities, go to What's on Tap? Grading Drinking Water in U.S. Cities
EMERGENCY DISINFECTION OF WATER
All alternate source water used for drinking, cooking, preparing beverages and brushing teeth should be disinfected. The disinfected water should only be stored in clean, covered or sealed containers. You first need to pre-filter all surface water to remove any sediment and other large material that will inter with the disinfection process. While there are a variety of low cost, commercial, ?sedimentation? filter cartridges, the coarse pre-filtering can be done by running the water through several layers of clean cheese cloth (use pre-washed cotton or synthetic fiber cloth if cheese cloth is not available) or paper coffee filters (best!) into a clean container. A cotton plug in a funnel works very well. Stay away from non-food grade paper, i.e. paper towels, and unwashed cloth unless that is all you have, as both will leach harmful chemicals into the water.
You then need to sanitize the water to kill most of the pathogens that could infect and even kill you. A common misconception is that water must be 100% sterilized. In actual fact it almost always takes more than just one bug to make you sick. In order to become infected, you need to be contaminated with around 10 protozoa or virus and 10 to 1,000,000 bacteria, depending on the species. Any less than that and a healthy body can destroy them before they multiply out of control. HoRegardless, you want to sanitize the water to contain as few pathogens as reasonably possible. This is done by one of 4 common methods: heating, ultraviolet light, chemical treatment, or filtering.
As previously mentioned, there are two main factors involved in water purification: improving the organoleptic characteristics (color, turbidity, taste, odor sensations, and content) and disinfection. You can drink yucky looking, smelling, and tasting water as long as it is disinfected and doesn?t contain harmful ingredients but you do not want to be drinking crystal clear water if contains harmful biological or chemical contaminates.
This paper will concentrate on disinfecting alternate sources of water and removing many if not most harmful contents. While the organoleptic characteristic will be improved in some of the disinfecting processes, sometimes incredibly so, and the ?removing? process also improves the organoleptic characteristic, the processes normally used for specifically improving organoleptic characteristics will be discussed in the Typical Municipal Water Treatment System section.
Water contains a variety of impurities that can generally be classified into five major groups:
? Microorganisms.
? Particulate matter.
? Pyrogens, endotoxins, DNase and RNase.
? Dissolved non-ionized solids and gases.
? Dissolved ionized solids and gases.
The first 3 groups of contaminants, including the pathogens, are all essentially "particulate matter" in one form or another. The larger ones can be easily filtered out. Smaller microorganisms are hard to filter for large quantities of water and are generally killed by one means or another.
Since somebody else used to ensure that your drinking water was disinfected and contained no waterborne pathogens and now you have to do it, we will spend some time on exactly what kind of pathogens could be in your raw emergency water.
Waterborne Pathogens
Waterborne Pathogens fall into four categories:
Helminth
Helminths or parasitic worms, are not considered "microbes" in the strict sense since the adults are often large enough to be seen with the naked eye. They range from the barely visible round worms (0.3 mm) to huge tapeworms that can grow as long as 25 meters. Eggs and larvae, however, can be as small as 10 microns.
By no means complete, the most prevalent worms spread by the ingestion of water are certain nematodes (roundworms), including Guinea worm (Dracunculus medinensis), blood flukes (Schistosoma spp.), sheep liver flukes (Fasciola hepatica), stomach worm (Ascaris lumbricoides), whip worm (Trichuris trichiura), hookworm (Ancylostoma duodenale and Necator americanus) and threadworm (Strongyloides stercoralis). Schistosomes are a growing problem around the world. Nematodes can also ingest bacteria and protect them from disinfection. Go here to see the full list and here and here for more info. NOTE: you might want to eat first before you start clicking on the links otherwise you may not have an appetite after.
Common disinfection methods kill Helminths. Filtration to one micron removes all helminths, including their eggs and larvae.
Protozoa
Protozoa are single-celled eukaryotes (organisms whose cells have nuclei) that show some characteristics usually associated with animals, most notably mobility and heterotrophy that vary in size from 2 to 100 microns. They live in many insects and animals and many form cysts (protective shells) in their life cycles to survive adverse conditions or their host organism. Protozoa cysts are the largest pathogens in drinking water, and are responsible for many of the waterborne disease cases in the US. Protozoa cysts range in size from 2 to 15 microns but can squeeze through smaller openings, especially under higher water pressures.
