New house water smell

[birchlake]

Great forum you guys have going here. First time post; been lurking a while.

I have just finished construction of a new house in MN. It has a deep (305 foot; yikes that one hurt the pocketbook!!) well. Water tested at 14 grains of hardness and no iron. Excellent water. The well itself was shock treated twice with chlorine before connecting to the house as the first time it failed for coliform, which I understand is not all that unusual for a 305 foot well. Passed all testing after second shock treatment by the well drilling company. All brand new plumbing including a WaterSoft softener, Marathon water heater.

I'm having an issue with the smell of the water that is coming through the water softener. It has a sulfurish smell. The smell is not overly strong and I wouldn't characterize it as the common "rotten egg" smell that is often described. It is just something that I'd like to eliminate if I can. There is not a taste issue, just the smell.

Important point of distinction here. I have a hard water drinking tap in my kitchen that NEVER has this smell. Ever. This smell is only present at the taps that are run through the water softener. So logically, I think it most likely has to do with the softener. But I know things are sometimes not what they appear to be.

I consulted my water softener owners manual and it recommended that after installation of the softener, approximately an ounce of household chlorine bleach should introduced into the brine well of the softener, followed by an immediate regeneration. So I tried that and after the regeneration was complete, there was no smell! Problem solved I thought. Not so fast. The smell has come back, and it didn't take long.

My plumber still thinks that the smell could be related to the water itself, but if this is truly a water issue, why would I never have this smell at the hard water drinking tap in the kitchen? I've filled pitchers with softened tap water, sealed them and let them sit for extended periods of time, but no smell either.

As I have just moved in and it is not a functional issue, we haven't really dug into this yet, other than my initial chlorination of the softener. Any ideas on what might be the culprit; ie; ways to isolate and resolve?

Would a stronger (2nd) chlorination treatment of the softener be recommended? Or is that chlorine hard on the resin tank? Filtration ideas?
I know how to build a house, but am kind of lost when it comes to the science of water.

Thanks much..........!!

[ditttohead]

A softener should not introduce a smell to the house but as with any water treatment device, bacterial control is of extreme importance. You added bleach to the brine tank but running it through a regeneration may not allow enouh contact time to truly sanitize the resin. Chlorine will damage resin over time so regularly sanitizing the resin is not recommended but resin is cheap, so it is not as big of a deal as many people make it out to be. you can also replace the resin in the future with a chlorine resistant resin that will last through a lot more sanitization cycles.

I would recommend sanitizing all of the plumbing by introducing a 50-100 PPM solution of chlorine into the plumbing. Be sure the softener is bypassed at this high chlorine level. Let it sit for 1 hour then flush. At the same time, add 3-5 ounces of bleach to the brine tank and start the regeneration. Once you smell bleach at the drain, shut the softener down and allow the bleach to work for 1 hour. All protocols for sanitizing with bleach call for a 1 hour contact time to fully sanitize. A standard softener may run the salt and bleach solution through the resin in as little as 10-15 minutes depending on the injector size.

Once the softener and plumbing are fully and properly sanitized, see if this lasts a lot longer.

All water systems will have bacteria, even minutes after sanitization. It is a matter of control.

Controlling bacterial formation may solve your problem. An ounce of bleach in the brine tank every couple of months may work fine. This will damage the resin over time, but depending on the quality of the resin, you should get several years of life out of it. Consider a municipal supply is always feeding approximately 1 PPM of chlorine to the softener, and the chlorine level exiting the softener will be reduced by 20-30%, that chlorine is being consumed in the softener. A well supply has no chlorine, so occassionally sanitizing the system is not a big deal.

[Gary Slusser]

Since the Coliform bacteria problem required the well to be shocked twice, I strongly suggest another Coliform test. And if as I suspect, it is present again, then you need treatment such as a UV light.

[birchlake]

Gary, I certainly could retest for coliform. Easy enough to do. My well drilling company suspected that the reason(s) it needed a second shock treatment was because (1) the depth of the well allows for more potential bacteria from the well drilling equipment, etc. and (2), they may have pulled the testing sample for testing too soon before enough water was flushed through the well. There is no agriculture in this area and they felt that the potential of true coliform contamination would be very low with a 305 foot well.

Dittohead, can you tell a novice how I would introduce a 50-100 ppm solution of chlorine into the household plumbing? Small 1008 sq. ft patio home with only one bathroom.

I keep going back to wondering why I only have the smell in SOFTENED water and not pure well water at the kitchen hard water tap...........

Thanks for your replies.

[ditttohead]

Bacterial odors from a softener are not uncommon if the bed has become fouled. A quick sanitization as the manufacturer recommended may not completely kill the bacteria and recolonization will start all over again in a short amount of time. A real sanitization, which requires a 1 hour contact time if household bleach is going to be used as the sanitizing agent. Resin beds, just like carbon beds are great places for bacteria to grow. This is usually not a problem as the growth is very slow and the physical action of backwashing and brining will usually minimize and control the colonies but if the bed has become contaminated beyond a certain point... a real sanitization may be needed.

I found an old cheat sheet for well sanitization, Gary is right that household bleach may not be ideal for "Shocking" and a cup or two of bleach was too low as well. I hate not having my cheat sheets in front of me. Regular sanitization can be done with

4" well = minimum 1 quart of household bleach per 100 feet of water.
6" well = minimum 3/4 gallon of household bleach per 100 feet of water

Pump this water into your house and you should have a solution around 50-100 ppm. A little higher PPM, up to 200, is fine.

Intermittent, or preventative maintenance sanitaztion procedures are typically very quick, cleaning or removing biofilm or when a know issue exists, a 1 hour soak time is used to guarantee the issue is resolved properly. this is probably overkill, but my past 10 years in USP water systems has got me used to a slower and more meticulous approach.

