Reverse Osmosis, But First....

First an update. We are over 50% done with the OSB lining of the shop and installation of the fluorescent lighting. We will get a little done this coming weekend, as Saturday we are off to the Pueblo Chili Roasting Festival and Sunday there is a ACPOA Board meeting.



On to reverse osmosis water treatment project.

We have had our water tested every 6 months over the last 18 months as part of the BRM CUP requirements. Our water has come back well within the acceptable range on all reading except for sodium (salt) where is has been at the high end of the range. This along with the number of plastic drinking water bottles that pile up awaiting recycling has resulted in us looking at RO systems.

As we thought about the RO system, we focused on supplying water to the refrigerator for drinking and ice making. Other uses like washing, showering, etc. would not need a lower sodium feed.

So off I went as always looking at systems, how they worked and what would be needed to put one in.



As my research started something jumped out of the numbers right away and that was there efficiency rating, or how much of the water pumped into the system actually made it past the RO membrane and how much went down the drain. Household systems tend to be in the 5-15% range. This means that on a 15% efficient system, for every 15 gallons of filtered water 85 gallons went down the drain.

To understand this here is a simple explanation of a household RO system. There is a small pressure tank from which the filtered water is dispensed to the faucet, etc. When the system detects a drop in pressure beyond a certain preset limit from this tank a pump kicks in on the water supply side pushing water against the reverse osmosis filter. Water is essentially not compressible so not all of the water pumped against the RO filter makes it trough to replenish the pressure tank reserve, so it has to go somewhere and that somewhere is usually down the drain.

Now if you have access to unlimited cheap/free water this would probably not be a big thing, but when on a well it is, because water is not free or unlimited.

So armed with this, the search was on for a system that did not send the 85%-95% down the drain, but back into the supply circuit.

As chance would have it, I received my weekly email notification from Costco (we aren't members) on their specials. Listed was a "zero-waste" RO system. As I looked at how this worked, it appeared fairly simple in that instead of plumbing the waste side of the RO system into the drain, it put it back into the warm water supply line of a sink. I noticed in looking at other manufacturers of ZX systems (household size systems), they also used this builders components.

This was what we were looking for, a RO that didn't waste the water. But I still needed to check this out, and after looking at forum after forum of comments the biggest "con" found, was that the RO filter may need to be replaced sooner, but in the trade off between that and pumping (not pouring) water down the drain it was a easy choice.

If the system was to be installed in a base cabinet near the refrigerator the installation would be pretty straightforward, but as with most things this was not to be. Although there is a great cabinet next to the refrigerator, it was deemed by the LOML that this was part of her territory and the border would not be breached for this "thing".

It took a little bit to re-group, but the answer lay in the room behind the wall, on which the refrigerator was located...the laundry room. Even though this was not with in the "kitchen" boundaries it was still with in a sensitive area and annexing space was not something done lightly.

The only untouched/unclaimed space in the laundry room is located above the washer and dryer. This was the spot, so now what to do with it. Needed would be:

• Electrical
• Water supply
• Water return
• Access to the refrigerator water inlet

Obviously, this called for a cabinet, one that would hide the waterworks.

So, another cabinet is going to be build and hung above the washer and dryer. It will have a flip-up faux front of doors to provide access. Water lines will be run from the utility sink beside the W/D and the water will be delivered through a hole through the wall behind the washer to the back of the refrigerator. The unit will be plugged into the duplex washer outlet.

I don't want to jinx this by saying it is an elegant answer to the problem until it is done, and the results are known. Beyond not buying bottled water or having plastic bags full of them in the garage waiting for Derek to haul back to Gunnison for re-cycling, the flawless integration of the cabinet into the laundry room will be the measure of success.