Drinking RO/DI?
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EricSIny
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fishgate
Active member
I looked and could not find any definitive source to confirm the bacteria theory. It sounds like it could be valid, but systems (that I could find) that are designed for human consumption (include the faucet and storage tank) do not have any extra parts like a UV filter. The only thing I could find that addresses the bacteria issue said simply let the first few cups run out to flush the system.
I'd say any filter is capable of becoming a breeding ground for bacteria including your frig filters.
Personally I use this for the coffee maker and am not going to stop.
I'd say any filter is capable of becoming a breeding ground for bacteria including your frig filters.
Personally I use this for the coffee maker and am not going to stop.
Our systems at work certainly employ UV.
I've given the reference in many other similar threads, and I'll copy one of my earlier posts here:
The concern with drinking post RO water is potential bacterial contamination since there is no disinfectant present. Bacteria can easily grow in RO only water as it has plenty of available nutrients. That is why many RO systems for human use incorporate a UV to kill bacteria.
Bacterial colonization of domestic reverse-osmosis water filtration units. Payment P Centre de recherche en virologie, Institut Armand-Frappier, Universite du Quebec, Canada Canadian journal of microbiology (1989), 35(11), 1065-7.
Abstract
We have analyzed the bacterial content of water from the reservoirs of 300 reverse-osmosis units installed in households. The heterotrophic plate counts on R2A medium (20 and 35 degrees C) ranged from 0 to 10(7) colony forming units per millilitre (cfu/mL). Most reservoirs contained water with bacterial counts between 10(4) and 10(5) cfu/mL. The bacteria identified were Pseudomonas (not aeruginosa), Alcaligenes or Moraxella, Acinetobacter, Flavobacterium, and Chromobacterium. This report emphasizes the importance of bacterial colonization by heterotrophic bacteria in water reservoirs from domestic reverse-osmosis units.
From the FDA:
http://www.fda.gov/ICECI/Inspections/InspectionGuides/InspectionTechnicalGuides/ucm072913.htm
Researchers at the Center for Disease Control (CDC) conducted extensive investigations on the bacterial contamination of RO systems used in producing purified water for dialysis (15). They reported: 1. certain naturally occurring Gram- negative bacteria can multiply in relatively pure RO water; 2. thorough periodic disinfection of the entire RO system is essential in producing water with acceptable bacterial counts; 3. stagnant water in pipes down stream of the membrane is the major source of bacteria and endotoxin in the product water; and 4. the efficiency of a membrane in rejecting bacteria is better in continuous operation than in intermittent use.
and
Technical Requirements of a RO System
Several basic technical requirements of a RO system are:
Feed water should be adjusted to proper pH and be prefiltered. The amount of TDS and suspended materials in the feed water after prefiltration should be controlled within the designed limits.
Feed water and product water should be monitored for microbiological quality. The system should be disinfected when microbiological quality levels are exceeded.
All system components should be mechanically cleaned before disinfecting. Appropriate tests should be performed to assure that chemicals used in disinfection are completely removed from the system.
The use of filters or ion-exchangers down stream of RO modules should be avoided.
The RO system should be designed for continuous flow without traps, dead ends and pipe sections which may collect stagnant water.
The chemical and microbial quality of water should be tested at predetermined intervals during a production cycle. In-line conductivity probes should be installed at key points for continuous monitoring of water quality.
The equipment should be qualified and the RO system should be validated periodically, as well as operated and maintained according to manufacturer's instructions so that it can consistently produce water with acceptable quality.
disc1
-RT * ln(k)
Ever done a total plate count on tap water? Not the water report numbers, but really plate out what is actually coming from the pipes in your house. That can be scary.
I gotta agree. While most of the time you'd be safe, you could definitely get into a situation where you had some real bacterial contamination issues and you wouldn't know until after you got very sick.
It's like eating rare beef. It works out for you 999 times and then one day.... BAM you find yourself in the hospital with E coli O157.
Many people asked this question focus on the minerals, but that's really no issue if you eat other normal foods and beverages. The difference in minerals between between fairly pure municipal water supplies or bottled water (with TDS in the 5-15 ppm range) and totally pure water is very small and may have little to no minerals of benefit.
But bacteria are still a huge issue. Different bacterial diseases are the 4th (respiratory), 8th (diarrheal)and 10th (sepsis) most prevalent causes of death wordwide.
mtcoins123
Far From Average
sometimes i am amazed at the wealth of knowledge here
sometimes i am amazed at the wealth of knowledge here
So i have a DUMB question! i have exstensive experience in underground water and sewer pipe installation. whenever we would complete a new system we were required to pass a "water test" before allowing the new part to integrate with the existing part. well some times when we had a difficult time passing the "bug test" usually on low chlorine systems, we would just wait a couple weeks. the idea was that the pipe would build a slime coating of "bacteria" or something that requires no light, and it has always confused me a little if your increasing the bacteria in the pipe how does that help to pass a bug culture? and all without any light in the pipe..
as a side note a great deal of the water pipe that is 20 plus years old is constructed of asbestos and this slime layer is the only thing between us and asbestos contamination if the pipe gets cur or repaired or damaged theres a sudden spike in asbestos particals for several weeks until the "slime coating" comes back we would quarentine the part of the system we repaired until this happened.
