How to Remove Chemicals From Drinking Water in an Emergency

Knowing how to remove chemicals from water is an essential skill that might come in handy if the tap water becomes undrinkable. Think of any disaster scenario, chemical spill, or hurricane, and there is a run on bottled water at the supermarkets. Learning to purify water is even more critical for people living in rural areas that do not have immediate access to supplies. 

Chemical spills do not just happen in far-off countries but can happen closer to home than you might think. The ongoing contamination problems in Flint, Michigan and West Virginia are just two examples affecting millions of people.

Contaminated water is not something that you should be drinking, especially if it contains heavy metals (lead) or pathogens (Giardia). 

What would you do if the water was contaminated? Let’s find out some of the easiest and most effective ways of safely treating your water.

How to Remove Pollutants from Contaminated Water?

According to the CDC, the most effective way to remove pollutants from contaminated water is by boiling water.

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1. Boiling Water

Boiling water should be done for at least 1 minute and brought to a rolling boil. If you are at a higher elevation, you need to boil the water longer due to decreased oxygen levels.

The CDC recommends that water be boiled for 3 minutes if over 2000m or 5,562 feet.

2. Chemical Disinfection

Common Household Bleach

Using a few drops of regular old household bleach is an easy, cheap, and effective way to kill many different forms of bacteria. Using bleach as an emergency water purification technique should be done only if it is impossible to boil water.

Ensure that the bleach does not have any added cleaners or scents. Look for bleach that contains sodium hypochlorite, usually in 6% or 8.25% concentrations.

Iodine and Chlorine

Similar to bleach, iodine and chlorine remove pathogens. You can find iodine and chlorine tablets are your supermarket or online. Usually, they come in the form of soluble tablets (1 tablet per liter) or liquid drops (5-10 drops per ltr depending on concentration).

Be sure to check the concentration and proper dosage.

According to the CDC, Disinfectants can kill most harmful or disease-causing viruses and bacteria but are not as effective in controlling more resistant organisms, such as the parasites Cryptosporidium and Giardia

3. Filter Water

There are many ways that you can filter water. The simplest and easiest is to use a hand-pumped water filter.

The CDC suggests picking one that has a filter pore size small enough to remove parasites.

Look for a filter with a pore size of 1 micron or less.

Additionally, you can add chemical disinfection such as bleach, iodine, or chlorine after you filter the water to kill any other additional pathogens.

Here is a list of some of the best water filters that we have found.

Other Ways to Remove Chemicals from Water

Distilling Water

Distilling water also removes pollutants; though not widely used, it is still effective. It works when the chemical’s boiling point is higher than the water’s, meaning that the water will boil off into steam to be collected – which leaves the contaminant residue left over.

You can either purchase a still or make a simple one using a couple of pots with a heat source.

Will distillation remove all chemicals from drinking water?

Overall, distillation is one of the best ways to get clean drinking water.

The basic idea is to boil the water and capture the steam as it condenses in a separate container. Minerals and other water-insoluble contaminants become trapped in the original vessel. Chemicals with boiling points higher than water will not turn to steam and will stay in the original container.

One crucial bit of info is that you need to know the chemical’s boiling point is sufficiently above water’s boiling point.


Distillation eliminates germs, viruses, and parasites. If done correctly, distillation can remove 99% of pollutants, but it can’t be relied on to eliminate compounds with a boiling point close to or below the water temperature. For example, Toluene and Benzene have lower boiling points than water, which boils at 212 F or 100C.

What this means is that those pollutants with a boiling point under 212 Fareignhet are left in the water. Distillation is excellent for removing most contaminants, but to be 100% effective, you need to know what type of pollutants are in the water.

Activated Charcoal to Remove Chemicals from Water

Activated charcoal works by absorbing pollutants similar to a sponge. Activated charcoal is different from plain charcoal found in many other water filtration systems. Activated carbon has a larger surface area with millions of tiny pores on its surface, allowing the compound to absorb whatever it comes into contact with.

Activated charcoal can filter:

  • Chlorine
  • Chloramine
  • Tannins
  • Phenol

And can’t be used to filter:

  • Ammonia
  • Nitrates
  • Nitrites
  • Fluoride

Activated carbon derived from wood, bamboo, coconut shell etc…Small pores and increased surface area is what give it super absorbant properties. The pollutants are attached to the carbon through the reaction.

While this approach eliminates chemicals, it does not kill germs, viruses, or parasites, so you’ll need to use other disinfection methods.

You can find some water filters that use activated charcoal together with a micron water filter. Micron water filters offer a water filtration system with tiny holes smaller than 1 micron. Most protozoa and bacteria are larger than 1 micron in diameter and get caught in the filter.


Getting adequate drinking water is the most important thing to consider in an emergency scenario. You can survive weeks without proper food, but only days without adequate drinking water. If you drink the wrong water in an emergency situation, you risk making a bad situation worse.

Note: Before relying on any purification or filtration technique, check with local water or city authorities after any chemical spill or emergency involving contamination of your water source. This post is for general information only and should not be considered your sole source of information.


[1]Food and Water in an Emergency.

[2] Separation by Distillation.

[3] Basic Concepts of Steam.

[4] Difference Between Distilled Water and Boiled Water.

[5] Activated Charcoal and How It Works.

Photo by mrjn Photography/Unsplash

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