Disinfection with Potassium Permanganate

Potassium Permanganate is a very versatile chemical. It can be used for disinfection, removing hardness, removing iron and manganese. It has another health related use, it can be mixed into a paste and used as a topical salve for athlete’s foot (or similar problems). As a result potassium permanganate is a great addition to any emergency preparedness supplies.

Potassium Permaganate has the chemical formula of KMnO4, and it comes as a deep purple dry powder. This chemical is a very powerful oxidizer and it should not be stored anywhere near acids or fuel sources or it could result in fires, explosions and/or toxic gases being formed. Explosives is another use of this chemical (one which I will not be explaining here). This chemical can be stored for over a year if it is kept clean and dry and in a sealed container.


Before touching the dry powder, make sure you wear a particle mask (ideally a N95 or better). This chemical will irritate the airways if inhaled directly. Also the powder once mixed with water becomes a powerful dye. It will stain clothes permanently, stain skin temporarily and cause corrosion on any metal or masonry it touches. Anything that becomes exposed to a potassium permanganate solution becomes brown, a similar shade of brown to a henna tattoo.

To make a topical treatment with KMnO4 mix the dry powder with water until it has the consistency of playdoh. Apply the mixture on the affected area and repeat as necessary. Remember that I am not a doctor and I am not giving medical advice. I am only outlining that this chemical CAN be used for medical purposes. Whether or not you SHOULD use KMnO4 for medical applications is not something I can tell you.


Potassium permanganate is very similar to sodium hypochlorite in the sense that they both disinfect water through oxidation. Disinfection of drinking water can be achieved by adding it to the water until the water turns pink. The pink in the water is the residual potassium permanganate. Meaning that there is nothing left to use up the chemical and any bacteria has been used. Think of the pink water as being similar to the point where you can smell bleach when using sodium hypochlorite for disinfection. Just like with the smell point of bleach has surpassed the disinfection point, you do not need to keep adding KMnO4 until you see pink. Disinfection has occurred well before you can see a lasting pink tint to the water. Using the color change is a simple and easy to remember method for disinfection of drinking water. And if the pink tint disappears at any time then you know you need to add more of the chemical to redisinfect the water.
If you want to avoid pink water and spend less money on chemicals you can buy a testing kit for manganese. Most kits can measure the residual levels of KMnO4 at levels well below the pink water threshold and well above the disinfection requirements.


For better results with disinfection it is best to filter the water through a greensand filter. Now this is not an indication of the color of the sand (it is actually black in color). Greensand is an activated filter media designed for removing iron and manganese through a process called ion exchange. The good news with a greensand KMnO4 combination is that the potassium permanganate will reactivate the filter media.

One thing to note is that potassium permanganate once added to water will make the water more corrosive. If the water is very pink it can also stain any container it is stored in. The pink water is perfectly safe to drink. I mean the water is not dangerous because of the pink coloring. It may however be dangerous for another reason or contaminant.

Another thing to note about KMnO4, is that if you add it to chlorinated water it will form a percipitate (solid). This is manganese dioxide, it is harmless except it will consume all the available chlorine in your water leaving you open to contamination from microorganisms.

With a few simple precautions KMnO4 is an excellent chemical to have on hand. It can be stored longer than sodium hypochlorite (bleach) and it can be added directly to the water unlike calcium hypochlorite. It also is very easy to see when enough of the chemical has been added. If there is a lasting pink tint that doesn’t disappear with time then the water has been disinfected.

When it comes to disinfecting your own drinking water, always be careful with the quality of chemical you use. They are not all created equal. The north american standard for chemicals used in drinking water is NSF/ANSI 60. Choose chemicals that meet this standard above ones that don’t. The will be significantly safer for your health and well being.

As with all my disinfection articles, I will remind you to always drink the safest water you can and combining treatment techniques is the best way to achieve safe drinking water

Can I use a storm-water pond as a back-up source of water?

Storm-water ponds are the closest alternative source of water for many people living in urban areas. In an emergency this source of water may be all that is available to you.  Eventually any water you have stored will be consumed and the water in a storm-water pond may be the difference between life and death.  With the proper treatment your local storm-water pond can be a great backup source of drinking water.

