In this article, I assume that you have NOTHING to clean your water: no tablets, bleach, water filter, etc,…
Water is essential for human health, in particular in emergency situations.
How is water contaminated?
- Leaking septic tank or latrine
- Contaminated water surface infiltration of wells and sources
- Collecting water with unwashed hands and/or dirty containers
- Animals using the same water source
- Items that fell into the well
However, even if the water you collected is clean, inappropriate health practice could contaminate it:
- transportation from source to home in dirty containers
- Keeping water at home in opened and/or dirty containers
- Handling water with dirty utensiles or dirty hands
Water can be contaminated after each step!
Here is a checklist to know if water could be contaminated:
- Does the water look clean?
- Does the area around water seem clean?
- Do storage and handling of water are appropriate?
- Do the persons have good health practice habits?
If you answer no to one of this question, you should’nt drink that water.
HOME WATER TREATMENT AND SAFE STORAGE
Filtering water is an important first step. If you do it correctly, it will improve all the different methods presented below. By filtering muddy water (or water that doesn’t look clean) with a thin and clean cotton fabric, you can remove a great part of suspended solids and insect’s larvas.
A simple test to know if the fabric is good is using it to filter water. If impurities don’t go trough it, it’s appropriate. It shouldn’t be transparent or too thick, because it will take more time to filter.
By washing the fabric between each use, you keep your filtering efficient.
Only filtering is not enough for making a contaminated water drinkable, but it facilitates home water treatment.
If water is clear but could be contaminated, it should be desinfected.
I am going to detail 2 methods:
- Solar desinfection
Boiling is a traditional way to treat contaminated water. If used correctly, it provides drinkable water when you have no other options.
But boiling water has pros and cons.
Boiling will kill all pathogenic germs
Boiling is a method easy to do
You need a kilo (2 lbs) of wood to boil 1 liter (33oz) during 1 min
Your water will not look less cloudy after boiling
Boiling has not a durable effect. If not stored properly, it could be contaminated again. Boiled water should be used in the next few days after boiling.
The temperature of boiling must be high to be efficient. If you only see vapour, it’s not boiled!
You should see big bubbles when boiling.
How much time should you boil water?
- Low altitude: 1min with big bubbles
- High altitude: 3min with big bubbles
If you expose water to the sun, it will kill most of germs. This method is more efficient with high temperature.
A simple way for treating water is to expose to the plastic/glass bottles filled with water. Each bottle should stay at least 3 days on direct sun. You should double the time of exposition if there are clouds or if the water is murky.
Personal tip: If you don`t have a bottle, you can use a clean and transparent plastic bag. Use a undulated sheet metal for better efficiency.
Solar desinfection has also pros and cons
Very easy to do with common items
If exposed enough time to sun, it will kill most of bacterias
Solar desinfection has not a durable effect, so water could be contaminated again if not stored appropriately
Water should be drunk in the next few days
A slower method than the others and the weather must be sunny
Now, we are going to detail a good method to remove mud from water.
If your water is muddy, you can let it decant for a few hours. It will separate water from sediments. Filtering it with a piece of fabric as described above will increase the efficiency of this process.
Notice: Decantation is not enough for cleaning water. It must be desinfected to remove pathogenic bacterias. But this process will increase the desinfection’s efficiency.
The 3 Containers Method
This method consists in reducing the quantity of impurities and pathogenic germs by pouring water in a first container, and waiting that the sediments are deposited at the bottom. Then you transfer the water from the first container and after from the second to the third one.
It should be your daily routine when SHTF.
Every day, when you bring water to your house:
- Drink water from container 3
- Pour slowly water from container 2 to 3
- Wash container 2
- Pour slowly water from container 1 to 2
- Wash container 1
- Pour water from your water source (bucket 4) to container 1. It’s better to use a fabric to filter that water before. Let water in containers for a day and repeat the process.
Drink water only from container 3. This container can be washed and sterilised by boiling it regularly.
Personal tip: By using a flexible tube to siphon off water from one container to the other, you reduce sediments blending. You can improve this method by filtering water with a piece of fabric each time you transfer a container to another.
This method is temporary and useful in an emergency situation when you don’t have other option until you can use another method for cleaning water.
In an emergency situation, it’s possible that you won’t have 3 containers. You can use only 2 containers instead of 3 but the efficiency will decrease. The water should stay longer for impurities to be deposited and pathogenic germs to be killed.
The 3 containers method has also pros and cons.
This method reduces hugely the quantity of bacterias and impurities
It’s very cheap and easy to do. You only need local resources.
This method doesn’t remove all the pathogenic germs. Desinfection is necessary to avoid any risk of disease.
4. Sand Filter
Sand filtering is a very simple and quick method of pretreating water. It reduces the quantity of impurities and make desinfection more efficient.
Pour water in a container with sand and gravel. Water flows by a tap or a hole to a storage container.
GOOD PRACTICE FOR HANDLING AND STORING WATER
In an emergency situation, people will use containers they already have. Do with what you have.
Encourage your family to wash and tap containers. Place them out of reach of children.
It’s better to use different containers for storing and collecting water.
Always wash your hand before handling drinkable water. Stockpiling/Making soap or hand sanitizer should be one of your priority.
Source: Red Cross and Red Crescent