Thursday, September 20, 2012

Water (D.K. Richardson guest post)

(The following is the next installment in D.K. Richardson's guest posts on disaster preparedness)

Chapter One
"Without the taste of water, cool water. Old Dan and I with throats burned dry. And souls that cry for water. Cool, clear, water."  -Sons of the Pioneers.
         A person can live without water for about three days, after that, you face a slow and painful death. Not just any water will do, it must be clean, free of pathogenic organisms to be of use to us humans. As I noted above, bad water has killed more people than all the wars on modern times.
How much water do you need each day?
         You need at least two liters of clean water per person per day, minimum, just to survive. If you are traveling or working, plan on at least gallon per person, per day. For hot or hot and humid weather, plan on at least five gallons a day.
Gathering water -
Where do I find water? What are good sources for water? Is some water too dangerous to use?
         I'll cover this in two parts - urban water sources and water sources you might find in areas away from the city. 
What is urban water?
         Urban surface water is generally not safe to drink without serious treatment. By this, I mean streams flowing through developed areas, lakes, ponds or other water catchment, fountain basins for example, that may be found in or near urban areas. These sources of water may contain a wild variety of contaminants - ranging from animal fecal matter and human sewage to heavy metals, petroleum products or pesticides. For this reason, most 'public' sources of surface water are not suitable for consumption. 
Are there any urban surface water sources that I could use?
         Some surface water may be used, but only with treatment. Privately owned swimming pools, that you know have been well maintained and have no external sources, such as runoff from adjoining land, may be safe to drink after minimal treatment.
         Rainwater collected from rooftops may not be suitable for use owing to contamination from the roofing materials, debris or other contaminates present on the rooftop, however, rainwater collected with known clean collectors, then stored in clean containers is an excellent source of drinking water.
Water collected from hot water tanks, the toilet tank or other internal building water storage areas may be safe to drink with minimal treatment.
         Please note that unless you are certain the water is from a potable source, do not consume the water without treatment.
Outside of developed or urban areas, surface water is still likely contaminated, but these contaminates are within your ability to treat with the simple resources available to you in a disaster. Animal or human waste is still a concern, as are pesticides, but are usually in low enough concentrations to allow treatment.
         Running springs where you can find the source, and steams fed by springs are two good sources of water. Many springs on public land have been tested; these are normally posted by the agency or person who performed the test.
         Clear, free running streams generally make a good water source, as do small ponds fed by running streams. Again, unless you know the source to be tested and deemed potable, treat the water before you consume it!
         Any well water, urban or rural, should be treated unless you know of recent testing showing the water to be potable.
Brackish water, salt water and water with high levels of alkaline as is often found in the Southwest U.S. requires specialized water treatment systems to render the water safe to consume. These reverse osmosis systems are beyond the scope of this series of blog posts. See the book for additional information under "filters".
         In the "Tales of the Chërnyi" book, the character Steven Stone gathers water by putting his empty water bottles under the edge of his shelter, so the rain runoff is captured and is ready to drink. You can do the same.

