Posted on 11/24/2009 7:00:50 AM PST by Alberta's Child
Sorry for the vanity, but I'm looking for advice from someone with a good working knowledge of plumbing issues and I've never been disappointed with the advice I've ever gotten here on FreeRepublic.
A little background . . .
1. My situation involves a finished basement in a small commercial building with a kitchen sink against a wall that is shared with a bathroom. The building was originally designed with the bathroom on a platform that also functioned as a stairway landing. The kitchen is at "ground" level (i.e., on the concrete floor), 2-3 steps down from the bathroom level.
2. The kitchen sink is drained by a Zoeller 105 Drain Pump (to get the water up to the same pipe that drains the bathroom sink).
3. Both sinks drain into a 1.5" pipe. Along this 1.5" pipe, the outlet for the kitchen sink (from the drain pump) is maybe a foot "downstream" from the outlet for the bathroom sink.
Some time ago we began to notice a sewer-like odor coming from the kitchen sink. Not constant, but it was pretty strong when it was observed. I didn't notice any kind of pattern and couldn't do anything to replicate it -- but I did find that when I filled the kitchen sink and drained it, the drain pump would activate 2-3 times and each time it activated a small quantity of brown water (accompanied by a fainter version of the sewer odor) would bubble up into the adjacent bathroom sink.
We had a plumber come and snake out the entire 1.5" line in two segments . . . from the bathroom sink past the kitchen sink to an access valve, and then from the access valve out to the 4" sewer main for the building.
The problem seems to have been corrected for the most part, but I still get a faint sewer odor from both sinks occasionally -- especially in the bathroom when the kitchen drain pump activates.
My question is this:
Is there some kind of chemical treatment I can do in these two sinks that would eliminate odors and perhaps break down grime in the pipes without damaging the drain pump?
I'm looking for something non-toxic that can be simply poured down the bathroom and kitchen drains periodically as part of a regular maintenance/service item for the building -- but it can't be noxious to anyone using the kitchen after it has been poured.
I think you have a Democrat stuck in your pipes........
*GROAN*
Someone else had recommended an enzyme treatment, too — from Home Depot or a similar store. Before I posted this thread I thought this might be a worthwhile approach. I suspect the problem may actually be tied to the low level of use of the kitchen sink — meaning there may be some minor buildup of organic solids (coffee grinds, etc.) in the drain pump tank because the sink isn’t used frequently enough to activate the pump on a regular basis. Even just filling the sink and emptying a couple of times a week may have helped reduce the odor — even without the snaking.
There are P-traps under both sinks.
BTW, I like vanities.
One other thought. If you don’t use these sinks very often the water in the “P” traps can evaporate allowing sewer gases into the house.
Sorry about that. LOL.
REgarding the vent, check to see if the sink trap is still full of water after the sink drains. A clogged vent can cause the traps to be “sucked” dry, letting sewer gas back into the building
Thanks for the heads-up, Kedd. This is a municipal sewer, not a septic system.
LOL, cute!
The pump may have a one way air valve, to prevent it from forming a vacuum, which may have malfunctioned. One thing to check.
There should be no need to pour anything down the drain, as long as there are traps. Do both sinks have a trap?
That could help - if it's coffee grounds, etc. then water movement could help push them through. Might take a bit of water to get around any U-traps, etc. however. If the odour is the main problem, then it's because the stuff is rotting - bacteria are always at work. Bleach or alcohol would kill off most of that.
Probably the best prevention in the future is to avoid putting coffee grounds and other food items down the drain!
An s-trap will leave water at the bottom of the trap to prevent back flow of gases. Don't treat the symptom (odor)...cure the problem.
funny thread. better than talking about Obama. as a girl, I would never dare to handle drains and pipes. however i have done dryer and washer hook ups. mentioned how frustrating it was to a female Army COLONEL i knew. she then told me how her friend, a female AF Colonel, had a frustrating experience hooking up her washer. she said she did what any good woman would do....she sat in the middle of the floor and cried. i can appreciate that.
1. The plumber we use has been servicing the building for years, and seemed to have a good working knowledge of all the elements.
