Chapter Meeting Review: Water Purification Techniques 4/2/2020

Water Purification

  1. Why is it important?
    1. Water purification is important because it ensures that the water you are drinking is safe. There are several different contaminants that come from contaminated water, and also several ways to purify water. These will all be discussed here.
    2. Specific Examples of Contaminants
      1. Bacteria/Viruses 
        1. Potentially hazardous species include Legionella, which causes Legionnaires Disease (a type of pneumonia), E. coli which is caused by feces in water, and Enteroviruses, which include polioviruses, echoviruses and coxsackieviruses, which all cause an assortment of diseases
      2. Parasites
        1. Potentially hazardous parasite species includes Guinea Worms, which causes an assortment of issues like nausea, diarrhea, and fevers before the worm emerges through a blister to repopulate a water source and Schistosomiasis, which is a parasitic snail that messes up your internal organs
      3. Toxins
        1. Some toxins (defined here as chemicals and metals) are purposely introduced in small amounts to kill bacteria and parasites, but can be toxic in larger doses
        2. Common toxins include chlorine, lead, hydrogen sulfide, and chloride 
      4. Other Impurities
        1. Other impurities include a large amount of ammonia, nitrites, and nitrates, which are produced by decomposing matter and bacteria, Cholera, which is a disease which is caused by drinking contaminated water and getting diarrhea, which can lead to dehydration.
  2. Identification of Water Source/Type, Red Flags, & What of the above to be concerned about with each
    1. Groundwater
      1. Groundwater is water that is held in the soil or in rock crevices. Groundwater is used by 51% of the total US population and 99% of the rural population. The best way to find groundwater is to look at the topography of the area you are in. The most common contaminants are metals and chemicals. Red Flags for groundwater are if it is by any roads or habitated areas. Groundwater usually looks clear since the ground filters out large particles, but you can’t always see chemicals and metals in the water.
    2. Lakes/Reservoirs
      1. Lakes are formed by surface water runoff build up, and reservoirs are formed by blocking up a river or stream (Fun Fact, there are no natural lakes in Georgia. All are reservoirs).  US lakes are used for both recreation and for water sources. Common contaminants are organic ones like algae, chemicals and metals, and occasionally bacteria and parasites. Red flags for lakes and reservoirs are algae blooms, areas with lots of boats and people, and if you can see a film on the water. It is usually also better to collect water for consumption from a deeper part of the lake.
    3. Rivers, Streams and Creeks
      1. Formed by precipitation runoff. Used in the US for both recreation and for water sources. Common contaminants are chemicals, metals, parasites, and bacteria. Red flags are mucky water, visible sewage or drainage pipes, and areas with high numbers of people. As a general rule fast moving water is usually safer.
    4. Rainwater Collection
      1. Rainwater collection is done with some sort of collection system that gathers rainwater in a collection reservoir. These are used for personal use. While some states have laws prohibiting rainwater collection, but Georgia doesn’t. Common contaminants are chemicals from acid rain, bacteria, and parasites. Red flags are film on the water and visible parasites and insect larvae.
    5. Seawater
      1. Salt water is normally not a safe water source due to the high salt concentration, but by using a process called desalination you can remove the water and make it safe. This is a method that is being used more and more around the world. Contaminants can include excess salt, parasites, and chemicals and metals from drainage and high numbers of people. Red flags can be high numbers of people, shallow murky water, and visible drainage pipes.
  3. Methods of Water Purification & which method is suitable for which type of the above water sources
    1. Boiling
      1. Boiling water is used for killing parasites and bacteria in the water. If the water is cloudy, then you have to let it settle and filter it through a clean cloth or coffee filter. After that, bring it to a boil then let it cool off. After that it should be safe to drink. This is the overall safest method, and usually the easiest to do in a survival situation.
    2. Chemical
      1. There are several different chemicals used,but all of them release some form of chlorine or iodine into the water to kill bacteria and parasites. To use, just follow the instructions on the bottle. This is one is good for all types of water sources.
    3. Filter
      1. There are several types of filters of different sizes, with some being for personal use and some for attaching to a water source like a hose or sink faucet. The main types of filters are mechanical filters, which use actual filters to filter out large particles and contaminants, biological filters, which use beneficial bacteria to remove chemicals from the water, and chemical filters, which use chemical purification in a portable container. Biological and chemical filters are usually used for home and aquarium filters, and mechanical filters are usually portable. This is one of the most commonly used methods due to you not needing to do much.
    4. Solar Still
      1. Used for desalination, you put salt water into the still, which then evaporates and leaves the salt behind, with the now fresh water flowing into a collection area. This one is really only useful for seawater.

Things to Show

  • LifestrawBackpacking Stove & Small Pot or Metal Cup
  • Materials to demonstrate a solar still
  • Purification Tablets
  • Troop filter hose
  • Anything else?


  • How about some mini “water purification” cheat sheets that could go in a wallet or be danlger behind the OA name tag. 
  • What if we bought and brought a couple lifestraws to give out as prizes at the end?
    ($20ish of Chapter Budget)


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