Bacteria after clorine has been removed?

I have been trying to educate myself about domestic water this past year preparatory to re-plumbing my house, as my past experience concerned only wastewater. I have assembled files full of notes. Often I have been directed by web searches to forums, and I will say that there are more than a few of these notes with Dittohead’s moniker on them.

I would like to take this opportunity to thank Dittohead and all the others, including Gary Slusser and Tom Sawyer for the invaluable assistance they have provided. Whatever amount of success I may achieve in designing and installing my own system, it would not be possible without you. Thank you.

Now, while I am generally loath to offer assistance or advice on these matters due to my obvious lack of experience, I feel I must speak up regarding this chlorination discussion. I do not believe that it is safe to remove chlorine without taking compensating measures. This opinion is based partly on personal, subjective, experience and partly on fact. The fact part is, that without chlorine or some other form of disinfection, you will be fostering colonies of bacteria. This is not disputed. As to whether these bacteria are harmful or not is another question.

I have already mentioned my personal experience with de-chlorination in this thread but I now feel the need to expand on it. The health problems my wife and I experienced (more me than my wife) were chronic and at times moderate to severe abdominal pain. Removing the GAC greatly reduced these symptoms but did not entirely eliminate them. It was not until I stopped ingesting water from the hot water tap that they disappeared. This process took many years.

The conclusion I have drawn is that my ailments were caused by bacteria because they diminished when I reintroduced chlorine to the system and went away entirely when I stopped using hot water to make coffee and cook with (chlorine is evaporated in the hot water heater).

Qualifiers: I use municipal water from a city of 225,000 that draws its water from wells and adds chlorine, not chloramine. My plumbing is copper.

Summation: If you do remove chlorine at POE then do what Dittohead said; disinfect your pipes periodically.

I hope this is helpful, and again, thank you all for a great forum.

- Bruce

I have a similar situation. Well->Chlorination->GAC->Softener->Home (CPVC). Everything's been fine for several years, but recently I noticed a funky odor on the hot side of one bathroom faucet ("my" side of the double vanity, hot water rarely used), and there's a black crud problem in the adjacent toilet, something apparently growing up under the rim. This bathroom is at the end of the line, plumbing-wise, so the water stagnates at my vanity bowl, and in the rim of the toilet, apparently (Toto Drake). The hot water is about 160° at the water heater, so there's no problem at any regularly-used fixture, hot or cold. The other vanity sink hosts the on-demand hot water pump, so the hot side is regularly flushed.

I run the hot water at my vanity once in a while, and that takes care of that problem. I haven't figured out how to chlorinate in the under-rim channel of the toilet yet, but am approximating that by soaking paper towels in a Clorox solution and pasting them up against the rim drains periodically. I'd like to rig up a system to easily chlorinate everything once in a while, but that's way down my list of things to do.

Hot water from a water heater should not be ingested. Present code calls for water heater manufacturers to set the temp at 120f and that is a reduction in the historic temp of 140f which kills all types of bacteria. That reduction was done about 1990 IIRC and has led to many problems with bacteria living in domestic tank type water heaters. One is Legionella, it causes Legionnaire's disease and it can be deadly.

There are two types of chlorine, total and what is left after the chlorine demand has used some of the total and it is called free chlorine. The free chlorine is the part that is able to disinfect the water. If the free chlorine is less than the amount needed (demand), then the water is not disinfected. A water heater that had not seen any chlorine for some time would require a larger amount than the EPA's suggested Free Chlorine residual that water companies should provide their customers.

Normally periodically, setting and allowing the the temp to get up to 140f for 20 minutes kills all bacteria, but that will not be a permanent solution.

Black under the rim of a toilet bowl may be airborne rather than being caused by the water (possibly mold); a pink substance at the water line in pet water bowls and toilet bowls is airborne.

Duplicate post. No delete option for some reason.

