I'm looking for folks with experience using a reverse osmosis system in a home with a deep well and on a septic system. The deep well is a typical
20-40 psi system. From what I've been able to determine, RO systems require a relatively high incoming water pressure and, even with a good water pressure (say 55-60 psi) a lot of water is bypassed to the drain.
Is there a potential problem using an RO system in this situation? Is there enough bypass water to cause problems with a septic system effluent field?
How about if I install a booster pump to push the water pressure to the RO unit to 65 psi?
if you have a sumersible pump you should be able to set the pressure up to 60 psi at the tank have someone who does well service in your area check it to make sure the pump is sized properly to deliver the additional pressure. they should be able to check it with just a standard service call fee scott
I run the effluent line into my toilet tank and shut off the inflow. That way it does double duty. I don't know if it will solve your septic overflow problem but it will help.-Jitney
A typical RO system can make about 30 gallons of water per day. If it does that, it also wastes another 30 gallons of water. However, if you don't use any filtered water, so the RO tank is full, you will waste the entire 60 gallons.
If you have an automatic shut-off valve installed, this will turn off the input water to the RO system when the RO tank is full. That stops any additional water waste. In that case you only waste as much water as you actually use, which is probably much less that 60 gallons/day. This will not only reduce load on the septic system, but also on the well pump.
I don't think even 60 gallons per day would be a problem for a properly sized septic system.But there is no reason you need to drain the RO system into the septic system. If you have a sump pump in your basement, drain the RO system into it.
I thought of using it for laundry too, but a chemist told me that the higher mineral content of the effluent makes it like hard water, with all of hard water's problems. The turds can't tell the difference, though. I also use it for dust control in my business, and in the pressure washer for cleaning mud off equipment.-Jitney
I haven't installed the system yet and I'm trying to determine what I'm up against, if anything. It's claimed to be a 100 gallon per day unit and it's not all that expensive. I plan to use the system only for drinking water and an ice maker.
I've done some reading on the web and, of course, there are some conflicting statements. For example, one site says that a minimum of 35 psi is required and that at lower pressures essentially no water is forced through the membrane and all of the water goes to the drain. They go on to say that the higher the input pressure, the better the ratio of pure water vs. bypass water going to the drain. Thus, on a deep well system they recommend a booster pump to get the input pressure above 60 psi.
There's also a gizmo that supposedly substantially reduces the water going to the drain called a permeate pump. These folks claim that some RO systems can drain 10 gallons to waste for each gallon of pure water produced. The claim is that a permeate pump will reduce the wasted water by up to 80% and will also extend the life of the RO membrane.
Some manufacturers claim that an RO membrane by itself will eliminate over
99% of bacteria and viruses while another manufacturer says that you must have an ultraviolet treatment filter to eliminate bacteria and viruses.
I have considered running the waste water somewhere other than the septic system. Probably a storm drain.
Oh, yes, and another thing. Some manufacturers claim that you shouldn't use a DI filter in a drinking water system. Another site claims that you can use a DI filter if you have a taste and odor filter downstream from the DI filter.
One site I visited even claimed that you shouldn't use a DI filter in a drinking water system because if you use the DI filter you essentially remove ALL if the impurities from the water and that will adversely affect the taste of the water. I thought RO was supposed to remove nearly all of the impurities (dissolved minerals) from the water. I realize that nothing will remove ALL of the impurities, even triple distillation. I'll have to admit, I worked in a lab once that had an RO system with DI filters afterward, followed by a UV treatment stage. I tasted the water once and it did taste off, kind of flat in my estimation.
I had a problem with my system not having enough pressure to activate the shut off when the tank was full and the discharge line ran continiously. (On a well with the pump shutoff set at 50 psi.) I obtained a permeate pump from
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and it solved the problem. It works by using the pressure from the discharge to increase pressure of the source water. The tank now pressurizes fully and the shutoff works properly.
My understanding is that a r/o system works better after a sodium exchange water softner. They reject sodium easier than calcium and you are less likely to get scaling of the membrane.
Some are concerned about bacteria with r/o and if your water is contaminated it will concentrate in the filters. The r/o will filter
95% of nearly everything on the ionic level (ie. sodium and chloride ions). I have a conductivity meter (measures in microsiemens) and have confirmed this % cleanup and better with r/o systems. Bacteria and viruses are larger than sodium ions and 95% are filtered out. Its the
5% remaining that you have to worry about. I personally feel that its an improvement on the water you start with and as long as you change your primary and post filters regularly and don't leave the water in the system sit for weeks without use you will be alright. Bacteria can grow in filter media if they get a good foothold. 15 years drinking r/o and three houses on a well and no problems. Your mileage may vary.
The waste water is "white water" vs gray or black water, I don't run my laundry, softner discharge or r/o reject into my septic. (softner discharge is also considered white water, laundry is gray) What you do with this water is another topic and can be restricted in some areas.
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