[Gary Slusser]

Gary, I certainly could retest for coliform. Easy enough to do. My well drilling company suspected that the reason(s) it needed a second shock treatment was because (1) the depth of the well allows for more potential bacteria from the well drilling equipment, etc. and (2), they may have pulled the testing sample for testing too soon before enough water was flushed through the well. There is no agriculture in this area and they felt that the potential of true coliform contamination would be very low with a 305 foot well.

I doubt they were laying their drill pipe etc. on the ground, or enough water didn't flush it out... LOL they are attempting to explain the unknown. I specialized in bacteria testing and treating contaminated wells for all but 20 years. I did a lot for the VA and FHA and all my water treatment customers with wells, which was 99% of my business because I was in a rural area of PA.

You had Coliform bacteria that took two shockings to get rid of and it has nothing to do with the depth of the well. My record is a 605' well that was just drilled and a young family with a 2-3 month old baby. They didn't believe me when my test showed Coliform but a few weeks alter they called me when the baby was deathly ill and the doctor mentioned a water test if they had well water.

You have an odor in the softened water and can't come up with a logical cause. My experience says you need another bacteria test. The sample should be taken at the drain of the pressure tank and only drain enough water to flush out any sediment if any from the valve; you want to know if there is bacteria, not to get a (false) negative/absent result (like some well drillers and real estate agents or a seller).

[LLigetfa]

While it is possible that the bacteria goes as far back as the softener or even as far back as the well, the lack of smell at the untreated faucet does not rule it out. Bacteria can and will build up in large numbers in certain places like rubber or plastic supply lines. I have seen where only one or two faucets in the house exhibit odour. Sometimes it's only the hot water and other times only the cold water depending on what temperature the water is heated to.

[birchlake]

Fair enough. I will get another sample tested. we have a local lab that specializes in it.

I agree that it is important to know what we're fighting here before digging in.

I'll report back when I get the results.

Thanks for your input!

[birchlake]

I stopped by the water testing laboratory this morning and had a discussion with their staff water chemist.

She agreed that I should retest for coliform. She suggested that we use the "membrane filtration" testing method, which yields more specific data (actual numbers) should bacteria be present, as compared to the "colilert" method, which only tells you if you pass or fail the spec.

She also strongly suggested that I test for "sulfate reducing bacteria" which they have found are often related to water smell. She said that if the sample is positive for SRB, that bacteria has not been proven to be harmful to humans.

After talking to her, it makes good sense to have both tests performed So I now have my two sample bottles and will fill them and return them to the lab on Monday morning, immediately after sampling.

One observation that I failed to mention is that during the first month in the new house, I noticed some light black staining of the toilet bowl, which would reoccur after about 3 days after cleaning it. Now I go a week between toilet cleanings and notice no black stains. Also, the smell has become a little less as of late compared to the smell I had a month ago, when it was stronger. Not sure if there is a correlation to that or not, but while online I did see that hydrogen sulfide gas in water can cause black staining of fixtures.

Will be interesting to get the test results. Well worth the $48 total testing cost to know what the enemy might be here........I'll let you know the results!

[birchlake]

I got the test results back from the lab. Negative for coliform and positive for sulfate reducing bacteria at a low concentration, which is not uncommon according to the chemist.

Most likely in the groundwater itself. Could be the well, but keep in mind that the well has had two chlorine shock treatments already. Sounds like this bacteria can be difficult to completely eradicate, but has not been shown to be harmful to humans.

My plumber has been on vacation so I haven't been able to discuss it with him. When we had talked about this a while back though, he brought up a carbon filter as something to consider as the smell is certainly present, but not strong.

Thoughts on this?

[Gary Slusser]

Carbon is hard to beat if you want to grow bacteria... I'd sanitize the softener with a 1/4 cup of bleach in a gallon of water poured into the water in the salt tank (not down through the salt) and wait 15 minutes and then start a manual regeneration and at the end of the brine draw/brining/slow rinse (whatever it is called on your valve) cycle, pull the plug on the softener and bypass it. Wait 20 minutes and put the bypass in service and plug it in and let it finish. Don't use water during all that.

If that doesn't get rid of the odor, repeat.

[birchlake]

Thanks Gary, I'll give your recommendation a try and will let you know the results!

[birchlake]

Sanitized the softener two days ago with chlorine bleach per procedure in Gary's post #11. No smell yet; crossing my fingers that it holds!

I'll update you after some more time passes.......

[birchlake]

Back again with an update.

I performed the softener sanitization procedure that Gary recommended with chlorine bleach outlined in post #11. The smell completely went away for about 8 days. On the 9th day, a slight smell returned. On the 10th day, the softener regeneration took place and the smell disappeared again.

There is no question that the chlorine had an effect on mitigating the odor and also it appears that the softener regeneration seems to help control the smell to a somewhat lesser degree, but do you think there still may be some bacteria in the softener as the odor seems to creep back in after a week or so?

I talked to the well driller and he said that it sounds more like plumbing rather than the well or groundwater, as I never at any time have had ANY smell in the pure hard water drinking tap in the kitchen, only in taps that are served by the softener.

Water test showed positive for low level of sulfate reducing bacteria at low levels though, so maybe this is a ground water issue and for some reason that I don't understand, I just don't get the smell at the hard water kitchen tap?

Certainly making progress here, but would like your thoughts. This is something that I can live with if need be, but the engineering nature in me makes me want to understand it. Thanks!

[Tom Sawyer]

Well I think that you have to figure out if the smell is coming from the softener or from your water source before you can make a decision but, You have chlorinated the softener twice and both times the smell has come back. You shouldn't be getting bacterial growth in the softener that soon so I'd be looking closer to the water. Did you check for hydrogen sulfide?