DIY Emergency Water Filtration

Emergency Water Purification

Sanitation of water during an


Regardless of the climate zone, a human needs to meet a certain level of water intake daily. Without proper fluid intake the body begins to show symptoms of dehydration. Symptom start with headaches, weakness and dizziness.

However drinking untreated water can further increase water loss. Water borne diseases such as dysentery, typhoid, and cholera are just a few of the problems we have to deal with. For this reason, it is a good idea to expand your knowledge of water purification methods. Fit the scope of this article we will cover several methods to purify water with supplies easily found in an urban environment.

We have covered the importance of proper hydration in several articles.

Usually the best methods to purify water are boiling and distillation. The methods covered on this article are for educational purpose only. It is not to be considered medical advice so please do your own research. We are covering purification methods that could be used in an event where a heat source may not be available. A water distiller can be built using common items such as a pressure cooker or tea pot. We will cover distillers in a separate article.

Note: It is very important to remove sediment from the water by filtering. Parasites and bacteria carried inside the solid (soil) particles are harder to destroy. Any time a chemical is used, the mix should be allowed sit for at least thirty minutes.

Water collection

Urban emergency water collection usually differs from wilderness survival methods. However, if we look around, there are still plenty of water sources. First, we must choose our water source wisely. We should try to collect from a water source is free of chemicals. During hurricane Katrina, the water supplies were contaminated with harmful sewage-related bacteria and toxic chemicals. During most urban situations, harmful toxins and chemicals will likely be found in the water supply. Second, we need to remove sediment or particles from the water. Third step is to properly treat the water to make it safe for consumption.

Important: The problem with urban water supplies is the possibility of chemical contamination. It is important that we keep this in mind when gathering water. Their potential toxic effects can cause adverse health defects on humans and animals. Its crucial to avoid long term exposure to these bioaccumulative toxins. Catching rain water is a good way to avoid harmful chemicals. This can be done with tarps and containers.

Some contaminants and their size in microns:


Contaminant size
Contaminant Size
Giardia lamblia 8 to 12 microns
Cryptosporidium parvum 4 to 6 microns
Bacteria (salmonella – E.coli 0.2 to 4 microns
Viruses 0.004 to 0.1 microns

This list does not include harmful chemicals such as Herbicides, Pesticides, Car fluids (oil,glycol,diesel), Metals, Rodenticides etc. All of which pose health risks to humans.

So what are some of our choices for water purification during an emergency? How we will purify the water depending on how much pre-planning has been done. Some people purchase water filtration systems before being faced with an emergency. If a water filtration system is unavailable, we will discuss possible methods of treatment.



* Filtration – Makeshift Water Filters

with the use of sand, charcoal, cloth and other materials some of the contaminants can be removed. Should be followed by boiling.

* Common Chemicals

this includes Flocculation by using military Chlor-Floc. Chlorine Dioxide, Iodine, Chlorine, calcium hypochlorite, and Potassium Permanganate.

* Manufactured Filters – ceramic filters or Makeshift filters

Manufacturers such as Katadyn and Berkey manufacture long term water purifiers. There are also companies that sell the ceramic filter element.

* Distillation

1.the volatilization or evaporation and subsequent condensation of a liquid, as when water is boiled in a retort and the steam is condensed in a cool receiver.
2. the purification or concentration of a substance, the obtaining of the essence or volatile properties contained in it, or the separation of one substance from another, by such a process.

* Boiling

Boiling is the surest method to make water safe to drink and kill disease-causing microorganisms like Giardia lamblia and Cryptosporidium, which are frequently found in rivers and lakes.
These disease-causing organisms are less likely to occur in well water (as long as it has not been affected by flood waters). If not treated properly and neutralized, Giardia may cause diarrhea, fatigue, and cramps after ingestion. Cryptosporidium is highly resistant to disinfection. It may cause diarrhea, nausea and/or stomach cramps. People with severely weakened immune systems are likely to have more severe and more persistent symptoms than healthy individuals. Boil filtered and settled water vigorously for one minute (at altitudes above one mile, boil for three minutes). To improve the flat taste of boiled water, aerate it by pouring it back and forth from one container to another and allow it to stand for a few hours, or add a pinch of salt for each quart or liter of water boiled.