isnt all this bacteria concern really about the type of bacteria (dead animal in the supply or something like that) as a good deal of the "bugs" in our water are somewht necesary? (sans chlorine of course)
sometimes i am amazed at the wealth of knowledge here
So i have a DUMB question! i have exstensive experience in underground water and sewer pipe installation. whenever we would complete a new system we were required to pass a "water test" before allowing the new part to integrate with the existing part. well some times when we had a difficult time passing the "bug test" usually on low chlorine systems, we would just wait a couple weeks. the idea was that the pipe would build a slime coating of "bacteria" or something that requires no light, and it has always confused me a little if your increasing the bacteria in the pipe how does that help to pass a bug culture? and all without any light in the pipe..
as a side note a great deal of the water pipe that is 20 plus years old is constructed of asbestos and this slime layer is the only thing between us and asbestos contamination if the pipe gets cur or repaired or damaged theres a sudden spike in asbestos particals for several weeks until the "slime coating" comes back we would quarentine the part of the system we repaired until this happened.
isnt all this bacteria concern really about the type of bacteria (dead animal in the supply or something like that) as a good deal of the "bugs" in our water are somewht necesary? (sans chlorine of course)
The concern with bacteria are certainly very much related to the types present, but I don't think that municipal water supplies are trying to keep any in the water they supply to customers. The ozone, chlorine and longer-lasting chloramine are intended to kill nearly all bacteria. They focus on testing for a few types (like E.coli), but wouldn't want any that I know of.
fishgate
Active member
The water (if city water) starts out chlorinated and (relatively) clean. Then you run it through the RO/DI and remove more stuff. So the only issue is bacteria that may be living in the RO/DI filters. Since the first one gets chlorinated water from the source (the carbon and floss) I think we can discount that one. So I assume the problem is with the Membrane, downstream and DI filters. If the first cup or two of water that comes out is discarded, then it seems like the rest would be ok. Much would depend on how long you let your system sit without using it. Mine never goes more than 2-3 days without running for 4-6 hours at least.
Around here lots of folks are on well water (we are not) and I have never once heard of anyone having any water safety issues of any type.
btw: I totally 100% discount the FDA and any other governmental source as if the report didn't happen. It means less than nothing to me.
Around here lots of folks are on well water (we are not) and I have never once heard of anyone having any water safety issues of any type.
btw: I totally 100% discount the FDA and any other governmental source as if the report didn't happen. It means less than nothing to me.
disc1
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disc1
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So you've never heard of something called Cholera?
I can assure you that wells do indeed get contaminated sometimes. Just because no one you know has had it happen doesn't mean that it doesn't ever happen to anyone. That is some pretty ignorant logic.
disc1
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I don't see what my avatar has to do with that?
It's really not a matter of political opinion. I can plate the water out myself and count the colonies. I have done that. Not from a RODI, yet, but certainly I have done that a number of times with tap water. It's not opinion, it's science and opinion has no place in it. You measure a bunch of RODI systems and the bugs are either there or they aren't. Your opinion won't change that at all.
It's really not a matter of political opinion. I can plate the water out myself and count the colonies. I have done that. Not from a RODI, yet, but certainly I have done that a number of times with tap water. It's not opinion, it's science and opinion has no place in it. You measure a bunch of RODI systems and the bugs are either there or they aren't. Your opinion won't change that at all.
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Randy - I admit to having skimmed the posts a little, because more often than not, the details on things like this are a little over my head.
Is the bacteria issue more or a storage issue (nothing to prevent bacteria growth when the water is stored), or is it that the water coming through the ro/di can actually be "dosed" with bacteria that is growing in the filters/membrane?
I use my waste water for coffee, stored in a water dispenser. Should I be concerned? Is it possible the "heating" and chilling of the water would be enough to kill off anything it might contains (i know that is a broad question... and you can't give a specific answer, just wondering if there is a majority/minority type answer)...
Is the bacteria issue more or a storage issue (nothing to prevent bacteria growth when the water is stored), or is it that the water coming through the ro/di can actually be "dosed" with bacteria that is growing in the filters/membrane?
I use my waste water for coffee, stored in a water dispenser. Should I be concerned? Is it possible the "heating" and chilling of the water would be enough to kill off anything it might contains (i know that is a broad question... and you can't give a specific answer, just wondering if there is a majority/minority type answer)...
Why would it seem that way? A bacterial colony living on the RO membrane or just down stream of it can easily be releasing cells into the water. That is the concern, and is what was demonstrated by measurement in the links I gave.
FWIW, I not sure why you'd discount a health warning from the FDA, especially with no data suggesting they are wrong, but to each his own. :worried:
The concern is that bacteria can grow in the system anywhere downstream of where the chlorine/chloramine is removed (in the initial carbon filter). Bacteria cannot get through an intact RO membrane, but the filters we add and the housings we use and even the DI resin itself are not necessarily sterile going in, so bacteria can thrive there, especially between the RO membrane and the DI resin.
The waste water is actually upstream of the RO and so bacteria may come in with the tap water at times when disinfection is inadequate (if ever) and then reside on the upstream side the the RO membrane and on the downstream side of the carbon block filter. So waste water may be worse than RO product water.
I expect the chances of a pathogenic bacteria being in large quantities in your RO is low, but it would be enough for me to not drink it.
Thanks for explaining. So, I've been playing russian roulette in essence then... and its likely not if I get sick, but when, if I continue this over the "long haul", since the odds are playing against me..
I think I'll find another use for my waste water.
If you wouldn't mind a follow up... is the "community" in general noting that the bacteria load that could be in the water is generally harmless to fish and corals? Seems a bit odd to me that long term storage of water isn't advised against, especially given that the pathogens that could/might be introduced through our water systems may likely be nothing that would occur in the wild in the areas where our animals are native. I mean, pathogens in Iowa certainly have to have different mutations and evolution that those in Fiji, right?
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