Sewage Smells!!

[philkenny]

Hi everyone, 

 

We moved into our new build about 1.5years ago. We are in the country and use a treatment plant for sewage. We are getting a sewage smell outside on the patio's worse some days more than others but particularly bad this summer. I fitted Air admittance valves to the external soil stacks to see if this would fix the problems but smell still there. I am now convinced it is coming form the inspection chamber covers (plastic clarke drain).

Has anyone experienced anything similar, any fixes/suggestions. Have look to see if seals are available but can't find anything, would sealing the covers with silicone be an option? 

[DeeJunFan]

What sort of Washing powder do you use? 

 

There can be a problem with some Biological washing powders and the affect they have on the bacteria in the treatment plant.  

 

May not be your issue but its something to be mindful of. 

[ProDave]

A lot of the plastic drain lids rely on a trough around the edge being filled with water to seal the lid. In this hot dry summer they might have dried out.  Pour a bucket or 2 of water around the edge of each drain lid to see if that helps.

[Jeremy Harris]

You can get plastic screw down covers that have an O ring seal - we have one like that in a path.  It's screwed down with four hefty stainless screws and looks like this:

 

[philkenny]

thanks for suggestions

53 minutes ago, ProDave said:

A lot of the plastic drain lids rely on a trough around the edge being filled with water to seal the lid. In this hot dry summer they might have dried out.  Pour a bucket or 2 of water around the edge of each drain lid to see if that helps.

think ours is this type, will give this a go

[Nickfromwales]

Putting AAV's ( air admittance valves ) on the stacks of the house will CAUSE the problem not solve it . 

Do you have a full height stench pipe on the dwelling ? One that goes to atmosphere ( that you may have then wrongly capped with an AAV ). 

[Jeremy Harris]

FWIW, the pumped air into a treatment plant will tend to create a very slight positive pressure in the foul drains leading to it (it's an extremely low pressure, but enough to push smells around).  Our ground works chap knew about this and suggested fitting the (expensive) O ring sealed, screw down inspection cover, and I'm glad he did.  When the house was empty I forgot to run the taps and keep all the traps topped off, and had a bit of a smeech in one of the bathrooms as a consequence (we have an AAV, to maintain the airtightness in the house).  Easily fixed  - just run the taps and keep the traps topped up, but an indication that you can get smells coming back up the foul drain.

[Ian]

6 hours ago, ProDave said:

A lot of the plastic drain lids rely on a trough around the edge being filled with water to seal the lid. In this hot dry summer they might have dried out.  Pour a bucket or 2 of water around the edge of each drain lid to see if that helps.

You could try filling it with grease instead of water