If boiling is not possible, chemical disinfection of filtered and settled water collected from a well, spring, river, or other surface water body will still provide some health benefits and is better than no treatment at all.

Makeshift water filters

Water filters can filter and purify water using different methods.

* Ceramic filters
* Chemical treatment
* Systems that use both

Ceramic filters

Built of porous ceramic material, the ceramic filters remove bacteria by capturing the contaminants down to 0.2 micron range. It seems that EPA recommended filter pore size is one micron absolute. By using a pore size smaller than the viruses, bacteria or sediment, the water passes through the filter while the impurities are captured by the filter. Some bacteria and viruses will get past the filter, so it is still a good idea to boil or treat the water.

Chemical treatment

Water is often treated with chemicals such as iodine or chlorine in an attempt to kill the harmful bacteria or viruses. Some filters include a chemical treatment stage such as paper treated with iodine. Charcoal is often used to improve the taste of the water.

Water procurement in an urban survival situation such as an earthquake or hurricane can be tricky. The water can be contaminated with human waste, toxic chemicals, and pathogens.

We decided to build a filter that could be put together with items from a hardware store or even your backyard. Filters can be built using drink bottles, aluminum cans, and coffee cans.

Items used to build emergency filter:

* Sand

* Charcoal

* Sphagnum (peat moss)

* Cloth

* Moss

* Ultraviolet light

* Stones

Attempting to make a multistage filter we used sphagnum. After reading several sources claiming that sphagnum would release iodine into the water, we decided to give it the practicalsurvivor trial.

Iodine test

To properly treat water with iodine a level of 8 PPM (parts per million) is recommended. If the water has heavy sediment, the level would have to increase from 8 PPM to 16 PPM. Water is then allowed to sit for 10 minutes for full treatment.

Test 1 – First we want confirm that sphagnum will release iodine. Using iodine test strips we pour ten ounces of distilled water into a bowl. We drop the test strip into the water and leave it for 30 seconds. Iodine levels were not present.


We follow up by adding peat moss purchased at a department store. We tested with the sphagnum in the water and after removing it. The iodine test strips are color based so our concern was that the tint of the sphagnum would alter our test results.


Results Test 1 – 1.0 PPM after 30 seconds of exposure to the peat moss. Although 1 PPM is not enough to properly treat water, removing sediment from the water coupled with low level iodine should help to rid the water of some of the contaminants.

Test 2 – For our second trial, we built a multistage filter using a 2 liter soda bottle.


Filter stages:

1) Base layer closest to the mouth of the bottle – Green moss
2) Sphagnum
3) Charcoal and Peat moss mixture
4) Stones

Instead of allowing the water to simply go through the filter, we wanted to increase contact time with the sphagnum in hopes to increase iodine levels. The stages are set up to help remove sediment and possibly some of the parasite. Charcoal is used to improve the smell and taste of the water. Charcoal can also help remove some of the and bacteria.

Results Test 2 – Iodine Level 1 PPM. Increasing the contact time with the peat moss did not increase the level of iodine. Increasing the treatment time is part of the treatment.

All the testing was done with sphagnum purchased at a store. Testing with sphagnum moss from a peat bog might show a higher level of iodine.

Treatment with iodine from iodine crystals will get the proper iodine levels of 8 PPM. The chemical strips measure up to 5 PPM. This is a sample after only seconds of contact:

Chemical Water


* Potassium permanganate
* Iodine tincture
* Bleach
* Hydrogen Peroxide

Potassium Permanganate – (Condy’s Crystals) can be purchased at hardware stores. Sold as a water softener. Can be purchased in both powder and pill form (permitabs). This chemical compound has many uses from fire starting to water purification. Just a few crystals can treat a quart of water.