Protozoa include Giardia lamblia (Giardia) and Cryptosporidium Parvum (Crypto), two of the most ubiquitous parasites in the world. Cyclospora cayetanensis, is an increasingly common waterborne pathogen. Then there is Naegleria fowleri and Acanthamoeba spp, Entamoeba histolytica, and Isospora belli.
According to Chuck Hilber, professor emeritus at Colorado State University, and a parasitologist who has spent a lifetime analyzing backcountry water "In one of our studies we had over 10,000 samples from streams all across America, Alaska to Arizona, and we didn't find one without giardia". Other tests have also found Giardia and/or Crypto in up to 5% of vertical wells and 26% of springs in the US.
While protozoa are fairly easily killed with various chemical disinfectants, protozoa egg cysts, most notably cryptosporidium, are VERY resistant to almost all chemical disinfectants and must therefore be removed mechanically by filtration. While a 2 micron absolute filter will probably work against most or even all cysts, in order to be absolutely sure, many experts recommend an absolute pore size of 1 micron.
Bacteria
Bacteria can generally be defined as a class of microscopic, single-cell procaryotes that reproduce by binary fission. Bacteria are the most prevalent organism on earth. A cubic centimeter of soil contains more than a million organisms. Bacteria are smaller than protozoa and are responsible for many diseases such as typhoid fever, cholera, diarrhea, and dysentery. Bacteria range in size from 0.2 to 0.6 microns.
The most medically important waterborne diseases caused by bacteria include typhoid (Salmonella typhi), paratyphoid (Salmonella paratyphi-A), bacillary dysentery (Shigella spp.), campylobacter enteritis (Campylobacter jejuni) salmonellosis and enteric fever (Salmonella spp.), leptospirosis (Leptospira), Campylobacter, cholera (Vibrio cholerae), Aeromonas hydrophila, and the very nasty Escherichia Coli serotype O157:H7, a rare variety of the common E.coli bacteria.
Because bacteria are essential to the processing of nutrients, they are present in astounding numbers in the digestive system of mammals. Once deposited in surface water, they can survive for weeks, awaiting further ingestion by a carrier who can support their reproduction.
Waterborne bacteria can be easily killed with a variety of disinfection methods but a 0.2 micron absolute filter is required to filter them out of water.
Virus
Are the smallest agents of disease, and are now considered to be the 2nd most problematic pathogen, behind protozoa. Waterborne pathogenic viruses range in size from 0.004 - 0.030 microns (4 - 30 nanometers), and are too small to be filtered out by a mechanical filter.. By one calculation, a single gram of typical human feces contained one billion viruses.
As with protozoa, most waterborne viral diseases don't present a lethal hazard to a healthy adult, however there are some that do. All waterborne enteric viruses affecting humans occur solely in humans, thus animal waste doesn't present much of a viral threat as in the other three categories. Historically, few cases of waterborne disease have been attributed to viruses but this probably had more to do with the limitations in diagnosis.
However, according to Timothy Ford of the Harvard School of Public Health, advances in identifying viral agents has significantly increased the number of cases of enteric disease that are determined to be of viral etiology. A number of authors now suggest that Norwalk virus and Norwalk-like viruses are the major causes of both food and waterborne illnesses worldwide, including 6.5 million annual cases of waterborne viral disease in the United States alone.
Echovirus and poliovirus are also transmitted by drinking water as are Hepatitis A, C, E, rotaviruses and enteroviruses which have also shown some resistance to normal levels of chlorination. Since there is limited treatment for viral infections, waterborne viruses are particularly dangerous, especially among immuno-compromised populations. In developing countries, hepatitis A and E are extremely dangerous, with hepatitis E causing 1 to 2 percent mortality in the general population, and a horrific 20 to 30 percent mortality in pregnant women.
Waterborne viruses are normally controlled through disinfection as they are very difficult to filter except through using a Reverse Osmosis filter with membrane pores smaller than .0.002 micron ( 2 nanometer).
The last 3 are dissolved non-ionized solids and gasses include natural organic remains, man-made organic chemicals. These are a bit harder to remove, regardless of quantity.