Okay, I've found a source and gathered the water. How do I store the water? What makes a good storage container? 
         Storage of treated and untreated water must be separate, it does you no good to put treated water into a container that held untreated water, so marking your containers is strongly suggested - P for potable and a D for dirty, for example. Another possibility is clear and colored soda bottles. Use clear bottles for potable, colored for water that has not been treated. You get the idea, make it simple for yourself.
         A good container has a wide mouth, a good, leak-proof cap and is of a size easy to handle depending on your location. By this I mean a one quart container is easier to carry in your backpack, where a five gallon bucket or purpose built container is a good choice for a fixed location where you or your family may decide to camp. 
How can I treat water to make it safe to drink?
        Water treatment and purification can use one of several methods. These treatments are broadly defined as:
Chemical - chlorine dioxide, unscented bleach (sodium hypochlorite), iodine, calcium hypochlorite and while there are other chemicals, they are normally limited to professional applications.
Heat - Pasteurization of water using heat to boil the water is a simple and well known process.
        Filtering in conjunction with chemical use or purifying with an advanced filter system offers a good choice as well.
Before I go further, I have a couple of important notes.
Iodine - The Department of Soil, Water, and Environmental Science, University of Arizona, tested iodine treatment for efficacy in water contaminated with Cryptosporidium oocysts. They found that just 10% were inactivated after a 20-minute exposure to iodine according to manufacturer's instructions; even after 240 minutes of exposure to iodine only 66-81% oocysts were inactivated.         
        These data strongly suggest that iodine disinfection is not effective in inactivating Cryptosporidium oocysts in water. Because this organism is common in all surface waters, it is recommended that another method of treatment be used before ingestion
        Iodine is effective against viruses common to surface water.
Commercial bleach - Bleach (sodium hypochlorite) 5+% or 6%, like you buy in the grocery store, degrades fairly quickly into salty water. Use only new or nearly new bleach to treat water! DO NOT store water in bleach bottles.
How do I use chlorine dioxide tablets?
Always follow package directions!
        These tablets are a shelf-life item. Check expirations dates twice yearly and follow vendor recommendations for time of treatment - usually a minimum of four (4) hours before consumption. Usually the product is used as one tablet per liter of water, more if water is very cold or cloudy (turbid). One brand of this product - Chlor-floc - contains a floccant to remove silt and other debris in turbid water.
        It's worth repeating - Following label directions is vial for correct treatment.
How do I safely use unscented bleach (sodium hypochlorite)?
        For products with 4% to 6% of chlorine by volume, you may treat water by putting the water in a clean container and adding 8 drops (1/8 teaspoon) of bleach for every gallon of water.
        Stir as you add the bleach and then let the water stand for at least 30 minutes. If after 30 minutes, the water does not have a residual smell of bleach, repeat the dosage of 8 drops per gallon and let it sit for another 15 minutes. If no smell is present, discard the water.
        For smaller containers - use 4 drops per 2 liter soda bottle or 2 drops for a 1 liter bottle - if water is clear.
How do I use my iodine tablets?
        First, was the container holding the tablets sealed and within the expiration date? If not, discard the tablets.
        If the bottle is open and was opened more than three months ago, discard the tablets.
        If the bottle is sealed and within the expiration period, follow label directions. As noted above iodine is not completely effective on certain protozoa. Iodine used in conjunction with an appropriate filter can render the water safe to drink. See the filter section for a discussion of filter pore size.
(Iodine is no longer sold in the EU for water treatment, pure iodine crystals have been banned in the U.S.)
What is calcium hypochlorite? 
        Calcium hypochlorite is a dry chemical sold for pool water treatment. I can be found in most 'big box stores' and stores that sell poll supplies. Read the Material Safety Data Sheet (MSDS) BEFORE you purchase or store this dry chemical. Calcium hypochlorite is a strong oxidizer, it will cause corrosion of metal. It is an "energetic reactor" which is to say, mixing with any number of materials will cause a reaction, usually violent. It will "burn' if the storage container is set alight.   
        While the material is, by its very nature quite dangerous, if does offer some benefits. First - a longer shelf life than other common water treatment chemicals. Second - density. For the same storage space, it will treat more water per volume than other choices. Last, for what it does, the price is reasonable.
How do I use calcium hypochlorite to make waster safe to drink?
        The US EPA suggests - Add and dissolve one heaping teaspoon of high-test granular calcium hypochlorite (approximately ¼ ounce) for each two gallons of water, or 5 milliliters (approximately 7 grams) per 7.5 liters of water. The mixture will produce a stock chlorine solution of approximately 500 milligrams per liter, since the calcium hypochlorite has available chlorine equal to 70 percent of its weight.
