Overpowering kitchen sink stench threatens life on earth

May 13, 2007 10:28 AM

My kitchen sink drain stinks! I've tried a couple of different things to fix it, and done some Googling, but the stench remains. Help!

I have a pretty standard deep kitchen sink, with a garbage disposal, from whose drain emanates a foul stink. My attempts to dispel the odor have so far failed me:

1. I've pretty much stopped using the disposal for anything other than light leftover plate scrapings - a few grains of rice or lentils or an errant noodle or two.
2. I've tried filling the sink completely with hot soapy water, then letting it drain while running the disposal.
3. I've tried pouring a kettle of boiling water through it.
4. I've dumped most of a box of baking soda in it.

I'm just assuming that the main reason for this smell is that the inside of the disposal is coated in a rank slime built up over years and years of use by tenants of this apartment who passed before me. I'm just surprised that none of my efforts have been able to eradicate it. If you have a suggestion, preferrably one that doesn't involve taking apart the drain or disposal unit, I'm all ears.

posted by autojack to Home & Garden (20 answers total)

previously I read on here to cut a lemon in half and run it through - i have to take it out, it never gets eaten up -- i usually do both halves too.
posted by thilmony at 10:36 AM on May 13, 2007

I'd use Lye, a more powerful base than baking soda.
posted by phrontist at 10:50 AM on May 13, 2007

chopped up lemons + lots of ice + garbage disposal for several minutes = No more (or at least less) stink.
posted by special-k at 10:51 AM on May 13, 2007

One of those violent drain de-cloggers like Liquid Plumber should get rid of most of that rank slime. Then do the baking soda/lemon routine to get rid of the smell of drain cleaner.
posted by meerkatty at 10:51 AM on May 13, 2007

I now pour a 1/4 L of bleach down each of my sinks, let sit 5 minutes (ie., go visit each sink then go back to the first one), and run lukewarm water for 5 or 10 minutes every month or two (or three).

Seems to keep down incipient clogging (and buildup of slime) and I've never had problems with smell.

For your particular problem, it could have something to do with the central sewer pipe and not your particular unit's pipeage. Do your neighbours have similar problems? If so, maybe it's time to pester the building superintendent.
posted by porpoise at 10:55 AM on May 13, 2007

Does your dishwasher drain into your disposal? I had a similar issue, and I found that the pipe from the dishwasher to the disposal was improperly installed. It was pretty much slanted the wrong way, so crap from the sink was draining into the dishwasher, rotting there, and stinking up the whole place. The solution was to rejigger the pipe so that it drained downward the correct way, from dishwasher to sink.
posted by gaiamark at 11:17 AM on May 13, 2007

the nuclear option (wear goggles for safety if you do this):

one tablespoon of lye in the drain. standing back from it and wearing your goggles, dump a pint of boiling water over it, then step back further.

the lye dissolves in the water exothermically and violently. there will be impressive sound effects (in my sink, it's a churning wug-wug-wug noise) and fumaroles of steam belch forth as a superheated (over 212 degrees fahrenheit) solution of nature's most powerful alkali attacks the bad things in there. there is an element of hazard in this procedure involving hot caustic liquid landing on you so take care, but there was no spitting or spattering on my several occasions. this is the most powerful drain fix i know.
posted by bruce at 11:22 AM on May 13, 2007

Drano foaming pipe snake.
posted by 517 at 11:24 AM on May 13, 2007

baking soda followed by some vinegar should bubble off most of the slime. (though go slowly as you don't want that shooting back out of the drain at you)

once you get rid of the stench, coffee grounds and the occasional lemon will keep things fresh.
posted by wayward vagabond at 11:35 AM on May 13, 2007

Could you poke in a rounded toilet-style brush and scrub it that way?
posted by O9scar at 11:38 AM on May 13, 2007

you can freeze vinegar in an ice cube tray and run a couple cubes through the disposal, and then the lemon to add a final touch. then you can just throw a vinegar cube or 2 through once a week to keep it clean.
posted by lil' ears at 11:44 AM on May 13, 2007

the nuclear option (wear goggles for safety if you do this):

For the record, there's no reason to do this the dangerous way; you could use proper lab procedures and start with the neutral water, slowly add the hazardous reagent (lye), and achieve the same strong base concentration without risking an explosion.