Dissolved ionized solids and gasses come from exposure to rock and minerals in the earth. These are such things as sodium chloride, calcium carbonate (limestone), calcium magnesium carbonate (dolomite), and other soluble chemicals that occur either naturally or as a result of man-kind's contamination of the water supply. The main ionized gas is carbon dioxide. These contaminants contribute to the hardness, conductivity, alkalinity and pH of the water. Many of the dissolved ionized solids and gasses will not hurt you and some, like calcium and magnesium, are actually beneficial. Others like arsenic are deadly. Regardless, some can be easily removed and others are hard to remove.
Discussion of the four main disinfection processes follows. Some of the processes will have subcategories as noted. Depending on the level of contamination in your water and how pure of water you want, you will most likely be using two or more methods.
However before we do that let us revisit the major premise of this paper:
Everything you ever wanted to know or at least need to know about water so that you won?t ever be without safe drinking water.
As a result, we will digress a bit and spend some time on one subject you need to know more about so that you can fulfill the goal of this paper because it impacts many of the things you will be doing. The subject is one of the protozoa mentioned earlier:
Cryptosporidium
Cryptosporidium, ?crypto? for short, is a widespread, water borne protozoa. If you get infected you get a disease called Cryptosporidiosis and you will get very sick but probably won?t die. If you get Cryptosporidiosis and have or catch nearly any other series disease at the same time, including ?regular? influenza you will probably die. However, if you get Cryptosporidiosis and Bird Flu, you will surely die.
In discussing Cryptosporidium, it is worth noting that there is a similar pathogen called Giardia, which is just as widespread, if not more so, and which causes Giardiasis and is another disease you do not want to be catching either. However, in the grand scheme of things, Giardia is not quite as bad as Crypto and any mediation efforts done for Crypto will automatically take care of Giardia. In fact, many of the efforts to eradicate Crypto will also take care of most pathogens, with the possible exception of a virus.
Cryptosporidium is already in the raw water of most municipal water supplies as nearly all surface water sources are polluted with Crypto and it is getting worse every year. Crypto has a life cycle where its eggs, called cysts, have a nearly impenetrable hard outer shell. In this stage it is VERY HARD to kill. As a result your municipal water source has added or increased the methods used to try to kill it and usually added additional and very extensive filtering to prevent it from getting through and coming out your tap.
Occasionally, however, something goes wrong and, as a result of Cryptosporidium, bad things can happen to a lot of people. In the Milwaukee incident, 400,000 people were infected, thousands hospitalized, and hundreds died. Many of those who were infected never completely recovered and have lasting side affects. Smaller Crypto infections are occurring with increasing frequency every year, including recent outbreaks in Nevada, Oregon and Georgia.
The reason you are even reading this paper is because you expect to be in a situation where the water coming out of your tap is suspect or there is no water coming out of your tap and most likely the alternative source of water that you will be using is polluted. If that water is surface water there is a high probability that it is already infected with Cryptosporidium. As the Milwaukee incident revealed however, it does not take an outside factor to occur for you to get infected with Cryptosporidium.
How hard are Cryptosporidium cysts to kill? As noted in Disinfection and oocyst survival ?Few commercial disinfectants are effective against the oocysts, nor is chlorination at normal drinking water treatment levels? and one study noted that ?long-term exposure to 70-100% bleach is necessary to completely eliminate infectivity? and ?3% chlorine as Na hypochlorite for up to 18 h does not affect viability.? Another report noted that ?crypto cysts suspended in 5.25% aqueous Na hypochlorite (full-strength Clorox bleach) for up to 2 h still initiated infection.?
For more information on Cryptosporidium, see:
A Review of Cryptosporidiosis and Cryptosporidium parvum: an emerging pathogen
What will disinfect water of Cryptosporidium?
According to the Army:
Chlorine: Ineffective, even at high CT values. (CT= Concentration X Time in mg minutes per liter)
Chlorine Dioxide: Effective at high CT values. If possible, use longer contact times instead of higher dosages to achieve adequate CT values. Colder water temperatures require higher CT values. Use a two-fold increase in CT for every 10? C decrease.
Iodine: Not Effective
UV: Effective at reasonable doses.
The bottom line for our emergency water scenarios is that there is nothing you can add to polluted water to be 100% sure of killing Cryptosporidium, despite what others may be saying. The only viable additive solution for our purposes that might POSSIBLY kill Cryptosporidium is Chlorine Dioxide, covered in the Chemical section, below.
However, all is not lost. Crypto can be killed with heat and is relatively easy to filter out of water. The heating methods are discussed immediately below and for filtering all you need is a mechanical filter with an absolute pore size of 2 microns, ideally 1 micron. This is covered in the Filter section.
