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RichK
Ugly odor from kitchen sink
RichK

We live in CT with well and septic. A few years ago we started having an intermittent swamp like odor from the kitchen sink and adjacent dishwasher. It is so powerful that we have had to throw away some dishes & plates that seem to absorb the smell. This smell does not appear in any other locations in the house, laundry room, 2 1/2 baths, outside hoses, etc. Over the years we have bleached the pipes in the entire house more than once. We have replaced the water tank, garbage disposal, kitchen faucet, even the dishwasher as the stink seemed to begin with a hot water load of dishes, now appears to be cold water too. Only in the kitchen sink & dishwasher. We have not bleached the well as the water coming into the house from the well does not smell. We have installed a whole house charcoal filter. We have recently installed a water conditioner as we had a high level of manganese. (No bacteria or other alarming substances detected in 3 separate water tests). We have drained & bleached & rinsed the "boiler mate" hot water tank. The smell always returns no matter what we have done. Sometimes we have a few weeks of normalcy then it returns with no apparent trigger. I'm considering replacing the piece of copper pipe that connects the pipe in the basement to the sink/dishwasher or ripping walls apart to track the vent pipe but these are last ditch efforts. I would appreciate any advice as I'm at my wits end.

Mastercarpentry
Re: Ugly odor from kitchen sink
Mastercarpentry

I think you're going to find the problem where the odor is the highest- the kitchen. First, garbage disposals are notorious for harboring odors and the dishwasher drain probably ties into it. I don't like them on a septic system as what you put in there can upset the microbial balance in the septic tank. I'd pull it down for a 'sniff test' to see if that's where the odor originates. Disconnect the dishwasher drain when you do that, and give that hose the same test. Also look at how the DW drain hose is routed- it needs a high loop between the machine and the drain. Some units have this done on the side of the machine and some don't. If it's not there, then wastewater from the sink and garbage disposal can get into that hose and the dishwasher creating a place for bacteria (and odors) to thrive. I'll bet that's going the be the problem here- it's a more common mistake installers make than you'd think. But if I'm wrong then undo the sink drain and give the outlet piping in the wall a 'sniff test'. If that's where the odor is strongest then it could be bacteria in a pipe which isn't pitched downhill enough, a partially clogged vent pipe, insufficient height of the vent pipe at the roof, or the septic tank itself.

You shouldn't put bleach into a septic tank, nor should you put any acidic or highly alkaline waste into it, nor should you put any grease or iols into it either. That will hinder or even stop the microbes which digest the solids in there from doing their job. And just as insurance, I like to see these given a dose of "Rid-X" Septic tank conditioner twice a year. What it does is feed those microbes so they remain active and that will keep the tank odors down as well as extend the time between tank cleanings. You also need ti make sure everything you put into your drains is safe for septic systems- it will say so somewhere on the label. If nothing is mentioned then you need to do soe research before using that product.

It''s long out of print but one of the best references for septic systems at homeowner level is "Wells and Septic Systems" by Max and Charlotte Alth. It will explain in easy-to-understand terms what goes on in there and what you need to do to keep it working properly, It's not a general-purpose dump but an active biological process that responds to what you put in there and TBH they were never meant to have input from washing machines' garbage disposals, and dishwashers to deal with. Those are better dealt with in a separate 'gray-water' system but that's a while 'nother subject in itself. When built and used properly, a septic system is the most perfect way to deal with household wastewater- even better than the best sewage treatment plants can offer in cleaning and returning the used water to the earth's aquifers. It just requires some care and maintenance that most people aren't aware of anymore.

Phil

dj1
Re: Ugly odor from kitchen sink
dj1

RichK -

Do you have an AIR GAP mounted on the top of the sink, next to the faucet?

bill
Re: Ugly odor from kitchen sink
bill

There is two possible causes,
1) the dishwasher is connected downstream from the kitchen sink, and therefore allows septic tank sewer gas to enter the house.
2) the kitchen sink and or the whole house is not properly vented, allowing the p trap to be siphoned out therefore allows septic tank sewer gas to enter the house.

If you want to fix this for real. call a real plumber he can spot the problem in about ten minutes. the fix might take longer.

Bill

RichK
Re: Ugly odor from kitchen sink
RichK

Thank you. I guess a new plumber is in my future.

ed21
Re: Ugly odor from kitchen sink
ed21

If a double sink, I've found the pipe that slopes over to the trap side tends to build up crud that can stink. Probably grease , oils, whatever that builds up. You can try pouring baking soda down the drains and then vinegar. Rinse with hot water and repeat. You can try drain cleaner too if that doesn't work. Not at the same time though.

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