Septic Tank - Perculation area question

bob skunkhouse

Hi,

Recently I noticed that the downstairs toilet was 'backing up' so I inspected the outflow from the nearest manhole. When opening it, I could see that it was backed up, moving on through the next set of manifold I could also see this backed up and when eventually inspecting the septic tank (Envirocare system from Kingspan) I could see it was pretty close to the surface - say 60cm or so.
When I got the tank emptied, I noticed that there was considerable water flowing back into the system from the outflow pipe. We drained the tank until the flow was reduced to a smallish enough flow. All this was down about 4 weeks back. I inspected the system again 10 days or so and can see that the closest manifold to the septic tank is now filled again and I'd say I'llhave to go through the whole process again.

I guess the problem lies with the water coming back in from the outflow pipe from the tank.
There's been a lot of rain over the year and from looking at the surrounding fields can see that the ground is pretty saturated - despite the two weeks of good weather during the summer.

Do you think that it's a case of the percolation area just being saturated too, or is there something more sinister at work here.

Any advice is most appreciated.

Bob.

_Brian

Depending on the soil type in your area the ground could be waterlogged and so just not capable of percolating. If you can see water in the fields around them it's not a great sign.

Or your percolation could be silted up blocking the liquid from leaving the system.

You might need to dig down and inspect it to be sure.

bob skunkhouse

Thanks for the prompt reply.

When fencing off the site i did notice that there was shale not too far down, and I can see if from the neighbours site that he's got shale there too. But to be honest, I think it might be hit and miss as when doing some other landscaping I didn't come across it there.

Assuming it is waterlogged, is there any solution to it. I cant be paying 150 bucks every whack about.
It's interesting though. While Met Eireann tells us we've fewer rainy days, I always maintain that the volume of water falling from the sky is greater than previous years. We've had some particularly heavy showers over the past year or so, and one of the local farmers I chat to has also said he's never seen the ground so wet - anyway, I digress.

There is another manhole around the percolation area that I often wondered what it was for. It might be an inspection chamber which would save me the digging.I'll get a look at it over the Christmas period when I've more time.

Are you familiar with the system I'm taking about? If so, do you know if there are 'risers' that can be bought for them? The lid currently sits about 40/50 cm below the current ground level and I'd like to rise it up to ground level and landscape around it so it's not as obvious - if you know what I mean....

Cheers..

_Brian

Not familiar but I know from percolation systems in poorer draining soils it can be a problem, particularly in per longed wet weather.

I don't think the inspection chamber will tell you much, I expect it's a chamber where one pipe from tank branches out to 4-6 pipes in percolation.

If your system backs up again you'll need to dig down to percolation pipes to see if it's silted up or just saturated.

I know many systems where the end of the percolation area drains away to a watercourse to prevent water logging in wet weather where soil percolation is poor. Clay type soils are notoriously bad for percolation.