Otherwise yeah, that's basically homemade Drano and it should do the trick.
posted by rkent at 11:45 AM on May 13, 2007

I chuck juiced lemon and lime hunks into a ziptop bag in the freezer. Every so often, I take one out and drop it down the disposal. It's essentially a variation on lemons + ice, and it feels less wasteful to me.
posted by donnagirl at 1:38 PM on May 13, 2007

Where does your kitchen sink drain lead?

When we had this problem we tried most of the above suggestions. Turned out that our pipe ran down, into the crawl space and met up with the sewer. It had been installed on a slight slant, just enough that the food put down the garbage disposal over the years had been able to sit on the pipe, eating through it eventually.

So our crawl space had basically turned into a compost pile without us knowing it - and the smell was coming up through the pipe. We had to have the space professionally cleaned before a plumber would even go close to it.

Which is all to say that the problem may be more than cosmetic. I would suggest that you at least check to make sure all the pipes are in good order. Good luck!
posted by dirtmonster at 2:29 PM on May 13, 2007 [1 favorite]

One possibility, if it's a sewery smell, is a dry trap. The u-shaped bend in the pipe under your sink is supposed to hold water so that sewer gases don't waft into the house. The usual reason for trap seal failure is evaporation when a sink isn't used much, but there are other causes, including leakage, mentioned by dirtmonster. If there's a problem with venting, your trap may not hold water; if there's a string or hair draped around the curve of the pipe, water can drip along it by capillary action and empty the trap -- plus there are four or five more possibilities. You can investigate whether the trap itself is faulty; you'd probably need a plumber to tell you if the problem is in the venting or elsewhere.
posted by wryly at 3:23 PM on May 13, 2007

You can also buy a product at the supermarket called Plink, which is designed for de-stinkifying the sink and garbage disposal. Its not a nuclear option in any way, its just a little capsule of lemony-smelling deodoriser that you grind up every few weeks. My garbage disposal always pongs a bit, and I've found regular use of this keeps it at bay.

I would be very wary of throwing liquid plumbr/lye/acids down there. If its blocked then that's a different matter. Try the lemons, ice or plink first, and if the stink continues then get your apartment management to check it out in case there is a plumbing issue.
posted by Joh at 4:32 PM on May 13, 2007

Easiest way to find out whether the stink is local, or whether it's due to everybody else's sewer gas visiting your home through a dry trap: fill the trap with water by trickling about a litre of water slowly into the drain. Then wait a few minutes for any lingering gases to dissipate, and do another smell test. If there is now no foulness coming up from your sink, but it comes back within half an hour or so, your trap is probably leaking.

If trickling a little water down makes the foulness stay at bay until the next time you empty a good sinkful or dishwasher load, and then comes back almost instantly, there is most likely a problem with the venting on the far side of the trap, making your trap siphon itself empty as the last of the drainage goes through. No amount of chemical warfare will fix that - you need a plumber. But you should be able to work around it until the plumber arrives by trickling enough water into the drain to refill the trap.

Also, if your drain lines are metal, putting violently reactive things down them like hydrochloric acid or drano or lye is not good for them. Plastic drains tolerate those things a lot better.
posted by flabdablet at 6:43 PM on May 13, 2007

My plumber recommends putting ice cubes (no lemon) into the disposal, and then running it (without water), 3 times a week for a couple weeks.
posted by jeri at 2:43 AM on May 14, 2007 [1 favorite]

It's probably a problem with the pipes, not the disposal itself. We had a situtation with a bathroom sink that started smelling persistantly garbagy. It smelled for all the world like it was coming from our drain. Turns out the joint behind the wall leaked and a small pool of fetid water had been building up between the walls.
posted by desuetude at 6:03 AM on May 14, 2007

Strong acids and strong bases are hazardous to you, to the seals and other working parts of your disposal, and to your pipes. How would you like to mix up a batch of industrial strength lye and then find it spraying into your under-sink compartment and onto your kitchen floor?

It's also usually illegal to dump such compounds directly into your sewer line, for the same reasons. And if you put some of this into your pipes and then need a plumber to come work, you will face the option of either exposing your plumber to a nasty, dangerous surprise, versus not being able to find a plumber in the world who will work on the hazardous pipes.

So don't do a dumb thing like that.

Your disposal probably has rotted food stuck in it - off brands of disposal are prone to this problem. I had always gotten a good effect by disposing of a few bowlfuls of quartered lemon skins into the disposal, but friends have told me they've gotten lemon skins stuck in the disposal teeth, which then rotted there and produced a foul stink.

It may just be time for a new disposal. Have you talked to your landlord about it?
posted by ikkyu2 at 10:40 AM on May 14, 2007