When selecting a filtration system for Cryptosporidium, the system should have one or all of the following characteristics (Juranek, 1995):
? it can remove particles that are 0.1-1 micrometers in size
? filters water by reverse osmosis
? it has an "absolute" 1-micron filter
? meets NSF standard no. 53 for "cyst removal"
On the other hand, filters that have the following characteristics do NOT guarantee >99% removal of Cryptosporidium oocysts (Juranek, 1995):
? filters with a "nominal" 1-micron rating
? only employs ultraviolet light
? uses only activated carbon for filtration
? utilizes pentiodide-impregnated resins
? it is listed as effective against the Giardia species
*************
There are over 50 links in that section. Too many to go back in and add and I have no clue why they aren't coming over when I copy and paste from the Word source document.
If you want a copy of the (free and I am not selling anything) Water Report, about 95 pages, send me an e-mail. pfwag@lycos.com
Here is the Index:
INTRODUCTION
WATER
WHY SHOULD YOU STORE WATER
HOW MUCH WATER IS NEEDED?
SOURCES of WATER
A. WATER IN YOUR HOME
Hot Water Heater
Water Pipes
Freezer
Toilet
Swimming pool
B. STORING WATER
Bottled Water and other liquids
Plastic Bottle Types
Plastic Water Jugs
55G water barrels
Water Bladder (Pillow Tank)
Water Bed Mattresses and Other Storage Devices
Water Tanks
Swimming Pool
Using Empty Food Containers for Storing Water
Filling Water Storage Containers
Taste & Smell
Shelf Life
C. WELL WATER
D. SURFACE WATER
Springs
Rivers, Lakes, and Ponds
Rainwater
Snow or Ice
PURIFYING WATER
EMERGENCY DISINFECTION OF WATER
Waterborne Pathogens
Cryptosporidium
HEATING
Boiling
Distilling
Solar Still
ULTRAVIOLET LIGHT
PASTEURIZATION
SOLAR DISINFECTANT of WATER
CHEMICALLY TREAT
Iodine
Chlorine
Residual Chlorine ? dpd indicator test
Additional Information on Chlorine
Calcium Hypochlorite
Chlorine Dioxide
Ozone
Other Chemical Treatments
Miracle Water Treatments
FILTERING
Cartride Filters
Reverse Osmosis
Activated Carbon Filter
Granular Activated Carbon (GAC)
GAC pitcher and faucet mounted filters
Solid Block Activated Carbon (SBAC)
Speciality Filters
Filtering Conclusions
Filtering Swimming Pool Water
Portable Filters
Gravity Filters
Low Pressure Filter
MISCELLANEOUS
TYPICAL MUNICIPAL WATER TREATMENT SYSTEM
Primary Treatment
Secondary Treatment
Tertiary Treatment
Final Adjustments
INSTRUCTIONS FOR MAKING A MINI-WATER TREATMENT SYSTEM
Aeration Methods
Procedure For Coagulation (flocculation) Removal of Particulate Matter
MAKING A LARGE CAPACITY GRANULAR ACTIVATED CHARCOL FILTER
Parts to Get for the GAC and particulate filters
WHAT YOU SHOULD GET TO ALWAYS HAVE SAFE DRINKING WATER
TIPS for CONSERVING WATER
Sanitation
Other Tips
WATER LINKS & REFERENCES
WHO - Technical Notes for Emergencies
and for that last reference:
WHO - Technical Notes for Emergencies
1 - Cleaning and disinfecting wells [pdf - htm]
2 - Cleaning and disinfecting boreholes [pdf - htm]
3 - Cleaning and disinfecting water storage tanks [pdf - htm]
4 - Rehabilitating small-scale water dist. systems [pdf - htm]
5 - Emergency treatment of drinking water [pdf - htm]
6 - Rehabilitating water treatment works [pdf - htm]
7 - Solid waste management in emergencies [pdf - htm]
8 - Disposal of dead bodies [pdf - htm]
9 - Minimum water quantity [pdf - htm]
10 - Essential hygiene messages [pdf - htm]
11 - How to measure chlorine residual [pdf - htm]
12 - Delivering safe water by tanker [pdf - htm]
13 - Emergency sanitation - planning [pdf - htm]
14 - Emergency sanitation - technical options [pdf - htm]
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