Hi everybody! I didn't write in this post for a long period, but I am still interested in this subject. Thank you for your help! From now on I'm going to see nearly every day if you will add your ideas here, even if I didn't write a message. If you are interested in this you could write here or send me a message. Thank you everybody!
Thank you for you answer, Andrew.
I had already read an article about admitting failure from the EWB Canada website.
EWB Canada's failure is a bad news, but I have a different opinion about what is the failure: if you failed helping someone it is a failure, and about this they didn't fail enough, but for me the real failure is the fact that someone needs their help, and if you help someone and you don't succeed in doing this you don't do something useful, but you don't do an evil thing.
I read the "next message" about boiling water, I don't want to say that there are methods that could replace boiling water, but that there are methods that could work better together, for example, about boiling water, I don't dare even say that boiled water is safe, because it can kill some bacteria and viruses, but not every bacteria and viruses, and besides it doesn't remove chemicals or other substances in the water.
I said about the SODIS method that the WHO and its section WSH wrote about it, and about many other methods to get drinking water: Managing water in the home: accelerated health gains from improved water supply - Heat and UV radiation.
So, of course I don't say that something is safe, because I don't have a good knowledge of this, but if the WHO and the WSH say that those methods are at least good and useful I think that it is a good thing.
Location: Salt Lake Valley, Utah, hardiness zone 6b/7a
Yes, I agree that doing something is sometimes better than doing nothing at all.
There were 9 posts in the thread. I hope you were able to review them. Not all of them are noteworthy, but there are good references in some of them. The one that struck me the most was the one that said, if it is a choice between plentiful dirty water and limited treated water, plentiful water is more important to good health than clean water, statistically.
From what I have read, SODIS is a viable option in many circumstances, but you must start with clear water, you must have bottles made of the right material, the bottles must be properly sterilized between uses, among other things, so, like many other methods, it is not idiot proof.
If I had to prioritize: 1) access to fresh water (even if it is thick as mud), 2) treat for turbidity, 3) treat for remaining pathogens, 4) treat for remaining toxins
That does not address distribution and storage.
In researching the subject for a reply to the thread, one writer mentioned that protecting water quality can be more effective than water treatment. I remember watching a documentary on eliminating schistosomiasis in a Caribbean island by creating water storage upstream of areas contaminated with schistosomiasis carrying snails and piping the water to the villages for bathing, washing, drinking and cooking. I never saw or read a follow-up of that project to learn if it had long-term viability.
You may also be interested in reviewing plans and theory behind a novel Solar Distiller design here:
Thank you for your answer.
The SODIS method could have drawbacks, for example the leaching of bottle material.
This is a problem, but there are 2 kinds of problem:
1 a device has its own drawbacks for its nature ( for example the plastic material of the SODIS bottle, it could be the PET ) ( For this problem you have to look for informations from experts )
2 a device has not drawbacks for its nature but it could be dangerous if you use it in a bad way.
You are right when you say that something could be a risk, for example the post you wrote about, that says that it could be possible to get drinking water without boiling it.
For every method you have to see if there are the two problems.
I am looking for the second kind of devices, those that haven't got drawbacks for their nature.
About the SODIS method, I hope that this could be useful, but it has got the first problem, so you have to read reliable documents, for example WHO and WSH research: I think that this problem is without a definite solution, but maybe there is a hope if WSH says that it is a good method, it is a discussion still without a solution, but if in that WSH document ( maybe a bit old, you have to see if their researches still confirm it ) it is still considered a good method, despite the leaching of bottle material, there is a little hope.
The second kind of devices is a very good thing: the solar still you wrote about, and artificial UV rays that could be a danger if used in a bad way, but there are ways of protecting from them: these devices have the second kind of problem, that can be solved in a definite way.
I like very much this second kind of devices, and I am looking for them, however I am interested also in the first problem about the SODIS.
I would like to challenge the idea that water sitting in cisterns becomes stagnant and unpleasant to drink.
My experience in Australia is completely different.
I store 2000,000L of rainwater in single tank and I use that water only as a back up. Sometimes it sits 3-4 years before its used and its always ok.
Its my guess there are problems with substances getting into the stored water you speak of.
Now if you store water in small tanks, 1000L with little or no airspace at the surface of the water, that may be the problem.
Tanks in Australia usually have a air space of at least 300mm above the water surface, and this may help with oxygen supplies being absorbed into the water to prevent stagnation.
Also you can draw water from the top or he bottom of the tank, that can make a difference.
John Daley Bendigo, Australia
The Enemy of progress is the hope of a perfect plan