Septic tank smell in house and outside!

[conmcn]

Hi I am new to the forum so excuse my unprofessional lingo! We moved into a new build house around 6 months ago and noticed a sewer smell coming from under the kitchen sink and outside the back door between the stack pipe and the manhole cover. The smell seemed to be worse first thing in the morning when the plumbing fixtures have been lying idle without any traffic. I checked all the plumbing fixtures under the kitchen sink and everything appeared tight and there was certainly no sign of leaks etc. I then changed the gully outside the kitchen waste water feeds into to a 'u' type gully that holds more water in an attempt to prevent the stink entering, it previously had a gully like the ones fitted to the downpipes and there was always an odour creeping up through the grate. The smell in the kitchen has lessoned a bit but it now smells in the downstairs toilet! All traps seem fine and toilets seals are ok too in the downstairs toilet. I am guessing it is entering via the extractor fan (this is located underneath the stack pipe and exactly where we get the worst of the smell outside. The pitch of the roof is steep and the stack pipe terminates just about a foot above the guttering. Would it be possible that the sewer odour is not getting up and away and is lingering in the pipe and seeping into the house? I have checked the stack pipe and it is not blocked - I put a hose down the top and water is clear to see in the manhole when turned on. I am intending to run some flexi pipe from the stack pipe up along the roof as an experiment to see if it helps this weekend, if it does I will obviously make this more permanent. I just want to know if anyone has any ideas what else it may be? If this does not work I am contemplating getting a new stack pipe further down the sewer line towards the septic tank but am hoping to avoid this as it will take a lot of cutting of concrete and digging etc! Please help as I am at my wits end as how to resolve this, I apologise for my poor plumbing terminology I am obviously not a plumber!

 

[snowhead]

You need to get the builder involved, it appears there may be a blockage underground.

 

[Howsie]

Contact the builder/the people you bought the house from.

 

[leepoll]

Is the septic tank full? Where I live there was someone who didn't bother getting theirs cleaned out for ages and it stunk the whole area out.

 

[kimbo]

The idea of a septic tank is that it should not need emptying and should not smell, the trouble is everyone uses chemicals in the house so that kills the bugs that digest the effluent. |The tank will always be full. A cesspit does need emptying when it is full.

 

[Reg Man]

Bacterial balance in the septic tank not right? Can put chemical bacteria to re-balance and be careful what you put down the drain. Eco friendly substances only.

 

[conmcn]

Hi and thanks for all you replies. The builder is involved and is trying to work out something for us. The first thing I did was get the septic tank emptied a few months ago but the smell persists. Now the temp extension is added to the soil pipe we still get it from the ground level, this makes me think it is coming up via the cast iron manholes, one is in the area where the stink is bad between the back door and the garage. I sealed these with silicone as best I could to keep the smell at bay and to see if they are the culprit. The Mrs cleans the house once a week and does use bleach in the bathrooms but the smell was there just before we moved in and the house had only been rented very briefly previously so I am guessing that is not the problem. I have noticed water running down the outside of the main bathroom waste pipe that the bath, shower, toilet and basin are connected too although this is not the stack. The soil pipe is connected to the downstairs loo and ensuite. Would the poor connects create poor air pressure preventing the stink to travel up the pipe? The builder now suggests an extra stack pipe as the area where the current one is has a high boundary wall, the garage and the house it forms a kind of a courtyard and the sewer gas may not be getting away. Well that's his theory anyway, seems strange it is smelling as bad as it does because I lifted the lids on the septic tank too as it was very bad before I did this. Can someone recommend chemical bacteria (brand name) as per Reg Man's suggestion? I will try anything at this stage! I was also thinking of installing a carbon filter on the stack but this may not work as it appears to be coming from ground level after all. Any help offered is greatly appreciated and apologies if my terminology is a little crude! Oh one last thing I don't think there is a blockage as all the manholes run clear from our house right down to the tank and our neighbours either side (the same builder) do not have a problem with a stink either. The builder told me he fitted a water trap on my tank and can't work out why the smell is coming into the courtyard and house. There is no vent directly on the tank and it is 20m + from the house so I am going to get him to fit one as well while I have him on site. Cheers for all your comments, keep them coming

 

[Gray0689]

Is the pump working ok

 

[conmcn]

Is the pump working ok

Yeah it is working I checked it and it is making plenty of noise. I thought it may have been the soak away being blocked / clogged but the three tanks and linked for the three houses and mine is in the middle so would the smell not enter the house closest to the soak away before mine? I don't know much about it but am trying to rule out each possibility one by one.

 

[Reg Man]

Just Green Septic tank maintenance, Unit 14 Springfield Ind Est Burnham on Crouch Essex CM0 8AU 01621 785088 www.just-green.com

 

[stevetheplumber]

soil pipe should be a metre above the gutter line as well

 

[conmcn]

Thanks for the replies the soil pipe is about two foot above the gutter line at present so will get it raised, it is also at the very end of the line the furthest point from the septic tank. I am assuming that the stink is finding other forms of escaping rather than venting through the pipe and is exiting via manholes and poor plumbing connections instead. Although I still cant work out why it is coming to the house now the lids are off! Reg Man thanks for the recommendation I will check them out, although I live in Northern Ireland so will try and find a supplier closer to home.

 

[conmcn]

Hi quick update I have bought a chemical bacteria solution and have just put some into the system , will have to give it a few days to see if it helps. I have also got the builder to put another stack pipe up closer to the septic tank. Unfortunately it has not appeared to have done any good at all in improving the smell outside the back door, it is still pooling by the manholes adjacent to the original stack pipe. I am at a loss as to how to resolve this our backyard is a mess and we have improved the situation slightly but no real resolution! I am thinking of getting dyno rod round or a similar company to do a camera or smoke test to see if that turns anything up! Again any help you can offer is appreciated as I am at a loss as to how to progress!