Sewage odour

[fullfusion]

Hello all,

Long time reader (posted previously a few times), love the info available here.
Ice recently moved to a new neighbourhood, and my wife has made friends with some of the neighbours. I was recently contacted by my neighbour (single mom 2 kids) asking for help regarding sewage odour in her home.
Upon entering the house the smell was evident, and quiet strong, she was so worried she had previously (2 days ago) called the fire dept in the middle of the night to have them test the air quality for dangerous gas etc (apparently all was good). The fire guys subsequently tried to help out (checked basement floor drains and added water, and for some reason added water to her sump pit). Needless to say it didn't help.
She informed me that she has had 2 plumbers come and have a look and none of them were able to diagnose or fix the issue. Apparently her basement drain has been checked and is clear, and the city has also verified their portion, and found no obstruction or breaks.

I've been told that the basement drain is no longer cast iron or clay and was upgraded to plastic. She has a white plastic (pvc) clean out access under her front porch. But no backflips preventer (or no access was left once the floor was finished if there is one)
I verified all the floor drains (all still had water seal), and all accessible fixtures (sinks etc) in a the basement (unable to visually see water seal in tub but couldn't detect any odour).
I did the same to the remainder of the house verifying all accessible traps and saw nothing out of sorts. I flushed toilets and watched sink traps to see if vaccum was pulling the water seal and again nothing out of the ordinary.

Here is where is gets weird-
She claims the smell is worse on the second (top floor with any plumbing fixture).
She informed me that she has notified the city numerous times and they do nothing, however after enough complaining on 2 occasions they have subsequently sent a vac. Truck to the end of our street and vac out some type of manhole. Apparently this causes the smell to goes away....BUT it returns after six months.

She claims this started 1.5 years ago neighbour across the street re-built his home and eventually had his drain connected to city main.

Any ideas?!?!

 

[Reach4]

How motivated are you? If I buy the external events affecting things (vacuuming out the sewer helping, for example) I would measure the air pressure in her drain lines. This can be done very cheaply. The procedure would be to run some clear tubing through a trap into the drain. Blow to clear any water. A toilet trapway would be one such trap that could be used. That would keep that toilet from being used during the monitoring. Another trapway could be used.

Take the near end, and put it into a glass of water. Normally the level of the water in the tubing should be about the same as the other water in the glass. If there is pressure in the drain air, the water level in the tubing would drop. An inch, at any time,would indicate a lot of pressure. What you have made is called an open air manometer.

If you wanted to set up some kind of alarm for a more rare event, pressure switches that can indicate at less than an inch of water column can be had at moderate prices. The switch could operate a sounder. I would not get excited if that tripped only when somebody flushes a toilet in that house.

You can buy clear tubing easily and cheaply enough. You can also get it free from somebody who uses an oxygen machine at home and throws away a 30 or 40 ft length every month. Cut off what you need.

If that does not show a problem, then I would get some thin plastic drop cloths and some masking tape. Isolate the suspected areas, and see which side of the curtain/barrier the smell is strongest on. Once that is determined, move the plastic to isolate a smaller area.

 

[Sponsor]

 

[fullfusion]

The whole "I called the city and they vac out the drain at the end of the street and it helps the odour in my house 400Ft away" seems like a little much to me, as does the fact that all of this just randomly started right after the city did the sewer connection for the newly built home across the street....then it takes 6 months for the odour to build up again?!?!?

I understand the manometer idea and it actually seems quiet simple other then the fact that I'd literally have to be there on hand to watch the water level in the tubing. If this is the problem, what would the next step towards fixing the issue be???

The smell must have been exceptionally bad today, I realized when I got home from work that she had left her windows open for most of the day, and regardless of the fact that we had unseasonably warm weather today, it seems a little off for January in Canada.

 

[Reach4]

I understand the manometer idea and it actually seems quiet simple other then the fact that I'd literally have to be there on hand to watch the water level in the tubing.

Teach the neighbor to check it, or maybe point a camera at it for a period.

Getting a sensitive pressure switch to activate a loud sound would cost more, but probably under $50.

If this is the problem, what would the next step towards fixing the issue be???

I would think it would be to fix the venting in the house. Dead pigeon in the vent line, or whatever. The venting for the house should keep the pressure in the drain lines about equal to atmospheric pressure.

 

[Cacher_Chick]

I would start by plugging all the drains to see if the smell fades away. We have had places where it was necessary to seal sections of the DVW and pressure test to find leaks in the vent stack in the wall.