Purify water with sunlight using clear plastic (PET) water bottles

#1
This entry at Modern Survival Blog details precisely how to do it using clear plastic water bottles less than 2 liters.

Link:
How to Purify Water with Sunlight

The method only kills biological contaminants, so use a water source that doesn't have chemical contaminants.

Excerpt: (don't skip reading the blog entry ....lots more info there!)

---Know your water source (as best you can)… if you believe it to be chemically toxic, don’t use it.
---Fill the bottle with water. If the water is very cloudy, it must be filtered by first pouring through a cloth or such material to capture sediment.
---Lay the bottle down in the sun. Do not stand them up. Ideally the bottles would by placed so that they face the the sun at a similar angle, to maximize the UV-A penetration.
---Even better… lie the bottles on a reflective surface to increase the UV-A exposure using direct and reflected sunlight. This is not necessary, however it would shorten the required time and ensure optimum UV-A exposure.
---If the sky is partly cloudy with only a few clouds, then 6 hours sunlight exposure will be enough. If the sky is half filled with clouds, or more, then 2 days will be required.

Note that the outdoor temperature does not matter, so long as the UV-A sunlight exposure has been 6 hours.
 
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Vader

My other car is a Death Star
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#3
This entry at Modern Survival Blog details precisely how to do it using clear plastic water bottles less than 2 liters.

Link:
How to Purify Water with Sunlight

The method only kills biological contaminants, so use a water source that doesn't have chemical contaminants.

Excerpt: (don't skip reading the blog entry ....lots more info there!)

---Know your water source (as best you can)… if you believe it to be chemically toxic, don’t use it.
---Fill the bottle with water. If the water is very cloudy, it must be filtered by first pouring through a cloth or such material to capture sediment.
---Lay the bottle down in the sun. Do not stand them up. Ideally the bottles would by placed so that they face the the sun at a similar angle, to maximize the UV-A penetration.
---Even better… lie the bottles on a reflective surface to increase the UV-A exposure using direct and reflected sunlight. This is not necessary, however it would shorten the required time and ensure optimum UV-A exposure.
---If the sky is partly cloudy with only a few clouds, then 6 hours sunlight exposure will be enough. If the sky is half filled with clouds, or more, then 2 days will be required.

Note that the outdoor temperature does not matter, so long as the UV-A sunlight exposure has been 6 hours.
Allye, do you know of what you would need to test the water for chemicals? I would imagine that due to ag in an area that streams have the likelihood of being contaminated.
 
#4
Allye, do you know of what you would need to test the water for chemicals? I would imagine that due to ag in an area that streams have the likelihood of being contaminated.
Woundn't have to test around here! We're heavily ag. I wouldn't even use water from a groundwater well except for a short-term survival situation. Would be the same in an industrial area, in the mountains where there's strip mining etc. I carry a Sawyer mini-filter and purification tablets in my GHB and they don't remove chemicals either. If there's a source of running surface water like a creek, that would be a better choice than water from a pond, slough or a stagnant ditch. But even then in certain areas, there's going to be contamination. September here is when crop dusters spray cotton defoliant ...nasty, nasty stuff. That's also our driest time of the year, so if I'm ever forced to hoof it for survival during defoliant spraying, I'll purify the water as best I can and drink it. Hope never to need to at any time though!

For short-term survival in an area with plenty of sunlight, it's a good method if you have no other means of purification.
 
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