Making rain water drinkable?

[Vortex2]

Hi,

I don't fancy drinking rainwater .. it's likely to be contaminated.

Can anyone recommnend a cheap filter etc to make it drinkable?

Thanks.

[adam2]

In a remote rural area, rainwater is probably drinkable without treatment, do not drink the the water that first runs from the roof or other catchment as it will contain dust and bird droppings. Use a "first flush diverter" whereby the first XX litres of rain water is run to waste and the remainder collected in a tank. Fit a strainer to reject leaves and other debris.
Water from a tank or cistern made from cement or concrete tastes better than that from a plastic or metal tank.

For a more cautious approach, then either chlorinate the water or use a gravity filter.

Chlorine tablets may be obtained from https://evaq8.co.uk/Water-Purification/ ... -bulk.html Cheap and simple and used as directed will kill almost all micro organisms. Although cheap in bulk they do need continual resupply. They only kill microorganisms and will not remove other pollutants such as heavy metals or radioactive fallout. The water has an objectional taste so more suited to short term emergencies than routine use.

For longer term use a gravity water filter is best, such as https://doulton.com/british-berkefeld-6 ... ex-display The filters are very long lasting but do not last forever, keep plenty of spares. The stainless steel housing/water container should last forever.
These filters remove all common contamination, including fallout.

Boiling is simple but tedious and uses significant fuel. Boiling kills micro organisms and removes SOME hydrocarbon pollutants but is useless against heavy metals or fallout.

Ultraviolet treatment kills micro organisms but needs electricity and replacement lamps. Kills micro organisms but no good against fallout or heavy metals.

[BritDownUnder]

I will have to check out those water filters from Doulton.

I collect rainwater and use a first flush system - amazing how much sludge gets in there. A lot of people drink it in Australia straight from the tank with minimal filtration. Something that is worn as a badge of pride.

I hear there is a way of using a system of layers of sand and soil as a means of filtration that is supposedly quite reliable.

[Vortex2]

How many litres do you think you can process per filter?

[adam2]

How many litres do you think you can process per filter?

6 Months normal household use is suggested. When the flow rate is reduced, the filter may be cleaned, but only a limited number of times. Each cleaning removes the surface of the ceramic filter, and when too much is removed it becomes less effective.
They used to come with a plastic measuring gauge, when the filter fits through the hole, you need a new one.

I removed one of the two filters from my filter housing, replacing this with a blanking plug. This halves the flow rate but means only one filter to replace after 6 months rather than two. AFAIK the suggested 6 months is calendar time related, not flow related.

[mr brightside]

Streams are very useful, depending on where you live obviously. One myth is that brown bog-drained water is dirty, it's not, it's brown from the peat in the same way that a cup of tea is brown. Up in Stainmore in the 80s as children we used to bath in brown water, before the arrival of mains.

[emordnilap]

Ultraviolet treatment kills micro organisms but needs electricity and replacement lamps. Kills micro organisms but no good against fallout or heavy metals.

I collected dozens of 5 litre plastic water bottles, filled them to capacity (screwing the lid down whilst squeezing them so no air in in them) and stood them for several days in good sunshine. I then stored them in a dark shed.

About seven years later, I tested one and it's fine, tastes ok, no algal growth showing (which does happen with our well water if not UV treated) and is my 'emergency' supply for power cuts. There's about enough water for two for a month without alternative sources.

[kenneal - lagger]

...........
I hear there is a way of using a system of layers of sand and soil as a means of filtration that is supposedly quite reliable.

Much of London's water supply is sand filtered. It comes from the Thames west of London, hence the saying that London's drinking water has been passed by at least seven people before a Londoner drinks it, and is pumped around the city to the Coppermills water filtration plant in Walthamstow where it first goes through a settlement tank to remove most of the sediment and then is distributed over sand filters before being sent to the contact tank where it is dosed with chlorine. It may also now be UV treated but I'm not sure about that. I helped built the place in the late 1960s so the details might have changed a little in the past 50 odd years.

CAT also use a sand filtration system for their Welsh mountain water. They have now stopped people swimming in the reservoir, unfortunately, and removed the old hut next to the lake which was used as a sauna. It was popular amongst the MSC students!

Sand filtration relies on a Smutsdekker (spelling??) layer of bacteria in the top layers of the sand to remove other bacteria and pollutants while the depth of the sand removes any silt and fine particles. It is actually a bacterial treatment system. This particle removal is essential for any UV treatment to work as even tiny particles floating in the water can shield harmful bacteria from the UV light.

If you are bottling dirty water and leaving it in the sun it is best to filter the water if possible and it is essential that the bottle is agitated several times to ensure that the sunlight gets into all the nooks and crannies of any dirt particles in the water to kill off all bacteria.

[Default0ptions]

Quick and Dirty (no pun intended) is a canvas Millbank Bag followed by a good rolling boil. This will give you a reasonably clear water free from bacterial and viral contaminants.

Stream water depends on location. Any stream getting run off from agricultural or industrial or urban land will probably have unpleasant chemical contaminants.