Water Purification and PET Water Bottles

     Today I am going to go into the different ways to purify water.  Whether SHTF or there is just a water main break in your area its a good thing to know how to do.  Also in the Water Basics post, the actual feasibility and safety of water bottles for water storage got brought up.  So I have gone more into depth on that topic as well.



     The first and most obvious way to purify water is by boiling it.  This is perhaps the easiest way purify your water.  When you use this method you don't want to just get the water hot, but actually at a roiling boil.  This means that there is a steady stream of large bubbles coming up from the bottom of the pot.  You want to let it boil at this level for at least one minute, though I would suggest doing it even longer than that.

     If your using this method and your water is cloudy, you might want to filter the water first by using cheese cloth, coffee filters or even cotton in a funnel before you boil the water.  Once you water has cooled down you can drink it.  If you find the water has a funny taste after boiling, that is most likely because boiling the water has deoxygenated it.  To reintroduce oxygen into the water simply take some of the water out and pour it back into the rest of the water a couple of times.  This should put oxygen back into the water and make it taste better.

     The second way to purify your water is also pretty easy.  Purification tablets.  Purification tablets purify water by using chemicals, and the most common in these tablets are iodine, chlorine, or potassium permanganate.  When using this method you want to let your purification agent work for about twenty minutes before you actually drink the water.  The downside to purification tablets?  The taste.  The water may be safe to drink but it isn't always the best tasting.

     Our next way to purify water is by using a plastic bottle, such as a water bottle.  Now in the last post on water I talked about storing water by using water bottles, and got a response back that PET water bottles wouldn't be an option.  I still maintain that they are and I go into it in further detail further down the page.  However this way of water purification does exactly that: reuses a water bottle for water purification.

     Like boiling, it is very easy to do.  You put the water in the water bottle, and lay it out in the sun for about six hours.  The ultraviolet light kills the bacteria in the water.

     You can use plastic water bottles to purify water because of a specific property of the plastic which allows ultraviolet light to pass through the plastic.  You can't purify water in a glass bottle because while you can see through glass and visible light can pass through it, when you go up to ultraviolet light levels, glass is actually opaque and the ultraviolet light can't get through.

     The fourth way to purify water is by using filtration.  You can by water filter pumps, or water bottles with filters built in.  You can even make your own DIY filtration in the wild should you need it, using various layers of materials.  With most commercial filtration devices your water should be fine to drink as is once it has gone through the filter.  If your going to be using gravel, sand and charcoal in the wild to make your own filter I would still suggest boiling the water just in case.  Just because the water looks clean doesn't mean it is.

     Another way to purify your water is by making a water still.  The idea behind a water still is that you evaporate water, which then condenses on something else such as a piece of plastic or a container.  When the water evaporates it is going to leave behind all the particles that were in the water, including bacteria.  This way when it condenses later you have pure clean water.  The water itself can even come from a number of sources.  You can use dirty water, plant materials, or even urine, and get pure water out of any of these things. Below is an example of a water still.

www.survivenature.com

     The final way you can purify water is by using bleach.  This method is very similar to how purification tablets purify water, because just like with some purification tablets, you are using chlorine.  For this you can use a basic household bleach, though you want to use ones that don't have any perfumes or other additives.  Again, just as with boiling, if there are particles in the water you may want to filter the water first.

     How much bleach you use depends on how much water you have.  To every one liter or quart of water you want to add 3 drops of bleach.  For a half gallon, 2 quarts or 2 liters you want to add 5 drops of bleach.  For one gallon it is an eight of a teaspoon, for five gallons its a half teaspoon, and for ten gallons is is a full teaspoon.  If you have more water than that, those numbers should give you enough of an idea of how much bleach you will need to use.

     You want to mix the water and bleach well and then let it sit for at least a half hour to an hour.  So it takes a little longer than purification tablets but it does basically the same thing.

     On to water bottles.  So last week I talked about water and one of the things that I talked about was water bottles and how they can be a great way to store water.  Over at Reddit, Phaederus brought up PET bottles, saying that they aren't a good option for water storage because they are designated for one time use.  He has a point.  He added a couple of links as well which I share with you as well:
-http://en.wikipedia.org/wiki/Reuse_of_water_bottles
-http://environment.about.com/od/healthenvironment/a/plastic_bottles.htm

     What is a PET bottle?  PET stands for polyethylene terephthalate and is one of the most common consumer plastics in use today.  The easiest way to check to see if something is a PET plastic is to simply check the recycle code on the bottom of the bottle.  If there is a recycle symbol with a number one in it, that means you water bottle is a PET water bottle.


      Now there are two main concerns when reusing water bottles.  The first bacteria.  The build up of bacteria can be mitigated by washing your water bottle with soap and warm water.  The second concern, which is what Phaederus was pointing out, is the possibilities of chemicals leaking out of the plastic into the water.


     All plastics leak a small amount of plasticizer over time.  However the FDA has tested these with PET plastics and determined these chemicals are harmless in small doses, because the body will be able to easily remove them.


     If you are still concerned about chemicals leaking from plastic into your water then you should just not reuse the water bottle.  The main reason chemicals may leach out of a water bottle is from wear and tear on the plastic water bottles.  Small cracks and scratches in the plastic make it weaker and more likely to leach chemicals from the plastic.  However storing water in unopened and unused water bottles shouldn't present much of a threat.


     Even so, like I said in the previous post on water basics, if you are storing water that way and are concerned about chemicals leaching into the water, simply rotate your water supply.  If you keep replacing the water bottles with new ones over time, the water shouldn't sit long enough for there to be too much leakage.


     One plastic you do want to watch out for are plastics that contain BPA.  BPA has been linked to cancer as well as causing problems with children's developing systems.  The same with PET plastics though, it is fairly easily to recognize because of the recycling number on the plastic container, which for plastics with BPA will be a number seven.


     So overall for water storage there doesn't seem to be much danger of chemicals leaching into your water from new water bottles.  There is a little bit of a higher risk if your reusing your water bottles, but still your main risk with those will be a build up of bacteria.  In fact it is the possibility of bacteria build up which often causes plastic water bottles to be classified for one time use, not the possibility of chemicals being leached into the water.  So as long as your not reusing your water bottles too many times, they should be fine and will still work well for water storage.


     Thanks to Phaederus for the comment, because it definatly brought up an important topic.  I look forward from hearing more from you and everyone else.  Also what does everyone else think on plastic water bottles for storage?  Would you use them?  Vote on it on the poll on the main blog page!  As always looking forward to your comments and questions everyone!
~Sara


Sources:
Water Purification
-http://dsc.discovery.com/adventure/top-ways-to-purify-water-in-the-wilderness.html
-http://www.doh.wa.gov/phepr/handbook/purify.htm


PET Water Bottles
-http://www.plasticsinfo.org/Functional-Nav/FAQs/Beverage-Bottles
-http://wiki.answers.com/Q/Is_it_safe_to_refill_single-use_water_bottles
-http://en.wikipedia.org/wiki/Reuse_of_water_bottles