Industrial storm-water pond (source: info.evergreen.ca)

Storm-water presents a unique set of challenges during treatment. Because storm-water ponds collect surface water, the water is exposed to all the contaminants on the ground in the catchment area. This includes but is not limited to pesticides and fertilizers applied to lawns, motor oil and gasoline leaking from vehicles and litter like cigarette buts. It all ends up is the storm-water pond. Those chemicals are already in storm-water ponds on a normal day. During an emergency there may be additional contamination from sewage runoff from an overloaded or broken sewage system. The water in the pond will also contain all the microorganisms like ecoli, giardia and cryptosporidium normally in surface water. Any one of these will make you very sick if you get infected with them.
Finally, there will be high levels of nitrates in storm-water ponds. Too much nitrates consumed by young children can cause blue baby syndrome.

The first step in treating water from a storm-water pond is straining. Straining the water through a cloth or loose sand filter will remove large particles (ones you could pick up with your fingers). Remove as much of the suspended particles from the water as you can. Straining the water first will extend the life of your proper water filter.

If you have a clarifying agent like aluminum sulfate, this is the best time to add it to the water.  It will make contaminants too small to be filtered become attracted to each other and become significantly larger.  Larger particles are easier to remove from the water. Let the water sit still for at least 30 minutes without disturbing it.  All the newly formed large particles (called floc) will sink to the bottom.  When you take the water from this container, make sure you leave the majority of the settled material at the bottom of the container.

Urban Storm-water pond (source: greenbmp.blogspot.com)

The next step is to filter the water. Filter the water even if it looks clear, the human eye is five times too weak to detect dangerous levels of particles. Filter the water at least once through an activated carbon filter. Activated carbon is known to remove many different chemicals from water including pesticides, chlorine and fluoride. Activated carbon is not the same as charcoal. Charcoal is similar, it can remove toxins from water but it is nowhere near the efficiency of activated carbon.

The third step is oxidation. Oxidation will help with disinfection as most disinfectant chemicals are also oxidizers. Chemicals like sodium hypochlorite and potassium permanganate are both oxidizers and disinfectants. Oxidation will break down many of the remaining contaminants and inactivate many of the remaining bacteria. Keep adding the oxidizer/disinfectant till you can detect a residual after 20 minutes. The 20 minutes is the minimum you should wait for a gallon of water. Wait longer for larger volumes. This is because oxidation is a chemical reaction that isn’t instant. It needs time to complete the reaction.

The fourth step is to filter the water again. Filtering again is necessary because the disinfection/oxidation step will create some potentially carcinogenic byproducts. We filter before oxidation to minimize the amount of chlorine (or other chemical) and to limit the possibility of forming dangerous byproducts. We filter the second time to remove any byproducts that have been formed.

The final step is to boil the water.  This will help with disinfection, but the main goal of boiling at this point is to remove any volatile chemicals.  Any chemical with a boiling point lower than water will be removed after boiling.

A note about disinfection.  If all of these steps are followed there is no need for a step dedicated for disinfection.  Between the oxidation and the boiling of the water any microorganisms will be inactivated.  If you are storing the water for a long time then add some sodium hypochlorite for a residual disinfectant.  The residual disinfectant will prevent the water from becoming recontaminated before you drink it.

One additional possible step is to aerate the water.  Ponds are frequently stagnant.  Stagnant water is green with algae, it smells bad and tastes worse. After the water is made potable, transfer the water back and forth between two glasses. This adds oxygen to the water and will make the water taste better.

This may seem like a lot of work for something as small as a storm-water pond.  What I have described are the basic steps to turn the potentially toxic water in the pond into clean and safe drinking water.

Non-Chlorine Pool Chemicals: Safe for Drinking Water?

When an emergency or a disaster strikes and you run out of clean drinking water, a clock starts counting down.  Three days is all that this clock has.  Three days is how long it takes a healthy adult to die of dehydration.  This journal entry is a continuation of my article on Pool Chlorine and Drinking Water. Many people with pools believe they can use this water as a back up source of drinking water,  whether or not that belief is a sound one is not always a simple answer.  While chlorine is by far the dominant disinfection agent used in pools there is a growing trend away from using chlorine.  In the first article (linked to above) I covered all the common types of pool chlorine chemicals.  In this article I will discus some of the other chemicals used in pools, and how they affect drinking water in survival situations.  I always recommend drinking the safest quality water you can get, clean untainted water that has been properly disinfected is always at the top of the list.  The advice that follows is for those situations where pool water and pool chemicals are better than tainted and untreated water.  That decision is something that everyone has to make for themselves when the emergency hits.

