LESLIE: Debbie in Ohio has a mysterious odor coming from her son’s bathroom. Are you sure he hasn’t hidden some gym socks in there? (laughing)
DEBBIE: Well, he is a teenager so you never know. (laughing)
TOM: Always possible.
DEBBIE: Yes, absolutely.
LESLIE: So tell us about it. Where do you smell it? What’s it like? What’s … where’s it coming from?
DEBBIE: Well, we built our home about six years ago. And it … we are on a septic tank system. And it is … only seems to be in their bathroom and it’s not all the time. And it only seems to be certain times. And it is distinctly like you would think would be a septic tank odor and I don’t know what’s causing it.
DEBBIE: But …
LESLIE: And it’s a bathroom that you use quite frequently. Obviously, the kids are using it.
DEBBIE: Absolutely, yes. And none of the … we have three other bathrooms in the home and we don’t have that problem with those bathrooms. So …
TOM: Well, generally, if there is an odor problem, it has to do with venting. Somewhere the vent is not properly installed. Or more importantly, there’s no trap. The first place I would be checking would be the sink. Because if there is a trap that’s missing in that area, you’re going to have an open connection to the waste line and that would explain the occasional waft of sewage gas.
LESLIE: And how would you just visually tell, by checking, that there’s no trap?
TOM: Well, when you look under … first of all, when you look under the sink, you want to look for a big u-shaped piece of pipe that goes down and then comes up again. Because that u-shaped pipe is called the p trap and that’s where the water is stored.
LESLIE: So there’s always some water just sitting in the bottom there.
TOM: Right. And hence, that’s why it’s called a trap. Because it basically traps the sewage gas.
LESLIE: (overlapping voices) Because it stops the odor.
DEBBIE: OK. So that could be coming from the sink and not necessarily the commode because we are a septic tank.
TOM: Correct. I mean it’s all part of the same drainage system. All that water goes to the same place. And so, if there’s a trap missing somewhere or if it’s dried out, then that would explain why you’re getting odor. The other place it could be is … you have a tub or a shower in there?
DEBBIE: We have a tub with shower.
TOM: So the other place it could be is in the tub. If you can narrow down which one seems to be the source of the odor, when you start to smell it – kind of maybe do a little nose inspection a little closer and see if you can figure out if it’s the sink or the tub – it’s most likely a problem with the waste system there, not being properly vented and not having a proper trap. And once …
DEBBIE: Not necessarily the commode but either one of the sinks or …
TOM: No, because see the commode is full of water all the time so …
TOM: … it’s probably not the commode.
DEBBIE: Could it be … you know, it’s a double sink. Could it be the sink that they don’t tend to use as often?
LESLIE: It could be. It could be that the trap is dried up.
TOM: Yeah, that’s right. If that trap is dried up, there’s no water in there, it could be as simple as putting some more water in there. OK, Debbie?
LESLIE: So wait, they’re not fighting and they’re sharing one sink?
DEBBIE: Well, one’s off to college now, actually.
TOM: Ah. (laughing)
LESLIE: Oh. I was going to …
DEBBIE: But no, they really did very well. I have to give them credit for that.