Water storage and purification
My church is doing an "Emergency Preparedness Fair" this Saturday. They asked the scouts to set up a booth and talk about water storage and purification. I made a flier to pass out that has info on these two topics. I was just wondering if I missed anything. I mostly want this to be simple, fit on a page, and make people want to do further research on their own for more specifics. Grammar checks are also welcome.
Here is what I have so far:
Water Purification
Contaminant--- Effective Purification Method
Bacteria--- RO, distillation, UV, 0.3 micron pore size, boiling, chlorine dioxide, iodine, chlorine
Virus --- RO, distillation, UV, .02 micron pore size, boiling, chlorine dioxide, iodine, chlorine
Protozoa--- RO, distillation, UV, 1 micron pore size, boiling, chlorine dioxide
Chemicals-- RO, distillation, carbon absorption
Salt--- RO, distillation
Methods of purification
Reverse Osmosis (RO) - Water is forced through a semi-permeable membrane. The pore size is approximately 0.0001 microns. This method eliminates almost anything in the water. This requires a lot of pressure. All versions are very expensive.
Distillation- Water is generally vaporized, and the vapor is collected and condensed back into water. For the most part, distilling eliminates anything in the water. It can't eliminate something with the same vapor pressure, but this is rare. Special equipment is needed, but the cost is not as much as RO, and a make shift setup is easy to make.
Chemical treatments -iodine, bleach, chlorine dioxide, sodium dichloroisocyanurate etc. Chemical treatments are only effective against the living organism contaminants. It is not effective against other harmful chemicals, or salt water. Iodine should not be used by pregnant women, children, people with thyroid problems, or people with iodine allergies. Iodine should not be used for extended periods. Iodine is shown to be NOT effective against cryptosporidium. Chlorine bleach is also shown to be NOT effective against cryptosporidium. Chlorine Dioxide is effective against all living organism. Sodium dichloroisocyanurate is better for large batches (gallons) of treatment at one time.
Boiling- Boiling is effective against all living organism. The water only needs to reach a rolling boil to be considered sterile. Boiling does not remove chemicals, or make the chemicals ineffective. It also does not remove salt.
Ultraviolet Light (UV)- UV light is used to kill all organisms. It is effective against living organisms, as long as the water has a high clarity. Debris in the water will block the light and degrade effectiveness.
Carbon Absorption- Activated carbon is used to absorb chemicals in the flow stream. Carbon has a limited capacity to store these chemicals, and is only effective against certain chemicals. It does not remove living organisms. It also does not remove salt.
Filtering- Filtering passes water through something that has a specific size of opening. The pore size can vary depending on what type of filter is used. Since viruses, bacteria and protozoa are all different sizes, the size of the pores will determine which organism it is effective against. Filters are not effective against chemicals, or salt. Most backcountry water in the US only presents a threat of protozoa and bacteria.
Recommended filter buying advice-
-Look for filters with a known history. Search the internet for reviews of the filter. This generally reveals problems or concerns you might not have thought about.
-Look for filters that can be unclogged without having to buy a new filter element. The last thing you want is to be out in the middle of nowhere with a clogged filter.
-Compare filter cartridge replacement costs. This includes how often the cartridge needs to be changed
-Look at pore size. The smaller the pore size, the better, but it also flows slower. If it doesn't tell you the pore size, look elsewhere.
-Currently, my recommended filter is the Sawyer Point One. Walmart sells it for $29. Filters sold by MSR and Katadyn are also great. For home use, look at Berkey filters. Sawyer also sells a filter with a .02 pore size that can filter out viruses. As far as I know, it is the only filter on the market that can filter viruses.
Water Storage
Why store water?
Water is one of the most important things we need to survive, apart from air and shelter. Water is more important than food. You don't need a major disaster to need water storage. It can be as simple as the local supply is contaminated or water line broken.
How much do you need?
Studies have shown that 2 gallons per day per person is about minimum for cooking and consumption. This excludes personal hygiene.
Best way to store water
Water doesn't "go bad" over time. It is always water. However, if stored improperly, organisms can grow in the water, making it unsafe to drink. The best way to combat this is to store water in a cool, dark place that inhibits growth. Rotation is also good. You can also pre-treat the water with chemicals. A post water purification treatment will also work.
Containers
Plastic containers- Make sure container is food grade. Do not use containers that stored chemicals or other products. The plastic can absorb the chemicals, and then leach them into the water.
Glass containers- Makes the best container without any chance of chemical leaching. Also cheap. However, heavy, and prone to breakage.
Stainless Steel containers- Not good for storage with chlorine.
Container size
Large containers are more space efficient. They are also more cost efficient when comparing $/gallon. However, they are more of an initial purchase. Also, the larger the container, the harder it is to rotate and carry.
Small containers are easier to carry and rotate. They are also a smaller initial purchase. You can use 2 liter soda bottles as well. You can also stash them in small spaces.
