uv light for water treatment

I don't know if this is really where this thread belongs. I am looking for alternative sources of potable water (other than municipal systems). My two options, rainwater catchment and use of natural water on the property wouldn't leave me with potable water without treatment. would a uv treatment system be a feasable option fo residential use?
http://www.waterhealth.com/water-solutions/technology.php

I would think there would be loads of options.

There is a book called something like "water storage" that is a real eye opener.

Also, it could be worthwhile to explore sand filtration.

What are you trying to filter out?  Minerals?  Organic gick?

filtering out particulates seems pretty easy with a sand or other filter but reliably filtering out bacteria and viruses involves expensive filters that need replacing regularly, at least from my understanding. I want a system that can turn the water off my roof or out of my creek into something I would feel good about giving to my precious little girl if necessary. on a short term basis I know it can be sanitized with bleach but I wouldn't want to do that very much! ickkk

I've read about the UV stuff about five years ago and my memory is that it seemed like the best of many options.  Until I read that book on water storage.  I can't remember details, but I do remember thinking that the stuff talked about in that book made a lot more sense and it seemed easier to implement.

what book was that?

link to "Water Storage"

The two biggest names in water harvesting are Art Ludwig and Brad Lancaster. Check out their books and websites.  Ludwig gained his excellent rep with his work on greywater (it's at his site).

Art Ludwig's site:  http://www.oasisdesign.net/

Brad Lancaster's site:  http://www.harvestingrainwater.com/

UV treatment has a pretty good reputation, but there are certain conditions that have to be met.  One is that it won't work on murky water, so you do have to filter it quite well first.  The second is that it can only treat small amounts of water at a time, usually as it passes the light.  This is not a real drawback, I don't think, but you can't just immerse a UV light into a 6,000-gallon cistern and have it purify it.

I have not investigated this thoroughly, but in these days of an unstable world, what happens to your water supply if the power goes out?  Do they have solar connections?

Like pellet stoves (clean, easy, stackable fuel), things that can ONLY be used with electricity always make me think there's a better way! 

Sue

SueinWA wrote:
I have not investigated this thoroughly, but in these days of an unstable world, what happens to your water supply if the power goes out?  Do they have solar connections?

Like pellet stoves (clean, easy, stackable fuel), things that can ONLY be used with electricity always make me think there's a better way!   

Sue

That is what gets me into this line of thinking. What wouldwe do if we couldn't just walkover and turn on the faucet. I have resisted a pellet stove and really want a real wood stove. Pellet stoves are nice until the stores or your stores, run out, then what?

There is said to be a shortage of sawdust, beginning last winter.  Here in the Olympia area, the price of stove pellets has jumped 28% (by the ton, 50 bags) from last year. Of course, last year, it was kind of hard to find any to buy, as they were being rationed.

Sue

last year when 1/2 the area was without power those bags of pellets were nowhere insight. of course the nearest generator for sale was 2.5 hours away from us in ft. smith and the grocery store shelves were wiped out because of loss of refridgeration coupled with the fact that any non cook convenience foods were snatched up. It was a good lesson for alot of people.

Maybe not a good enough lesson, though.  Shortly after the power was back on in most areas, many people tried to take their used generators back to Home Depot, Lowe's, etc.

Whenever there's a windstorm advisory, water and certain other items disappear from the shelves.  Don't people keep a supply of water at home all year?  If not, why not?  Suppose we had an 'unannounced' earthquake (the only kind I've known)? 

People as a group are pretty silly creatures. 

Bright note on that power outage, though.  I live near an IGA grocery store.  Once it was obvious that their power wasn't coming back on very soon, the store manager had his employees telling everyone in the store that they were selling all the packages of meat for $1 per package, and all the frozen goods were free.

Doesn't this make more sense than just locking the door and letting all the food rot?