2. I think you're right about this.
3. We'll check the venting if the problem persists, but the fact that the snaking greatly improved it tells me that it is something in the actual sewer pipe, not the vent.
4. Installing another trap might be an idea -- and it wouldn't be hard, since the access valve I described is in a section of the pipe that is accessible through the building's utility room and isn't behind a wall.
5. This was one of my first thoughts, too. Not just that the pump was pumping the line dry, but since the problem appeared when the weather got cold I wondered if the sink wasn't used for several days, then the warm, dry air in the basement (with the heat on) evaporated some of the water in the P-trap and dropped the water level low enough to let sewer vapors escape up into the drain.
6. Yes, the bathroom has a vent fan.
The only sure resolution is to nuke it from orbit...
I’d have to agree. If the “lift station” / lift pump is pumping water past the p traps in the offending sink, then it may be causing enough vacuum to drain them either partially or fully and sewer gas will leak through them. I would plug the kitchen sink drain, fill it with water, let it drain and have the lift pump operate as it normally would, then carefully remove the p trap from the offending sink to determine if there is indeed enough water in it to stop gas from escaping back through it. Also inspect the p traps for cracks and slow leaks (this may be near impossible to detect visually).
If you have metal p traps, give them a *somewhat* gentle squeeze with your thumb at the bottom of the p portion of the trap and see if they cave or flex easily. If so, you probably have a slow leak that can cause this (I just replaced a trap in this condition at my mother in law’s house. I prefer PVC because it doesn’t rot like the thin walled metal p traps and you can usually find a suitable replacement at Home Depot if there’s one near you. Otherwise Lowes or Menards, or any home improvement store along with most major hardware stores should have what you need.
Finally, you may need to install another trap slightly downstream from the trap already there to mitigate this or some other check valve specifically designed for lift pump use.
Not a dumb question at all. I suspect that infrequent use of the sink could be an issue. I wasn’t able to replicate the problem in the kitchen sink before, and I’m not observing anything there right now — so I can’t test the approach you recommended. But I’ll check it out if I notice the problem again. Right now, the only problem I’m observing is an occasional faint odor in the bathroom sink when the kitchen sink is filled up and drained completely.
One of the reasons that a sink will produce noxious fumes occassionaly, is that due to seldom being used, the water in the trap evaporates, and the trap under the sink fails to work as it’s supposed to. Then, the unpleasant odors come up through the trap and the whole place smells like a ceptic tank.
Now, assuming that the sinks both run down the 1.5 inch drain pipe without obstruction, there are two ways to fix this problem. If you have an obstruction, you can either use an enzyme to fix the gunk build up - or do it my way. Buy a container of Rid-X; fill the sinks with warm water, and empty the box of Rid-X in the sink and let it sit overnight. The Rid-X is dried bacteria that keep your ceptic tank working right. Well, the stuff that grows inside your pipe is ‘food’ for the bacteria, so my first plan of attack is to establish a bacterial colony along the pipes to perpeturally keep the gunk under control. Hence the Rid-X. Let the bacteria get going well in the sink, overnight soaking should be sufficient. Opent he drains and let it drain. Bear in mind, bleach and other noxious chemicals kill your bacteria, so don’t use bleach for a week or two. Let your bacteria colony get established. Once established, you can cut the numbers down - but it will be difficult to wipe it out entirely. This is good.
Now for the 2 methods to prevent the sink stink
1. Every week, run a gallon of water into each sink, that will fill the trap with water.
2. If you just don’t use the sink frequently, dump a couple tablespoons of MINERAL OIL into each sink. The Mineral Oil will float above the water, and Mineral Oil does not rot, nor does it evaporate. Assuming you seldom use much water, or pour water down the sink infrequently, this will make and keep a vapor barrier for a long time, with just a little water that you do pour down the trap flowing through the mineral oil barrier, and filling the trap again. If you fill the sink up and drain it, you will flush the mineral oil down the tubes and need to re-treat it. It’s cheap, it’s easy and it only takes a little bit, just enough to make a film of oil between the trap and the open air.
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