Catch Basin / Exterior Gutter Downspout Tiles Smell

[Chicago DIY]

Scenario:
1) Sewer gas smell in basement. Floor drains are holding water and I've replenished frequently. Smell is not coming from floor drain.

2) Smell seems to be coming where the foundation hits the footer inside an approximate 3ft section of the foundation. There is interior drain tile in the house attached to a sump pump. No smell from the sump pump or coming from the drain tile going into the sump.

3) Chicago house with exterior drain tiles installed for gutters. Clay

4) One downspout not being utilized...essentially open to the weather.

5) A catch basin was installed when the house was built (1923) however an addition was added on and the catch basin is in a crawlspace.

Question:

1) Is it possible that the non utilized downspout (completely open to the weather is the cause of this smell?

Im assuming the non utilized drain tile drains into the catch basin then into the main sewer line.

I plugged the non utilized downspout last night with a rag and the smell essentially went away.

2) Could the smell be as a result of wind/air blowing into the downspout, through the catch basin and the catch basin pushing air into the basement.

3) What is the purpose of a catch basin? Most of my neighbors in old houses have theirs outside. Mine is in a crawl space. At one time it must have been accessible but an addition was built over it. Do the downspouts drain into it?

4) Lastly, any maintenance I should do to the catch basin? Should I get in the crawl space and run water into it?

Curious on anyones thoughts and apologize for the lengthly post. Im really hoping this was the cause of the smell.

Thanks!
John

 

[Bob NH]

In cities in the 1920s it was common to have combined storm and sanitary sewer systems. They have not all been replaced. Your catch basin may be discharging into a combined system, or into a sanitary sewer. Since it was at one time outside, it may not have any kind of trap, or its trap may be dry.

If it is going to a sanitary sewer, then you need to somehow make an effective trap to stop it from venting under your house, or provide a vent that is high enough that the smell will not collect under your house.

In most cases it is illegal to discharge rain water into the sanitary sewer system.

 

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[Chicago DIY]

Thanks for the quick reply....

One point - the crawl space doesn't smell. do you still think it could be a venting issue?

Thanks!

 

[Bob NH]

1) Is it possible that the non utilized downspout (completely open to the weather is the cause of this smell?
Im assuming the non utilized drain tile drains into the catch basin then into the main sewer line.
I plugged the non utilized downspout last night with a rag and the smell essentially went away.

I'm working from your clues. Anything connected to the catch basin could be a source of the odor, and if the catch basin is covered there might not be a smell under the house.

A smell coming through a crack or joint in the floor could suggest a broken sewer drain underneath. Or it might be a "French drain" connected to the catch basin that is getting gas from the catch basin. You might try to seal the area from which the smell is emanating.

Look into the catch basin and see what runs into it and out of it. It might be some kind of collector sump that collects several inflows and has one outflow to the sewer.

Catch basins usually have a grating on top to admit runoff. Is yours open or covered?

 

[Chicago DIY]

Bob,

Really appreciate the posts regarding my problem.

Today I ended up crawling in the crawl space and opened up the cover. It smelled like sewer once I popped it open. The water also was pretty low.

I ran the garden hose in it for about an hour and it seemed to really help the situation.

I noticed the water rose only to the exit pipe and would not go beyond there.

From what I can see the only thing draining into it are the downspouts from the gutters.

I think the water was low and thus the trap open to the sewer gases. (at least I hope there is a trap?!) the smell definitley stopped once water was added to the basin.

My thought is: I only have 2 of the downspouts connected so very limited water can enter the catch basin. The others are draining off into the yard. We've had very little rain and snow in Chicago this winter and last summer for the most part.

I'll let you know if the smell disappears as a result of this.

Im also going to caulk the foundation where the smell is was coming from.

I have a pic...for some reason I can't figure how to get it below 256K. If you wanna pm me with your email address I can send it to you.

Thanks again...

John

 

[Toolaholic]

Ch Diy

today in SF ,as in the old days, ALL rain down spouts ,are plumbed into the laterals [sewer] if you dumped water onto the ground from your gutters ,you,d be in big trouble with the city. if you have the same situation, the spout lines have sewer gas,as well as the floor drains, i suspect. in sf all the 90 duram fittings sweeping in from outside leaders into the basements and tied to mains are rusted out. i did a complete remodel on a 1927 home 4 yrs. ago. my original home was Boston. things are done different back East

 

[Chicago DIY]

All the houses in Chicago have external downspout drains that tie into the sewer. I think the new construction houses have seperate lines though.

City of Chicago encourages people to disconnect these downspouts and let the water drain onto the yard. However its not possible in all areas.

The big question is: would lack of water encouraged this smell?

My next step is to bring a company in to figure out a solution.

Bottom line the smell has to be tied to the catch basin....no other possibility.

I've got the rough framing almost complete on my remodel and I don't want to go much further without solving this.

I'll keep you guys posted. As of this a.m. the smell is gone.

 

[Bob NH]

The fact that the smell originated from an area in your basement says that some portion of the drain has probably failed in that area. If it was coming from the downspout outside it would have been mixed with air.

Your choices are to find and fix the failure, or to abandon connection to the sewer sump and plug it. You need to be sure you don't plug an active drain from your house.

You probably don't have a trap in the downspout line. It is probably intended to be a vent. In fact, it could be intended as a vent for your sewer system, in which case plugging it could cause a problem. Before you cut off and divert the downspout, verify that you have adequate venting for your plumbing.

 

[Chicago DIY]

I could possibly plug it....it would involve stopping the downspout use.

Im assuming though I'd then have to have the catch basin cleaned to remove all the water in it etc.

My wife and I just bought this house last year A couple times this summer we smelt a sewer smell in the back yard. Im now beginning to think this is all related. Chicago had a extremely dry summer. My guess is since I disconnected the downspouts - Only one was attached at that time...no water was entering the catch basin. In addition several downspouts were not pluged so air was entering it freely.


FYI - its now Tuesday and the smell is gone. I'll keep you guys updated.

Worst case im thinking is I periodically run the garden hose down the one disconnected downspout to add water to the catch basin.