How to Clean Your Drinking Water

Most of us take our water for granted. The privilege of turning on the tap or getting a cold glass from our refrigerator door is something most of us don’t even think about—until it is taken away. There are several alternative methods to purifying water, some more drastic than others. The following is intended as a guide to several of the most common methods.

Sterilization by Boiling

Boiling is the most recommended method of water purification if there are contaminants in the water.

What You Will need:

  • Large pot
  • Source of heat
  • Table salt (optional)
  • Container to store your water

The Process:

  1. Place the desired amount of water in the pot, and bring to a full rolling boil over high heat.
  2. Let the water boil for 1 to 3 minutes (at higher altitudes, your water should boil for at least 3 minutes).
  3. As the water boils, if any debris, residue or foam comes to the surface, remove.
  4. As the water boils, you may add a pinch of salt to improve the taste.
  5. Allow the water to cool before drinking.
  6. The boiled water may be stored in a clean container (do not reuse the one which you used to get the water initially as it may contain contaminants and/or bacteria)

Sterilization with Bleach

Again, this method is recommended for water that is contaminated and should be used only if boiling (which is the preferred method) is not an option. Always consult a professional when handling the potentially dangerous chemicals in the following set of instructions.

What You Will Need:

  • Gallon or half gallon containers for water
  • Liquid chlorine bleach
  • Eye dropper
  • Teaspoon

The Process:

  1. Assess the clarity of your water as different amounts of bleach will be used for water that is clear vs. water that is cloudy.
  2. Use bleach that does not contain dyes or perfumes (i.e. such as lemon scented bleach). Check the label—in order to effectively kill bacteria, the bleach should contain 5.25% hypochlorite.
  3. If the water is clear, using the eye dropper, add 8 drops of bleach to 1 gallon of water (4 drops to a half gallon). If water is cloudy, add 16 drops to 1 gallon of water (8 drops for a half gallon).
  4. If you do not have an eye dropper, you can use a teaspoon so long as you use larger quantities of water, as follows: If water is clear, add 1/2 teaspoon of bleach to 5 gallons of water. If water is cloudy, add 1 teaspoon of bleach to 5 gallons.
  5. Shake or stir the water to disperse the bleach.
  6. Let the water stand for 30 minutes before consuming.
  7. DO NOT add more than the recommended amount of bleach; bleach at high levels can cause burns to your esophagus and stomach lining.

Iodine Tablets

What You Will Need:

  • Containers to measure and hold water
  • Purification tablets (available at most sporting goods and camping supply stores)
  • Powdered drink mix (optional)

The Process:

  1. Measure water to be purified and add tablets as per manufacturer’s directions.
  2. Allow water to stand for 30 minutes before consuming.
  3. Be sure to follow product directions precisely as using too much or too little of the product can be hazardous to your health.
  4. DO NOT use Iodine tablets for water purification if you have a thyroid problem.
  5. Water purified with Iodine will have a peculiar taste to it. To make it more palatable, you may want to add powdered drink mix to it.

A Warning About Chemical Purification:

While chemical purification (using Iodine Tablets or Bleach) may remove most contaminants from drinking water (including Giardia), they may not fully remove Cryptosporidium (a nasty intestinal parasite) from the water. Only boiling will do this.

The EPA offers information about emergency water purification on their website.

Water Filtration Systems

In-house water filtration systems are another way to purify your drinking water. There are many types and brands of water filtration systems. The following summary is intended as a basic overview of some of the more popular types of water filtration systems available and is by no means a comprehensive guide.

Pour-Through Containers

These are the simplest type of water filtration system, and also generally the least effective in removing contaminants, although it will improve the taste of your water. Basically, the water you will drink is placed in a container with a filter attached to the spout. The water is run through certain fabric-type materials that screen out particles and some contaminants.

Faucet Filters

Many companies (such as Brita and PUR) make filters that attach directly to your water faucet, or under your sink. These filters generally run the water through a ceramic screen to remove contaminants. Most of these systems use a molded block of activated carbon, a material proven to improve taste of water and remove certain common contaminants. When buying this type of system, it is recommended that you look for one that uses “absolute one micron filters.” These filters are the most effective in removing contaminants, including Cryptosporidium (that nasty and stubborn intestinal parasite mentioned above).

Whole-House Systems

These water filtration systems are the most elaborate types of water filtration available and are designed to filter all the water that comes into your house. These systems are varied, and use different types of technology (i.e. Distillers, Reverse Osmosis, Water Softeners) to filter contaminants from the water supply that enters your dwelling. There is much debate over which type of system is most effective. For instance, the distillation process heats water to a boiling point, removing many contaminants, but also removing the natural minerals and vitamins in the process. Reverse osmosis forces water through a semi-permeable membrane that filters out many types of toxins and are very effective, but these filters may also use about three times as much water as they treat, causing some to view it as wasteful.

How to Choose the Right System

When choosing the right system for your lifestyle, there are several important considerations:

  • Purpose: Consider why you are seeking a water filtration system. Is it simply a matter of taste, or are you concerned that there may be harmful contaminants in your water?
  • Cost: Consider not only the cost of installing the water filtration system, but also the cost of maintaining the system (i.e. purchasing replacement filters, etc.).
  • Certification: Certification comes from three different primary organizations, NSF International, Underwriters Laboratories and The water Quality Association. No mater what system you choose, it should have a certification from at least one of these organizations.
  • Research: Make sure you research each system you are considering thoroughly before making your decision. Each type of water filtration system has it’s advantages and disadvantages, and you should be familiar with the different types and brands available but also the pro’s and con’s of each.


  1. Alfred says:

    After water is boiled (bubbling) thoroughly, some quantity of chlorine may remain in the water, (in some places excessive chlorination is given where treated water is carried over long distances) and this water will spoil the taste of the water, tea, coffee, etc. Try to get dry pine cones, or pine wood, burn this and get the charcoal. Break the larger pieces into smallish bits, (not dust), and put this into the boiled water. Let it stand for a little while. The charcoal will absorb the chlorine and give the water a better taste, and make it clearer.

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