A de-chlorinated municipal supply should be treated like a private well system, simple periodic sanitization is important. Also replacing the GAC bed on a periodic basis is important. Many companies give out very bad information on the frequency of their systems, they even try adding copper/zinc media to their systems with ridiculous claims that this will make it last much longer. Properly applied, it will, but sadly that is almost never done. If you check out my personal systems you will see the proper way to incorporate these specialized medias.

Some companies claim 20 year media life on the carbon. This is true in some applications based on chlorine reduction, but they completely gloss over the bacterial growth potential of GAC over time. I have seen GAC filters turn into some of the most bacterial laden filters in a short amount of time due to poor installation locations. The most recent was a filter that was installed right behind a refrigeration unit, the filter was constantly being heated to 100+ degrees, perfect for accelerated bacterial growth. Bacteria comes from many sources, including every time you open the filter housing and don't use proper protocols and sanitary measures to minimize cross contamination. I saw a training video last year that showed the "technician" handling the filter with his bare hands, set the filter on the ground, etc... too funny to watch. Maybe it was my decade of USP and WFI water treatment design and engineering that makes me so anal about proper sanitary techniques. Having to maintain a TOC level below 500 PPB, but actually maintaining less then 10 PPB takes some serious work, proper design considerations, and extensive experience.

The real concern with chlorine in a municipal supply is long term affects on the lungs and more. It may only come in trace amounts, but like anything, long term exposure is where the problems is. I am sure every technician on this site knows how resin and membranes fails over time, and the higher the chlorine, the faster this occurs. Short term, 1 time exposure to chlorine on a membrane or resin has little long term negative affect. It is the constant daily barrage of chlorine. The cumulative math is really quite simple, a one time exposure of 100 PPM, adequate for sanitization, is equivalent to 200 gallons of use at .5 PPM. .5 PPM is not adequate to break up bio-film etc, it is adequate to control the growth only.

The other problem is that GAC is not easily sanitized. That is why it is rarely used in ultr-pure system designs, or when it is, it has a regualar replacement schedule of not morw than 1 year. I have designed a few systems, but I was never pleased with the end results that used heat sanitization of the GAC. I found it excessive and costly.

Hope some of this information helps.

The lower water heater temperatures have not been well addressed for bacterial growth, like Gary said, raising the temperature occasionally is important with the understanding that grave injuries can occur above 125, and very serious scalds occur in only 1 second at 150 degrees.

ditttohead said:

The lower water heater temperatures have not been well addressed for bacterial growth, like Gary said, raising the temperature occasionally is important with the understanding that grave injuries can occur above 125, and very serious scalds occur in only 1 second at 150 degrees.

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One solution is to run the HWT at the higher temp and then use a tempering valve on the output to eliminate the scalding risk. It slightly increases standby losses but provides more hot water without having to upsize the tank.

The folks at Watts recommend setting the water heater at 165 (140 isn't hot enough to kill legionella) and using constant recirculating along with ASSE 1077 devices installed at the point of use.

Yup, heat sanitization is a lot more complex than set the temp to 140 fo an hour and your done. In pharma and commercial applications, 165F for 1 hour is the norm. Many residential water heaters are unable to exceed 150 but fortunately legionellas inside of water heaters is very rare.

In keeping with the subject of domestic tank type water heaters and killing bacteria etc. at 140 F.. And especially what temperature is required, and for how long... I said 140f water temp for 20 minutes. That means the water is 140f (not just setting the heater temp at 140f) and then letting it at the temp for 20 minutes before resetting it to what it was, usually 120f. That causes a thing called pasteurization. 140f is 60 c.

From UNICEF publication, Jan. 2008
While the WHO and others recommend bringing water to a rolling boil for 1 minute, this is mainly intended as a visual
indication that a high temperature has been achieved; even heating to pasteurization temperatures (60º C) for a few
minutes will kill or deactivate most pathogens.

Pasteurization
• Heat water to 65º C for 6 minutes. (65 C is 149 F)
• NOT necessary to boil water.
• Hepatitis A virus is most heat-resistant pathogen.
• Can be very low cost.