        To disinfect water, add the chlorine solution in the ratio of one part of chlorine solution to each 100 parts of water to be treated. This is roughly equal to adding 1 pint (16 ounces) of stock chlorine to each 12.5 gallons of water or (approximately ½ liter to 50 liters of water) to be disinfected. To remove any objectionable chlorine odor, aerate the disinfected water by pouring it back and forth from one clean container to another.
        If you choose to store and use this chemical, please obtain accurate measurement devices.
Okay, I'll just boil my water, how long do I need to boil it?
        Bringing water to a boil (large bubbles roiling from bottom of container) and holding that boil for at least one minute, then allowing the water to cool is one method to ensure the water is safe to drink. Boiling kills both protozoa, like Giardia lamblia and cryptosporidium (Phylum Apicomplexa) as well as viruses that pose a heath risk. Boiling DOES NOT remove other contaminates, such as pesticides, hydrocarbons or antifreeze. Ensure your source is free of these types of contaminates before treatment.
I want to buy a filter, which one is the best? How can I tell what product is a filter and what device is a purifier?
        There are many filters on the market. Generally, the price varies on how fine the product will filter water, this is called pore size - the smaller the pore size, the more expensive the product.
         First, let's look at the difference between a backpacking water filter and a backpacking water purifier. Then ask why you might opt for buying one over another?
         Put it in the simplest terms, a water filter removes protozoa and parasites, even some bacteria, but it does not remove viruses. This ability to filter is, again, a function of the filter pore size - that "micron" thing you see in the ads. These will work well with iodine to provide safe water.
         A water purifier eliminates all of these contaminates, plus viruses. In fact, the Environmental Protection Agency has set standards that require water purifiers to eliminate a percentage of all viruses. IF the device is a purifier, it will normally be registered with the EPA.
         Chemical contaminants are another story and there is no sure way to remove them, carbon block filters do a good job of removing chemicals from the water, but cleaning up the horror of urban water is not gong to be done by a simple, handheld 'filter'
BTW - about that whole 'log' thing you see in some advertisements -
        There are two different EPA classification standards for water treatment devices.
        The first classification is for a water filter, meeting this standard requires a water treatment device to demonstrate removal of at least 99.99% of pathogenic bacteria. This is known in the water filter industry as a log 4 reduction. The most common pathogenic organism cited in filtering ads?
- E-Coli
- Giardia
- Cryptosporidium
        The second classification is a water purifier, to meet this standard a water treatment device must remove at least 99.9999% of pathogenic bacteria (log 6 reduction). In addition the water purifier must be capable of reducing viruses by at least 99.999% (log 5 reduction). Given that viruses are generally measured in microns, that's quite a feat..
         We are talking very small here - viruses (0.01 microns); bacteria (0.1 micron) and protozoa (1 micron). Most purifiers use an internal carbon block filter with iodine embedded in some kind of matrix. Others actually have pore sizes on the 0.1 to 0.02 micron range. Expect to pay more for these higher quality products.
I hear I can use the sun to purify my water - is that true?"
        Yes, you can use the sun. Called SODIS for Solar water Disinfection. Place clear PET bottles holding your water out in the full sun for at least 6 hours. The solar UV radiation and heat will kill pathogenic agents in the water. This is best done in the Southern U.S., where the sun's UV rays are not as attenuated by the atmosphere. 
What about the UV light pens - are they any good?
        There are several products that generate UV light to purify clear water. I don't recommend them solely because of the need for batteries.
How do I best transport my water?
        Water weighs eight pounds per gallon. Any clean contain may be used, but give consideration to weight and ease of handling. I recommend the common one or two liter soda bottle as both very inexpensive and there are carriers made to transport the bottles that may be obtained for the asking.          Old style military canteens, sport drink bottles, iced tea bottles are all examples of good storage containers. Gallon, two and a half or five gallon water containers found in the grocery store make poor containers as they quickly become brittle and may leak at the seams. Purpose built containers, like the WaterCube boxed water or the Reliance brand Cube containers are good examples of the many products on the market today.
        Home made filters are discussed in the book.
(Thank you, Mr. Richardson.  This is excellent information!  We appreciate having you share this with us.  Readers, be sure to look for more information, as well as good prepper fiction, in books by D.K. Richardson.  Please share your comments with us!)

1 comment:

  1. Just finished your book, now looking around your blog. I love this post, it's easy to read, understand, and put into practice. Thanks for the great information per your guests post.