Can rain water be safely drank ?

Question

My friend has been drinking rain water from a cistern . He say's since they did 100 years ago, why not now ? I have tried to explain the rain cycle to him, but he feels that there is no threat. Give me something solid to educate either him or I .

Answer 1

If there were no pollution, the rain would still be acidic. Natural rainfall has a pH of around 6.0. This is because of the effect of Carbon dioxide in the air which combines with water to form carbonic acid. The effect of this is however negligible, as it is neutralised in the soil by alkaline material like limestone. However the other emissions cause the pH of the rain water to drop below 5.5 and at this level it is considered to be acid rain. The soil cannot now neutralise the acidity of the rain water. In some places the acidification is so severe that the pH drops to around 4.0. Rare cases have been reported of acid rain having pH of around 2 - 2.5.

Answer 2

from a cistern? isnt that a kind of well?

which means the rainwater has been filtered though the ground possibly...

Possible contaminants could be pollution, animal/bird droppings, or bacteria. The water should definitely be filtered and boiled for at least 20 minutes before drinking.

The best would be to have it tested in a lab.

Someone suggested adding 3 tablespoons of bleach/ gallon. That would definitely sterilize it, but it will also make it taste strongly of bleach, and may be far too much to be safe. Better to use water purification tablets ( sold to backpackers).

Answer 3

I live in Australia and at the moment, we are facing a crisis in our cities in regards to the amount of drinking water available to us. There's awhole lot of hoohaa going on in the government about building huge plants called "desalinisators" which are designed to clean the salt from seawater to provide us with the much-needed aqua vitae.

For mine, there's a much simpler solution which is being suggested by The Greens and that's to subsidise the supply of rainwater tanks to every home in suburbia. It's a damn sight cheaper than the vast expense of desalinisation and much more energy and resource efficient.

Just about every person who lives outside of a town or city in my country has a bunch of rainwater tanks installed to catch what rain falls onto their roofs. This is pretty much the only way that we can live in country Australia - apart from pumping water from a local creek or river of course, but these days such resources are often polluted by runoff from agricultural practices. Not many people have ever become ill from such a lifestyle and harvesting technique.

There's also NO NEED to add anything to counter the effects of bird guano in a supply - think of the amounts we're talking about! Bird droppings on a roof would come to several grams at most - the amount of water in a standard rain tank measures in the thousands of litres! Therefore, if any toxins were to exist, they'd be naturally diluted in such a large volume rendering the water safe!

Also, I don't think that we've managed to pollute the global water cycle to an extent where every drop is harmful. At least, not yet! Of course you'd have to look at where you were going to be establishing a tank - I agree that suburban LA or NY wouldn't be a terribly good place to put one without some kind of very good charcoal filtration system!!!

Finally, a little ode to a magnificent natural water source which I discovered in a remote rainforest many years ago:

"Spring water
sprung forth
ahh, the earth

Pay two dollars
to visit this
in a shop"


Love and Light


Jarrah

Answer 4

Generally, rain has a pH slightly under 6. This is because atmospheric carbon dioxide dissolves in the droplet to form minute quantities of carbonic acid, which then partially dissociates, lowering the pH. In some desert areas, airborne dust contains enough calcium carbonate to counter the natural acidity of precipitation, and rainfall can be neutral or even alkaline. Rain below pH 5.6 is considered acid rain.

perhaps that would help.....

Answer 5

it depends on where the rain is. in LA or NY i wouldnt drink rain water if you payed me. but in the country the rain water ought to be better than any water you can find on the ground...except maybe out of a filter.

Answer 6

There are bird dropping's on the roof sometimes and he needs to use a little Clorox ,about 3 tablespoons per gallon.