Salt Water Pool: (image source http://salt-water-pools.com)

Saltwater pools are the fastest growing among the alternative disinfectants. Saltwater pools may be safer to swim in, but are much more difficult to treat. If you were to drink the saltwater from a pool you would start an acceleration of the dehydration process as it takes more water to remove the salt from your body. To put it another way, it takes over one liter of water to remove one liter of saltwater. There is only one that can effectively remove salt from water is distillation. Boiling will not remove any salt at all. In fact you can boil it till all the water is gone and all the salt will remain in the pot. Distillation is the boiling of water and collection of the water vapor and steam. Then the cooling of the vapor and steam back into water into another container. Continue reading

Septic Tank Management

Homeowners are responsible for maintaining their septic systems.  It not only protects the investment in your home, but also protects your water supply and those of your neighbors.  You don’t want to be the cause of major ground water or surface water contamination because of a malfunctioning septic tank.  The liabilities are potentially huge and your homeowners insurance may not cover you if you didn’t do the required maintenance.   It will also make selling your home difficult,  I personally have walked away from houses I wanted to buy because the septic system was not in proper working order.

Septic tank management can be very simple. If the tank has been properly constructed and installed very few interventions will be necessary and the interventions will primarily be inspections.  The major components of a septic system are a collection pipe from the house, the holding tank, and the drainage system (usually a field).  The collection pipe is the final pipe leaving the home that contains all the household waste water.  This part of the system is identical for people connected to a municipal sewer except for where the pipe goes. Continue reading

Water Quality Myths

There is a lot of misinformation available about water quality.  If taken as true in the wrong situation they could be very costly, they might even cost you your life.

The first myth I want to mention is the belief that ground water is pure. See my article on why I dislike the term “purify” when it concerns water.  I have heard this over and over again, “if we were all drinking ground water we wouldn’t need all these chemicals and we would all be healthier”.  This simply isn’t true.  Ground water does contain bacteria, it is usually free from pathogenic organisms, but that is not guaranteed, and if your system isn’t used to the specific bacteria in the ground water they may still make you a little sick.

The second myth I want to squash is the idea that sunlight, specifically the ultraviolet radiation will kill bacteria.  Let’s think about this for a second.  Using a lack of common sense, sunlight disinfection appears to be true.  UV kills bacteria and the sun emits UV radiation sounds like a win-win scenario.  However with a lot more common sense and some education behind it, it becomes apparent that all the lakes and rivers on the surface of the earth are exposed to sunlight.  If UV from the sun disinfected water, there would be no microscopic life in our water and because this is the bottom of the ecosystem, there would be no ecosystem at all.   Continue reading

Disinfection with Calcium Hypochlorite

This journal entry is a continuation of my series of entries on disinfection of drinking water.   Please read the following linked articles first,  Introduction to Disinfection and Disinfection with Sodium Hypochlorite.  I have covered a lot of background information already, which you will need to fully understand this journal entry.    Go ahead, I’ll wait.

Calcium Hypochlorite, Ca(OCl)₂ is a solid chemical used as a disinfectant and bleaching agent. It is used to store chlorine for long periods of time without having to resort to chlorine gas, which is extremely dangerous if not handled properly.  If stored is a room temperature environment away from moisture, temperature extremes and direct sunlight, calcium hypochlorite can last up to a year without serious degradation.  Beyond a year the chemical will become weaker with time.

Calcium hypochlorite is very similar to sodium hypochlorite.  The biggest difference is Continue reading

Well Disinfection: What To Do After Contamination Occurs

It is a common misconception that ground water is safe from contamination. This simply is not true. Wells can easily become contaminated if the proper maintenance isn’t taken and even with proper maintenance they can become contaminated during an emergency like a flood. See my article on Ground water and Wells for the proper maintenance of wells to prevent contamination.

Wells can become contaminated two separate ways. The first one is harder to control.  It happens when the entire aquifer becomes contaminated. This can happen when there is an environmental spill of something (anything really) that percolates into the aquifer in or around the recharge area. This could be on your property or a hundred miles away. It all depends on the aquifer.

How Contamination Enters A Well: From: http://www.health.gov.on.ca

Continue reading