A survival water filter is probably the most important item on your survival list for when a disaster happens. Most people think that they will rely on boiling water if it is contaminated, however.. consider that to get rid of most nasties you will need to bring it to a rolling boil. The guy at our local water filter shop reckons up to 20 minutes boiling to get rid of the majority of pathogen spores. This is only practical if you have lots of access to woods or if you have a large stock of gas bottles. In Africa, the aid agencies estimate it takes 1 kg of wood to boil 1 litre of water.
But consider the following scenario:
A hurricane has blown through leaving thousands of power poles down. Unfortunately the subsequent flooding heavily contaminated the local water reserves and may have broken some of the local water supply system. Gas lines are affected and leaking. This means you will be without electricity or gas and unable to boil water.
How much clean drinking water per person per day?
A good guideline is a minimum of a gallon (3.8 liters) per day per person. Say you have sensibly stocked at least 100 water purification tablets will treats about 26 gallons (100 liters) which will last about seven days (168 hours) for 4 people. Note that we are only talking about drinking water, hopefully the contaminated water can still flush the toilet and for other purposes. Faced with this questions I wanted a portable gravity fed system that can be used at home but also quickly transported if requested to leave our home.
Note: I already have a under-sink water filter system installed after a giardia and cryptosporidium scare a couple of years ago and there were no disasters, no floods, The local treatment plant got it wrong and we all found out because someone leaked the water testing results – I have learned not to assume that the local water authorities are always going to get it right.
By the way, I installed it myself, without hubby’s help, just needed to borrow a big enough drill bit from the neighbor to make a hole in the sink for the outlet tap (I am a woman, trying not to be sexist but just to emphasize you can have safe clean great tasting water for your family with minimal effort). The biggest side benefit is the improved taste and hence more drinking of water by my family. During a disaster if the local water supply is not disrupted, only contaminated – presumably not with industrial chemicals, this is an excellent first line of protection. Consider a inexpensive highly rated system system like Watts Premier Uf3 3-stage Ultra Filtration System
But back to the topic in hand
Best survival water filter key requirements
- effective – remove as may nasties as possible – passing the NSF standard and ensures bacteria does not grow over time
- portable – small and light
- efficient – at least a gallon (3.8 liters) or so and hour
- cheap -I hope to never have to use it so the cheaper the better
So I happened upon the cleanwater bag kit
Their clean water kit uses one the most highly regarded survival water filters made by British Berkefeld (makes Berkey water filters in the US). The company dates back to 1827 when developed its first filter for removing bacteria from Thames River which at that time was heavily contaminated with raw sewerage. These filters are in use by the Royal household and in over 150 countries. Okay, so we are in good company.
Checking against requirements
Effective survival water filter
A key strength is that their ceramic water filters are silver impregnated and stops bacterial growth, they are self sterilizing. So not only does it remove more than 99.99% of cryptosporidium, giardia, E. coli, ibro Cholerae, Salmonella, Dysenteria but it does not have re-contaminate the water. Many ceramic filters are unable to pass the NSF testing standards because they are unable to pass the NSF material extraction test.
Pretty small when you need to transport it say about 3 x 3 x 10 inches when rolled up and weighing only 0.4kg.
Efficient Survival Water Filter
Does 5 liters an hour (a gallon and a bit) I know some pumps are faster but I want a passive gravity fed system.
It cost $70 – that’s pretty average but what makes it really inexpensive is that a Berkefeld ceramic filter lasts about 12 months in continual use. These kits are used by aid agencies around the world. They even supply you with some scrubbing material to clean the outside of the filter if you are filtering really dirty water. I would pack a pair of ladies stocking to act as a pre-filter to filter out the really big bits of dirt.
How to Construct your own Survival Water Filter Cheaply
This system is extremely adaptable and can be transformed into a static kit – which got me thinking, as these are only available in Australia, France, Uganda and the United Kingdom at the moment, But you could just buy the world renowned 7″ British Berkefeld Ceramic Water Filters for Big Berkey (called Berkey in the States) and construct your own cheaply with a bucket and some PVC hosing.
You melt a small hole in a bucket, put the threaded outlet through (put the rubber on first). Use the threaded wing nut to secure it to the bucket and attach some plastic pipe to guide or stop the flow. The minimum order is 2 filters and they each come with a rubber washer and wing nut so you can attach it to a bucket with a hole or a thick PVC bag The filters are threaded. (This same system then for half the price I paid for it)
A similar system is the Katadyn Base Camp Water Filter which uses the Katadyn Replacement cartridge for the Hiker or Pro – note that the Katadyn Hiker is the best selling micro filter in the United States and great for 1 or 2 people with a capacity of 750 liters. The cartridges last less than the Berkey filter and no self sterilization but still an excellent choice.