smelly well water

my water, from a drilled well, sometimes smells. a well contractor suggested it is gas produced by some micro bugs (bug farts?). i’ve dropped some chlorine tablets but the problem comes back.

any ideas for cure or for filter?


Does it happen every fall?

I treat my well once a year. It is a drilled well, 212 feet deep. They do need to be treated once in a while. The head of my county water wells told me this is the easiest way to take care of potential coliform or bad tasting water.

Take the top off your well pipe, pour down a gallon of cheap bleach (not the lemon scented stuff). Run the nearest hose down your well pipe until you smell chlorine coming out of the hose. Turn off the hose and open every faucet in the house until you smell the bleach. Let it sit for 24 hours. At the end of 24 hours, take an outside hose and let it run until you DON’T smell any bleach. Before you open any faucets in the house, remove the aerator screens (dont forget the one inside the washing machine hose) and run the water until you don’t smell the bleach. You should be good until next year.

And since you are on a well, you probably have a septic tank. The chlorine is diluted enough that you should not worry about it affecting your tank.

Did you have your well water tested?

If so, what were the results?

Is the smell more pronounced from the hot water faucet, or is the smell from the cold water or both?

If its from the hotwater side it could be Sulphite reducing bacteria.

Odor is most likely due to the presence of Hydrogen Sulfide

Professional review and conditioning of the water may be necessary.

Would not a simple water sample to the lab for $30 be the loggical start to the finding a solution to the problem?

Just a thought.

Marcel :slight_smile: :smiley:

I have talked with my lab about sulfur (rotten egg smell) in the water. They say that we can smell it before their test will pick it up. There has to be a “large” amount of sulfur for their test to pick it up. They said, if you can smell it, you have it.

not seasonal. why?

have not tested the water, but will be calling the lab to chat.
smell comes from both hot & cold side.
i’ve looked online. apparently there are some sulphur producing bugs. it may be a groundwater leak or just some new source down below. a charcoal filter may take care of it, if the ppm is low enough.


I am under the impression that charcoal filters will only remove chemicals, not bacteria. If its a bacteria problem you may want to check and see if Ultraviolet or ozonation would fix the problem.

If you have sulfur in your well water you can use an Air Induction Filter System to remove the sulfur, I had one installed in my home about 2 years ago from AQUA SYSTEMS works good.
They run about $1500.00.


Hi Andy,

Same I answer I give my clients . You can’t know what it is if you don’t test. Though up this way we do get a lot of iron bacteria which generate hydrogen sulfide as a by-product (that lovely rotten egg/sulfur smell)

So step one is to test. If that’s what yu have the step two is to try an treat the water. It isn’t complicated but it does take a little math to do it properly. Though there is a a good chart in the handout

And while I wouldn’t want to get into an argument over it chlorine in this concentration should not be introduced to your septic. It’s true it probably won’t do any permanent damage but it could. Best not to take the risk.

How to sanitize your well

Testing should be priority on your list. This will tell you where your problem is.

I have a bored well and there is an Oak tree root that grew thru the casing, in the fall when the sap recedes back down to the roots to keep from freezing and damage the tree, it causes an odor. It usually peaks in November then tapers off. After I found out what was going on, I visited many of my neighbors Wells, I could shine a bright light down and see the tree roots also. I had water tested many times and tried every thing I could to no avail, just learned to live with it.

The chlorine will evaporate in three days.

I had a reverse osmosis, ultra violet & water softener installed. Fixed all of my problems. I test my well regularly & results always come back good. Doug

It’s no wonder Doug, you’re D Plummer! :wink: