Dan,

The attached article describes how the folks in Bermuda have collected and cleaned water for 100's of years. Might be a good starting point for some further research. Bermuda Cottages

BTW, that's one place in which I'd love to bug in, er, out, whatever. I've been lucky to have spent a lot of time there, a wonderful place with friendly people and beautiful vistas.

Interesting future thread, how do you cope if you're on vacation and disaster strikes?

A bit expensive, but this might be nice to use for a vessel to hold a filter. http://morebeer.com/view_product/8419/102211

Andy, Thanks, I'll read about the Bermuda cottages today.

While there's no easy way that I can think of to make a continual supply of activated carbon or activated charcoal in a long term emergency, charcoal by itself is still a chemical "filter". Though charcoal won't do as good a job as its activated self, I've read an article or two that stated using between four to ten times the amount of un-activated charcoal in comparison to activated charcoal will do a very good job. It's all about available surface area, and that's the magic of activated carbon/charcoal.

Also, you'll want to create as much surface area as possible to run the water through, so break down the large chunks of charcoal into smaller and smaller and smaller pieces.

So, if you're going to boil your water supply using wood, you may as well collect or make some charcoal while you're at it to use as a filter. It's not going to hurt.

Also, don't burn chemically treated woods...

Additionally, distilling the water before filtering through (activated) charcoal is an excellent purification strategy. Distillation removes everything except for a few volatile organic compounds (VOCs) that evaporate at a lower temperature than the water. Carbon (charcoal) filtration removes all of these VOCs very effectively.

Using the fire to do the distillation, then using the charcoal from the fire to do the carbon filtration not only seems like a very effective purification means, but it seems almost self sufficient as long as you can find wood for a fire.

If collecting rainfall is viable for you, just go ahead and collect some, then have it tested. I think you'll be surprised at what you DON'T find. Do this first, before you go crazy with the purification systems.

From "Harvesting, Storing, and Treating Rainwater for Domestic Indoor Use" from the Texas Commission on Environmental Quality
http://rainwaterharvesting.tamu.edu/drinking/gi-366_2021994.pdf

"The water in a raindrop is one of the cleanest sources of water available. Rainwater can absorb gases such as carbon dioxide, oxygen, nitrogen dioxide, and sulfur dioxide from the atmosphere. It can also capture soot and other microscopic particulates as it falls through the sky. Nevertheless, rainwater is almost 100% pure water before it reaches the ground."

I see you are in NYC. I read a clever way to keep birds from perching on the peak of your roof: screw a sturdy eye-bolt into each end of your roof peak, then stretch some stainless steel wire or strong fishing line between them. That's it.

Sue

What I am considering doing is using a cistern type collection system. In my area, most of the rain falls in the winter and early spring. Then we go 6 to 8 months with unpredictable amounts of rain. So, old timers in this area have done for many years, is have good gutters installed on their houses and outbuildings. Then have the water routed to go into a tank of some kind. I am buying a tank of poly 3,000 gallon capacity to be my above ground cistern. The water will be filtered in a filter similar in some ways to what you describe. If the first tank is a success I will add three more for a total capacity of 12,000 gallons to get us through the dry months. I want to make certain to have plenty of water for our yard, garden and orchard. If power goes in a severe problem we would have lots of soft potable water. My main concern for immediate use is for irrigating our food growing plants.

Wildman, Good luck rethinking your water gathering. If you find any food safe garbage size bags send me a PM. I've been searching for a supply of nonpoisonous garbage size bags for a while now, with no luck.

Intro to distilation
http://lorien.ncl.ac.uk/ming/distil/distil0.htm

How it is done on submarines
http://www.fleetsubmarine.com/fresh_water.html

Solar Stills
http://www.txses.org/epsea/stills.html
http://www.thefarm.org/charities/i4at/surv/sstill.htm
http://www.rotarnet.com.au/users/9/9520/SolarWater/swp.html
http://www.davesplanet.net/solarstill/

If you would like them I have several links to building stills. These are primarily for alcohol but can work the same to purify water.

In New Zealand many properties take their water supply from their own tank, which is filled by rainwater from the roof. No treatment is done, nor is it necessary. A simple diverter discards the first few minutes of rainfall (i.e. until the roof is "clean") and a grating deflects leaves and other debris.

Tank sizing at the beginning is very important, but if you don't get enough rain you can pay for a water tanker to show up (bit expensive though).

A