( aproximately 0.01% solution) 1 gram per liter (3 – 4 crystals)

Iodine tincture – Around eight drops per liter or about thirty per gallon

Bleach – Two drops of bleach per quart 1/8 teaspoon (or eight drops) of regular, unscented, liquid household bleach for each gallon of water

As per EPA suggestions:

Water purification by Bleach
Available Bleach Drops per Quart/Gallon of Clear Water Drops per Liter of Clear Water
1% 10 per Quart – 40 per Gallon 10 per Liter
4-6% 2 per Quart – 8 per Gallon (1/8 teaspoon) 2 per Liter
7-10% 1 per Quart – 4 per Gallon 1 per Liter



Hydrogen peroxide – (untested) During research we found recommended thirty-five to fifty percent concentration being used.


Manufactured Filter


There are several manufacturers that make water filters for the home. Although a personal unit could be used as a last resort, it may not be sufficient for a family. Larger models usually cost in the range of two hundred dollars and more. We found this filter from simply water and the monolithic dome institute for twenty four dollars plus shipping. The system is build using two 5 gallon buckets. We were able to build the system in under five minutes only using a drill.

The kit consists of one ceramic filter, pre-filter sock and a spigot. The proper washers and nuts are included with the kit.

The ceramic filter has a filtration efficiency is 0.5 micron and has been tested for removal capabilities of contaminants such as Cryptosporidium, E. Coli, Vibrio Cholerae and will also help remove chemicals and poisons such as Arsenic, Pesticides, Lead and Aluminum. A filter such as this one would have been an excellent source of water during hurricane Katrina.


Filter performance:

* Flow rate / Up to 1 gallon of clean water per hour (gravity flow)

* Filter will accept water from floods, lake, rain, well, tap, river or stream

*Cleansable with clean damp cloth

* Once in use, filter will last 6-8 months

Filter construction was simple. We used a 1/2″ drill bit to make three holes. The spigot hole needs to be a little larger than half inch. One hole is drilled at the bottom of the clean water bucket (blue bucket), one hole on the lid of the clean water bucket and one hole at the bottom of the unclean water bucket. More details on this video:


We used a blue bucket as our clean water bucket and a white bucket for the contaminated water. (for illustration purposes) The spigot allows us to access the clean water without having to open the system. Note: Test the unclean water bucket for leaks before using the system. We would not want the contaminated water to drip into our clean water supply.


The lid on the clean water bucket will need a hole to allow the water to drip down.



The top bucket (white unclean water) bucket will need a hole at the bottom center. This will allow us to push the filter through and for the water to work its way through the ceramic filter.


We installed the pre-filter sock to protect the filter during installation. It would be a good idea to use a piece of cloth to help filter some of the sediment out of the water if possible This should help ensure longer filter life. The filter can be cleaned using a damp cloth.


Removal Capabilities

Removal capabilities as follows:

* 99% Arsenic 5 and 99% Arsenic 3 (special order)
* 99% Hydrogen Sulfide (H2S)
* 95% Chlorine and Chloramines
* 98% Aluminum
* 96% Iron
* 98% Lead
* 90% Pesticides
* 85% Herbicides
* 85% Insecticides
* 90% Rodenticides
* 95% Poly Aromatic Hydrocarbons
* 99.999% of particles larger than 0.5 micron (Staffordshire University Labs)
* 99.7% of particles larger than 0.3 micron (Staffordshire University Labs)
* 98% of particles larger than 0.2 micron (Staffordshire University Labs)
* 100% Giardia Lamblia
* 100% Cyclospora
* 100% removal of live Cryptosporidium (WRc Standard)
* 100% removal of Cryptosporidium (NSF Standard 53 – A.C. fine dust)
* 100% removal of E. Coli, Vibrio Cholerae (Johns Hopkins University)
* 99.999% removal of Salmonella Typhil, Shigella Dysenteria, Kiebsiella Terrigena

We will be running testing on the filter and hope to one day test filters from some of the larger manufacturers as well.

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