*Water Filtration for the Retreat*
By: GrayFox
8-25-02

I recently began thinking about a large-scale water filtration system for a retreat and how many different options are available. If TSHTF and you had to relocate and start over digging a well would be a job that I would not want to tackle and may not even be a feasible option in some cases. This article will cover Reverse Osmosis and Ultraviolet Sterilization. This is just a basic overview covering the pros and cons, price, and effectiveness. Setting up these systems will have to be a separate article in itself.

Reverse Osmosis units use a membrane, or series of membranes to remove minerals, bacteria, heavy metals, carcinogens, pesticides, etc. from the water. What you end up with is practically 100% pure water. This is not really what you want for drinking because all the minerals that are normally absorbed into your body are not available. Prefilters and membranes last from six months to five years depending on the model. Another issue that could pose a problem is that most units require a certain amount of water pressure to operate effectively. Most need 65 PSI to operate at maximum efficiency. R/O units also waste water. For every gallon of usable water, 3 to 4 gallons go down the drain. If you catch the water you could use to water a garden or livestock. One good thing about R/O units is that they require no power at all if you can get the required water pressure. This could be accomplished by having a large enough water tank at a higher level than the R/O unit or by running a water line from a stream downhill to achieve the required pressure. R/O units can provide from 24 gallons per day to 2,000 GPD. Prices start at $80.00 and go into the $1000ís for a high output system. If you consider using these shop around. These units are used to provide soft water for aquariums and are available in many different models. Online pet retailers are a good source for these units as well as home improvement stores and industrial suppliers.

Ultraviolet Sterilizers use ultraviolet light to kill algae, protozoa, bacteria, and other nasties found in water. They do not remove chemicals, pollutants, minerals, or metals. Prices start around $75.00 but to get a unit that would handle a group youíre looking at $125 to $350.00. The main problem with this system is the amount of power needed, but they could be set up on your solar grid and only turned on while in use. You can find systems that run on 12volt DC but Iíve only seen them in the $300.00 range. UV sterilizers also have maximum flow rates so the flow may have to be slowed for the sterilizers to work effectively. If your sterilizer was rated at 1000 GPH max. I would recommend having a flow rate of no more than 750 GPH to ensure proper sterilization. Installing a gauge that shows the gallons per hour would help monitor flow rates. The benefits of this system are that none of the minerals are removed from the water and the water does not have to be at a high pressure to operate. Again these are also available from pet retailers, industrial suppliers and companies that sell water softeners and purifiers.

Either of these systems could provide enough water to sustain a retreat housing several families. I have priced the equipment necessary to provide 100 gallons of water per day using reverse osmosis and it would cost me around $250.00 USD. This included 50í of PVC water line and fittings but not a tank which would add another $250 easy. The UV system would cost around $200.00 for the same output but doesnít include a way of powering it if the grid goes down. Add about $150.00 for enough to handle more than 5 people on either system. These two systems are kind of give and take both having good and bad points but both would provide dependable, easy to maintain methods of large scale water filtration.
GrayFox



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