Sue

shucks I wish they would have done that around here (maybe they did and I missed out) by the time we got out and about there wasn't a gas station or a grocery store open. The only place open...our farm and garden store....way to go! I did some of my christmas shopping following some poor guy around the store with a flashlight! All my roundbales were iced over I'm sure glad that I had a few square put back to feed in the barn.

I don't know anything about potable water treatment, but I know that in my backyard pond a biological filter does wonders to keep the water clear.  But I have never tried drinking from my pond ...

In my opinion/experience, the key to the bio filter is getting the water 1) aerated and 2) flowing through the roots of water plants, which act as host surfaces for bacteria, which do the cleaning.  You can of course use other material but in my experience, plant roots worked really well.  Plus the plant is nice to look at. 

In my case the plants are in pots, sitting on top of the filter.   They are just some kind of native water grass.

I have attached an older photo of the pond, taken in August when the high's are in the 80's.
This pond is for experimentation, not for beauty

So if you are using surface water you might think about somehow directing water through water plant roots.  This is easiest to do if the plants are in pots.

Leah,

If you get enough direct sunlight during the day you should check out solar water distillation. There are some free plans available on the internet and they are relatively cheap to run and build. Given enough sunlight, water, space and materials I think a unit could be built big enough for almost any needs.

Jeff

justhavinfun wrote:

If you get enough direct sunlight during the day you should check out solar water distillation. There are some free plans available on the internet and they are relatively cheap to run and build. Given enough sunlight, water, space and materials I think a unit could be built big enough for almost any needs.

Do you have a link or two?

paul wheaton wrote:
Do you have a link or two?

Paul,

Well it would appear that most of the plans available six months ago are no longer available, however the below links should provide enough info. for a do it yourself type to get started. Also do not overlook the fact that solar cookers often can be easily converted to solar distillers and solar pasteurizers.

Beyond solar I bet an ingenious person could work out how to use the heat from a rocket stove to distill water also, although at that point from my understanding solar distilled water would still be a better option; but if you have a rocket stove, time and some tubing etc. and none of the things to build or buy a solar distiller......

The basics of solar distillation:  http://www.ehow.com/how_2284283_solar-water-distiller.html

A working solar still made from 95% off the shelf materials no plans but enough info to easily follow their lead: http://www.thefarm.org/charities/i4at/surv/sstill.htm

Another working still, this link has a link to $15 plans for building a solar distiller although I think the author was not impressed with the detail. http://members.cox.net/ahicks51/osp/Technical_Data/solar_water/solar_water.html

The basics of solar pasteurization (solar pasteurization is more for relatively clean source water):
http://forest.mtu.edu/pcforestry/resources/studentprojects/cleanwater/Solar-Box.htm

Sells a do it yourself kit for solar distillation based on the above mentioned plans (plans included) as well as a premade unit: http://www.solaqua.com/index.html

One mans experiment with solar distillation (much can be inferred from this page) : http://www.thesietch.org/projects/distiller/index.htm

I am thinking about purchasing this for my small scale needs when it becomes available( I store rainwater for my cactus as the local water Ph is too high for them) this site has a lot of interesting items for using solar energy in the home: http://home.att.net/~cleardomesolar/solarpurewaterstill.html

I think given enough time and exposure to sun one of these systems could be built large enough to cover almost any water needs. Designed to produce more water than needed daily and coupled with a storage capability and perhaps basic filtering if needed as well as some form of simple automation for water delivery (gravity would work fine) one of these systems would only need basic maintenance and periodic cleaning.


Jeff

I understand!

In fact, the poor man's solution is pretty smart!

these are all some great links. thanks guys! the  http://oasisdesign.net/ site has alot of really good info about getting potable water.

the pond water post reminded me that UV water 'sterilizers' are commercially available for use with fish tanks.

http://saltaquarium.about.com/od/filtersetupsother/a/aauvsterilizati.htm

If UV kills bacteria in fish water, there's no reason that it won't similarly kill bacteria in potable water.  However, the flow rate / exposure time needs to be carefully monitored I'm told.