RAinwater Collection for Domestic use?
user-153171
| Posted in General Discussion on
Anyone got info to filter rainwater from Duroid roof for domestic use? Not needed for potable source.
Replies
Always liked the idea of grey water for a toilet, garden etc. Rented a cottage (seasonal) that had a rain barrel for two sides of a gambrel structure and used a sump pump about 8" off the bottom of a 55g.plastic olive barrel to pump into a cistern in attic that had an over flow pipe to grade. in a heavy rain I imagine the pump would run a lot or it could use a float for high water cut-out, wasnt there in rain. Filtered to 5 micron it would do a lot given a big enough cistern and rain one could do well .
That was a very primitive set-up but quite servicable, with pretty fittings, a municipal back-up for dry spells and the high water cut-out you could use a smaller tank in attic (given that the pump will develop enough head pressure).
Will be watching for tips for own use as soon as residence is habitable-- I get to play.
thom
You're basically talking about a cistern. A few million homes in rural areas of the US have them.
If you don't get enough info on "cisterns" here in Hawaii they call it catchment water. Fairly common, and does not seem very complicated. Here they run downspouts to what looks like an above ground swimming pool with a cover, and pump through a filter to the house. All you need is yard space and clean gutters I guess.
Dan
Where I'm most familiar with them, rural Kentucky, they're either underground or under a porch or such. Usually poured or precast concrete in the past, though I suppose plastic is gaining favor. I've seen them made out of creek stone."Filtering" may include a coarse screen to keep out leaves and such, but primarily consists of letting the gunk settle to the bottom (giving the water a rich tannic taste :) ). Every few years (or decades) the tank is emptied and cleaned.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
Garth,
You'll need a couple different kinds of filters.
Your first filter is going to be something to try to keep sediment, mosquitos, etc out of your water.
You'll then need to filter the water once again, as it enters your system.
For the first filter you can go with a simple sand filter. The filter consists of a box that is partially filled with gravel, then partially filled with sand.
You'll have to change the gravel and sand on occasion. If everything from there on through your system is sealed, you should at least not have a problem with mosquito larvae.
But some sediment will get through. And you'll have to concern yourself with algae and water stagnation as well.
For water stagnation, simply put in an aquarium air pump. It doesn't take much...
For the algae and other contaminants like girardia, you'll need to clorinate. Using regular old clorox household bleach, you would try to keep the water clorinated at a rate of 1 oz bleach for 300 to 400 gallons. (My water tank was destroyed when a tree fell on it, and I haven't been able to afford another one yet. But when I was using it, I cheated and used that little plastic cup that comes with a bottle of pepto-bismol for the amount of bleach for 350 gallons of water.)
Use a double filter in the house, before the inside pump. In one filter housing use a string filter. In the other, use activated charcoal. String first, charcoal second.
Do all the above, and the water is safe for showering at least. (You do get water in your mouth, and your mucous membranes like your eyes when you shower.) And if you put it through one more step... A "PŪR Plus" filter, (Available in a one or two gallon container that holds the filter, or as a faucet attachment.), the water will be suitable for drinking.
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A side note, I'll be setting up a rainwater collection system sometime in the next couple of years myself. I intend on compiling a pre-filter using large fittings/containers, and several layers of "register filter" material. It is just like scotchbrite pads, but it doesn't have chemicals on it. It comes in pieces sized to fit floor registers for heating.
The destination is not the point. The completion is not the point. Enjoy today. If you can't enjoy today, then what is the point ?
Don't know your location but is freezing tanks going to be a factor?
Here in central TX, we use rainwater for domestic water supply as a common approach to getting superior water to what a well would supply. Our rainwater system gives us water that is better than any municipal water supply. Clorine is not needed or desired.
Mesh is installed in gutters and again at the collection boxes. These are cleaned once a year. In front of the tank, another filter box contains perforated pipe that is wrapped with polyester batting. This keeps the fines out of the tank. The tank will not need to be drained and cleaned ever. This filter is cleaned as needed, for us, about twice a year. Some people clean it after each rain. From there the water is pumped back to the house where it is supplied unfiltered to some hosebibs.
Once in the house, the water is run through a "big blue" 4"x10" filter housing with a 5 micron filter to clean it. Next, it runs through a 4"x10" granulated active carbon filter to remove odors and further polish it. The water is now clear and runs through an ultra-violet light for sterilization. It is important that the water be very clear so the UV can fully penetrate it and kill all the bacteria. The UV needs a monitor to insure that UV penetration is adequate. A solenoid valve can be attached to the water supply to close off the flow if sterilization is not adequate as measured by the UV monitor. This can happen if the power goes out, the bulb gets old, or the water is not clear enough. The water can appear clear and still have enough turbidity or color to refract the light so that some of the bacteria escapes sterilization. We have this monitor set-up as recommended by the EPA but none of our neighbors do. After sterilization the water is safe and tasty to drink.
We go further however by running it through another treatment prior to drinking or making ice with it. This last system consists of another 5 micron filter, another carbon filter, a reverse osmosis filter, and another carbon filter. No bottled water can match the quality of our water. This water has no fluoride, so you should use a fluoride toothpaste. There are thousands of rainwater systems in central TX. I would rather treat the water in my tank than trust the municipal water supply to treat the water from a lake.
These sysyems are quite expensive when done right. My tank is plastered concrete and has a 24,000 gallon capacity. The entire setup with gutters, piping, tank, and pump and filters came in at 14,000 dollars and maintainace runs 200 dollars a year for filters and UV replacements. It is more if someone else maintains it for you.
Now THAT's the system I should have had. My cistern was simply a walled-off area in my basement to which a roof downspout emptied. A pump and a pressure tank fed this water to the shower, bathroom sink, washing machine and kitchen sink.
The only filter was immediately downstream of the pressure tank.
Showered, brushed our teeth, washed our dishes and clothes with that water. No cover on the cistern.
I imagine the missing pane on the window next to the cistern let all sorts of critters in. Well, I know it did, 'cause one summer the water tasted particularly bad ...
A stray cat had drowned in there.
I pumped out the cistern and connected my entire water system to the well.
Allen
What percent of your water needs does that supply?
All our needs and enough to water the garden.