See the table of very common pathogens and what temp for 1 or 5 minutes is required to deactivate them at this link.
http://solarcooking.wikia.com/wiki/Water_pasteurization

A... another duplicate post...

Good information. The missing equation is breaking down the biofilm if it occurs. Here is a great article for anyone who has the time and the desire to understand the problems of biofilm. http://pharmatreasures.blogspot.com/2012/01/biofilms-their-associated-risks-to.html This bilogical protective layer is resistant to chlorine and even heat to some degree. High velocities, turbulanece etc are required to effectively get rid of biofilm. Biofilm regularly occurs and the most effective method of removal is steam, Water temperature in excess of 212 F at 0 PSI.

As has been discussed, biological growth in water is normal, natural, and 99% of the time not a health issue, it is when it is never addressed or controlled. If someone has a neglected plumbing system, a known contaminated source, or one that has been sitting for extended lengths of time without water flow, or other factors that can contribute to colony growth, additional measures should be considered.

In all reality prevention is the best method, sanitizing the pipes annually, replacing filters in a sanitary fashion, and properly sanitizing the filter housings and any othe requipment that has been exposed during the maintenance procedure. If biofilm starts to build up, and I am sure many of the service technicians who frequent this site have all seen it, it is very difficult to get rid of effectively.

If you do not have a biofilm presence, then regular heat sanitization or chlorine sanitization methods are very effective and simple to do. If your system is to the point of having a biofilm, usually indicated by a slimy feel to the piping system, longer times, higher temperatures, and running the water at high velocities may be benficial.

FYI, most plumbing systems can not produce adequate velocities to scour the pipes, but maxing out the flow will help. Most residential velocites are around 8-12 FPS, systems that are engineered for heat sanitization and high purity applications are run at velocities in excess of 20 FPS.

Hope some people find this information helpful.

Yeah we are talking removing chlorine on a whole house basis, or not doing so.... now you're off into biofilm.

Seems to me that people should pay attention about biofilm and not remove the chlorine throughout their house since bio film is such a problem and difficult to get rid of.

Personally I would not use such hot water in my plumbing if there was any plastic in the system; such as faucet pigtails/risers, tubing, valves etc. etc.. They do not respond well to water over 100f, remember? Neither does PVC or other plastic drain lines.

Anyway, who are these service technicians who frequent this site that you think you are educating? What, you have them read here because you can't get published in industry magazines?

LOL, cant get published, really? You are truly a sad person. And once again, you are missing the point. You have this weird fantasy that wells are not subject to the same potential problems as dechlorinated municipal supplies. In all reality, the chlorinated municipal supply is typically much safer due to proper and frequent monitoring. Dechlorinating the water at the POE or POU is a simple process that makes the water about as safe, or non safe as a clean well supply. And as stated, residential water heaters are typically not able to get that high anyway, so biofilm issues need to be avoided, but if they do occur, the treatment options are limited. Have you ever seen a bio film issue? Would you know how to porperly treat for it if it were to occur? Oh, I guess you do now...

Keep on trolling.

Yes really. Are you saying I've missed an article of yours in the industry mags? Remember that I know who you are. I don't think I have missed any articles but you can prove me wrong by posting a link to any.

I guess I haven't told you about my experience in well rehab. That included biofilm but, again, the guy with the sickness due to removing his chlorine on a whole house basis didn't have a biofilm problem.

My weird fantasies.... I've never heard of any private well having THMs so I'd like to see your proof that municipal water systems are safer than private residential wells.

LOL, I have never heard of a well having high levels of arsenic, fluoride, radon, Chemicals from industry etc. Heheheh, you must live in a very special place. Your own happy place

ditttohead said:

LOL, I have never heard of a well having high levels of arsenic, fluoride, radon, Chemicals from industry etc. Heheheh, you must live in a very special place. Your own happy place

Click to expand...

I would like to live in that place.

Looks good to me.